Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~ 334683
S METHOD AND APPARATUS FOR COIN SORTING AND COUNTING
This application is a division of Canadian
Serial No. 607,782 filed Aug~st 8, 1989.
Technical Field
The present invention relates generally to the
1S fields of coin validation and identification and coin sorting
and counting and in particular includes an improved
electronic coin sorting apparatus with novel and improved
coin validation and identification apparatus which also has
utility in the environment of a coin validator.
Background of the Invention
The technical problem solved by the present
invention is the need for high throughput coin identification
and sorting devices. In particular, it overcomes the speed
2s limit~tions of prior art devices in which stepped frequency
generators must be used to sequentially apply a range of
discreet excitation frequencies to an excitation coil in a
ferromagnetic circuit, the response of which will identify a
coin. Similar limitations exist for apparatus which induce
pulses of current and measure eddy current decay
characteristics.
In recent years, significant advances have been
made in the art of coin identification and validation,
particularly with respect to electronic validators. The basic
principles of coin identification and validation are well
~,,~.
2 l 3346~3
known. In the early days of coin operated vending
machines, mechanical devices were used to attempt to
identify and validate coins deposited into the machines.
Some of the earliest machines simply accepted one
denomination of coin and mechanical sizing apparatus was
used to determine if the inserted piece was the proper size
for that coin denomination. Naturally, such devices were
susceptible to the use of slugs.
Later, mechanical devices based on
fundamental kinematics were used to bounce deposited
pieces off surfaces of predetermined resiliencies in order to
validate coin mass. The normal discrepancy encountered
between the mass of a slug of a given physical size and a coin
would cause the coin to bounce through a path through
which it could be tallied, and cause the slugs to bounce to a
coin return path.
Bepinnin~ essentially with the invention of the
transistor, electronic devices for validating coins started to
be used. This trend continued, and expanded greatly as the
circuit density of integrated circuits has increased through
the 1970's and 1980's. In today's world, all electronic
validators accepting multiple denominations of coins are in
common use.
One of the older principles of electronic coin
2s validation is determin~tion of the metallic content of a coin
piece by detecting its contribution to the inductance of an
e~cited coil which is placed physically near the coin during
its travel ~rough the validator. Under these circumstances,
the coin is acting as a metallic core to the coil and effects the
overall terminal inductance seen at the termin~l~ of the
particular coil. Measuring a particular electronic
parameter, such as the m~gnitllde of an alternating current
signal of a particular frequency determines the inductance
of the coil/coin combination in a m~nner which gives
information with respect to the metallic content of the coin.
l 334683
Similarly, various electronic devices for
determining coin diarneter have been used, many of which
employ sequentially masked and ~mm~.~ked photodetectors.
United States Patent 4,086,527 to Cadot shows
an apparatus in which a coin is placed between an excitation
and detection coil to form a part of the electromagnetic
circuit. A sequence of excitation signals, each having a
particular characteristic frequency, is applied to the
excitation coil. The response of the circuit of the output coil
0 is rectified and measured, and compared to a sequence of
values in a look-up table. The match of the pattern of the
output responses is used to determine whether the object
under test is one of a predetermined set of valid coins, or
should be rejected. The Cadot patent also teaches use of the
same meçh~nism to calibrate the device to create the look-up
tables for later use in the validation function.
Another example of a modern all electronic
validator is shown in U.S. Patent 4,509,633 to Chow. The
Chow apparatus employs sets of photodetectors having
beams which cut across the coin path through the validator
and appro~,iate timing circuitry to determine the diameter
of a passing coin. An excited coil is used to detect the
metallic content. Look-up table values for combinations of
coil signal and diameter for a predefined set of valid coins
2s are employed in order to accept or reject any coin piece
inserted into the validator.
Another example of a coin discriminator or
identifier is shown in U.K. Patent Application 2,135,905A
to Leonard et al. The Leonard apparatus uses successively
applied rectangular pulses to pairs of coils adjacent the coin
path in order to determine both metallic content and
diameter. The fundamental principle of the Leonard
apparatus is to excite one of the coils in question which
induces eddy currents in the coin. Once the excitation (a
3s rectangular pulse) is removed, the decay of the eddy
l 334683
currents is measured. Additionally, the Leonard coin
discriminator employs multiple coils of varying diameters.
The eddy currents induced in the coils of differing
diameters will produce different coil outputs as the eddy
s currents decay. In this manner, a sequence of critically
timed rectangular excitation pulses applied to one coil,
combined with measurement-of the decay characteristics of
the eddy currents as detected by another coil, is employed to
use inductive coils to ascertain coin diameter as well as
o indications of metallic content. The approximately
exponential decay rate of the clllr~llt characteristic induced
in the detector coil by the eddy currents is used to classify
the coin. Again, look-up tables of known ranges of values
for coins of specific denomin~tions are employed to
determine the validity and denomin~tion of each piece
passing through the system.
As is known to those skilled in the art, the
primary purpose of coin discrimin~tion apparatus and
typical coin validators, used in an environment such as
vending machines, is to determine the validity and
denomin~tion of the coin so that the total amount of money
deposited at any given time may be calculated to see if the
machine should vend its product or service. In most
vending machine environments, all of the coins deposited
2s are collected in a common collection box. It is well known
that once the coin discrimin~tion apparatus is operated, it is
possible to use the output signals from the discrimin~tor to
physically sort coins into a plurality of receptacles, each of
which is dedicated to receipt of coins of a particular
denomination. Therefore, the coin discriminating
apparatus of coin validators and sorters serve the common
function of discrimin~ting between valid and invalid coins,
as well as determining the denomination of those
determined to be valid.
1 334583
s
The substantial technical problem encountered
in making the transition from coin validation functions to
coin sorting functions is the problem of throughput, or
processing a sufficient number of coins per unit time to
s constitute an efficient sorting process. Coin validating
apparatus, by its nature, tends to be serial in nature, thus it is
normally designed in an environment where coins are
processed one at a time.
Naturally, in the prior art there has been need
0 to sort the heterogeneous collection of coin denomin~tions
which appear in the collection boxes of vending machines
and other devices of the type described above. Usually, as
the coins travel through the stream of commerce, they are
packaged together in convenient collections of like
denomin~tions, such as the well known two dollar roll of
nickels, five dollar roll of dimes, ten dollar roll of quarters,
etc. used in the United States. These are distributed to
business establishments to be used in m~king change. Much
of the change finds its way to vending machines, toll
collection points, and the like where, as described
hereinabove, it is mixed in collection boxes with coins of
various denominations.
Banking operations have a need to both count
and sort large collections of coinage which arrives at
2s various locations in a heterogeneous mixture of
denominations. Other businesses, such as operation of pay
telephones, parking meters, vending machines and others
have large volumes of heterogeneous coin mixtures to
handle.
Most prior art coin sorting devices are
mechanical sizing machines. In other words, they assume
the essential validity of the coins at the input and use varying
mechanical devices to sort the coins by size and thus by
denomination. One example of such a prior art m~chine are
the well known shaker sorters which use trays perforated
6 l 334683
with holes of successively decreasing diameters. Coins will
be provided over the shaker trays at an approximately
predetermined rate per unit time and they are shaken as the
coins travel down the path of the trays. The first set of
perforations will be sized to pass the smallest diameter coin
to block the passage of larger coins. A sufficient distance
down stream from the first set of holes will be a second set
of holes sized to pass the next diameter coin in the
denomination set and used to block the others.
The flow in coins per unit time over the
perforated trays and the number of perforations is
empirically determined so that a very high percentage of the
coins of each denomination will pass through the
appropriate holes into collection bins dedicated to each
denomin~tion.
Additionally, rail sorters are well known to
those skilled in the art in which a pair of diverging coin
carriers are used such that the coins will drop when their
underlying support gives away as a result of the spread of
the rails as coins are passed over them. Also, coin sorters
constructed with a spinning disk onto which the coins are
dropped are known. On such devices, centrifugal force
slings the coins out toward the outer periphery of the disk
and various size exit channels are provided to sort the coins
2s by size.
Once the coins have been sorted, there are
several well known devices for repack~ging them so that
they once again appear in convenient rolls or other
collections cont~ining a predetermined number of coins.
One example of such a coin p~c~ging m~chine is shown in
U.S. Patents 3,707,244 and 3,751,871, to Hull et al. which
are assigned to the assignee of the present invention. In this
apparatus, a large number of coins of the same
denomination are inserted into the interior of a rotating
3s drum surrounded by a vacuum plenum. The drum is
7 l 334683
perforated with a plurality of counterbore locations into
which the partial vacuum within the vacuum plenum sucks
the coins as the drum is rotated. The counterbore locations
rotate past inductive coin sensors which, when a coin is
s detected, activates an air jet to knock the coin into a coin
chutes. In the Hull et al. patent, the output of the coin chutes
includes apparatus for stacking the coins, llltim~tely for
pack~in~ in collections of predeterrnine~l numbers of coins
of the same denomination. Additionally, the apparatus
counts the number of coins detected and forced out of the
counterbore locations into the st~ckin~ chutes. In this way,
the total value of a large collection of coins of the same
denomination can be ascertained as it is packaged.
A principal advantage of the coin packaging
apparatus shown in the Hull '871 patents is its high
throughput, i.e. the large number of coins per unit time that
it can process and package.
Therefore, there is a need in the art for a
dependable electronic coin sorting apparatus having a
significantly higher throughput than that of a single disk
m~hine. Additionally, it is critical that such a machine be
able to not only dependably sort, but to dependably count
- the amount of money sorted since many applications of such
machines are on a service basis, i.e. the operator of the
2s sorter is performing a sorting and counting service for the
owner of the money. A typical example is the service of
sorting coins from pay telephones. Given the significant
throughput of a pac~ging apparatus such as that disclosed
in U.S. Patent 3,751,871 to Hull, it is desirable to use a
structure and coin h~n~lling apparatus of the type disclosed
in Hull '871 in-a dependable coin sorting arrangement.
As noted hereinabove, the discrimin~tor of the
type shown in the Leonard U.K. patent requires multiple
coils in order to identify coin size. The counterbores in the
3s rotating interior drum of the coin packaging apparatus
- 8 l334633
shown in the Hull patent must be sized so that they can accept
the largest size coin of interest, normally a United States
quarter, in the preferred embodiment. Under these
circumstances, when smaller diameters coins are lodged in
s the counterbore, it was a rather trivial problem to detect the
presence of some coin in one of the counterbores when the
machine is fed with input consisting solely of coins of a
single denomination. However, if a heterogeneous
collection of coin denominations is fed into the Hull
o apparatus, the identification problem is exacerbated by the
uncertainty of the particular portion of the counterbore
which will be occupied by a given coin, such as a dime or a
penny, of a smaller diameter than the diameter of the largest
coin of interest.
It is extremely desirable in the art to be able to
process a large number of coins through a coin
discriminating apparatus in a manner which can detect a
coin signature identifying its size and metallic content (and
thus its denomination) using only electronic coils.
Generally, this goal is achieved by the apparatus of the
Leonard discriminator. However, the Leonard
discrimin~tor requires precise calibration and detection of
small differences between similarly shaped exponential
decay curves resulting from the eddy current decay
2s described hereinabove in order to discrimin~te among
coins. The apparatus of Leonard must provide a precision
time base and detect slight differences on the order of
microseconds in the exponential decay characteristics of the
detected eddy currents. This leads to a relatively complex
apparatus requiring precise components for establi.shing the
time base and to more stringent calibration requirements.
Additionally, the apparatus must rotate slowly enough such
that a given coin covers the necessary sequence of coils for a
sufficient period of time to allow the entire sequence of
pulses described in the Leonard apparatus to be applied by
1 3~4683
the coin as it passes over the coils. Therefore, there is a
need in the art for an all electronic coin sorter which can
discriminate coins based solely on coil outputs, but which
device employs a much simpler signature detection scheme
that does not require the precise timing of pulses and
detection of exponential decay characteristics.
Summary of the Present Invention
The present invention is a sensor for
identifying members of a predetermined set of metallic
objects, such as coins, each of the objects having a
characteristic metallic content in a predetermined
geometry. The sensors are of the type having a transformer
coil which includes primary and secondary windings, a
carrier for causing movement of the coins, one at a time,
past the transformer at a substantially predetermined
constant velocity and a memory device for storing a
predetermined set of object identification output signals.
