Abstract:
A high speed food article slicing machine with a slicing station, a moveable frame supporting a food article feed mechanism frame, a food article gate, and a safety guard system for detecting an intrusion into the machine. Food articles are loaded onto a lift tray and raised to a staging position where food articles are in contact with a food article gate. The lift tray is located inline with the food article feed paths such that lateral shifting of food articles into the feed paths is not needed. Food article grippers, individually driven along feed paths by an overhead conveyor, move food articles over the food article gate towards the slicing station. The food article gate functions to assist in removal of food article end portions. The slicing machines utilizes a horizontally radiating laser intrusion detector to shut down systems when an unwanted intrusion is sensed.

Description:
[0001]    This application claims the benefit of U.S. Provisional Application No. 61/343,551, filed May 1, 2010. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Many different kinds of food articles or food products, such as food slabs, food bellies, or food loaves are produced in a wide variety of shapes and sizes. There are meat loaves made from various meats, including ham, pork, beef, lamb, turkey, and fish. The meat in the food loaf may be in large pieces or may be thoroughly comminuted. These meat loaves come in different shapes (round, square, rectangular, oval, etc.) and in different lengths up to six feet (183 cm) or even longer. The cross-sectional sizes of the loaves are quite different; the maximum transverse dimension may be as small as 1.5 inches (4 cm) or as large as ten inches (25.4 cm). Loaves of cheese or other foods come in the same great ranges as to composition, shape, length, and transverse size. 
         [0003]    Typically the food loaves are sliced, the slices are grouped in accordance with a particular weight requirement, and the groups of slices are packaged and sold at retail. The number of slices in a group may vary, depending on the size and consistency of the food article and the desire of the producer, the wholesaler, or the retailer. For some products, neatly aligned stacked slice groups are preferred. For others, the slices are shingled or folded so that a purchaser can see a part of every slice through a transparent package. 
         [0004]    Food articles can be sliced on high speed slicing machines such as disclosed in Published Patent Document WO 2010/011237 A1 or U.S. Pat. No. 5,628,237 or 5,974,925; or as commercially available as the Power Max 4000™ and FX180® slicers available from Formax, Inc. of Mokena, Ill., USA. 
         [0005]    The FX180® machine can be configured as an automatically loaded, continuous feed machine, or an automatically loaded, back-clamp or gripper type machine. 
         [0006]    For an automatically loaded, continuous feed machine, side-by-side upper and lower conveyor pairs drive food articles into the cutting plane. A gate is located in front of the conveyors. The initial food articles are loaded with leading ends abutting the gate. The gate is lowered and the food articles proceed into the conveyors. When the initial food articles are sliced to the extent that the trailing ends of the food articles clear the gate, the gate is raised and new food articles are loaded in the feed paths, held back by the gate. Shortly thereafter the gate is lowered and new food articles slide down to where lead ends of the new food articles abut trailing ends of the initial food articles being sliced. The new food articles are driven into the cutting plane trailing the initial food articles. Food articles are sequentially and continuously loaded in this manner, lead end-to-trailing end, in abutting contact with the preceding food articles. 
         [0007]    U.S. Pat. No. 5,628,237 and European patent EP 0 713 753 describe a back-clamp or gripper type slicing machine. According to this type of slicing machine, food articles are loaded onto a lift tray and the lift tray is raised to a ready-to-sweep position. Loaf grippers are retracted after the previous food articles are sliced. During retraction of the loaf grippers, loaf-to-slicing blade gate doors are closed and ends of the previous food articles are dropped through a loaf end door. After the grippers have reached the retracted position or “home position” remote from the slicing blade, a loaf sweep mechanism is activated, moving the food articles laterally together into the slicing position. A spacing mechanism moves down and spaces the food articles apart. The grippers then advance after it has been determined that the loaf sweep mechanism has moved the food articles to the slicing position. The grippers have onboard sensing mechanisms that are triggered by contact with the food articles. After sensing and gripping the food articles, the food articles are retracted slightly, and the loaf-to-slicing blade gate doors are opened and the food articles are advanced to the slicing plane of the slicing blade. The loaf sweep mechanism retracts and the loaf lift tray lowers, ready for the next reload cycle. According to this design, in practice, the reload cycle is accomplished in about eight seconds. In a high volume slicing operation, reload cycle time can be a significant limitation to optimum production efficiency. 
