Abstract:
An apparatus for trussing a bird comprising a main body having a platform for supporting the bird, the platform and main body having a bird keel end and a bird wishbone end, clamping means movably mounted on the main body for securing the bird on the platform and releasing the bird from the platform, shackle means mounted on the main body and being disposed above the bird keel end of the platform for receiving and at least temporarily securing the legs of the bird, a leg engaging and supporting means movably mounted on opposite lateral locations of the main body for tightening leg knuckles of a bird into the shackle means before flexing, for preventing twisting of the legs and for bending the legs over the wings, a first drive means operably engagable with the clamping means, the shackle means and the leg engaging and supporting means to sequentially clamp the bird, shackle, stretch and flex the clamped birds legs and to release the clamped bird.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a 35 USC 371 application of PCT/GB 2005/002597 filed on Jul. 4, 2005. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus for trussing a chicken or some similar bird. 
     2. Description of the Prior Art 
     Traditionally, chickens are trussed manually by staff who are generally able to truss two to three chickens a minute. It takes anything from ten to fourteen weeks to train a person up to the level of competence where they can truss two to three chickens a minute. Out of every ten staff who start on this course, only two or three stay any considerable length of time. Additionally, in order to truss the chickens the tendons in the chicken&#39;s legs need to be vigorously flexed to allow the shanks and drumsticks of the chicken to be subsequently folded inside the body cavity of the chicken. The shanks are the end pieces of the chicken&#39;s legs once the feet have been removed and the shanks are connected to the drumsticks which are connected to the thighbones in turn. 
     This vigorous flexing of the chicken&#39;s legs can cause repetitive strain injury in the operative&#39;s joints, which is uncomfortable for the employee and can be costly to the employer. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     It is an object of the present invention to overcome the above outlined problems. 
     Accordingly, the present invention provides an apparatus for trussing a bird comprising a main body having a platform for supporting the bird, the platform and main body having a bird keel end and a bird wishbone end, clamping means movably mounted on the main body for securing the bird on the platform and releasing the bird from the platform, shackle means mounted on the main body and being disposed above the bird ked end of the platform for receiving and at least temporarily securing the legs of the bird, a leg engaging and supporting means movably mounted on opposite lateral locations of the main body for tightening leg knuckles of a bird into the shackle means before flexing, for preventing twisting of the legs and for bending the legs over the wings, first drive means operably engagable with the clamping means, the shackle means and the leg engaging and supporting means to sequentially clamp the bird, shackle, stretch and flex the clamped birds legs and to release the clamped bird. 
     Ideally, a bird leg shank insertion means is movably mounted on the main body to receive and urge a bird&#39;s leg shanks inside the bird&#39;s own body cavity wherein second drive means are operably engagable with the shank insertion means. 
     Preferably, a pressing means is movably mounted on the shackle means and the pressing means is movable relative to the shackle means wherein third drive means are operably engagable with the pressing means. 
     Ideally, compression means are movably mounted on the wishbone end of the main body and the keel end of the main body to engage the wishbone end and the keel end of the bird and to compress these ends together wherein fourth drive means are operably engagable with the compression means. 
     Preferably, the drive means comprises a number of actuators selected from a group consisting of cams, guide rails, pneumatic and electromagnetic actuators. 
     Ideally, the clamping means comprises an elongate clamping bar pivotally mounted on the main body. 
     Preferably, the elongate clamping bar protrudes from the keel end of the main body centrally above the platform. 
     Ideally, the elongate clamping bar has a bird clamping end and a drive means engaging end. 
     Preferably, the shank insertion means comprises a chute movably mounted on a shank insertion bar which is slidably mounted on the main body. 
     Ideally, the chute protrudes from the keel end of the main body and extends into a space above the platform and the clamping means. 
     Preferably, the shank insertion means comprises an associated shank-tucking member slidably movable along the chute. 
     Ideally, the shank-tucking member is normally located at the keel end of the chute and is operable between this normal position and a location along the chute toward the wishbone end of the chute by a shank tucking member drive means. 
     Preferably, the chute is an inverted u-shaped section having mutually opposing cutaway slots on opposite lateral side members of the u-shaped section. 
     Ideally, the chute is pivotally mounted on one end of the shank insertion bar. 
