Vacuum gripper device for slicing machine
1 Apr. 29, 1975 VACUUM GRIPPER DEVICE FOR SLICING MACHINE [75] Inventor: Ihor Wyslotsky, Hazelcrest, Ill.  
 [73] Assignee: Thermoplastic Engineering, Inc.,  
 Chicago, Ill.  
 [22] Filed: Nov. 8, 1973 [21] Appl. No.: 413,797  
  52 us. c1. 21411.5; 83/409; 83/437 51 Int. Cl B23q 5/22 58 Field of Search 214/1 BS, 1 BT, 1.1-1.5-  
 FOREIGN PATENTS OR APPLICATIONS l.286 466 H1969 Germany 279/3 Primary Examiner-Frank E. Werner Almrney, Agent, or Firm-Guy A. Greenawalt [57] ABSTRACT A product gripping device for a slicing machine which is characterized by a carriage frame adapted to be mounted in sliding relation on the product supporting table of the slicing machine and having a plurality of vacuum cup formations in the face of the carriage against which the heel of the product is adapted to be held with each vacuum cup formation having an associated valve arrangement which is automatically operable to effect gripping of the product when the heel forming or trailing end of the product is engaged with the leading or forward face of the carriage.  
 5 Claims, 7 Drawing Figures VACUUM GRIPPER DEVICE FOR SLICING MACHINE This invention relates to apparatus for use in slicing food products which are in the form of loaves. slabs. or the like. such as bologna. bacon. cheese or similar products and is more particularly concerned with improvements in gripping devices for holding the product while it is moved along a table towards a cutting blade or other slicing element.  
  Machines have long been provided for slicing loaf or slab type food products. such as bologna. bacon. cheese or other products which are customarily prepared in large loaves or slabs and which are adapted to be sliced for sale or use. In the most commonly used type of commercial slicing machine the product is moved along a table toward a slicing knife or blade which is revolving at high speed. The product is secured at the trailing end by a gripping device which is advanced along the table surface toward the cutting blade so as to push the product into the cutting area or zone. Generally. such gripping devices or pushers have been in the form of a carriage forming frame having a product engaging face and a plurality of mechanical gripping elements or fingers which are operated to dig into the product near the end thereof and clamp the product to the face of the pusher. This results in a waste end portion of the product when the pusher or gripper device reaches a point where the slicing must be discontinued to avoid damaging contact between the slicing blade and the product gripping or holding elements. In an effort to reduce the size of the waste end resulting from the use of mechanical gripping elements it has been suggested that the product be held on the pusher face by vacuum means and it is a principal object of the present invention to provide a product gripping device for a slicing machine which employs an improved vacuum arrangement for gripping the trailing end of the product so as to hold it on the face of the gripper device.  
  A more specific object of the invention is to provide a product gripping device for holding the trailing end ofa product while it is advanced to a slicing element of a product slicing machine which effectively secures the trailing end of the product by vacuum means while permitting the advance of the product along a cutting path of maximum length so as to reduce to a minimum the size of the waste heel which remains when the slicing operation is completed.  
  A still more specific object of the invention is to provide an improved gripper device for a slicing machine which comprises a mechanism mounted on a carriage adapted to be slidably mounted for movement along the product supporting table of the slicing machine and an arrangement in the form of a vacuum cup in the product engaging face of the device which is operable to hold the trailing end face of the product in tight engagement with the face of the pusher forming gripper device so as to permit maximum slicing of the product with a minimum waste product end or heel portion when the slicing is completed.  
  Another object of the invention is to provide a product gripping device for use on a slicing machine which is in the form ofa slidably mounted pusher with a prod uct engaging face in which there is provided one or more suction. gripping arrangements automatically operable when the product is engaged with the pusher face to grip the product and hold it for movement with the pusher.  
  Still another object of the invention is to provide a product gripping device for incorporation in a slicing machine so as to serve as a pusher for feeding the lead ing end of one or more products to a slicing element wherein the gripping device or pusher is in the form of a slidably mounted carriage with a product engaging face having a plurality of suction cup arrangements each of which has incorporated therein a valve assembly which normally closes the connection with a vacuum source and which is automatically opened by engaging the product against a protruding portion of the valve assembly.  
