NZ201831A - Removing gambrels from carcasses - Google Patents

Description

(831 C% 'HI N.Z. No. 201831 7 September 1982 NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION METHOD AND APPARATUS FOR REMOVAL OF GAMBRELS FROM CARCASSES We, THE MEAT INDUSTRY RESEARCH INSTITUTE OF NEW ZEALAND INCORPORATED, a body incorporated and existing under the laws of New Zealand of East Street, Hamilton, New Zealand, do hereby declare the invention for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- 201 S31 This invention relates to a method of and apparatus for removal of gambrels from carcasses.

Conventionally, in abattoirs and other meat processing plants, operations such as preparing, dressing and freezing carcasses take place with the carcasses suspended from gambrels, the gambrels being hooked into the hind legs of the carcass and generally retained in place even when the carcasses are frozen. The aforesaid processing operations can also include the wrapping of the carcass such that wrapping takes place whilst the carcass is either suspended by the gambrel, or as disclosed in our New Zealand Patent Specifications 195874 and 196035 whilst the lower end of the carcass is supported by a support means.

At some stage in the processing of the carcasses therefore the gambrels must be removed, and this removal is usually carried out manually. In a plant with a large daily output, manual removal of gambrels constitutes a labour intensive operation. In addition the gambrels can be difficult to extract from frozen meat due to the fact that the weight of a carcass depends from the gambrel during the freezing stage. As a result the gambrel becomes locked in place and considerable force is required to enable it to be freed.

Methods of and apparatus for the removal of gambrels from carcasses have been previously proposed and these usually incorporate orientation means so that the carcasses are placed in a uniform orientation prior to the gambrels being 201831 mechanically removed. For example in New Zealand Patent Specification 194364 of W. & R. Fletcher (N.Z.) Limited there is disclosed a method and means of the removal of bachelor type gambrels from carcasses. These gambrels are of a type which are held captive on a conveyor skid. Such gambrels do not present the same problems associated with the removal of standard (i.e. conventional) gambrels primarily because of the firm attachment between the swivelling hook portion of the skid and the central ring section of a bachelor gambrel. In addition the two points of a bachelor gambrel face in the same direction so that only a single sideways movement is required to clear both legs of the carcass. With standard gambrels on standard skids there is not the same fixation between the skid hook and the gambrel and the points of the gambrel face outwardly in opposite directions. Accordingly two movements in opposite directions are required to effect separation and removal of the gambrel from the carcass.

The principle object of the present invention is therefore to provide a method for enabling mechanical removal of standard gambrels from carcasses and also apparatus for carrying out such method of removal.

In accordance with a first broad aspect of the invention there is provided a method of mechanically removing gambrels from carcasses, the method comprising the steps of conveying carcasses in succession to a gambrel removal station, each carcass being suspended from an overhead skid of a conveyor by 3 1o\tr3l T n -r ^ ^ i b u i Lrcr an individual gambrel remoying said gambrel from engagement with said skidf moving said gambrel such that a portion thereof is moved into a predetermined position, clamping a portion of said gambrel in clamping means and moving said clamping means relative to the carcass such that the two opposite extremities of the gambrel are removed in turn from said carcass.

According to a second broad aspect of the invention there is provided apparatus for removing gambrels from carcasses, the apparatus comprising conveying means for conveying carcasses in succession to a removal station of the apparatus, each carcass being engaged with an individual gambrel which is suspended from an overhead conveyor skid, removing means for removing said gambrel from engagement with the skid, moving means for moving said gambrel whilst still engaged with said carcass to a predetermined position, clamping means for clamping a portion of said gambrel at said predetermined position and moving means for moving said clamping means relative to the carcass such that the opposite extremities of the gambrel are removed in turn from said carcass.

In the following more detailed description of the invention reference will be made to the accompanying drawings in which:- Figure 1 is a plan view of a portion of the removal station of the apparatus in the vicinity of the clamping means, and 201831 Figure 2 is a side elevational view of the arrangement shown in Figure 1.

