GB2055673A - Meat moulding machine - Google Patents

Abstract

A meat moulding machine includes a meat supply cylinder (not shown) for supplying meat to a moulding head 3. Control means are provided for controlling the supply of meat to, and the operation of, the moulding head 3. The moulding head 3 comprising a thimble 10 in which a barrel 11 is rotatably mounted. The barrel 11 is provided with seven moulding apertures 12 (only one shown) each containing a reciprocable piston 13. Each moulding aperture 12 is alignable with a respective inlet 14 and outlet 15 formed in the thimble 10. The control means is such that meat is supplied to each inlet 14 whenever the corresponding aperture 12 is aligned therewith, the meat forcing the pistons 13 down thereby ejecting moulded material from the spaces below the piston 13 via the outlets 15. The barrel 11 is then rotated to bring the filled ports of the apertures 12 into alignment with the outlets 15. The meat may be scampi meat, wet fish, mince or small pieces of meat or soya. <IMAGE>

Description

SPECIFICATION Meat moulding machine This invention relates to a meat moulding machine, particularly for moulding sea food meats such as prawn or scampi meat.

Scampi moulding machines are used for forming reasonable sized pieces of scampi from scampi which would otherwise be too small for human consumption. Known scampi moulding machines suffer from a number of disadvantages. In particular, it is difficult to ensure a regular supply of meat to the moulding head of the machine so as to ensure continuous operation of the head. Difficulties also arise in shaping the moulded scampi portions and in separating adjacent portions.

Moreover, known machines are difficult to disassemble and re-assemble for the regular cleaning and sterilisation which is necessary for such machine.

The present invention provides a meat moulding machine comprising a moulding head, a meat supply cylinder for supplying meat to the moulding head, and control means for controlling the supply of meat to the moulding head and for controlling the operation of the moulding head, the moulding head comprising a thimble and a barrel rotatably mounted within the thimble, the barrel being provided with at least one moulding aperture containing a reciprocable piston, the or each moulding aperture being alignable with a respective inlet formed in the thimble and with a respective outlet formed in the thimble, wherein the control means is such that meat is supplied to the or each inlet whenever the corresponding aperture is aligned therewith.

Advantageously, the control means comprises a control valve and a pneumatic control circuit. Preferably, the control valve has three ports, a first of which is connectible to a meat supply hopper, a second of which is connected to the meat supply cylinder, and the third of which is connected to the moulding head. Conveniently, the control valve is actuated by means of a pneumatic control cylinder which forms part of the pneumatic control circuit.

The barrel may be rotated within the thimble, via a pawl-and-ratchet mechanism and a gear train, by extending or retracting a pneumatic head cylinder which forms part of the pneumatic control circuit. The head cylinder may be actuated by a pneumatic control valve. Preferably, said pneumatic control valve is a lever-operated control valve. Advantageously, the control means is such that the barrel is rotated in 90 turns. Alternate 90 turns may be initiated by first and second arms of a rotatable timer turret actuating said pneumatic control valve. Advantageously, the first and second arms actuate the pneumatic control valve to extend the head cylinder and a second pneumatic control valve is actuated when the head cylinder is fully extended to retract the head cylinder.Preferably, the second pneumatic control valve is mounted on the head cylinder, and is pressure-operated.

Conveniently, the timer turret has three pairs of first and second arms.

The meat supply cylinder may be actuated by means of a pneumatic operating cylinder which forms part of the pneumatic control circuit. Advantageously, pressurisation of the operating cylinder is controlled by means of a third pneumatic control valve. Preferably, the third pneumatic control valve is actuated by the head cylinder so that the operating cylinder causes the meat supply cylinder to supply meat to the moulding head when the head cylinder has rotated the barrel into a position in which the or each aperture is aligned with its inlet and outlet. Advantageously, means are provided for removing the air supply to the operating cylinder whenever air is supplied to the head cylinder.Preferably, said air removing means is constituted by a fourth pneumatic control valve which is operated by the first pneumatic control valve when actuated by a second arm of the timer turret. The fourth pneumatic control valve may be pressure-operated.

The meat moulding machine may further comprise a conveyor for moving trays under the moulding head. Advantageously, the conveyor carries pushers for pushing the trays one-by-one under the moulding head. Preferably, the pneumatic control circuit includes a pneumatic start valve and a pneumatic stop valve for starting and stopping respectively the moulding operation. Conveniently, the start and stop valves are lever-operated valves which are actuated by the pushers. The control means may be such that six moulding operations occur between the actuation of the start valve and actuation of the stop valve.

Preferably, a fifth pneumatic control valve is provided for preventing moulding being initiated unless a tray is under the moulding head. Conveniently, the fifth pneumatic control valve is a lever-operated valve which is actuated by the passage of a tray thereover.