One member of the object identification output signals
corresponds to each member of the set of coins in questions
and there is at least one object identification output signal
which corresponds to an unknown object, i.e., one which is
not a member of the predetermined set of valid coins. The
apparatus includes a signal generator for exciting the
primary winding with an electrical signal and it is
characterized by the electrical signal cont~inin~ at least two
distinct first and second frequency components. which
are provided simultaneously to said primary winding, a
signal processor connected to the secondary winding for
processing output signals into a first signature signal
responsive to the first frequency com~conent in the output
signals and a second signature signal responsive to the
second frequency component in the output signals and a
microprocessor connected to the memory device and the
signal processor for providing one of the object
l 3346~3
identification output signals in response to the two signature
signals.
The present invention fulfills the above
described need in the prior art by providing a coin
discrimin~tion apparatus which is practically usable in the
environment of a high throughput coin handling machine
such as that shown in the above referenced Hull patent.
Because of the use of a rotating drum within the vacuum
plenum, it would be very difficult to dispose coils on
opposite sides of a coin in this type of handling apparatus.
Therefore, it is necessary to be able to test for coin
signatures solely by the use of coils positioned near the
counterbores, but only on one side of the coin.
Additionally, it is impractical, because the
counterbores are disposed along the interior of a plurality
of annular rings which form the rotating drum, to use
photodetector devices and the like to measure coin diameter.
Additionally, a significant problem was
encountered by the inventors of the present invention in
addressing the question of how to detect a valid coin
diameter signature for relatively small coins lying in a
relatively large counterbore, such as the case with United
States dimes seated in a counterbore sized to handle coins up
to the size of United States quarters. This lead to the need to
2s invent an entirely new coin discrimin~ting method and
apparatus which is practically usable in the environment of a
Hull type processing device. Based on the results achieved
by the present invention, the inventors believe that an
enlargement of the counterbores in the preferred
embodiment can lead in a straightforward m3nne.r to a
device which can also sort and count Susan B. Anthony
dollars and U.S. half dollars.
There are two fim~l~mental novel aspects of the
coin discrimination apparatus of the present invention
which allow it to be practically applied to the high
- l 334683
11
throughput environment of a rotating drum coin handler.
First, a novel coiI structure for use in a coin sorting
apparatus was invented which takes the form of a balanced
transformer wound around a common core. The primary
s of the transformer serves as the excitation coil and the
secondary of the transformer serves as the detector coil. In
the preferred embodiment, four separate coils, arranged in
spaced apart pairs wrapped about a common core having a
common longitudinal axis, are disposed such that the lower
pair of coils comprises part of the primary and part of the
secondary of the balanced transformer, and similarly, the
upper two coils are part of the primary and part of the
secondary. In the preferred embodiment, the coil nearest
the path of a passing coin is a portion of the transformer's
secondary and the immediately adjacent coil lying above
same is part of the primary. After a significant space along
the longitll~lin~l axis of the coil is traversed, one meets the
third coil which constitutes the remainder of the
transformer primary. The top coil constitutes the
remainder of the secondary. Ideally, physical embodiments
of the novel coil of the present invention would constitute an
ideal air core transformer. In the preferred embodiment, a
small ferrite bead, movable along the longitudinal axis of
the transformer, is employed for balancing same.
2s The second fundamental aspect of the novel
coin discrimin~tor is its use of an e~citation signal having
multiple frequency coniponents applied simultaneously
which are spaced signi~lcantly apart in the spectrum. It is
known to those skilled in the art that there are significant
non-linearities in metal core inductors. In the present
apparatus, air core coils wound as a transformer are used in
which non-linearities are exhibited in the coil coupling
through eddy currents induced by passing coins.
Essentially, the coil and its associated signal processing
3s circuitry operates as an eddy current detector. At
12 1 334683
frequencies below 4 kiloHertz, the alloy content of the
coupling coin domin~tes the coupling characteristics. At
frequencies above 30 kiloHertz the size of the coin
dominates the coupling, and thus the signal output,
s characteristics. It should be noted that this statement is true
given the constraint that the excitation signal induces an
essentially uniform field across the entire area which the
coin may occupy as it passes the sensing coil. In the present
invention, the transformer coils, described hereinabove, are
sized so that a subst~nti~lly uniform field is created across
the entire width of a counterbore passing the coil as the
drum rotates.
It is known to those skilled in the art that as
frequency of the excitation signal is lowered, under the
lS above stated assumption of the uniform field in the
counterbore, the change in inductance for high frequency
signals is relatively insensitive to the metallic content of a
passing coin. The skin effects tend to appear and the change
in coupling will be primarily due to the size of the passing
coin.
The inventors of the present invention have
applied this knowledge in a novel fashion to produce a
multi-frequency excitation signal which is mixed at the
input to the transformer primary and separated at the output
2s of the detector coil in order to detect contributions of the
output signal from both the high frequency and low
frequency excitations. In the preferred embodiment, the
high frequency excitation is on the order of 100 kiloHertz
and the low frequency excitation is on the order of l.S
kiloHertz.
It is within the scope of the present invention,
and may be required with certain mixes of non-U.S.
coinage, to use frequencies other than the two used in the
preferred embodiment. Additionally, it may be desirable
under circumstances which will be apparent to those skilled
l 334683
13
in the art in light of the present disclosure, to use more than
two frequencies. Additionally, it is within the scope of the
present invention to measure both amplitude peak and width
of the output signals from the detectors at the various
frequencies in order to discrimin~te among coins of similar
sizes and alloy contents, particularly in situations such as the
European market in which a plurality of coinages of
different nations are often found mixed in batches of coins
which need processing.
The inventors of the present invention have
discovered that three basic signature parameters are derived
from these signals which can be dependably used to
discrimin~te among a wide variety of coin denomin~tions.
Like most coin discriminators employing
lS excitation and detection coils, the m~nitllde characteristic
of the output signal of the detection coil will have some
form of characteristic shape as the coin passes, reaching a
maximum m~gni~l~e when the coin is most nearly centered
beneath the inductor. The magnitude characteristic rises as
the coin approaches the center and falls as it leaves the
center. The inventors of the present invention have
discovered that the width of the pulse contributed by the
high frequency signal component and its peak value can be
uniquely correlated to the size of various coins commonly
2s used in modern coinage systems throughout the world. The
width of a magnitude characteristic, as described herein,
refers to the temporal width of the pulse between points at
which it crosses a predetermined threshold in each
direction. In other words, the width of the pulse is equal to
the period of time between the event of the magnitude
characteristic crossing a predetermined threshold in the
positive direction and the event of the magnitude
characteristic subsequently falling below the threshold.
While the preferred embodiment of the present
3s invention detects both width and peak value of the
l 3346~3
14
magnitude characteristic of the detected high frequency
signal, for United States coinage it has been found only
necessary to use the peak value from the low frequency
signal as a signature component. Thus, the present
invention uses a single balanced transformer detection coil
which is excited with two relatively widely spaced
frequency components to detect both size and metallic
content of coins. The detection is accomplished by
separating the high and low frequency signal components at
o the secondary of the transformer and detecting three
signature characteristics. The three signature
characteristics are the pulse width of the magnitude
characteristic for the high frequency component and the
peak value of same, and the peak value of the low frequency
1S component. From these three signature characteristics, it
has been determined that all coins in a typical coinage
system, such as United States pennies, nickels, dimes, and
quarters, half-dollars and dollars can be reliably identified.
As was the case in the apparatus of the Hull
patents, id., jets of compressed air are used to blow a
detected coin out of the counterbore and into a coin
receiving conduit for collection or p~ck~ing.
In the preferred embodiment of the present
invention, the Hull apparatus has been modified so that six
2s distinct coin conduits are disposed within the interior of the
rotating dmm subst~nti~lly parallel to the axis of rotation of
the drum and perpendicular to the direction of travel of the
counterbores. Since each conduit is dedicated to receipt of
coins of a particular denomin~tion, appropriate timing
circuitry is provided to activate a co.l.~ssed air jet over
the a~lop.iate coin conduit when a coulltelbore cont~ining
a coin of the a~ro~liate denomin~tion becomes registered
thereover.
In the preferred embodiment, there are ten
3s annular rings containing 40 counterbores each which
15 l 3346~3
comprise the rotating drum within the above mentioned
vacuum plenum. Therefore, the preferred embodiment has
a rank of ten like coils set above the rotating drum. Down
stream, in the sense of the direction of the drum's rotation,
si~ ranks of solenoid operated air valves are disposed over
the six respective coin conduits. Therefore, there is one
solenoid operated air valve over each coin conduit for each
rotating annulus of the drum. A seventh rank of air valves
is provided to return coins to the interior of the drum under
circumstances described hereinbelow.
Additionally, the present invention employs a
set of lag sensors which are downstream from the air valves.
The lag sensors need only detect whether or not a metallic
coin is present in a manner similar to the detectors used in
the Hull coin packaging apparatus. Since the ability to
reliably count coins is an important function of this
apparatus, the lag sensor is used to confirm ejection of a
coin by the solenoid operated air valves when same is
operated. Therefore, for a given denomin~tion of coin
detected at a particular counterbore location, the
a~royriate air valve will be operated as the counterbore
location passes over the appropriate coin conduit.
Subsequently, this counterbore position will approach the
lag sensor and the machine tests to see if a coin is still
present. If the coin is not present, this is taken as
confirmation that the air jet from the solenoid operated
valve was successful in ejecting the coin from the
counterbore into the conduit and the tally for that
denomination is incremented. If the coin is still present, no
incremP.nting of the coin count takes place.
It is, of course, possible to include an additional
lag sensor intermediate each of the air valves in the
preferred embodiment to detect the presence of an air valve
which was stuck in an open position. However, the expense
of the additional sensors and the accompanying requirement
l 334683
16
of physical spreading of the sensor/air valve array on the
apparatus does not, in the opinion of the inventors, justify
the additional expense. It is desirable to periodically test the
condition of the valves by operating the apparatus in a mode
s in which all of the air valves are activated, and subsequently
introducing coins into the apparatus, detecting the presence
of same in a particular counterbore location, and testing for
the presence of a coin at the lag sensor with none of the
valves being operated. If the absence of a coin is detected in
o a particular channel, it is an indication that one of the air
valves over that channel is stuck in an on position and is
c~lsin~ continuous and ~ ;..te .~le~l ejection of coins.
It is further known to those skilled in the art
that the proximity of the coin to an excitation and detection
1S coil structure will significantly affect the magnitude of the
output signal from the detector coil in inductive type coin
discrimin~tors. In the present invention, the rank of
detector coils is located at a particular position very close to,
but lying above, the outer surface of the rotating drum.
Since the drum is relatively large, very slight irregularities
in the axis of rotation can cause significant differences in the
space between the detector coil and different counterbore
positions along the same ~nmll~r ring. In other words, if the
drum is rotating slightly off axis, it will tend to wobble
2s somewhat and certain of the counterbore positions will pass
- very close to the coil while counterbore positions on the
opposite side of the ~nnl~l~ls will be spaced farther from the
coil. Naturally, this could have a tendency to cause
inaccurate or unreliable analysis of the signatures obtained
as the same coin passes the same coil. In other words, very
slight mechanical imperfections in the drum rotation can
lead to significant deferences in the signatures under
conditions which are otherwise identical.
In order to counteract this possibility, the
3s preferred embodiment of the present invention calibrates
1 334683
-
17
each counterbore position prior to operating the machine as
a sorter. In the calibration process, a batch of coins of
known denomination is inserted into the rotating drum. It is
known to those skilled in the art that even coins of a
s particular denomination within a particular coinage system
will have different signature characteristics due to varying
states of wear and changes in metallic content at the time of
minting which occur over the years. During calibration, the
values for the signature signals described above are read as
each counterbore position cont~ining a coin passes the coil.
The above referenced seventh rank of air valves blows each
coin back into the interior of the drum where it will
eventually become relodged in a counterbore position.
