NZ204013A - Opening up carcass using circular saw which follows contour of brisket: viscera removal - Google Patents

Description

204013 N.Z. PATENT OFFICE 2 6 JUL 1984 BECEIVE3 N.Z.No. 204013 27 April 1983 NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION "IMPROVEMENTS IN OR RELATING TO METHODS AND MEANS FOR OPENING ANIMAL CARCASSES FOR VISCERA REMOVAL." We, THE MEAT INDUSTRY RESEARCH INSTITUTE OF NEW ZEALAND INCORPORATE an incorporated company organised 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 : - 204013 This invention relates to a method and means for opening animal carcasses for viscera removal.

During the dressing of carcasses of sheep, goats, calves, pigs, cattle and deer it is essential that the internal viscera (i.e. heart, lungs, trachea, diaphragm, kidneys, liver, spleen and the complete digestive system) be removed from the body cavity of the carcass quickly, efficiently and hygenically. Before the viscera can be removed an incision must be made in abdomen and normally the sternum ("brisket") is cut longitudinally from the throat area to the end point of the abdomen.

In normal dressing of carcasses of sheep, goats, cattle, calves, pigs and deer the carcass is suspended by the rear legs and the pelt, or in the case of pigs, the hair, is hygenically removed prior to viscera removal. Normally a knife is used initially to clear the sphincter muscle from the carcass. A knife is also used by a skilled operator to cut the abdomen wall from the point between the rear legs to the brisket. As the rumen (paunch) presses against the abdomen wall while this incision is taking place it is possible that even a skilled operator can inadvertently cut the thin wall of the rumen resulting in contamination of edible meat by the contents of the stomach. In some species of animal, e.g. sheep, goats and deer, the rumen together with the liver and spleen are removed after the abdominal wall is cut but before the brisket is cut. For other species of animal, however, e.g. cattle and pigs, the brisket is cut prior to removal of the viscera. 9 o .1 3 The brisket is either cut with a circular or reciprocating saw or in the case of some small animal species with pneumatically powered shears. Irrespective of the method of cutting the brisket there is always a risk of the heart being cut or punctured thereby reducing its value.

The cutting or sawing of the brisket allows the balance of the viscera (i.e. heart, lungs, trachea) in those animals where the paunch has already been removed to be removed by a skilled operator using a knife.

The present invention relates to a method and means which allows the brisket and abdomen of an animal carcass to be cut without causing damage to the internal organs of the carcass.

Accordingly the invention in one broad aspect provides a method for opening an animal carcass including the steps of suspending the carcass by its forelegs, positioning a support frame with a circular saw such that the circular saw is located between said forelegs, positioning said support frame such that the circular saw comes into cutting contact with the carcass and moving said support frame relative to the carcass such that the circular saw substantially follows the contour of the brisket such as to form a cut therein.

Preferably, upon completion of the cut in the brisket the support frame is moved downwardly such that a cut is formed in the abdominal wall of the carcass, said circular saw including a shield which covers a part of the peripheral cutting edge of the blade and being positioned such as to lie within the carcass such that during said lowering of the circular saw the abdominal wall and viscera are separated by the shield. referably the support frame is moved in a combined downward NEW ZEALAND ""aird—crtt-frwjard movement relative to the carcass such as to follow the ^SJUN1987 , contour (of the brisket.

PATEMT OFRCE preferably the circular saw is sterilized at the lowermost 214 J13 point in its travel prior to being raised preparatory to being used to open a further carcass. apparatus for opening an animal carcass comprising a circular saw blade mounted by support means, said saw blade being adapted for coupling to prime mover means to impart rotation to the blade, moving means coupled with said support means whereby said support means can be moved between an upper and lower position relative to a substantially vertically suspended animal carcass, said moving means, in use, moving said support means from said upper position so that the saw blade is in cutting contact with the ♦ '', brisket of the carcass and substantially follows the contour of the brisket such as to form a cut therein.

Preferably the support means is movable such as to move the saw blade over the abdominal wall of the carcass and form a cut therein, there being further included a shield which covers . a part of the peripheral cutting edge of the blade during at least movement of the cutting blade along the abdominal wall said shield being located within the carcass such that the abdominal wall and viscera are separated by the shield.

In the following more detailed description reference will be made to the accompanying drawings in which Figure 1 is a side elevational view of the circular saw according to a first form of the invention.

Figures 2 and 3 are cross-sectional plan views on secti'dii ^ ^ line X-X of Figure 1 showing two different embodiments of conjunction with a carcass of an animal suspended for dressing, In a second broad aspect of the invention there is provided shield saw, Figure A is a side elevational view of the circular < 4 204013 Figures 5-10 are similar to Figure 4 but showing the circular saw and carcass in the different stages of the carcass being opened for viscera removal, Figure 11 is a side elevational view of a second form of the invention, Figure 12 is a perspective view of the arrangement in Figure 11 in conjunction with support frame and operating mechanism, and Figures 13 to 16 are side elevational views showing the arrangement of Figure 12 when in different stages of opening the carcass for viscera removal.

