Conveyor chain

This application is a continuation of U.S. patent application Ser. No. 10/185,997, filed Jun. 27, 2002 now U.S. Pat. No. 6,523,462.

The invention relates to food processing systems for processing an elongated strand of food product in a casing having tubular segments serially joined by pinched connection segments, e.g. hot dogs, sausage links, etc.

The invention arose during continuing development efforts directed toward subject matter such as shown in U.S. Pat. Nos. 6,086,469 and 6,056,636. In such systems, strands of sausage are made on high speed machines by extruding meat emulsion into an elongated casing. The meat-filled casing is then twisted to create sausage links. The linked strand is then discharged from the sausage making machine. Loops of sausage comprising a plurality of links are deposited on moving hooks of a conveyor. The ultimate length of a given strand is determined by the length of the casing being filled. When a casing has been filled, the sausage making machine is stopped; the casing is tied off or closed to prevent any meat emulsion from exiting the rear most end of the casing; a new casing is then placed in position to be filled; the machine is restarted and the cycle repeats itself. The linked and looped sausage strand or strands are periodically removed from the conveyor or otherwise transported to a food processing station which normally cooks, smokes or treats the sausage strand before packaging for final delivery to the consumer. With sausage machines creating up to 30,000 sausages per hour, the handling of the production of even a single machine is a significant task. Any inefficiency in the process translates into increased cost of production which is reflected in the price of the products to the consumer.

The present invention is directed to improvements in the above noted system, and in particular to providing alignment of the twisted pinched connection segment between tubular segments of the strand and the hooks on the conveyor receiving such strand from the strand producing machine. This is desired to ensure that the strand lay across the hook at a pinched connection segment between tubular segments, FIG. 20 ; and prevent the meat casing from laying across the hook at a midpoint of the tubular segment, FIG. 21 , which would deform the hot dog, sausage link or the like.

FIG. 1 is a side elevation view of a system for processing an elongated strand of food product in accordance with the invention.

FIG. 2 is a perspective view of a portion of the system of FIG. 1 illustrating operation.

FIG. 3 is like FIG. 2 and shows further sequential operation.

FIG. 4 is like FIG. 3 and shows further sequential operation.

FIG. 5 is like FIG. 4 and shows further sequential operation.

FIG. 6 is like FIG. 5 and shows further sequential operation.

FIG. 7 is a top plan view of a portion of the system of FIG. 1 .

FIG. 8 is a sectional view taken along line 8 — 8 of FIG. 7 .

FIG. 9 is a sectional view taken along line 9 — 9 of FIG. 7 .

FIG. 10 is a side elevation view of a portion of the system of FIG. 1 .

FIG. 11 is a schematic plan view illustrating problems encountered in the absence of the present invention.

FIG. 12 shows a portion of the structure of FIG. 11 .

FIG. 13 is a schematic plan view like FIG. 11 but illustrating the present invention.

FIG. 14 is like FIG. 12 but illustrates the present invention.

FIG. 15 is a schematic illustration overlying portions of FIGS. 11 and 13 .

FIG. 16 is like FIG. 13 and shows an alternate embodiment.

FIG. 17 shows a portion of FIG. 13 and illustrates loading.

FIG. 18 is an end view further illustrating the loading of FIG. 17 .

FIG. 19 is like FIG. 17 and shows the loaded condition.

FIG. 20 schematically shows the desired loaded condition.

FIG. 21 schematically shows an undesired loaded condition.

FIG. 22 is a further schematic illustration similar to FIG. 14 and further illustrating the invention.

FIG. 1 shows a food processing system 30 like that shown in above noted U.S. Pat. Nos. 6,086,469 and 6,056,636, incorporated herein by reference. The system processes an elongated strand 32 of food product in a casing 34 having tubular segments 36 serially joined by twisted pinched connection segments 38 . The system includes a conveyor 40 having a chain 42 traversing in a horizontal plane around a sprocket 44 , FIGS. 2 , 7 , at a strand loading station 46 , FIG. 1 , adjacent a discharge station 48 of a strand producing machine 50 having discharge looper horn 52 which rotates in a counterclockwise path as shown at 54 , as viewed from the right. Sprocket 44 rotates about a vertical axis 56 , and rotates counterclockwise as shown at 57 , FIG. 2 , as viewed from above. Chain 42 has a plurality of chain pins 58 connected by respective links such as 59 . Rollers such as 60 , FIGS. 1 , 8 – 10 , are mounted to selected lower chain links for rolling along support rails 61 . The structure and operation described thus far is in the prior art, for example as in the incorporated '469 and '636 patents. Chain 42 is preferably a #60 stainless steel roller chain, 0.75″ pitch, and carries the food product to one or more downstream processing stations, such as a cooking oven, and then is unloaded, and returns to loading station 46 .

