Abstract:
A tube valve and manifold arrangement for switching food product pumps is incorporated into a molding machine. The tube valve includes either a central outlet or two selectable sets of progressively sized outlet openings, with the smallest outlet opening closest to the active plunger, and the largest opening furthest from the active plunger. The tube valve includes grooves or depressions formed on its outside surface. The depressions are oriented to be at least partially open to the pump cavity that is not actively filling. Grooves and bores are in fluid communication with the depressions to allow air trapped in the off line pump cavity to be expelled to the hopper. The tube valve mounting assembly includes inboard and outboard bushings located externally on opposite lateral sides of the valve manifold that are removably fastened to the outside of the valve manifold.

Description:
[0001]     The application claims the benefit of provisional application Ser. No. 60/571,368 filed May 14, 2004; 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 an even greater energy efficiency, an even greater durability and an even greater duration of maintenance free operation. The present inventors have recognized that needs exist for an enhanced effectiveness of a patty-forming machine in producing uniform patties, for an even greater output rate of patties from a patty-forming machine, and for an enhanced convenience for cleaning and maintenance of a patty-forming machine.  
       SUMMARY OF THE INVENTION  
       [0005]     The invention provides an improved tube valve arrangement for a reciprocating mold plate, patty-forming apparatus. In such a patty-forming apparatus, a food product delivery communicates food product into cavities of a reciprocating mold plate, via a food product valve manifold that houses a tube valve. Two food product pumps alternately deliver food product into inlets of the food product valve manifold via the tube valve, depending on the rotary position off the tube valve.  
         [0006]     According to one embodiment of the invention, the tube valve comprises an elongated cylinder having a first inlet port and a second inlet port, the inlet ports being offset rotationally around a circumference of the cylinder, and an outlet port located between the first inlet port and the second inlet port along a length of the cylinder. The outlet port is rotationally offset from the first and second inlet port. The outlet port comprises an open area substantially equivalent to the cumulative area of the first and second inlet port. The inlet ports are shaped in profile as ovals having a major dimension parallel to an axis of the cylinder, and the outlet port is shaped in profile as a rounded rectangle.  
         [0007]     According to an alternate embodiment of the invention, the tube valve comprises an elongated cylinder having a first inlet port and a second inlet port, the inlet ports being offset rotationally around a circumference of the cylinder. The cylinder includes two rows of progressively sized outlet ports, wherein each row corresponds to one of the first and second inlet ports such that food product flows from a selected one of the first and second inlet ports to its corresponding row of outlet ports. The progressively sized outlet ports are smallest axially-closest to the respective corresponding inlet port and largest axially-furthest from the corresponding inlet port. Each row can include two or more ports.  
         [0008]     According to this embodiment, the rows of outlet ports are rotationally offset from each other. Each row of the outlet ports comprises three oblong outlet ports. The inlet ports are shaped in profile as ovals having a major dimension parallel to an axis of the cylinder.  
         [0009]     According to another aspect of the invention, provision is made to express air from the pump chamber during initial compression of food product within the pump chamber that is not currently feeding food product to the mold plate. According to this aspect, the embodiment of the tube valve comprises an elongated cylinder that has a first inlet port and a second inlet port, the inlet ports being offset rotationally around a circumference of the cylinder, and at least one outlet port. A first depression is formed on an outside of the cylinder at least partially in registry with a first pump of the food pumps when a second pump of the food pumps is in registry with the second inlet port, and a second depression formed on an outside of the cylinder at least partially in registry with the second pump when the first pump is in registry with the first inlet port. The depressions are in fluid communication with a collection area outside of the pumps. Preferably the collection area is the food product hopper.  
         [0010]     As a further aspect of the invention, a plurality of breather holes are provided at each longitudinal end of the tube valve, through the tube valve wall. The breather holes are in communication with an inside of the tube valve and to an outside circumferential groove that is in communication with the depressions on the outside of the tube wall. Thus, air trapped at either end within the tube valve can be expressed back to the collection area.  