     Preferably, the other end of the shank insertion bar has drive-engaging means. 
     Ideally, the shank insertion bar has a biasing means normally biasing the chute into a retracted position out of the body cavity of the bird. 
     Preferably, the shackle means comprises an elongate bracket extending transverse the main plane of the main body at our about the bird keel end of the main body, the elongate bracket having a u-shaped recess on opposite ends of the elongate bracket for receiving the legs of a bird. 
     Ideally, the pressing means comprises a lever carrying an elongate presser bar having a is rigid roller on opposite ends of the presser bar. 
     Preferably, the leg engaging and supporting means comprises a pair of mirror image rod arrangements each having a substantially horizontal mounting rod pivotally mounted at or about a lateral edge of the bird wishbone end of the main body. 
     Ideally, an elongate member extends from the outer end of the mounting rod and has a plane of rotation substantially parallel to the main plane of the main body, a leg engaging rod being mounted at the end of the elongate member and extending toward the main body. 
     Preferably, a leg supporting rod is mounted on the elongate member adjacent the leg engaging rod and extending in a direction from the bird keel end to the bird wishbone end of the main body. 
     Ideally, the compression means comprises a pusher plate movably mounted on the main body intermediate the chute and the clamping bar and a breast lifting mechanism movably mounted on the bird wishbone end of the main body. 
     Preferably, the pusher plate is mounted on an elongate pusher plate bar which is slidably mounted on the main body. 
     Ideally, the end of the pusher plate bar distal from the pusher plate has means for engaging drive means. 
     Preferably, the pusher plate is inclined at a predetermined angle for optimising shank and leg insertion into the body cavity of the bird. 
     Ideally, the angle of the pusher plate is in the range of 20° to 40°. 
     Preferably, the pusher plate bar has a biasing means normally biasing the pusher plate towards the main body away from the keel of the bird. 
     Ideally, the breast lifting mechanism comprises a breast engaging plate mounted on a lever which is pivotally mounted on the bird wishbone end of the main body, the end of the lever distal from the pivot having means for engaging a drive means. 
     Preferably, the platform is movable relative to the main body. 
     Ideally, the first drive means comprises a clamping guide operably engagable with the clamping means for moving the clamping means between a chicken clamping position and a chicken mounting and releasing position, a leg engaging and supporting means actuator for activating the leg engaging and supporting means between an inoperative position and a leg supporting position and between an inoperative position and a leg stretching position and a means for sealing and releasing the shackle means. 
     Preferably, the third drive means further comprises a pressing guide for operable engagement with the pressing means for moving the pressing means between a normally retracted inoperative mode and an operative fully forward mode for flexing a chickens tendons by bending their shanks forward. Ideally, the fourth drive means, comprises a breast-lifting mechanism guide for operable engagement with the breast-lifting mechanism for moving the mechanism between a normally lowered position into a raised position simultaneously with the action of a second cam surface moving the pusher plate forward to effect compression of the chicken body. Preferably, the second drive means comprises a tucking member actuator for activating the tucking member of the shank insertion means and a first cam surface operably engagable with the shank insertion means to move it between a chicken loading position where the shank insertion means is located over the platform to be inside the body cavity of a chicken and a chicken unloading position, where the shank insertion means is withdrawn out of the body cavity of the chicken. 
     It will also be appreciated that any other suitable type of actuator can also be used if desired and the actuator units described in this specification are only an example of the many actuators freely available to be used to actuate the relevant moving parts of the trussing apparatus and the trussing carousel assembly. 
     Preferably, the elongate clamping bar extends substantially parallel to the longitudinal axis of the platform and main body. 
     Preferably, the drive means engaging end of the elongate clamping bar is a cam-engaging end. 
     Alternatively, the drive means engaging end of the clamping bar is connected to a pneumatic cylinder. The cylinder allows the clamping bar to be adjusted to a range of different clamping positions to compensate for the various positions of the adjustable platform. 
     Ideally, the chicken clamping end and the cam-engaging end of the clamping bar are on opposite sides of the pivot. 
     Ideally, the shank tucking member drive means is electromagnetic, pneumatic or mechanical. 
     Preferably, the shank tucking member drive means is a linear pneumatic cylinder. 
