Patent Abstract:
A card dispensing system for dispensing cards along a conveying surface which conveys sliced products downstream of a slicer for packaging the sliced products. A hopper contains a stack of cards which are withdrawn from the hopper by a suction force provided via at least one suction cup. The suction cup is moveable vertically to retrieve and remove the card from the hopper. The suction cup is moveable laterally to move the card into a receiving position where a card clamp on a damp carriage arrives to receive the card. Suction force on the card is released when the card damp damps down on the card. The clamp carriage moves the card from the receiving position to the staging position where a nip engages with the card to feed the card through a junction in the conveyor line just as a food product passes over the junction.

Full Description:
This application is a nationalization of PCT application PCT/US2010/054156 filed on Oct. 26, 2010, and claims the benefit of U.S. Provisional Patent Application 61/255,087 filed Oct. 26, 2009 and U.S. Provisional Patent Application 61/255,445 filed Oct. 27, 2009. 
    
    
     FIELD OF THE INVENTION 
     This invention relates in general to food packaging systems, and methods of dispensing cards, in particular, for packaging stacked slices of food products. 
     BACKGROUND OF THE INVENTION 
     Sliced and shingled food products such as bacon is often placed on a cardboard sheet and inserted into airtight packaging. The cardboard sheet often provides information about the product, such as weight, nutritional information, and grade. In the past, segregated groups of slices were placed on the cardboard sheet manually by attendants located along a packaging and manufacturing line. This is often time consuming and lacking in economic efficiency. 
     Most bacon lines today are equipped with an automatic cardboard sheet dispenser, such as the dispensing systems disclosed in U.S. Pat. Nos. 4,328,657 and 4,452,031. Cardboard sheet dispensers are incorporated in bacon or other food product slicing machine lines that are used to group slices in shingled, segregated batches of predetermined weight. The dispensing system dispenses a cardboard sheet onto a conveying surface, such as a conveyor belt, in synchronization with the movement of batches along the conveying surface, so that the movement of the individual batches along the conveyor belt is used to dispose the batches onto the dispensing sheet of cardboard. The batches of sliced product disposed onto a cardboard sheet are transferred further downstream for additional packaging and other processes. 
     U.S. Pat. No. 4,452,031 discloses a card dispenser including a hopper for receiving vertically stacked cardboard sheets and a base having a plurality of strippers to support the stack of sheets while assuring that only one sheet at a time is removed from the hopper. U.S. Pat. No. 4,328,657 discloses a card dispenser including a hopper for receiving vertically stacked cardboard sheets with a plurality of restrainers in supporting the stack of sheets and to fan the sheets to minimize sticking of the sheets to one another. A pick off assembly that removes the lower most sheet from the hopper and transfers it to the nip of a roller assembly is disclosed in both patents. The pick off assembly includes two piston cylinder arrangements which allows the first piston cylinder assembly to actuate between a vertical upright position and an inclined position where the sheet is picked up by a roller assembly. The roller assembly directs the cardboard sheet so it is moved by a pusher assembly to a location where the cardboard receives a batch of slices. 
     The present inventors have recognized that the known prior art card dispensing devices described, and others, have been disadvantageous for various reasons. Prior art dispensing systems lack the capacity to dispense and package sliced products at higher volumes. Prior art dispensing systems also lack the ability to adapt packaging process to accommodate different cards for various grades of meat product being packaged along the same processing line. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method and apparatus for dispensing cards for packaging predetermined quantities of sliced products. Presliced drafts are placed on an infeed conveyor where it passes under a product sensor station. A product sensor detects the sliced product, serves as a marker, and tracks the precise position of the draft along the conveying surface for proper card placement downstream. As the draft approaches the card assembly station dispensing the applicable card, a card is drawn from the bottom of a hopper via suction cups positioned at the bottom of the hopper. A clamp, connected to a clamp carriage, moves towards the awaiting card being held by the suction cups to the receiving position, where the clamp grasps the card, simultaneously triggering release of the suction. The clamp carriage will move the card into a staging position beneath the infeed conveyor, and position the leading edges of the card in a card nip roller area to await a signal. Upon the signal, which activates the dispensing mechanism and simultaneously signals the release of the card clamp, the card nip will close, pinching the card between a nip drive roller and an idle roller to roll the card into position directly beneath the oncoming product. 
