GB1589713A - Cutting apparatus - Google Patents

Description

(54) IMPROVEMENTS IN AND RELATING TO CUTTING APPARATUS (71) We, CODAT MANAGEMENT LIMITED, a British Company, of Witchampton, Wimborne. Dorset BH21 5AG, 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: This invention is concerned with improvements in and relating to apparatus for use in the cutting of portions of cheese or other soft non-granular substances such as fat or meat loaf.

Cheese is produced in parallelepiped blocks, generally of the order of 40 Ibs weight. For distribution and retail sale these blocks require to be cut into portions, each portion being individually and separately packed. Automatic packaging machines are known such as have a matrix of compartments each for a single portion of cheese, which matrix can be formed from plastic film wrapping material. When the compartments have been loaded each with a portion of cheese, a second sheet of wrapping material can be laid over the loaded matrix and can be united with the first sheet at the edges of the compartments to complete as many portion-filled containers of wrapping material as there are compartments in the matrix. The filled containers can be separated from one another in any suitable fashion.

According to the present invention there is provided apparatus for cutting a block of a soft non-granular substance into a plurality of portions, the apparatus comprising a platen to receive a block to be cut; drive means for advancing the platen from a starting position in steps to a fully advanced position; first cutter means for cutting into the block along the direction of advance of the block on the platen; and second cutter means for cutting the block in a direction transverse to the direction of advance of the block on the platen whereby operation of the first and second cutter means produces a layer of portions cut from the block, the drive means being adjustable to set the size of steps in which the platen advances, and thus the thickness of the layer of portions produced, to any desired value and to set the minimum size of step to any required minimum value so that, in use, regardless of the size of the block, the advance of the platen from its starting position to its fully advanced position is accomplished by a plurality of steps of said desired value and at least one step equal to or greater than said required minimum value.

The invention will be better understood from the following description of a preferred embodiment thereof, given by way of example only, reference being had to the accompanying drawings, in which Figure 1 is a diagrammatic plan and elevation of apparatus for receiving cheese blocks, cutting portions and removing the cut portions; Figure 2 is a diagrammatic sectional view on the line II-II of Figure 1 on an enlarged scale; Figure 3 is a schematic plan view of the transfer mechanism of the apparatus of Figure 1 for moving cut portions from the block to the compartments of a matrix of a wrapping machine; Figure 4 is a schematic section on the line IV-IV of Figure 3; Figure 5 is a cross-section and an underneath view of á transfer head; Figure 6 is a detail elevation of a row of transfer heads;; Figure 7 is a plan view of an alternative transfer mechanism; Figure 8 is a side elevation of the transfer mechanism of Figure 7; Figure 9 is a diagrammatic illustration of a control system for the cheese platen, with the driving mechanism for cylinder X omitted in the interest of clarity, and Figure 10 is a diagrammatic illustration of the driving mechanism of the cylinder X of Figure 9.

Referring to Figure 1, cheese blocks 1 are fed by a gravity conveyor 2 to an entry gate section 3 and a loading platform 4 comprising rollers. The blocks roll forward under gravity down the conveyor 2 and by alternate action of a clamping cylinder 5 and a gate check cylinder 6 are released one at a time to the platform 4.

A cylinder 7 is then extended to raise the roller loading platform 4 into a horizontal position when a block is positioned thereon and, after a stop gate 8 on the platform 4 has withdrawn, a cylinder 9 thrusts the cheese block 1 on to a cutting platen or platform 10 on which it is precisely positioned by the actions of cylinder 9 and a cylinder 11 forcing the cheese against back stops, not shown.

The platen 10 is then raised vertically by a cylinder 12 under the control of a control system to be described hereinafter so that the upper part of the block is forced through a cutting head 13 which has fixed crossed cutting wires 1 3a to cut the block vertically.

The top surface of the block is raised only to a predetermined level and vacuum transfer heads 14 are each driven down by individual cylinders 1 5 to engage the top of the cheese block to clamp the cheese. A cylinder 16 then operates to move a cutter 17 with a single horizontal wire 17a to cut that art of the cheese block already penetrated by cutting head 13 to provide a layer of individual portions. The cut portions are removed by withdrawing the transfer heads 14 upwards, after which cylinder 16 retracts the cutter 17 for the next operation.Cylinder 12 then raises the cheese block to cause the upper part to be penetrated further by the cutting wires 13a whereafter the transfer heads 14 again engage the upper face of the block and cylinder 16 again operates cutter 17 and the next layer is ready for removal, these actions being repeated until all but the last layer has been removed. The last layer of portions is removed by the transfer heads after the platen 10 has been raised to the level of the cutter 17, no action of the cutter 17 being necessary for the last layer. After all the layers have been removed, cylinder 12 returns the platen 10 to its lowest position for the next block to be loaded.