The invention as hereinafter described provides a simple machine method of cutting the brisket and cutting the abdominal wall of an animal carcass using a circular saw for both operations. The carcass C, which has had its skin or pelt removed, is suspended by its forelegs F, either from the front hocks or the front hooves. It is preferred, but not essential, that the rear legs R be located and pulled downwardly to apply a small longitudinal tension to the carcass. This can be achieved, for example, by inserting a gambrel inside the archilles tendon of the two rear legs. A carcass suspended preparatory to being opened up by the saw is shown in Figure 4.

Referring to Figures 1, 2 and 3 the circular saw is illustrated and this consists of a circular saw blade 10 mounted for rotation within a suitable frame 11. A shield 12 in the form of a substantially elongate pin 14 is mounted by frame 11 and this pin 14 has a recess or slot 15 in which a sector of the r-, / n 1 "7 l. U 4 U I peripheral cutting edge of the blade is located. Pin 14 is preferably formed with a curved outer surface 16 and two different forms of cross-section of pin 14 are shown in Figures 2 and 3. Blade 10 is adapted for coupling to a prime mover so that it can be rotated in the direction of the arrow shown in Figure 1.

Frame 11 is suspended from a suitable support means (not shown) which allows the frame 11 to be moved from an upper position as shown in Figure 4 to at least a lowermost position as shown in Figure 9 but preferably a position as shown in Figure 10. In the uppermost position the frame 11 can be pivoted so that it can take up the position shown in Figure 5.

Referring firstly to Figure 4 the circular saw is shown in its uppermost position with the blade stationary. To commence the cutting operation the saw is pivoted to the position shown in Figure 5 whereupon the blade is located between the forelegs F of the carcass C.

The saw is then switched on and is lowered to a point which is predetermined relative to the brisket B itself or the neck of the carcass. Sawing of the carcass commences by the saw being swung through the arc indicated in Figure 6. The design of the pin 14 is such that its length does not extend beyond the cut left by the saw while it is rotated through this arc and reaches the position shown in Figure 7. As the heart is positioned well back from the brisket bone when the carcass is suspended by its front legs accidental cutting of the heart is thereby prevented. 2o*oi3 ;Once the position shown in Figure te- is reached the saw is then lowered so as to follow a downward movement and thereby cut the final part of the brisket B and the abdominal wall A. The pin" 14 whichfte located within the carcass^shields the saw from cutting the paunch. Once the circular saw has travelled downwardly to a certain point as illustrated in Figure 9 the force of the pin 14 on the abdominal wall increases until the pin breaks out of the body cavity and automatically clears the carcass. The opening of the carcass is thereby complete and the circular saw can be returned to its uppermost position, however, it is preferred that at the end of the downstroke the saw enters a sterilisation cabinet (shown generally at 18 in Figure 10) before returning to its uppermost position (Figure 4) preparatory to processing the next animal. ;The complete viscera V can now either be removed with the carcass shown in the position in Figure 10 or the carcass can be reinverted onto its back legs and evicerated conventionally. ;Referring to Figure 11 a second form of the cutting apparatus is shown. The apparatus includes the same basic elements as the first form with the shield, however, being of an alternative embodiment and incorporates an enlarged curved leading portion 16a which is connected by a tapered body portion 14a forming the equivalent of the aforementioned pin 14 of the previously described form. ;The apparatus further includes a pair of skids 17 located beneath the saw blade 10. The skids 17 have a curved carcass ;/ ;NEW ZEALAND ;- 7 - ;-6 JUL 1987 ;PATENT OWE j ;■? 0 P < 7 ;. .. J lj , J ;1*7• engagement portion and are lintroducod so as to travel down the exterior of the abdomen during the opening up phase.

Referring to Figure 12 there is shown a form of support frame and operating mechanism. A main frame upright 20 is mounted on a suitable base 21 and located between a pair of spaced apart flanges 22 is a main hydrualic cylinder 23.

Attached to the body of cylinder 23 is an outwardly projecting support 24 to which is pivotally attached an arm 25. An hydraulic motor 26 is mounted by arm 25 and drives the saw blade 10. Located within the end of the support is a control mechanism for control of movement of the arm 25.

Itf. arm 35» and has pivotally attached at 28 a lever 29. A pneumatic cylinder 30 has its body pivotally attached to mounting 27 and its piston rod 31 pivotally coupled at 32 to lever 29. The other end of the lever 29 carries the skids 17.

