Abstract:
A knockout drive system for a food patty molding machine includes an electric motor; a rotary-to-linear motion converting apparatus operatively connected to the electric motor; and at least one knockout member operatively connected between the rotary-to-linear motion converting apparatus and the knockout plungers, to reciprocate the knockout plungers. The mold plate and knockout plungers are not mechanically linked to be driven together but are independently driven. The electric motor of the knockout drive system is a servo driven motor wherein the speed, acceleration, deceleration and dwell periods of the knockout plungers can be precisely controlled to be synchronized with the mold plate movements and positions, and for the type of food product, the output rate and the shape of the patties.

Description:
[0001]     This application claims the benefit of U.S. provisional application Ser. No. 60/503,354, filed Sep. 16, 2003, and U.S. provisional application Ser. No. 60/515,585, filed Oct. 29, 2003. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     Use of pre-processed foods, both in homes and in restaurants, has created a demand for high-capacity automated food processing equipment. That demand is particularly evident with respect to hamburgers, molded steaks, fish cakes, and other molded food patties.  
         [0003]     Food processors utilize high-speed molding machines, such as FORMAX F-6, F-12, F-19, F-26 or F-400 reciprocating mold plate forming machines, available from Formax, Inc. of Mokena, Ill., U.S.A., for supplying patties to the fast food industry. Prior known high-speed molding machines are also described for example in U.S. Pat. Nos. 3,887,964; 4,372,008; 4,356,595; 4,821,376; and 4,996,743 herein incorporated by reference.  
         [0004]     Although heretofore known FORMAX patty-molding machines have achieved commercial success and wide industry acceptance, the present inventors have recognized that needs exist for a forming machine having increased energy efficiency, and a smoother and quieter patty-forming machine operation. The present inventors have recognized that needs exist for an enhanced controllability and ability to tune a patty-forming machine for particular food materials to be processed, for an enhanced effectiveness of a patty-forming machine in producing uniform patties. The present inventors have recognized the needs exist for an enhanced convenience for cleaning and maintenance of a patty-forming machine, and for an increased durability and an increased duration of maintenance free operation.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention provides an improved knockout drive system for a food patty molding machine capable of producing uniform molded food patties at a high rate of production. The invention relates to reciprocating mold plate food patty molding machines wherein cavities in a reciprocating mold plate are filled when the mold plate is in or around a fill position, and the cavities are emptied by reciprocating knockout plungers when the mold plate is in a patty discharge position, to form patties.  
         [0006]     The knockout drive system of the invention includes an electric motor; a rotary-to-linear motion converting apparatus operatively connected to the electric motor; and at least one knockout member operatively connected between the rotary-to-linear motion converting apparatus and the knockout plungers, to reciprocate the knockout plungers.  
         [0007]     Preferably, the electric motor of the knockout drive system is a precise position controlled motor, such as a servo driven motor, wherein the speed, acceleration, deceleration and dwell periods of the knockout plungers can be precisely controlled to be synchronized with the mold plate movements and positions, and for the type of food product, the output rate and the shape of the patties.  
         [0008]     According to one aspect of this system, the mold plate and knockout plungers are not mechanically linked to be driven together but are independently driven. Also, the reciprocating mold plate is preferably also driven by a separate, precise position controlled motor, such as a servomotor. More sophisticated mold plate and knockout plunger movements and sequencing can thus be programmed into, and synchronized by, the controller depending on the characteristics of the food product, the output rate, and the patty shape.  
         [0009]     The invention also provides a knockout plunger arrangement that is easily adjusted in position to reduce overhang forces caused by the driving element being at a distance from the knockout plungers. According to the preferred embodiment of the invention, because the knockout plungers are driven by an independent motor drive, the motor can be shifted forwardly to reduce this overhang. This feature is particularly advantageous when multiple rows of knockout plungers are provided to discharge multiple rows of patties.  
         [0010]     The invention provides an improved high-speed food patty molding machine that is subject to minimal wear in operation, and that requires minimal maintenance. The invention also provides an improved high-speed patty molding machine that is quiet in operation. The invention also provides an improved patty molding machine that has and enhanced energy efficiency. The invention also provides an improved high-speed food patty molding machine that is simple and cost effectively manufactured and assembled, and that can be readily disassembled for cleaning of the machine.  