The transfer mechanism shown in Figures 3-6 has twelve transfer heads 14, but the number of transfer heads may be varied to suit the packaging machine being served.

Referring to Figure 3, the transfer heads are shown, tor the purposes of illustration, in two alternative configurations, it being understood that in fact the mechanism only includes one set of twelve heads. The heads 14 are carried on carrier bars 18a, 18b, 18c, themselves movable on support bars 19.

Each head is provided with a plurality of, e.g. twelve, suction apertures or orifices, in that face which will engage the cheese, arranged as a pattern to be spread over the upper surface of a cheese portion. Automatic controls ensure that vacuum is applied to the heads as soon as the heads reach the cheese when each head is driven down under the influence of its individual cylinder 1 5. All the transfer head cylinders operate simultaneously and after the layer of portions has been cut by cutter 17 the cylinders rctract the heads upwards, each transfer head taking with it a portion of cheese. The transfer heads are in this case arranged in three rows of four heads to a row. The four heads in a row are mounted on a common carrier bar and each carrier bar is supported on bearings 18B on the support bars 19.

Support bars 19 are fixed and form a track extending from the cutting machine to a position over a wrapping machine indicated at W. The carrier bars are movable along the support bars 19 by a cylinder anchored to a main frame to couple the leading carrier bar indicated at 18a in the direction of travel toward the wrapping machine. The following carrier bars i8b and 18c will be drawn along by the leading bar as will appear. The transfer head 14 at one end of each row, that shown at the top in each row in Figure 3, engages a cam track C and as each such transfer head travels toward the packaging machine it is moved by the cam track away from its neighbour in that row.Being suitably coupled to its neighbour by a lost motion connection it will entrain its neighbour after itself being displaced by the cam track and the neighbour will in due time through a similar lost motion connection entrain the next head in the row, and so on.

Referring to Figure 6 the lost motion connections are shown in a row of transfer heads 14 on carrier bar 18a along which they are displaceable in accord with the cam track C. The transfer heads are shown in process of being spaced apart. This same lost motion connection is suitable for coupling heads in adjacent rows, or as shown adjacent carrier bars together. Each transfer head has two upstanding apertured plates 23. A link 24 is slidably received in the apertures of two plates, one on each of two neighbouring transfer heads. The link has end stops 25 which will not pass through the apertures. In the result when two transfer heads are close together as when over a block of cheese the spacing between plates coupled by a link is less than the spacing of the link heads. When one transfer head is displaced along the carrier bar, during initial movement the link is inoperative. But when the plates are spaced sufficiently they will be engaged by the heads of the link and the second transfer head is then entrained by the first. Thus a row of transfer heads on a carrier bar will be moved along the carrier bar by the action of the cam track and the links from a first closely spaced relationship over the cheese block to a second spaced apart relationship by the time the carrier bar is over the wrapping machine. The last transfer head in a row is anchored as at L (Figure 6) in any suitable fashion to the carrier bar. Likewise displacement of carrier bar 1 8a will entrain the other carrier bars by similar lost motion connections during displacement from a closely spaced relationship over the block to a position over the wrapping machine. Links for entraining transfer heads in a row and carrier bars are diagrammatically shown in Figure 3.

In Figures 7 and 8 an alternative transfer mechanism arrangement is shown where a cylinder 20 is coupled to a pull bar 27 itself coupled by springs 28 to the leading carrier bar 1 8a which is coupled in turn by springs 29 to the following carrier bars. Stops will halt each carrier bar as it arrives over its respective row of compartments in the matrix. A second cylinder 30 with a pull bar 31 will engage each head at an adjacent end of each row when the carrier bars are over the matrix and draw that head away from its neighbour. Again by lost motion links each head will entrain the next.

Reverse action of cylinder 20 returns the spaced carrier bars to a closer spacing above the block for the next cycle which returns the heads in each row to their closer relationship by action of the cam track.