         [0011]     Accordingly, the preferred embodiment of the invention comprises a high-speed food patty molding machine having an inlet for receiving a moldable food material. The machine includes two food pumps, each pump including a pump cavity having an intake opening and an outlet opening, a plunger aligned with the cavity, and drives for moving the plunger between a retracted position clear of the intake opening in the cavity, and a pressure position in which the plunger is advanced inwardly of the cavity, beyond the intake opening, toward the outlet opening. Supply means are provided for supplying moldable food material to the intake opening of each pump cavity whenever the plunger for that pump is in its retracted position. A manifold connects the outlet openings of the two pump cavities to the inlet of the molding mechanism. Actuating means are provided to actuate the pumps in that at least one pump cavity always contains moldable food material under pressure.  
         [0012]     A molding mechanism comprises a reciprocating mold plate having one or more rows of mold cavities that are filled via the inlet of the molding mechanism.  
         [0013]     According to the invention, an improved tube valve and manifold arrangement for switching food product pumps is incorporated into the molding machine. According to one embodiment, the improved tube valve includes either a central outlet or two selectable sets of progressively sized outlet openings, with the smallest outlet opening closest to the active plunger, and the largest opening furthest from the active plunger, for a symmetrical, distribution of patty weights across a width of the mold plate. According to another aspect of the invention, the tube valve includes grooves or depressions that are formed on an outside surface thereof, and the depressions are oriented to be at least partially open to the pump cavity that is not actively filling, in effect is off line. The compression of food product against the outside surface of the tube at a pre-filling stage, allows air trapped in the off line pump cavity to be expelled through the grooves or depressions and from the depressions through bores that are in communication with grooves formed on a surface of the pump box. The grooves formed on the surface of the pump box are in communication with the hopper. Thus, before a filling cycle begins, that is, before the corresponding inlet port of the tube valve is opened to be in registry with the inactive pump, air trapped within food product can be expelled back to the hopper.  
         [0014]     The tube valve mounting assembly includes inboard and outboard bearings or bushings located externally on opposite lateral sides of the valve manifold that are removably fastened to the outside of the valve manifold. The bushings include an internal grease groove fed by a grease fitting. Thus, the bushings can be periodically greased. A first O-ring seal is provided inside the valve manifold which is sealed via the insertion of the lead end of the tube valve that is inserted into the manifold during assembly. A second O-ring seal is applied to a trailing end of the tube valve for sealing against an inside surface of the valve manifold.  
         [0015]     The present invention can provide an improved automated food patty molding machine capable of producing uniform molded food patties at a high rate of production. The invention can provide an improved pumping system for a high-speed food patty molding machine that consistently and continuously feeds hamburger or other molded food material to the molding mechanism of the machine at a high rate at substantially uniform pressure.  
         [0016]     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, maintenance and repair of the machine.  