         [0008]    The machine disclosed in WO 2010/011237 A1 provides an automated, food article tray loading method and apparatus wherein food articles can be loaded into the lift tray into designated and separated lanes which automatically assume a preload condition, and after the food articles are loaded, food article separation is maintained on the lift tray. A food article transfer receives the food articles on the lift tray in their separated positions and transfers the food articles into the slicing feed paths while maintaining the separated positions. A food article end disposal system utilizes a transport that laterally moves end portions outside of the feed path and ejects the end portions as the transport is moved back into the feed path to receive the subsequent end portions. The machine utilizes food article grippers that are fixed onto conveyor belts which support and drive the food articles in the feed paths. 
         [0009]    The present inventors have recognized that it would be desirable to slice plural food articles with independent feeding and weighing capabilities, with hygienic and operational enhancements. 
       SUMMARY OF THE INVENTION 
       [0010]    The invention provides a mechanism and method for slicing multiple food articles with independency of feed rate and the ability to weigh each product group from each food article respectively to achieve optimal weight control and yield of each food article. 
         [0011]    The present invention provides a high speed slicing apparatus and a weighing and classifying conveyor combination that provides plural advantages in machine cost, productivity, food hygiene, and operation. 
         [0012]    The invention provides a lift tray that is located in line with the food article feed paths and is lowered to receive food articles and raised into the feed paths. There is no need for lateral shifting of food articles into the feed paths. Food article grippers are driven along the feed paths by an overhead conveyor. A laser food article end detection system is employed in each feed path to detect the terminal end of the food article to control the positioning of the gripper for that path. 
         [0013]    The invention provides the use of an automatic debris or scrap removal conveyor that also provides for end portion removal. 
         [0014]    The invention provides an automated cleanup position wherein the elevated food article feed mechanism can be collapsed to a more convenience plane or maintenance position, and the blade cover is automatically pivoted to a cleanup position. The combination provides for enhanced portion control and yield. A food article feed mechanism ensures accurate feeding by the use of servo driven and controlled feed belts and grippers. The slicing mechanism includes three independent drives for slicing multiple food articles simultaneously. 
         [0015]    An improved food article stop gate is provided that also serves as a door for the removal of food article end portions. 
         [0016]    A horizontally radiating laser intrusion detector is used to shut down systems when an unwanted intrusion by an operator is detected. 
         [0017]    An automated, food article tray loading method and apparatus is provided wherein food articles can be loaded into the lift tray into designated and separated lanes which automatically assume a preload condition, and after the food articles are loaded, food article separation is maintained on the lift tray. 
         [0018]    Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, and from the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a near side elevational view of a slicing machine and a weighing and classifying conveyor combination of the present invention; 
           [0020]      FIG. 1A  is an enlarged fragmentary view taken from  FIG. 1 ; 
           [0021]      FIG. 1B  is a perspective view of the slicing machine of  FIG. 1  in a clean-up configuration; 
           [0022]      FIG. 2  is a plan view of the combination of  FIG. 1  with some panels and parts removed or made transparent illustrating some underlying components; 
           [0023]      FIG. 2A  is a bottom perspective view of a portion of  FIG. 2 ; 
           [0024]      FIG. 3  is a sectional view taken generally along line  3 - 3  of  FIG. 2  with some panels and parts removed or made transparent and underlying components revealed; 
           [0025]      FIG. 4  is a schematic, sectional view taken generally along line  4 - 4  of  FIG. 6  with some panels and parts removed or made transparent and underlying components revealed; 
           [0026]      FIG. 5  is a schematic, sectional view taken generally along line  5 - 5  of  FIG. 6  with some panels and parts removed or made transparent and underlying components revealed; 
           [0027]      FIG. 6  is a sectional view taken generally along line  6 - 6  of  FIG. 3  with some panels and parts removed or made transparent and underlying components revealed; 
           [0028]      FIG. 7  is a fragmentary elevational view taken generally along line  7 - 7  of  FIG. 2  with some panels and parts removed or made transparent and underlying components revealed; 
           [0029]      FIG. 7A  is a fragmentary perspective view of a portion of  FIG. 7 ; 
           [0030]      FIG. 7B  is an enlarged fragmentary view of apportion of  FIG. 7A ; 
           [0031]      FIG. 7C  is an enlarged rear perspective view of a portion of  FIG. 7 ; 
           [0032]      FIG. 7D  is a top perspective view of a portion of  FIG. 7 ; 
           [0033]      FIG. 7E  is an enlarged fragmentary view of a portion of  FIG. 7 ; 
           [0034]      FIG. 7F  is an enlarged fragmentary view of an alternate embodiment of a lower conveyor. 
