Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1~)42S30
BACKGROUND OF THR INVENTION
The present invention relates to a method and appar-
atus for automatically identifying a bottle which is transparent
to a laser beam cccording to the mold in which it was made. More
specifically, the invention relates to a method and apparatus for
automatically identifying and ejecting defectively formed bottles.
It is known in the art to automatically identify a
container, regardless of transparency, by a variety of surface
markings placed on the exterior of the container. Depending upon
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the purpose for which an apparatus has been designed, these sur-
face markings can indicate any of a number of events. For example,
it is known that in a machine which sorts a procession of metal
cans according to the contents of the cans, the contents can be
!
denoted by the application of non-reflective stripes on the ex-
terior of the can. More specifically, the precise location of a
non-reflective stripe connotes the nature of the contents of the
can. In such a sorting machine, a light source and detector
pair scans a limited area of the can exterior. All possible lo-
: cations for a stripe are scanned by a series of such source-de-
tector pairs. Accordingly, a multiplicity of light sources and
detectors is required in order to scan all possible stripe loca-
tions; The machine, then, requires a multiplicity of inspection
stations to identify each container. The identification of a
container by such a machine is unduly time-consuming and does
not lend itself for use with transparent bottles since the ex-
~`'! terior of such a bottle is non-reflective.
,~, Techniques and devices for automatically identifying
a transparent bottle are also known in the art. One such tech-
nique is to mark the exterior of the bottle according to the mold
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in which that bottle was formed and to mechanically count the
number of marks appearing on the bottle. For example, it i9 known
that to automatically identify the source of a glass bottle accord-
ing to the number of surface markings appearing on the bottle ex-
terior, a number of projections can be formed on the bottom of
the bottle. The number of projections, therefore, identifies the
source of the bottle. ~-
A procession of the bottles is fed through a plurality -
of inspection stations, each of which contains a set of mechanic- `-
~ally operated scanning switches which control an ejection channel.
Upon reaching the inspection sta tion, the bottle must be stopped `~ and the scanning switches brought into physical contact with the
bottom of the bottle. With the bottle stationary, the switches
i~ . -
rotatably contact the projections on the bottom of the bottle.
~ The switches, then, provide a count of the total number of pro- ~-
,3~1 jections. Since the number of projections corresponds to~a par-
ticular mold, the count serves to identify the source of the
,~ bottle. In the course of computing the number of projections,
the spatial distribution oi~ the projections is immaterial; the
swi~ches respond identically to all bottles having the same
number of projections regardless of the location and spacing
thereof.
A chief disadvantage of the prior art devices is the
necessity for stopping each bottle at the inspection station. A
considerable amount of time is wasted by interrupting the pro- ~ -
i~, cession to permit the inspection of each bottle. A furtber
j disadvantage of the apparatus is that the number of projections
which can appear on the bottle exterior is limited by the avail-
able surface area and the size of the projections. Accordingly,
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there is a practical limit to the number of projections which
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can be counted. As a result, a bottle can be identiifed with
respect to only a limited number of molds. Furthermore, since
the projections must extend considerably beyond the surface of
the bottom of the bottle to contact the scanning switches, the
projections themselves may introduce defects in the bottle
due to strain in the glass surface skin; and a projection may
fail to operate a switch due to bulge or sag in the bottom of
- the bottle, causing an erroneous count and a mistaken identifi-
cation.
A principal advanta ge of the present invention is to
optically inspect transparent bottles at a single inspection
station for identification with a preselected mold without inter-
rupting the flow of the bottles toward the packing station.
- BRIEF SUMMARY OF THE INVE~ITION
The present invention provides an apparatus for
identifying a bottle which is transparent to a laser beam and
which is provided with marks along a portion of its bottom wall,
comprising: means for conveying said bottle; means for directing ~ -
a laser beam through said portion of said bottom wall while said
bottle is moving; means for causing relatlve rotation between said
bottle and said laser beam while said conveying means moves said
~ bottle; means for detecting the presence or absence of spreading
'~! of said laser beam due to said marks; and means for generating an; electrical signal which identifies said bottle in response to
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said detecting means.
The present invention further provides a process for
identifying a bottle which is transparent to a laser beam and
. which is provided with marks along a portion of its bottom wall, ~`
comprising: directing a laser beam at said marks while rotating
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1~4ZS30
one of said beam and said bottle; passing said laser beam directly
through said portion of said bottom wall lacking said marks and
spreading said laser beam by said marks; and detecting the pres-
ence or absence of the spreading of said beam and generating an
electric signal identifying said bottle as a function thereof.