     Preferably, the drive-engaging means of the shank insertion bar is a wheel. 
     Preferably, the pressing means comprises a lever mechanism carrying an elongate pressing bar having a rigid roller on opposite ends of the bar, the bar being spaced apart from the bracket and having a longitudinal axis substantially parallel to the longitudinal axis of the bracket so that movement of the lever causes the rollers to rotate around the u-shaped recesses of the elongate bracket. 
     Ideally, the leg-supporting rod of the leg engaging and supporting means mitigates against rotation of the legs of the chickens during the knuckle-tightening phase and reduces the risk of breakage. 
     Preferably, a wheel is mounted on the pusher plate for engaging the drive means. 
     Ideally, the drive means for engaging the pusher plate wheel is a cam. 
     Preferably, a roller is mounted on the breast lifting mechanism for engaging the drive means. 
     In another aspect of the invention, there is provided a carousel trussing assembly having a rotating table in operable engagement with a carousel trussing assembly drive means for rotating the table and a plurality of bird trussing apparatuses mounted on the rotating table, each of the bird trussing apparatuses comprising a main body having a platform for supporting the bird, the platform and main body having a bird keel end and a bird wishbone end, clamping means movably mounted on the main body for securing the bird on the platform and releasing the bird from the platform, shackle means mounted on the main body and being disposed above the bird keel end of the platform for receiving and at least temporarily securing the legs of the bird, a leg engaging and supporting means movably mounted on opposite lateral locations of the main body for tightening the leg knuckles of a bird into the shackle means before flexing, for preventing twisting of the legs during tightening and for bending the legs over the wings, first drive means operably engagable with the clamping means, the shackle means and the leg engaging and supporting means to sequentially clamp the bird, shackle, stretch and flex the clamped birds legs and to release the clamped bird. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described more fully herein below, with reference to the drawings, in which: 
         FIG. 1  is a perspective view of a trussing apparatus in accordance with the invention; 
         FIG. 2  is a side elevational view of a carousel trussing assembly; and 
         FIG. 3  is a top plan view of the carousel trussing assembly of  FIG. 2 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1  there is shown a trussing apparatus indicated generally by the reference numeral  1 . The trussing apparatus  1  is referred to as a long shank trussing apparatus  1  and is used with birds which have there shanks retained on the ends of their legs. An alternative embodiment of trussing apparatus known as a short shank trussing apparatus is briefly described following the detailed description of the long shank trussing apparatus  1 . The trussing apparatus  1  comprises a main body  2  having a platform  3  for supporting a chicken or other similar bird (not shown) breast bone up. The platform  3  has a chicken keel end  4  and a chicken wishbone end  5 . An elongate clamping bar  7  is pivotally mounted on the main body  2  about pivot  9  and extends from behind the main body  2  therethrough and projects from the keel end of the main body  2  into the space above the platform  3  and into the body cavity of a chicken resting thereon (not shown) in use. The elongate clamping bar  7  has a clamping end  11  and a drive-engaging end  12  carrying a roller  14 . Alternatively, the drive-engaging end  12  may have a mounting bracket for receiving the driving rod of a pneumatic cylinder. 
     A shank insertion arrangement indicated generally by the reference number  15  has a chute  17  pivotally mounted to an elongate shank insertion bar  19  which is slidably mounted in the main body  2 . The longitudinal axis of the shank insertion bar  19  is substantially parallel to the main plane of the main body  2 . 
     The shank insertion bar  19  has a guide bar  20  which carries a biasing device such as a compression spring (not shown) between the rear end wall  22  of the main body  2  and a drive-engaging end  23  of the shank insertion bar  19  distal from the chute  17 . This drive-engaging end  23  also carries a wheel  25 . 
     The chute  17  is an inverted u-shaped section  27  having mutually opposing cutaway slots  28  on opposite lateral side members  29  of the inverted u-shaped section  27 . 
     The chute  17  extends free end  31  first into the body cavity of a chicken through the keel end of the chicken. The chute  17  also has a tucking member (not shown) normally located about the pivotally mounted end  33  of the chute  17  which tucking member is housed within the confines of the u-shaped section  27 . The tucking member is slidably movable from the pivotally mounted end  33  towards the free end  31  of the chute  17  by a pneumatic cylinder  34  having a longitudinal axis parallel to the longitudinal axis of the chute  17 . 
