Patent Abstract:
A resilient rubber finger and a locking mechanism therefore for use in poultry processing plants for the plucking of feathers off poultry is provided. The rubber-plucking finger is comprised of an oversized base without an annular recess, and a tapered furrowed shank. A plurality of fingers is inserted into a support base through apertures therein. The diameter of the shank proximate the base is substantially equal to the diameter of the support base aperture to ease insertion and removal. A backing plate is provided to abut the rear of the support plate preventing accidental displacement of the rubber finger from the support plate. The support plate is attached to the backing plate using an integrated centrifugal locking mechanism within the backing plate.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   The application is a divisional application of and claims the benefit under 35 U.S.C. 121 of the Nonprovisional patent application Ser. No. 11/098,217 filed Apr. 4, 2005, now U.S. Pat. No. 7,066,805. Nonprovisional patent application Ser. No. 11/098,217 claimed the benefit of the Provisional patent application Ser. No. 60/559,174 filed on Apr. 2, 2004. 

   FIELD OF THE INVENTION 
   This invention relates generally to equipment used in connection with poultry feather picking machines, and particularly to a method of mounting and securing a resilient picking finger in a poultry feather-plucking device. 
   BACKGROUND OF THE INVENTION 
   Machines have been developed for picking or plucking the feathers of poultry for use in poultry processing plants. These picking machines typically have drums and/or discs to which resilient rubber or synthetic picker fingers are mounted. The drums or discs are positioned along each side of a path of travel along which birds are conveyed. The drums or discs are then rotated at speeds as high as 600 to 1250 rpm causing the resilient fingers to be constantly driven into contact with the birds. Frictional forces between the rubber fingers and the feathers remove the feathers from each bird. However, the fingers tend to wear quickly, with an average processing line requiring replacement of from 8,000 to 10,000 fingers per month. With many processing plants running 3 or more processing lines, it is not atypical for a plant to replace one half million fingers per year. 
   The picker fingers typically have an enlarged disc-shaped base formed with an annular recess from which base a tapered, furrowed shank extends. Each finger is installed in a disc with the annular recess of the finger base located within a hole in the support disc or drum (hereinafter referred to as “disc”) with the recess edges abutting and therefore gripping opposite sides of the rim about the hole of the support disc. The finger shank adjacent the annular recess is oversized, i.e., larger than the hole in the support disc, in order to prevent the finger from becoming dislodged when the discs are brought up to operating rotational speeds. However, this oversized arrangement results in substantial difficulty when removing and replacing fingers. Worn fingers are removed from the disc by cutting the finger at its annular recess. The two pieces can then be removed with relatively little effort. A new finger is installed by passing its shank portion from behind the disc through the enlarged hole in the disc until its tapered surface adjacent its enlarged base engages the rim about the hole. The shank is then pulled with a substantial degree of force in order to seat the annular recess about the edge of the hole. 
   It is inherently difficult to seat the picking fingers within the disc holes manually due to the amount of force required in pulling their base portions into the support holes. Because of the orientation of the discs within the processing machinery, it is often difficult to reach the fingers that need to be replaced. Not only is a substantial amount of strength required but also the space available in which to work is usually quite restricted, making it awkward to exert the force needed to properly seat the annular recess within the hole edge. Carpal tunnel syndrome, tendonitis, and other stress related injuries are common among operators who routinely change picking fingers. 
   DESCRIPTION OF THE PRIOR ART 
   U.S. Pat. No. 5,711,703 issued to Peretz discloses an apparatus for removing a rubber finger from a disc or rotational drum. The finger shank is inserted into the apparatus where a blade cuts the finger close to the annular recess. The base of the finger can then be simply pushed through the backside of the disc. This invention does not address the inherent difficulties of inserting new fingers into the disc, but rather is concerned only with the removal of worn fingers. 
