Note: Descriptions are shown in the official language in which they were submitted.
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SP~-Cl~ICATION
Backqround of the Invention
Thls invention relates generally to new and
~l, oved means for p.oy. ~ng and operating coffee bean
grinders. More particularly it relates to such means whereby
the same grinder unit may be used to select and grind
different types of beans in accurate predete. ~ed quantities
ranging from a few ounces (e.g., 2 ounces) up to several
pounds (e.g., 3 pounds). Thus, when a grinder is equipped
with the novel p-oylamming and operating means of this
invention it may be used to serve one or more coffee brewers
of either the same or different types (e.g., multi-cup
quantity brewers or multi-gallon urn brewers).
In recent years it has become increasingly pop~
for restaurants and institutions to serve fresh brewed coffee
from "fresh-ground" coffee beans. This has created an
increasing ~q ~ ~ for coffee bean grinders having a high
degree of versatility 80 as to be readily adaptable to a
variety of different coffee,lmaking situations wherein not
only the quantity of beans to be ground but also the type of
coffee beans (e.g., "regular" beans and "de-cafe" beans) to
be ground must be ~c~ ted.
Coffee bean grinders are commercially available
which permit ready selection between two different types of
beans, and selection between fractional and full batch
quantities within a relatively narrow range of bean
quantitles. ~ ve~ these commercial grinders cannot
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accurately ~c~~ -date wide ranges in quantities such as
between a few ol~nces of ground coffee (e.g., 2 or more
ounces) and multi-pound quantities. Thus, the same grinder
was not adaptable to serve both coffee makers of the type
u~ed to brew coffee in multi-cup quantities (e.g., 5-10 cups)
and in g~llon quantities (e.g., 1-3 gallons). These prior
grinders utilized electro ochAn~cal timers which provided
adeguate accuracy over a relatively narrow range in the order
of several ounces (e.g., 2 to 5 ounces) but not over a wide
range in the order of several ounces up to several pounda.
From a number of st~ndrQ~nts it is desirable to
make available a basically "standard" coffee bean grinder
with sufficient ver~atility so as to meet the needs of a
small user such as a small restaurant or diner, or a large
user such as large combination restaurant and banquet hali.
Such a standard unit can be mass-produced, thereby reducing
the original cost as well as the cost of spare parts.
Furthe -_e, a standard unit tend~ to reduce the cost of
serviclng while increàsing the availability of experienced
service personne~
The grinding mech~n~s ~, motor drives and hopper
changing ech~n~sms in c_ o cially available coffee bean
grinders have adequate built-in versatility to meet existing
needs. However, the p.o~. jng and control components of
the commercially av~ hle grinders do not have adequate
versatility and flexibility. Hence, the object of the
invention, generally stated, is the provision of econ~. ~cally
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available coffee bean grinders which incorporate new and
i ,Loved p~OyL ing and cq~trol means which impart
substantially greater versatility 80 as to meet a wide
spect~ of user needs and reguirements.
More speciflcally, the ob~ect of the invention ls :~
to provide coffee bean grinders having a mic.Gp.ocessor
board, a 3-digit digital readout board and suitable switching
whereby the grinders will have one or more of the following
new and i _oved p-ogs- jng and control features:
1. In one operating mode have a grind cycle
deviation P~OYL? -hle in one-tenth second in~ ts from
0.4 second to 99.9 seconds, and in a second operating mode
have a grind cycle duration ~soy, --hle in seconds from 100
to 999 seconds;
2. Retain existing program settings in the event ;
of power loss due to outage or unplugging;
3. Have on-~ an~ recall of p~og~ settings by
use of a - - ~ device;
4. Have multiple settings for each bean hopper;
5. Be operable by actuating three switches; one
for hopper selection, one for grind cycle p.oys- ~ng and one
for initiating the grind cycle;
6. Be capable of coordinating the output of two or
more grinders from one coffee brewer;
7. Be psogs~ -ble by manipulating three switches,
one to turn on a readout display, one to scan the display
upward and one to scan the display downward;
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- 8. Provide automatic blanking of display LEDs
after a predetermined period of non-use.