         [0011]     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, and from the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a perspective view of a patty-forming machine of the present invention;  
         [0013]      FIG. 1A  is an elevational view of the patty-forming machine of  FIG. 1 ;  
         [0014]      FIG. 2  is a longitudinal sectional view of the patty-forming machine of  FIG. 1 , with some panels and/or components removed for clarity;  
         [0015]      FIG. 3  is a sectional view taken generally along line  3 - 3  of  FIG. 2 , with some panels and/or components removed for clarity;  
         [0016]      FIG. 4  is a sectional view taken generally along line  4 - 4  of  FIG. 2 , with some panels and/or components removed for clarity;  
         [0017]      FIG. 5  is a sectional view taken generally along line  5 - 5  of  FIG. 2 , with some panels and/or components removed for clarity;  
         [0018]      FIG. 6  is a sectional view taken generally along line  6 - 6  of  FIG. 2 , with some panels and/or components removed for clarity;  
         [0019]      FIG. 7  is a sectional view taken generally along line  7 - 7  of  FIG. 2 , with some panels and/or components removed for clarity;  
         [0020]      FIG. 8  is a sectional view taken generally along line  8 - 8  of  FIG. 2 , with some panels and/or components removed for clarity;  
         [0021]      FIG. 9A  is an enlarged fragmentary sectional view taken from  FIG. 2 , showing the machine configuration with the mold plate in a cavity fill position;  
         [0022]      FIG. 9B  is an enlarged fragmentary sectional view taken from  FIG. 2 , showing the machine configuration with the mold plate in a patty discharge position;  
         [0023]      FIG. 10  is a fragmentary sectional view taken generally along line  10 - 10  of  FIG. 2 , with some panels and/or components removed for clarity;  
         [0024]      FIG. 10A  is a fragmentary sectional view taken from  FIG. 10 , with some components removed for clarity;  
         [0025]      FIG. 11  is a fragmentary sectional view taken generally along line  11 - 11  of  FIG. 10 , with some panels and/or components removed for clarity;  
         [0026]      FIG. 12  is a schematic control diagram of the machine of the present invention;  
         [0027]      FIG. 13   a  is a fragmentary sectional view taken generally along line  13 A- 13 A of  FIG. 10A  showing the knock out apparatus in a rear position, with some panels and/or components removed for clarity;  
         [0028]      FIG. 13B  is a sectional view similar to  FIG. 13A  showing the knockout apparatus in a forward position; and  
         [0029]      FIG. 14  is enlarged, fragmentary sectional view taken generally along line  14 - 14  of  FIG. 6 , with some components and/or panels removed for clarity.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]     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.  
         [0000]     General Description of the Apparatus  
         [0031]     The high-speed food patty molding machine  20  illustrated in the figures comprises a preferred embodiment of the invention. The complete machine is described in U.S. Ser. No. ______, identified as attorney docket number 2188P0390US, filed on the same day as the present application, and herein incorporated by reference. This application also incorporates by reference U.S. Application Ser. No. 60/503,354, filed Sep. 16, 2003 and U.S. Provisional Application Ser. No. 60/515,585, filed Oct. 29, 2003.  
         [0032]     The molding machine  20  includes a machine base  21 , preferably mounted upon a plurality of feet  22 , rollers or wheels. The machine base  21  supports the operating mechanism for machine  20  and can contains hydraulic actuating systems, electrical actuating systems, and most of the machine controls. The machine  20  includes a supply  24  for supplying moldable food material, such as ground beef, fish, or the like, to the processing mechanisms of the machine.  
         [0033]     A control panel  19 , such as a touch screen control panel, is arranged on a forward end of the apparatus  20  and communicates with a machine controller  23 , shown in  FIG. 12 .  
         [0034]     As generally illustrated in  FIGS. 2-6 , supply means  24  comprises a large food material storage hopper  25  that opens into the intake of a food pump system  26 . The food pump system  26  includes at least two food pumps  61 ,  62 , described in detail hereinafter, that continuously, or intermittently under a pre-selected control scheme, pump food material, under pressure, into a manifold  27  flow-connected to a cyclically operated molding mechanism  28 .  
         [0035]     In the operation of machine  20 , a supply of ground beef or other moldable food material is deposited into hopper  25  from overhead. An automated refill device (not shown) can be used to refill the hopper when the supply of food product therein is depleted. The floor of hopper  25  is substantially defined by a conveyor belt  31  of a conveyor  30 . the conveyor belt has a top surface  31   a  for moving the food material longitudinally of the hopper  25  to a hopper forward end  25   a.    
