METHOD AND APPARATUS FOR CUTTING/BREAKING BLOCKS OF FROZEN MEAT

The present invention relates to a method and apparatus for cutting/breaking blocks of frozen meat or other material and is particularly concerned with cutting/breaking and separating a stack of blocks of frozen meat for use in pet food and which are delivered on a pallet.

In the processing of pet food, rectangular blocks of frozen meat have generally hitherto been delivered to processing plants in stacks on a wooden pallet and the blocks have to be manually unloaded therefrom and fed into the processing machine. It sometimes occurs as a result of inappropriate freezing that the blocks bond together and are difficult to separate. It has been proposed previously to provide sheets of plastic between the block although sometimes such become embedded- especially when provided between the pallet and the lowermost layer of blocks as the meat can be deformed between the planks of the pallet and create a bond therewith requiring destruction of the pallet.

It is an object of the present invention to provide an apparatus which enables stacks of blocks of frozen meat or other material to be separated and broken up and discharged from the apparatus for further processing.

According to the present invention apparatus for cutting/breaking a stack of blocks of frozen meat or other material comprises reciprocable cutting and displacing means, means for supporting said meat or other material and means for exposing upper portions thereof in stepwise manner to said reciprocable cutting and displacing means which is then operable cut and/or break

such stack into smaller pieces and displace such to discharge for further processing. The reciprocable cutting and displacing means is such as to provide the combined function of cutting and subsequently displacing the cut pieces in one and the same movement and comprises a cutting edge or blade having a displacing portion extending upwardly therefrom such as to cause the cut and/or broken off pieces of meat to be displaced to discharge. Preferably the cutting and displacing means is so shaped and/or dimensioned or is so shaped and/or dimensioned and disposed (e.g. by being tilted) such that after each cutting stroke no meat remains thereon. Preferably the cutting and displacing means is also so shaped and/or dimensioned that no meat falls over the top thereof so as not to be displaced to discharge.

The cutting and displacing means is preferably in the form of a generally horizontal cutting edge or blade from which there extends firstly, rearwardly and upwardly relatively to the normal cutting direction, a displacing portion which then extends more towards the vertical and then, preferably, forwardly and upwardly to additionally prevent meat falling rearwardly over the top.

Preferably in the region behind the cutting edge, the displacing means is so shaped so as to prevent meat accumulating there, for example, by providing a flat upwardly inclined surface. Also, the displacing portion of the cutting and displacing means is so shaped and dimensioned so as to prevent breaking off or broken off pieces of frozen meat jamming and impeding the motion of said cutting means. Also one or more upwardly and preferably vertically extending ribs or dividers may be provided along the length of the cutting and displacing means to reduce the likelihood of meat pieces remaining on the blade. Preferably such dividers are in the form

of wedge shaped webs.

The means for supporting the meat preferably comprises a housing having an open top and an open bottom and is preferably rectangular to be like the sides of a box and has a displaceable meat supporting bottom displaceable in step-wise manner such that the increments of indexing displacement, which are preferably adjustable in throw, expose the required amount of meat to the cutting blade for satisfactory operation. To provide clearance on the inoperative, return stroke of the reciprocating cutting and displacing means, the displaceable bottom is controlled to drop slightly prior to the next elevating movement and prior to the return movement of the cutting means. A platen displaceable by a suitable scissors linkage with suitable control means synchronised with the movement of the cutting and displacing means is preferably provided as the displaceable bottom.

Preferably two such housings forming the means for supporting the blocks of meat are provided with each being displaceably mounted on tracks extending on opposite sides of the means for elevating the blocks of meat with each being movable from its associated side forming a meat block loading position wherein a fixed bottom closes the lower part of the housing to a position over the displaceable bottom for elevation of the meat blocks. Whilst one housing or "bin" is being unloaded, the other housing or "bin" can be loaded with further meat blocks for subsequent displacement to overlie the displaceable bottom part for subsequent cutting and discharge. The housings are thus reciprocated for alternate loading and discharging.