     A pair of shackles  35  is mounted on a mounting block  42  on top of the pivotally mounted end  33  of the chute  17 . The shackles  35  are provided by an elongate bracket  36  extending transverse the longitudinal axis of the chute  17 , the bracket  36  having a u-shaped recess  38  on opposite ends thereof. A lever  41  is pivotally mounted on the mounting block  42 . 
     The lever  41  has an elongate presser bar  45  mounted midway along the length of the lever  41  transverse of and substantially perpendicular to the levers longitudinal axis. The presser bar  45  has a rigid roller  46  on both of its opposite ends. The presser bar  45  is spaced apart from the shackle bracket  36  and the longitudinal axis of the shackle bracket  36  and the longitudinal axis of the presser bar  45  are substantially parallel. A free drive-engaging end  51  of the lever  41  carries a roller  52 . A biasing device (not shown) is mounted intermediate the lever  41  and the mounting block  42  to return the lever  41  to the position shown in the drawing after the lever  41  is pivoted forward by a drive means (not shown) to flex the tendons of the thicken legs held in the shackle bracket  36 . 
     A leg engaging and supporting arrangement indicated generally by the reference numeral  61  comprises a pair of mirror image rod arrangements  62  each having a substantially horizontal mounting rod  63  pivotally mounted transverse the main plane of the main body  2  and extending laterally therefrom at or about the wishbone end of the main body  2 . An elongate bar  65  is mounted on the mounting rod  63  substantially perpendicular to the longitudinal axis of the mounting rod  63  and the elongate bar  65  has a plane of rotation substantially parallel to the main plane of the main body  2 . A leg-engaging rod  66  is mounted on the end of the elongate bar  65 . A leg-supporting rod (not shown) is mounted on the end of the elongate bar  65  with a longitudinal axis substantially parallel to the main plane of the main body  2  and extends in the direction from the keel end to the wishbone end of the main body  2 . Actuation of each rod arrangement  82  is provided by two pneumatic cylinders  71  one of which is mounted between each lateral surface  73  of the main body  2  and both mounting rods  74 , one of which is shown. 
     A bird body compression arrangement indicated generally by the reference numeral  81  has a pusher plate  82  mounted on a pusher plate bar  83  which is slidably mounted in the main body  2  intermediate the shank insertion bar  19  and the clamping bar  7 . The pusher plate bar  83  has a pusher plate guide rod  85  which carries a biasing means such as a compression spring, not shown, intermediate the rear end wall  22  of the main body  2  and the drive engaging end  87  is of the pusher plate bar  83 . The drive engaging end  87  of the pusher plate bar  83  has a wheel  88 . 
     The second component part of the compression arrangement  81  is the breast lifting mechanism  91  comprising a breast-lifting lever  92  pivotally mounted on the wishbone end of the main body  2 . The lever  92  has a breast engaging plate  93  and a free end  94  of the lever  92  has a drive-engaging roller  95 . 
     Referring to the drawings and now to  FIGS. 2 and 3 , there is shown a preferred carousel trussing assembly indicated generally by the reference numeral  101 . In this carousel trussing assembly  101 , a plurality of long shank trussing apparatuses  1  (two of which are shown) are mounted on a rotating table  102 . The table  102  is rotated by a central drive shaft  104  powered by a motor and gearbox  201 . A central cam  105  is fixed and has a first surface for engaging with the wheel  25  of the shank insertion bar  19 . The same cam  105  has a second surface which is operably engagable with the wheel  88  of the pusher plate bar  83 , see  FIG. 1 . A clamping bar circular guide rail is also mounted on a stationary component of the assembly  101  and it has two circumferential portions at different vertical heights for engaging with the roller  14  of the elongate clamping bar  7  to move the clamping bar  7  between a clamping position and a non-clamping position. Additionally, a presser bar circular guide rail and a breast lifting circular guide rail are provided to engage the roller  52  of the presser bar  45  and the roller  94  of the breast lifting mechanism lever  92  respectively at appropriate positions during the rotation of the table  102 . 