     In another aspect, the present invention provides a method and apparatus for dispensing cards corresponding to different grades of sliced products along a conveying surface, thus allowing a more efficient method of packaging differently graded drafts. As the sliced drafts enter the product sensor station, the product sensor detects the sliced product on the infeed conveyor and signals a camera that the product is entering the photo area. The camera captures a digital image of the draft. Grading software is used to determine the grade of the draft by analyzing the image captured. Card assembly stations situated along the conveying surface each comprise a hopper containing cards with a particular grade label. Once the grading software determines the grade of the draft, a signal is sent to the card assembly station with the card corresponding to the appropriate grade level to activate the dispensing mechanism, such that a card displaying the proper grade information for the draft is dispensed as the draft moves along the conveying surface. Other card assembly stations with card corresponding to a grade level inapplicable to the draft passing by on the conveying surface remain dormant as the draft passes. 
     Numerous other advantages and features of the present invention will be become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic side view of the product processing line. 
         FIG. 2  is a perspective view of the processing line with a card assembly station. 
         FIG. 3  is a perspective view of the side of the hopper. 
         FIG. 4  is a top view of the hopper. 
         FIG. 5  is a perspective view of the card assembly station with the top and bottom portions of the card assembly station separated. 
         FIG. 6  is a perspective view of the card clamp and card nip. 
         FIG. 7  is a schematic diagram of the suction cups. 
         FIG. 8  illustrates a card in its staging position. 
         FIG. 9  illustrates a card being dispensed between two conveying surfaces. 
         FIG. 10  illustrates bacon being disposed onto the card. 
         FIG. 11  is a schematic block diagram of one embodiment of a control system that may be used in the card dispensing apparatus. 
         FIG. 12  is a top view of the card clamp in its receiving and staging positions. 
         FIG. 13  is a side view of the clamp carriage and card clamp. 
         FIG. 14  is a perspective view of the staging area with parts removed for clarity. 
         FIG. 15A  is view of the card clamp and clamp carriage in the longitudinal direction of travel. 
         FIG. 15  B is a side view of the card clamp and clamp carriage. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     While this invention is susceptible of embodiment in many different forms, there are shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated. 
       FIG. 1  illustrates the primary components of the card dispensing system. The card dispensing system comprises a product grading station  100 , an infeed conveyor  150 , an intermediate conveyor  390 , an exit conveyor  400  and two card assembly stations  200  which are situated along the product line. The various components of the invention will now be discussed in detail. 
     As illustrated in  FIG. 1 , the product grading station  100  is situated above, and near the beginning of the infeed conveyor, whereby products are conveyed in a direction “A.” The product grading station comprises a camera  110 , a product optical sensor  120  and lights  130 . The product sensor  120  senses incoming drafts  140  and signals to the camera  110  that a product is entering the photo area, indicated as “B” in  FIG. 1 . Lights  130  provide sufficient illumination for capturing a digital image of the draft. The digital image is transferred to vision system software, such as the one described in U.S. Pat. No. 6,997,089, which analyzes the image captured and compares relative fat areas and lean areas to determine a fat to lean ratio for grading purposes. Upon determination of the grade of a particular draft, information is sent to the appropriate card assembly station  200  with the card containing grade information corresponding to the grade of the draft. 
       FIG. 1  shows two card assembly stations  200  situated along the conveying line. Each card assembly station corresponds to a dispensing of different cards, for example, grade 1 or grade 2 cards. Each card assembly station dispenses cards at the junction between adjacent conveyor belts.  FIG. 1  illustrates a card  380  being dispensed between the intermediate conveyor  390  and the exit conveyor  400 . 
     The conveying line shown in  FIG. 1  comprises of an infeed conveyor  150 , an intermediate conveyor  390 , and an exit conveyor  400 . A person having skill in the art given the present disclosure will recognize that additional intermediate conveyors and card assembly stations can be incorporated into the conveying line so as to allow for packaging of additional grades of sliced product. 
       FIG. 2  illustrates a card assembly station situated adjacent to the product line. As seen in  FIG. 2 , the card assembly station comprises a top portion  222  and a bottom portion  224 . The top portion  222 , as illustrated in  FIG. 3 , comprises a hopper  210  surrounded by a hopper guard  214 . The hopper guard  214  encloses at least a portion of the hopper  210 , and provides support for the hopper. The hopper is defined by four corner panels  212  arranged in accordance with the dimensions of the cards being dispensed from the hopper  210 . Support fingers  216  at the bottom of the hopper releasably hold and support the cards until they are ready to be removed from the hopper  210 . 
     Cards are removed from the hopper  210  through the use of suction cups  220  situated below the hopper  210 .  FIG. 4  illustrates a top view of an empty hopper  210 , with suction cups  220  situated below. 