Operating the apparatus by this method for a period of
S several minutes assures that each counterbore position is
provided with a representative sampling of the coins of the
particular denomin~tion being calibrated. High and low
values for the signature signals are stored in memory during
calibration and used, for each counterbore position, when
the m~chine is subsequently operated as a sorter.
As noted above, there is a seventh rank of
solenoid operated air valves downstream from the last rank
of valves over a coin conduit. Operation of one of these air
valves blows the object in the counterbore back into the
interior of the drum. These air valves are used both during
the calibration process described hereinabove and to
dislodge objects representing unknown sort values during
operation of the machine. At this point in time, it is
appropriate to introduce some of the terminology used in
this specification. When the difference between detected
signature values for an object in a counterbore position and
the range of signature values for valid coins is sufficiently
large, the apparatus makes a determination that the object is
"off sort" and thus treats it as a bogus coin. Thus,
references to an off sort value refer to a detected object
1 334683
18
which generates signature values which are so different
from valid signature values that the object is ejected into a
coin conduit dedicated to bogus coins and off sort objects.
A set of signature signals which are close, but
S not within the range, of any valid set of signatures is
referred to as a "unknown". During operation of the
m~chine, the valve associated wi~ that particular ~nnllhls in
the last rank of valves is operated when the particular
counterbore containing the unknown object passes
thereunder. In this way, the object is normally dislodged
and blown back into the interior of the machine. There is a
high probability that it will subsequently find its way to
another counterbore. It should be noted that ~is operation
increases the probability that a valid coin having metallic
1S and size characteristics which are very marginal, will be
properly sorted as a valid coin. If its signature
characteristics are only slightly outside the range for a
particular counterbore location, it is quite possible that they
will fall in the range of signature characteristics for a
different counterbore location in which the coin
subsequently becomes lodged. Also, unknown values can be
generated in the rare, but not impossible, event that a coin
becomes lodged in the counterbore in a skewed fashion in
which one edge of the coin is caught on a sidewall of the
2s counterbore. Under the circumstances, the coin is not
properly seated in the bottom of the counterbore well and
will fail to produce appropriate signature signals, although
they will normally fall within the unknown range rather
than the off sort range.
It should be noted that in practical applications
of the preferred embodiment, a very small number of
unknowns are encountered. The unknowns are preferably
defined in the present invention to provide a very accurate
sort and count.
18a 1 334683
Notwithstanding the above details about various aspects of the
invention disclosed herein, the invention claimed in this divisional applicationprovides a coin handling apparatus of the type including a rotating cylindrical drum
having an axis of rotation and having a plurality of counterbores disposed in a
5 plurality of channels Iying in planes perpendicular to the axis of rotation, each of
the counterbores having a hole therein. A cylindrical housing surrounds the
rotating cylindrical drum to form a plenum between the inner surface of the
rotating cylindrical drum and the cylindrical housing, and a pump creates a partial
vacuum with the plenum such that the air pressure within the rotating cylinder is
10 higher than the air pressure at the outer surface of the rotating cylinder. There is
means for rotating the cylindrical drum within the cylindrical housing in a
predetermined direction of rotation. The apparatus is characterized by an array of
coin sensors disposed on the cylindrical housing such that at least one of the coin
sensors is located over each one of the channels, and a plurality of elongated coin
15 receiving stations are located within the cylindrical drum along lines parallel to the
axis of rotation. An array of selectively operable air valves is disposed on thecylindrical housing such that at least one of the air valves is located substantially
over each of the coin receiving stations for each of the channels. Coin
identification circuit means is connected to the array of coin sensors for providing
20 a particular coin identification signal from a plurality of coin identification signals
in response to each occurrence of a metallic object lodged in one of the
counterbores of a particular one of the channels passing the one of the coin
sensors located over the particular one of the channels. A controller is connected
to the array of air valves and the coin identification circuit means for providing an
25 activation signal to a particular one of the air valves located over the particular one
of the channels in response to the particular coin identification signal to cause the
metallic object to be ejected into a corresponding particular one of the coin
receiving stations.
,,
1 334683
19
As will be appreciated by those skilled in the
art from the description to follow, the coin discrimin~tion
method and apparatus described herein has utility in coin
sorting and validation devices other than those of the type
disclosed herein.
Brief Description of the Drawings
Fig. 1 is a pictorial view of the coin sorting
apparatus of the present invention and associated machinery
0 constituting its preferred environment.
Fig. 2 is a pictorial view of the interior of the
rotating drum of the preferred embodiment showing the
coin accepting counterbores.
Fig. 3 is a pictorial view of the coin discharge
paths of the preferred embodiment with certain elements
shown in phantom.
Fig. 4A is an elevated section view showing a
typical set of counterbores rotating past the novel detector
coil of the preferred embodiment and showing the coil in
cross section, appearing with Figure 2.
Fig. 4B is a circuit diagram of the preferred
embodiment of the detector coil of the present invention.
Fig. 5 is a diag~ tic projec~ion of the array
of sensor coils and air valves used in the preferred
2s embo-liment of the present invention.
Fig. 6 is an elevational section view showing
the rotating cylindrical drum under the array of air valves
in the coin receiving stations in the interior of the drum.
Fig. 7 is a block diagram of the controller and
signature acquisition circuitry of the preferred
embodiment.
Fig. 8A is a circuit diagram of the oscillator
board of the preferred embodiment.
Fig. 8B is a circuit diagram showing a portion
3s of the connector board of the preferred embodiment.
20 l 3346~3
Fig. 8C is a block and circuit diagram of a
representative one of the proximity/valve boards of the
preferred embodiment.
Fig. 8D is a block diagram of the analog
s circuitry of the signature detection apparatus of the
preferred embodiment.
Fig. 8E is a block diagram of the proximity
detector circuits of the lag sensors of the preferred
embodiment.
Fig. 9 is a graphic representation of output
voltages of the signature signals used in the preferred
embodiment.
Fig. 10 is a diagram depicting particular
memory locations and the coin ejection queue of the
memory of the preferred embodiment.
Fig. 11, consisting of Figs. llA through llE
show various states of the coin ejection memory queue for a
typical example of a sequence of detected coins of particular
denominations in two adjacent counterbores for one channel
of the preferred embodiment.
Detailed Description
Turning now to the drawing figures in which
like numerals reference like parts, the preferred
embo~lim~nt of the present invention will now be described.
Fig. 1 is a pictorial view of the apparatus of the
~felled embodiment and the associated equipment used in
its preferred environment. The coin sorter of the present
invention is generally shown at 20 in Fig. 1. A conventional
clç~ning station is shown at 21 and is the location into which
coins are initially deposited during processing by the
apparatus. Cle~ning station 21 is conventional in nature and
is not, per se, part of the present invention.
Coins which leave the cle~ning station 21 are
lifted by a slat conveyor 22 up to an input chute 25. Coins
`~ l 3346~3
21
from the input chute 25 are carried by input chute 26 to the
interior of a rotating drum, described in further detail
hereinbelow. The above mentioned drum is rotated by a
motor 27, the output of which is coupled by a belt 28, shown
in phantom in Fig. 1, to the exterior of the drum. One end
of the drum cont~inin~ chamber is sealed by a clear Lexan
polycarbonate plastic window 29, with an opening at 30,
where input chute 26 passes through window 29.
An operating console 40 is also shown in
Figure 1. The console includes a CRT 41 which is used in
monitoring performance of the machine and a keyboard 42
- used for controlling the apparatus. One print station puts
out conventional eight and one half inch wide paper shown
at 45 which is used for report printing, and providing
technical data during service and maintenance.
Additionally, a smaller printing device 46 is used for
m~king hard copy of tabulations of particular sort runs
which may be provided with the collected sorted output of
coins from the m~chine.
An array of 70 solenoid operated air valves is
disposed about the upper portion of the periphery of the
chamber in which the drum rotates. The array is generally
indicated at 31 in Fig. 1. The lag sensing coils are also
visible in Fig. 1 and are indicated generally at 32 in the
2s drawing figure.
In the preferred embodiment, each of the
solenoid operated air valves shown at 31 has a twisted pair
of conductors attached thereto for operating the solenoid.
These are omitted from the drawing of Figure 1 for the sake
of simplicity. Likewise, output leads from the proximity
sensors shown at 32 are also omitted from the drawing
figure.
As noted hereinabove, the coin sorter
apparatus is physically constructed in a m~nner quite similar
3s to that of the apparatus shown in the above referenced
l 334683
,_
22
U.S. patents to Hull et al which may be
referred to for further details. Therefore,
details of the vacuum plenum and the rotating
drum containing a plurality of counterbores.
may be understood by reviewing the above
referenced Hull patent. For the sake of completeness of this
specification, a few details of same will be pointed out.
Turning next to Figure 2, a pictorial view of
the drum S0 is shown. The drum is constructed of ten side-
o by-side annular channels Cl through C10, eight of which are
visible in the drawing of Figure 2. Each channel has a
predetermined number, forty in the preferred embodiment,
of equally spaced counterbores Sl about the periphery of
the ~nn~ r segment. Each of the counterbores is identical,
and all counterbores are referred to by the common
reference numeral 51 herein. Each of the counterbores Sl
has a centrally located hole 52 which passes all the way
through the channel to the outside of the drum.
In the same manner as the apparatus of the
20 above referenced Hull et al. patents, the drum is rotated
within a plenum in which a partial vacuum is maintained
during operation. Therefore, the pressure on the outside of
the drum is lower than that on the inside and air tends to
rush from the interior to the e~terior of the drum through
25 holes 52. During operation of the apparatus, the partial
vacuum created by the plenurn (not shown) causes coins to
become seated on the floors of the counterbores 5 l .
As indicated in Figure 2, each of the channels
has forty counterbores spaced around its periphery. The
3 0 center lines of the counterbores for each channel æ aligned
along a line parallel to the axis of rotation of the drum such
that adjacent counterbores on adjacent annular channels
form rows of counterbores. The rows are numbered Rl
through R40. Thus, the counterbores disposed on drum S0
35 may be thought of as a rectangular matrix of counterbores
having ten columns and forty rows, all of which are
1 3346~3
23
wrapped around the surface of a cylinder with row one
being adjacent to row forty at the location where the
rectangular array is joined, end to end.
The definition of any given row as row one is
arbitrary, and is defined in the preferred embodiment by a
master timing mark (not shown) which defMes the first
row. The master timing mark is detected by photosensitive
devices in a manner which is conventional, and well known
to those skilled in the art. Additionally, timing marks (not
shown) are located at every row such that they occlude the
photodetector of an optocoupler when a given row of
counterbores is aligned with a coin sensor, as explained
hereinbelow. Again, the use of such devices for
synchronizing external digital control circuitry to
mechanically rotating equipment is conventional and well
known to those skilled in the art.
Figure 3 shows certain details, some of which
are depicted in phantom, of the interior of the mechanism.
It also shows certain aspects of the preferred embodiment
which differ from the details of the apparatus disclosed in
the Hull patents. The vacuum plenum in which drum 50
rotates is supported at one end by end cap 55. It should be
noted that the proximate end of the drum apparatus shown
in Figure 3 is the opposite end of same from that depicted in
2s Figure 1. As may be seen in Figure 3, counterbores 50
rotate over a plurality of coin receiving stations 56a through
56f. The top openings of stations 56e and 56f are visible in
Figure 3 where a portion of drum 50 is broken away. The
coin receiving stations 56 each feed a coin receiving conduit
having a slanting bottom generally shown at 57 in Pigure 3.
Each of the coin receiving stations 56 is in turn coupled to
one of six coin output conduits 58a through 58f shown in
Figure 3. The assembly of the coin conduit apparatus passes
through a second Lexan window 59 shown in Fig. 3.
- l 334683
24
A typical row of solenoid operated air valves is
shown at 61d in Figure 3. The seven rows of air valves are
designated 61a through 61g in this specification and it will
therefore be appreciated that row 61d is over the fourth
coin receiving station 56d. As noted hereinabove, the
seventh row of air valves 61g (not shown in Figure 3) is
located along the periphery of the housing over drum 50
such that coins blown out of counterbores at that location
are returned to the interior of drum 50.
