Spacer system for surface conveyor

A metering device is provided that is able to engage and release food stuff items that are being conveyed on a conveyor belt such that the relative positions of the multiple food stuff items on the conveyor belt are spaced at a predetermined interval. In addition, in a preferred embodiment, the metering device is used in combination with a sensing device that is located upstream of the metering device. The sensing device is able to detect the presence of a food stuff item upstream of the metering device such that the sensing device is able to control the engagement and release of the downstream food stuff items.

FIELD OF THE INVENTION 
The invention relates to a system for controlling the spacing between a 
series of work products moving along a surface conveyor. The items being 
conveyed typically relate to foodstuff products, such as circular cookies 
or crackers moving in series on one or more surface conveyors, moving from 
an oven to a packing machine. 
BACKGROUND OF THE INVENTION 
In order to economically produce and package fragile or delicate work 
products such as food items, it is desirable to minimize the amount of 
time it takes to convey an item from its production to its packaging. At 
the same time, it has also been desirable to maximize the efficiency by 
which the items are packaged by minimizing packaging errors. If items are 
inappropriately conveyed from a production station to a packaging station, 
packaging errors can occur. For example, with cookie-type or cracker-type 
foodstuffs, it is desirable to bake and transport the cookies on surface 
conveying systems with several parallel lines of cookies moving through 
the equipment. When the cookies are ready to be placed in their packages, 
the equipment typically orients a predetermined number of cookies in an 
edge-standing stack or "slug" and places the slugs of cookies in recesses 
of clear plastic cookie trays that become part of the package purchased by 
the consumer. A cookie tray may comprise several such recesses for 
receiving several slugs of cookies. If the timing of the delivery of the 
cookies that are delivered to the packaging station is irregular, the 
trays might not be properly filled. 
The failure to fill the tray with cookies typically is caused by two 
problems. First, if the foodstuff item, such as a cookie, is not properly 
aligned or centered in its row on the surface conveyor, it may fall out of 
its row, or the item may enter into the packaging station out of alignment 
with the packaging machine and be misfed to the packager. Either mishap is 
likely to cause the formation of an incomplete slug of cookies and the 
cookie tray will not be properly filled with cookies. Second, if an 
individual item is not properly spaced apart from another item along the 
path of the surface conveyor, maximum packaging speed and efficiency will 
not be obtained and will likely result in improperly and inefficiently 
loaded slugs and/or trays. For example, if the items are too close to each 
other on the surface conveyor, the packaging machine might not be able to 
accept all of the items. Or if the items are spaced too far apart on the 
surface conveyor, the packaging machine might not place a full load of the 
items in the container. 
Heretofore, the most common method for correcting packaging errors that 
were due to the improper way in which cookies were spaced or aligned prior 
to entering a packaging station was to employ several workers to watch 
over the forming slugs and trays to remove the trays that were improperly 
loaded. In the past, if the packaging error was due to a missing item, the 
usual way to prevent that void from offsetting the entire packaging 
process was to shut down the conveyor line to correct the void. These 
correction methods are, of course, expensive and are an inefficient means 
of conveying and packaging foodstuff items. 
In other types of foodstuff industries, attempts have been made to maximize 
the efficiency of conveying an item from a production station to a 
packaging station. For example, U.S. Pat. No. 3,429,416 teaches that a 
plurality of fingers can be used to keep candy bars from fishtailing while 
the candy bars are being conveyed downstream to a packaging station, and 
also teaches a separate "hold" or gate/bar mechanism that functions to 
align the candy bars into columns. 
U.S. Pat. Nos. 3,854,569 and 3,970,189 disclose a complex arrangement of a 
product holder, alignment rail, and a pair of angled thrusting devices. At 
varying stages in the conveyance stream, the product holder, alignment 
rail, and the thrusting devices act to align the confection items into 
rows and columns. However, none of these patents teach adequately aligning 
and spacing food items such as cookies or crackers on a surface conveyor 
system and they also fail to teach a means for detecting the absence of an 
upstream item, and how to adjust the spacing of the downstream item. 