Main frame upright 20 has a second pair of projecting flanges 33 between which is pivotally mounted a secondary frame 34. This frame 34 has a locating arm 35 and a support arrangement 36 for the sterilizer casing 18. A rod 3€fe,carried by frame 34 is journalled for sliding movement in a bearing block 37 on )arm In use the pneumatic cylinder 30 is controlled so as to extend and retract the skids 17. A suitable control mechanism is provided for moving the skids from the retracted position (as shown) in Figure 12 to its extended or working position. The ■"> ,r)«n 1 7 i' n u i J main hydraulic cylinder 23 is likewise controlled to move the support 24 upwardly and downwardly in accordance with the method according to the present invention.

Referring to Figures 13 to 16 the various stages of opening the carcass when using the form of the invention shown in Figure 12 are shown. Figure 13 shows the skids 17 retracted (i.e. at rest) and the arm 25 pivoted upwardly, in the direction of the arrow, to be situated preparatory to the support 24 being lowered. The disposition of the saw blade 10 and carcass C is such that as the arm 25 moves upwardly the blade 10 does not make contact with the brisket. Figure 14 shows the initial downward movement, with skids 17 still retracted, of the support 24 to position the blade 10 in the brisket cutting position.

Figure 15 shows the arm 25 being pivoted downwardly through 90° so that blade 10 cuts the brisket whereupon skids 17 are moved to the working position where they contact and exert pressure on the belly. Figure 16 shows the downward movement of support 24 to enable the belly to be cut until the pin 14 breaks through the abdomen wall. The support 24 continues down until the skids 17, blade 10, and shield are located in the sterilizer casing 18.

The aforedescribed method and means of opening'an animal .carcass is simple, hygenic and provides a mechanical means of brisket cutting and opening up. The method and means for carrying out the method ensures that internal organs of the carcass are not damaged during the opening up procedure. =? 0 40:3

Claims (15)

WHAT WE CLAIM IS :

1. A method for opening an animal carcass including the steps of suspending the carcass by its forelegs, positioning a support frame with a circular saw such that the circular saw is located between said forelegs, positioning said support frame such that the circular saw comes into cutting contact with the carcass and moving said support frame relative to the carcass such that the circular saw substantially follows the contour of the brisket such as to form a cut therein.

2. The method according to claim 1 wherein upon completion of the cut in the brisket the support frame is moved downwardly such that a cut is formed in the abdominal wall of the carcass, said circular saw including a shield which covers a part of the peripheral cutting edge of the blade and being positioned such as to lie within the carcass such that during said lowering of the circular saw the abdominal wall and viscera are separated by the shield .

3. The method according to claim 1 or 2 wherein the support frame is moved in a combined downward and outward movement relative to the carcass such as to follow the contour of the brisket.

4. The method according to claim 2 or 3 wherein during lowering of the support frame a skid or skids is brought to bear on the outer surface of the carcass and is moved so as to precede the advance of the saw.

5. The method according to any one of claims 1 to 4 wherein the rear legs of the carcass are located by locating means.

6. The method according to claim 5 wherein a downward longitudinal tension is applied to the carcass.

7. The method according to any one of preceding claims 2 to 6 - 10 - wherein the saw is sterilized at the lowjer'moBt—point—&-£ its travel NEW ZEALAND after having cleared the carcass. -5JUN1987 PATENT OFf 2"4J13

8. The method of opening an animal carcass as claimed in claim 1 or 2 as herein described.

9. Apparatus for opening an animal carcass comprising a circular saw blade mounted by support means, said saw blade being adapted for coupling to prime mover means to impart rotation to the blade, moving means coupled with said support means whereby said support means can be moved between an upper and lower position relative to a substantially vertically suspended animal carcass, said moving means, in use, moving said support means from said upper position so that the saw blade is in cutting contact with the brisket of the carcass and substantially follows the contour of the brisket such as to form a cut therein. q

10. Apparatus according to claim & wherein the support means is movable such as to move the saw blade over the abdominal wall of the carcass and form a cut therein, there being further included a shield which covers a part of the peripheral cutting edge of the blade during at least movement of the cutting blade along the abdominal wall said shield being located within the carcass such that the abdominal wall and viscera are separated by the shield.

11. The apparatus according to claim 10 wherein one or more skids are locatable by locating and moving means beneath the saw blade to precede said blade during its movement between said upper and lower positions.

12. The apparatus according to claim 11 wherein a skid is positioned below and to either side of the saw blade. 2«»4J13

13. The apparatus according to claim 11 or 12 wherein the or each skid has a curved carcass engagement surface which in operation of the apparatus engages with the carcass. 1A.

The apparatus according to any one of preceding claims 2 to 13 wherein the shield has a leading end which has a curved surface to ensure smooth contact between said leading end and' the interior of said carcass.

15. Apparatus for opening an animal carcass for viscera removal substantially as herein described with reference to the accompanying drawings. THE MEAT INDUSTRY RESEARCH INSTITUTE OF NEW ZEALAND (INCORPORATED) By their Attorney DON HOPKINS Registered Patent Attorney -12-