           [0035]      FIG. 8  is a fragmentary rear perspective view of the apparatus of  FIG. 1 ; 
           [0036]      FIG. 9  is a far side perspective view of the apparatus of  FIG. 1  with a lift tray in a lowered position; 
           [0037]      FIG. 10  is a top perspective rear view of the lift tray of  FIG. 9  with a tray platform removed; 
           [0038]      FIG. 11  is an enlarged, fragmentary near side perspective view of a portion of the slicing machine of  FIG. 1 ; 
           [0039]      FIG. 12  is an enlarged, fragmentary far side perspective view with a door removed to show underlying components; 
           [0040]      FIG. 13A  is a schematic diagram of the loaf feed apparatus in a first stage of operation; 
           [0041]      FIG. 13B  is a schematic diagram of the loaf feed apparatus in a second stage of operation; 
           [0042]      FIG. 13C  is a schematic diagram of the loaf feed apparatus in a third stage of operation; and 
           [0043]      FIG. 13D  is a schematic diagram of the loaf feed apparatus taken generally along line  13 D- 13 D of  FIG. 13C . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0044]    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. 
         [0045]    Published Patent Application No. WO 2010/011237 and U.S. Pat. No. 5,628,237 are herein incorporated by reference. 
       Overall Description 
       [0046]      FIGS. 1-3  illustrate a high speed slicing apparatus  100  and a weighing and classifying conveyor or output conveyor  102  according to a preferred embodiment of the invention. The slicing apparatus  100  includes a base section  104 , a collapsible frame  105 , an automatic food article loading apparatus  108  that receives food articles  110  to-be-sliced, a food article feed apparatus  120 , a food article end and scrap removal conveyor  122  ( FIGS. 13C and 13D ), a laser safety guard system  123 , a slicing head apparatus  124 , and a slice receiving conveyor  130 . The slicing head apparatus includes a slicing blade  125  that defines a slicing plane and a orifice plate or slicing block  126  that guides food articles into the slicing plane, the blade cutting closely to the orifice plate. The slicing apparatus also includes a computer display touch screen  131  that is pivotally mounted on and supported by a support  132 . 
       Base Section 
       [0047]    The base section  104  includes a compartment  136  having side walls  138   a,    138   b,  a bottom wall  140 , and an inclined top wall  142 . The apparatus  100  is supported on four adjustable feet  144 . The compartment  136  has a tapered side profile from back to front wherein the top wall  142  slants down from back to front. The slanted orientation of the top wall  142  ensures water drainage off the top of the compartment  136 . The compartment is supported on adjustable feet  144 . 
         [0048]    The compartment  136  includes a near side door  152 , a far side door  156  ( FIG. 9 ), and a rear door  162  that permit access into the compartment or to modules normally held within the compartment  136 . The compartment  136  typically affords an enclosure for a computer, motor control equipment, a low voltage supply, and a high voltage supply and other mechanisms as described below. The compartment may also include a pneumatic supply or a hydraulic supply, or both (not shown). 
       Collapsible Frame and Elevated Housings 
       [0049]    The base section  104  supports the collapsible frame  105  as shown in  FIGS. 1 ,  1 B and  9 . The collapsible frame  105  includes a foldable support mechanism  174  that supports a food article feed mechanism frame  190 . 