  These and other objects and advantages of the invention will be apparent from a consideration of the vacuum gripper device which is shown by way of illustration in the accompanying drawings wherein:  
  FIG. 1 is a perspective view of a vacuum gripper device which incorporates therein the principal features of the invention. the view showing portions of a typical product slicing machine and illustrating the intended use of the gripper device;  
  FIG. 2 is an elevational view showing the product engaging forward face of the gripper device of FIG. I;  
  FIG. 3 is a sectional view taken on the line 33 of FIG. 2;  
  FIG. 4 is an elevational view showing the rear face of the gripper device;  
  FIG. 5 is a cross-sectional view taken on the line 55 of FIG. 4. to an enlarged scale:  
  FIG. 6 is a cross-sectional view taken on the line 6-6 of FIG. 4. to an enlarged scale: and  
  FIG. 7 is a perspective view of one of the valve elements associated with each of the vacuum cup formations.  
  Referring first to FIG. 1 there is illustrated a portion of a well-known type of commercial slicing machine II] which is employed generally for slicing food products. such as. sausage and similar luncheon meats which are produced in loaf or stuffed casing form and sliced for serving or packaging for marketing. A product gripping device 12 which embodies the principal features of the invention is shown mounted on a carriage support member 14 which is in turn mounted for movement longitudinally of the product supporting table I6 of the slicer. with a connection to a suitable means for reciprocating the gripper 12 in a path which. when the gripper is advanced toward the slicing blade l8 will bring the leading ends of a pair of sausage products 20 which are held on the gripper 12. into the path of the blade 18.  
  The product gripping device 12. which also serves as a pusher for moving the product 20 into the cutting path of the slicing blade 18. comprises a generally rectangular plate 22 of substantial thickness. When in use. as shown in FIG. I, the plate 22 is disposed in a vertical plane with its forward or leading face 24 adapted to serve as a gripper face for the product. The rearward face 26 is provided with a pair of studs 28 (FIGS. 3 and S) for bolting the device to the supporting carriage member 14 on the slicing machine.  
  The plate 22 is provided in its forward face 24 with a plurality of vacuum cup formations or arrangements 30 which are aligned across the bottom portion of the face 24 and adjoin each other. Each vacuum cup formation 30 is derived by cutting in the face 24 a series of concentric grooves or recesses 32 which results in relatively sharp pointed concentric separating rib formations 38. and 42 the outer extremities of which are in a plane set inwardly relative to the plane of the face 24. The circular ribs 42 of adjoining cup formations 30 merge at a point indicated at 44 in FIG. 2.  
  The rear face 26 of the plate 22 is recessed at 46 (FIGS. 3 to 6] along the bottom portion to provide for mounting therein a cover plate 48 which is in alignment with the vacuum cup formations 30 and which may be secured by screws or other suitable fasteners. Back of each vacuum cup formation 30 the plate 22 is further recessed to provide a series of circular chambers 50 of substantial depth which are connected by conduit forming recessed areas 52 constituting vacuum passageways and which form vacuum chambers when the device is in operation. A bore 53. paralleling the reces ses 52. is adapted to be connected to a vacuum pump (not shown) or other vacuum source through a suitable connection with the small bore 54 in the back face 26 and bores 55 and 56 form passageways connecting the bore 53 with the passageways 52 so as to provide for application of vacuum in the recesses 50. The outer ends of the bores 53. S5 and 56 are closed by plugs indicated at 58 which permits access to the bores if desired. Each ofthe vacuum cup formations 30 has a connection with the associated chamber 50 by means of small passageways 60 opening at opposite ends in the groove 34 and the chamber 50. respectfully. The groove 32 is also connected with the chamber 50 by means of a small passageway or bore 62 which constitutes a part of an automatic valve arrangement for opening and closing the connecting passageways between the vacuum cup formation and the vacuum source.  
  A valve forming member 64 (FIG. 7) is disposed in each chamber 50 (FIGS. 3. 5 and 6) which comprises a valve body in the form of a pin 66 and a circular plate 68 extending in a radially directed plane intermediate the ends of the pin 66 and having a shallow recess 70 in a major portion of the one face thereof. The plate 68 is of somewhat smaller diameter than the diameter of the circular chamber 50. The valve member 64 is positioned in the chamber 50 with the one end of the pin member 66 extending into the bore 62 which is of a somewhat larger cross sectional diameter than the cross-sectional diameter of the pin end and with the opposite pin end aligned with a blind bore 72 in the cover plate 48 which serves as a limit stop for pin movement. The member 62 is backed by a coil spring member 74 which is seated in the plate recess 70 at one end and abuts the cover plate 48 at the opposite end. The spring 74 normally urges the member 64 toward closed posi tion. as shown in the empty vacuum cup position in FIG. 3. the plate 68 seating in the bottom of chamber 50 and closing the vacuum ports or passageways 60. The pin end then projects through the bore 62 and beyond the extremities of the ribs 38, 40, 42 where it will be engaged and depressed when the end of a product is engaged with and forced against the operating face 24 of the device thereby compressing spring 74 and opening the valve for the application of suction through the passageways 60 and 62. The member 64 and the cooperating elements act as a poppet valve in controlling the vacuum applied through the associated cup formation which valve is automatically opened when the product to be attached is pressed against the face 24 and automatically closed when it is freed by removal of the product.  