When the portions are correctly located at the matrix, indicated at M in Figure 4, with a film of wrapping material in position, the sub-atmospheric pressure is changed to super-atmospheric pressure, this ensuring release of the portions by the transfer heads and clearing the air passages of any crumbs.

The transfer heads are readily accessible to an operator and the surfaces of the heads which come into contact with the cheese can be wiped over without removal from the machine. To provide for frequent washing and sterilizing the heads can be removed individually. Heads can be interchangeable so that with a duplicate set of heads one set can be in use whilst the other is being cleaned.

The transfer heads themselves are preferably as shown in Figure 5.

Each transfer head has tubular coupling member 30 for connection selectively to a pressure source and a source of subatmospheric pressure. A manifold 32 having apertures 33 in one face is carried by coupling 30 which may be one of two cylindrical spigots which serve as guides for vertical movement of the transfer head by its cylinder 15 in a carrier plate 28 (Figure 6). On that apertured face is carried a resilient pad 34, comprising a plurality of resilient cups 35, one for each aperture, which will bear upon a portion.For individual cheese portions of 1 to 16 oz, it is found that apertures of 0.4 mm diameter with cups of 0. cc volume and 170 mm2 aperture at the larger open end, with sub-atmospheric pressure of 600 mm mercury will create a satisfactory vacuum pull of 400 mm in the cups in not more than 0.5 seconds, giving a force of approximately 0.4 kg per cup. If one or more of the cups do not seal on the portion due, for example, to unevenness. the leak rate is approximately 3.5 litres/minute per unsealed cup.

In an alternative arrangement of transfer head (not shown), the face to engage the portion may be a resilient pad perforated with apertures of the same order as mentioned above for the plate.

The whole apparatus can be made as a mobile unit to allow for ready access to the packaging machine.

To enable portions of any desired thickness to be taken from a cheese block a feed mechanism is provided such that the thickness can be preselected and is infinitely variable up to for example a maximum of 50 mm. Because blocks of cheese vary in size, the use of a preselected portion thickness could lead to the production of a final remnant waste layer too thin for packaging.

Remnant waste is eliminated by the feed mechanism described below by ensuring that final layers of portions of a preselected minimum thickness are cut, this minimum also being infinitely variable up to for example 20 mm.

To produce the optimum portions from the random remnant of the block after as many portions of the desired thickness as possible have been cut, the feed mechanism ensures that the last portion layer is always in excess of the selected minimum thickness and never above twice this thickness. For example, if 25 mm is the desired thickness and 10 mm the minimum, from a block of 180 mm the equipment would cut six layers of 25 mm and two of 15 mm: from a 175 mm block the last two layers would be 12.5 mm, and from 165 mm there would be six layers of 25 mm and one final layer of 15 mm. From a block of 158 mm, five layers of 25 mm would be cut and two of 16.5 mm.

Referring to Figures 9 and 10, the feed mechanism comprises: a main cylinder E which raises the platen or platform 10; free surface (no piston) reservoirs R1, R2; a free piston reservoir R3 having a working volume equal to the volume of fluid necessary to displace the piston of cylinder E from its lowest position to its highest position; metering cylinders X, Y; and two cylinders X' mechanically coupled to the piston of cylinder X and operable to drive this piston between two extreme positions.In addition, the system includes air valves V1, V2; hydraulic fluid valves L1, L2, L3, L4, L5; sensors Sxl, Sx2 which signal respective positions of the piston of cylinder X; sensors Syl, Sy2 which signal respective positions of the piston of cylinder Y; sensor Se which signals a lower position of platen 10; sensor Sr which sign als when the pistons of cylinders X and Y are at the same level; sensor Sd which signals when the top of a block of material to be cut is at a datum level corresponding to the level of the cutting wire 17a; and sensor Sz which signals when the free piston in reservoir R3 has reached the bottom of the cylinder.The valves and sensors are connected to a programmed controller whereby in use opcning and closing of the valves is controlled automatically in rcsponse to signals received from the sensors as hereinafter described.

The reservoir R3 and cylinders X. Y, and E are completely fillcd and rcservoirs Rl and R2 are partly filled, with an incompressible non-toxic hydraulic fluid.