         [0036]     The food material is moved by supply means  24  into the intake of plunger pumps  61 ,  62  of pumping system  26 . The pumps  61 ,  62  of system  26  operate in overlapping alteration to each other; and at any given time when machine  20  is in operation, at least one of the pumps is forcing food material under pressure into the intake of manifold  27 .  
         [0037]     The manifold  27  comprises a system for feeding the food material, still under relatively high pressure, into the molding mechanism  28 . Molding mechanism  28  operates on a cyclic basis, first sliding a multi-cavity mold plate  32  into a receiving position over manifold  27  ( FIG. 9A ) and then away from the manifold to a discharge position ( FIG. 9B ) aligned with a series of knockout plungers such as knockout cups  33 . When the mold plate  32  is at its discharge position, knockout cups  33  are driven downwardly as indicated by  33 A in  FIG. 2 , discharging hamburgers or other molded patties from machine  20 . The molded patties are deposited onto a conveyor  29  ( FIG. 1A ), to be transported away from the apparatus  20 .  
         [0000]     Food Supply System  
         [0038]     The food supply means  24  and associated hopper  25  are illustrated in  FIGS. 2-6 . As seen, the conveyor belt  31  spans completely across the bottom of hopper  25 , around an end of idler roller or pulley  35  and drive roller or pulley  36 , the lower portion of the belt being engaged by a tensioning roller  37 . In some cases the tensioning roller  37  may not be necessary, and can be eliminated. A drum motor (not visible) is provided within the drive roller  36  for rotating the drive roller.  
         [0039]     The forward end  25   a  of hopper  25  communicates with a vertical pump  38  having an outlet  39  at least partly open into a pump intake manifold chamber  41 . A vertically oriented frame  42  extends above hopper  25  adjacent the right-hand side of the outlet  39 . A motor housing  40  is mounted on top of the frame  42 . A support plate  43  is affixed to the upper portion of frame  42  extending over the outlet  39  in hopper  25 . The frame comprises four vertical tie rods  44   a  surrounded by spacers  44   b  ( FIG. 5 ).  
         [0040]     As shown in  FIG. 5 , the vertical pump  38  comprises two feed screw motors  45 ,  46  that drive feed screws  51 ,  52 . The two electrical feed screw motors  45 ,  46  are mounted upon the support plate  43  within a motor housing  40 . Motor  45  drives the feed screw  51  that extends partly through opening  39  in alignment with a pump plunger  66  of the pump  61 . Motor  46  drives the feed screw  52  located at the opposite side of hopper  25  from feed screw  51 , and aligned with another pump plunger  68  of the pump  62 .  
         [0041]     A level sensing mechanism  53  is located at the outlet end of hopper  25  comprising an elongated sensing element  54 . As the moldable food material is moved forwardly in the hopper  25 , it may accumulate to a level in which it engages the sensing element  54 . When this occurs, a signal is generated to interrupt the drive for the roller  36  of conveyor  31 . In this manner the accumulation of food material at the forward end  25   a  of hopper  25  is maintained at an advantageous level.  
         [0042]     When machine  20  is in operation, the feed screw motor  45  is energized whenever plunger  66  is withdrawn to the position shown in  FIG. 2 , so that feed screw  51  supplies meat from hopper  25  downwardly through outlet  39  into one side of the intake  41  of the food pumping system  26 . Similarly, motor  46  actuates the feed screws  52  to feed meat to the other side of intake  41  whenever plunger  68  of the pump  62  is withdrawn. In each instance, the feed screw motors  45 ,  46  are timed to shut off shortly after the plunger is fully retracted, avoiding excessive agitation of the meat. As the supply of food material in the outlet  39  is depleted, the conveyor belt  31  continuously moves food forwardly in the hopper and into position to be engaged by the feed screws  51 ,  52 . If the level of meat at the outlet  39  becomes excessive, conveyor  30  is stopped, as described above, until the supply at the hopper outlet is again depleted.  
         [0043]     The wall of the outlet  39  immediately below conveyor drive rollers  36  comprises a belt wiper plate  57  that continuously engages the surface of the conveyor  31  to prevent leakage of the food material  38  from the hopper at this point.  