         [0017]     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  
       [0018]      FIG. 1  is a perspective view of a patty-forming machine of the present invention;  
         [0019]      FIG. 1A  is an elevational view of the patty-forming machine of  FIG. 1 ;  
         [0020]      FIG. 2  is a longitudinal sectional view of the patty-forming machine of  FIG. 1 , with some components and/or panels not shown, or broken away, for clarity;  
         [0021]      FIG. 3  is a sectional view taken generally along line  3 - 3  of  FIG. 2 , with some components and/or panels not shown, or broken away, for clarity;  
         [0022]      FIG. 4  is a sectional view taken generally along line  4 - 4  of  FIG. 2 , with some components and/or panels not shown, or broken away, for clarity;  
         [0023]      FIG. 5  is an enlarged fragmentary sectional view taken from  FIG. 2 , with some components and/or panels not shown, or broken away, for clarity;  
         [0024]      FIG. 6  is a sectional view taken generally along line  6 - 6  of  FIG. 2 , with some components and/or panels not shown, or broken away, for clarity;  
         [0025]      FIG. 6A  is an elevational view of a tube valve of the present invention;  
         [0026]      FIG. 7  is a sectional view taken generally along line  7 - 7  of  FIG. 6A ;  
         [0027]      FIG. 8  is a sectional view taken generally along line  8 - 8  of  FIG. 6A ;  
         [0028]      FIG. 9  is a sectional view taken generally along line  9 - 9  of  FIG. 6A ;  
         [0029]      FIG. 10  is an elevational view taken generally along line  10 - 10  of  FIG. 9 ;  
         [0030]      FIG. 11  is an enlarged diagrammatic cross section of the tube valve of  FIG. 6A , showing the positions of and rotary expanse of inlet and outlet ports of the tube valve;  
         [0031]      FIG. 12  is an enlarged fragmentary sectional view taken generally along line  12 - 12  of  FIG. 4 , with some components and/or panels not shown, or broken away, for clarity;  
         [0032]      FIG. 13  is an enlarged fragmentary sectional view taken generally along line  44  of  FIG. 2 , with some components and/or panels not shown, or broken away, for clarity;  
         [0033]      FIG. 13A  is an elevational view of a bushing taken from  FIG. 12 ;  
         [0034]      FIG. 14  is a view taken generally of along line  14 - 14  of  FIG. 13 ;  
         [0035]      FIG. 14A  is a sectional view taken generally of along line  14 A- 14 A of  FIG. 14 ;  
         [0036]      FIG. 15  is an enlarged, fragmentary sectional view taken generally along line  15 - 15  of  FIG. 16  and showing a further aspect of the invention;  
         [0037]      FIG. 16  is a sectional view taken generally along line  16 - 16  of  FIG. 15 , with some components and/or panels not shown, or broken away, for clarity;  
         [0038]      FIG. 17  is a plan view of an alternate embodiment tube valve of the invention in a first rotary position;  
         [0039]      FIG. 18  is a plan view of an alternate embodiment tube valve of the invention in a second rotary position;  
         [0040]      FIG. 19  is a plan view of the alternate embodiment tube valve of  FIG. 18  in a third rotary position;  
         [0041]      FIG. 20  is a plan view of the alternate embodiment tube valve of  FIG. 18  in a fourth rotary position; and  
         [0042]      FIG. 21  is a sectional view taken generally along line  21 - 21  of  FIG. 15 .  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0043]     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.  
         [heading-0044]     General Description of the Apparatus  
         [0045]     The high-speed food patty molding machine  20  illustrated in the figures comprises a preferred embodiment of the invention. The complete machine is describes 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.  
         [0046]     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.  
         [0047]     A control panel  19 , such as a touch screen control panel, is arranged on a forward end of the apparatus  20 .  
         [0048]     As generally illustrated in  FIGS. 1-6 , 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 , 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 .  
         [0049]     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 closed by a conveyor belt  31  of a conveyor  30 . The conveyor belt  31  has a top conveying surface  31   a  that moves the food material longitudinally of the hopper  25  to other components of the food material supply means  24 .  
         [0050]     The food material is moved by supply means  24  into the intake of reciprocating 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 .  
         [0051]     The manifold  27  forms a path 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  and then away from the manifold to a discharge position aligned with a series of knockout cups  33 . When the mold plate  32  is at its discharge position, knockout cups  33  are driven downwardly, discharging hamburgers or other molded patties from machine  20 , as indicated by  33 A in  FIG. 2 . The molded patties are deposited onto a conveyor  29  ( FIG. 1A ), to be transported away from the apparatus  20 .  
         [heading-0052]     Food Supply System  
         [0053]     The food supply means  24  and associated hopper  25  are illustrated in  FIGS. 1-6 . 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 idle roller  37 . A drum motor (not visible) is provided within the drive roller  36  for rotating the drive roller.  