The carcasses being of sheep or other animals are suspended, usually in a frozen state, from the two outside notches of gambrels engaging in the hind legs of the carcasses. The standard gambrel is of a substantially shallow W shape as can for example be seen in Figure 1 of the drawings. The gambrel is suspended from a skid having a hook with the central notch portion of the gambrel being located in the open hook of the skid. The skids are moved along a support rail by being engaged by lugs or other means of a moving drive chain located adjacent the support rail.

Initial orientation of the carcasses takes place so that the vertically hanging carcasses all travel sideways with one or other leg preceding the other. This initial orientation can be effected by using the arrangements disclosed for example in New Zealand Patent Specifications 190305/191115 or 194346. As the arrangement disclosed in Patent Specification 194346 uses the regular protrusions at the end of the closed over portions of the hook on their captive skid and bachelor gambrel as a means of facilitating the sensing of the orientation of the carcass to thus instigate (if necessary) any subsequent orientation, such an arrangement is not suitable where standard skids and standard gambrels are used primarily because of the irregularities in the height and width of the open point of the skid hook from a vertical central line. Accordingly a system 201831 such as disclosed in Patent Specification 190305/191115 is employed as this relies on the greater protruberance of the rump or hind quarter of a hanging carcass, rather than the opposite or belly side, to sense the orientation of the carcass. Accordingly as the carcass is moved along the supporting rail its orientation is sensed and moving means are activated (if necessary) so that for those carcasses where a preselected leg is not the leading leg they are rotated on the swivelling skid hook through 180°. All carcasses thereby end up travelling with one preselected side leading.

A subsequent further rotation through 90° is carried out so that all carcasses are fed in a uniform orientation (preselected belly or back first) into the gambrel removal station. This removal station can be at a point where the gambrel is removed from the carcass so that the carcass can be moved either to storage or for consignment. Alternatively the removal station can be at a point where the carcass is engaged by a further conveyor whereupon wrapping of the carcass can take place in the manner for example described in our New Zealand Patent Specifications 195874 and 196035.

Once carcass orientation has been completed the carcass moves to a point where the weight of the carcass bearing on the skid is eliminated. This is the first step in the separation of the gambrel from the skid and subsequent removal of the gambrel from the carcass. 6 201831 Movement of the carcass along the support rail is as previously stated achieved by the lugs or other means on the moving drive chain engaging the skids. It is, however, necessary to provide alternative propulsion means for the continued movement of the carcass through the system once the skid is disengaged from the gambrel. This alternative drive mechanism can for example be provided by two suitably located horizontal side conveyors on which the chain drives are fitted with sideways protruding lugs which engage the carcass from either side, preferably just beneath the hocks. These side conveyors can for example be of the type disclosed in Patent Specification 194346 and are fully synchronised with all other conveyors in the system. The side conveyors engage with and propel the carcass immediately after the final 90° orientation (already described) has taken place and thus move the carcass in its preselected belly first or back first progression through the removal station. The lugs which may be single or doubled up on either or both side conveyor chains have the added function of maintaining the carcass in its selected orientation in the manner described in the aforementioned Patent Specification 194346.

Once the side conveyors or other means of alternative propulsion have engaged the hocks or other part of the carcass the weight of the carcass can be removed from the gambrel and skid. In a preferred form, suitably positioned horizontal rails are located on the two side conveyor frames in a manner 201831 which allows the opposite facing points of the gambrel (which protrude outside the two hocks of the carcass) to engage with and ride along the rails to thereby provide support means for the carcass. This support means is suitable for use when a simple mechanical degambrelling operation is to take place. Where, however, the carcass is to be wrapped in accordance with the teachings of New Zealand Patent Specifications 195874 and 196035 the tines of the automatically height adjusted bagging conveyor are used to grip the carcass at its lower or neck end to provide alternative support means. The support provided by the bagging conveyor, however, can be used in combination with the aforementioned side support rails engaging with the gambrel points.