         [0000]     Food Pump System  
         [0044]     The food pump system  26  of molding machine  20  is best illustrated in  FIGS. 2 and 6 . Pump system  26  comprises the two reciprocating food pumps  61 ,  62  mounted on the machine base  21 . The first food pump  61  includes a hydraulic cylinder  64 . The piston (not shown) in cylinder  64  is connected to an elongated piston rod  67 ; the outer end of the elongated piston rod  67  is connected to the large plunger  66 . The plunger  66  is aligned with a first pump cavity  69  formed by a pump cavity enclosure or housing  71  that is divided into two pump chambers. The forward wall  74  of pump cavity  69  has a relatively narrow slot  73  that communicates with the pump manifold  27  as described more fully hereinafter.  
         [0045]     Preferably, the pump housing  71  and the valve manifold  27  are cast or formed as a one piece stainless steel part.  
         [0046]     The second food pump  62  is essentially similar in construction to pump  61  and comprises a hydraulic cylinder  84 . Cylinder  84  has an elongated piston rod  87  connected to the large plunger  68  that is aligned with a second pump cavity  89  in housing  71 . The forward wall  94  of pump cavity  89  includes a narrow elongated slot  93  communicating with manifold  27 .  
         [0047]     Advantageously, the plungers  66 ,  68  and pump cavities  69 ,  89  have round cross sections for ease of manufacturing and cleaning.  
         [0048]     In operation, the first pump  61  pumps the moldable food material into manifold  27  and the second pump  62  receives a supply of the moldable food material for a subsequent pumping operation. Pump  61  begins its pumping stroke, and compresses food product in pump cavity  69 , forcing the moldable food material through slot  73  into manifold  27 . As operation of molding machine  20  continues, pump  61  advances plunger  66  to compensate for the removal of food material through manifold  27 . The pump can maintain a constant pressure on the food material in the chamber  69  during the molding cycle, or preferably can provide a pre-selected pressure profile over the molding cycle such as described in U.S. Pat. No. 4,356,595, incorporated herein by reference, or as utilized in currently available FORMAX machines.  
         [0049]     When plunger  66  is near the end of its permitted range of travel, pump  62  is actuated to advance plunger  68  through pump cavity  89 , compressing the food material in the second pump cavity in preparation for feeding the food material from the cavity into manifold  27 .  
         [0050]     When the food in the second pump cavity  89  is under adequate pressure, the input to manifold  27  is modified so that subsequent feeding of food product to the manifold is effected from the second pump cavity  89  with continuing advancement of plunger  68  of the second pump  62 . After the manifold intake has been changed over, pump  61  is actuated to withdraw plunger  66  from cavity  69 .  
         [0051]     Thereafter, when plunger  68  is near the end of its pressure stroke into pump cavity  89 , the changeover process described immediately above is reversed. Pump  61  begins its compression stroke, manifold  27  is changed over for intake from pump  61 , and pump  62  subsequently retracts plunger  68  back to the supply position to allow a refill of pump cavity  89 . This overlapping alternating operation of the two pumps  61 ,  62  continues as long as molding machine  20  is in operation.  
         [0052]     The valve manifold  27 , shown in  FIGS. 2 and 6 , holds a manifold valve cylinder or tube valve  101  fit into an opening  102  in housing  71  immediately beyond the pump cavity walls  74  and  94 .  
         [0053]     According to the illustrated embodiment, valve cylinder  101  includes two longitudinally displaced intake slots  107  and  108  alignable with the outlet slots  73  and  93 , respectively, in the pump cavity walls  74  and  94 . Slots  107  and  108  are angularly displaced from each other to preclude simultaneous communication between the manifold and both pump cavities  69  and  89 . Cylinder  101  also includes an elongated outlet slot  109 . The valve cylinder outlet slot  109  is generally aligned with a slot  111  (see  FIG. 9A ) in housing  71  that constitutes a feed passage for molding mechanism  28 .  
         [0054]     One end wall of valve cylinder  101  includes an externally projecting base end  103  that is connected to a drive linkage  104 , which is in turn connected to the end of the piston rod  105  of a hydraulic actuator cylinder  106  ( FIG. 2 ). Proximity sensors  106   a ,  106   b  communicate the rotary position of the valve cylinder to the machine controller  23 .  