       FIG. 5  illustrates the separation of the top portion  222  of the card assembly station from the bottom portion  224  of the card assembly station. The top portion  222  is pivotally attached to a shaft  226 , allowing the top portion to pivot away from the conveying surface, and away from bottom portion  224 . When the top portion  222  and bottom portion  224  are in alignment, as shown in  FIGS. 2 and 4 , the hopper guard  214  and bottom enclosure  218  forms a substantially continuous skirt which houses the hopper  210  and the suction cups  220 . Pivoting the top portion  222  away from the bottom portion  224  allows the bottom portion, which is enclosed on the sides by bottom enclosure  218 , to be accessible from above, as illustrated in  FIG. 5 . 
     The suction cups  220  are situated within the bottom portion  224  of the card assembly station, as illustrated in  FIG. 6 .  FIG. 7  illustrates the suction cups connected to a rigid horizontal block  300 . The suction cups are raised and lowered according to the upward and downward motion of the rigid horizontal block  300 . The suction cups are raised from their resting height “X” a distance “R” to a height “Y,” allowing the suction cups  220  to come into contact with the bottom card (not shown) in the hopper  210 . The suction cups  220  exert a negative pressure in order to attach the bottom card. The bottom card is removed from the hopper by lowering the suction cups  220 . The removal of the card from the hopper is facilitated by the support fingers  216 , which comprise an inclined surface comprising a series of gradual ridges  217  along the side in contact with the card ( FIG. 7 ). This gradual stepping down of the inclined ridges  217  works in conjunction with the flexible nature of the cards to allow the edges to decrease its bending as the card is gradually pulled in a downward direction from the hopper along the support fingers  216 . 
     As illustrated in  FIG. 7 , the horizontal block  300  is attached to a central rod  310  by a fastener  311 . Two guiding rods  340  are fixed to the block  300  on either side of the central rod  310 . The raising and lowering of the horizontal block  300  is achieved by the upward and downward movement of the central rod  310  telescopically within a central tube  320 . The central tube is situated within a T-shaped base member  330 . The base-member  330  also comprises two channels within each of the arms of the T-shape, which extend through the entire depth of the arms. The guiding rods  340  are fitted through the channels, and move vertically with the movement of the horizontal block  300 . The guiding rods  340  assist in keeping the horizontal block  300  from inadvertently pivoting around the central rod  310 , and ensure that the movement of the horizontal block  300  is even within the same vertical plane. The central rod is connected at its base  324  to a double acting air cylinder  325 , the top portion of which is nested within the bottom  326  of the T-shaped base member  330 . The dual acting pneumatic cylinder comprises two air ports  327   a ,  327   b  which can alternately act as pressure air in or air bleed out, to actuate the upwards and downward motion of the central rod, and correspondingly the horizontal support block  300  on which the suction cups are attached. 
     Each suction cup  220  is connected to a stem  321 , which extends upward from the horizontal block  300 . The stem  321  and the suction cup  220  are connected to form a central channel through which a negative pressure can be applied to create a vacuum. L shaped air channels  322  ( FIGS. 6 and 7 ) are situated on either side of the horizontal block  300  to allow for a negative air pressure flow generated by an external source, to flow through the suction cups  220  and stems  321  and through a channel formed within the block  300 . 
     Once the suction cups  220  have removed a card  344  from the hopper  210  by attaching to the card and lowering the card, the card is lowered until the suction cups  220  are in their resting position “X,” as illustrated in  FIG. 7 . When the suction cups  220  pull a card down, a portion of the edge of the card closest to the conveying surface rests on a bottom guiding strip  357 , illustrated in  FIGS. 4 and 5 , which helps guide the lateral movement of the card between a top guiding strip  356  and the bottom guiding strip  357  as the card is moved to a staging position beneath the conveying surface. Both the top guiding strip  356  and the bottom guiding strip  357  have curved lips  358 ,  359  at the edge first coming in contact with the card to facilitate reception of the card, as illustrated in  FIG. 5 . 
     The suction cups  220  continue to hold the card in place until a card clamp  240  moves laterally along clamp carriage guide arms  246  from its card staging position beneath the conveying surface, towards the “receiving position,” where an awaiting card is held by the suction cups  220 . When the card clamp  240  reaches the awaiting card, the card clamp, comprising a top plate  241  and a bottom plate  242  as illustrated in  FIG. 6 , will close on a central portion of the awaiting card, simultaneously triggering the release of the card by the suction cups. 