A typical valve is shown at the distal end of row
61d and includes a solenoid 65 and an air jet 66. Each of
these devices controls a valve (not shown) which couples
pressurized manifold 67 to its associated air jet 66. A
source of compressed air (not shown) is connected to
manifold 67 such that activation of solenoid 65 will cause
compressed air to rush through air jet 66. This occurs when
a respective one of holes 51 is directly under the bottom end
of air jet 66, and any coin lodged in the counterbore 51
associated with the hole 52 will be blown into coin receiving
station 56d.
A deflector plate 68 distributes coins entering
the interior of the drum from input chute 26 along the
length of drum 50. A level switch (not shown) controls the
slat conveyor which controls the rate at which coins are
2s introduced into the drum for agitation and deposit in the
counterbores.
It should be understood that air jet 66 from the
solenoid operated air valves pass through the exterior (not
shown) of ~e vacuum plenum. The points at which the jets
66 pass through the plenum wall are made appropriate
airtight. Thus, the solenoids 65 sit on the exterior of the
drum apparatus as shown in Figure 1 and the air jets 66
termin~te in the interior of the vacuum plenum just over the
rotating outer surface of drum 50.
l 3346~3
Figure 4A is a cross-sectional view showing the
preferred embodiment of the sensing coil 70 and an arcuate
segment of rotating drum S0. The section is taken through
the center line of the coil and the center line of a typical one
of the annular ch~nnels of the drum S0. Three exemplary
counterbores Sla through Slc are shown in cross-section,
each of which has the characteristic centered hold 52 bored
through the center of the counterbore to the outer surface of
the drum.
Physically, coil 70 includes four coils 71
through 74 wound around a bobbin 75 constructed of
material of very low magnetic permeability. In the
preferred embodiment bobbin 75 is made of Dekin plastic.
The coils are arranged in pairs such that coils 71 and 72 are
S wound around the lower portion of bobbin 75 and coils 73
and 74 are vertically displaced therefiolll. The coils 71
through 74 are wound perpendicular to longitll~lin~l axis 76
of the bobbin. In the preferred embodiment, each of the
coils 71 through 74 is constructed of approximately 200
turns of 32 gauge copper m~gnet wire.
Longitudinal axis 76 also-defines a center line
for a threaded hole, shown at 77, which passes through the
length of the bobbin. Journaled within hole 77 is a threaded
ferrite bead carrier. The m~ting threads on hole 77 and
bead 78 allow the carrier to be positioned longitudinally
between coils 72 and 73. As may be seen from inspection of
Figure 4A, the ferrite bead is a fairly small mass of
magnetically permeable material and its purpose is only to
make minor adjustments in the balance between the two
secondary coils. If coils 71 through 74 were perfectly
wound, the sensing coil would approximate an ideal air core
balanced transformer and there would be no need for the
bead.
Figure 4B shows the electrical equivalent
3s circuit of sensor coil 70 shown in Fig. 4A. The input
26 1 3 3 4 6 83
primary port is shown at 80 in Fig. 4B and the output or
secondary port of the balanced transformer is indicated at
81. As may be seen by the concurrent inspection of Figs.4A
and 4B, the inner two coils 72 and 73 of the physical bobbin
S form the primary of the balanced transformer and the outer
two coils 71 and 74 form the secondary. In Fig. 4B, the
transformer is indicating as having a variable metallic core
at 78 which is embodied by ferrite tuning bead 78 shown in
Fig. 4A.
In cross sections perpendicular to longitudinal
axis 76, bobbin 75, and thus coils 71 through 74, are
rectang~lar. In Fig.4A, the cross section is taken parallel to
the shorter side of the rectangle. Since the width of the
bobbin, and thus the coils, is approximately equal to the
1S diameter of counterbores 51, it will quickly be appreciated
that the length of the rectangular coils is significantly
greater than the diameter of the counterbores. The
combination of the electrical arrangement shown in Fig. 4B
in the above described geometry of the coils and bobbin has
been found to give extremely good results in a non-contact
coil sensor which can discrimin~te both coin size and alloy.
First, it is important that the induced field be subst~nti~lly
uniform across the entire area of the floor of a counterbore
51 when it is centered under a coil 70. Thus, coils of other
2s geometries can be used to construct embodiments of the
present invention but a coil having a rectangular bobbin
with an aspect ratio of approximately 2.75 of the inner
dimensions of the bobbin has been found to give what the
inventors believe are the best results and practical
embodiments of the present invention.
In the preferred embodiment, bobbin 75 is one
inch wide (the horizontal dimension shown in Fig. 4A) by
1.6 inches deep by 2 inches high, the vertical dimension
shown in Fig. 4A. The exterior of coils 71 through 74 are
27 l 334683
indented slightly from the outer wall of the bobbin and are
sealed in plastic.
The effects of this geometry in the above
described constraint on the field across the counterbore will
s now be briefly described so that the inventor's solution to
the problem of indeterminate coin positioning within the
counterbores may be understood. Three exemplary
counterbores 51a through 51c are referenced in Figure 4A.
As noted above, the counterbores of the preferred
embo~liment have a diameter which is only slightly larger
than the diameter of a U.S. quarter. Naturally, the only
requirement for the present invention is that the diameter of
the counterbores be large enough to accommodate the
physically largest coin of interest in a set of coinage or
tokens with which the device will be used. In the example
shown in Fig. 4A, counterbore Sla has a U.S. quarter seated
therein, counterbore 51b has a U.S. nickel seated therein,
and bore 51c has a dime.
The case of the quarter is relatively trivial
because it will be centered in the counterbore as a result of
the above described size of same. However, the cases for
physically smaller coins require the inventors of the present
invention to make sure that the problem of indetermin~te
positioning of such coins within the counterbore could be
2s dealt with successfully. First, the problem will be apparent
to those skilled in the art that a coin having a radius r2
smaller than the radius rl of the counterbore may have its
center located anywhere along a locus of points constituting
a circle of radius rl - r2 centered at the center of the
counterbore. Additionally, the center of the coin may be
located anywhere on the circle of radius rl - r2 or anywhere
within the circle.
The indeterrnin~te position of the smaller coins
leads to the result that the coins may have their centers
3s positioned ahead of or behind the center of the counterbore
1 3346~3
28
aligned with a longitudinal axis of hole 52. Thus, the coin
will be displaced laterally from a tangent to the surface of
drum 50, passing through hole 52 and pointing in the
direction of rotation of the drum. In other words, the
s displacement of the center of the coin from the center of the
counterbore may have a significant component parallel to
the axis of rotation of the drum.
Also, smaller coins may be displaced ahead or
behind the center of the counterbore with respect to the
o direction of rotation.
The former displacement leads to the practical
requirement that the long side of the rectangular geometry
of coils 71 through 74 be sufflciently long so that the lateral
position of a small coin within the counterbore will not vary
1S the electromagnetic effect of the coin passing under the coil.
Those skilled in the art will appreciate the need to increase
the length of the long side of this rectangular geometry so as
to prevent boundary conditions from varying the electrical
response, which would have a significant impact on the
electrical response to, for example, a U.S. dime centered in
the counterbore and a U.S. dime displaced laterally by a
distance rl - r2. Therefore, the problem of inconsistent
response to smaller coins which results from lateral (with
respect to the direction of rotation) displacement of the coin
2s from the center of the counterbore is overcome by the
increased width of the rectangular shape of coils 71 through
74.
A U.S. dime which is displaced along the
direction of rotation of the dNm is shown seated in
counterbore Slc at Fig. 4A. If it is assumed for the moment
that the dime is laterally centered within the counterbore, it
will be apparent that the aberration in the m~c~ine response
will be solely a function of the timing of the electrom~netic
impact of the coin's passing. Since the center of the coin in
3S this case is traveling ahead of the center of the counterbore
29 l 334683
by a distance rl - r2, it is important that the signal processing
circuitry be insensitive to this jitter between the temporal
locations of the peaks of the pulses produced by the passing
coins. In the preferred embodiment, two parameters of the
machine assure that this result is accomplished. First, the
spacing between adjacent counterbores within any one of the
~nn~ r channels, indicated by dimension line ~2 in Fig. 4A,
is sufficiently greater than the maximum displacement
between the center of the coin and the center of the
lo counterbore (i.e., rl - r2) such that the m~chine may readily
discrimin~te between the passing of adjacent coins. In other
words, there is no intercoin interference. Secondly, as
noted hereinabove, the present invention has achieved a coin
detection and validation arrangement in which the peak
value of signal variations and the width thereof are the only
signature signals necessary to completely discrimin~te
among coins in a typical set of coinage. Therefore, a
significant amount of asynchronism between the rotating
machinery and the occurrences of both the signal peak and
the positive and negative crossings of the reference voltage
may be easily tolerated.
To this end, it should be understood that the
above described timin~ devices disposed on drum 50 (not
shown) are arranged such that a "dark time" is provided
2s when one of counterbores 51 is physically centered under
air jets 66 of one of the output air valves. The time between
successive dark times for the timing apparatus is the time
required for a first counterbore to be centered under a
given coil and the time for the next adjacent counter bore to
become centered.
The timing apparatus of the preferred
embo~liment synchronizes with the dark time pulses and uses
these pulses which occur when the timing marks occlude
optocouplers, to ascertain the relative positions of
3s counterbores 50 with respect to both the rows 61 of air
30 l 334683
valves and sensing coils 70. Since the marks are arranged
such that the occlusion, and thus the dark time, occurs when
the holes 52 are centered under air pipes 66 (Fig. 3) the
apparatus will activate a~-o~liate ones of solenoid 65 at the
center of the dark times. When acquiring the data for the
signature signals, the apparatus reads data at a time which is
subst~nti~lly midway between the termination of the most
recent dark time and the onset of the next one. Naturally,
the onset of the next one is determined by locking on to the
0 pattern of tirning for the light and dark time as cylinder 50
rotates. In other words, the readings are taken at a point in
time when mid-points between adjacent counterbores are
centered under the sensing coils 70. This assures a condition
in which the response of the coil to the coin most recently
passed is stored, and can be read prior to the time the si~n~l~
in the coil begin responding to the approach of the next
adjacent coin.
Naturally, equivalent arrangements may be
constructed by reversing the significance of the light and
dark times and using electronic signals derived from devices
other than optocouplers in m~nners which will be f~mili~r
to those skilled in the art.
Turr~ing next to Figure S, a planer diagram of
the layout of sensing coils 70 and rows 61 of the solenoid
operated valves is shown. On the left hand side of the
drawing, row designations for the valves are shown as Rl
t~hrough R7. These correspond, respectively, to rows 61a
through 61g. On the left hand side, the direction of rotation
of the drum, relative to the array depicted in the drawing
figure, is shown by arrow 85.
Since, as described above, the length of the
rectangular geometries of coil 70 is significantly wider than
the diameter of the counterbores, in the preferred
embodiment a row of ten sensing coils cannot be physically
foImed due to spatial limit~tions. Therefore, the ten lead
31 l 334683
sensing coils 70a through 70j form a logically single row of
sensors, but are physically staggered such that each coil is
displaced from the two adjacent coils in the direction of
rotation by a distance equal to the intercounterbore distance
shown as 82 if Fig. 4A. Therefore, coils 70a, 70c.. through
70i are physically located on one row. Similarly, coils 70b,
70d...through 70j are physically located downstream from
the previous row and are displaced by one interbore
distance. Timing circuitry in the detection circuitry of the
preferred embodiment a~ropliately delays activation of
the valves based on the signals from the leading row,
cont~inin,~ coil 70a, by a period of time equal to one fortieth
of the time required for complete revolution of the drum so
that the output signals from, for example, coils 70a and 70b,
become logically and electrically synchronized within the
machine. In the preferred embodiment, drum 50 rotates at
approximately 16 revolutions per minute. Therefore, the
time required for adjacent center holes 52 to become
aligned under a given point exterior to the drum is
approximately 93 milliseconds. Those skilled in the art will
recognize that this is a relatively long time in the world of
modem microprocessors and that complete data acquisition
for a row of sensors, together with an apyro~riate analysis
to itlentify the coins, can be made within the 93 millisecond
2s interbore time period.
A correspondingly staggered set of lag coils
70a' through 70j' is shown at the opposite end of the array,
at the top of Fig. 5. The same physical constraints described
hereinbelow require the staggering of the lag coils.