   U.S. Pat. No. 5,106,333 issued to Van Dorn et al. discloses a poultry picking apparatus comprising four independently moveable banks of rotating discs. The picker banks can be adjusted to provide a smaller or larger path of travel for processing poultry, in order to optimize feather removal from the carcass. By tilting the banks outward, one can assume that an operator would be granted slightly increased access to the interior of the machine to change the fingers. However, such additional space seems minimal, with the invention being directed to optimization of feather removal, not ease of finger replacement. 
   U.S. Pat. No. 4,514,879 issued to Hazenbroek discloses an apparatus in which the banks of pickers are rotatably mounted around a horizontal axis. The picker banks can be rotated around the axis away from the opposite bank of pickers so that the picking fingers and other elements of the apparatus can be cleaned, repaired, and/or replaced without obstruction from the opposite bank of pickers. While this does alleviate much of the ergonomic difficulty of replacing the fingers, the same amount of pulling force is still required to properly seat the finger&#39;s annular recess about the hole edge. Additionally, this would require the operator to make a large initial capital expenditure to install the rotating banks. 
   U.S. Pat. No. 4,512,072 issued to Graham discloses an apparatus for seating resilient fingers within rotating discs or drums. A housing on the apparatus is situated abutting the support disc so that a finger is inserted into the interior of the apparatus. Upon actuation of a pressurized fluid drive, the apparatus grips the finger and pulls it into the housing interior until the finger is properly seated in the disc hole. While useful in inserting the fingers, this device does nothing to simplify removal. Furthermore, ergonomic and space issues are compounded when an operator is trying to maneuver this apparatus into the confined space allowed by most plucking apparatuses. 
   U.S. Pat. No. 4,329,760 issued to van Mil discloses a plucking machine wherein the circumferential path of travel of the fingers of one disc overlap with the path of travel of adjacent discs. In this manner, fowl limbs are prevented from becoming lodged in the spaces between rotating discs. There is no disclosure relating to the seating or removal of the picking fingers themselves. 
   U.S. Pat. No. 4,292,709 issued to van Mil discloses a picking element wherein the traditional disc or drum has been replaced with a rotating “beaker-shaped” picking element. Problems inherent to the prior art of inserting and removing the rubber fingers are still present. 
   U.S. Pat. No. 3,943,599 issued to Norwood discloses an apparatus for seating rubber plucking fingers, wherein a finger is initially threaded through a hole, and then inserted into the apparatus between a pair of counter-rotating drive rollers. The drive rollers grip the finger, and pull it into the support hole, seating the annular recess within the hole edge. While useful in inserting the fingers, this device does nothing to simplify removal. Furthermore, ergonomic and space issues are compounded when an operator is trying to maneuver this apparatus into the confined space allowed by most plucking apparatuses. 
   SUMMARY OF THE INVENTION 
   Briefly described, the present invention is a novel support disc and rubber finger structure that allows an operator to easily insert and remove plucking fingers from the support disc without the application of excessive force. Furthermore, the operator is not required to contort himself into strange and uncomfortable positions in order to access the picking fingers. Replacement is accomplished easily and comfortably. 
   The novel rubber plucking fingers of the present invention do not have the annular recess and oversized shank that was present in the fingers of the prior art. The fingers can easily be slid through the corresponding holes in the support plate, without the requirement that excess force be used in order to properly seat the annular recess within the hole edge. The rubber finger is therefore only comprised of an oversized base to prevent the finger from being pulled entirely through the support plate hole, and a tapered furrowed shank. The diameter of the shank proximate the base is substantially equal to the diameter of the hole to ease insertion and removal. The diameter of the shank is therefore such that the picking finger can easily rest securely in the support hole, but backward movement of the finger can be easily accomplished with only minimal force being applied. The annular recess should not be confused with the gripping rings or protrusions, which are located remote from the oversized base, as such protrusions are provided to increase frictional forces between the finger and the feathers, and have nothing to do with the retention of the finger within the support base. 