SUMMARY OF THE INVENTION 
Briefly described, the present invention comprises a method and apparatus 
for adjusting the spaces between cookies or other duplicate items of 
comparable size and weight that are being conveyed on a surface conveyor 
system in parallel paths, such as from an oven, through a cooling system 
and ultimately to a packaging machine. In the disclosed embodiment, the 
items being conveyed are duplicate, circular cookies with approximately 
round perimeter edges, and the cookies are transported on a surface 
conveyor system having parallel conveyor tapes, all moving at the same 
rate toward the packaging equipment. However, the principles of the 
invention can be applied to other types of items and conveyors. 
The system, referred to as a metering system, is suspended over all of the 
lines of cookies and includes a cookie gate for each line of cookies on 
the surface conveyor system. Each cookie gate functions as a gate to block 
the movement of the cookies as the cookies travel with the surface 
conveyor system, and all of the cookie gates usually oscillate in unison 
toward and away from the conveyor surface to alternately engage and 
therefore block the movement of the cookies on the conveyor surface and 
later to release the cookies and allow the cookies to pass on the conveyor 
surface toward the packaging machine, etc. All of the cookie gates are 
mounted on a common oscillatory support shaft in such a manner that each 
individual cookie gate can freely rotate about the support shaft 
independently of the other cookie gates. 
Each cookie gate is supported on the common support shaft in an 
off-balanced arrangement and tends to tilt downwardly under the influence 
of gravity toward its surface conveyor line into blocking relationship 
with respect to a line of cookies moving with the surface conveyor. 
However, a releasable latch is mounted between the cookie gate and the 
oscillating drive shaft and normally locks the gate to the drive shaft, 
causing the gate to oscillate upwardly and downwardly with the drive 
shaft, away from and then toward blocking relationship with respect to the 
cookies moving with the surface conveyor system. When the latch of a gate 
is opened, the gate remains under the influence of gravity in its down, 
blocking position with respect to the oncoming cookies, while the 
oscillating shaft and the other gates continue to oscillate. 
Each cookie gate includes a pair of fingers which straddle the desired 
center line of travel of the cookies passing beneath the gate, and the 
fingers are positioned a distance apart that is less than the diameter of 
the circular cookies, and the fingers are oscillated toward and away from 
its line of cookies such that the fingers usually are lowered onto the top 
trailing portion of a cookie passing there beneath. As the cookie beneath 
the fingers moves further downstream by the surface conveyor system, the 
fingers drop off the cookie and down into juxtaposition with the surface 
conveyor to block the next oncoming cookie. The fingers engage the leading 
circular edge of the oncoming cookie to retard its downstream movement on 
the moving surface conveyor. The next oncoming cookies begin to accumulate 
behind the stopped leading cookie at the cookie gate, so that the cookies 
form a queue in edge-to-edge abutment. This creates a space between the 
just released cookie and the cookies blocked at the gate. 
The fingers of each cookie gate engage and stop a cookie for a 
predetermined amount of time during the normal operation of the metering 
system. The predetermined amount of time is determined by the speed of the 
surface conveyor system and by a computer that controls the oscillation 
speed of the oscillating drive shaft. 
A cookie sensor means is positioned upstream of the cookie gates and 
detects the cookies moving toward the gates. If one of the lines of 
cookies does not have enough cookies to properly form a complete slug of 
cookies to be moved to the awaiting package, the computer will unlock the 
latch of that gate so that the gate moves by gravity into blocking 
relationship with respect to the oncoming cookies. The preceding slug of 
cookies therefore will be short at least one or possibly several of the 
cookies to form a complete slug. However, cookies will begin to accumulate 
at the lowered cookie gate, and the computer will again latch the gate to 
the drive shaft at the beginning of the formation of the next slug of 
cookies. Therefore, the next slug of cookies will be formed with the 
proper number of cookies in the slug. 
Inasmuch as the drive shaft normally operates all of the cookie gates in 
unison, and the surface conveyor system moves all of the cookies at the 
same rate, the metering system will form slugs of cookies which are equal 
in number, which are spaced apart equally, and which are aligned both 
longitudinally and laterally as they move from the metering system toward 
the packaging machinery. 
