CARCASS KNUCKLE TIPS

FIELD OF THE INVENTION

This invention relates to a method and apparatus for the removal of the knuckle tip from the hind-leg or fore-leg of an animal carcass.

TERMINOLOGY

Where the following terms are used in this specification they shall have the following meanings:

• Carcass: where the term carcass is used, this means either a whole carcass or a carcass portion, e.g. a hindquarter. • Knuckle: the leg joint at the outer end of the hind-leg or fore-leg of an animal carcass.

• Knuckle Tip: the portion of knuckle removed from a carcass for reasons of hygiene and appearance. The knuckle tip is a waste product.

BACKGROUND OF THE INVENTION

In a typical meat processing facility, animal carcasses are separated into a variety of portions - both saleable cuts and waste portions - by means of knife or saw. Sawing is commonly used where there is bone to cut as it is impossible to cut this manually with a knife. Recently a number of circular powered knives have been developed which give the improved yield of a knife cut through both flesh and bone. However, use of such knives is limited to soft bone, and is therefore dependant on animal species, age and portion of the carcass. Consequently there are still a number of processing areas in which saws - particularly handsaws - are used. Sawing with a bandsaw is known to be a dangerous occupation within the meat industry, where the cold of the environment combined with production pressure and worker fatigue contribute to a high level of accidents. A number of automated solutions are now becoming available for areas within the meat industry, such as those produced by Robotic Technologies Ltd (e.g. NZ 540749). However, such equipment is not appropriate for every meat processing operation.

The exposed end of the knuckle on the fore-leg and the hind-leg is an area of high bacteria risk, and the knuckle shape is not seen as desirable to the product appearance. It is therefore common practice to remove the knuckle tip by cutting it off in a bandsaw. This represents one of the most dangerous sawing areas in the meat processing industry as the processing is very fast, and to achieve the required accuracy operators must have their hands very close to the bandsaw. To-date there has been no alternative to the bandsaw for this operation.

One system which is used for automatically removing the hock from an animal carcass within a meat processing slaughterboard operation exposes the end of the knuckle, and is therefore very similar in principle to the knuckle tip cut. In this apparatus, the carcass is suspended from a conveyor by a clamp on each hock. The conveyor then transports the carcass past a saw such that the hock is removed. The position of the hock in the clamp is not controllable, and thus there is limited consistency in the position of the cut. The knuckle tip cut however must be positioned accurately to produce a finished product with the best possible appearance while minimizing the loss of saleable yield. In this system, the hock remains clamped to the conveyor after the cut has been performed, and a further mechanism or manual operation is required to remove the hock from the conveyor. Loading of the system is also dangerous, as operators are required to load the legs of the carcass onto a moving conveyor thus exposing them to the risk of entrapment.

It would be desirable to provide a knuckle tipping system which removes the knuckle tip from the carcass in a manner which does not endanger the operator, is affordable so that its use can be widespread, and its operation automatically and accurately selects the correct position to cut or at least provide the public with a useful choice.

STATEMENTS OF INVENTION

According to one exemplary embodiment there is provided a method of removing a knuckle tip from a leg of an animal carcass comprising the steps of: i. engaging a narrow section of the leg proximal to the knuckle tip between guide faces of a guide spaced apart a predetermined distance for a desired knuckle tip cut for a desired species; and ii. moving the leg relative to a cutter whilst the guide maintains the leg a predetermined distance from the cutter so as to cut off the knuckle tip at a desired location.

The guide may be in the form of a pair of spaced apart guide rails where the spacing between the guide rails may be adjusted to perform a desired knuckle tip cut for a desired species (preferably a rail spacing of between

20mm to 35mm and an offset from the guide faces to the cutter of between 10 mm to 25 mm for lamb or mutton). The leg may be pushed along the guide rails into the cutter. The leg may be loaded onto the guide rails by pushing the knuckle end of the leg through a gateway where the opening and closing of the gate is controlled by the movement of the leg being inserted or by pushing the knuckle end of the leg through a gateway where the gate is controlled to open when the leg is in close proximity to it. A gate may be opened to allow a leg to be loaded by means of activation of a mechanical lever or electronic switch or other actuation device. Alternatively the leg may be loaded by sliding it onto the guide rails at an end of the guide rails.