   In order to prevent unwanted movement of the finger within the hole, and possible dislodgement therefrom, a backing plate is provided to abut the rear of the support plate and hold the finger securely. The backing plate is attached to the rotatable shaft so that the backing plate abuts the oversized base of the rubber fingers, preventing accidental displacement of the rubber finger from the support plate. The support plate is attached to the backing plate using an integrated locking mechanism. 
   To ensure that the backing plate and the support plate rotate as a unitary piece, the integral locking mechanism is preferably a centrifugal locking mechanism. When the discs are rotated at full operating speeds, usually between 600 and 1250 rpm, conventional insertion locks such as a clamp-locking device tend to slip, thereby reducing the operating efficiency of the rotating fingers. By employing a centrifugal locking mechanism, the support plate and the backing plate are held together tightly when the disc assembly is rotating at its maximum velocity. 
   OBJECTS OF THE INVENTION 
   It is the principal object of the current invention to provide an improved resilient rubber finger for the plucking of feathers from poultry. 
   It is another object of the current invention to provide an improved resilient rubber finger that can be easily inserted into and removed from apertures in a support disc. 
   It is another object of the current invention to provide an improved resilient rubber finger that can be retained within the support disc without the inclusion of an annular recess in the finger&#39;s shank. 
   It is another object of the current invention to provide a new support disc assembly for use with resilient rubber finger in the plucking of feathers from poultry. 
   It is another object of the current invention to provide a new support disc assembly for use with resilient rubber finger in the plucking of feathers from poultry wherein the new support disc assembly includes a backing plate to prevent the rubber fingers from becoming dislocated through the rear of the support disc. 
   It is another object of the current invention to provide a new support disc assembly for use with resilient rubber finger in the plucking of feathers from poultry wherein the support disc is locked to the backing disc utilizing a centrifugal locking mechanism. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above-mentioned and other features and objects of the invention will become more readily apparent and the invention itself will be better understood by reference to the following detailed description taken in conjunction with the accompanying drawings, wherein: 
       FIG. 1  is a perspective view of the assembled fingers, finger plate, and centrifugal locking mechanism of the current invention. 
       FIG. 2  is an exploded perspective view of the fingers, finger plate, and centrifugal locking mechanism of  FIG. 1 . 
       FIG. 3  is a perspective view of a resilient rubber finger according to the prior art. 
       FIG. 4  is a perspective view of the invented rubber finger. 
       FIG. 5  is a perspective view of the invented base plate. 
       FIG. 6  is a perspective view of the invented top plate. 
       FIG. 7  is a perspective view of the invented slide lock. 
       FIG. 8  is a perspective view of the invented slide clamps. 
       FIG. 9  is a perspective view of the slide lock of  FIG. 7 , shown in conjunction with the slide clamps of  FIG. 8 , in a bolt releasing configuration. 
       FIG. 10  is a perspective view of the slide lock of  FIG. 7 , shown in conjunction with the slide clamps of  FIG. 8 , in a bolt retaining configuration. 
   

   DETAILED DESCRIPTION 
   Referring now to the drawings, and particularly to  FIGS. 1 ,  2 , and  4 , fingers  10  are generally made of a natural rubber, or a synthetic material, that provides adequate surface friction to effectively remove feathers from a poultry carcass, but also are pliable enough so that the carcass is not damaged from repeated impacts by the spinning fingers. Suitable finger materials include, but are not limited to natural rubbers, synthetic rubbers including, but not limited to, styrene-butadiene rubber, isoprene rubber, butadiene rubber, ethylene-propylene rubber, butyl rubber, chloroprene rubber, nitrile rubber, and combinations thereof. It is further contemplated that the natural and synthetic rubber compositions can include various additives, such as tackifiers, pigments, anti-oxidants, anti-UV, etc., and all of such are contemplated, and do not affect the scope of the present invention. 