Preferably the cutting and displacing means is

mounted o ; _a g§l.lers and/or split slider blocks running in tracks and—said means are parallel displaceable by at least three hydraulic pistons. The movement of the various parts of the apparatus will be synchronised and controlled by suitable control means.

Also according to the present invention a method for cutting/breaking blocks of frozen meat or other comprises loading a stack of such blocks into a housing means for supporting the meat, causing a cutting and displacing means to execute reciprocal movement in a horizontal or inclined plane, effecting relative indexing movement between the meat and the reciprocating cutting and displacing means prior to each cutting stroke, cutting said meat during each cutting stroke and at the same time displacing cut meat to discharge. Preferably said stack of blocks of frozen meat is turned on its side prior to loading in the housing such that the edges of the blocks face upwardly i.e. the generally rectangular blocks extend upwardly.

Also according to the present invention there is provided a cutting and displacing means per se as previously described.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: -

Fig. 1 is a plan view of an apparatus for cutting/breaking blocks of frozen meat and forms a preferred embodiment of the invention;

Fig. 2 is an elevation of the apparatus of Fig. 1 viewed from the direction of arrow B;

Fig. 3 is a section on the line A-A of Fig. 2;

Fig. 4 is a section through the cutting and

displacing means of Figures 1 and 2 although drawn in disposition reversed through 180°;

Fig. 5 is a plan of the cutting and displacing means of Fig. 4;

Fig. 6 is a rear elevation of the cutting and displacing means of Fig. 4 and Fig. 6a is a transverse cross section of the displacing means having a top plate extension; and

Fig. 7 is a schematic illustration of an inclined meat housing and cutting and displacing means disposed to minimise meat retention on the cutting and displacing means.

The apparatus as illustrated comprises a cutting and displacing means or "blade" 2 to which is mounted to be reciprocably displaceable along tracks 3 by means of rollers (not shown) and/or split slider blocks (not shown) mountable on stub shafts 4 (Fig.5).

Three hydraulic rams 5 are connected to the rear side of blade 2 with the cylinders thereof being mounted on a supporting frame 6.

Beneath blade 2 there is disposed means for supporting blocks of frozen meat in the form of a housing 7 of generally rectangular shape formed an open topped and open bottomed box with the reciprocable blade 2 traversing the top thereof. Beneath the housing 7 there is provided a displaceable bottom or platen 8 which is displaceable by means of a scissor lift 9 controlled to move in step-wise or indexing upward movements synchronised with the movements of blade 2. The control (not shown) of the scissor lift 9 is preferably such as to lower the platen 8 slightly following a cutting movement of blade 2 so as to provide clearance for blade 2 on its return inoperative movement. Subsequently the scissor lift will raise the blocks of meat supported on

platen 8 by a requisite amount prior to the next cutting stroke of blade 2. The control means is preferably adjustable so as to enable the indexing amount to be adjusted as desired depending upon conditions and the nature of the material being cut. The platen 8 with housing 7 located thereover is displaceable within housing 7 to raise meat blocks supported thereon.

The blade 2 after effecting the cutting operation pushes broken off pieces of meat into a discharge feed conveyer 10 which has a hopper portion 11 leading to a screw conveyer 12 which carriers the broken off pieces of meat for further processing. A bell shaped enlargement (not shown) at the discharge end of the screw 12 is provided to prevent jamming and furthermore a breaking pin extends from the shaft of the screw in such region to further prevent jamming. A meat retaining rearwall 14 is provided and two lateral meat retaining side walls 15 are provided in the upper region of housing 7.

Support tracks 16 extend across the machine generally parallel to blade 2 and underneath the housing 7 and have two displaceable meat supporting housings or "bins" 17, 18 supported thereon in rolling engagement by roller bearings 19 and the bins 17 and 18 are generally rectangular and in the form of an open top and open bottom box and form a further part of the means for supporting the meat in addition to housing 7. A stationary meat supporting table 20, 21 is provided on opposite sides of the blade 2 and forms the bottom of respective bins 17, 18 when located in their loading position thereover. Suitable control means and displacing means, limit switches etc are provided for displacing bin 17 and 18 alternately from their loading positions L2, LI respectively so that when one bin is directly under the blade 2 for discharge therefrom, the

other bin in its loading position whereafter upon discharge of the first mentioned bin, such is displaced to its loading position and the other bin displaced to be under the blade 2 for discharge.