S~mrAry of the Inv~ntion
The invention is directed, in combination with a
coffee bean grinder having a bean grinding mechanism, an
electric motor operably connected in driving relationship
with said grinding mechanism, dual bean hoppers mounted in
gravity feed relationship with said grinding mechanism, and
gate means interposed between said hoppers and said grinding
mechanism and operable to connect a selected one of said
hoppers in gravity feeding relationship with said grinding
mechanism, to grinder programming and control means
comprising a microprocessor and digital display means
operably interconnected with the microprocessor by circuit
means. The programming and control means include three
operator control switches, one functioning to condition the
gate means to place one of the hoppers in communication with
the grlnding mechanism, a second functioning to select a
grinding time, and a third functioning as a start switch.
In particular, the invention is directed in
combination with a coffee bean grinder having a bean grinding
mechanism, an electric motor operably connected in driving
relationship with said grinding mechanism, at least one bean
hopper mounted in gravity feed relationship with said
grinding mechanism, and gate means interposed between said
hopper and said grinding mechanism and operable to connect
said hopper in gravity feeding relationship with said
grinding mechanism, a coffee brewer operatively associated
with said grinder and including a control circuit providing
multiple brewing modes and providing a control effect on said
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grinder indicative of a selected brewing mode, said control
~ effect selecting a quantity of beans to be measured and
ground by said grinder based on a selected volume of coffee
to be brewed by said brewer. The grinder includes a
S programming and control circuit comprising a user-actuable
switch means for entering a user selected cycle time; a user-
actuable grinder activation means; a first digital storage
means for ~toring a first user-selected cycle time
appropriate for one brewing mode entered by said switch
means; a second digital storage means for storing an
alternate cycle time appropriate for another brewing mode
entered by said switch means; a hopper control circuit means
operable upon actuation of said activation means for opening
the gate means for a selected one of said stored cycle times;
a grinder motor control circuit means operable upon actuation
of said activation means for operating the grinder motor for
a grinder time cycle at least as long as said selected one of
said stored cycle times; and a selection circuit means for
selecting a desired brewing mode and rendering said hopper
and said grinder control circuit means responsive to said
first digital storage means when the associated coffee brewer
is in a first brewing mode, and responsive to said second
digital storage means when the associated coffee brewer is in
a second brewing mode.
Brief Descripti~n of the Dr~win~s
The features of the present invention which are
believed to be novel are set forth with particularity in the
appended claims. The invention, together with the further
objects and advantages thereof, may best be understood by
reference to the following description taken in conjunction
with the accompanying drawings, in the several figures of
which like reference numerals identify like elements, and in
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which: .
Figure 1 is a front, side and top perspective view
of a coffee grinder in which one embod~ ~t of the invention
is incoL~oLated;
Figure 2 is an enlarged perspective view of a
portion of the coffee grinder of Figure 1 with the timer
control panel access cover removed to show the timer set-up
panel thereof; "
Figure 3 is a s$mplified electrical schematic
diagram of the,coffee grinder;
Figure 4 is a simplified electrical schematic
diagram of the timer module of the coffee grinder;
Figures 5a and 5b are a simplifled logic flow chart
useful in underst~nd~ng the,,,operation of the timer module;
Figure 6 is a perspective view of a brewing system
comprising a grinder and a brewer incorporating a control
system constructed inlaccordance with the invention;
Figure 7 is a simplified electrical schematic
diagram of the brewing system shown in Figure 6.
Description of the Preferred Embodiment
Referring to the Figures, and particularly to
Figure 1, a dual-hopper grinder 10 is seen to include
generally a housing 11 within which a first hopper 12 and a
second hopper 13 are provided for receiving respective
quantities of two different types of coffee beans for
grinding. A solenoid-controlled shutter assembly (not shown)
allow beans to gravity feed from a selected onc of the
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hoppers to a motor-driven grinder (not shown) within
housing 11, which grinds beans from the selected hopper
following user-actuation of a grinder control switch 14.