         [0050]    The foldable support mechanism  174  includes a servomotor  175  that drives a gear reducer  176  having a drive shaft  178  that extends out of far side of the compartment  136  ( FIG. 9 ). The drive shaft  178  is rotationally fixed to parallel levers  180   a,    180   b  which swing out with a turning of the drive shaft  178 . The levers  180   a,    180   b  are pivotally connected to a column  182  via a rotary connection  184 . The column  182  is pivotally connected at a pivot connection  192  to the frame  190  which supports the food article feed apparatus  120 . 
         [0051]    For cleaning and maintenance purposes, the collapsible frame  105  is collapsed down by actuating the servomotor  175  and gear reducer  176  to rotate the levers  180   a,    180   b,  which draws down the column  182  as shown in  FIG. 1B . The frame  190 , and all equipment supported thereby, is lowered for more convenient maintenance and cleaning as illustrated in  FIG. 1B . In some cases this eliminates the need for ladders or platforms when servicing the slicing apparatus  100 . 
         [0052]    The slicing head  124  is covered by a guard  119  that is attached to the frame  190  such that when the frame is pivoted down as shown in  FIG. 1B , the guard  119  is pivoted away from a slicing head base  117  to expose the slicing blade  125  and internals for cleaning and maintenance. 
         [0053]    Additionally, the elevation of the food article feed apparatus can be adjusted by using the servomotor to selectively pivot the columns  180   a,    180   b  and lower the rear of the frame  190 . At a front, the frame  190  is supported on a cross shaft  193  that is eccentrically fixed at each end to a round cam  194  ( FIG. 1A ). The cam is journalled in a round opening  195  in side supports  197   a,    197   b  and the cam is fixed for non rotation to the respective side support by fasteners  199 . The far side is shown in  FIG. 1A , with the understanding that the near side is mirror image identical across the longitudinal vertical center plane of the machine. As shown in  FIG. 1A , because the dimension “a” is smaller than the dimension “b”, the shaft ends can be temporarily loosened by removing the fasteners and the shaft and cams can be rotated 180 degrees about a centerline of the shaft, and the cams can be re-fastened to be fixed to the side supports. The elevation will be different between the two 180 degree adjustable positions. Thus, the machine will accommodate two different height settings for different types of food articles. 
       Food Article Feed Apparatus 
       [0054]    An upper conveyor assembly  530  of the food article feed apparatus  120  is shown in  FIG. 2 . The conveyor assembly  530  includes three independently driven endless conveyor belts  802 ,  804 ,  806 . Each belt  802 ,  804 ,  806  is identically driven so only the drive for the belt  802  will be described. 
         [0055]    The belt  802  is wrapped around a toothed front drive roller or pulley  812  and a back idler roller or pulley  816 . The belt  802  preferably has teeth that engage teeth of the two rollers  812 ,  816 . Each drive roller  812  includes a toothed outer diameter  812   a  and a toothed, recessed diameter  812   b.    
         [0056]    An endless drive belt  820  wraps around the recessed diameter  812   b.  The drive belt  820  also wraps around a drive roller  824  that is fixed to a drive shaft  828 . The drive shaft  828  extends transversely to the belt  802  and is journaled for rotation within a bearing  830  mounted to a near side frame member  836 . 
         [0057]    The drive shaft  828  penetrates a far side frame member  838  and extends to a bearing  843 , coupled to a gear reducer  842  mounted to a support frame  854 . The gear reducer  842  is coupled to a servomotor  850  that is mounted to the support frame  854 . 
         [0058]    The servomotor  850  drives the drive shaft  828  which turns the roller  824  which circulates the belt  820  which rotates the roller  812  which circulates the belt  802 . 
         [0059]    Three servomotors  850  are mounted to the support frame  854  and all are located within an upper compartment  855  that is supported by the frame  190 . 