Once the carcass is suspended solely from the gambrel or tines of the bagging conveyor the skid rail can be sloped downwardly to an extent slightly greater than the depth to the point of the skid hook. This downward movement of the hook of the skid results in bearing contact between the gambrel and the skid being lost and the skid body being disengaged from the lug of the overhead driving chain. As the open side of the skid hook is usually positioned to face the belly of the carcass the continued forward movement of the carcass by means of the side conveyors permits the gambrel to also move forward over the open point of the lowered and now stationary skid hook to complete separation of the gambrel from the skid. A sideways curvature can be provided in the lowered skid rail and by the 8 20rsi i use of a sweep arm, or other means regulated to move in after a ♦ suitable delay and push the disengaged skid away before the arrival of the next skid, complete separation of the skid from the gambrel takes place at this point.

In those slaughter chains where the open end of the skid is routinely inserted to face to the back of the carcass instead of the belly the orientation of the carcass can be modified by altering the sensors so that the carcass enters the system back first. The gambrel and skid separation can then take place as described above.

As a further alternative the carcass orientation may be so regulated whether the open side of the skid is routinely facing to the belly or back of the carcass so that it is the open side of the skid hook which is trailing instead of leading. In this arrangement the lowering of the skid rail takes place with sufficient slope that the skid accelerates away under gravity or other means so that the open point of the hook moves under and ahead of the gambrel and the skid is then removed from the system as mentioned above.

Referring now to Figures 1 and 2 there is shown a gambrel 10 having two side notch portions 11 with end points 12. The central notch is indicated at 13. The points 12 are engaged on the aforementioned support nails 14 and immediately below the support rails 14 are situated the side conveyors 15.

Because the gambrel 10 is normally firmly frozen into the hocks of the carcass its removal is facilitated by breaking the 201831 ice bond between the notches 11 and the hocks. To break this ice bond the central upward facing notch 13 of the gambrel 10 is driven under a sloping overhead rail (not shown) which causes the gambrel to rotate backwards through 90° thus breaking the ice bond in the hocks. The rotation also causes the formerly upward sloping points 12 to face rearwardly such that the gambrel 10 is orientated as shown in Figure 1.

Since the gambrel could rotate further than 90° it is desirable to include the side supporting rails 14 irrespective of whether the aforesaid bagging conveyor is being used. With the points 12 of the gambrel 10 now being horizontal and pointing backwardly the weight of the carcass forward of the bearing points 12 provides a counter-rotational force which would once again raise the gambrel into its vertical orientation. This is prevented by continuing the central overhead rail (not shown) such that the gambrel 10 is maintained in its fully horizontal position thereby ensuring that the gambrel is presented at the right height and correct position to engage in clamping means 16.

The clamping means 16 are used to facilitate the final removal of the gambrel from the carcass. The clamping means 16 is carried on an overhead support arm 17 which is mounted at its upper end 18 into a jointed mechanism 19 capable of free movement and rotation in any direction. This freely pivoting support arm 17 allows the clamping mechanism 16 to move forward and compensate for the continued forward movement of the 201831 carcass by the side conveyors 15. It will be appreciated that the carcass is firmly held in position by the side rails 14. There is thus no interruption in the progress of the driving chains and associated lugs so that the carcass moves continuously. If the mechanical removal of the gambrel is being used as part of the wrapping system disclosed in New Zealand Patent Specifications 195874 and 196035 the bagging conveyor is fully synchronised with the movement of the side conveyors 15.

The jaws 20 of the clamping mechanism 16 have horizontally disposed V shaped slots 21 which are directed toward the approaching gambrel and are set at the appropriate height to receive a portion of the gambrel therein. These V shaped slots 21 terminate in a semi-circular notch 22 which has a diameter slightly greater than that of the gambrel. When the gambrel enters this notch 22 a wedge shaped tongue (not shown) is driven by a pneumatic cylinder (not shown) to firmly wedge and secure the gambrel in the jaws 20. A suitably placed microswitch controls the sequence of this operation.