         [0055]     When the pump  61  is supplying food material under pressure to molding mechanism  28 , actuator cylinder  106  has retracted piston rod  105  to the inner limit of its travel, angularly orienting the manifold valve cylinder  101 . With cylinder  101  in this position, its intake slot  107  is aligned with the outlet slot  73  from pump cavity  69  so that food material is forced under pressure from cavity  69  through the interior of valve cylinder  101  and out of the valve cylinder outlet slot  109  through slot  111  to the molding mechanism  27 . On the other hand, the second intake slot  108  of valve cylinder  101  is displaced from the outlet slot  93  for the second pump cavity  89 . Consequently, the food material forced into the interior of valve cylinder  101  from pump cavity  69  cannot flow back into the other pump cavity  89 .  
         [0056]     The valve cylinder  101  and corresponding slots or openings can alternately be as described in U.S. Provisional Application 60/571,368, filed May 14, 2004, or U.S. Ser. No. ______, filed on the same day as the present invention and identified by attorney docket number 2188P0381US, both herein incorporated by reference. According to these disclosures, rather than a single outlet  109 , two rows of progressively sized outlets, smallest closest to the active pump, are alternately opened to plural openings that replace the single opening  111 .  
         [0000]     Molding Mechanism  
         [0057]     As best illustrated in  FIG. 9A , the upper surface of the housing  71  that encloses the pump cavities  69  and  89  and the manifold  27  carries a support plate or wear plate  121  and a fill plate  121   a  that forms a flat, smooth mold plate support surface. The mold support plate  121  and the fill plate  121   a  may be fabricated as two plates as shown or a single plate bolted to or otherwise fixedly mounted upon housing  71 . The fill plate  121   a  includes apertures or slots that form the upper portion of the manifold outlet passage  111 . In the apparatus illustrated, a multi fill orifice type fill plate  121   a  is utilized. A simple slotted fill plate is also encompassed by the invention.  
         [0058]     Mold plate  32  is supported upon plates  121 ,  121   a . Mold plate  32  includes a plurality of individual mold cavities  126  extending across the width of the mold plate and alignable with the manifold outlet passageway  111 . Although a single row of cavities is shown, it is also encompassed by the invention to provide plural rows of cavities, stacked in aligned columns or in staggered columns. A cover plate  122  is disposed immediately above mold plate  32 , closing off the top of each of the mold cavities  126 . A mold cover casting or housing  123  is mounted upon cover plate  122 . The spacing between cover plate  122  and support plate  121  is maintained equal to the thickness of mold plate  32  by support spacers  124  mounted upon support plate  121 . Cover plate  122  rests upon spacers  124  when the molding mechanism is assembled for operation. Cover plate  122  and mold cover casting  123  are held in place by six mounting bolts, or nuts tightened on studs,  125 .  
         [0059]     The cover plate  122  can be configured as a breather plate as part of a molding mechanism air-and-fines removal system, such as described in U.S. Ser. No. ______, identified as attorney docket number 2188P0370US, and filed on the same day as the present application, and herein incorporated by reference.  
         [0060]     As best illustrated in  FIGS. 3 and 6 , mold plate  32  is connected to drive rods  128  that extend alongside housing  71  and are connected at one end to a transverse bar  129 . The other end of each drive rod  128  is pivotally connected to a connecting link  131  via a coupling plate  131   a  and a pivot connection  131   c , shown in  FIG. 2 . The pivot connection  131   c  can include a bearing (not visible in the figures) surrounding a pin within an apertured end of the connecting link  131 . The pin includes a cap, or carries a threaded nut, on each opposite end to secure the crank arm to the coupling plate  131   a.    
         [0061]     Each drive rod  128  is carried within a guide tube  132  that is fixed between a wall  134  and a front bearing housing  133 . The connecting links  131  are each pivotally connected to a crank arm  142  via a pin  141  that is journaled by a bearing  141   a  that is fit within an end portion of the connecting link  131 . The pin crank arm  142  is fixed to, and rotates with, a circular guard plate  135 . The pin  141  has a cap, or carries a threaded nut, on each opposite end that axially fixes the connecting link  131  to the crank arm  142  and the circular guard plate  135 . The connecting link  131  also includes a threaded portion  131   b  to finely adjust the connecting link length.  
         [0062]     The crank arms  142  are each driven by a right angle gear box  136  via a “T” gear box  137  having one input that is driven by a precise position controlled motor  138  and two outputs to the gearboxes  136 . The “T” gear box  137  and the right angle gear boxes  136  are configured such that the crank arms  142  rotate in opposite directions at the same rotary speed.  