         [0054]     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 hopper outlet  39 . A support plate  43  is affixed to the upper portion of frame  42  extending over the pump opening  39  in hopper  25 . The frame comprises four vertical tie rods  44   a  surrounded by spacers  44   b.    
         [0055]     As shown in  FIG. 4 , two electrical feed screw motors  45 ,  46  are mounted upon the support plate  43  within a motor housing  40 . Motor  45  drives a feed screw  51  that extends partly through opening  39  in alignment with a pump plunger  66  of the pump  61 . Motor  46  drives a 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 .  
         [0056]     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 the controller to interrupt the drive for the roller  36  of conveyor  31 . In this manner the accumulation of food material at the outlet end  39  of hopper  25  is maintained at an advantageous level.  
         [0057]     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 opening  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  of hopper  25  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 end  39  of hopper  25  becomes excessive, conveyor  31  is stopped, as described above, until the supply at the hopper outlet is again depleted.  
         [0058]     The wall of hopper outlet  39  immediately below conveyor drive rollers  36  comprises a belt wiper plate  57  that continuously engages the surface of the conveyor belt  31  to prevent leakage of the food material  38  from the hopper at this point.  
         [heading-0059]     Food Pump System  
         [0060]     The food pump system  26  of molding machine  20  is best illustrated in  FIGS. 2, 4  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 in cylinder  64  (not shown) 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 valve manifold  27  as described more fully hereinafter.  
         [0061]     Preferably, the pump housing  71  and the valve manifold  27  are cast or otherwise formed as a one piece stainless steel part.  
         [0062]     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 .  
         [0063]     Advantageously, the plungers  66 ,  68  and the pump cavities  69 ,  89  have corresponding round cross sections for ease of manufacturing and cleaning.  
         [0064]     As shown in  FIG. 6 , an elongated proximity meter  75  is affixed to the first pump plunger  66  and extends parallel to piston rod  67  into alignment with a pair of proximity sensors  76  and  77 . A similar proximity meter  95  is fixed to and projects from plunger  68 , parallel to piston rod  87 , in alignment with a pair of proximity sensors  96 ,  97 . Proximity sensors  76 ,  77  and  96 ,  97  comprise a part of the control of the two pumps  61 ,  62 .  
         [0065]     The meters  75 ,  95  and sensors  76 ,  77 ,  96 ,  97  monitor the plunger positions in small, precise increments, such as every 0.25 inches.  
         [0066]     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. The pressure applied through pump  61  is sensed by a pressure sensing switch  78  connected to a port of the cylinder  64 .  
         [0067]     As plunger  66  advances, the corresponding movement of proximity meter  75  signals the sensor  76 , indicating that plunger  66  is near the end of its permitted range of travel. When this occurs, 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 from the cavity into manifold  27 . The pressure applied through pump  62  is sensed by a pressure sensing switch  79  connected to one port of cylinder  84 .  
         [0068]     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 .  
         [0069]     Thereafter, when plunger  68  is near the end of its pressure stroke into pump cavity  89 , proximity sensor  96 , signals the need to transfer pumping operations to pump  61 . 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.  
         [0070]     Pump cylinders  64  and  84  can also be actuated to completely retract the two pump plungers  66  and  68  as shown in  FIG. 6  to cleaning positions. When in the cleaning position, the two plungers  66 ,  68  are completely exposed and can be thoroughly cleaned with little difficulty. In addition, retraction of the plungers to cleaning position affords convenient access to the pump cavities  69  and  89  to assure effective cleaning of this part of pump system  26 .  
         [0071]     The valve manifold  27 , shown in  FIGS. 2, 6  and  6 A- 14 , holds a manifold valve cylinder or tube valve  101  fit into an opening  102  in manifold  27  immediately beyond the pump cavity walls  74  and  94 .  
         [0072]     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  27  and both pump cavities  69  and  89 . According to the first embodiment, cylinder  101  also includes an elongated outlet slot  109 . The valve cylinder outlet slot  109  is generally aligned with a slot  111  (see  FIG. 5 ) in housing  71  that constitutes a feed passage for molding mechanism  28 .  