In describing the operation: x = desired portion thickness, and determines the amount by which E advances between each cut; Vx = volume of fluid required to raise the piston E by x; y = minimum portion thickness; Vy = volume of fluid to raise cylinder E byy; V E = the volume of fluid necessary to dis- place the piston of cylinder E from its lowest position to its highest position, and equals the working volume of reservoir R3.

The volumes of cylinders X and Y are equal and not less than the maximum desired value of Vx. Vr is the volume of fluid required to raise E by a distance equal to the thickness r of any random remnant of cheese less than thickness x + y.

Before use, sensors Sxl and Syl are set to determine respectively the desired portion thickness x and the minimum portion thickness y. Also, the position of the platen 10 on the piston rod of cylinder E is adjusted so that when cylinder E is fully extended, the platen is 2 to 4 mm below the level of sensor Sd.

In use, programme control produces the following operating sequences, all valves being closed unless otherwise stated: 1. With a cheese block mounted on platen 10, valves Ll, L3 and L4 are opened and valve Vl is positioned so as to apply air pressure to reservoir Rl and vent reservoir R2 freely to atmosphere. This causes hydraulic fluid from reservoir Rl to flow into reservoir R3, forcing the piston in reservoir R3 down to displace fluid into cylinders Y and E. This causes the pistons of these cylinders to rise, displacing fluid above the pistons into reservoir R2. When the piston of cylinder Y has risen far enough to trigger sensor Syl, valve L3 is closed to trap volume Vy below the piston of cylinder Y.

Valve L4 is closed as soon as the top of the block of cheese reaches sensor Sd.

2. With valve L1 o en, valve V2 is then set to drive cylinders X ' positive, which in turn drives cylinder X positive, drawing fluid from reservoir R3 into cylinder X. This continues until sensor Sxl is triggered, indicating the cylinder X contains volume Vx below its piston, whereupon valves Ll and L5 are closed.

3. With valve L4 open, valve V2 is then set to drive cylinders X', and with them cylinder X negative until sensor Sx2 is triggeared, thereby dumping volume Vx of fluid into cylinder E to raise the block of cheese a distance x. This causes crossing cuts to be made in the block by wires 13a. Cutter 17 then operates to cut off a layer of portions, which portions are then removed by the transfer mechanism as described above.

4. The operations of paragraphs 2 and 3 above are repeated until no more fluid remains below the piston of reservoir R3, and an amount of fluid less than Vx is contained below the piston of cylinder X. Sensor Sz is then triggered but because the amount of fluid below the piston of cylinder X is less than Vx, sensor Sxl will not be triggered.

5. Valve L3 is opened and valve V2 is set to drive cylinder X negative, forcing fluid from cylinder X into cylinder Y and thus raising the piston of cylinder Y above the position indicated by Syl. If at the end of the operation of paragraph 4, cylinder X contained more fluid than cylinder Y, the point will be reached as cylinder X is driven negative that both cylinders X and Y contain an equal amount of fluid. At this point, sensor Sr is triggered and the operating sequence continues as in paragraphs 6 and 7. If in the alternative, at the end of the operation of paragraph 4, cylinder X contained less fluid than cylinder Y, cylinder X will be driven fully negative and sensor Sr will not be triggered. In this case, when the cylinder X is fully negative, all fluid from cylinder X will have been transferred to cylinder Y, and sensor Sx2 will be triggered.

The operating sequence then continues as in paragraphs 8 and 9.

6. When Sr is triggered, cylinders X and Y contain equal volumes A Vr below their pistons, the total contained, Vr, being the exact volume required to raise the platen 10 the distance r from its position at the end of the operation of paragraph 4 to its fully raised position. Cylinder X is then driven negative with valve L4 open until sensor Sx2 is triggered. This dumps volume E Vr from cylinder X into cylinder E and raises the platen 10 by a distance E r. The cutter 17 then operates and a layer of portions of thickness r r is removed.

7. Cylinder X is then driven positive with valve L3 open, thereby lowering the piston of cylinder Y until sensor Sy2 is triggered and transferring volume 1 Vr from cylinder Y to cylinder X. Cylinder X is then driven negative with valves L4 and L5 open until sensor Sx2 is triggered, thereby dumping volume 2 Vr into cylinder E and raising platen 10 a further distance 2 r to its fully raised position. The final layer of portions each of thickness 2 r is then removed. It will be noted that since 2 Vr is greater than Vy and less than Vx, the thickness of each of the last two layers, 2 r, is greater than y and less than x.