However, as will be apparent from the description
hereinbelow, the lag coils need only be able to reliably
detect the presence or absence of any coin within an
embodiment of the present invention and thus simpler coil
geometries which would allow ten coils to be set side by side
32 l 3346~3
in single row may be used in constructing the lag sensors of
embodiments of the present invention.
In the preferred embodiment, air valve row
61a is disposed over the coin receiving station for dimes.
s Similarly, row 61b of the air valve is over the penny
receiving station, 61c over the station for nickels, and 61d
over the station for quarters. The selection of the stations is
arbitrary and any convenient selection of the relative
arrangement of the denominational significance of the
receiving station may be employed. Rows 61e and 61f,
corresponding to rows Rs and R6 are not normally used for
U.S. coins. However, of course, either of them may be used
for tokens in transit systems and the like which may be
present in coin input to be sorted.
It should be noted that the software controlling
the preferred embodiment assigns each of the chutes their
denominational significance and use. Therefore, any chute
may be assigned to receive any denomination under
software control without changing the mechanical
configuration of the m~chine. To this end, known statistics
about the contents of the input (or other criteria) may be
used to assign denominational significance to the chutes in a
manner which will lead to the most efficient sorting
procedure for the operation at hand. This may be done
2s statically or dynamically.
For example, if a load of coins is obtained from
pay telephones, it is likely that it will contain a large number
of quarters. The dynamic assignment of denomin~tional
significance allows the user to assign one particular coin
chute to quarters until a certain sum of money in quarters is
ejected through the chute. As soon as this event occurs, a
second chute is assigned to quarters and a message is
provided at the console alerting the attendant that the
predetermined amount of money in quarters is present at the
output of the first chute. The attendant may then take
l 334683
33
appropriate action, such as separate bagging of the output
from the first chute, while coin sorting continues with
quarters being ejected to the second chute.
This arrangement allows the present invention
s to be operated in a continuous sorting and counting process
rather than one which is limited to batch processes.
In the preferred embodiment, row R6,
corresponding to row 61f of the air valves, is disposed over
coin receiving station 56f which is used to received off sort
objects. As noted hereinabove, off sort objects are those
which are clearly detectable, but whose si~n~hlre signals are
so far out of range of any of the valid sets of signature
signals that they are treated as a bogus coin. Slugs, and
other stray metallic objects which may find their way to the
coin sorter will be rejected at this location. Off sorts are
treated by the software as any other denomination.
Therefore, any chute may be assigned to receive off sort
objects.
The last row 61g of the air valves is disposed
downstream, in the rotational sense, from the last coin
receiving station 56f. Therefore, any object blown out of a
counterbore at row R7 will be returned to the interior of the
rotating dlum. As noted hereinabove, the present invention
activates such valves when unknown objects are detected in
2s the counterbores. An unknown object is one which
generates sign~tllre signals close to those defined as valid for
a member of the valid coinage set, but are not within range.
It should be noted that this statement must be understood in
the context of the range of valid signature signals in the
present invention, i.e., that a range is defined for each of the
400 counterbore locations used in the preferred
embodiment. While these are naturally very close to each
other in value, they are not all identical for a given coin
denomin~tion. Coins which are marginal with respect to
content or size, due to age, v~n(1~lism, chemical abuse, or
-
34 l 334683
the like, may be detected as unknown objects by the
apparatus when passing sensing coil 70 in one counterbore,
but may fall within a valid range when traveling past a
different sensor in a different counterbore.
s Naturally, as unknown objects accumulate
within the m~chine, they will eventually be the only objects
left within the interior of the drum. The present invention
is constructed such that, if and when this condition is
encountered, the apparatus may be placed in a mode of
operation which all objects are ejected through a particular
one of the coin receiving stations and out a particular chute,
to finally clear the collten~s of the m~chine.
In the preferred embodiment, the lead sensors
are the primary detectors and are used as the primary coin
S validation and discrimin~tion devices. The la-g sensors are
used only to detect the presence of an object in a
counterbore after it has passed under the array of solenoid
operated valves. The preferred embodiment of the present
invention not only validates and sorts coins, but it counts the
number of coins output to each coin receiving station 56 and
thus the number of coins passed to each coin output conduit
58 (Fig. 3). Therefore, it is considered important to
confirm the ejection of a coin when the apparatus detects its
presence and denomination, and provides an appropriately
2s timed signal to the a~ ro~liate air valve in one of rows 61a
through 61d. If everything is operating properly, the coin
will be ejected into the coin receiving station and the lag
sensor on the channel for this coin will detect no coin at the
time this particular counterbore location passes under one
of the lag sensors 70'.
If the lag sensor detects no coin, it is assumed
(with great justification) that the coin was properly ejected
into the proper coin receiving station. Therefore, the count
for this particular denomination of coin is incremented
3s under these conditions. If the lag sensor detects a metallic
35 l 334683
object still present in this particular counterbore, the count
is not incremented. Those skilled in the art will quickly
appreciate that it is a matter of design choice whether to
increment the counter when the coin is detected and then
decrement same if the lag sensor detects that the coin is still
present or simply not to do the incrementing until proper
coin ejection is confirmed by the absence of a detected signal
at the lag sensor.
Additionally, the following should be
0 understood about the excitation sources employed in the
preferred embodiment. As will be described in greater
detail hereinbelow, the high frequency component of the
excitation signal is applied alternately to the staggered rows
of lead coils 70a through 70j in the preferred embodiment.
Therefore, the high frequency component will be applied to
excite coils 70a, 70c ... through 70i at times when the signal
is not being applied to coils 70b, 70d ... 70j. Alternately, the
latter set of coils will be excited by the high frequency signal
while the former set is not.
In the preferred embodiment, this switching
has a fifty percent duty cycle and is switched at a rate equal
to the frequency of the low frequency excitation signal.
The inventors of the present invention
discovered that this arrangement reduces cross taL~ between
2s the coils which might other~,vise result from the excitation
by the high frequency signals. Therefore, the distance
between two adjacent coils being excited by the high
frequency signal at any point in time is two ch~nnels, for
example, the space between coils 70b and 70d shown in Fig.
5.
Figure 6 is a section elevational view of one
end of the apparatus which shows cylindrical drum 50
rotating over coin receiving stations 56 and also illustrates
the positions of detector coil 70 and solenoid operated air
valve 65. It is believed that Figure 6 will assist in
36 1 334683
understanding the overall operation of the apparatus. Drum
50 rotates in the direction of arrow 53 shown in Figure 6.
The cross section of the rotating drum is taken through the
counterbores associated with channel 1. Therefore, these
counterbores pass under lead detecting coil 70a. Coil 70b of
one of the even numbered channels (channel 2) is also
visible in Figure 6 and illustrates the offset, in the sense of
the direction of rotation of the drum, among the lead
sensing coils for the odd and even numbered ch~nnels of the
preferred embodiment. Downstream from these coils, lag
coil 70a' is used to detect continued presence of a coin in one
of the counterbores of channel 1. Lag coil 70b' associated
with ch~nnel 2 is also visible in the drawing.
The partially evacuated plenum is shown at 54.
It creates a negative pressure tending to pull coins into
counterbores Sl until they are ejected in response to the
operation of one of solenoid operated air valves 65. For
purposes of Fig. 6, the plurality of solenoid operated valves
65 associated with channel 1, have been further denoted by
subscripts 1 through 7 indicating their position along the
direction of rotation.
Two exemplary coins are shown after they
have been ejected from counterbores 51a and 51d. It should
be understood that the drawing illustrates counterbore Sla in
2s its position when valve 657 is activated sending a jet of air
through pipe 667 ejecting the coin. The approximate
trajectory of a coin ejected from counterbore 51a is
illustrated by dashed arrow 64. The coin illustrated along
this line is for purposes of indicating the approximate
trajectory of a coin so ejected and not to indicate the coin's
position at the time it is ejected from counterbore 51a.
As shown in Figure 6, coins ejected in response
to operation of value 657 are unknown objects which are
returned to the interior of rotating drum 50. A second
3s exemplary trajectory is illustrated by dashed arrow 65
l 334683
37
showing that a coin ejected from counterbore 51d in
response to operation of air valve 654 will be deposited in
coin receiving station 56c. The inventors used a
combination of calculations and empirical tests to align the
s positions of air valve 65 with respect to particular ones of
coin receiving stations 56 into which such valves would eject
coins to take account of the tangential component of the
velocity imparted by the drum rotation and the radial
component of velocity imparted by the air exiting one of
lo nozzles 66.
Between the time a coin in a particular
counterbore location passes under lead coil 70a, and the
time it reaches the first of air valve 651, the signature
detection apparatus of the present invention acquires the
three signature signals used in the preferred embodiment,
compares same to stored calibration values, and makes an
appropriate decision as to which one of air valves 65 should
be operated to remove the coin from the counterbore. The
apparatus which acquires the signature signals and makes
this decision will now be described.
Figure 7 is a block diagram of the coin
detection and signature acquisition circuitry of the
preferred embodiment. The master controller for the
preferred embodiment is built around a type MC6809
2s microprocessor 110. As is known to those skillç~l in the art,
this microprocessor is a member of the 6800 family of
microprocessors currently manufactured by Motorola
Semiconductor Products, Inc. Details of bus signal timing,
register capacity, and other familiar parameters of
microprocessors for the MC6809 are well documented and
known to those skilled in the art. The processor employs a
16 bit address bus shown as 111 and an 8 bit data bus 112. A
multi-line control bus is shown as 115 is Figure 7.
The preferred embodiment of the present
3s invention uses memory mapped I/O to the signature
38 l 334683
detection apparatus. Therefore, the various digital signals
constituting signature signals are located at particular
logical addresses within the system memory. The decoding
and driving circuitry necessary to implement a memory
mapped data acquisition arrangement such as that of the
preferred embodiment is commonplace, and no further
details of same need be provided to understand the novel
aspects of the construction and operation of the preferred
embodiment.
lo In the preferred embodiment, system random
access memory is embodied by four type 6264 random
access memory chips shown as 117a through 117d. In the
preferred embodiment, memory chips 117 are battery
backed by conventional battery backup arrangements so that
they are functionally nonvolatile. This allows the valid
signature ranges obtained during the calibration process to
be saved during periods of time in which the machine is
turned off. As will be appreciated by those skilled in the art,
embodiments of the present invention may be constructed in
which saved calibration values are stored in other
nonvolatile memory devices such as magnetic disks. It is
well within the level of ordinary skill in the art to include a
disk drive connected to the system for storing constants
derived from a calibration process off-line for later use.
2s Bus circuits 111, 112, and 115 are shown as
le~lin~ to block 118 labeled port circuits. These represent
conventional computer ports, such as serial and parallel
ports, for connecting the input/output devices of CRT
display 41, keyboard 42 and printers 45 and 46, which are
pictorially shown at console 40 in Figure 1. The
construction of such circuits is conventional.
The inventors of the present invention have
recently constructed an alternate embodiment in which the
representative port circuits 118 have been replaced by a
3s single conventional serial port which is used to connect the
39 1 334683
apparatus of the preferred embodiment to a conventional
small personal computer, such as an IBM PC XT. This
allows a number of the maintenance, overhead, and report
generating functions which were previously written in
assembly language code and executed directly by
microprocessor 110 to be moved off line. A set of simple
instructions to the microprocessor to change operating
parameters in the machine and to otherwise control same
has been defined. Additionally, it allows the creation of a
simplified syntax for col--",l,-~ication between the controller
and the serial port and allows the user to use higher level
languages readily available for such small computers to
more easily perform some of the report generating and
ticket l~lilltillg functions.
Moving to the right hand side of Figure 7, a
block diagram of the architecture of the preferred
embodiment is shown. The address, data, and control buses
are each tied to 10 proximity/valve boards (PVB) 120a
through 120j, the first and last of which are illustrated on
Figure 7. Each of the PVBs is connected by a plurality of
conductors 121a through 121j, which include a LEAD
ENABLE signal provided through connector board 122
from oscillator board 125 on respective lines 126a through
126j. A group of 22 lines, shown collectively as 124,
carries signals from oscillator board 125 to connector board
122. The LEAD SIGNAL is provided on a respective one
of lines 127 from a respective one of lead sensors 70. A
LAG SIGNAL is provided on a respective one of lines 128
from respective ones of lag sensor 70a' through 70j'.