   The fingers themselves each comprise an enlarged base  12 , and a tapered shank  14 . The base  12  prevents the shank from becoming dislodged from the finger plate  20  at operational speeds. The shank  14  is that operational part of the finger that actually comes into contact with the poultry carcass, and removes the feathers therefrom. Optionally, the fingers can have a grip pattern  16  on their surface, which can be a series of furrows within the shank, or a pattern of extensions from the shank. The grip pattern  16  provides increased friction between the finger and the feathered carcass, which thus improves the removal of feathers when the machinery is in operation. The invented fingers lack the annular grove adjacent the base that is generally present in the fingers of the prior art (See  FIG. 3 ). 
   Finger  10  is threaded through one of a plurality of finger holes  22  on finger plate  20 , so that the base  12  sits snugly adjacent the first side  26  of the finger plate  20 , and the shank extends from the second side  27 . Ideally, the finger  10  has a diameter that is nearly equal to, or slightly larger than diameter of the finger hole  22 . This prevents any excessive rotation of the finger within the finger hole, which would decrease the efficiency of feather removal. 
   Located at the rotational center of the finger plate  20  and extending from the first side  26  is a locking bolt  30  (See  FIG. 2 ). The bolt has a shaft  32 , an annular recess  34 , and a head  36 . The locking bolt is inserted into the centrifugal locking mechanism, as described infra, so that the finger plate is held securely without slippage at operational velocities. 
   The shaft  32  extends though a center aperture  46  on base plate  40 . The base plate  40  has a diameter approximately equal to that of the finger plate  20 . When a plurality of fingers  10  are inserted into the finger plate, the base plate  40  sits snuggly against the fingers&#39; bases  12 , to hold the fingers  10  in place when the assembly is spinning at operational speeds. Intimate contact between the finger bases  12 , and the base plate  40  is necessary to ensure that the fingers do not become dislodged from the finger holes. 
   The base plate  40  has a plurality of screw holes  48  proximate the outer edge of the base plate (See  FIG. 5 ). Preferably, the screw holes  48  are positioned around the base plate  40  so that any torque created by one hole would be cancelled by the other holes. 
   Atop the base plate  40  sits lock plate  50 . The lock plate is also provided with a plurality of screw holes  58  that align with corresponding screw holes  48  on the base plate. 
   A clamp recess  52  is located within and along a diameter of the base plate  50 , so that it overlaps, and sits atop of the base plate center aperture  46 . The clamp recess is an elongated rectangular cutout in the lock plate. A pair of spring indents  56  are located at ends of the clamp recess, proximate to the base plate&#39;s outer edge. 
   A pair of opposing slide clamps  60   a,b  are positioned within the clamp recess. Each slide clamp  60  is provided with a pins  64   a,b . A pair of springs  68   a,b  engage with the spring indents  56   a,b  and also with spring indents  66   a,b  to hold the slide clamps together within the lock plate  50 . Opposed arcuate clamps  62   a,b  form an aperture having about the same diameter as annular recess  34  of the locking bolt  30 . Upon insertion of the locking bolt, the arcuate clamps  62   a,b  engage the locking bolt  30  about the shaft  36  within the annular recess  34 . Springs  68   a,b  ensure that the arcuate clamps maintain intimate contact with the shaft  36  within the annular recess  34 , while the head  32  and shaft  36  prevent unwanted disengagement of the arcuate clamps  62   a,b  from the shaft  36  within the annular recess  34 . 
   Sitting atop the lock plate is the slide lock  70 . A pair of angled pin slides  72   a,b  is provided. The pin slides  72   a,b  mate with the pins  64   a,b . The slide lock is capable of movement normal to that of the slide clamps  60   a,b . Thus, movement of the slide lock in a first direction will produce a tightening effect of the clamps  60   a,b  about the shaft  36  (See  FIG. 10 ), while movement of the slide lock in the opposite direction will cause the clamps  60   a,b  to release from the shaft  36  within the annular recess  34  (See  FIG. 9 ), so that the shaft  36  and the finger plate  20  can be removed from the assembly. The slide lock is provided with a cavity  72 , so that movement of the slide lock will not interfere with operation of the shaft  36  and clamp  60   a,b.    