8. If sensor Sx2 is triggered without sensor Sr being triggered it is an indication that the block of cheese remaining on the platen at the end of paragraph 4 has a total thickness less than twice the minimum thickness y. This remaining block must be removed as a single layer. To this end, upon sensor Sx2 being triggered, valve V2 is set to drive cylinder X positive with valve L3 open until all fluid from cylinder Y is transferred to cylinder X and sensor Sy2 is triggered.

9. Cylinder X is then driven negative with valves L4 and L5 open to raise the platen 10 to its highest position so that the final remnant layer of portions is removed.

After each cutting sequence the equipment is automatically re-set under programme control. During re-setting, valve V1 is positioned to apply air pressure to reservoir R2 and vent reservoir R1 to atmosphere, and with valves L1 and L4 open and cylinder X driven positive fluid is forced from reservoir R2 into cylinder E to drive the piston of cylinder E downward and displace fluid from below the piston into reservoir R3. This raises the piston in cylinder R3 and causes fluid above the piston to return to reservoir R1. When the piston of cylinder E reaches its fully retracted position, sensor Se is triggered and with valves L1 and L2 open cylinder X is driven negative.Under the action of the pressure in reservoir R2, the piston in reservoir R3 is returned to its highest position, thereby compensating for any leakage of fluid past the various seals which may have occurred during the cutting sequence.

After re-setting, the equipment is ready to receive another block to be cut.

It will be noticed that the desired portion thickness and the minimum portion thickness are determined by the positions of the sensors Sx1 and Syl respectively. By mounting these sensors on suitable adjustment means, the desired portion thickness and minimum portion thickness can be made continuously adjustable over a wide range.

The adjustment of portion thickness may be carried out quickly and easily and thus the equipment can be used to produce a range of portion thicknesses without difficulty.

WHAT WE CLAIM IS: 1. Apparatus for cutting a block of a soft non-granular substance into a plurality of portions, the apparatus comprising a platen to receive a block to be cut; drive means for advancing the platen from a starting position in steps to a fully advanced position; first cutter means for cutting into the block along the direction of advance of the block on the platen; and second cutter means for cutting the block in a direction transverse to the direction of advance of the block on the platen whereby operation of the first and second cutter means produces a layer of portions cut from the block, the drive means being adjustable to set the size of steps in which the platen advances, and thus the thickness of the layer of portions produced, to any desired value and to set the minimum size of step to any required minimum value so that, in use, regardless of the size of the block, the advance of the platen from its starting position to its fully advanced position is accomplished by a plurality of steps of said desired value and at least one step equal to or greater than said required minimum value.

2. Apparatus according to claim 1 wherein the starting position of the platen is intermediate the fully advanced position and a fully retracted position of the platen and the drive means is operable to advance the platen from its fully retracted position to the starting position prior to advancing the platen from the starting position in steps to the fully advanced position and to return the platen to the fully retracted position after it has reached the fully advanced position.

3. Apparatus according to claim 2 including a sensor which is triggered when the leading surface of a block located on the advancing platen reaches a predetermined datum position, the starting position of the platen being the position of the platen when the sensor is triggered.

4. Apparatus according to any preceding claim wherein the drive means is such that, after the platen has advanced by a sufficient number of steps of the desired size for the thickness of the remainder of the block on the platen to be less than the sum of the desired value and the required minimum value, the drive means determines whether the remainder of the block on the platen can be cut into two layers of equal thickness greater than the required minimum value, and in the event that the remainder can be so cut, advances the platen for the remainder to be cut accordingly.

5. Apparatus according to any preceding claim wherein the drive means comprises a closed circuit hydraulic system including: an hydraulic ram for advancing the platen; a main hydraulic fluid reservoir; a reserve hydraulic fluid reservoir to hold sufficient fluid to advance the platen by said required minimum value, and a variable volume metering reservoir for metering into the hydraulic.ram successive volumes of