         [0073]     As shown in  FIG. 12-14 , one end wall of valve cylinder  101  includes an externally projecting base end  103  that is connected to a drive linkage  104 , in turn connected to the end of the piston rod  105  of a hydraulic actuator cylinder  106  ( FIG. 2 ).  
         [0074]      FIGS. 2 and 12  illustrate the operating condition maintained for manifold  27  whenever 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  as shown in these Figures. 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 .  
         [0075]     When molding machine  20  changes over from pump  61  to pump  62 , valve cylinder  101  is rotated to its alternate operating condition. This is accomplished by actuator  106 , which advances piston rod  105  to the piston shown dashed as  105   aa  in  FIG. 14  and rotates valve cylinder  101  through a limited angle in a counterclockwise direction until intake slot  107  of cylinder  101  is displaced from the first pump cavity outlet slot  73  so that food material can no longer flow into or out of cylinder  101  from pump cavity  69 . On the other hand, the other intake slot  108  of cylinder  101  is now aligned with the outlet slot  93  from pump cavity  89 , so that food material is forced under pressure through slots  93  and  108  into the interior of cylinder  101  and out of the cylinder through slots  109  and  111  to the molding mechanism of the machine.  
         [0076]     When pumping from cavity  89  of pump  62  is subsequently terminated, and pumping is resumed from cavity  69  of pump  61  as described above, hydraulic actuator  106  again operates to retract piston rod  105 . The movement of rod  105 , through linkage  104 , rotates valve cylinder  101  clockwise back to the position shown in  FIGS. 2, 5 ,  12  and  14 . This restores manifold  27  to the appropriate operating condition for pumping of food material from cavity  69  to the molding mechanism of the machine.  
         [0077]     A pair of proximity sensors  106   a ,  106   b  ( FIG. 2 ) sense the rotational position of the tube valve and communicate with the machine controller.  
         [heading-0078]     Molding Mechanism  
         [0079]     As best illustrated in  FIG. 5 , the upper surface of the housing  71  that encloses the pump cavities  69  and  89  and the manifold  27  comprises a support plate  121  that projects forwardly of the housing, and that affords a flat, smooth mold plate support surface. The mold plate support  121  may be fabricated as a separate plate bolted to, or otherwise fixedly mounted upon, housing  71  and manifold  27 . It includes the upper portion of the manifold outlet passage  111 .  
         [0080]     Mold plate  32  is supported upon plate  121 . 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 . 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  is held in place by six mounting bolts, or nuts tightened on studs,  125 .  
         [0081]     As best illustrated in  FIG. 6 , mold plate  32  is connected to drive rods  128  that extends 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 link  131 . Each drive rod  128  is carried within a guide tube  132  that is fixed between a support plate  134  and the housing  71 . The links  131  are pivotally connected to a crank arm  142 . The crank arms  142  are each driven by a right angle gear box  136  that is driven by a servo motor  138 . The servo motor is preferably a 6-7.5 HP totally enclosed fan cooled motor. The right angle gear box  137  and the right angle gear box  136  are configured such that the crank arms  142  are synchronized to rotate in opposite directions.  
         [0082]     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 mirror image fashion, 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 a tie rod  139 .  
         [0083]     A circular guard plate  135  is fastened on top of each crank arm  142 .  
         [0084]     Molding mechanism  28  further comprises a knockout apparatus  140  shown in  FIGS. 2 and 5 . The knockout apparatus comprises the knockout 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 mold plate  32 ; there is one knockout cup  33  aligned with each mold cavity  126  and the mold cavity size is somewhat greater than the size of an individual knockout cup.  
         [0085]     The knockout apparatus  140  is configured to drive the carrier bar  145  in timed vertical reciprocation.  