     Additionally, a circular shank flexing rail is provided in front of the shackle bracket  36  at the angular positions where the presser bar  45  is urged forward by its associated guide rail and at positions where the cylinders  71  are actuated. The shank-flexing rail is located in front of the shackle bracket  36  at these locations to prevent the shanks from being pressed out of the shackle bracket  36 . A lighting system  202  is also located on the assembly  101  to act as an alarm to indicate to an operator that it is time for a break. 
     In use, the chicken trussing apparatus  1  is mounted on a rotating table  102  or on a linear conveyor system. It will also be appreciated that the chicken trussing apparatus  1  can be operated in a stationary position with suitable electric, pneumatic, mechanical or electromagnetic drive means causing the necessary staged motions of the moving parts of the apparatus  1  under a control means such as a microcontroller avoiding the need for a moving conveyor. 
     The apparatus  1  and assembly  101  is now described in use with a number of apparatuses  1  mounted on the rotating table  102  of  FIG. 2  and  FIG. 3 . Each apparatus  1  passes by an operator who loads a bird onto each apparatus  1  at the desired speed of rotation of the table  102 . The table  102  has variable speeds so that the factory management can adjust the table speed to suit the level of experience of the personnel manning the table  102  at that particular time. The loading operative lifts the chicken by the two legs and positions the bird so as the clamping bar  7  and the chute  17  enters the bird cavity. At this point of rotation of the table  102 , a cam surface of the central cam  105  acts on the cam follow wheel  25  to push the shank insertion bar  19  into a forward bird engaging position. The operative also positions both of the bird&#39;s legs into the corresponding unshaped recess  38  on the shackle bracket  36 . They also push the bird far enough onto the trussing apparatus  1  until the tail of the bird reaches a target spot marked clearly on the clamping bar  7 . 
     When the bird is loaded on the trussing apparatus  1  which is continually rotating at a preset speed, the central cam  105  or a pneumatic cylinder (not shown) forces the drive engaging end  12  of the clamping bar  7  upwards which rotates about pivot  9  thus moving the clamping end  11  downwards which causes the&#39; bird to be clamped between the clamping bar  7  and the platform  3 . The platform  3  is spring mounted therefore it is capable of vertical movement in use compensating for differences in different thickness of back bones of birds. This difference in size is the case in different sizes of birds and also different breeds of chickens. The bird is now securely clamped on the trussing apparatus  1 . 
     The leg engaging and supporting arrangement  61  has two functions. Firstly, it is used to position the chicken&#39;s legs into the shackle bracket  36  correctly and secondly it is used to bend the chicken&#39;s legs forward until they are substantially over the wings. 
     As the bird on the apparatus  1  rotates under a guarded area for operative protection, the legs that are in the shackle bracket  36  pass behind a stationary shackle guide rail. At this stage, a signal actuates the pneumatic cylinders  71  and the leg engaging and supporting mechanism  61  is rotated forward and the leg engaging rod  66  engages the chicken&#39;s legs trying to remove the legs from the shackle bracket  36 . As there is a shackle guide rail in front of the chicken&#39;s legs, they are instead of being removed, pulled down further into the shackle  35  and in turn the hinge point of the shank of the bird is positioned tight down against the shackle  35 . At this time the leg supporting rod support the birds&#39; thighs preventing them from dragging along the shackle guide rail which would cause them to twist and result in leg breakage. 
     When the legs are pulled into the shackle  35 , the presser bar  45  is commenced. The roller  52  is acted on by a circular presser bar guide rail which forces the rigid rollers  46  to move over the shanks forcing the shanks to be bent or stretched over the shackle guide rail which temporarily retains the legs within the shackle  35 . Once the shanks are bent the shackle guide rail which is holding the legs in the shackle  35  no longer needs to be in place in front of the shackle bracket  36 . 
     As the shanks have now been bent, the leg engaging and supporting mechanism  61  is again actuated by the pneumatic cylinders  71  to push the legs out of the shackle  35  and move them fully forward until they are bent right forward until they are almost touching the wings. At this point the leg engaging and supporting mechanism  61  moves backward to its resting position by actuation of the pneumatic cylinders  71 . 