~ BRIEF DESCRIPTION OF THE DRAWINGS
.~
For the purpose of illustrating the invention, there
is shown in the drawings a form which is presently preferred; it : -
.. .. - . .
being understood, however, that this invention is not limited to -,
the precise arrangements and instrumentalities shown.
Figure 1 is a perspective view of the apparatus. ~ :'
Figure 2 is a bottom plan view of a horizontally mov-
able carriage and plunger.
Figure 3 is a side view of the horizontal plunger, the ~
sensor and the laser beam. ` ~ ; -
;:~ Figure 4 is a front view of the sensor in Figure 3
taken along line 4. .-
Figure 5 is a bottom plan view of the sensor in Fig-
ure 3 taken along line 5.
Figure 6 is a front view of a laser aperture plate. ~ ;
Figure 7 is a top plan view of a movable carriage and `
neck rollers.
Figure 8 is a bottom plan view of the bottle.
Figure 9 is a cross-section of a timing mark on the
bottle bottom.
Figure 10 i9 a block diagram of the electronic control
system.
Figure 11 is a chart of certain signals generated in
the electronic control system.
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DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, wherein like numerals in-
dicate like elements, there is shown in Figure 1 an apparatus for
identifying bottles which are transparent to a laser beam con-
structed in accordance with the principles of the present invention
and designated generally as 10. A main procession of bottles 12
. .
is shown being transported by a linear conveyor 14 of conven-
tional construction. The bottle 16 in the procession 12 are ~-
uniformly spaced apart by screw conveyor 17 and transported by
the inspection area by a linear conveyor 14 according to prin~
ciples known in the art.
As the bottle 16 enters the inspection area~ it is --~
engaged by a pair of spaced rollers 18 rotatably mounted on a
horizontally disposed plunger 20. As shown in Figure 2, the
plunger 20 is mounted for reciprocating movement to and f~om the
conveyor 14 on a horizontally movable carriage 22. The carriage
22 is mounted for reciprocation in a path parallel to the direc-
tion of movement of conveyor 14, designated by arrow A in Figure
1. At the beginning of the stroke of carriage 22 in the direc-
tion of arrow A, the plunger 20 is cammed or biased towards the
bottle 16. At the conclusion of the stroke, plunger 20 is cammed
or biased away from bottle 16, and carriage 22 then returns to
its initial position.
The carriage 22 moves in synchronism with screw con-
veyor 17 and linear conveyor 14. During the forward stroke of
carriage 22, rollers 18 engage bottle 16 without interrupting the
linear motion of bottle 16 in the direction of arrow A. The rol-
lers 18 press bottle 16 against a rotator belt known per se.
Preferably, the belt 24 moves in the same direction ae conveyor
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14. As a result, bottle 16 is caused to rotate about its axis as :
it traverses the inspection area. Rotator belt 24 may also move
in a direction opposite to that of conveyor 14 to cause bottle 16 -
to rotate but movement in the same direction as conveyor 14 is
preferred to facilitate the discharge of defective bottles that
have passed through the inspection area. The belt 24 is driven
by a variable speed motor so that the speed of rotation of bottle
16 may be adjusted as desired. It is preferred that belt 24
move at a speed sufficient to cause bottle 16 to rotate through
at least 360 as it traverses the inspection area.
'A second carriage 28 is positioned above conveyor 14
and is mounted for reciprocation in a horizontal direction paral- ;
lel to arrow A. See Figure 1. Specifically, carriages 22 and 28 ~ -
move in synchronism through the inspection area at a constant
;, .. . .
speed, and return to their inLtial positions at a substantially
sinusoidal rate after traversing the inspection area. A vertical
plunger 33 is mounted on carriage 28 for vertical reciprocating
movement to and from the neck of bottle 16. In particular, the
plunger 33 moves downwardly at the beginning of the inspection
area and upwardly at the end of the inspection area. Mechanisms
for synchronizing the reciprocating motion of carriages 22 and
28 and for moving the plunger 33 are known in the art and do not
per se form the present invention.
As shown in Figure 1, a pair of spaced neck rollers
58 is rotatably supported by plunger 33. Neck rollers 58 hold
bottle 16 downwardly against any vertical forces generated by ro-
tation of the bottle 16. The neck rollers 58 are positioned to
contact the neck of bottle 16 when rollers 18 press bottle 16
against rotator belt 24. It is preferred that neck rollers 58 ~ -
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be made from a rubber or plastic material to prevent damage to
the neck of bottle 16 upon contact therewith.
A ring 50 is mounted on carriage 28 and depends there-
from. The ring 50 may be two semi-circular segments at the same
or different elevations.