The ground beans are collected in a brew funnel (not
shown) positioned on a base portion 15 of the housing.
Separate hinged covers 16 and 17 may be provided
for filling the hoppers, which each typically hold up to
six pounds of beans. A removable cover 18 may be
provided to facilitate access to the grinder mechanism
for cleaning or repair.
The construction and operation of grinder 10 are
described in U.S. Patent 4,607,200, entitled "Coffee
Maker", which issued to John D. Zimmerman on August 19,
1986, and is assigned to the same assignee as the present
application.
In accordance with the invention, grinder 10
includes a control system which enables the grinder to
grind precise quantities of coffee over a wide range of
grind cycle lengths. In particular, as shown in Figure
2, housing 11 includes a removable cover plate 20 which
provides access to a control panel 21. The control panel
includes a three digit display 22 of the grind cycle
duration, and a set of three push button controls 23, 24
and 25, which provide grind cycle increase, display and
decrease functions, respectively, when actuated. A pair
of machine screws 26 secure panel 20 over
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the di~pl~y and ~witcho~ durlng normal uso of the grinder.
~h- controls of panel 21 pro~id~ In con~unct~o~
w$th grlnd~r co~trol sw~tch 14 a cor~nlent ~nd pr~cise means
o~ controlllng grln~o~ operation. Dl~play window 22
~llumlnatea upon actu~tion Or any one or more o~ push-button
switche~ 23-25 to indicato t~ duratlon of the grlnd cycle.
For cycles les~ than g9.9 ~econd~, the last dlgit i~ a tenths
d~g~t. For cycle~ of 100 seconds or greater, time is
lnd~cated in ~c. ~q. ~he dl~pl~y stays ~lluminated ~o~ ~
~xed period of tlme following a control actuatlon, and then
~utomatically extlngu$~ho~ to prolong ln~cato~ llfe.
Re~orrlng to Figuro 3, withln grinder 10 push
button ~wltch-s 23-2~ ar~ connecLed t~rough a connector 26 to
a timer ~ c 30. Thl~ module pro~ides output 81~ A-D
at t~- ~amo so~ o~ whlch are con~orted to displAy control
~l~nal~ by a ~lsplay dr~ver 31. Ihe display control ~lgnal~
are app~led to throo seven-~egment dlsplay devices 32-34
which for~ th~ ~rlnd cycle durat~on di~play 22. In
~ccordance wlth conventional practlce, the applied control
~gnals an~ thc di~play devices ~re driven by strobe pulses
to ~C~U_4 w~rlng complexity. ~ransl~tors 36-38 and a
pu~ d~ven ~4quence counter 39 4equence the display
de~ico~. A t~analator 40 separately controls the decimal
po~nt Je; ~rt of dl-play devlce 33.
Addltional control lnputa ~re pro~lded to tim~r
v~ 1e 30 from the fou~ switch ~ect~ons 14a-14d of grinde~
control ~witch 14 through a second C~nneCtOr 41. When s~l~-ch
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14 is set for grinding beans in the left hopper, switch
section 14b applies an app-op-iate hopper selection signal to
the module. When the grinding cycle is initiated, switch
section 14d applies a start signal to the module. Similarly,
when the rlght hopper is selected switch section 14c provides
a hopper selection signal, and switch section 14d provides a
start signal as before. Switch segment 14a provides power to
grinder 10 only when one or the other of the hoppers is
selected. Selection of an alternate grind cycle for each
10 hopper is possible by momentarily actuating push-button
switch 42.
Timer module 30 provides output signals through a
- third connector 43 which actuates either solenoid 44 or
solenoid 45 to select the desired hopper. In addition, a'
15 control signal is provided to a relay 46, which controls the
application of AC line current to the grinder motor 47.