The guide may also be in the form of a pair of opposed belts that grip and advance the leg towards the cutter. The leg may be introduced at a location where the belts converge such as where at least one belt rounds a drive pulley.

The guide may also be in the form of a trolley which runs along a rail including a plurality of jaws having guide faces which engage the leg proximal to the knuckle tip.

In another embodiment the guide adjusts the position of the cutter relative to the leg. The guide may be in the form of a pair of spaced apart guide rails that diverge at their distal ends where the leg is introduced.

According to another exemplary embodiment there is provided a knuckle tip removal device for use in a meat processing operation including two parallel guide rails spaced apart such that a leg of a carcass may be located in the gap between the guide rails with a knuckle of the leg located on the top of the guide rails, a product loading region where a leg may be loaded onto the guide rails and a cutter positioned in relation to the guide rails such that the knuckle tip of a leg is cut from the leg by the cutter as a leg is advanced along the guide rails.

The cutter may cut in a plane parallel to the guide rails. The gap between the two guide rails may be adjustable to achieve the desired knuckle tip removal position for the species of carcass that is being processed (preferably the gap between the two guide rails in the range of 20 mm and 35 mm and the offset between the plane of the guide rails and the cutter in the range of 10 mm to 25 mm).

The product loading region may consist of a hinged gate in the guide rails, such that pushing the gate with the knuckle end of the leg causes the gate to open, thus creating a gap large enough to allow the knuckle to slide past the gate, allowing the gate to then move back into the closed position or the loading region may consist of a gate in the guide rails which opens when a leg is in close proximity to it. Alternatively the loading region may consist of a gate in the guide rails which opens when the operator activates a mechanical lever or electronic switch or other actuation device or legs may be loaded by sliding them between the guide rails at an open in-feed end.

The knuckle tip removal device may be configured such that as soon as a knuckle tip is cut from a leg, neither the leg nor the knuckle tip remains supported and they are free to drop. The cutter may be a rotating circular blade or a bandsaw.

In one embodiment the guide rails may be in the form of two spaced apart belts that may be driven such that a leg of a carcass may be located in the gap between the belts with a knuckle of the leg located on the top of the belts.

According to another exemplary embodiment there is provided a knuckle tip removal device for use in a meat processing operation including a trolley having a plurality of spaced apart jaws such that a leg of a carcass may be located in the gap between the jaws with a knuckle of the leg located above the jaws, a guide rail along which the trolley may be advanced and a cutter positioned in relation to the guide rail such that the knuckle tip of a leg is cut from the leg by the cutter as a leg is advanced along the rail.

According to another exemplary embodiment there is provided a knuckle tip removal device for use in a meat processing operation including a guide rail along which a leg may be advanced and a cutter having a guide having a tapering slot engageable with the leg which adjusts the spacing of the cutter with respect to the rail such that the knuckle tip of a leg is cut from the leg by the cutter as a leg is advanced along the guide rail.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings which are incorporated in and constitute part of the specification, illustrate embodiments of the invention and, together with the general description of the invention given above, and the detailed description of embodiments given below, serve to explain the principles of the invention.

■ Figure 1 shows a general view of a knuckle tip removal device.

Figures 2a to 2c show detailed orthogonal views of the knuckle tip removal device shown in figure 1.

Figure 3 shows a typical cross-section through the transporting region.

Figure 4 shows a typical cross-section through a loading region in which a leg is being loaded.

Figure 5 shows a cross-section through the cutting region in which the knuckle tip is being cut from a leg. Figures 6a and 6b show details of where the knuckle tip removal cut should ideally be made.

Figure 7 shows a plan view of a knuckle tip removal device utilizing a pair of belts as the guide rails.

Figure 8 shows a plan view of a cutter incorporating a guide.

Figure 9 shows a side view of the cutter shown in figure 8 engaging a leg.

Figure 10 shows a trolley for engaging a leg of a carcass.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Referring to Figures 1 to 2c, a knuckle tip removal device is shown. The device would typically be raised from the ground level to allow workers to comfortably work in the region from the processing tables 14 to the loading regions of the device 1. Legs 4 are loaded into the device at any of the loading regions 1 along the length of the transporting region 2. The covers 10 provide the operators with a measure of security from contact with moving mechanical components. When a leg 4 is loaded, it is then transported along the transporting region 2 until it reaches the cutting region 3, whereupon the knuckle tip is cut from the leg 4 and the knuckle tip and leg 4 are free to drop from the device.