A laser 26 is mounted on second carriage 28 so that
the position of a laser 26 with respect to carriage 28 is adjust- -
able. In addition, a mirror 32 is mounted on the carriage 28
and is positioned to direct the laser beam, indicated by the broken
line B in Figure 1, through the opening in the neck of bottle 16
.
and to the bottom wall 34 thereof as bottle 16 moves through the ~5.
inspection area. See Figure 3. A sensor 35 is securely mounted
on carriage 22 and is positioned to detect the laser beam as it
emerges from bottom wall 34 of bottle 16. The laser beam is di-
rected by mirror 32 shown in Figure 1, to the annular sectors
66 of bottom wall 34 as shown in Figure 5 and 8.
The annular sectors 66 are provided with marks 68
which disperse the laser beam emerging from bottom wall 34 as
described more particularly hereinafter. As show~ in Figures 1
and 3, a mirror 40 is securely mounted on a stationary support
member 42 positioned alongside conveyor 14. The mirror 40 is
sufficiently long to intercept the laser beam and direct it to
sensor 35 over the length of the inspection area. Thus, as
carriages 22 and 28 move in synchronism with bottle 16 through the -
inspection area, the laser beam is directed through the bottom
wall 34 of bottle 16 and reflectet by mirror 40 to sensor 35.
Referring to Figure 2, plunger 20 is guided for re-
ciprocating movement by a sleeve 30 and guide rollers 46 rotatably
mounted thereon. Springs 44 bias plunger 20 towards conveyor 14
as the carriage 22 traverses the inspection area in the direction
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of arrow A. A yoke bearing plate 48 is securely mounted on
carriage 22 and is reciprocated in a direction toward and away
from conveyor 14 by a crank roller 50 shown in Figure 3 as a
dotted circle. The lateral reciprocating movement of plate 48
is generated by means of two mechanisms, one horizontal and one
vertical, which are well-known in the art.
Plunger 20, at its distal end with respect to con-
veyor 14, is fixed to a head plate 45. The head plate 45 is con-
nected by springs 44 to a support member 52 on carriage 22.
Springs 44 provide a biasing force which urges the head plate 45
against the sleeve 30 and therefore biases the plunger 20 toward
conveyor 14. However, when rollers 18 first contact the bottle
16 as it enters the inspection area, the bottle pushes the plunger
20 away from conveyor 14 and the springs 44 expand to accommodate
motion of the head plate 45 away from sleeve 30. .
., .
The reciprocating motion of plunger 20 toward and ~
`. away from a bottle 16 is generated by crank roller 50 which ~ .
0 drives yoke bearing plate 48. Sleeve 30 is fixed to bearing plate
;i 48 and, at its distal end with respect to conveyor 14, abuts the :
kead plate 45 which is fixed to plunger 20. As sleeve 30 is -~
`~. moved to the right in Figure 2 by crank roller 50 and bearing
. plate 48, the head plate 45 follows sleeve 30 due to contraction
i~ of the springs 44. Since plunger 20 is coupled to head plate
. : 45, it too is urged towards conveyor 14 so that rollers 18 may
.
; engage bottle 16. When sleeve 30 is moved in a direction away
. . .
. from conveyor 14, (from right to left in Figure 2), sleeve 30
urges head plate 45 and plunger 20 in the same direction.
Accordingly, rollers 18 lose contact with bottle 16.
.
The reciprocating motion of plunger 20 toward and -
away from conveyor 14 is synchronized with the motion of carriage
22. Carriage 22 moves reciprocatingly, parallel to conveyor 14
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11~)42530
over the length of the inspection area. The reciprocating motion
of carriage 22 is generated by cam follower 54 mounted thereon
which cooperates with an annular cam track (not shown). A trans-
verse member 56, securely mounted on carriage 22, rides between
a plurality of rollers (not shown) to guide carriage 22 along a
path parallel to conveyor 14 as carriage 22 reciprocates in re- -
sponse to a camming action on cam follower 54. Therefore, at
the beginning of the stroke of carriage 22 in the direction of
arrow A, sleeve 30 is cammed towards conveyor 14 and springs 44
urge plunger 20 towards bottle 16 as it enters the inspection
area and embrace bottle 16 as it i9 inspected. At the end of the
stroke of carriage 22, sleeve 30 is cammed away from conveyor 14,
pushing head plate 45 and plunger 20 away from bottle 16. Rollers
20 release bottle 16 and carriage 22 returns to its initial posi- - :
tion so that the process may be repeated with the next bottle 16.
All of the above is accomplished without interrupting the continu- -
ous motion of each bottle 16 through the inspection area.