Lastly, a group of seven lines 129 connects the air valve
control outputs from each of the proximity/valve boards
120 to the seven air valves 65 associated with the channel
controlled by the respective PVB. Therefore, for each PVB
120, lines 126 through 128 are inputs to the board and the
3s seven air valve control lines 129 are the outputs.
40 l 334683
It should be noted that only signal lines are
illustrated on the controller and signature acquisition
circuitry drawings in this disclosure. Except where
otherwise noted, signal grounds, power supply conductors
s and the like are omitted for the sake of simplicity and
readability of the drawing figures.
The sensors and valves associated with each
channel, which are mounted on the surface of the drum as
illustrated in Figure 5, are shown as surrounded by dashed
lo lines 130a through 130j in Figure 7. Referring for a
moment to Figure 5, it should be appreciated that, for
example, the seven air valves 65 shown within block 130a
correspond to the left hand column of air valves associated
with channel 1, as illustrated in Figure 5. Thus, each group
1S of air valves controlled by one of the proximity/valve
boards is a column of valves shown in Figure 5, and
constitutes the seven air valves controlled for an individual
channel of the apparatus. Additionally, the groups 130 of
sensors and valves illustrate the electronic and
electromechanical components of the circuitry which are
secured to the drum, as opposed to being located on printed
circuit boards.
Before proceeding with a more detailed
explanation of the control and signature acquisition
2s circuitry, the relationship of the drawing figures will first
be described, so that the description may be understood in
context. As noted above, Figure 7 is a block diagram of the
entire system. There are ten individual proximity/valve
boards 120 and ten individual collections of sensors and
valves 130. There is a single connector board 122 and a
single oscillator board 125 for the entire system. Details of
the blocks shown in Figure 7 are illustrated in Figure 8
which consist of Figures 8A through 8E. First, Figure 8A
illustrates oscillator board 125. Figure 8B shows details of
3s connector board 122. Figure 8C is a diagram of each of the
l 334683
41
proximity/valve boards 120. The lead and lag signal
processing blocks of Figure 8C are illustrated in further
detail in Figs.8D and 8E, respectively.
With that in mind, the details of the other
s circuit elements of the preferred embodiment will be
shown. Turning next to Figure 8A, the master signal source
for the system is shown in the illustration of oscillator board
125. The basic source of excitation signals in the preferred
embodiment is 100 kiloHertz oscillator 131. It is important
in the operation of the preferred embodiment of the present
invention that oscillator 131 and the downstream circuits
carrying output signals therefrom exhibit good amplitude
stability. The output of oscillator 131 appears on line 132
which carries it as inputs to several other devices. First, a
zero crossing detector 135 provides a square wave output on
line 136 as the clock input to a counter chain 137 which
performs a divide by 64 function. This provides a square
wave output signal of approximately 1.56 kiloHertz on line
138.
First, the signal on line 138 is provided to the
control input of an analog switch 139, the signal input to
which is the 100 kiloHertz signal from line 132. This has
the effect of gating the 100 kiloHertz signal from line 132
on and off of line 140 at the 1.56 kiloHertz rate of the signal
2s on line 138. The signal on line 138 is inverted by inverter
141, the output of which appears on line 142 and is provided
to the control input of a second analog switch 145, the signal
input of which also carries the 100 kiloHertz signal from
line 132. The output from analog switch 145 appears on
line 146. It will therefore be understood that line 146
likewise carries bursts of the 100 kiloHertz signal, the bursts
being at the 1.56 kiloHertz rate. Due to the action of
inverter 141, the output on line 140 will pass the signal from
line 132 when the output on line 138 is held high. During
3s the opposite states of line 138, line 146 will carry the signal
42 - l 3 3 4 6 8 3
from line 132 and line 140 will be held low. The signals on
lines 138 and 140 are inputs to a mixer 146 and the inputs
from lines 142 and 146 are inputs to mixer 147. The
outputs of the respective mixers appear on lines 148 and 149
as the inputs to low pass filters 150 and 151, respectively.
The outputs from low pass filters 150 and 151 appear on
lines 152 and 153, respectively. Also, the asserted and
negated versions of the 1.56 kiloHertz signal on line 138 are
provided on lines 156 and 157, respectively.
From the foregoing, the following should be
appreciated. The outputs on line 152 and 153 each carry a
low pass filtered output of a mixed signal from the 100
kiloHertz oscillator 131 and the 1.56 kiloHertz signal output
from divider 137. While both of these signals are mixed
outputs of these two frequencies, it should be appreciated
that the 100 kiloHertz component is suppressed on line 152
when it is present on line 153, and vice versa. It should
further be appreciated that when the ENABLE (EVEN)
signal on line 156 is active, the 100 kiloHertz component
from oscillator 131 will be present on line 152. When the
ENABLE (EVEN) signal on line 156 is inactive, this signal
component will be absent from line 152. However, under
these ci~cu l~stances, the ENABLE (ODD) signal on line 157
will be active and 100 kiloHertz component will be present
2s on line 153. This is the source of the alternate excitation
(with a high frequency signal component) of the staggered
rows of lead sensors described hereinabove in connection
with Figure 5. The outputs on lines 152 and 153 are
provided, respectively, to five driver amplifiers shown as
158 and 159 in Fig. 8A. These provide ~lve lines carrying
identical even and odd excitation signals are shown
collectively as 160 and 161 in Fig. 8A. Amplifiers 158 and
159 are provided to give adequate drive and isolation to the
sensors.
- l 334683
43
The output from oscillator 131 on line 132 is
also provided to a low pass filter 163, the output of which is
provided to ten driver amplifiers shown as 162 in Fig. 8A.
The output from these drivers is provided on a collection of
ten lines 165 to give the LAG EXCITATION signal to each
of the ten lag sensing coils 70a' through 70j'. It will
therefore be appreciated that, in the preferred embodiment,
only the output from 100 kiloHertz oscillator 131 is used to
excite the lag coils, since their primary purpose is simply to
detect the presence or absence of a coin as each counterbore
passes a lag sensing coil.
Turning next to Figure 8B, details of connector
board 122 (Fig. 7) are shown. The lines entering the
drawing from the left hand side of Figure 8B are the signal
lines provided from oscillator board 125 illustrated in
Figure 8A. On the right hand side, collections of lines 121a
and 121b are shown for the proximity/valve board (Fig. 7)
120a and 120b for the first two ch~nnels.
The components on connector board 122 are
shown surrounded by dashed line 122 in Figure 8B. Note
that the connections for one fifth of the connector board are
shown. Therefore, the circuitry shown on Figure 8B will
be duplicated four additional times on the complete
connector board 122. The connections for the first two
2s channels are shown to illustrate the connection of exemplary
odd and even numbered channels to the signals from
oscillator board 125. Figure 8B is essentially self-
explanatory and will only be discussed briefly. First, the
ENABLE EVEN and ENABLE ODD signals on lines 156
and 157 from the oscillator board are connected directly
through the board to respective lines 121b and 121a for
channels 2 and 1, respectively. As shown on the drawing,
the enable signals from lines 156 and 157 are provided to
the other respective even and odd channels on the connector
board. An explanation of the connections for the odd
44 1 3 3 4 6 8 3
numbered channel 1 will be sufficient to explain the
operation of the other channels. One of the five lines from
group 161 (Fig. 8A) is provided directly to lead sensor 70a
mounted over the drum. The extension of the line from
s 161, and the two output lines exiting lead sensor 70a form
the group of three lines 167a illustrated in Figures 8B and 7.
A pair of these lines, shown as 168a, is provided as an input
to instrumentation amplifier 169a. As illustrated in Figure
8B, the instrumentation amplifiers 169 reside physically on
the connector board. In keeping with the notation adopted
elsewhere in this speci~lcation, refe~nce numerals followed
by letters a through j refer to like components for channels
1 through 10, respectively. Within such subsets, any
number which adds a prime (') to circuitry associated with
the sensors references an element associated with the lag
sensor for that channel.
The output from instrumentation amplifier
169a is provided on line 127a (part of group 121a) as the
LEAD SIGNAL signal line provided to proximity/valve
board 120a shown in Figure 7.
Similarly, the LAG EXCITATION signal
from group 165 is provided to lag sensor 70a', the output of
which is amplified by instrumentation amplifier 169a' and
provided on line 128a to the channel 1 PVB. The seven air
2s valve control lines 129a for channel 1 are connected,
through connector board 122, directly to the group of seven
lines 169a.
The connections for the even numbered
channels, including channel number 2 illustrated on Figure
8B, are identical except for the particular sensors and valves
associated with the particular channel to which the
connections are made, and the fact that the even enable and
excitation signals are used. Similarly, the connections
through connector board 122 for the rem~ining channels
3s are the same as those illustrated in Figure 8B.
. l 334683
Turning next to Figure 8C, a diagram of one of
the proximity/valve boards 120 is illustrated. Figure 8C
represents an exemplary PVB for one of the channels.
Therefore, the notation a through j indicating a particular
s channel has been omitted from the reference numerals on
Figure 8C. The signals for line group 121 are shown
entering the board at the left hand side. The connections to
buses 111, 112, and 115 are shown at the right hand side of
the diagram.
o The LEAD ENABLE signal on line 126 and
the LEAD SIGNAL output on line 127 from the associated
lead sensing coil are provided as inputs to lead signal
processing block 170. The LAG SIGNAL on line 128 is
provided as an input to lag signal processing block 171.
Details of the circuitry within these blocks are described
hereinbelow in connection with Figures 8D and 8E,
respectively. For purposes of discussing Figure 8C, the
following description of the outputs from signal processing
blocks 170 and 171 will suffice. Low and high frequency
peak signals appear as analog voltages on lines 175 and 176,
respectively. These are provided as two inputs to four
channel analog-to-digital converter 177. A lag output signal
is provided on line 178 to another input to A-to-D converter
177. Width enable signals for the lead sensors and lag
2s sensors appear on lines 179 and 180 from signal processing
blocks 170 and 171, respectively. Lastly, a clear signal is
provided as an input on line 181 to lead signal processing
block 170.
As will be explained in greater detail in
comlection with Figures 8D and 8E, low and high frequency
peak signals on lines 175 and 176 provide the signature
signals consisting of the peak of the amplitude of the low
frequency content from the LEAD SIGNAL on line 127 and
the high frequency signal content from the same lead. Thus,
3s the signals on lines 175 and 176 are low and high frequency
l 334683
46
peak amplitude signals forming part of the signature of the
coin passing the coil to which line 127 is connected.
The lead and lag width enable signals on lines
179 and 180 are the outputs of threshold detectors which go
high when the input signals on lines 127 and 126 are above a
threshold magnitude, after appropriate filtering and
rectification. The peak signals are converted to 8 bit digital
values by analog-to-digital converter 177 which are
provided to PVB 8 bit data bus 182 for reading by the
o system at a~pro~liate times.
The width enable signals on lines 179 and 180
are provided as inputs to the width measuring circuits
shown as surrounded by dashed lines 185. The width enable
signals on lines 179 and 180 are provided as one input to
each of respective NAND gates 186 and 187. The other
inputs to these gates are from width oscillator 188. The
outputs from NAND gates 186 and 187 are provided on
lines 189 and 190, respectively, to the clock inputs of lead
width counter 191 and lag width counter 192. It is apparent
from inspection of Figure 8C that the lead and lag width
enable signals on lines 179 and 180 alternately enable and
disable counting by counters 191 and 192, since they
alternately gate the clock signal from width oscillator 188
on and off. Thus, when the lead width enable signal on line
2s 179 goes high in response to a rising magnitude of the lead
signal on line 127, lead width counter 191 will begin
counting until a decline in the lead signal m~gnit~lde on line
127 reaches a point which causes the lead width enable
signal to go low. Therefore, the values stored in counter
191 will correspond to the time that the lead width enable
signal was high. As will be apparent from the explanation
of Figure 8D, this corresponds to the time during which the
magnitude of the high frequency component of the signal on
line 127 was above a predetermined value as an object
passed the particular one of lead sensor coils 70 to which
47 l 334683
line 127 is connected. Naturally, the count stored in counter
192 after it has been allowed to acquire a count represents
the width of the lag signal.