         [0063]     The precise position controlled motor can be a 6-7.5 HP totally enclosed fan cooled servo motor. The servo motor is provided with two modules: a power amplifier that drives the servo motor, and a servo controller that communicates precise position information to the machine controller  23 .  
         [0064]     The controller  23  and the servo motor  138  are preferably configured such that the servo motor rotates in an opposite rotary direction every cycle, i.e., clockwise during one cycle, counterclockwise the next cycle, clockwise the next cycle, etc.  
         [0065]     A bearing housing  143  is supported on each gearbox  136  and includes a rotary bearing  143   a  therein to journal an output shaft  136   a  of the gear box  136 . The output shaft  136   a  is fixed to the crank arm  142  by a clamp arrangement formed by legs of the crank arm  142  that surround the output shaft and have fasteners that draw the legs together to clamp the output shaft between the legs (not shown), and a longitudinal key (not shown) fit into a keyway  136   b  on the output shaft and a corresponding keyway in the crank arm  142  (not shown).  
         [0066]     A tie bar  139  is connected between the rods  128  to ensure a parallel reciprocation of the rods  128 . As the crank arms  142  rotate in opposite rotational directions, the outward centrifugal force caused by the rotation of the crank arms  142  and the eccentric weight of the attached links  131  cancels, and separation force is taken up by tension in the tie bar  139 .  
         [0067]     One circular guard plate  135  is fastened on top of each crank arm  142 . The pin  141  can act as a shear pin. If the mold plate should strike a hard obstruction, the shear pin can shear by force of the crank arm  142 . The guard plate  135  prevents an end of the link  131  from dropping into the path of the crank arm  142 .  
         [0068]      FIG. 14  illustrates a proximity sensor  144  in communication with the machine control. A target  144   a  is clamped onto an extension  136   d  of the rotating shaft  136   a . The proximity sensor  144  communicates to the controller  23  that the crank arm  142  is at a particular rotary position corresponding to the mold plate  32  being at a pre-selected position. Preferably, the proximity sensor  144  can be arranged to signal to the controller that the crank arm  142  is in the most forward position, corresponding to the mold plate  32  being in the knockout position. The signal confirms to the controller that the knockout cups  33  can be safely lowered to discharge patties, without interfering with the mold plate  32 .  
         [0069]     During a molding operation, the molding mechanism  28  is assembled as shown in  FIGS. 2 and 9 A, with cover plate  122  tightly clamped onto spacers  124 .  
         [0070]     In each cycle of operation, knockout cups  33  are first withdrawn to the elevated position as shown in  FIG. 9B . The drive for mold plate  32  then slides the mold plate from the full extended position to the mold filling position illustrated in  FIGS. 2 and 9 A, with the mold cavities  126  aligned with passageway  111 .  
         [0071]     During most of each cycle of operation of mold plate  32 , the knockout mechanism remains in the elevated position, shown in  FIGS. 9A, 9B ,  10  and  11 , with knockout cups  33  clear of mold plate  32 . When mold plate  32  reaches its extended discharge position as shown in  FIG. 9B , the knockout cups  33  are driven downward to discharge the patties from the mold cavities.  
         [0072]     The discharged patties may be picked up by the conveyor  29  or may be accumulated in a stacker. If desired, the discharged patties may be interleaved with paper, by an appropriate paper interleaving device. Such a device is disclosed in U.S. Pat. No. 3,952,478, or U.S. Ser. No. 60/540,022, filed on Jan. 27, 2004, both incorporated herein by reference. In fact, machine  20  may be used with a wide variety of secondary equipment, including steak folders, bird rollers, and other such equipment.  
         [0073]     By using a servo motor to drive the mold plate, the mold plate motion can be precisely controlled. The motion can have a fully programmable dwell, fill time, and advance and retract speeds.  
         [0000]     Knockout System  
         [0074]     Molding mechanism  28  further comprises a knockout apparatus  140  shown in  FIGS. 2, 9A ,  10 - 11 ,  13 A and  13 B. The knockout apparatus comprises the knockout plungers or cups  33 , which are fixed to a carrier bar  145 . Knockout cups  33  are coordinated in number and size to the mold cavities  126  in the mold plate  32 . One knockout cup  33  is aligned with each mold cavity  126 . The mold cavity size is somewhat greater than the size of an individual knockout cup.  
         [0075]     The knockout apparatus  140  is configured to drive the carrier bar  145  in timed vertical reciprocation.  