Referring to Figures 1 and 6, a pair of laser aperture
... .
plates 60 and 61 are mounted on ring 50 on carriage 28 and are
` positioned in the path of the laser beam. As shown in detail
.. . .
~i in Figure 6, the aperture plates 60 and 61 are provided with ~ -
:
rows of apertures 62 and 63, respectively. The apertures 62 of
~'~ plate 60 are aligned with the apertures 63 of plate 61 and laser
.~ 26 is positioned so that the laser beam passes through one pair -
~; .
of the aligned apertures 62 and 63. Mirror 32 is then fastened
~; to aperture plate 61 and is positioned to reflect the laser beam
so that the reflected beam lies in a vertical plane perpendicular
to conveyor 14 and strikes the annular sectors 66 of bottom 34,
` as shown in Figures 3 and 8. Mirror 32 is positioned to reflect
. the laser beam 90 that it passes between the neck rollers 58 and
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through the opening in the neck of bottle 16, as shown in Figures
1 and 3. Thus, the beam travels freely, not striking any part of
bottle 16, until it impinges on an annular sector 66 of bottom wall
34.
Referring now to Figure 8, there is shown in detail
the feature of a bottom wall 34 of bottle 16 which is used in the
present invention. Specifically, in the preferred embodiment
shown, a plurality of marks 68 are distributed in the annular
sectors 66 to provide an optical signal which represents a binary ~ -
number. However, it shuuld be understood that for purposes of
the invention the mark 68 could also be distributed circumferen-
tially about the side walls of the bottle 16, the positioning of
the sensor 35 and mirrors 32 and 40 being modified accordingly. ~
The binary number identifies the mold in which the bottle 16 was ~ -
formed. As shown, two annular sectors denoted S and T, (the "tim-
ing sectors") are diametrically opposed and are provided with a
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;' plurality of marks 68. Timing sectors S and T serve to initiate
or terminate, xespectively, the detection process described
hereinafter.
On either side of the diameter connecting timing
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sectors S and T, there are shown an equal number of annular sectors
66 each of which are provided with no more than one timing mark
58. Annular sectors 66 above the diameter connecting sectors S - -
and T are denoted as 100, 200, 300, 400, 500 and 600; and the
annular sectors 66 below are denoted as 700, 800, 900, 1000, 1100
.,~ .
and 1200. The marks 68 are arranged so that pairs of sectors 66 ~ -
are marked identically. Thus, sectors 100 and 700 are marked
q~ identically and so are sectors 200 and 800; 300 and 900; 400 and
1000; 500 and 1100; and 600 and 1200. The absence of a timing
mark 68 in a sector 66 connotes a binary "0" while the presence -
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1~4ZS30
of a mark 68 connotes a binary "1". Traversing the annular sec- -
tors 66 in a clockwise direction, annular sectors 100, 200, 300,
400, 500 and 600 define the binary number "011000", as do sectors
700, 800, 900, 1000, 1100 and 1200. By changing the distribu-
tion of the timing marks 68, a multiplicity of binary numbers
is defined. For example, in Figure 8, sixty-four binary numbers
may be defined using six annular sectors 66. This is shown below
in Table 1 where each annular sector 100, 200, 300, 400, 500, .-:.
and 600 has been assigned a unique position in a six digit binary
number.
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o
o o o o ~ ~ ~ ~ ,
t~ h O
~ O o ~oooooooo,~,l~,
~ C~ o
¢ U~ o ~ o O O O ~ ~ 0 0 0 0 ~~
o
o o~oo~,loo,l~oo~oo~
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o ,lo~o~o~o~o,~o~o~o_~o~ ,: '
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. ~ o o o o o O O
O _I~I~lr-l_l~_1~10000000000000 ,",~,
o
.~, Z ~ o o~ 1~00000000~
o ~oooo~,l~,loooo~ ~0000~1 -
mo
o _~oo~oo~oo_I_100~00~_10
. ~ C~
~ _I o ~lo~o,lo~o~o_10~10,~0~0,10,~0 \ ~ ~:
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~0 ooooooooooOoOOOOOOOOOO , ~ ' '
o/ F~O 000000000000000.-1~1~1~--1~1~1
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g 0000000~1~1~1~,~0000ooo
o
Cl o ooo~,~ oooo,l,~ oooo,
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~ o o_~oo~,loo,~,loo~,loo~,loo~
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'.,, o ~lo,lo~lo~o~lo,lo~lo,~o,lo~o~o '-
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Each binary number has a decimal equivalent as shown in Table 1
Assuming tha t the binary number "000000" (decimal 0) is not used,
there are sixty-three arrangements for the marks 68. Accordingly,
any bottle 16 may be identified with any one of sixty-three dif- -
ferent molds, each of the sixty-three possible arrangements of
marks 68 on any bottle 16 being formed by an associated mold. The
number of marks 68, of itself, does not identify a bottle 16 with
a particular mold. Instead, the distribution of the marks 68 on -~
the bottom 34 of bottle 16 determines the identity of the mold in
which bottle 16 was made. For example, as shown in Table 1
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above, a single mark 68 may be placed in any of the six annular
sectors 100, 200, 300, 400, S00 and 600 to produce six different ~
binary numbers (decimal equivalents 1, 2, 4, 8, 16, 32). If the :
number of timing marks 68 were merely counted, an erroneous iden-
tification would result. The method of the present invention -~
permits the identification of a bottle with a siginficantly -~
greater number of molds, avoiding the need for a multiplicity `-
of machines in a plant which employs large numbers of molds.