  The operation and use of the gripper apparatus will be apparent from the foregoing description. The poppet valve arrangement enables individual control of the vacuum to the plurality of vacuum cup formations in a multiple cup unit. as shown, with the individual cup formations being activated by placement of the product against the same. The dimensions and relative placement ofthe vacuum cup arrangement may be changed. of course. for handling products of different size and end contour. As indicated in FIG. 1. a number of relatively small size products. for example. sausage products in relatively small diameter casings. may be held on the gripper device when the device is constructed with the particular vacuum cup arrangement which is illustrated.  
 I claim:  
  1. A product gripping device for incorporation as a pusher in a product slicing machine of the type in which a product is advanced on a supporting surface to a slicing device. said gripping device comprising a base member in the form of a plate of relatively rigid material having a face adapted to be disposed in a generally vertical plane on the sliding machine and having one or more vacuum cup formations in said face. each said vacuum cup formation comprising at least one continuous groove which opens on said face and which is defined by at least one rib formation spaced inwardly of the outer perimeter of said groove. said rib having a relatively sharp projecting edge adapted to bite into the product so as to form a closed chamber when a face of a product to be sliced is pressed against the same. said base member having means forming a plurality of passageways into said chamber for connecting said chamber to a vacuum supply source and a valve forming mechanism which is normally closed and which has means operable by pressure engagement to open the valve for applying vacuum so as to exhaust the associ ated chamber and hold the product face pressed against said vacuum cup formation.  
  2. A product gripping device as set forth in claim 1 wherein said means forming said passageways includes a chamber adjoining said continuous groove. with relatively small passageways forming a plurality of connections between said groove and said chamber. and said valve forming mechanism having a valve body disposed in part in said chamber and in part in a passageway connecting said chamber and said groove. the latter part in the normally closed position protruding into said groove and constituting said means operable by pressure engagement of the product to move the valve toward open position.  
  3. A product gripping device as set forth in claim 1 wherein each of said vacuum cup formation comprises a plurality of concentric grooves separated by rigid rib formations in concentric spaced relation and each of said rib formations having a relatively sharp projecting edge which will serve to bite into the product. with the inner ribs terminating in a plane set in from the product engaging face of the gripping device.  
  4. A product gripping device as set forth in claim I wherein said means forming a passageway for connecting the vacuum cup formation to a vacuum supply includes a chamber adjacent said vacuum cup formation which is connected by passageways with said vacuum cup formation and a spring pressed valve disposed in said chamber which valve has a body in the form of a pin with a radially extending plate portion intermediate the pin ends. one end of the pin being slidable in a bore in the wall separating the cup formation and said chamher. with the plate portion backed by a spring member and serving to normally close the remaining connecting passageways with one end of the pin positioned so as to extend to a point where engagement with a product face will force the valve body to a depressed position and open the passageways.  
  5. A product gripping device for incorporation in a product slicing machine so as to engage the trailing end of a product and hold it in a predetermined path as it is advanced toward a slicing blade, said gripping device comprising a base plate member with means for mounting the same on a movable carriage. a plurality of closely spaced vacuum cup formations in the vertically disposed forward face of said base plate each said vacuum cup formation comprising a plurality of continuous grooves opening on said face. which are defined by spaced continuous ribs having relatively sharp projecting edges adapted to bite into a product pressed against the same so as to co-operate in forming said grooves into closed chambers of progressively larger size in the direction outwardly of the center of said vacuum cup formation when a product is engaged with said base plate face. said vacuum cup formations each having an associated vacuum chamber back of the same with conduit forming bores connecting the grooves of each said cup formation and the associated chamber. conduit forming means connecting the vacuum chambers and adapted for connection to a vacuum source. and a valve means in each of said chambers which is spring pressed to normally close said connecting bores, said valve means comprising a stem member in the form of a pin and a web member extending radially of the axis of said pin. said valve pin and web member being positioned in said vacuum chamber with an end of said valve pin seated in slidable relation in one of said bores and with the end of said pin member projecting outwardly of the adjacent projecting rib edges when the valve is in the closed position so as to be moved to an open position when a product face is pressed against the associated cup formation.