The 8 bit outputs from counters 191 and 192
appear on respective sets of eight lines 195 and 196 as inputs
to tristate buffers 197 and 198.
As noted hereinabove, the signature acquisition
circuitry for the proximity/valve boards 120, as shown in
Figure 8C, are all part of memory mapped VO address
space for the system memory. The signature components
include low and high frequency peak signals from the lead
sensing coil which are converted to 8 bit numbers by A-to-D
converter 177, and the leading width signal provided as a
count output on lines 195. Additionally, the lag detector
lS signature is provided only as a width signal in the form of an
8 bit number which appears on lines 196. All of the
signature values are applied, at a~L~ropliate times under the
control of microprocessor 110 (Fig. 7) to PVB data bus 182
for reading on to system data bus 112. Control logic block
210 is simply an implementation of well known address and
read request control logic for reading the data values of
particular logical addresses of system memory.
Implementation of circuitry to generate the functions of
control logic block 210 will be apparent to those skilled in
2s the art. A bus control signal appears on line 211 as a control
signal to bidirectional bus driver 212 which interfaces
system data bus 112 to PVB data bus 182. Four control
lines, shown as 215 in Figure 8C control analog-to-digital
converter 177. The clear output from block 210 appears on
line 181 and is provided to signal processing blocks 170 and
to the clear inputs of counters 191 and 192. Thus, when
processor 110 issues an instruction to write to the particular
address associated with the clear function, line 181 goes
high causing clearing of all the signature values stored in the
3s above referenced circuits.
l 334683
48
Separately decoded signals for reading the lead
width signature and the lag width signature are provided on
lines 216 and 217, respectively. These control the tristate
inputs to tristate buffers 197 and 198 connecting the outputs
from counters 191 and 192 to PVB data bus 182 at
appropriate times under the control of the microprocessor.
Naturally, when data is being read from the proximity/valve
board 120, line 211 controls bidirectional bus driver 212 to
transmit data from PVB bus 182 to system data bus 112.
lo From the foregoing, it should be clear that the
peak and width signature values are acquired by the
circuitry on the proximity/valve boards 120, as shown in
Figure 8C. These values are read on to system data bus 112
under the control of microprocessor 110 (Fig. 7). Analysis
of the signature signals takes place under the control of the
microprocessor, based on stored calibration values in
system memory. When this is accomplished, the
microprocessor writes signals back to each proximity/valve
board 120 to control the associated column of solenoid
operated air valves in a sequence which will be described in
greater detail in connection with Figures 10 and 11. Suffice
it to say that two decoded outputs from control logic block
210 are provided on lines 218 and 219 for l~tchin~ outputs
to the air valves for the ch~nnel controlled by exemplary
board 120 shown in Figure 8C, and for re~Aing the states of
those valves. When an 8 bit word (7 bits of which are used
to control the valves) is to be written to the valves, the word
a~ea s on system data bus 112 and is connected to PVB data
bus 182. A transition of the a~ropliate sense is then made
in the signal on line 218 to clock an 8 bit latch 220, thus
latching the valve control word into this device. The
outputs of the latch appear on eight lines shown as 221 and
are provided as the inputs to output driver 222, which
provides sufficient electrical drive to operate the solenoids
3s associated with the air valves.
l 334683
49
Additionally, information on the states of the
valves can be read by the system. The group of 7 air valve
control lines 129 is connected at point 225 to the outputs of
drivers 222 and to the inputs of level shifters 226. The level
s shifters convert the signal levels used to drive the solenoids
to ay~ro~liate logic levels which appear as outputs on lines
227. These are provided as inputs to tristate buffers 228.
When the microprocessor writes to the address associated
with control line 219, tristate buffers 228 are activated to
connect the output on lines 227 to PVB data bus 182 so that
information about the current states of the valves may be
read. This information is used to detect inoperative valves
and assure that proper outputs are being provided by the
system for a given state into which it is trying to place the
valves.
In s~lmm~ry, the data for the peak value and
width value signatures is all read on to system data bus 112
from the devices shown in Figs. 8C. Valve control words
are written from system data bus 112 into latch 220 to
control the 7 air valves associated with each particular
channel. Additionally, certain self-testing and calibration
information is provided by the preferred embodiment,
including the valve state re~din~ apparatus associated with
level shifters 226 and the lag signal output on line 178.
2s Figures 8D and 8E show details of ~e lead and
lag signal processing circuitry for blocks 170 and 171 of
Figure 8C. Turning first to Figure 8D, the elements shown
surrounded by dashed line 170 constitute the elements of the
lead signal processing circuit. The output from an
associated instrumentation amplifier 169 connected to the
lead sensor of the particular channel serviced by the PVB
appears on line 127. The lead enable signal appears on line
126 as the control input to an analog switch 230. It should
be recalled from the discussion of oscillator board 122 (Fig.
3s 8A) that line 126 is active when the lead sensor excitation
l 334683
signal contains bursts of the 100 kiloHertz higher frequency
signal of the preferred embodiment. Therefore, analog
switch 230 alternately passes signal from line 127 to point
231 in the signal path of the lead signal processing
s apparatus.
From point 231, the signal is processed for
high frequency content by the circuitry shown on the upper
portion of circuit 170 and for low frequency content by the
elements in the lower part of the figure. Proceeding first
o with the upper portion, the signal at point 231 is buffered by
an amplifier 232 and passes through a high pass filter 235
having a cutoff frequency of 52 kiloHertz. The output from
the high pass filter appears on line 236 where it is provided
as input to a 200 kiloHertz notch filter 237 which removes
any second harmonics of the 100 kiloHertz high frequency
excitation signal. The output from this filter is rectified by
full wave rectifier 238 and the output thereof is sent through
low pass filter 239 where it appears as an output on line 240.
From the foregoing, it will be appreciated that filter 235
attenuates any low frequency components in the signal from
point 231, and the combination of rectifier 238 and low pass
filter 239 provides a signal output on line 240 indicative of
the magnitude of the high frequency content of the signal
entering the processing apparatus on line 127.
2s The signal on line 240 is used to generate both
the peak signature signal and the width signature signal of
the preferred embodiment. The output on line 240 is
provided as an input to comparator 241, the other input of
which is connected to reference voltage source 242.
Reference voltage source 242 sets the trigger level for width
counter 191 (Fig. 8C) and thus serves to define a
predetermined threshold value for the definition of the
width of the pulse which will appear at point 240 in response
to a metallic object passing the lead sensor. The output from
3s comparator 241 appears on line 179 and controls the width
51 1 334683
counter as described hereinabove in connection with Figure
8C.
The signal from line 240 is also provided as the
input to a sllmming amplifier 245, the other input of which
is connected to negative reference voltage source 246.
Reference source 246 is selected to be negative in order to
expand the dynamic range of the output signal on line 247 to
take advantage of the full scale of analog-to-digital
converter 177 (Fig. 8C). The output on line 247 is provided
o to a conventional peak hold circuit 248 which acquires and
holds the peak value of the signal on line 247 and applies
same on line 176 as the HIGH FREQUENCY PEAK signal
provided to A-to-D converter 177.
The signal from point 231 is also provided on
lS line 249 as an input to a buffer amplifier 250, from which it
passes to a 2.6 kiloHertz low pass filter 251. The output
from this filter appears on line 252, and is rectified by a
second full wave rectifier 255 whose output appears on line
256. The signal from line 256 is provided as the input to a
second peak hold circuit 257 which retains the peak value of
the signal on line 256 on line 175, which provides same to
the analog-to-digital converter 177 (Fig. 8C).
Whenever control logic 210 (Fig. 8C) puts an
active clear signal on line 181, the outputs from peak hold
circuits 248 and 257 are reset to zero in preparation for the
OCCullellCe of the next pulse.
The lag signal processing circuit 171 is shown
in Figure 8E. It simply includes a 200 kiloHertz notch filter
258 which performs the same function as filter 237 in the
lead signal processing circuit. The output from this filter is
rectified by a full wave rectifier 259, the output of which is
low pass filtered by filter 260 to provide a signal at point
261. Keeping in mind that the lag coil connected amplifier
169' is excited only by the 100 kiloHertz signal from the
oscillator board, the signal on point 261 will be understood
s2 l 334683
to be a positive voltage indicative of the magnitude of the
detected signal from the lag sensor. During normal
operation, the signal from line 261 is provided as one input
to a comparator 262, the other input of which is connected
to reference voltage source 265. This combination serves
the same threshold setting function as comparator 241 and
reference source 242 serve in lead signal processing circuit
170. Thus, the output from the comparator which appears
on line 180 is used to control lag width signature counter
o 192 (Fig.8C) in the same manner.
The signal from point 261 is also provided to
line 178 as the lag output signal which in turn is provided to
A-to-D converter 177 (Fig. 8C). As discussed in connection
with Fig. 8C, this signal is used during calibration and
testing of the apparatus but is not, in the preferred
embodiment, used to generate a signature signal during
normal operation.
As noted hereinabove, and as will be apparent
from inspection of Figure 8D, only the peak value for the
low frequency channel of lead signal processing circuitry
170 is used in the preferred embodiment although width
values could also be used in connection with coinage systems
requiring a fourth signature signal to reliably discrimin~te
among members of the system.
Figure 9 represents typical peak and width
values for the high frequency channels for United States
quarters and dimes, respectively. The curve shown as 275
represents the output signal on line 240 in response to a
quarter passing one of the sensing coils. The curve labeled
276 represents the signal level on line 240 (Fig. 8D) in
response to the passage of a U.S. dime. The voltage level
indicated as Vref on Figure 9 represents the reference
voltage established by source 242 shown on Figure 8D. It
should be understood that the curves represented in Figure 9
are exemplary only and the actual curves generated by coins
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53
can vary widely in shape. Additionally, various additional
curves will be generated for other objects, such as tokens
and foreign coins, which the apparatus of the present
invention can reliably detect and identify.
Considering the case of the quarter for a
moment, it will be appreciated that a substantial voltage
output cuNe is provided in response to the passage of a
quarter under one of the sensors. The quarter signal crosses
the reference voltage at a time indicated at dashed line 277.
o It continues to rise until it reaches a peak voltage
represented as vpq on Figure 9. The signal then begins to
drop as the quarter moves on past the sensor until it falls
below the reference voltage at a time indicated by dashed
line 278 on Figure 9. Therefore, the time the signal is above
the reference voltage is the quarter width signal shown by
dimension line Wq on Figure 9 and this corresponds to the
count obtained by counter 191 (Fig. 8C).
The corresponding curve for the U.S. dime is
less sharp and has a lower peak value. Thus, the peak value
VPD is significantly lower. As a result, the period of time
during which the signal is above the reference voltage is
correspondingly lower and is represented by period WD
shown in drawing Figure 9. Again, this represents a count
obtained by counter 191 when enabled by the output of
2s NAND gate 186 (Fig. 8C).
Naturally, it will be understood by those skilled
in the art that processor 110 is kept rather busy. In the
preferred embodiment, the time between passage of
adjacent counterbore centers past a given point is on ~e
order of 93 milliseconds. The ch~nnel clear signals can all
be issued on line 181 subst~nti~lly simultaneously for all of
the channels since all PVBs decode the same signal as a
clear. Thus, once the peak and width values have been
cleared, the following should be apparent from the
3s foregoing description. First, both the peak and width
l 334683
54
detection apparatus operates asynchronously with respect to
the master timing source controlling microprocessor 110.
Thus, once the last acquired signal levels are cleared, the
next set of peak and width value signals will be
automatically acquired by the circuitry shown on Figures 7
and 8 without further- assistance by or attention from
microprocessor 110.