1~ In the preferred embodiment shown in Figure 8, the
s~ marks 68 are distributed among the sectors 66 above and below the
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diameter connecting sectors S and T so that each group of sectors
66 above and below said diameter defines the same binary number
when traversed in like directions. Thus, either timing sector
S or T initiates the detection process and regardless of which
timing sector, S or T, initiates the detection process the binary
number detected will be the same due to the paired distribution
of the marks 68 (previously dlscussed).
Referring now to Figures 3 and 5, the preclse manner
in which the marks 68 produce the desired optical effect will be
described. In Fi~ure 5, bottle 16 is shown being transported
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through the inspection area on conveyor 14. As previously men-
tioned, the rollers 18 engage the bottle 16 and urge it against
rotator belt 24 causing bottle 16 to rotate as it traverses the
inspection area. The rotator belt 24 is positioned so that the
bottom 34 of bottle 16 overhangs the edge of conveyor 14 closest
to sensor 35. More specifically, the annular sectors 66 of bottom ~
34 are exposed beyond the edge of conveyor 14 as bottle 16 rotates. -
The laser beam passes through the opening in the neck of bottle 16
and strikes each annular sector 66 as it is exposed beyond the edge
of conveyor 14. The beam passes through sector 66 and strikes
mirror 40 which directs the beam to sensor 35. Sensor 35 includes
a sensor mask 70 and two photocells 72 and 73. Depending on the
beamwidth of the laser beam reflected from mirror 40, the sensor
35 generates a digital output signal corresponding to either a :
binary "O" or "1".
If the laser beam strikes an annular sector 66~ which
contains no mark 68 the beam will pass through sector 66, strike
mirror 40 and travel on to sensor mask 70 shown in Figure 4.
The mask 70 blocks the beam, represented by arrows E in Figure 5,
from striking the pair of photocells 72 and 73. Therefore, the
photocells 72 and 73 do not receive the la~ser beam when sector
. , .
66 has no mark 68 located therein, and they generate a digital
signal representing a binary "O". On the other hand, if sector
66 is provided with a mark 68 the laser beam will strike mark 68
and fan out as shown by arrows C and D in Figure 5. The physical
dimensions of mark 68 are such that the width of the laser beam ~
emerging from mark 68 is greater than the width of the mask 70, -`
at sensor 35. As a result, photocells 72 and 73 will detect the
beam. The speed with shich bottle 16 rotates with respect to the
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laser beam is controlled by rotator belt 24 and i9 set so that
every annular sector 66 on a semi-circle between timing sectors
S and T will be presented to the laser beam as bottle 16 is rotated
and transported through the inspection area. Therefore, the
speed of rotator belt 24 is set so that the bottle 16 rotates at
least 360 as it is transported through the inspection area. Those
sectors 66 having marks 68 will cause photocells 72 and 73 to
generate a digital signal which indicates the presence of the mark
.. ..
68 by a binary "l". But if sector 66 has no mark 68 therein,
photocells 72 and 73 will not receive the laser beam and they will
generate a digital signal which indicates the absence of mark 68
~ by a binary "0".
'~As mentioned previously, carriage 28 moves in synchron- -
ism with carriage 22 and bottle 16 as bottle 16 traverses the in- -
spection area. Since mirror 32 is securely mounted on carriage
28 and sensor 35 is securely mounted on carriage 22, mirror 32
and sensor 35 move in synchronism with each other and with bottle
16 as it is rotated and transported through the inspection area.
Accordingly, the binary number characterized by the marks 68 in
a semi-circLe between timing sectors S and T will be detected
by sensor 35.
