Abstract:
A lift assist assembly ( 20, 20   a ) is provided to facilitate transfer of individual segments ( 24 ) of linked food products (e.g., hot dogs) between a first location such as a linker output ( 40 ) to a second, spaced location such as a smokehouse delivery rail assembly ( 30 ). The assembly ( 20 ) includes an elongated rail ( 52, 228 ) supporting a depending lift unit ( 34 ) and a lower, transverse transfer arm assembly ( 36 ). The transfer arm ( 36 ) is equipped with selectively extensible and retractable hooks ( 200 ) designed to engage and support the segments ( 24 ) during transfer thereof; preferably, the hooks ( 200 ) are controlled by a pneumatic control circuit ( 92 ) so as to automatically retract upon transfer of a food segment at the second, delivery location. The assembly ( 20 ) allows the operator to transfer multiple segments ( 24 ) without the physical strain associated with manual transfer thereof.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is broadly concerned with operator-controlled lift assist assemblies specifically designed to transfer segments of linked food products such as hot dogs from a conventional linker output device to the input rail assembly of a smokehouse. More particularly, the invention is concerned with such assemblies and methods which include a generally horizontally extending arm supported by a lift unit for selective raising and lowering of the arm, and wherein the arm has selectively extensible load-bearing elements for supporting food segments. The arm and lift unit are preferably mounted on an overhead rail allowing translatory shifting movement of the lift unit and arm between the linker and smokehouse input rail assembly. The invention eliminates arduous manual lifting and carrying of food segments. 
         [0003]    2. Description of the Prior Art 
         [0004]    In the production of linked food products such as hot dogs, conventional linker units receive an incoming meat emulsion, stuff the emulsion into elongated casings, and twist the filled casings at spaced locations in order to created an elongated string of the linked products. The linked product output is continuously draped onto a linker output device such as an endless, moving, vertical or horizontal track. In order to complete production of the linked products, they are generally passed through a smokehouse for cooking. Typical smokehouses have transfer rail systems leading from an input point and through the smokehouse for final cooking of the products. 
         [0005]    Normally, the output from the linker cannot be directly placed on the smokehouse rail system. Accordingly, individual segments of the linked product (which may weigh 30 lbs. or more) must be transferred from the linker output to racks mounted on the smokehouse input rail. Heretofore, this transfer of linked food product segments has been a manual labor operation. Such transfers involve passing a hooked rod beneath a segment of the linked product draped over the linker output device, followed by lifting the entire segment by the rod ends. The entire rod/food segment assembly must then be carried to the smokehouse input rail and manually mounted on an empty rail hanger. 
         [0006]    When it is considered that such transfers may be made two or three times per minute, it will be appreciated that the labor involved in transferring the product segments is considerable. Indeed, manufacturers have been obliged to hire individuals of large stature and considerable upper body strength in order to perform the transfer operation over an eight hour shift. This practical necessity eliminates most women and many smaller men from this work category. 
         [0007]    While various lift assist devices mounted on overhead rails have been proposed in the past and commonly used in many industries, heretofore no specifically designed lift assist assembly has been provided for the transfer of linked food product segments between a linker output device and a smokehouse rail assembly. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention overcomes the problems outlined above and provides apparatus for transferring individual segments of linked food product from a first location such as a linker output device to a spaced second location such as a smokehouse input rail assembly. The apparatus preferably comprises an elongated, generally horizontally extending arm assembly having a plurality of load-bearing elements projecting therefrom and operable to support a food product segment. The assembly also has a lift unit operably coupled with the arm assembly for selective raising and lowering thereof, and an elongated rail operably supporting the lift unit and arm assembly and permitting translatory movement of the lift unit and the food segment-loaded arm assembly along a selected path of travel generally between the first and second locations. The load-bearing elements of the arm assembly are operable to engage and support a food segment at the first location. The food segment-loaded arm assembly and lift unit are shiftable along the length of the rail towards the second location in order to permit delivery of the supported food segment to a support component at the second location, and to disengage the elements from the food segment. 