   Extending from one side of the slide lock is a torque arm  76 . The torque arm  76  extends above the recess  54  of the lock plate  50 . The torque arm  76  acts as a “release button,” in that depression of the torque arm will cause movement of the slide lock effecting a loosening of the arcuate clamps  62   a,b  from the annular recess  34  (See  FIG. 9 ), and providing an easy release of the shaft  36  and the finger plate  20  from the rest of the assembly. 
   The torque arm also is key to proper functioning of the centrifugal lock. The torque arm is purposely out of balance about its central cavity. When the assembly spins about its axis, the torque arm is accelerated away from the axis, creating a force in the A direction. This force causes arcuate clamps  62   a,b  to tighten around the annular recess  34 , whereby slippage of the shaft between the slide locks is minimized. 
   A top plate  80  sits atop the slide lock  70 . The top plate&#39;s underside is hollowed out, so that the slide lock will fit within the hollow, and easily move therein. When properly situated, the top plate&#39;s edges will be in contact with the lock plate, and only the torque arm will be visible as extending out from the top plate. 
   Provided in the top plate is a plurality of screw holes  88  that align with screw holes  48  and  58 . A screw or retaining bolt, not shown, is threaded though each of holes  48 ,  58 , and  88  to hold the entire locking mechanism together. 
   To assemble the device, fingers  10  are inserted into a detached finger plate  20 . The locking bolt  30  of the finger plate  20  is then inserted through the center aperture  46  of the base plate  40 . As the locking bolt  30  presses into the slide clamps  60   a,b , the tapered head  32  causes the slide clamps  60   a,b  to spread slightly, allowing for penetration of the tapered head  32 . Slide clamps  60   a,b  then close around the shaft  36  within the annular recess  34  preventing the inadvertent removal or dislodging of the finger plate  20 . 
   When the assembly begins to rotate, the unbalanced weight of the torque arm  76  provides an outward force normal to the rotational axis of the apparatus. Pins  64   a,b  slide in the pin slides  74   a,b , so that outward forces to the torque arm  76  create a corresponding tightening of the arcuate clamps  62   a,b  about the shaft  36  within the annular recess  34 . This tightening prevents slippage of the shaft  36  within the assembly, which would decrease feather removal efficiency. Slide clamps are shown in the bolt retaining configuration in  FIG. 10 . Furthermore, the tightening prevents the inadvertent disengagement of the locking bolt  30  from the remainder of the device. 
   When fingers  10  need to be replaced, the torque arm  76  is depressed towards the rotational axis (as shown in  FIG. 9 ), which forces the slide clamps  60   a,b  outward from the shaft  36 . The finger plate  20  can then be easily removed from the rest of the assembly. Worn or broken fingers simply slide out of the finger holes  22 , and replaced with new fingers. The finger plate  20  is then replaced into the center aperture  46  as described above, and operation of the assembly can continue. Thus, finger replacement can be accomplished without the awkwardness and difficulty of the prior art devices. 
   SUMMARY OF THE ACHIEVEMENT OF THE OBJECTS OF THE INVENTION 
   From the foregoing, it is readily apparent that I have invented a novel resilient rubber finger and disc assembly for use in connection with poultry feather picking machines, and also to a method of mounting and securing a resilient picking finger in a poultry feather-plucking device. It is further apparent that the resilient rubber finger can be easily inserted into and removed from apertures in a support disc. Furthermore, it is evident that the disc assembly is easily removable, so that an operator undergoes little or no strain in replacing and servicing the fingers. Finally, it is evident that the disc assembly is easily attachable to a rotatable shank utilizing an integrated novel centrifugal locking mechanism. 
   It is to be understood that the foregoing description and specific embodiments are merely illustrative of the best mode of the invention and the principles thereof, and that various modifications and additions may be made to the apparatus by those skilled in the art, without departing from the spirit and scope of this invention.

Technology Classification (CPC): 0