In the preferred embodiment shown in Figure 9, mark
1 ~:
' 68 is in the shape of a prism projecting outwardly from the under-
side of bottom wall 34 of bottle 16. However, mark 68 may take
i -
any shape so longas it causes the laser beam to spread in the man-
ner previously described~ For example, mark 68 may also be a
;l depression in bottom wall 34, and shaped as a prism.
~j~An electrical control circuit shown in Figure 10, and
. designated generally as 80, responds to the electric signals gen-
erated by photocells 72 and 73. The timing sectors S and T initi-
ate and terminate the detec~ion process with respect to a particu-
`~lar bottle 16 according to a form of pulse width discrimination
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described herein. As mentioned previously and as shown in Figure 8,
timing sectors S and T are provided with a greater number of marks
68 than the other annular sectors 66. In timing sectors S and
T, the marks 68 are spaced so that the laser beam is continuously
received by the photocells 72 and 73 over the time period required
to rotate the bottle 16 through the arcuate distance spanned by
sector S or T. Photocells 72 and 73, then, will generate an ~-
electric signal corresponding to timing sector S or T which has - -: -
a pulse width greater than the pulse width of an electric signal ~
generated in response to any other sector 66 having only a single -
mark 68. ~: .
The electric control circuit 80 discriminates between
the pulse widths of the electric signals generated by photocells
72 and 73. The circuit 80 does not begin the detection process
until either timing sector S or T causes a relatively long pulse
, to appear at the output of photocells 72 and 73. And once begun,
the detection process does not terminate until ph otocells 72 and :~ .
73 receive a second pulse of relatively long duration. For ex-
ample, if timing sector S produces the first relatively long
pulse to begin the detectionprocess, then the detection process
, will not terminate until timing sector T produces the next such
pulse. In the interim, photocells 72 and 73 will detect the :~
binary number represented by the arrangement of marks 68 in a
:r' semi-circle of sectors 66 located between timing sectors S and . ;
' - T. Although, in Figure 8, timing sectors S and T are each shown ~ ~:
, to have four marks 68 therein while any other sector 66 has at
. most one mark 68, it should be appreciated that the desired
pulse width discrimination can also be achieved using ather
numbers of marks 68 in each eector 66. For example, timing
, sectors S and T each may be provided with six marks 68 while :
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any other sector 66 has at most two marks 68. The precise
numbers used will depend essentially on the pulse-width dis-
crimination capability of the electronic components used in
circuit 80.
Referring to Figures 8, 10 and 11, assume that timing
sector S produces the first pulse of relatively long duration
(the "long pulse") which initiates the detection process. Thus,
as bottle 16 rotates in a counter-clockwise direction, a series
of pips will appear on lines 99 and 125 as shown in Figure 11.
With three marks 68 in timing sector S, three pips, designated
as 151 in Figure 11, will serve to initiate the detection process ~-
as described further hereinafter.
The three pips 151 are shaped by Pulse Shaping Net-
work 81 or 82 to produce the long pulse on lines 83 or 84. In
Figure 11, the long pulse generated by sector S is designated as
152. Long pulse 152 gates OR gate 85 which produces a digital sig-
nal on line 86 corresponding to the pulse waveform on liens 83 or ;
84. The leading edge of the digital signal on line 86 triggers -
a One Shot Multivibrator 87 which produces an output pulse (the
"one shot pulse") on line 88 in response thereto. The digital - -
output of Multivibrator 87 on line 88 is fed to AND gate 89 in
conjunction with the digital output of OR gate 85 on line 86. The
digital output of AND gate 89 on line 90 is a pulse designated
as 153 in Figure 10. Due to the signals on lines 86 and 88,
pulse 153 has a pulse-width which equals the pulse-width of
152 lessthe pulse-width of the one shot pulse.
The trailing edge of pulse 153 triggers Two Bit Counter
91 which controls AND gate 94. As well known in the art, each
cell in Counter 91 has a regular output and a complementary out-
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will be at a "l", and vice-versa. As shown in Figure 10, the first
cell has a regular output Ql- and the second cell a complementary
output Q2 Initially, Counter 91 is set at zero by a reset switch
which may be any suitable switch known in the art. The regular
outputs of both cells in Counter 91 will therefore be at "0".
When the first pulse 153 on line 90 is fed to Counter 91, the
first cell in Counter 91 registers "1" at terminal Ql and line
92. At the same time, the second cell in Counter 91 re~ains in
its initial state, that is, at a "0". The complementary output ~;
of the second cell, however, will indicate a "1" at complementary
terminal Q2 and line 93. Accordingly, the output of AND gate
94 on line 95 will rise to a "1" level in response to the "1" -
levels on lines 92 and 93. The output of AND gate 95 will gate
Astable Multivibrator 96. More particularly, Multivibrator 96
will be gated on by the leading edge of the signal appearing on -~
line 95.