         [0060]    The idler rollers  816  are provided with a pair of mirror image identical adjustable cam belt tension adjustment mechanisms  882   a,    882   b.  As shown in  FIG. 7A , each mechanism  882   a,    882   b  includes a fork  885  that is braced from the respective side frame member  836 ,  838  by an adjustable cam  883 . The fork  885  is guided by upper and lower pins  886   a,    886   b  so as to slide rearward and forward and has an end  891  that captures an axle  889  that rotationally supports the idle rollers  816 . For adjustment, the cam fastener  883   a  is loosened so as to be rotatable on the respective side frame member  836 ,  838 , rotated to achieve the desired belt tension, and then the cam fastener is tightened to hold the cam fixed. 
         [0061]      FIG. 7B  illustrates a gripper  894  used in cooperation with the belt  802 . The gripper  894  is mounted to a bottom run of the belt  802  and is translated along the food article path by the belt  802 . The gripper  894  is clamped to a belt joint and guide assembly  896  by a fixture  901  that engages the assembly  896  and is fixed thereto by a clamping set screw  897 . The assembly  896  comprises a pair of upper members  899  and a lower member  900 . The upper members  899  can include teeth  899   a  that mesh engage the teeth of the belt  802  once the members  899 ,  900  are fastened together to splice the free ends  802   e,    802   f  of the belt  802  ( FIG. 7D ). For clamping, fasteners  902 ,  904  ( FIG. 7D ) are provided which are inserted from above the members  899  through plain holes in the members  899  and tightly threaded into threaded holes in the member  900 . 
         [0062]    The block  900  includes guides  906 ,  907  that contain slide bearings  906   a,    907   a  composed of friction reducing material. The slide bearings  906   a,    907   a  partly surround longitudinal rails  912 ,  913  that are in parallel with, and straddle the belt  802 . The rails  912 ,  913  support the gripper along its working path from a retracted position to a fully forward position nearto the slicing plane. 
         [0063]    For each gripper there are two rails  912 ,  913  to support and guide that gripper. Thus, there are two rails that straddle the belt  804  and two rails that straddle the belt  806 . 
         [0064]    The gripper  894  is connected to the fixture  901  by a front plate  920  having a predominant lateral face and a rear plate  922  having a predominant longitudinal face. Each gripper  894  is provided with two air lines  930 ,  932  for two way pneumatic gripper open-and-close operability. 
         [0065]    The air lines  930 ,  932  are guided through lower rings  940  and upper rings  942  to an air tube storage area  950  above the food article feed apparatus  120  ( FIG. 7D ). The air tube lines are routed around weighted rollers or slides  951  that are guided by longitudinal slots  952  and extend to a source of pressurized air. Thus, the movement of the rollers or slides along the slots under force of gravity, will take up slack in the air tubes when the grippers  894  are moving toward, and when in, the retracted position. 
         [0066]    The gripper  894  travels from the retracted home position shown in  FIG. 7A  to the advanced, forward position approaching the slicing plane. 
         [0067]    The grippers  894  are as described in Published Patent Application No. WO 2010/011237, herein incorporated by reference. 
       Lower Conveyor 
       [0068]    As illustrated in  FIGS. 3 ,  6 ,  7 , and  7 E at a front end of the food article feed apparatus  120 , are three lower feed conveyors  992 ,  994 ,  998 , having endless belts  1002 ,  1004 ,  1008 , respectively. The endless belts  1002 ,  1004   1008  are independently driven and are directly opposed to pressure plates  1003 ,  1005 ,  1007  respectively. 
         [0069]      FIG. 6  shows the conveyor  992  has a drive roller  1010  having a central hub  1012  with a center bore  1014 . The drive roller  1010  has tubular stub axles  1016 ,  1018  extending from opposite ends of the central hub  1012 . The tubular stub axles  1016 ,  1018  are journaled for rotation by bearings  1020 ,  1022  that are fastened to carrier blocks  1023   a.    
         [0070]    The conveyor  994  includes a drive roller  1038  having a central hub  1042  with a bore  1044 . The drive roller  1038  has tubular stub axles  1046  and  1048  extending from opposite ends of the central hub  1042 . The tubular stub axles  1046 ,  1040  are journaled by bearings  1050 ,  1052  respectively that are attached to carrier blocks  1023   b.    