         [0009]    In preferred forms, the support rail is pivotal about a first upright axis while the arm assembly is pivotal about a second upright axis separate from the first axis. This allows accurate movement and positioning of the arm assembly for pickup and delivery of the food segments. Also, the arm assembly preferably has a plurality of hooks for engaging and supporting the food segments, with the hooks being selectively extensible and retractable. Control apparatus is provided to extend the hooks and permit loading thereof with a food segment at the first location, and to retract the hooks after delivery of the food segment at the second location. This control apparatus is operable to exert a retraction force upon the hooks while the hooks are under a load supporting the food segment, and to thereby automatically retract the hooks after delivery of the food segment at the second location. Operating buttons for control of the entire transfer apparatus are preferably provided on the arm assembly. 
         [0010]    A corresponding method of transferring individual segments of linked food product from a first to a second location also forms an aspect of the invention. The method comprises the steps of providing an elongated, generally horizontally extending arm assembly having a plurality of load-bearing elements projecting therefrom, and moving the arm assembly to a position adjacent the segment, and causing the elements to engage and support the load of the food segment. In the next step, the loaded segment is moved by translation of the arm assembly to a position adjacent the second location, followed by delivery of the food segment at the second location by transferring the food segment to a support component at the second location, and disengaging the elements from the food segment. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective view of a pair of lift assist systems in accordance with the invention, illustrated adjacent a pair of linker devices and operable to transfer individual segments of linked food products from the linkers to a smokehouse delivery rail apparatus; 
           [0012]      FIG. 2  is a fragmentary perspective view illustrating the first step in the use of a lift assist system for transfer of an individual linked food product segment; 
           [0013]      FIG. 3  is a perspective view illustrating the operator side of a transverse arm assembly forming a part of a lift assist assembly; 
           [0014]      FIG. 3   a  is a fragmentary perspective view illustrating the operator handle end of the assembly depicted in  FIG. 3 ; 
           [0015]      FIG. 4  is a perspective view illustrating the work side of a transverse arm assembly forming a party of a lift assist assembly; 
           [0016]      FIG. 4   a  is a perspective view depicting one of the rod-engaging hook devices of the transverse arm assembly, and illustrating the operation thereof in phantom and full lines, respectively; 
           [0017]      FIG. 4   b  is a vertical sectional view of the hook device illustrated in  FIG. 4   a;    
           [0018]      FIG. 5  is a fragmentary plan view illustrating initial placement of a lift assist assembly of the invention, prior to engaging a segment of linked food products; 
           [0019]      FIG. 6  is a side elevational view of a lift assist assembly in the  FIG. 5  position thereof; 
           [0020]      FIG. 7  is a fragmentary plan view illustrating initial engagement of a lift assist assembly with a segment of linked food product, prior to lifting and removal thereof from the linker output track; 
           [0021]      FIG. 8  is a side elevational view of a lift assist assembly in the  FIG. 7  position thereof; 
           [0022]      FIG. 8   a  is a side elevational view of a lift assist assembly during engagement of during use of the assembly to remove a segment of linked food product from the linker output track; 
           [0023]      FIG. 8   b  is a side elevational view similar to that of  FIG. 8   a , but illustrating the lift assist assembly upon full removal of a segment of linked food product from the linker output track; 
           [0024]      FIG. 9  is a fragmentary plan view illustrating a lift assist assembly during transfer of a segment of linked food product from the linker output track to the smokehouse delivery rail assembly; 
           [0025]      FIG. 10  is a side elevational view of a lift assist assembly in the  FIG. 9  position thereof; 
           [0026]      FIG. 11  is a fragmentary plan view illustrating a lift assist assembly during the next step of transfer of a segment of linked food product from the linker output track to the smokehouse delivery rail assembly; 
           [0027]      FIG. 12  is a side elevational view of a lift assist assembly during initial placement of the supported segment of linked food product onto a hangar forming a part of the smokehouse delivery rail assembly; 