The clamping action takes place immediately to one side of the central notch 13 of the gambrel 10 as can be seen in Figure 1. The reasons for this are that it is easier to grip the straight section of the gambrel but more particularly clamping in this position permits a greater sideways movement of the firmly held gambrel to allow the point 12 of the gambrel to be moved fully out of the hock of the carcass on the side on which 2.01 S3) the clamp 16 is fixed without this movement being restricted by the body of the clamp meeting the inside of the opposite hock.

The sideways movement of the clamp to extract the gambrel from the first hock is effected by an appropriately side mounted pneumatic cylinder 24. This sideways movement of the gambrel 10 out of the first hock results in the gambrel being pushed further through the second hock.

Because there is a risk that the reciprocal sideways movement of the clamp and gambrel required to free the gambrel from the second hock could result in the point of the gambrel on the newly freed side re-entering the same hole in that hock a further pneumatic cylinder 25 is used to rotate the clamping mechanism 16 and its mount arm 17 through approximately 20° so that the gambrel point 12 and freed hock are no longer in line. A further pneumatic cylinder 26 mounted on the opposite side of the clamp mechanism 16 deflects the clamp sideways to complete the extraction of the gambrel from the second hock.

A combination of return thrusts in the various cylinders of the pneumatic cylinders 24, 25 and 26 returns the clamp mechanism to its original position to receive the gambrel of the next carcass. This operation includes the retraction of the wedge holding the gambrel in the clamp which is therefore released and thrust sideways into a receiving chute (not shown) as a result of the returning momentum of the clamp mechanism 16. 201831 Since the degambreller of this invention is preferably able to work at speeds in excess of 30 carcasses per minute, split second timing is required for the sequence of pneumatic cylinder operations described above and to ensure that these operations remain compatible with the varying speeds at which the associated carcass conveying systems in the degambreller and orientation devices are operated. Although not necessarily essential an adjustable electronic timing system to control the speed and sequence intervals between each section of the operations is preferably incorporated.

If the orientation and degambreller of the invention are used as part of the wrapping system disclosed in New Zealand Patent Specifications 195874 and 196035 the carcass proceeds through the wrapping sequence once the gambrel has been removed. If, however, the orientation devices and degambreller are being used for conventionally wrapped or processed frozen carcasses, auxiliary chutes and belts or similar facilities (all not shown) are provided in the region beneath the clamping mechanism 16 to catch the carcasses as they fall clear after removal of the gambrel. 13 201831

Claims (31)

WHAT WE CLAIM IS

1. A method of mechanically removing gambrels from carcasses, the method comprising the steps of conveying carcasses in succession to a gambrel removal station, each carcass being suspended from an overhead skid of a conveyor by an individual gambrel, removing said gambrel from engagement with said skid, moving said gambrel such that a portion thereof is moved into a predetermined position, clamping a portion of said gambrel in clamping means and moving said clamping means relative to the carcass such that the two opposite extremities of the gambrel are removed in turn from said carcass.

2. The method according to claim 1 wherein the carcass is moved substantially continuously from the time it reaches the gambrel removal station until the gambrel is removed.

3. The method as claimed in claim 1 or 2 wherein said carcass is moved by conveying means which engage with the carcass.

4. The method according to claim 1, 2 or 3 wherein prior to the gambrel being removed from the skid the carcass is supported such that the weight thereof is not transferred through the gambrel to the skid.

5. The method as claimed in claim 4 wherein relative movement between the skid and the gambrel is caused to take place once the weight of the carcass has been removed from the skid.

6. The method as claimed in any one of claims 1 to 5 wherein relative movement between the gambrel and the carcass takes place during at least part of the movement of the gambrel into said predetermined position. 201831

7. The method according to any one of claims 1 to 6 wherein the carcass is orientated in a predetermined orientation prior to either the carcass being conveyed to the gambrel removal station or the skid being removed from the gambrel.

8. The method as claimed in any one of claims 1 to 7 wherein said clamping means are moved in a first direction relative to the carcass so as to remove a first portion of the gambrel from the carcass and then moved in a second direction substantially opposite to said first direction to effect complete removal of the gambrel from the carcass.