         [0071]    A motor housing  1054 , including a baseplate  1054   b  and a cover  1054   a,  is mounted to an end of an upper conveyor support bar  1056 . The base plate  1054   b  of each side of the machine is fastened to a linear actuator, such as a pneumatic cylinder  1055   a  and  1055   b  respectively. The cylinders  1055   a,    1055   b  are connected together by the support bar  1056 . Each cylinder slides on a fixed vertical rod  1057   a,    1057   b  respectively. Thus, controlled air to the cylinders  1055   a,    1055   b  can be used to uniformly raise or lower the near side housing  1054  and the far side housing  1054  uniformly. 
         [0072]    A spindle  1060  extends through the motor housing  1054 , through a sleeve  1064 , through a coupling  1065 , through the tubular stub axle  1016 , through the central bore  1014 , through the tubular stub axle  1018 , through the tubular stub axle  1046 , and partly into the bore  1044 . The spindle  1060  has a hexagonal cross-section base region  1070 , a round cross-section intermediate region  1072 , and a hexagonal cross-section distal region  1074 . The hexagonal cross-section base region  1070  is locked for rotation with a surrounding sleeve  1071  to rotate therewith. 
         [0073]    The intermediate region  1072  is sized to pass through the sleeve  1064 , through the tubular stub axle  1016 , through the central bore  1014 , and through the tubular stub axle  1018  to be freely rotatable therein. The distal region  1074  is configured to closely fit into a hexagonal shaped central channel  1078  of the tubular stub axle  1046  to be rotationally fixed with the tubular stub axle  1046  and the drive roller  1038 . 
         [0074]    The sleeve  1064  includes a hexagonal perimeter end  1064   a  that engages a hexagonal opening  1065   a  of the coupling  1065 . The coupling  1065  includes an opposite hexagonal opening  1065   a  that engages a hexagonal perimeter end  1016   a  of the tubular stub axle  1016 . The coupling  1065  couples the sleeve  1064  and the stub axle  1016  for mutual rotation such that the sleeve  1064  and the drive roller  1010  are locked for rotation together, i.e., turning of the sleeve  1064  turns the drive roller  1010 . 
         [0075]    Within the motor housing  1054  are two servomotors  1090 ,  1092  mounted to the housing by fasteners. As shown in  FIGS. 4 and 6 , the servomotor  1090  has a vertically oriented output shaft  1096  that rotates about a vertical axis connected to a worm gear  1098  that is enmesh with and drives a drive gear  1100  that rotates about a horizontal axis. The drive gear  1100  drives the sleeve  1071  that drives the region  1070  of the spindle to rotate the spindle  1060 . Rotation of the spindle  1060  rotates the drive roller  1038  via the hexagonal cross-section distal end region  1074 . 
         [0076]    Adjacent to the servomotor  1090  is the servomotor  1092 . The servomotor  1092  is configured substantially identically with the servomotor  1090  except the worm gear  1098 , as shown in schematic form in  FIG. 5 , of the servomotor  1092  drives a drive gear  1100  that drives the sleeve  1064  to rotate. The sleeve  1064  rotates independently of the round cross-section region  1072  of the spindle  1060 , and drives a stub axle  1016  to rotate, which rotates the drive roller  1010 . 
         [0077]    The sleeves  1071  and  1064  are journaled for rotation by bearings. The drive gears  1100 ,  1100  are fastened to the respective sleeve  1071 ,  1064  using fasteners  1116 . 
         [0078]    Each conveyor belt  1002 ,  1004 ,  1008  is wrapped around the respective drive roller and a front idle rollers  1134 ,  1135 ,  1136  that is supported by respective side frames  1131 ,  1132 . 
         [0079]    Also, as shown in  FIGS. 7 ,  7 E, and  13 A- 13 C, the underside of the support bar  1056  carries pneumatic cylinders  1130 . Each pneumatic cylinder  1130  is supplied with a preselected air pressure to extend a piston rod  1013 ,  1015 ,  1017  to press down on pressers  1003 ,  1005 ,  1007  to lightly press down on a top of the product below, clamping the food article between the pressers  1003 ,  1005 ,  1007  and the belts  1002 ,  1004 ,  1008 . Piston rods  1013   a,    1015   a,    1017   a  in their extended position and pressers, in their depressed position  1003   a,    1005   b,    1007   a  are illustrated in  FIG. 7E . The conveyor belts  1002 ,  1004 ,  1008  drive the food articles through corresponding orifices in the slicing block and into the slicing plane. 