         [0086]     During a molding operation, the molding mechanism  28  is assembled as shown in  FIGS. 2 and 5 , with cover plate  122  tightly clamped onto spacers  124 .  
         [0087]     In the apparatus illustrated in  FIG. 5 , a multi fill orifice type fill plate  121   a  is utilized, although a simple slotted fill plate is applicable as well.  
         [0088]     During most of each cycle of operation of mold plate  32 , the knockout mechanism remains in the elevated position, with knockout cups  33  clear of mold plate  32 . When mold plate  32  reaches its extended discharge position, the carrier bar  145  and the knockout cups  33  are driven downward to discharge the patties from the mold cavities. The discharged patties may be picked up by the conveyor  29 .  
         [heading-0089]     Tube Valve System  
         [0090]      FIG. 6A  illustrates the tube valve  101  separate from the apparatus  20 . The tube valve includes the base end  103  and a distal end  404 . The distal end  404  is inserted first into the opening  102  of the housing  71  during installation. The base end  103  includes an end flange  406  having two tapped holes  408  for connection to the drive link  104  by fasteners  409   a  and spacers  409   b  as shown in  FIG. 14 . The base end  103  further includes a groove  410  for a ring seal  411 , such as an O-ring or a D-ring, and a smooth annular surface  412  that is journaled within a base end bearing or bushing  413  shown in  FIGS. 12 and 13 A.  
         [0091]     The distal end  404  includes a reduced diameter guide portion  416  that positions a smooth annular surface  420  into a distal end bearing or bushing  421  as shown in  FIG. 12 . A ring seal  422 , such as an O-ring or D-ring, is positioned within an inside groove  423  of the opening  182 . A smooth annular surface  424  of the distal end  404  engages and seals against the ring seal  422  ( FIG. 12 ).  
         [0092]     As illustrated in  FIG. 13A , both bushings  413 ,  421  include a crown-shaped profile having openings  425  spaced around a circumferential surface that abuts the manifold  27  when installed. Each bushing  413 ,  421  include openings  426  for fasteners to fasten the bushings  413 ,  421  to the manifold  27 , and an inside circumferential grease groove  427  in communication with a grease fitting  428 .  
         [0093]     As illustrated in  FIG. 14 , the linkage  104  includes a lever bar  429  that is fastened to the base end  103  by the fasteners  409   a , and spacers  409   b . The rod  105  includes an extension  105   a  that has a square cross section. The extension has a rectangular notch  105   b  that is open towards a back side of the lever bar  429 .  
         [0094]     A follower block  430  is rotatably connected to the back side of the lever bar  429  by a threaded shank  431  of a knob  432 . In this regard, the follower block  430  includes a block portion  433   a  and a cylinder portion  433   b  having a threaded bore  434  to engage the shank  431 . The lever bar  429  includes a cylindrical bore  436  that receives the cylinder portion  433   b . The cylinder portion  433   b  is free to rotate in the bore  436 .  
         [0095]     The block portion  433   a  is free to vertically slide within the notch  105   b . Three positions of the block portion  433   a  are shown in  FIG. 14 :  433   a ,  433   ab ,  433   aa . Two positions of the lever bar  429  are shown:  429  and  429   aa.    
         [0096]      FIG. 7  illustrates the relative size and orientation of the inlet port  107  with respect to the valve  101 .  
         [0097]      FIG. 8  illustrates the relative size and orientation of the inlet port  108  with respect to the valve  101 .  
         [0098]      FIGS. 9 and 10  illustrate the relative size and orientation of the outlet port  109  with respect to valve  101 .  
         [0099]      FIG. 11  illustrates the respective rotary positions of the inlet ports  107 ,  108  and the outlet port  109  around the circumference of the tube valve  101 . The ports  107 , 108 , 109  have angular expanses of  107 A,  108 A, and  109 A respectively. Preferably, for a 4.4 inch diameter tube valve, given the reference angle 0 degrees shown in  FIG. 11 , the angular position and expanse  107 A is approximately between 205 degrees and 267 degrees, the angular position and expanse  108 A is approximately between 134 degrees and 197 degrees, and the angular position and expanse  109 A is approximately between 0 degrees and 137 degrees. The sidewalls of the ports are not all cut radially, in such cases the angles are taken at the furthest radial point on the sidewall that defines the port.  