Data is read at subst~nti~lly the time at which
the center point between two adjacent counterbores on a
given channel is passing under the lead sensors. Due to the
speed at which microprocessor 110 can read data from its
data bus, the machine sequentially polls the ten ch~nnels, in a
short period of time, to acquire the signature signals from
the last row of ten counterbores passing the lead coils. Once
these are stored, it need only issue al.pro~liate clear signals
to reset the signature acquisition apparatus to its initial
conditions in preparation for the approach for the next row
of counterbores. In the meantime, microprocessor 110
compares the signature values obtained to the stored
calibrated values, and determines the denomin~ions of the
coins for each channel for the counterbore row which just
passed the sensors. When this is accomplished, a~plop~iate
output signals are provided into a memory queue to control
the operation of solenoid operated air valves 65 as the
particular counterbores just analyzed pass under the air
valve array. Once this is accomplished, the microprocessor
is ready to read the next set of 30 signature signals (three
from each ch~nnel) and proceed to process the data for the
next row of counterbores.
- Once the coin denomination has been
determined, it is appropriate to be able to output a signal
which will control ejection of the coins from the
counterbores in a m~nner such that the mic~oprocessor does
not need to concern itself further with the relative positions
of the coins as they pass over the coin receiving stations
l 334683
shown in Figures 3 and 6. However, it should be noted that
the sequence of coin denominations in adjacent counterbores
of the same channel is random. Since the coin receiving
stations are spaced apart by the distance between adjacent
s counterbores, but there is not preknowledge of the order in
which coins of particular denominations will appear, it is
quite apparent that it is possible for a coin which is
physically behind another, that is, in an upstream
counterbore with respect to the sense of rotation, to require
lo ejection before the downstream coin. In other words, coins
may be ejected "out of order" with respect to their
movement past a predetermined point on the sensor array.
To simplify the work of the microprocessor as
much as possible, the present inventors have created an
queuing system for controlling coin ejection by the air
valves. For each ch~nnel, a 7 bit word is defined in m~chine
memory which is manipulated logically to operate as seven
parallel shift registers. The coin ejection memory queue is
implemented by giving the m~chine access to one of 7 bits in
response to each coin detected. However, one and only one
particular bit of each of the 7 words may be set, depending
on the denomination of the coin detected.
To understand the operation of this, reference
is made to Figures 5,10, and llA through llE. Figure 10
shows the logical structure of the coin ejection memory
queue using four of the seven shift registers as an example.
Pive words labeled No through N4 are shown. At the top,
are the letters Q, N, P, and D which represent quarter,
nickel, penny, and dime, respectively. As the drum
physically rotates, the words are logically shifted in a
downward direction. Therefore, this memory queue
structure may be thought of as four parallel shift registers,
one for each coin denomin~tion. In the full 7 bit wide
memory queue of the preferred embodiment, two of the
3s rem~ining shift registers (not shown in Figure 10) are
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s6
devoted to the two other coin receiving stations 58 (Fig. 3)
and the last shift registers devoted to unknown values which
will be ejected back into the interior of the drum. During
conventional use, one of the shift registers associated with
s the coin receiving station will be used for off sort items.
The left hand bit of each word appears under the "Q"
column and thus this column represents a shift register
which controls the air valve which ejects coins into the
quarter coin receiving station. Turning to Figure 5 for a
moment, the right most bits shown in Figure 10 in the "Q
column" will always be used to activate, or fail to activate,
the air valve in this particular ch~nnel which appears on row
61d in Figure 5. Similarly, the next column proceeding to
the right is the nickel column and the bits in this column will
activate the air valve for this ch~nnel which appears on row
61c. In a similar manner, the "P" column bits control the
air valve on row 6 lb and the "D" column bits control the air
valve on row 61a.
The notation on Figure 10 indicates that all
valves are read as the output of word 0 each time a new set
of counterbores becomes centered over respective ones of
the coin receiving stations.
The diagonal set of letters, Q, N, P, and D
shown in words N4 through Nl represent the particular bit
which will be set in response to detection of coin
denomination. As noted on the left hand side of Figure 10,
once the coin denomin~tion has been determined by the
sensor, one and only one of these 4 bits will be set, assuming
that a valid coin of one of these four denominations is
detected. Therefore, if for any given counterbore, a
quarter is detected, a 1 will be placed in the left most bit of
word N4 where the letter "Q" appears in the drawing. If,
instead, a penny was detected, the second most significant bit
of word N2 would have been set and the rem~ining bits in
` l 334683
-
57
words N1 through N4 would remain unchanged (i.e., as
zeroes).
From inspection of Figure 10, it follows
logically that the sensing coil is, both physically and
s temporally, located one intercounterbore distance away
from the rank of dime ejecting air valves. In the preferred
embodiment, this will hold true for coils 70b, 70d
through 70j. However, it will be fully appreciated that the
queue can be constructed, will operate properly, for sensors
lo which are further upstream simply by increasing the
number of words between the Nl through N4 set which may
be manipulated by the microprocessor, and the word
corresponding to No at which all valves are read. Thus, one
extra word will appear in the queue between the nibble
which is read and the four Nl through N4 words for the
channels using sensor 70a, 70c ... 70i.
To understand the operation of this coin
ejection memory queue, a particular example will be used in
connection with Figs. llA through llE. The particular
example assurnes acquisition of data for a first counterbore
cont~ining a quarter, followed by a counterbore cont~ining
a penny. During this discussion, reference will be made to
Figure S to correlate the logical manipulation of the coin
ejection memory queue with physical movement of the
drum past the sensors and under the air valve array.
In Figs. llA through llE, X's in the memory
location represent don't know conditions which were set by
the microprocessor in response to previously detected coins.
This is to help focus the operation of the queue on the two
coins which form this example. The state of the memory
queue in Figure llA is shown at time Tl. A quarter has been
detected and therefore the left most bit of word N4 is set to l
and the other three bits on the diagonal of possible bits to be
set are left as zeros. Thus, in response to the detection of a
l 334683
58
quarter, the bit sequence 1000 is written on the diagonal
through the four words Nl through N4.
When the contents of the next counterbore has
been detected, all four logical shift registers of the coin
ejection queue have been shifted downward by one and the
microprocessor will set one of the diagonal bits in response
to the detection of the penny. As may be seen from
inspection of Fig. llB this gives the expected logical bit
pattern on the diagonal of 0010 corresponding to detection
lo of the penny. The previous 1000 diagonal has been shifted
downward one bit, and the four don't know conditions
which were at read word No at time Tl have been shifted
out. At time T2 the first bit from the example arrives at
read word No. This is the zero bit in the dime shift register.
This indicates that the dime solenoid will not be activated
for this channel at time T2-
Turning to Figure 5, and again assuming that
the present example is for sensor coil 70b spaced one
counterbore distance from dime air valve row 61a, it will be
appreciated that this is the proper system response. Since a
quarter was detected at time Tl, and it has moved one
counterbore position at time T2, this quarter is, at time T2,
located under the dime air valve on row 61a. Therefore, the
zero which appears in the right most bit of word No at time
2s T2 (Fig. llB) is al~ro~riate.
Another coin is read, the counterbores move
one position, and time T3 arrives. The state of the memory
queue at time T3 is shown in Fig. llC. Note, that another
diagonal bit set will be written at time T3 but is not shown in
the drawing figures, again to focus on the response of the
m~chine to the two coins of the example. At time T3, both
the penny and dime air valves are responding to zeros which
were placed in the queue as a part of the example. Again,
turning to Figure 5, it will be understood that this is
3s ap~ropriate by considering the sequence already described.
l 334~83
59
At time T3, the quarter will have advanced to row 61b and
will therefore be over the penny coin receiving station. The
penny, one counterbore behind, will have advanced over the
dime coin receiving station and will be under the valve on
s row 61a. Therefore, the two zeros which have resulted *om
detection of the two coins in the example give the correct
result.
Again, another shift takes place and the bit
pattern 001 now appears as the three left most bits of read
0 word No. It will be apparent that, whenever a 1 appears at a
given bit position in word No, a corresponding air valve is
to be activated. At time T4, the penny shift register is the
one which has the 1 at word No.
Once again returning to Figure 5, it will be
appreciated that, at time T4 the quarter has advanced to row
3 and is thus over the nickel coin receiving station.
Therefore, the zero in the nickel column of the coin ejection
memory queue lS a~ro~liate. However, the penny of the
example is one counterbore behind and is now over the
penny coin receiving station. Figure llD indicates that a 1 is
present in the read word for the penny shift register and, in
fact, the air valve from row 61b for this particular channel
will be activated ejecting the penny into the penny coin
receiving station.
2s Lastly, we come to one more shift of a
counterbore position at time T5, which is illustrated in
Figure 11 E. In Figure llE, a 1 appears in the read word
for the quarter column and indeed, between times T4 and
Ts, the quarter has advanced from its position over the
nickel coin receiving station to one over the quarter coin
receiving station. Therefore, the valve for this channel on
row 61d is activated and the quarter is ejected into the
a~yroyliate coin receiving station.
From the foregoing, it will be apparent that the
3s detected coin values are tr~n~l~ted into a diagonal bit pattern
l 334683
in the coin ejection memory queue in which one and only
one bit of the diagonal pattern is set in response to detection
of any given coin. It should further be noted from
inspection of Figs. llA through llE, physically, the quarter
s preceded the penny by one counterbore position. However,
since the penny coin receiving station is two counterbore
positions upstream from the quarter coin receiving station,
the penny was ejected first, at time T4.
From this it should be appreciated that, once a
lo coin value is determined for a given channel,
microprocessor 110 need only write the appropriate
diagonal bit pattern into the coin ejection memory queue
and it need concern itself no further with keeping track of
what coin is where, other than to implement the steps
necessary to perform the very simple shifting function
required to operate the queue.
As noted hereinabove, the present apparatus
lends itself quite readily to self-calibration. The apparatus
can be placed in a calibrating mode of operation under
control from the console 40 (Fig. 1). When in this mode of
operation, a representative sample of a collection of know
objects, for example, United States quarters or bus tokens
from a particular transit system, are loaded into the drum of
the preferred embo~liment. The apparatus is turned on and
2s proximity/valve boards acquire sets of the two peak and one
width signatures as described hereinabove in connection
with its sorting and counting mode of operation. Naturally,
if the coinage system at hand appears to acquire the use of
additional s~ re signals, same can be defined for such a
system in embodiments of the present invention.
During the calibration mode of operation, each
acquired signature value for each individual counterbore
location Sl within the drum is stored in memory 117 (Fig.
7). Each new acquired signature value for that particular
3s counterbore is compared to then current maximum and
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61
minimum stored values and, if greater than the maximurn or
less than the minimum, the new value replaces the old.
Furthermore, during the calibration mode of
operation, the solenoid operated air valves on row 61g (R7
in Figure S) are activated to return each of the objects to the
interior of the drum. This causes a random mixing of the
objects and will cause, at various times during the
calibration operation, the same object to be detected by
different ones of the sensing coil 70 in different particular
ones of the counterbore locations. In this way, an excellent
statistical sample of the response of a given machine
embodying the present invention to a representative sample
of known objects of particular type is obtained in data stored
for the valid set of signature signals. As noted hereinabove,
this can be stored in any form of nonvolatile memory
including off-line devices.
Naturally, when calibrating the system to
detect members of a particular coinage system, the machine
must be calibrated in the above described m~nner with
respect to each member of the set of the coinage system.
When this accomplished, a large number of variables within
the machine, which can vary significantly among different
counterbore locations sensing coils 70, but which
parameters do not vary significantly over time for a given
m~chine, are all accounted for during calibration.
It will further be apparent that the apparatus is
readily adaptable to changes in the coinage system that needs
to be handled by any operator. For example, if some form
of token needs to be detected, it need only be loaded in and
the m~chine calibrated for same. Naturally, various ones of
coin receiving stations 56 can be defined to receive those
coins during any subsequent operation by simple operations
at keyboard 42 (Fig. 1). Likewise, the machine is readily
adaptable, through the calibration process, to other changes
1 334683
62
in coinage, such as goveInmental changes in alloy content in
order to save minting costs.
The foregoing has been a full and complete
description of the preferred embodiment of the present
invention. From this description it will be appreciated that
the present invention overcomes the drawbacks of the prior
art noted hereinabove and also accomplishes the object of
the present invention previously recited. From the
foregoing description, many variations and equivalent
structures will suggest themselves to those skilled in the art
and therefore the scope of the present invention is to be
limited only by the claims below.
