BACKGROUND The process of manually removing meat from whole carcasses requires skill and judgement in the manipulation of both meat and tools to achieve satisfactory results. Shortages of skilled labour, and an increasing demand for meat processors to reduce prices whilst improving quality and safety, has resulted in an increasing trend towards automation.

It is known to process a digital image of a meat carcass by means of a computer to automatically determine the best positions at which to make machine cuts, e. g. using a bandsaw. However, such systems are only capable of making very generalised machine cuts without any degree of precision, and a large amount of manual work is still required to produce good quality cuts of meat. The present invention seeks to provide a new and inventive form of carcass cutting apparatus which reduces the amount of skilled manual work required and improves the speed and quality of processing meat carcasses.

SUMMARY OF THE INVENTION The present invention proposes carcass cutting apparatus which includes : -a carrier system for continuously moving prepared meat carcasses from a loading position to an unloading position; -optical sensing means for detecting the size and position of the meat carcasses during movement along the carrier system ; and -a cutter which is carried and moved by a mechanical robotic arm under the control of a computer in response to information provided by the optical sensing means whereby the carcass is cut whilst in motion.

The use of a computer-controlled robotic arm allows the cutter to assist in guiding the meat carcasses during movement without the need to stop and hold the carcasses during the cutting process. The speed of the cutting process is therefore significantly increased.

The arm will generally be arranged to move the cutter in three mutually orthogonal axes with provision for changing the orientation of the cutter relative to the carcass.

The cutter is preferably of the kind having a cutting edge which moves in a continuous path, e. g. a circular saw blade. In order to permit the blade to be correctly orientated for making the necessary cuts the blade may be mounted for rotation under control of the computer about a substantially diametrical axis.

The apparatus may include support means for providing support for the carcass during the cutting procedure. The support means may comprise a fixed wall or bars, or a moving belt, rollers or the like.

The carrier system preferably includes a series of suspension elements for suspending the carcasses therefrom.

The invention also provides a method of cutting prepared meat carcasses which includes: -continuously moving prepared meat carcasses from a loading position to an unloading position; -optically sensing the size and position of the meat carcasses during movement; and -cutting the carcasses whilst in motion using a cutter which is carried and moved by a mechanical robotic arm under the control of a computer in response to the optical information.

The prepared carcasses are preferably suspended with the head end down.

The first cut is preferably made longitudinally of the carcass, i. e. a chop or loin cut, and preferably in an upward direction. This may be followed by one or more transverse cuts made generally in the direction of movement, e. g. a ham cut. Making the cuts in the order specified ensures the accuracy of the cuts.

BRIEF DESCRIPTION OF THE DRAWINGS The following description and the accompanying drawings referred to therein are included by way of non-limiting example in order to illustrate how the invention may be put into practice. In the drawings: Figure 1 shows a prepared carcass with the position of various standard cuts marked thereon ; Figure 2 is a front view of meat carcass cutting apparatus in accordance with the invention; and Figure 3 is a plan view of the apparatus.

DETAILED DESCRIPTION OF THE DRAWINGS Fig. 1 shows a half-side of pork C looking from the bone side. The position of the spinal column is indicated at S. The carcass is orientated as it would be when suspended from the tail end with the head end downmost. The various primal cuts are shown in the drawing as follows : L: Chop or loin cut H: Ham cut B : H-bone cut D : Shoulder cut The apparatus to be described below can be used for hot, warm or cold processing of carcasses (i. e. post-slaughter, room temperature or chilled processing). The chop or loin cut is invariably made, but the number of transverse cuts (e. g. H, 8 and D) can vary.

Referring to Fig. s 2 and 3, the carcass cutting apparatus includes a track 1 for conveying the meat carcasses C from a loading end 2 to an unloading end 3. The track includes chains or similar means suitable for carrying the meat carcasses one after another, at a constant known speed, suspended from hooks in the head-end-down orientation shown in Fig. 1. The carcasses are loaded onto the track 1 with the skin side facing a guide and support wall 4 which extends along the rear of the track. The wall 4 maintains the orientation of the carcasses which are substantially aligned in their direction of movement along the track 1.

As shown in Fig. 3, the apparatus includes a cabinet 5 which contains a computer for data processing and control. There is also a motorised robot 7 having a robotic arm 8 which comprises two or more relatively moveable sections. The arm carries a rotatably driven circular saw blade 11 and is arranged to move the blade in three mutually orthogonal axes (i. e. cartesian X, Y and Z axes). Orientation of the blade is also possible by controlled rotation about a horizontal axis which extends diametrically of the blade. The robot 7 is a standard industrial unit which is completely encased within a liquid-impermeable jacket (not shown) except for the blade 11.

An optical system comprising a CCD camera 20 is arranged between the loading position 2 and the robot 7 to obtain a digital image of the carcass as viewed from the bone side which faces away from the wall 4. The computer analyses the digital image to determine the best positions in which to make the primal cuts according to the size and shape of the carcass. The robot is then directed to cut the carcasses as they move along the track 1 according to a cutting pattern determined by the computer. The direction and order of the cuts is important. The first cut to be made is the chop or loin cut L (Fig.

1) which can be made in an upward or downward direction. During cutting the blade 11 also moves with the carcass along the track 1 so that the blade helps to guide the carcass along the track, assisted by the fact that the carcass is also supported and guided by the wall 4.

The first cut L is followed by the ham cut H, which is made from right to left as viewed in Fig. 1. This can be followed by the H-bone and Shoulder cuts B and D, which are made in the same direction. The cuts are made very rapidly. The position of the cutter 11 at the start and end of the cutting process is illustrated at N and M in Fig. s 2 and 3. Fig. 2 also illustrates the upper and lower limits of required range of movement, N and P.

The cut carcass is removed from the track at the unloading end 3. The final removal of the meat will usually be performed manually, although the apparatus can be programmed to perform complete through-cuts or partial through-cuts if desired. The precise control over the cutting depth and position which is possible using the visual analysis and robotic cutter allows the meat and soft tissues to be accurately cut whilst still held together by the bony skeleton. Alternatively, the computer can be programmed to cut through the skin and bone so that the carcass only remains held together by skin.

The total processing time from input of the carcass to output of the cut products may be significantly less than that required for total manual processing, depending on the number of cuts required. The apparatus thus has benefits for the processing plant in terms of increased productivity, more consistent quality, higher yield, better hygiene and improved working conditions.

It will be appreciated that the features disclosed herein may be present in any feasible combination. Whilst the above description lays emphasis on those areas which, in combination, are believed to be new, protection is claimed for any inventive combination of the features disclosed herein.