Suitable stop barriers 22 are provided in loading positions LI, L2 to limit the movement of a forklift truck which will deliver stacks of frozen meat on a pallet (not shown) to be loaded into the respective bins without the pallet. Preferably the stack of frozen meat which will comprise generally rectangular blocks in horizontal disposition will be turned through 90° so that the blocks point upwardly and the ends thereof are acted upon by blade 2. The area beneath rams 5 is closed off by suitable protective screens 23.

It will be appreciated from the foregoing that the shape of the reciprocable cutting and displacing means or cut "blade" "2" is of importance. Figs. 4, 5 and 6 illustrate a preferred embodiment although various modifications may be made. The blade illustrated comprises top and bottom plates 24, 25 and end plates 26 interconnected at the top rear by a box section girder 27 and having at the front meat displacing means 28. At the lower end of means 28 and replaceably connected to bottom plate 25 is a cutting blade or edge 29. The three rams 5 are connected and controlled so as to ensure parallel displacement of "blade" 2. The blade 2 is mounted by means of rollers on stub shafts 4 or split slider blocks.

Rearwardly of cutting edge of 29 the meat displacing means comprises an upwardly extending curved portion 30 which is welded to a generally planar upwardly extending portion 31 which has at its upper end a portion 32 extending upwardly and forwardly and away from a

vertical passing through the transition region thereof with said portion 32 being provided to prevent meat from . falling to the rear of the blade 2.

In operation, as the cutting edge 29 moves into the frozen meat, portions thereof are cut and as the blade moves forward, the cut portions abut the portions 30, 31 of the displacing means and tend to "cure" upwards. It is of importance that such portions ^l 30,31 be shaped and dimensioned and inclined so that the meat does not jam in such position and causing stalling of the machine or requiring additional energy. This jam prevention is achieved by not having a vertically extending displacing portion adjacent edge 29 and preferably by having and inclined and/or curved displacing surface such as by the radius of the first portion 30 with the planar portion 31 may be inclined to the vertical at an angle of 25° to the vertical or, for example, in the range of 15-30° to the vertical. Additionally, one or preferably three wedge shaped vertically extending webs 33 may be provided across the width of the displacing portion 28 to facilitate the prevention of jamming. The "blade" 2 may be some 2400 mm in length 2.5 metre width at the base and a height of approx. 440 mm.

It is also of importance to ensure that after executing a cutting/breaking operative stroke, that meat is not retained on blade 2 and such can be achieved by appropriate shaping of the portions of the displacing means. It has been found that the provision of a "fill- in" plate 34 possibly as a cord on portion 30 across the width of the blade or between the webs 33 will prevent the accumulation of meat in such portion. Additionally or alternatively, the blade may be arranged so as to be displaceable in a plane inclined to the horizontal with

the support for the meat being similarly inclined such as schematically illustrated in Figure 7 such that meat will fall from the blade to at the end of its operative traverse.

The parallel movement of blade 2 is ensured by pinions meshing with racks (not shown) located on stub shafts at opposite ends of the blade 2 as indicated in the hatched central circle in Fig. 4. The broken circles in Fig. 4 indicate the stub-shaft mountings whilst the continuous circle is the mounting for the hydraulic cylinder.

In operation with the bins 17 and 18 being in the position illustrated in Fig. 1 and with bin 17 being located on platen 8 and having blocks of frozen meat extending upwardly therefrom, blade 2 moves from a retracted position more adjacent frame 6 than shown commences its movement towards discharge 14 once the scissor-lift 9 has been raised by a requisite amount by the control means to lift the meat on platen 8. The cutting edge 29 of the blade 2 cuts into the blocks of meat such that the partially severed portions then abut the portions 30 or 34 and 31 and are then broken off into smaller pieces and with a continued movement of the blade across the top of housing 7, the cut and broken off pieces of meat are displaced into discharge hopper 11. During such operation the platen or table 8 is preferably mechanically locked in position rather then reliance upon the hydraulics.