         [0100]      FIGS. 15-21  illustrate a second embodiment tube valve  601  and manifold  527 .  FIG. 15  is taken generally along oblique line  15 - 15  of  FIG. 16 .  FIG. 15  illustrates the valve manifold  527  and the pump chambers  69 ,  89  of the pump housing  71  from above, taken from an angle. The mold plate and breather plate are removed in this figure so that the inside cavities of the valve manifold  527  and pump chambers  69 ,  89  are visible. Similar to the previously described embodiment, it is preferred that the pump housing  71  and the manifold  527  are formed as a unitary part.  
         [0101]     The manifold  527  includes three oblong inlet openings  111   a ,  111   b  and  111   c . The openings  111   a ,  111   b  and  111   c  are substantially equal in open area. The openings  111   a ,  111   b ,  111   c  receive food material from the alternate embodiment tube valve  601  shown in  FIGS. 17-20 .  
         [0102]      FIG. 15  illustrates the pump chambers  69 ,  89  empty, i.e., there are no plungers  66 ,  68  shown. On a top surface  650  of the pump housing  71  and/or manifold  527  there are three grooves or indentations  652 ,  654 ,  656  that communicate with bores or holes  652   a ,  654   a ,  656   a , respectively.  
         [0103]     As shown in  FIG. 16 , the first plunger  66  is in a position to begin a filling cycle of food material  660 . A front face  662  of the plunger  66  includes a beveled region  664  around beveled approximately 180°, around a top edge of the plunger  66 , constituting the upper portion of the circumference of the plunger  66 . This bevel is approximately 15° and acts to hold the plunger  66  down given the pressure of the food material within the pump chamber.  
         [0104]     The center groove  654  on the top surface  650  is shown dashed in  FIG. 16 . The center groove  654  extends from the bore  654   a  to an open area  654   b  that is open to the hopper  25 . The other grooves  652 ,  656  and bores  652   a ,  656   a  are similarly configured as that shown in  FIG. 16  for groove  654  and bore  654   a . These grooves  652 ,  656  have open areas  652   b ,  656   b  to the hopper  25 .  
         [0105]      FIG. 17-20  show the alternate tube valve  601  in detail. The alternate tube valve  601  is as described previously as the tube valve  101  except as herein distinguished. When the inlet port  107  is in registry with the pump chamber  69  there are three outlet ports  109   a ,  109   b ,  109   c  that are in registry with the openings  111   a ,  111   b ,  111   c , to pass food material  660  to the molding mechanism  28 .  
         [0106]     As can be seen in  FIG. 17 , the outlet port  109   a  that is closest to the inlet port  107  has a smallest, most restrictive opening, the center outlet port  109   b  has a slightly greater opening, and the far outlet port  109   c  has the greatest opening. This progressive tube valve outlet opening arrangement, with the smallest outlet opening closest to the feeding inlet to the tube valve, assists in equalizing the food product pressure across the width of the manifold  27  and molding mechanism  28 . A more even food product pressure allows for a more consistent density of molded products across a width of the mold plate.  
         [0107]     As seen in  FIG. 18 , the tube valve is rotated so that the second inlet port  108  is in registry with the second pump cavity  89 . The tube valve  601  provides progressive openings  119   a ,  119   b ,  119   c  that are smallest near the inlet port  108  and largest at the opposite end of the tube valve  601 , in mirror image reversal of the openings  109   a ,  109   b ,  109   c  shown in  FIG. 17 . When the inlet port  108  is in registry with the pump chamber  89 , the three outlet ports  119   a ,  119   b ,  119   c  are open to the openings  111   a ,  111   b ,  111   c  to pass food material  660  to the molding mechanism  28 . This progressive tube valve outlet opening arrangement, with the smallest outlet opening closest to the feeding inlet to the tube valve, assists in equalizing the food product pressure across the width of the manifold  27  and molding mechanism  28 . A more even food product pressure allows for a more consistent density of molded products across a width of the mold plate.  