Some of the chain pins have respective stainless steel studs such as 64 mounted thereto, preferably by welding to the link therebelow. Each stud has a bore 66 therethrough defining a pivot axis 68 parallel to the direction of chain travel 70 . A plurality of hooks 72 are provided, each having a normally vertical shank 74 with an upper end 76 extending laterally from vertical shank 74 into bore 66 in pivotal relation, and having a lower distal hook end 78 . A cam 80 at the loading station cammingly engages the hook at vertical shank 74 and cams the hook upwardly to an upwardly cammed pivoted position, FIG. 4 , receiving strand 32 at a reference loading point 82 , FIGS. 11 , 13 , at the loading station. This is sequentially illustrated in FIGS. 2–6 , wherein in FIG. 2 solid line hook 72 is initially in a vertically depending position, and then in FIG. 3 begins to pivot upwardly as it is cammed at leading cam edge 83 of cam 80 , and then in FIG. 4 the shank 74 is substantially horizontal, and then in FIG. 5 begins to pivot back downwardly along trailing cam edge 84 of cam 80 , and then in FIG. 6 returns to vertical. The camming action of hooks 72 is like the prior art, except for the mounting of the hooks. In the prior art, a plastic stud similar to stud 64 is mounted to a lower chain link 59 between chain pins, not to a chain pin.

FIG. 11 schematically illustrates operation of the above described system but without the benefit of the present invention. The chain has a plurality of groups of chain pins, each group having a leading pin 92 , a middle pin 94 , and a trailing pin 96 . The studs are connected to the middle pins, for example as shown at stud 64 connected to middle pin 94 . As the chain traverses around the sprocket as shown at arrow 57 , the orientation of the hooks as they arrive at reference loading point 82 is not consistent, and furthermore the arrival time spacings between adjacent hooks is not consistent. FIG. 11 shows hook shank 74 b in its upwardly pivoted horizontal position. FIG. 11 shows the projections of hook shanks 74 a and 74 c as if they were pivoted to their upward horizontal position, for illustration and comparison purposes. As shown, the angular distance between shanks 74 a and 74 b is 53.03 degrees, while the angular distance between shanks 74 b and 74 c is 26.67 degrees. The linear distance between hook ends 78 a and 78 b is 5.887 inches, while the linear distance between hook ends 78 b and 78 c is 4.107 inches. The angle between radial line 100 and pivot axis 68 a is 96.67 degrees. The angle between radial line 102 and pivot axis 68 b is 83.33 degrees. The angle between radial line 104 and pivot axis 68 c is 96.67 degrees. This is undesirable because of the noted inconsistent orientations of shanks 74 as they arrive at reference loading point 82 , and the inconsistent arrival time spacings thereof. One solution to the noted differential spacing problem would be to vary the speed of conveyor 40 and/or the discharge rate of strand producing machine 50 hook to hook, for example by increasing the speed of conveyor 40 or decreasing the discharge rate of machine 50 after hook 72 a passes reference loading point 82 to accommodate the greater spacing to the next hook 72 b , and then decreasing the speed of conveyor 40 or increasing the discharge rate of machine 50 after hook 72 b passes reference loading point 82 to accommodate the shorter distance to the next hook 72 c . The present invention addresses and solves this differential spacing problem in a much simpler manner.