         [0080]      FIG. 7F  illustrates an alternate embodiment of the lower conveyor. The same reference signs indicate similar parts as described above. In the embodiment illustrated in  FIG. 7F , the lower conveyor  992   a,    994   a,    998   a  is pivotable about an axis A parallel to the central axis of a drive roller  1010   a.  Each conveyor belt  1002 ,  1004 ,  1008  is wrapped around the respective drive roller and a front idle rollers  1134 ,  1135 ,  1136  that is supported by respective side frames  1131 ,  1132 . Side frames  1131 ,  1132  may be connected to a transverse bottom surface or bar  1133  which provides at least a region of contact for at least one piston rod  1137  disposed below the top surface of the conveyors. A support bar  1058  below the lower conveyors carries one or more pneumatic cylinders  1139 , such as three pneumatic cylinders, supplied with a pre-selected air pressure, each of which extends a piston rod to pivot the lower conveyor about the pivot axis. Extension of the piston rods tilts the lower conveying surface towards presser plates  1003 ,  1005 ,  1007  to provide pressure in grasping the food product between the presser plates and the lower conveyor  992   a,    994   a,    998   a.  The tilt or pivot of the lower conveyor can be adjustable over a variable angular distance, such as 7 degrees. The lower conveyor  992   b,    994   b,    998   b  is illustrated in is lowered position. 
         [0081]    The drive roller  1010   a  can be driven by a hexagonal shaft  1011  connected to a motor (not shown in  FIG. 7F ). Hexagonal shaft  1011  comprises a circular channel  1014  which allows the hexagonal shaft, and accordingly the drive roller  1010   a,  to pivot about the axis A of the circular channel  1014 . A combination of multiple concentric hexagonal shafts with a circular channel for coupling about a circular shaft can be used to drive adjacent lower conveyors. 
         [0082]    Side frames  1131 ,  1132  comprises an opening  1021  in the shape of an arc, which accommodates the cross-sectional dimensions of a support or alignment bar  1019 , which can extend across the span of lower conveyors and intersect the side frames of each lower conveyor. The angular angle of the arc corresponds to the degree of angular movement of the lower conveyor. 
       Feed Paths 
       [0083]    The illustrated apparatus provides three feed paths, although any number of paths are encompassed by the invention. The near side feed path is defined by the gripper  394  driven by the belt  802  which feeds the near side food article into the space between the conveyor belt  998  and presser  107 . The middle feed path is defined by the gripper  394  driven by the belt  804  which feeds the middle food article into the space between the conveyor  994  and the presser  105 . the far side fed path is defined by the gripper  394  driven by the belt  806  which feeds the far side food article into the space between the conveyor  992  and the presser  103 . 
       Food Article Loading Apparatus 
       [0084]    As illustrated in  FIG. 1 , the automatic food article loading apparatus  108  includes a lift tray assembly  220 , and a lift tray positioning apparatus  228 . The lift tray assembly  220  receives food articles to-be-sliced. The tray positioning apparatus  228  pivots the tray assembly  220  to be parallel with, and below the food article feed apparatus  120  in a staging position. 
       Lift Tray Positioning Apparatus 
       [0085]      FIGS. 8-10  illustrate the food article lift tray assembly  220  includes a frame  290  that supports movable food article support tray  302 . The tray  302  is removed in  FIG. 10 . The frame  290  includes an end plate  291 . Food article are loaded onto the tray  302  until they abut the end plate  291 . The tray  302  includes four spaced-apart guard rails  303  that define three lanes corresponding to three feed paths for the slicing machine. 
         [0086]    As illustrated in  FIGS. 1 and 10 , the frame  290  is connected by a rear connection  330  and a front connection  332  to a lever  336 . The lever  336  is pivotally mounted onto the shaft  193 . 
