GB2302008A

GB2302008A - Trimming surplus fat from meat

Info

Publication number: GB2302008A
Application number: GB9512073A
Authority: GB
Inventors: David Henry Lloyd Maunder; Graham Purnell
Original assignee: LLOYD MAUNDER Ltd
Current assignee: LLOYD MAUNDER Ltd
Priority date: 1995-06-14
Filing date: 1995-06-14
Publication date: 1997-01-08
Anticipated expiration: 2015-06-14
Also published as: GB9512073D0; GB2302008B

Abstract

Equipment for trimming surplus fat from a cut of meat (C) comprises an abutment wall (10) for engagement by the outer surface of a fat layer on the cut of meat (C), and a cutter (2) which, in operation, moves along a cutting path (8) extending along the fat layer. Control means are provided for varying the distance between the abutment wall (10) and the cutting path (8) along the length of the cutting path (8). By appropriate variation of the distance between the abutment wall (10) and the cutting path (8), the fat left on the cut of meat (C) can be brought close to the desired thickness.

Description

TRIMMING SURPLUS FAT FROM MEAT This invention relates to the trimming of surplus fat from cuts of meat.

Individual cuts of meat differ considerably from one another. In the case of lamb chops, for example, the thickness of the fat layer can differ greatly between chops taken from different animals. Even chops taken from the same animal can have different thicknesses of fat layer.

Supermarket chains are applying increasing pressure on their suppliers to achieve product uniformity. In the case of lamb chops, the requirement is for the fat layer to have a thickness, over its entire length, of approximately 5mm. This means that the supplier must trim surplus fat from each chop.

Until now, this has been done manually, and the job of trimming the fat is unpleasant and difficult to perform rapidly and accurately.

According to the present invention, there is provided equipment for trimming surplus fat from a cut of meat, the equipment comprising an abutment wall for engagement by the outer surface of a fat layer on the cut of meat, and a cutter which, in operation, moves along a cutting path extending along the fat layer, control means being provided for varying the distance between the abutment wall and the cutting path along the length of the cutting path.

By appropriate variation of the distance between the abutment wall and the cutting path, the fat left on the cut of meat can be brought close to the desired thickness.

The cutting path may be of a predetermined shape.

In a preferred embodiment in accordance with the present invention, the cutting path is arcuate. The variation in the distance between the abutment wall and the cutting path is achieved by making the abutment wall of variable configuration. The control means then varies the configuration of the abutment wall for each meat portion to provide the desired thickness of fat layer. The abutment wall may, for example, be made from a flexible material, such as strip steel, controlled by actuators which adjust the position of the abutment wall at different positions along its length.

Alternatively, the abutment wall can have a fixed configuration, in which case the control means acts on the cutter to move it along a cutting path which is determined on the basis of the thickness of the fat layer at different positions along its length.

The cutter is preferably a blade.

The equipment may comprise positioning means for pressing the meat portion against the abutment wall so that the full length of the outer surface of the fat layer engages the abutment wall.

The control means may be responsive to means for determining the thickness of the fat layer. In a preferred embodiment, the means for determining the fat thickness comprises a machine vision system such as an image scanner and processing circuitry which is capable of determining the distance between the outer surface of the fat layer and the interface between the fat layer and lean meat. The system may, for example, be adapted to determine the fat thickness at a plurality of locations along the fat layer.

The present invention also provides a machine for processing a cut of meat, the machine including a plurality of stations, and including equipment for trimming surplus fat as defined above.

According to another aspect of the present invention, there is provided a method of trimming surplus fat from a cut of meat, the method comprising the steps: engaging the outer surface of a fat layer on the cut of meat with an abutment; and passing a cutter through the fat layer along a cutting path, the distance between the abutment and the cutting path varying along the length of the cutting path.

For a better understanding of the present invention, and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 shows a lamb chop; Figure 2 shows a different lamb chop; Figure 3 shows, in diagrammatic form, the chop of Figure 1 installed in equipment for trimming surplus fat; Figure 4 shows a processing machine including the equipment of Figure 3; Figure 5 shows an alternative form of processing machine; Figure 6 shows a third form of processing machine; and Figure 7 shows a fourth form of processing machine, including modified fat trimming equipment.

In the Figures, lean meat is represented by crosshatching, bone is represented by single line diagonal hatching, and areas of fat are shown unhatched.

The chops shown in Figures 1 and 2 are typical of a chump chop (Figure 1) and a cutlet (Figure 2). They are taken from the same carcass, but it will be appreciated that they have different patterns of fat coverage from each other.