FIG. 13 shows the present invention and illustrates the spacing equalization afforded thereby, including identical orientation of the hooks at reference loading point 82 , and presentment of the hooks at the reference loading point 82 at identical arrival time spacings between adjacent hooks for a given constant rotation speed of sprocket 44 , such that a respective pinched connection segment 38 , FIG. 20 , aligns with a respective hook without varying the speed of conveyor 40 nor the discharge rate of strand producing machine 50 . In FIG. 13 , the noted leading, middle and trailing chain pins of each group lie in a straight rectilinear line, including at the loading station, for example as shown at chain pins 92 b , 94 b , 96 b lying in a straight rectilinear line 106 coincident with pivot axis 68 b . In contrast, in FIG. 11 the counterpart pins 92 b , 94 b , 96 b do not lie along a straight rectilinear line at the loading station. As shown in FIG. 13 , the angular spacing between shanks 74 a and 74 b is 40 degrees, and the angular spacing between shanks 74 b and 74 c is 40 degrees. The linear displacement between hook ends 78 a and 78 b is 4.976 inches, and the linear spacing between hook ends 78 b and 78 c is 4.976 inches. The angle between radial line 100 and pivot axis 68 a is 90 degrees. The angle between radial line 102 and pivot axis 68 b is 90 degrees. The angle between radial line 104 and pivot axis 68 c is 90 degrees. As shown in FIG. 14 , chain pins 92 b , 94 b , 96 b define a rectilinear line as shown at 106 , wherein the angle between the center of the first and third chain pins 92 b and 96 b is 180 degrees. In contrast, in FIG. 12 , corresponding chain pins 92 b , 94 b , 96 b do not lie along a straight rectilinear line, and the angle between the center of first pin 92 b and third pin 96 b is not 180 degrees, but rather 166.67 degrees. Further in FIG. 14 , third pin 96 b of its respective group and first pin 92 c of the next group define a rectilinear line 108 therebetween. The angle between lines 106 and 108 is 160 degrees. Chain pins 92 c , 94 c , 96 c lie along a straight rectilinear line 110 . The angle between lines 110 and 106 is 140 degrees. Chain pins 92 a , 94 a , 96 a lie along straight rectilinear line 112 .

The noted straight rectilinear lines 106 , 110 , 112 , etc. are preferably provided by modifications of the sprocket 44 . FIG. 15 shows in dashed line the sprocket 44 of FIG. 11 , and shows in solid line at 44 a the sprocket as modified in accordance with the present invention. Sprocket 44 has a plurality of teeth 110 separated by roots 112 and engaging the chain pins. Sprocket 44 a likewise has a plurality of teeth 110 a separated by roots and engaging the chain pins. In modified sprocket 44 a , the roots 112 a at the chain pins having a stud 64 have a deeper radial depth than the remaining roots 112 b . The deeper radial depth at 112 a seats chain pin 94 b further rightwardly in FIG. 13 than in FIG. 11 toward the center 114 of the sprocket. In contrast, the root depth at 112 in FIG. 15 maintains the orientation of chain pin 94 b as shown in FIG. 11 . This is further illustrated in FIG. 22 wherein chain pin 94 b of FIG. 11 is shown in solid line at position 113 as provided by root depth 112 . In contrast, chain pin 94 b of FIG. 13 is shown in dashed line in FIG. 22 at position 115 as provided by deeper root depth 112 a of FIG. 15 . The radially inward displacement from position 113 to position 115 is shown at 116 .

In the preferred embodiment, sprocket 44 a has a plurality of groups of roots, each group having a first root 112 b , FIG. 15 , receiving first and third chain pins such as 96 b and 92 c , FIG. 13 , therein with no tooth therebetween, and a second root 112 a receiving the second chain pin 94 b therein. Root 112 b has a greater circumferential width than 112 a . Root 112 a has a greater radial depth than root 112 b . This skipped tooth arrangement provides easy orientation of the chain on the sprocket, i.e. chain pins having studs 64 go in the single root, while chain pins not having studs go in the double width root. In an alternate embodiment, as shown at sprocket 44 b , FIG. 16 , no teeth are skipped, and each root has the same width, and a marker or indicator such as 118 is provided corresponding to the deeper depth root for the chain pin with the stud 64 .

The precise alignment, orientation and spacing enabled by the invention facilitates loading of the strand onto the hooks as desired, FIGS. 17–20 . The noted hook orientation mechanisms provided by the noted chain pin relation and sprocket modifications orient the hooks in identical orientations at reference loading point 82 and present the hooks at such reference loading point at identical arrival time spacings between adjacent hooks for a given constant rotation speed of the sprocket, such that a respective pinched connection segment 38 aligns with a respective hook along shank 74 in its upwardly cammed pivoted position at reference loading point 82 without varying the speed of conveyor 40 nor the discharge rate of strand producing machine 50 . In further preferred form, a proximity sensor/reflector 120 , FIG. 7 , is adjustably mounted to sprocket 44 a at adjustment plate 122 having arcuate slot 124 for passing beneath proximity signal sender 126 , FIG. 1 , for providing a feedback signal through controller 128 to strand producing machine 50 for indicating angular position of the sprocket for synchronizing alignment of the noted pinched connection segments and hooks.

It is recognized that various equivalents, alternatives and modifications are possible within the scope of the appended claims.