     The bird has now come out of the enclosed protective tunnel area and the two legs are exposed towards an operative who places an elastic band around the two shanks in a figure eight configuration. A loop from the elastic band is pulled forward and positioned over the breast of the bird at the wish bone end. The operative also manually tucks in the wings for visual presentation. 
     At this point the chute  17  is fully extended forward inside the bird and is held forward by use of a circular cam  105 . The operatives, known as the leg operatives, take a leg in each hand and move them back towards the chute  17 . He carefully positions the shanks through the cut away slots  28  in each side of the chute  17  in front of the tucking member. At the same time he carefully positions the elastic band which is in a figure eight around the shanks over the point of the keel bone of the bird. The operatives&#39; role is now finished. 
     As the table  102  continues to rotate the trussing apparatuses  1  enter a second protected tunnel area and a signal actuates the pneumatic cylinder  34  and causes the tucking member to move forward and forces the shanks to bend forward down the inside of the chute  17 . They are now positioned in a shape ready to be directed down the chute  17  into the bird cavity. 
     At this point the pusher plate  82  starts to move forward by actuation of the central cam  105  on wheel  88  and simultaneously the breast support plate  93  starts to move upwards by use of an external guiding cam acting on the roller  95 . 
     The pusher plate  82  continues to move forward and is strategically designed so as it just rides over the top of the shanks which holds the shanks down, but also causes enough aggression so as to push the shanks and legs forward towards the cavity of the bird. 
     As this pusher plate  82  is moving forward so also is the breast engaging plate  93  moving to push the breast high up over the legs. When both have finished their movement, the keel of the bird is on a vertical plane and behind the shanks of the bird. 
     Both the pusher plate  82  and the breast engaging plate  93  remain in this position and hold the bird effectively exerting pressure towards each other with the bird held in the middle. At this stage the surface of cam  105  acting on wheel  25  allows the chute  17  to move backwards out of the bird. 
     As the chute  17  moves out of the bird, the keel of the bird and the shanks remain in their held position and the keel that has the elastic over it is pulled down tightly over the shanks. 
     The pusher plate  82  and the breast engaging plate  93  both move back to their resting positions as a result of disengagement with their respective cam surfaces and the bird is held together by the tension of the elastic band. The trussing apparatuses now move out of the second protected tunnel. At this stage the pressure exerted on the clamping bar  7  is relaxed as a result of disengagement of the wheel  14  from the its associated cam surface allowing the bird to be manually or automatically removed leaving the trussing apparatus  1  empty and available for reloading as it passes in front of the loading operative and ready to commence another cycle. 
     In the manual tying of chickens each operative is exposed to strenuous repetitive strain injury, RSL. In this invention, the strenuous jobs which are the bending of shanks and bending of legs and the insertion of shanks into the body cavity are removed from the operator immediately reducing the effects of RSI. With a view to reducing the harmful effects of RSI even further, the assembly has a three coloured stacked light system, which changes colour at an interval, deemed suitable by the health and safety team of the factory going to use the machine. This is fully adjustable from 1 min to 24 hours, although 30 mins appears an acceptable time frame. This if properly managed should create a management tool to minimise RSI. 
     In a second embodiment of trussing apparatus, referred to as a short shank trussing apparatus, the identical components as used and described above in relation to the long shank trussing apparatus  1  are used apart form the components required to flex the shanks and insert them into the body cavity of the bird. The components which are omitted from the short shank trussing apparatus are the chute  17 , the lever  41 , the presser bar  45 , the rollers  46 , the shank tucking member and the pneumatic cylinder  34 . Additionally, there is no requirement for the components forming part of the compression arrangement  81 . The second embodiment is referred to as the short shank trussing apparatus because the birds&#39; shanks are removed from their legs before trussing begins. In one particularly preferred embodiment of short shank trussing assembly a saw is mounted on the assembly and cuts the birds&#39; shanks off their legs as a first stage of the trussing operation. The saw may be mounted on the assembly at or about the location where the shackle guard rail first passes in front of the shackle to clamp the birds&#39; legs therein. The saw may be mounted on an internal portion of a guard and is optionally an electrically powered saw. 
     In use of the second embodiment of short shank trussing assembly, all of the steps other than the shank insertion steps, the pressing steps and the compressing steps are carried out. 
     Variations and modifications can be made without departing from the scope of the invention as defined in the appended claims.