Figure 3 shows a leg 4 sitting in the transporting region 2 of the device. The leg 4 sits such that it protrudes through the gap between the two edges 6 of guide rails 14 and 15, and the knuckle sits on the top of the edges 6 to prevent the leg 4 from falling out. The leg 4 is transported along the length of the transporting edges 6 by being pushed by a pusher 8 from one loading region to the next. The pusher 8 is mounted in the carriage 7, which travels along the inside of the device cover 10. The pusher 8 is inclined and free to pivot in the carriage 7 thus allowing it to lift up as it makes contact with a leg 4 on its retraction cycle, but stays down under the influence of gravity during its forward stroke.

In figure 4, a leg 4 is being loaded into the device at one of the loading regions 1. Flaps 16 and 17 are hinged with respect to guide rails 14 and 15 to form a gate 5. By pushing the knuckle end of the leg 4 into the gate 5, the flaps 16 and 17 open upwards. As the flaps 16 and 17 open, the gap between them increases until it is wide enough for the knuckle of the leg 4 to pass between them. Once the knuckle has cleared the flaps 16 and 17, they are free to fall under gravity back to the transporting position. Similarly, the flaps 16 and 17 could be pushed back to the transporting position by a spring or other powered device. When the operator releases the leg 4, it will drop back down until the knuckle is resting on the transporting edges 6, thus referencing the height of the knuckle. An alternative loading method is to simply slide the leg onto the in-feed end of the transporting edges 6. However, this method is only possible for one operator, and it is therefore necessary to have the alternative loading regions 1 to allow for multiple operators.

Figure 5 illustrates the cutting principle of the device. The last pusher 8 pushes the leg 4 into the cutting blade 9 in the cutting region 3. The knuckle tip 11 is thus cut from the leg 4. As it is no longer held, the leg 4 is free to drop. Similarly, the knuckle tip 11 is resting unrestrained on the cutting blade 9 and is free to drop off the side of the blade as the blade continues to spin.

Figures 6a and 6b show the position on the leg 4 where the knuckle tip 11 is intended to be cut from the leg 4. Figure 6b shows the cross-section A-A of the leg 4 through the ideal cut position. The intention is to have a small amount of muscle 13 either side of the leg bone 12. If the cut is too far down the leg 4, the processor will lose an excessive amount of saleable yield. Conversely if the cut is too far up the leg 4, the appearance of the cut is not acceptable to the market. It has been found that the approximate cutting position can be located by resting the knuckle on two edges with a predetermined gap between the edges, and cutting at a predetermined height relative to the edges. Figure 3 illustrates that for lamb and mutton, the ideal gap "g" between the edges 6 is in the range of 20 to 35mm, with a related height between the edges 6 and the cutting blade 9 with height "h" in the range of 10 to 25mm as illustrated in figure 5. While this is not an exact measure of the ideal cutting position, it is typically more accurate than is achieved manually, and is significantly less expensive than a system which uses sophisticated sensing and machine adjustment to cut at the exact position.

Figure 7 shows a plan view of a further embodiment in which guide rails 14 and 15 are replaced by belts 18 and 19 driven around drive rollers 20 to 23 which advance the belts. A leg 24 may be introduced at one end so that the knuckle tip 25 sits on top of the belts 18 and 19 and is advanced towards circular cutter 26 by the belts to cut off the knuckle tip, whereafter the leg and knuckle tip are free to fall away.

Figures 8 and 9 show another embodiment in which a leg 27 hangs from a conventional rail 28 by a conventional trolley 29 and is advanced towards a circular blade 30, the height of which is vertically adjustable. A guide associated with the circular blade has a pair of legs 32 and 33 defining a tapering slot between them. As the leg is advanced into the tapering slot the height of the circular blade is adjusted to cut off the knuckle tip at the desired height. Referring now to figure 10 there is shown an embodiment in which a trolley 34 has a pair of hinged flaps 35 and 36, similar in operation to flaps 16 and 17 previously described. A knuckle tip may be introduced through flaps 35 and 36 and then released so that the leg will then be held by the knuckle tip resting on top of the flaps 35 and 35 when flat. The leg may then be advanced towards a cutter as in the previous examples t remove the knuckle tip.

While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of the Applicant's general inventive concept.