When gated on, Astable Multivibrator 96 generates
a series of clock pulses on line 97. The clock pulses appearing -~
on line 97, in conjunction with the digital signal on line 86,
controls AND gate 101 which sets Flip-Flop 102. More specific-
ally, the output line 115 of AND gate 101 is connected to the Set -
Input of Flip-Flop 102. When the signals on lines 97 and 86 are
both at the "1" level a pulse will be generated at line 115, as
shown in Figure 11. In response, Flip-Flop 102 will be set and
line 114 will rise to a "1" level. The signal on line 114, how-
ever, will return to the "0" level when ~lip-Flop 102 is reset.
As shown in Figure 11, Flip-Flop 102 is reset at the trailing
edge of a clock pulse on line 97. Actually, as shown in Figure
10, the clock pulses on line 97 are inverted by Inverter 98 and
fed, through RC circuit 116, to the Reset Input of Flip-Flop 102.
Thus, the leading edge of the inverted clock pulse, which coin-
cides with the trailing edge of the original clock pulse on line
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97, re~;ets Flip-Flop 102~ RC circuit 116 is a simple holding
circuit, well-known in the art, which holds the inverted clock
pulses at the digital "0" and "1" levels~
Each pip, designated as 154 in Figure 11, appearing
on lines 99 or 125 due to a single mark 68 in a sector 66 is shaped
by Pulse Shaping Network 81 or 84 to produce a pulse of relatively
short duration (the "short pulse") 155 on lines 83 or 84. Due to
the digital logic described above, each such pulse 155 results
in a pulse output on line 114 of Flip-Flop 102, as shown in Fig-
ure 11, but does not trigger the Two Bit Counter 91. The series
of pulses appearing on line 114 is shifted into the Data Input
of a Six Bit Shift Register 103, conventional in the art, by the
inverted clock pulse train appearing àt the output of Inverter 98.
It should be appreciated that Shift Register 103 may comprise more
or less than six bits, depending on the number of sectors 66 in
a semi-circle between sectors S and T. The precise number of bits
in Shift Register 103 will equal the number of sectors 66 in a
semi-circle. ~-
Corresponding to the distribution of the marks 68 on
the sectors 66, the digital signal on line 114 represents a binary
., .
word. For example, corresponding to the distribution of the marks
:'
68 on the sectors 66 depicted in Figure 8, the digital word on line
114 will be "011000", as shown at line 114 in Figure 11. This
word will be shifted into Six Bit Shift Register 103, as already ~-
described, and then strobed into Latch 105 by a strobe pulse
appearing on line 123. The strobe pulse on line 123 is timed to
occur after the Shift Register 103 is fully loaded. Latch 105
may be any suitable memory device known in the art. For example,
assuming a Six Bit Shift Register 103, Latch 105 may comprise
six flip-flops, each connected to a cell in Register 103 the out-
put of which is strobed into the flip-flop according to principles
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well-known in the art. At the end of the detection process,
the Latch 104 may be reset by any suitable switch.
The digital word stored in Latch 105 is in the binary
form and is decoded by Binary to BCD Decoder 106, which may be a
conventional device known in the art. The decoded word, in BCD
form, is then fed to Mold-Number Display 107 and to Comparator 117, ~ -
as further described hereinafter.
A digital word identifying a defective mold is preset
and stored in Ejector Memory 118 and fed on line 119 to Comparator ~ -
117. Ejector Memory 118 may be a matrix of pushbutton switches
(not shown) arranged to provide a digitally coded number or word
which conforms to the coded number or word generated by Decoder
106. Comparator 117 may be a device conventional in the art which
compares the digital word generated by Decoder 106 to the digital
` word stored in Ejector Memory 118. If the two words match, Com- : -
parator 117 sends a control signal 120 to Ejector 121 whic~h en-
gages and ejects the bottle. If the words are not identical, then
~3 Ejector 121 is not activated and the entire detection process is ~Y~
repeated for the next bottle 16 in procession 12. :
', The digital word generated by Decoder 106 is also fed .