         [0076]      FIGS. 10-11 ,  13 A and  13 B illustrate the knockout apparatus  140  in more detail. The carrier bar  145  is fastened to knockout support brackets  146   a ,  146   b . The knockout support brackets  146   a ,  146   b  are carried by two knockout rods  147 . Each knockout rod  147  is disposed within a wall of a knockout housing  148  and is connected to a knockout beam  149 .  
         [0077]     The knockout beam  149  is pivotally mounted to a crank rod  151  that is pivotally connected to a fastener pin  156  that is eccentrically connected to a crank hub  155  that is driven by a motor  157 .  
         [0078]     The motor is preferably a precise position controlled motor, such as a servo motor. An exemplary servomotor for this application is a 3000 RPM, 2.6 kW servo motor provided with a brake. The servo motor is provided with two modules: a power amplifier that drives the servo motor, and a servo controller that communicates precise position information to the machine controller  23 .  
         [0079]     The controller  23  and the motor  157  are preferably configured such that the motor rotates in an opposite direction every cycle, i.e., clockwise during one cycle, counterclockwise the next cycle, clockwise the next cycle, etc.  
         [0080]     A heating element  160  surrounds, and is slightly elevated from the knockout carrier bar  145 . A reflector  161  is mounted above the heating element  160 . The heating element heats the knock out cups to a pre-selected temperature, which assists in preventing food product from sticking to the knock out cups.  
         [0081]     In  FIGS. 10 and 11 , the crank hub  155  is rotated into a position wherein the crank rod  151  is vertically oriented and the knockout beam  149  is lifted to its maximum elevation. The knockout rods are fastened to the knockout beam  149  by fasteners  152 . The knockout support brackets  146   a ,  146   b  are in turn fastened to the knockout rods  147  by fasteners  153 . Each knockout cup  33  is fastened to the knockout carrier bar by a pair of fasteners  154   a  and spacers  154   b . An air flap or air check valve  33   a  can be provided within each cup to assist in dispensing of a meat patty from the cup  33 .  
         [0082]     As shown in  FIG. 11 , the motor  157  is supported by a bracket  170  from a frame member  172  that is mounted to the casting  123 . The bracket  170  includes one or more slotted holes, elongated in the longitudinal direction (not shown). One or more fasteners  173  penetrate each slotted hole and adjustably fix the motor  157  to the frame member. The motor  157  includes an output shaft  176  that is keyed to a base end of the crank hub  155 . The fastener pin  156  retains a roller bearing  178  thereon to provide a low friction rotary connection between an annular base end  151   a  of the crank rod  151  and the pin  156 .  
         [0083]     The crank rod  151  has an apertured end portion  179  on an upper distal end  151   b  opposite the base end  151   a . The apertured end portion  179  is held by a fastener pin assembly  180  through its aperture to a yoke  182 . The yoke  182  is fastened to the knockout beam  149  using fasteners. The fastener pin assembly  180  can include a roller or sleeve bearing (not shown) in like fashion as that used with the fastener pin  156  to provide a reduced friction pivot connection.  
         [0084]     The housing  148  is a substantially sealed housing that provides an oil bath. Preferably, the housing walls and floor is formed as a cast aluminum part. The crank hub  155 , the pin  156 , roller bearing  178 , the apertured end portion  179 , the fastener pin  180  and the yoke  182  are all contained within the oil bath having an oil level  183 . The limits of the oil bath are defined by a housing  184  having a front wall  185 , a rear wall  186 , side walls  187 ,  188 , a top wall  189  and a sleeve  190 . The sleeve  190  is a square tube that surrounds a substantial portion of the crank rod  151  and is sealed around its perimeter to the top wall  189  by a seal element  196   a . The sleeve  190  is connected to the beam  149  and penetrates below the top wall  189 . As the yoke  182  reciprocates vertically, the beam  149  and the sleeve  190  reciprocate vertically, the sleeve  190  maintaining a sealed integrity of the oil bath.  
         [0085]     The crank rod  151  includes side dished areas  151   a  that act to scoop and propel oil upward during rotation of the hub  155  to lubricate the pin  180  and surrounding areas.  
         [0086]     The knockout rods  147  are guided to reciprocate through the side walls  187 ,  188 , particularly, through upper and lower bearings  191   a ,  191   b . The rods  147  are sealed to the top wall by seals  192 . The bearings  191   a  can include an internal groove  193  that is in flow-communication with a lubricant supply through port  194 .  