9. The method as claimed in claim 8 wherein the orientation of the clamping means is changed between said clamping means being moved in the first and second directions.

10. The method of claim 1 substantially as herein described, with reference to the accompanying drawings.

11. Apparatus for removing gambrels from carcasses, the apparatus comprising conveying means for conveying carcasses in succession to a removal station of the apparatus, each carcass being engaged with an individual gambrel which is suspended from an overhead conveyor skid, removing means for removing said gambrel from engagement with the skid, moving means for moving said gambrel whilst still engaged with said carcass to a predetermined position, clamping means for clamping a portion of said gambrel at said predetermined position and moving means for moving said clamping means relative to the carcass such that the opposite extremities of the gambrel are removed in turn from said carcass. 201831

12. Apparatus as claimed in claim 11 further including supporting means for supporting said carcass.

13. Apparatus as claimed in claim 12 wherein the supporting means is a pair of support surfaces which are engagable by the outermost extremities of the gambrel.

14. Apparatus as claimed in claim 12 wherein the supporting means is a supporting conveyor adapted to engage with a lower portion of the suspended carcass.

15. Apparatus as claimed in claim 12 wherein the supporting means is support surfaces for engaging with the outermost exirovii hes oittromoitieq of the gambrel and a supporting conveyor for engaging with a" lower portion of the suspended carcass.

16. Apparatus as claimed in any one of claims 11 to 13 further including carcass moving means formed by at least one conveyor which engages with an upper portion of the carcass.

17. Apparatus as claimed in claim 14 or 15 wherein said supporting conveyor also functions to provide carcass moving means.

18. Apparatus as claimed in any one of claims 11 to 17 further including an orientation means conprising an engagement surface which is engagable with said gambrel to move said gambrel into said predetermined position there being limiting means to limit movement of the gambrel beyond said predetermined position. - 16 - ) 201831

19. Apparatus as claimed in claim 18 when /ippuiiJeHL directly or indirectly to claims 13 and 15 wherein the limiting means is the support surfaces of the support means.

20. Apparatus as claimed in any one of claims 12 to 19 wherein the removing means is formed by the rail of the overhead conveyor having a slope relative to the supporting means such that a relative movement between the skid and the carcass results.

21. Apparatus as claimed in claim 20 further including skid engagement means for engagement with a skid separated from the gambrel.

22. Apparatus as claimed in any one of claims 11 to 21 wherein the clamping means is formed by jaws having openings which are directed toward an approaching gambrel and are orientated to receive a portion of the gambrel when in said predetermined position, said jaws further including wedging means to wedge a gambrel within said jaws.

23. Apparatus as claimed in claim 22 wherein said slots are of substantially V shape with a semi-circular notch in the apex thereof, said notch having a diameter slightly greater than that of the portion of the gambrel to be located therein.

24. Apparatus as claimed in claim 22 or 23 wherein said wedge is operated by a linear actuator.

25. Apparatus as claimed in any one of claims 11 to 24 wherein said clamping means is suspended by movable suspension means. 17 201831

26. Apparatus as claimed in claim 25 wherein said suspension means is an overhead support arm mounted at its upper end by a mechanism capable of free movement and rotation such as to enable the clamping means to move with the continued movement of the carcass.

27. Apparatus as claimed in any one of claims 11 to 26 wherein said moving means for moving said clamping means is a pair of linear actuators operable to move said clamping means such that a gambrel clamped with said clamping means is movable in two substantially opposite directions.

28. Apparatus as claimed in claim 27 further including means for rotation of said clamping means relative to the longitudinal axis of the gambrel.

29. Apparatus as claimed in claim 28 wherein said rotating means is a linear actuator.

30. Apparatus as claimed in any one of claims 24, 27 and 29 wherein the linear actuators are pneumatic rams.

31. Apparatus for removing gambrels from carcasses substantially as herein described with reference to the accompanying drawings. THE MEAT INDUSTRY RESEARCH INSTITUTE OF NEW ZEALAND INCORPORATED By Their Attorneys Per: 18 t^