     As shown in  FIGS. 1 and 6 , the card clamp is mounted on a clamp carriage  230  which moves bi-directionally along clamp carriage guide rods  246 . The clamp carriage  230  is preferably composed of plastic. As the card clamp  240  moves laterally along clamp carriage guide rods  246  to the staging position beneath the conveying surface  150  at a card nip roller area  350 , a portion of the card becomes increasingly engaged between the guiding strips  356 ,  357 .  FIG. 6  illustrates a card clamp  240  which has just begun to move the card along the clamp carriage guide rods  246  towards the staging direction. A portion of the card  344  slides under the top guiding strip  356 . The guiding strips  356 ,  357  help maintain the leading edge of the card  245  in alignment with the card nip roller area  350 . 
     For illustration purposes,  FIG. 12  shows the card clamp  240  in both the receiving position  240 A and the staging position  240 B. A clamp carriage drive motor  270  ( FIG. 13 ) rotates the clamp carriage drive arm  260  to move the clamp carriage  230  laterally along the clamp carriage guide rods  246  between the receiving position and the staging position ( FIG. 12 ). The clamp carriage drive arm  260  pivots about a shaft  261 , as illustrated in  FIGS. 14 and 13 . The clamp carriage drive arm  260  pivots along an arc  550  which moves the clamp carriage along the clamp carriage guide rods  246  ( FIG. 12 ). 
     The pivotal motion of the clamp carriage drive arm  260  is transferred into a lateral movement through the use of a carriage bar  500  attached to the bottom of the clamp carriage  230 , as shown in  FIGS. 6 ,  12 , and  13 . The carriage bar  500  is attached to the clamp carriage  230  using screws  501  as illustrated in  FIGS. 15A and 15B . The carriage bar  500  comprises a groove  510  on the underside. The clamp carriage drive arm  260  comprises a pin  551  on the end of the arm. The pin  551  is of a size suitable for fitting into the groove  510 , and slideably engaging with the groove. When the clamp carriage drive arm  260  moves along an arc  550 , the pin  551  slides along the groove  510  in various positions. When the clamp carriage drive arm is in a position perpendicular to the clamp carriage guide arms  246 , as shown in  FIG. 12 , the pin  551  is a the position in the groove  510  farthest away from the card. This position is illustrated as  551 A in  FIG. 13 . When the clamp carriage  230  is in the staging position or in the receiving position, the pin is situated at a position  551 B′ or  551 B respectively, as illustrated by  FIGS. 12 and 13 . 
       FIGS. 15A and 15B  illustrates the clamping mechanism in detail. The top plate  241  is attached to a top plate strip  570  along the edge of top plate that is above the clamp carriage  230 . The top plate strip is secured to the top plate  241  through the use of top plate screws  560  as illustrated in  FIGS. 13 ,  15 A, and  15 B. The bottom plate  242  is attached to the clamp carriage  230  through the use of bottom plate screws  561 . The bottom plate extends beyond the clamping region  562  ( FIG. 15  B) to cover an air chamber  580  formed in or bored into the clamp carriage  230 . The air chamber  580  in the clamp carriage is a recessed portion in the clamp carriage  230  which contains a clamp piston  530 . The bottom plate  242  covers an open top of the chamber  580 . The clamp piston moves up and down in the air chamber  580  and is sealed to the air chamber sidewall by a seal ring  581 , carried in a groove on the piston  530 . The piston  530  is connected to the top plate strip  570  by a fastener  531  and a surrounding tubular spacer  532 . The fastener  531  is threaded into a threaded hole in the top of the piston  530  and when drawn tight, clamps the tubular spacer between the strip  570  and the piston  530 . The tubular spacer  532  slides within an annular air seal  533  carried by the bottom plate  242 . 
     Two air nozzles  540   a ,  540   b  are connected to bottom plate  242 , and serve as alternate air inlet and outlet nozzles for the air chamber. The clamp piston moves upward as a result of pressurized air input into the nozzle  540   b , with nozzle  540   a  acting as an air bleed, and moves downward to clamp a card as a result of pressurized air input into the nozzle  540   a , with nozzle  540   b  acting as an air bleed. The nozzle  540   a  opens to a top side of the piston  530  within the chamber  580 , and the nozzle  540   b  is open to a bottom side of the piston  530  within the air chamber  580 , through a channel  540   c . Two rod-shaped top clamp guides are attached to the top plate strip  570  on either side of the clamp piston  530 . These clamp guides  520  are fitted through two channels  521  which span the entire depth of the clamp carriage  230 . The clamp guides  520  assist in keeping the top plate from inadvertently pivoting around the clamp piston  530  or tilting from a true vertical movement. 