         [0087]     A lubricant system  194   a  is provided to provide lubricant to the bearings  191   a ,  191   b . The system  194   a  includes a lubricant reservoir  194   b  that is filled with lubricant, such as oil, and connected to plant air  194   c  via an electronically controlled valve  194   d . The machine controller  23  periodically, according to a preset routine, actuates the valve  194   d  to propel some lubricant into the bearings  191   a . Lubricant can run down the knockout rod  147  into a dished top  191   c  of the lower bearings  191   b  to allow oil to penetrate between the knockout rods  147  and the lower bearings  191   b.    
         [0088]     An outer cover  195  is fastened and sealed around the side walls  187 ,  188  and front and rear walls  185 ,  186  by fasteners, spacers  196  and a seal  197 . Any lubricating oil that passes through the seal can be returned to the oil bath via dished out drain areas and drain ports through the top wall.  
         [0089]     The front wall  185  includes an oil level sight glass  185   a , a fill port  185   b  (shown dashed in  FIG. 10 ), a drain port  185   c  ( FIG. 11 ); and an access hole closed by a screw  185   d  ( FIG. 11 ).  
         [0090]     The crank hub  155  is journaled for rotation by two roller bearings  198 ,  199 . The roller bearings  198 ,  199  are supported by a collar assembly  200  bolted to the rear wall  186  and to the motor  157 .  
         [0091]     The knockout assembly is changeable to extend further forwardly to minimize knockout cup cantilever. This is accomplished by loosening the bracket  170  from the frame member  172  and sliding the motor and all the connected parts forward or rearward and replacing circular adapter plates for the knockout rods  147 .  
         [0092]     The housing  148  is fastened to a support plate  201  by fasteners  201   a . The support plate  201  is fastened to circular adapter plates  201   b  by fasteners  201   c . The circular adapter plates  201   b  are removably fit into circular holes  201   d  in the casting  123 . The circular adapter plates  201   b  include a bottom flange  201   e  which abuts the casting  123 . The circular adapter plates  201   b  surround the bearings  191   b  and associated bearing assemblies  191   c.    
         [0093]     As shown in  FIG. 10A , the left bracket  146   a  is fixedly connected to the left knockout rod  147  using the fastener  153  while the right bracket  146   b  is connected for a sliding connection. In this regard the right fastener  153  passes through an inverted T-nut  153   a  that passes through the bracket  146   b  and fits into a back up washer  153   b  that abuts the top side of the bracket  146   b . The bracket  146   b  includes an oversized opening in the lateral direction that allows the bracket  146   b  to shift laterally with respect to the T-nut and knockout rod  147 . This arrangement allows the bar  145  to expand and contract laterally with respect to the knockout rods  147 . When the knockout cups  33  are heated by the heating element  160 , the carrier bar  145  can become heated as well. Preferably, the carrier bar  145  is composed of aluminum which can expand to a significant degree. The sliding connection of the bracket  146   b  accommodates this thermal expansion.  
         [0094]     The knockout assembly is changeable to extend further forwardly to minimize knockout cup cantilever and stress in supporting members. This is accomplished by loosening the bracket  170  from the frame member  172  and sliding the motor  157  and the connected parts forward or rearward and replacing the circular adapter plates that guide the knockout rods  147 .  
         [0095]     As demonstrated in  FIGS. 13A and 13B , to change the longitudinal position of the knockout cups  33 , the support plate  201  is shifted longitudinally. Replacement circular adapter plates  201   bb  are fit into the casting  123  from below. The replacement circular adapter plates  201   bb  include different hole patterns for the knockout rods  147 , forwardly or rearwardly shifted, to accommodate the new position of the support plate  201 .  
         [0096]     A proximity sensor  202  is bolted to the outer cover  195 , and a target  203  is provided on the crank beam  149  to be sensed by the proximity sensor  202 . The proximity sensor  202  communicates to the controller  23  that the knockout cups are raised and the mold plate can be retracted without interfering with the knockout cups.  
         [0097]     The movement of the knockout cups is fully programmable for different motion profiles, including dwell, accelerations and extend and retract speeds. Such motion profiles may be useful depending on the properties of the food product to be discharged from the mold plate cavities. Because both the mold plate and the knockout cups can be driven by programmable, controlled servo motors, they can be flexibly sequenced without being restricted in motion by a common mechanical system.  
         [0098]     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.