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. driven negative with valves L4 and L5 open until sensor Sx2 is triggered, thereby dumping volume 2 Vr into cylinder E and raising platen 10 a further distance 2 r to its fully raised position. The final layer of portions each of thickness 2 r is then removed. It will be noted that since 2 Vr is greater than Vy and less than Vx, the thickness of each of the last two layers, 2 r, is greater than y and less than x. 8. If sensor Sx2 is triggered without sensor Sr being triggered it is an indication that the block of cheese remaining on the platen at the end of paragraph 4 has a total thickness less than twice the minimum thickness y. This remaining block must be removed as a single layer. To this end, upon sensor Sx2 being triggered, valve V2 is set to drive cylinder X positive with valve L3 open until all fluid from cylinder Y is transferred to cylinder X and sensor Sy2 is triggered. 9. Cylinder X is then driven negative with valves L4 and L5 open to raise the platen 10 to its highest position so that the final remnant layer of portions is removed. After each cutting sequence the equipment is automatically re-set under programme control. During re-setting, valve V1 is positioned to apply air pressure to reservoir R2 and vent reservoir R1 to atmosphere, and with valves L1 and L4 open and cylinder X driven positive fluid is forced from reservoir R2 into cylinder E to drive the piston of cylinder E downward and displace fluid from below the piston into reservoir R3. This raises the piston in cylinder R3 and causes fluid above the piston to return to reservoir R1. When the piston of cylinder E reaches its fully retracted position, sensor Se is triggered and with valves L1 and L2 open cylinder X is driven negative.Under the action of the pressure in reservoir R2, the piston in reservoir R3 is returned to its highest position, thereby compensating for any leakage of fluid past the various seals which may have occurred during the cutting sequence. After re-setting, the equipment is ready to receive another block to be cut. It will be noticed that the desired portion thickness and the minimum portion thickness are determined by the positions of the sensors Sx1 and Syl respectively. By mounting these sensors on suitable adjustment means, the desired portion thickness and minimum portion thickness can be made continuously adjustable over a wide range. The adjustment of portion thickness may be carried out quickly and easily and thus the equipment can be used to produce a range of portion thicknesses without difficulty. WHAT WE CLAIM IS:

1. Apparatus for cutting a block of a soft non-granular substance into a plurality of portions, the apparatus comprising a platen to receive a block to be cut; drive means for advancing the platen from a starting position in steps to a fully advanced position; first cutter means for cutting into the block along the direction of advance of the block on the platen; and second cutter means for cutting the block in a direction transverse to the direction of advance of the block on the platen whereby operation of the first and second cutter means produces a layer of portions cut from the block, the drive means being adjustable to set the size of steps in which the platen advances, and thus the thickness of the layer of portions produced, to any desired value and to set the minimum size of step to any required minimum value so that, in use, regardless of the size of the block, the advance of the platen from its starting position to its fully advanced position is accomplished by a plurality of steps of said desired value and at least one step equal to or greater than said required minimum value.

2. Apparatus according to claim 1 wherein the starting position of the platen is intermediate the fully advanced position and a fully retracted position of the platen and the drive means is operable to advance the platen from its fully retracted position to the starting position prior to advancing the platen from the starting position in steps to the fully advanced position and to return the platen to the fully retracted position after it has reached the fully advanced position.

3. Apparatus according to claim 2 including a sensor which is triggered when the leading surface of a block located on the advancing platen reaches a predetermined datum position, the starting position of the platen being the position of the platen when the sensor is triggered.

4. Apparatus according to any preceding claim wherein the drive means is such that, after the platen has advanced by a sufficient number of steps of the desired size for the thickness of the remainder of the block on the platen to be less than the sum of the desired value and the required minimum value, the drive means determines whether the remainder of the block on the platen can be cut into two layers of equal thickness greater than the required minimum value, and in the event that the remainder can be so cut, advances the platen for the remainder to be cut accordingly.

5. Apparatus according to any preceding claim wherein the drive means comprises a closed circuit hydraulic system including: an hydraulic ram for advancing the platen; a main hydraulic fluid reservoir; a reserve hydraulic fluid reservoir to hold sufficient fluid to advance the platen by said required minimum value, and a variable volume metering reservoir for metering into the hydraulic.ram successive volumes of

fluid from the main reservoir each sufficient to advance the platen by a step of the desired value.

6. Apparatus according to claim 5 wherein when the platen is fully retracted and the reserve reservoir and metering reservoir are empty, the usable volume of fluid in the main reservoir is sufficient to advance the platen to its fully extended position.

7. Apparatus for cutting a block of soft non-granular substance, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.