           [0028]      FIG. 13  is a fragmentary view illustrating the operation of a lift assist assembly after transfer of a segment of linked food product onto a hangar forming a part of the smokehouse delivery rail assembly, with the operation being illustrated in phantom and full lines respectively; 
           [0029]      FIG. 14  is a fragmentary perspective view with parts broken away, illustrating the internal construction of a vertical lift unit forming a part of a lift assist assembly of the invention, and wherein the vertical lift unit is in its fully extended position; 
           [0030]      FIG. 15  is a fragmentary vertical sectional view of the primary lift cylinder and related components forming a part of the vertical lift unit as depicted in  FIG. 14 ; 
           [0031]      FIG. 15   a  is a fragmentary view in partial vertical section illustrating the configuration of a vertical lift unit in the fully retracted position thereof; 
           [0032]      FIG. 16  is a fragmentary vertical sectional view of the primary lift cylinder and related components forming a part of the vertical lift unit as depicted in  FIG. 15   a;    
           [0033]      FIG. 17  is a perspective view of a pair of lift assist assemblies of the invention, shown supported on floor mounts; and 
           [0034]      FIG. 18  is a schematic block diagram depicting the preferred components and connections of the pneumatic control circuit for a lift assist assembly in accordance with the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1-16 and  18   
       [0035]    Turning now to the drawings,  FIG. 1  illustrates a pair of identical lift assist assemblies  20  and  22  shown in side-by-side relationship and operable for transferring individual segments  24  of linked food product from linkers  26  and  28  to a smokehouse delivery rail assembly  30 . Inasmuch as the assemblies  20 ,  22  and linkers  26 ,  28  are identical, only assembly  20  and linker  26  will be described in detail. 
         [0036]    In more detail, the assembly  20  broadly includes a ceiling mounting assembly  32 , a vertical lift unit  34  supported by and depending from the rail  52 , and a transverse arm assembly  36  supported by vertical lift unit  34 . The linker  26  is entirely conventional and includes a linking device  38  operable to create interconnected, linked food products such as hot dogs and to place individual segments  24  thereof onto an endless, oval-shaped track  40  having a series of outwardly extending hooks or tines  41  ( FIG. 5 ). As best seen in  FIG. 6 , each segment  24  has an apex  24   a  supported by tines  41 , a pair of diverging, downwardly extending sections  24   b  and  24   c , and a bottom section  24   d  The smokehouse delivery rail assembly  30  broadly has a stationary rail  42  leading to a smokehouse (not shown), together with series of ganged hangars  44  supported and moveable along the length of the rail  42 . Each hangar  44  has somewhat S-shaped upper and lower sections  44   a  and  44   b , as well as upper and lower support clips  45  adjacent the front ends thereof ( FIGS. 9 and 10 ). 
         [0037]    The ceiling mounting assembly  32  is best illustrated in  FIG. 2  and includes a fixed bracket  46  designed to be directly secured to an overhead ceiling, with a depending, gusseted mounting tube  48  secured to the underside of the bracket  46 . A pivot tube  50  is secured within tube  48  and is directly connected to all elongated rail  52 , in order to allow the rail to pivot about an upright axis. A pair of reinforcing struts  54  are secured to the exterior of pivot tube  50  and rail  52  as shown. Coiled compressed air line  58  and exhaust line  56  are also supported on bracket  46 , with line  58  connected to a compressed air source P ( FIG. 18 ). The rail  52  includes an upright main body  60  as well as laterally extending roller tubes  62  and  63 . 
         [0038]    The vertical lift unit  34  includes an upper carriage  64  moveable along the length of the roller tubes  62  and  63 , a housing  66  depending from carriage  64 , and an internal operating assembly  68  ( FIGS. 14-16 ). Carriage  64  ( FIG. 14 ) presents a generally U-shaped channel  70  defined by upright, spaced apart, L-shaped walls  72  located on opposite sides of rail  52  and supporting two mated pairs of rollers  74 , each pair made up of an upper roller  74   a  and a lower roller  74   b . As illustrated, the rollers  74   a  and  74   b  are located on opposite sides of main body  60  and move along the lengths of the roller tubes  62  and  63 . The housing  66  includes an upper plate  76  secured to the carriage walls  72  as well as interconnected depending front and rear walls  78 ,  80 , and sidewalls  82 ,  84 , and an apertured bottom wall  86 . The walls  78 - 86  cooperatively form a generally trapezoidal housing structure. 