Prior to the return movement of the blade 2 away from the conveyor 12, the lock 2 is released and the hydraulic control lowers the platen 8 slightly so as to provide clearance for the blade 2 which then is retracted over the top of the meat and to one side thereof whereupon the control means of the scissor linkage 9

raises the platen 8 by a requisite mount so as to expose a further requisite amount of meat into the cutting region of blade 2 whereupon the blade executes its operative movement with the operation being repeated and the platen being indexed upwardly until all the meat has being discharged from platen 8 whereupon platen 8 is then lowered to beneath the bottom of bin 17 which is then displaced to the right in Fig. 1 and to its loading position L2 whilst at the same time the newly loaded bin 18 is displaced to above platen 8 and such is then discharged in the same manner as bin 17.

During the change of bin 17, a fork-lift truck or like may be moving into loading position LI and carrying a pallet with blocks of frozen meat in horizontal disposition stacked vertically thereon whereat said stack is displaced through 90° and loaded in to position without the pallet into bin 18,

In the loading positions, LI and L2 the bottom of the bins is closed with slight clearance by means of a deadplate which extends across to the region of the lifting platen 8 so that, upon displacement of the bins, the meat blocks slide on said deadplates and on to platen 8. During discharge, the screw conveyors operate to carry meat away to the next processing stage. By way of example and for information, the platen may raise the meat approximately 180 mm for each cutting operation.

The speed of the displacing means for the blade (i.e. preferably three hydraulic rams) , is preferably adjustable or is preferably operable at two different speeds - depending upon conditions. For heavy loads a greater pressure but slower speed is required.

in the apparatus of Figs. 1 to 7, the blade 2 is described as being mounted in its lower region by means of rollers (not shown) and/or split slider blocks (not shown) mounted on stub shafts (Fig. 5) which roll or slide along guides or tracks 3 located adjacent the bottom of blade 3. In a preferred modification, rollers and/or split slider blocks or the like travelling means are located in. an upper region of the blade 3 and run on tracks or other suitable guide means. This modification avoids or minimizes the likelihood of the rollers and/or blocks and especially the guide means from being clogged or contaminated by meat from the housing therefor.

Fig. 8 is a transverse section through an alternatively shaped cutting and displacing means or "blade" 35 but without the cutting edge which is not shown but is as edge 29 in Fig. 4. In Fig. 8, the "blade" 35 comprises top and bottom plates 36, 37 with a cutting edge 29 being securable to the front lip of plate 37. End plates 45 and side, retaining plates 46 (only one of each shown) are provided and a front, meat displacing means 38 is provided. Displacing means 38 comprises a first upwardly and rearwardly extending planar portion 39, a second displacing portion 40 which extends more towards the vertical than portion 39 and running through the upper end of portion 39, and a third meat retaining portion 41 extending forwardly of the vertical running through the upper end of portion 40 with respect to the normal direction of cutting and displacement of blade 35 and to prevent or inhibit meat falling onto plate 36.

A heavy cylindrical tube extends behind the displacing means 38 and at its opposite ends 42 serves as the mounting for pinions (not shown) which mesh with racks to ensure parallel displacement, Rearwardly of

mounting 42, there are apertures 47 for mounting rollers and/or split slider blocks or the like travelling means rolling or sliding in lateral guide means (not shown) parallely mounted in the upper region of blade 35 whilst rearwardly and downwardly thereof, apertures 48 are provided for further rollers or slider blocks running in lower guide means. Two tubes 43 of square cross-section are provided to provide rigidity to the structure and to form part of the supporting frame 44. Beneath tubes 43, two circular mountings 49 as different positions of connection for the hydraulic piston and cylinder rams.

Various modifications may be made without departing from the scope of the present invention.