         [0087]    The mechanism  228  includes a pneumatic or hydraulic, extendable cylinder  350  that has a rod  352  pivotally connected to the lever  336  or the frame  290  at a connection  353 , and a cylinder body  354  pivotally connected to the floor  140  at a connection  356 . Extension or retraction of the rod  352  pivots the lever  336  and frame  290  about the connection  342 . 
       Lift Tray Assembly 
       [0088]    As shown in  FIG. 10 , an inner frame  375  supports the tray  302  within the frame  290 . The inner frame  375  is movable vertically with respect to the frame  290 . The inner frame  375  is liftable by pneumatic cylinders  380  to an elevated position above the staging position below the feed paths to lift the food articles to be in the food paths and to be gripped by the grippers The cylinders  380  have rods connected to cross members of the frame  375  and cylinder bodies fastened to cross members of the frame  290 . In the elevated position, the tray top surface  302   a  is just above the top of the end plate  291  so the food articles can be moved longitudinally off the tray  302 . 
       Food Article Gate 
       [0089]    As illustrated in  FIG. 13A-13D  a food article gate  2020  is operable to be used as a gate, to be used as a floor for supporting the food article, and to be used as a trap door to drop a food article remainder end through the trap door against a baffle  2022  and onto a scrap conveyor  122 . The scrap conveyor  122  is also located below the cutting plane to dispose of shaving scrap caused by the blade on the food article during idle dwell periods. 
         [0090]    The scrap conveyor  122  can be continuously circulated by use of a drum motor on one of the rollers. The conveyor delivers scrap to a discharge chute  2030  ( FIGS. 13D and 9 ) where the scrap can be collected in a bucket or other means. 
         [0091]    The gate  2020  can be operated to be positioned according to  FIG. 13A-13C  by a linear actuator such as a servomotor actuator or a pneumatic cylinder, as shown in  FIGS. 11 and 12 . A servomotor actuator  2036  is pivotally connected to the cabinet  855  at a pivot point  2038  and has an actuator rod  2040  pivotally connected to a lever  2042  which is fixedly connected to an axle rod  2044 . The axle rod  2044  sealing penetrates through the cabinet wall as shown in  FIG. 11 . The axle rod  2044  is fixed to the gate  2020 . the axle rod  2044  is journalled at an opposite end to a bracket  2048 . By extension or retraction of the rod  2044  the gate  2020  can be selectively pivoted. By machine control. 
       Laser Detectors 
       [0092]    A separate food article end detector is used for each of the three illustrated food paths. Preferably, the detectors are laser distance sensors  2002 ,  2004 ,  2006 . Once the food articles are pivoted by the apparatus  228  to the staging position below the feed paths, the sensors  2002 ,  2004 ,  2006  sense the ends of each food article in the three lanes on the tray  302 , and communicate that information to the machine control. The machine control uses this information to control the servomotors  850  to control the positioning of the grippers to the ends of each food article and also controls the actuation of each gripper. By knowing the exact end of the food article the grippers know when to be activated to seize the food article. 
       Slicing Head Section 
       [0093]    The slicing head section is as described in WO 2010/011237, herein incorporated by reference. 
         [0094]    The slicing block with orifices is also as described in WO 2010/011237, herein incorporated by reference. 
         [0095]    The jump conveyor can also be configured as described in U.S. Ser. No. 11/449,574 filed Jun. 8, 2006 or WO 2010/011237, herein incorporated by reference. 
       Laser Safety Guard System 
       [0096]    The laser safety guard system  123  is illustrated in  FIGS. 1 and 8 . The system comprises a central sensor  123  that projects a horizontal fan beam approximately  360  degrees or as much of an angle as needed. If an obstruction is sensed, such as an operator&#39;s arm, one or more machine operations are halted by the machine control. The machine operations, such as the lift tray positioning apparatus, may be halted by machine controls when an obstruction in the fan beam is sensed. Other operations such as the slicing movement of the slicing blade, or the food article feeding apparatus, may also be halted with the laser safety guard system. 
         [0097]    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.