         [0039]    Internal operating assembly  68  ( FIGS. 14-16 ) has a primary, double-acting pneumatic lift cylinder  88  with a depending extendable cylinder rod  90 , with the cylinder  88  being controlled via a pneumatic control circuit  92  described in detail below. An elongated pipe  94  is secured to the lower end of rod  90  by means of a connection cage  96  and extends through bottom wall  86  of housing  66 . The cage  96  has an apertured top wall  98  receiving the lowermost end of rod  90 , a pair of upright side walls  100  and a bottom disc  102  secured to the upper end of pipe  94 . The up and down reciprocal motion of pipe  94  is guided by a tubular bushing housing  104  secured to the underside of housing wall  86  and having internal bushings (not shown) engaging the outer surface of pipe  94 . The lowermost end of pipe  94  is equipped with an internally threaded segment  106  which receives the upper threaded end of a rod  108 . A tubular thread cover  110  having an uppermost nut  112  is also threaded onto rod  108 , with the nut  112  abutting the underside of segment  106 . 
         [0040]    The operating assembly  68  further includes a stationary control assembly  114  which is operably coupled with pneumatic control circuit  92  in order to control the operation of primary lift cylinder  88  and transverse arm assembly  36 . The assembly  114  ( FIGS. 14-16 ) has an apertured horizontal plate  116  supporting an upright, apertured synthetic resin bushing block  118  and mounted upon a pair of upright, diagonally opposite, all-thread frame rods  120 ,  122  having the lower ends thereof secured to bottom wall  86  by means of nuts  124 . As illustrated, cylinder rod  90  extends through bushing  118  and plate  116 . A stop block  126  is also supported on the rods  120 ,  122  below plate  116  and is adjustably located thereon by means nuts  128 ,  130 . The stop block  126  has a large central through-opening  132  allowing passage of pipe  94  there through. Additionally, it carries a pair of opposite, double-acting pneumatic pancake cylinders  134 ,  136  each having a rod  134   a ,  136   a  which may be selectively extended inwardly into opening  132  adjacent pipe  94 . 
         [0041]    The pneumatic control circuit  92  is made up of a series of wholly conventional components coupled in a conventional way to achieve the desired and novel control sequences for the operating assembly  68  and transverse arm assembly  36 . Accordingly, those skilled in the art will understand that a variety of different hardware components and hookups could be employed, given the desired control sequences. In preferred forms however, the circuit  92  includes upper and lower speed control fittings  138 ,  140  coupled with cylinder  88 . A pair of pneumatic supply and exhaust fittings  141  and  142  are also provided; the supply fitting  141  is operatively coupled with compressed airline  58 , and exhaust fitting  142  is coupled with exhaust line  56 . The circuit  92  additionally has a pair of air-piloted, four-way, two-position valves  144 ,  146 , logic component  148 , and directional control valve  150 . The valve  150  is equipped with a pair of timers  152 ,  154 . The bushing block  118  also carries a pair of plunger-operated valves  156  and pneumatic fittings  158 . 
         [0042]    The transverse arm assembly  36  is best depicted in  FIGS. 3-4   b  and broadly includes a generally L-shaped wall  160  secured in a cantilever fashion to the lower end of rod  108  by means of gusset  162  and presenting the operator side of the arm assembly. The wall  160  includes a pair of upper and lower horizontal gripping slots  164 ,  166 , with a pair of operator buttons  168 ,  170  on each side of the slots  164 ,  166  for raising and lowering the arm assembly  36  respectively. Additionally, the wall is equipped with an outwardly projecting, end-mounted operating handle  172  also having arm-raising and -lowering operator buttons  174 ,  176 . 