The drive shaft of the metering system pauses with the gates all in their 
down, cookie blocking positions for an additional time interval after each 
slug of cookies has been formed. This causes a gap to be formed between 
the slugs on the surface conveyor so that the packaging machine has 
additional time in which to handle the previously formed slug. 
Further, when the fingers of each cookie gate move down into juxtaposition 
with respect to the surface conveyor so as to block the next oncoming 
cookie, the rounded edges of the cookie tend to cause the cookie to center 
itself between the fingers of the cookie gate, so that all of the cookies 
leaving the metering system will be substantially perfectly aligned as 
they move from the metering system to the packaging machine. 
Thus, it is an object of the present invention to provide an inexpensive 
system for forming multiple lines of cookies with a predetermined number 
of cookies forming slugs of cookies, and with the spaces between the 
cookies in a slug being substantially equal. 
Another object of the present invention is to provide a method and 
apparatus for aligning duplicate items into rows and columns on a surface 
conveyor system. 
It is a further object of the invention to provide an improved method and 
apparatus for delivering the proper number of items to a packaging machine 
from each row of a multiple row conveyor system. 
It is another object of the invention to provide a system for controlling 
the spacing of items moving in parallel lines on a surface conveyor 
system, so as to place a predetermined number of the items in each line 
equidistant from one another so as to form a slug of the items in each 
line that will be received in a container, and then to form a larger gap 
between the slugs of items, so that the slugs can be received in a 
container and move with the container out of the way of the next oncoming 
slug. 
Other objects, features and advantages of the present invention will become 
apparent upon reading the following specification, when taken in 
conjunction with the accompanying drawings.

DETAILED DESCRIPTION 
Referring now in more detail to the drawings, in which like numerals 
indicate like parts throughout the several views, FIG. 1 illustrates a 
surface conveyor system 10 that delivers cookies to a packing machine 12. 
The packing machine is of conventional construction and includes a tray 
conveyor 14 which delivers cookie trays laterally across the delivery end 
of the surface conveyor system 10. The cookies are arranged in slugs, and 
the slugs of cookies are delivered to the cavities of the trays. The 
filled cookie trays are delivered by the delivery end 16 of the tray 
conveyor to the next operating station (not shown) where the filled cookie 
trays are placed in bags. 
Metering system 20 is positioned upstream of the cookie packaging machine 
12 on the surface conveyor system 10. Generally, metering system 20 
includes gate assembly 22, drive motor 24, cookie detector system 26 and 
computer 28. Gate assembly 22 and cookie detector system 26 are both 
suspended over the surface conveyor system 10, allowing the cookies to 
pass there beneath. 
As illustrated in FIG. 2, gate assembly 22 comprises drive shaft 30 that 
extends across and over the surface conveyor system 10, with the drive 
shaft being supported at its opposite ends in bearings 32. Drive shaft 30 
is connected at one of its ends through intermediate crank linkage 34 to 
motor 24. The drive shaft 38 of motor 24 rotates crank 40, and 
intermediate link 44 oscillates follower link 46 which oscillates drive 
shaft 30. 
A plurality of duplicate cookie gates are freely rotatably mounted to drive 
shaft 30. As illustrated in FIG. 2, cookie gate 48a is mounted to drive 
shaft 30 and is positioned over the line of cookies moved on surface 
conveyor tape 50a in the direction indicated by arrow 51. Likewise, cookie 
gate 48b is mounted over cookie conveyor tape 50b. As shown in FIG. 3, 
each cookie gate includes a sleeve 52 and a pair of fingers 54 and 56 are 
each mounted at one end to the sleeve and extend parallel to each other 
and in the direction of movement of the surface conveyor system from the 
sleeve, with the end portions 54a and 56a being angled downwardly toward 
conveyor tape 50a. 