The difference in fat thickness also varies considerably from animal to animal and, as can be appreciated from Figures 1 and 2, the fat thickness varies along the length of the chop. For example, the fat thickness in the region of an arrow A in Figure 2 is significantly less than that in the region of the arrow B.

To be acceptable to major retailers, such as supermarket chains, the fat cover on a cut of meat such as a lamb chop must be substantially uniform from chop to chop and over the length of each chop. The preferred thickness of the fat cover is 5mm. The desired fat thickness in the chops shown in Figures 1 and 2 is indicated by dashed line X. To meet the requirements of the retailers, the surplus fat beyond the line X must be trimmed off. It is difficult to perform this trimming operation accurately by hand, yet inadequate trimming can lead to the meat being rejected by the retailer. Furthermore, since meat is sold by weight, trimming off too much fat can reduce the financial returns made by the meat supplier.

Figure 3 illustrates the principle of equipment for trimming the surplus fat from a lamb chop in a fast and accurate manner. The equipment comprises a cutter in the form of a trimming knife 2 mounted on a radius arm 4 which is pivotable about a pivot point 6. The radius arm 4 is powered, so as to drive the trimming knife 2 along an arcuate cutting path 8.

Situated just outside the cutting path 8 is an abutment wall 10. The abutment wall 10 is made from a relatively thin, flexible material, such as strip steel.

The abutment wall 10 is acted upon by a plurality of actuators indicated diagrammatically by arrows 12.

Further actuators, indicated by arrows 14, act in the direction towards the abutment wall 10 from its inner surface and, as can be appreciated from Figure 3, the actuators 14 serve to press a chop C (which is the chop shown in Figure 1) against the abutment wall 10.

In the processing of a chop to remove surplus fat, the chop is first assessed to determine how much fat should be removed from each portion along its length.

This assessment can be performed in several different ways, but a preferred arrangement is for the chop to be pictured by an image scanning device such as a TV camera. The resulting image is then processed to determine the thickness of fat at different locations.

For example, the fat thickness may be determined at the locations a to f in Figure 1. From the measured thickness at each location a to f is then subtracted the desired fat thickness (5mm) and the resulting difference measurement is then applied to the respective actuators 12 to cause the abutment wall 10 to be displaced away from the cutting path 8 by the respective distance measurement. The resulting configuration of the abutment wall 10 is shown in Figure 3.

The chop C is placed with the outer surface of the fat layer in contact with the abutment wall 10 and is pressed firmly into position by means of the actuators 14. This causes the chop to be deformed, the intention being that the desired thickness line X shown in Figure 1 lies as close as possible to the cutting path 8 of Figure 3. Consequently, operation of the trimming knife 2 results in the correct amount of fat being trimmed from the chop along its length to leave the desired thickness of fat covering on the lean meat.

It will be noted that, at the location d in Figure 1, there is no lean meat, and consequently, unless an adjustment is made, a very large fat thickness measurement will be obtained. The image processing equipment is preferably adjusted so that a fat thickness measurement above a predetermined level results in a default measurement being applied to the appropriate actuator 12.

Figure 4 shows a processing line including the equipment diagrammatically represented in Figure 3. In the processing line of Figure 4, individual chops are loaded onto pallets 16 for transfer through the process. At a loading station L, each pallet 16 receives an individual chop, positioned in an approximate orientation. The pallet 16 moves to an orientation station 0 at which the chop is aligned by external positioning devices 18. The pallet 16 then moves to a scanning station S at which an XY machine vision appraisal is made by means of an image scanning device 20. The scanned image is processed to determine the fat thickness and the amount to be trimmed, and this information is then fed to the actuators 12 at a trimming station T.When the pallet 16 is at the trimming station T, it is held in position against the abutment wall 10 by the actuators 14, and the trimming knife executes a cutting stroke along the cutting path 8. Finally, the pallet 16 moves to a discharge station from which the chop is removed for further processing or packaging.

In the alternative arrangement shown in Figure 5, the sequence of operations takes place in a similar fashion but is performed on a rotary carousel. The chop is introduced to the machine at a loading station L at which there is a conformable fixture 18 for aligning the chop. The chop remains held in the fixture 18 during its subsequent passage through the machine. At a scanning station S, the fat thickness is assessed by means of image sensing equipment 20 and the appropriate information is fed to a trimming station T at which, as with the embodiment of Figure 4, the chop is conformed to the shape of a variable abutment wall for trimming. A trimmed fat separator 22 is provided for detaching the trimmed fat and ejecting it for separate processing or disposal.