       FIGS. 8 and 15  illustrate the card in its staging position, where the leading edges of the card are positioned in the card nip roller area  350 . The card nip roller area  350  comprises a motorized drive roller  351  and an idler roller  352 . Upon a grading signal, the dispensing mechanism activates, causing the card nip to close and grasp the card between the drive roller and the idler roller. To close the nip, a pneumatic cylinder actuator  353  presses the idler roller  352 , by pivoting an idler roller- mounting lever, toward the drive roller  351 , to pinch the card therebetween. The closing of the card nip is simultaneous with the card clamp releasing its hold on the card, thus allowing the card to roll up between adjacent conveying surfaces ( FIG. 9 ), and to dispense beneath an oncoming draft ( FIG. 10 ). Preferably, the drive roller  351  is made of rubber or other gripping surface. 
     As the card is fed through the rollers, it reaches a guide plate  254  ( FIGS. 6 and 10 ) situated on the opposite side of the rollers. The guide plate  254  is inclined upwards and in the direction of travel A, of the product draft. The guide plate  254  assists in guiding the leading edge of the card upwards between adjacent conveying surfaces. A second guide plate  256  as illustrated in  FIG. 10 , can be used for additional guidance of the card. The dispensing of the card is synchronized with the movement of oncoming product draft such that the movement of the product draft along the conveying surface allows the product draft to be deposited on the card as it emerges from between the adjacent conveying surfaces. The product draft deposited on the dispensed card then continues down the conveying surface for further processing, such as packaging. 
     In operation, a product draft moves along the infeed conveyor and passes under the product grading station  100 . The product grading station comprises a product sensor  120  which notes the position of the product draft  140  on the conveying surface so as to allow the product to be tracked as it moves along the conveying surface ( FIG. 1 ). After the product draft passes the product sensor  120 , it enters the photo area, designated as “B” in  FIG. 1 . In the photo area, a camera  110  captures a digital image of the product draft. The digital image of the product draft is transferred to a vision system software for analysis. The vision software, such as the one disclosed in U.S. Pat. No. 6,997,089, analyzes the captured image by comparing the lighter areas indicating fat, with the darker, lean areas of the product draft. A fat-to-lean ratio is determined, and compared with a operator programmed fat-to-lean parameter to determine under which grade the draft being analyzed should be categorized, for example, grade 1 or grade 2. In other embodiments, more than two different grades of draft product can be sorted and disposed on appropriate cards with labeling information corresponding to the grade of the draft, in accordance with the invention. 
     Once a grade is determined for a product draft, a signal is sent to the card assembly with the cards having labeling information corresponding to the grade of the particular draft, to activate the dispensing mechanism. 
     As the draft product moves along the conveying surface, the card assembly station(s) with cards that are inapplicable to the grade of the particular draft remains dormant and does not dispense a card between the conveying surface. The product draft by-passes the inapplicable card assembly station(s) without incident, and thus is only deposited on the appropriate card dispensed between the conveying surfaces at the card assembly station dispensing cards with the applicable grade information. For example, in a card dispensing system in accordance with the invention for dispensing two different cards with different grade information (“a two grade dispensing system”), the draft product can by-pass a dormant first assembly station, and be deposited on the card dispensed by the activated second assembly station. In a three grade dispensing system, the draft product can be deposited on a card dispensed by any one of the three card assembly stations that is activated to move the card from its staging position to being dispensed, while by-passing the other dormant card assembly stations with cards of inapplicable grades positioned in the staging station, waiting for the appropriate grade signal to activate their dispensing mechanism. 
       FIG. 11  is a schematic block diagram of one embodiment of a control system that may be used with the card dispenser.  FIG. 11  illustrates a central controller  900  which receives a signal from the position sensor system  920  used in conjunction with the product sensor  120 . The central controller  900  also receives a grade signal  930  from the vision software system  910 . Upon receiving the grade signal  930 , the central controller  900  sends a signal to the appropriate dispensing mechanism  960  to activate it. The controller simultaneously activates the dispensing system  960  which causes the card nip to close, by the pneumatic actuator  353 , and sends a clamp signal  950  to the card clamp  240  to release so the card can be dispensed. Once the card clamp  240  releases the card to the card nip, the card clamp is sent back to the receiving position to receive the next card. At a time before the card clamp  240  moves back to its receiving position, a signal  940  is sent to the suction cups to move up and pull down the next card in the hopper, so that the card is already awaiting the card claim  240  when it returns to its sliding position. Once the clamp is in the receiving position, the central controller  900  sends a signal to close the clamp around the card, and simultaneously triggers a release of the suction force. The card clamp proceeds towards the staging position, and waits for the next activation signal of the dispensing mechanism. 
     From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. 
     All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

Technology Classification (CPC): 1