         [0043]    The opposite or work side of arm assembly  36  includes three synthetic blocks  178 ,  180 , and  182  secured to wall  160  via threaded fasteners  184  and cooperatively presenting a pair of upright lift hook assembly slots  183 . As shown, intermediate block  180  has an elongated slot  181  with a solid horizontal handle piece  181   a  located between the wall slots  164 ,  166 . A pair of double-acting, pneumatic pancake cylinders  186 ,  188  are located at the juncture between blocks  178  and  180 , and blocks  180  and  182 . The cylinders  186  and  188  are coupled with and control a pair of identical lift hook assemblies  190 ,  192 ; because these assemblies are identical, only assembly  192  will be described in detail. 
         [0044]    Specifically, the air cylinder  188  includes an upwardly extending plunger  194  which is slidable within a vertical bore  196  formed in block  180 . A transverse threaded bore  198  extends through the plunger  194  as best seen in  FIG. 4   b . A lift hook  200  having a motion slot  202  therein is secured to block  180  by means of pivot screw  204 . An operating arm  206  is likewise pivotly coupled to block  180  via pivot  208  and has a bushing screw  210  slidable within slot  202 . A threaded coupling screw  212  extends through arm  206  and is received within transverse bore  198  of plunger  194 . The preferred geometry of the hook  200  and operating arm  206  assure that when the hook  200  is fully extended as illustrated in  FIGS. 4   a  and  4   b , the hook is in an over-center position relative to arm  206 . Also, when the plunger  194  is retracted the hook  200  and arm  206  are essentially completely contained within the confines of slot  183 . The significance of these features will be explained below. Compressed operating air is delivered to arm assembly  36  via coiled air line  214  extending to unit  34  and connected to valve  150 . 
         [0045]      FIG. 18  illustrates in schematic block form the preferred interconnection of the components of control circuit  92 . The connection lines shown in full line operate at positive pressure delivered via fitting  141 , whereas the dotted lines represent exhaust lines leading to fitting  142 . The logic and control application of circuit  92  will be explained below in the context of operation of lift assembly  20 . 
       Operation 
       [0046]    Returning to  FIG. 2 , the use of lift assembly  20  for transferring individual segments  24  of linked food products will be described. Initially, the hooks  200  are fully extended, and the vertical lift unit  34  is in its lowermost position illustrated in  FIGS. 6 ,  8  and  15 . In the first step, the operator grasps arm assembly  36  using handles  181  and  172 , with the hooks  200  in their fully extended position illustrated in  FIGS. 4   a  and  4   b.  The operator then inserts the hooks through section  24   b  between the vertical strings of linked food products. This is accomplished simply by moving arm assembly forward so that the hooks  200  extend through section  24   b  and into the confines of the segment  24 . This movement is permitted by virtue of the fact that rail  52  is pivotal about the upright axis defined by tube  50 . The operator next grasps a conventional hooked hanger rod  216  ( FIG. 6 ) and inserts the rod along the length of the segment  24  beneath apex  24   a , between the sections  24   b  and  24   c , and rests the rod on the hooks  200 . 
         [0047]    The operator next depresses one of the lift buttons  174  while withdrawing the arm assembly  36 . Depression of the button  174  shifts control valve  146 , which pressurizes cylinder  88 , causing rod  90  to retract. The combined upward and outward motion of the assembly  36  causes the rod  216  to engage the section  24  at the interconnection between highest and next links in the section  24   b  of segment  24 . This is illustrated in  FIG. 8   a.  Such engagement and continued upward movement of the lift unit  34  causes the entire segment  24  to be lifted off of the tines  41  and assume the position illustrated in  FIG. 8   b,  where the apex  24   a  has been shifted by one link. 
         [0048]    Further upward movement of the unit  34  continues until top wall  98  of cage  96  engages the underside of plate  116 . This in turn actuates the valves  156 , shifting valve  144  and valve  146  (the latter through logic element  148 ). This has the effect of extending the stop rods  134   a  and  136   a,  and also causing the rod  90  to begin to shift downwardly. The rod  90  descends until the plate  102  encounters the extended stop rods  134   a,    136   a.  This positions the rod  216  supporting the segment  24  at the proper height for transfer to one of the hangers  44 . The operator then manipulates arm assembly  36  to move the lift unit and arm  36 , the latter carrying the rod  216  and segment  24 , towards rail assembly  30 . Generally, the operator moves these components along an exemplary path of travel  218  illustrated in  FIG. 5 . 