To set the grinder cycle the user removes cover
plate 20 and presses either increase or decrease push buttons
23 and 25 while observing the grind cycle duration in seconds
20 (or tenths of seconds) displayed on display 22. When the
correct duration is set, cover 20 is replaced and a brew
funnel is inserted under the grinder mechanism. Control
switch 14 is then rotated, counter-clockwise for the left
hopper, clockwise for the right hopper, momentarily into its
25 spring lo~ed start position, to initiate the grinding cycle
for the selected hopper. Once the grinding cycle has begun
the swltch is released from the start position and left in
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the run position pending completion of the cycle.
The output signals provided by module 30 first
actuate the app~op.iate one of solenoids 44 and 45 to select
the hopper, and then actuate relay 46 to operate grinder
S motor 47. The hopper ~ r - ~n-l open for the precise grind
cycle selected, after which~the selected hopper closes. The
grinder motor continues to be powered for a short
predete. ~ned period of time, typically in the order of 20
seconds, to clear be~n residue from the grinder. When the
grlnding cycle has been completed, switch 14 is returned to
its center off position.
The duration of the grinding cycle is set by the
- user to obtain a precise quantity of ground beans for a
reference brewing volume. In accordance with a further
aspect of the invention, where less than a full reference
quantity is to be brewed, timer module 30 may be conditioned
through a fourth connector 48 to provide a lesser ground bean
quantity. In particular, for 1/2 and 3t4 partial brews timer
module 30 automatically ad~usts the operating cycle of motor
47 to supply an app-op-iate quantity of ground beans to the
brewer. The quantity so supplied may be, but is not
necessarily, p.oyo~ional to the reduction in brew volume.
Referring to Figure 4, timer module 30 may comprise
a conventional microprocessor 50, such as the Intel 8051
series, ln ~ssori~tion with a latch 51 and an EPP~OM 52.
Control signals developed by switches 23-25 are buffered in a
conventional parallel-in serial-out data buffer 53 prior to
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application to microprocessor 50 Similarly, control signals
developed by grinder control switch 14 are buffered by a
conventional parallel-in serial-out data buffer 54
Control signals generated by microprocessor 50 for
the hopper selection solenoids 44 and 45 and the motor
control relay 46 are applied to conventional optical
isolators 55-58 through transistors 60-63 The outputs of
the optical isolators are connected to respective ones of
triacs 64-67, which control the application of AC line
current to the controlled ~ _,?nts
A reset circuit 68 is provided in timer module 30
to reset the microprocessor upon initial power-up of the
- grinder, and a beeper circuit 70 is provided to alert the
operator in the event of a malfunction A conventional power
supply 71 supplies operating power to the mi~,op,ocessor and
its asociated circuits
Referring to the simplified flow chart of Figures
5a and 5b, mic,op,ocessor 50 may be p.o~.ammed by
conventional techniques well known to those skilled in the
art to respond to increase and decrease operator inputs to
generate a reference counting state in a designated memory
location in a serial-in serial-out EEPROM 72 Then, upon
initiation of the grinder cycle, this count is transferred to
a counter within microprocessor 50 The selected hopper is
opened and the grinder motor runs as the counter is
de~ rted do ..~ ~dly by a clock circuit until its count
reaches a predet~ ine~ 'ni count, at which time the
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hopper is closed. The grinder motor is caused to continue to
run for a fixed period of time by further counting action.
By reason of the ability of miclopLocessor 50 to
accomplish designated algorithms, various timing factors may
S be lntro~uced in computing the grind cycle and actuating the
hopper selection solenoids and motor relay to compensate for
small or large brews, or when ~se~ -,dating a partial brew in
an associated brewer.
Referring to Figure 6, grinder 10 may be
advantageously operated in functional association with a
coffee brewer 80. Basically, brewer 80 includes a housing 81
which encloses a hot water reservoir (not shown), a brew
funnel 82 for receiving hot water from the reservoir, and a
container 83 for storing brewed coffee as the hot water
passes through funnel 82. A pour spout 84 may be provided
for dispensing coffee from reservoir 83.