         [0108]     It is also within the scope of the invention that the center ports  109   b ,  119   b  and  111   b  and  119   b  be eliminated and that just two outlet ports  109   a ,  109   c  and  119   a ,  119   c  and corresponding two inlet ports  111   a ,  111   c  be used. As described, the outlet ports  109   c ,  119   c  would be larger than the outlet ports  109   a ,  119   a.    
         [0109]      FIG. 19  illustrates the tube valve rotated so the inlet port  107  and two substantially rectangular surface depressions  710 ,  712  can be seen. The depressions  710 ,  712  have a constant radial depth (preferably about {fraction (3/16)}″ deep) from the cylindrical surface of the tube valve  601 . The center surface depression  710  is slightly longer than the end surface depression  712 . When the first plunger  66  is in operation, pushing food product through the inlet port  107 , the surface depressions  710 ,  712  are in flow communication with the bores  652   a ,  654   a , and the grooves  652 ,  654 .  
         [0110]      FIG. 20  illustrates the tube valve rotated so the inlet port  108  and two substantially rectangular surface depressions  810 ,  812  can be seen. The depressions  810 ,  812  have a constant radial depth (preferably about {fraction (3/16)}″ deep) from the cylindrical surface of the tube valve  601 . The center surface depression  810  is slightly longer than the end surface depression  812 . When the second plunger  68  is operating, pushing food product through the inlet port  108 , the surface depressions  810 ,  812  are in flow communication with the bores  654   a ,  656   a , and the grooves  654 ,  656 .  
         [0111]      FIG. 21  shows the configuration of the tube valve  601  when the inlet port  107  is used. Rectangular recesses  710 ,  712 , communicate with the bores  652   a ,  654   a  and the grooves  652 ,  654  to vent air to the hopper.  
         [0112]     When reloading the pump box with product, the following occurs. For example, when reloading the pump cavity  89  for plunger  68 , the plunger  68  retracts and the feed screws rotate. The combination of the vacuum created by the plunger  68  withdrawing from the pumping chamber, and the turning screws, forces food product in front of the plunger  68 . The plunger is then advanced into the chamber  89  to initially compress the food product before filling begins. As the plunger  68  advances to the pump chamber  89 , there will be air inter-mixed with food product. This air must be removed before the plunger  68  starts its mold plate cavity-filling cycle.  
         [0113]     The plunger  68  advances to compress the reloaded product, while the plunger  66  continues to feed food product through the full open port  107  in the tube valve  601 . The tube valve  601  is blocking the plunger  68  from feeding the food product into the manifold  527 ; however the grooves  710 ,  712  communicate with bores  652   a ,  654   a  in the pump box or manifold  527 . Grooves  652 ,  654  on the manifold and pump housing top surface  650  allow air (but not product) from the pump chamber  89  to escape back to the hopper, during initial compression of the food product within the pump chamber  89  against the tube valve  601 .  
         [0114]     The process alternates with the tube valve rotational shift of about 70 degrees, to change the active plunger  66 ,  68 .  
         [0115]     As a further feature of the invention, a plurality of breather holes  902  are provided at each longitudinal end of the tube valve, through the tube valve wall. The breather holes  902  are in communication with an inside of the tube valve and to an outside circumferential groove  906   a ,  906   b  respectively that is in communication with the depressions  712 ,  812  respectively. Thus, air trapped at either end within the tube valve can be expressed back to the collection area via the breather holes  902 , the grooves  906   a ,  906   b  and the depressions  712 ,  812 .  
         [0116]     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.