         [0049]    As the operator moves assembly  20  along path  218  an empty rack  44  is approached; this typically involves both pivoting the assembly about the axis of tube  50  and also by translatory movement of the unit  34  and assembly  36 . This travel is illustrated in  FIGS. 9 and 11 . 
         [0050]    Once the travel along path  218  is completed, the assembly  36  and supported segment  24  are adjacent the opposite end of rail  52  as shown in  FIG. 11 , close to an empty hanger  44 . The operator then pivots the assembly  36  as necessary to align and position the rod  216  with the empty hanger  44 . This can occur owing to the pivotal connection between rod  90  and cage  96 . Once aligned, the operator moves the arm  36  along the length of the empty hanger  44 , sliding hook  216  and the supported segment  24  along the length of the S-shaped section  44   a  of hanger  44  until the end of the rod  216  engages the far end of the hanger; at this point the near end of the rod  216  is positioned directly above the upper support clip  45 . The operator then depresses the button  176  on handle  172 , which shifts valve  144 , in turn retracting stop rods  134   a,    136   a,  and allowing further descent of rod  90 . In addition, this initiates operation of timer  152  which, when timed out, shifts valve  150 . Shifting of valve  150  actuates the cylinders  186  and  188  which in turn exerts a retractive force on the hooks  200 ; this also initiates operation of timer  154 . Initially, however, the hooks  200  do not retract owing to the fact that they still retain the load of the hook  216  and supported food segment  24 . 
         [0051]    Further downward movement of the assembly  36  causes the near end of the rod  216  to engage clip  45  so that the hanger  44  takes all of the load of the hook  216  and segment  24 . At this point the retractive force previously exerted on the hooks  200  comes into play, causing them to fully retract within the slots  183 . This permits the operator to easily withdraw the assembly  36  fully through section  24   b  and from the racks  44  without disturbing or damaging the food segments  24 . The operator can then traverse path  218  back to the linker track  40  to reload the assembly  20 . During the course of this return travel, the timer  154  times out, operating the cylinder  186 ,  188  so that the hooks  200  are again extended. This takes the operator back to the starting position to allow a repeat of the forgoing method steps. 
         [0052]    In the embodiment of  FIGS. 1-16  and  18 , the bottoms of the hangers  44  are designed with S-shaped portions  44   b  and clips  45  to accept a second rod  216  and segment  24 . This is best seen in  FIGS. 1 and 2 , where it will be observed that the rail  42  has an elevated section so that the initially loaded hangers  44  present lower ends at an appropriate height for secondary loading using assembly  20 . Of course, single-use racks can also be employed. 
       FIG. 17 
       [0053]      FIG. 17  illustrates floor-mounted lift assist assemblies  20   a  and  22   a  which are identical to the above-described assemblies  20  and  22  except that, in lieu of the ceiling mounting assemblies  32 , floor-mounting assemblies  220  are employed. The assemblies  20   a  and  22   a  are identical, and thus only assembly  20   a  will be described. Furthermore, the assembly  20   a  has a lift unit  34  and arm assembly  36  which are identical with that of the first embodiment. 
         [0054]    The support assembly  220  includes a floor-mounted, gusseted base  222  which supports an upwardly extending, essentially vertical standard  224 . A pivot arm  226  is secured to standard  224  adjacent the upper end thereof, with the arm  226  supporting a cantilever rail  228 . A strut  230  extends between arm  226  and rail  228  to provide further support. The rail  228  has an elongated main body  232 , as well as side flanges  234  and  236 . The carriage  64  forming a part of lift unit  34  travels along the length of rail  228  in the manner previously described. 
         [0055]    Use of the assembly  20   a  is essentially identical with that of the corresponding assembly  20 , except that pivoting of the rail  228  occurs about the axis of side-mounted pivot arm  226 , rather than the axis of tube  50 . Moreover, the path of travel traversed by the unit  20  between the loading track  40  and the rail assembly  30  would have a configuration different than that of the exemplary path  218  of the first embodiment.