To provide for convenient brewing of partial
volumes, e.g., 1/2, 3/4 of reservoir 83, brewer 80 includes,
in accordance with another aspect of the invention, a brew
volume select switch 85. So that a quantity of beans will be
ground by grinder 10 which corresponds to the brew volume
selected by switch 85, microprocessor 50 receives control
signals from switch 85 through a cable 86 which extends
between a connector 87 on the rear surface of the brewer
housing and a con~ector 88 on the rear surface of the grinder
housing. A second connector 89 (Figure 7) may be provided on
brewer 80 for co~nection to a second grinder.
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Basicilly, as shown in Figure 7, brewer 80 includes
a main resistance heating element 90 which is controlled by a
thermostat 91 and relay 92 to maintain water in the hot water
reservoir within a predete ined temperature range. A second
S ~llY~ ry resistance heater 93 and thermostat 94 may be
provlded to provide hot water. A predete, ~ned range of
water levels i8 malntained in the hot water reservoir by a
water level detector circuit 95, which opens a solenoid valve
96 to admit water to the reservoir when the water level falls
below the level of a sensing probe 97 in the reservoir. A
master switch 98 and indicator lamp 99 control and indicate
the application of AC line current to the brewer control
circuitry.
To brew coffee hot water is caused to flow from the
hot water reservoir through brew funnel 82 to coffee
reservoir 83. ~he duration of this flow, and hence the
volume of coffee brewed, is controlled by a brew timer
clrcuit 100. Inltlatlon of a brew cycle occurs with
momentary actuatlon of a switch 101, which may comprise a
spring-lo~ded position of on-off switch 98. Timer 100
responds by opening a solenoid valve 102 which allows gravity
flow from the hot water reservoir into the brew funnel.
To achieve partial brew quantities a first switch
section 85a of selector switch 85 conditions timer 100 to
open valve 102 for shorter time periods corresponding to
selected partlal brews. In accordance with the invention, a
second switch sectlon 85b simultaneously conditions the grind
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cycle of grinder 10 through connecting cable 86. A third
switch section 85c is provided in the event that it is
desired to also condition a second grinder (not shown).
Cable 86 is provi,~ed with three conductors 103-105.
When a full brew is selected by brew selector switch 85 none
of the conductors i6 connected. When a 1/2 brew ls selected,
conductors 104 and 105 are connected. When a 3/4 brew is
selected, conductors 103 and 105 are connected. The
particular connection results in selection by mi~Loplocessor
50 of an alternate q ~ location in EEPROM 72, and hence
termination of the grind cycle after a different
predete, ined time iffterval.
To set-up the grind cycles for the partial brew
selections it is only necessary to make the switch selection
on the brewer and then with access panel 20 removed, actuate
the increase and decrease switches 23 and 25 on panel 21
until the desired corresp~ndi ng grind cycle duratlon in
seconds i8 displayed on display 22. Thereafter, with
actuation of control ~witch 14 to a start position the
displayed grind cycle is accomplished. Switc~ ~4 may be ;~
actuated at any time to cause the grind cycle to be
displayed. The display is automatically extinguished after a
fixed period of time following the actuation of any one of
switches 23-25.
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Thus, the grinder and brewer operate as a system,
with the grinder automatically supplying a quantity of ground
coffee beans applo~,late to the brew volume selected by brew
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selector switch. Moreover, since the grind cycles are
independently se~ected for each brew selection, the quantity
of ground coffee beans for the partial brews need not be
directly ~lOpO~ Lional to the selected portion, but can be
ad~usted to provide a stronger or weaker coffee product as
desired.
While a particular ~ bo~ ?nt of the invention has
been shown and described, it will be obvious to those
skilled in the art that changes and modifications may be made
therein without departing from the invention in its broader
aspects, and, therefore, the aim ln the appended claims is to
cover all such changes and modifications as fall within the
true splrit and scope of the invention.
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