j to Mold-Number Display 107 which comprises an array of indicator
~ lights for displaying the word according to principles well-known
:~ n the art. ~:
Referring to ~igure 10, there is shown a set of Ear-
phones 127 for checking the pulse-width of the one shot pulses
~ on line 88, generated by One Shot Multivibrator 87, and a Latch and
`i~ Number Display 110 for checking the pulse repetition rate of the
pulses on line 97, generated by Astable Multivibrator 90. More
specifically, in making an audio check, the procession 12 is halt-
ed indefinitely and bottle 16 is spun in place. The pulses appear-
ing on line 90 at the output of AND gate 89 are amplified by ;;
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Amplifier 112 and fed on line 113 to Earphones 127. Thus, as
the bottle 16 spins in place, a series of one shot pulses is gen-
erated on line 88 each of which has a pulse-width less than the
pulse-width of the long pulse generated on lines 83 or 84 by
sectors S or T, but greater than the pulse-width of a short pulse
generated by any of the sectors 66 which have only one mark 68
therein. As a result, the pulses appearing on line 90 occur only
during a long pulse generated by the sectors S or T. If, however,
the pulse-width of a one shot pulse appearing on line 88 exceeds
the pulse-width of a long pulse generated by sectors S or T,
no pulse will be generated on line 90 and the absence of the
pulse will be detected by using Earphones 127. Similarly, if . ~ .
the pulse-width of a one shot pulse appearing on line 88 is less ~ :than the pulse-width of a short pulse generated by a mark 68 on -
a sector 66, than a spurious pulse will be generated on line 90
during the time that a short pulse is genera ted by a sector
66 and this spurious pulse, appearing at irregular intervals,
will be detected by use of the Earphones 127.
The pulse repetition rate of the pulses generated by
Astable Multivibrator 96 on line 97 can be checked to insure that
the pulses on line 97 overlap the shaped pulses appearing on lines
~4 or 84 so that the required Data Input signal will be generated .
on line 114. This is accomplished by Five Bit Counter 111 and
,, ; .
Latch and Number Display 110 in conjunction with AND gate 108.
In particular, the Five Bit Counter 111 counts the number of
pulses generated by Astable Multivibrator 96. Although Counter
111 is referred to as having five bits, it should be obvious that
the number of bits required depends on the pulse-width repetition
frequency of the clock pulses generated by Multivibrator 96 as
~ .,
well as the pulse-width of the shaped pulses on lines 83 or 84, to
ensure the proper Data Input signal on line 114 as already ex-
plained. Thus, depending on these parameters, Counter 111 may have
,, .
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1~4;~530
more or less than five bits. The count maintained by Counter 111
is fed into Latch and Number Display 110 which comprises conven-
tional s~orage and display circuitry previously referred to with
respect to Latch 105 and Mold-Number Display 107. The strobe
signal for Latch 105, appearing on line 123, will also appear
on line 109 since the inputs to AND gates 104 and 108 are the same, ;~
as shown in Figure 10. The strobe signal on 109, then, strobes ~-
the Latch and Number Display 110 to provide a visual indication -
Of the number of pulses generated by Multivibrator 96 during the
time that it is gated on by AND gate 95. In this manner, the
proper alignment can be maintained between the cloc~ pulses gen-
erated by Multivibrator 96 and the shaped pulses appearing on
lines 83 or 84 to generate the Data Input pulses to Six Bit
Shift Register 104 on line 114.
In summary, then, a transparent bottle 16 is trans-
ported by conveyor 14 and caused to rotate about its axis~as it
.. . ..
moves through the inspection area. During rotation of the bottle
~1 16, a digital number representing the arrangement of marks 68 on
~, the bottom wall 34 of bottle 16 is generated and compared to a pre- ~;
selected digital number which identifies a particular mold. If
the numbers match, an Ejector 121 is activated by a control signal
~ 120 to eject bottle 16 from the procession 12.
;~s Although in the preferred embodiment described, the
control signal 120 is used to eject a bottle associated with a
l defective mold, the signal 120 may also be used for other pur-
J poses. For example, signal 120 could be used to identify certain
bottles which will require special handling, or bottles which
are to be shipped to a specific destination, or bottles which are -
' to be selected for test purposes, and so forth.
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Further, in the preferred embodiment a Spectra-Physics
Model 155 Helium-Neon gas laser having a power of 1/2 milliwatt
and a wavelength of 6328 angstrons was used, however, it should
be obvious that other light sources which provide collimated beams
of light may also be suitable for use in the invention. Simi-
larly, although in the preferred embodiment an International Recti-
fier S0505 E8PL milicon photodetector was used, other photode-
tectors may also be suitable for use in the invention.
The present invention may be embodied in other specific
forms without departing from the spirit or essential attributes
thereof and, accordingly, reference should be made to the appended
claims, rather than to the foregoing specification as indicating -
the scope of the invention.
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