At the trimming station T, the trimming knife moves along the cutting path 8 in the direction opposite to that of indexing rotation. As the table rotates to carry the chop to the discharge station D, the trimming blade is rotated back to its start position. At the discharge station, D, the chop is ejected from the machine.

In the machine shown in Figure 6, the chop is moved by a drive belt 24. The drive belt conveys the chop C around an arcuate, almost semi-circular, path.

The chops are maintained against the drive belt 24 by a compliant inner wheel 26 which rotates in synchrony with the movement of the drive belt 24. The path of the outer drive belt 24 is defined by a series of servo controlled radial adjusters 28. The chop is moved past a thickness measurement sensor 30 and a line scan camera 32. The thickness measurement sensor determines the thickness of the chop which is used to determine the scaling used for analysis of the line scan image obtained from the camera 32.

At the trimming station, one of the radial adjusters 28 (designated 28' in Figure 6) is displaced radially in accordance with the fat thickness measurements obtained from the line scan image, in order to displace the chop as it encounters the knife 2, and during passage of the knife 2 through the fat layer, so as to trim the required thickness of surplus fat from the chop. Thus, in this embodiment, the trimming knife 2 remains stationary, the cutting motion being achieved by displacement of the chop as it is circulated by the belt 24. The belt itself serves as the abutment wall, the distance between the abutment wall and the path of the knife 2 through the fat layer being controlled by the radial adjuster 28'.

After trimming is complete, the trimmed fat and the chop are ejected from the machine at the discharge station D.

In the embodiment shown in Figure 7, the movement of each chop through the machine is broadly similar to that shown in Figure 6. However, in the embodiment Figure 7, the path of the outer belt 24 is fixed, and it is the trimming knife 2 which is displaced radially, as the chop moves past it, to vary the distance between the abutment wall, formed by the belt 24, and the trimming knife 2.

Although the present invention has been described with specific reference to lamb chops, the same principles can be applied to the trimming of surplus fat from other cuts of meat, such as pork chops and sirloin steaks.

Claims

1. Equipment for trimming surplus fat from a cut of meat, the equipment comprising an abutment wall for engagement by the outer surface of a fat layer on the cut of meat, and a cutter which, in operation, moves along a cutting path extending along the fat layer, control means being provided for varying the distance between the abutment wall and the cutting path along the length of the cutting path.

2. Equipment as claimed in claim 1, in which the cutting path is arcuate.

3. Equipment as claimed in any one of the preceding claims, in which the variation in the distance between the abutment wall and the cutting path is achieved by making the abutment wall of variable configuration, the control means varying the configuration of the abutment wall for each meat portion to provide the desired thickness of fat layer.

4. Equipment as claimed in any one of the preceding claims, in which the abutment wall is made of a flexible material controlled by actuators which adjust the position of the abutment wall at different positions along its length.

5. Equipment as claimed in claim 4, in which the flexible material comprises steel strip.

6. Equipment as claimed in any one of claims 1 to 3, in which the abutment wall has a fixed configuration, the control means acting on the cutter to move it along a cutting path which is determined on the basis of the thickness of the fat layer at different positions along its length.

7. Equipment as claimed in any one of the preceding claims, in which the cutter is a blade.

8. Equipment as claimed in any one of the preceding claims, further comprising positioning means for pressing the meat portion against the abutment wall so that the full length of the outer surface of the fat layer engages the abutment wall.

9. Equipment as claimed in any one of the preceding claims, in which the control means is responsive to means for determining the thickness of the fat layer.

10. Equipment as claimed in claim 9, in which the means for determining the fat thickness comprises a machine vision system which is capable of determining the distance between the outer surface of the fat layer and the interface between the fat layer and the lean meat.

11. Equipment as claimed in claim 10, in which the machine vision system is adapted to determine the fat thickness at a plurality of locations along the fat layer.

12. A machine for pressing a cut of meat, the machine including a plurality of stations and including equipment for trimming surplus fat as claimed in any one of the preceding claims.

13. A method of trimming surplus fat from a cut of meat, the method comprising the steps of: engaging the outer surface of a fat layer on the cut of meat with an abutment; and passing a cutter through the fat layer along a cutting path, the distance between the abutment and the cutting path varying along the length of the cutting path.

14. Equipment for trimming surplus fat from a cut of meat substantially as described herein, with reference to and as shown in Figures 1 to 4, Figure 5, Figure 6 or Figure 7 of the accompanying drawings.

15. A method of trimming surplus fat from a cut of meat, substantially as described herein, with reference to Figures 1 to 4, Figure 5, Figure 6 or Figure 7 of the accompanying drawings.