Each cookie gate includes a cookie gate latch assembly. For example, cookie 
gate 48a includes latch assembly 58a which includes a housing 60 rigidly 
mounted to the drive shaft 30, a solenoid mounted to the housing, and a 
latch 64 operated by the solenoid 62. A slot or protrusion 66 is formed on 
sleeve 52 for engaging the latch 64. With this arrangement, when drive 
shaft 30 is oscillated by motor 24 and its crank linkage 34, the cookie 
gate latch assembly, such as latch assemblies 58a and 58b, will oscillate 
as indicated by doubled-headed arrow 68. When latch 64 is projected in 
front of its protrusion 66, the cookie gate, such as cookie gate 48a, will 
move upwardly in unison with the drive shaft, as indicated by arrow 70. 
Thus, all of the cookie gates, 48a, 48b, etc. will move upwardly in 
unison. However, when solenoid 62 is energized to retract latch 64 from 
its protrusion 66 of its sleeve 52, the latch assembly 58a will continue 
to oscillate in unison with the drive shaft as indicated by arrow 68, but 
the sleeve 52 of the cookie gate will not be locked to the drive shaft 30, 
leaving the cookie gate without power to oscillate. Inasmuch as the 
fingers 54 and 56 of each cookie gate cause the cookie gate to be mounted 
in an off-balance relationship about drive shaft 30, the unlocked cookie 
gate will tend to move under the influence of gravity in a downward 
direction so that the end portions 54a and 56a, for example, will fall 
toward engagement with the conveyor tape 50a, so that the ends of the 
fingers are in contact, or at least juxtaposed against the upper surface 
of the conveyor tape. 
When the cookie gate is to be reconnected to drive shaft 30, the solenoid 
62 is de-energized, causing its spring to thrust its latch 64 toward 
locking engagement in front of protrusion 66 of sleeve 52, so that the 
cookie gate now resumes oscillation with drive shaft 30. 
Cookie detector system 26 of FIG. 1 comprises a detector, such as a 
photocell 72 (FIG. 5) for each line of cookies. Each photocell 72 detects 
therebeneath a cookie moving on the surface conveyor system. The detection 
of each photocell is communicated to computer 28, and the computer 
utilizes this information to control the cookie gate latch assembly of 
each cookie gate. 
OPERATION 
Separate lines of cookies move on the surface conveyor system 30 beneath 
the cookie detector system 26 and beneath the gate assembly 22 toward the 
packaging machine 12, where the cookies are placed in trays, and the trays 
are conveyed away to be placed in bags. 
The cookies are to be arranged on the surface conveyor in groups or "slugs" 
of a predetermined number of cookies so that when the slugs of cookies 
reach the packaging machine 12, the cavities of the cookie trays will be 
properly filled with cookies. 
When all of the cookie gates 48 are locked to the drive shaft 30, the 
cookie gates will move upwardly away from the surface conveyor system in 
unison with the oscillating drive shaft. When the cookie gates oscillate 
so that their fingers move down into juxtaposition with respect to the 
surface conveyor passing therebeneath, the fingers will block the next 
oncoming cookie. For example, FIGS. 4 and 5 illustrate the fingers moved 
down against the surface conveyor and blocking the movement of the 
oncoming cookie 8b. The previous cookie 8a which passed beneath the cookie 
gate before the cookie gate moved into blocking relationship now continues 
to move with the surface conveyor away from the blocked cookies 8b, 8c, 
etc. In the meantime, the other oncoming cookies 8c, etc. begin to 
accumulate in edge-to-edge abutment with previously blocked cookies to 
form a queue of cookies at the cookie gate. 
When a new slug of cookies is to be formed by the metering system, the 
drive shaft 30 will pause with all of its cookie gates in their down 
positions, so as to form a gap 74 behind the last cookie of the previous 
slug of cookies and in front of the first cookie 8b that will be in the 
next slug of cookies. Since all of the gates will be in their down 
positions, gaps 74 will be formed in all of the lines of cookies on the 
surface conveyor system. 
Once the proper gap 74 has been established in each line of cookies, the 
drive shaft 30 will begin its normal, more rapid oscillations. The gates 
48a, 48b, etc. will then be raised and lowered so as to control the spaces 
to be formed between the cookies. FIG. 6 shows a cookie gate being lifted 
so as to move out of blocking relationship with respect to the oncoming 
cookie, therefore releasing the cookie immediately beneath the fingers. 
FIG. 7 illustrates the gate assembly tilting back in the opposite 
direction so that its gate fingers move back toward the surface conveyor 
system. If the cookie 8b has not yet cleared the fingers, the fingers 
simply lightly engage the top surface of the cookie 8b and allow that 
cookie to continue its movement with the surface conveyor system. However, 
the cookie 8b eventually moves out from beneath the fingers of the cookie 
gate and the fingers then drop off the trailing edge of the cookie, into 
blocking relationship with respect to the next oncoming cookie. Thus, the 
next cookie, 8c, is temporarily blocked until a space of a predetermined 
size is created between these two cookies. 
Because the latch 64 of each gate is in front of the protrusion 66, the 
tilting of the latch assemblies back to the down position does not force 
the gates downwardly, thereby allowing gravity to bias the gates toward 
the down, blocking positions. This avoids damage to the cookies when the 
gates engage the tops of the cookies, as shown in FIG. 7. 
This motion continues until all of the cookies in the slug passing beneath 
the cookie gate have been properly spaced. When the last of the 
predetermined number of cookies has been released by the gates, the gates 
will be moved back down into blocking relationship with the oncoming 
cookies for an extra interval of time, so as to create the gap 74 between 
the just released slug of cookies and the next oncoming slug of cookies. 
In a situation where one of the lines of cookies does not receive enough 
oncoming cookies to properly form a slug of cookies having a predetermined 
number of cookies, the photocell 72 of that line of cookies will detect 
the absence of sufficient numbers of cookies, and this information will be 
communicated to the computer 28. Upon receiving this information, the 
computer will energize the solenoid latch of the cookie gate latch 
assembly 58 of that line of cookies, which allows the cookie gate to fall 
under its own weight into blocking relationship with respect to the 
oncoming cookies. Even though the drive shaft 30 continues to oscillate, 
the line of cookies that is deficient in number will be blocked until 
enough cookies have been moved into the cookie gate, and until the 
beginning of the next slug commences. In other words, the preceding slug 
will be allowed to progress without having enough cookies to completely 
fill the slug, but the next oncoming slug will be properly filled with 
cookies. This operation increases the likelihood that the succeeding slugs 
of cookies will be fully filled with cookies. 
While the surface conveyor system has been disclosed as a series of 
conveyor tapes moving in parallel so as to move the lines of cookies in 
parallel, it will be understood by those skilled in the art that a single, 
broad surface conveyor could be used instead. Further, while the cookie 
sensing means has been described as being a plurality of photocells 72, 
with each photocell positioned over a line of cookies, it should be 
understood that other types of sensing means can be used. 
When the metering system is used with circular items, such as cookies 
having a round perimeter, it will be appreciated that the distal ends of 
the cookie gates, such as the downwardly turned ends 54a and 56a of cookie 
gate 48a, are spaced apart across the center line of movement of cookies, 
so that the rounded edge of the cookie at the gate will engage the spread 
apart fingers. If the center of gravity X (FIG. 4) of the cookie to engage 
the finger ends of the gate is generally beneath the fingers, when the 
leading rounded edge of the cookie engages one finger end, the conveyor 
tends to pivot the cookie so that its leading edge also engages the other 
finger end. This action between the surface conveyor, cookie and finger 
ends and the rounded cookies always causes the cookie blocked by the 
fingers to be centered at the gate. Therefore, a substantially perfect 
line of cookies will be released by each cookie gate. 
Inasmuch as all of the cookie gates are operatively mounted to the 
oscillating drive shaft 30, they operate in unison and release cookies in 
unison. This means that the cookies also will be laterally aligned as well 
as longitudinally aligned as they approach the cookie packaging machine. 
While the foregoing specification and drawings have disclosed the preferred 
embodiment of the invention, it will be understood by those skilled in the 
art that variations and modifications thereof can be made without 
departing from the spirit and scope of the invention as set forth in the 
following claims.