Advantageously, means are provided for controlling the period during which the or each aperture of the barrel is aligned with its inlet and outlet. Preferably, said means is constituted by a pneumatic variable timer which forms part of the pneumatic control circuit. Means may also be provided for preventing the head cylinder being pressurised before air is removed from the operating cylinder. Preferably, said means includes a pneumatic fixed timer which forms part of the pneumatic control circuit. The fixed timer ensures that the air supply to the head cylinder is delayed until the air supply to the operating cylinder has been removed.

Preferably, the pneumatic control valve circuit includes a pneumatic flow control valve for controlling the pressurisation of the operating cylinder.

The invention also provides a moulding head for a meat moulding machine, the moulding head comprising a generally tubular thimble and a generally cylindrical barrel rotatable within the thimble, the barrel being provided with at least one diametrical moulding aperture containing a reciprocable piston, the or each aperture being alignable with a respective inlet and a respective outlet formed in the thimble, wherein the barrel is provided with two blades which contact the inner wall of the thimble adjacent the two ends of the or each mouldng aperture.

Preferably, the barrel is provided with seven parallel moulding apertures, each containing a reciprocable piston. In this case, the thimble is provided with an inlet manifold for directing meat particles towards the moulding apertures. Advantageously, each of the pistons is formed with an elongate longitudinal slot, a rod passing through the slots in the pistons being provided for controlling the movement of the pistons in the moulding apertures.

Advantageously, each blade is mounted in a slot formed in the barrel. Preferably, each blade is made of non-toxic hard plastics material and is biassed outwardly towards said inner wall of the thimble. The biassing of the blades may be accomplished by means of resilient non-toxic rubber strips each of which is positioned between the base of the respective slot and the adjacent end of the respective blade. Conveniently, the blades are held in position by means of non-toxic rubber rings fitted to the ends of the barrel.

The invention also provides a moulding head for a meat moulding machine, the moulding head comprising a generally tubular thimble and a generally cylindrical barrel rotatable within the thimble, the barrel being provided with at least one diametrical moulding aperture containing a reciprocable piston, the or each aperture being alignable with a respective inlet and a respective outlet formed in the thimble, wherein the barrel is rotatably mounted in the thimble by means of low friction pads mounted in, and extending slightly beyond, the outer cylindrical surface of the barrel.

In this case, the barrel and thimble can both be made of stainless steel. Preferably, four pads are positioned at each end of the barrel, each pad being mounted in a hole in the cylindrical surface of the barrel.

An embodiment of the invention will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of the meat moulding machine; Figure 2 is a perspective view of a partially filled tray passing under the moulding head of the machine; Figure 3 is a perspective view of the drive unit for the moulding head; Figure 4 is a perspective view of the meat feed cylinder and the control valve of the machine; Figure 5 is a schematic side elevation showing the timing means for the moulding machine.

Figure 6 is part-sectional elevation of the moulding head; Figure 7 is a part-sectional elevation (taken on the line A-A of Fig. 6) of the barrel of the moulding head; Figure 8 is a cross-section taken on the line B-B of Fig. 7; and Figures 9 to 20 are diagrams showing the sequence of operations of the control valve circuit of the machine.

Referring to the drawings, Fig. 1 shows the general arrangement of the meat moulding machine, which has a meat supply cylinder 1, a control valve 2, a moulding head 3, a tray conveyor 4 and a tray magazine 5. The meat supply cylinder 1 has a pneumatically-controlled operating cylinder 1 a. The meat supply cylinder 1 is provided with a piston (not shown) which is attached to the piston of the operating cylinder 1 a. Compressed air from a source (not shown) can be applied via control valve means (see Figs. 9 to 20) to the operating cylinder 1 a When the operating cylinder 1 a is actuated, its piston is extended. As the piston of the meat supply cylinder 1 is joined to the piston of the operating cylinder 1 a, it too is extended so as to force the meat in the cylinder 1 towards the moulding head 3.

The control valve 2 has three ports 2a, 2b and 2c, the port 2a being connected to a meat supply hopper (not shown), the port 2b leading to the meat supply cylinder 1 and the port 2c leading to the moulding head 3. The valve 2 is controlled, via a control cylinder 8, by a valve 6 which forms part of the control valve means. The control valve means synchronises the actuation of the operating cylinder 1 a with the opening and closing of the ports 2a, 2b and 2c. Thus, when the operating cylinder 1 a is actuated, the valve 2 is positioned to allow positive pressure to act on the piston of the operating cylinder 1 a via the port 2b. At the same time, the meat contained in the cylinder 1 is forced out and into the moulding head 3.

The tray conveyor 4 is driven, via a chain and sprockets, by a variable speed gearbox 37 powered by an electric motor (not shown).

Trays 36 are fed from the tray magazine 5 along the tray conveyor 4 and through the machine in the direction of the arrow (see Fig.

5). Pushers 4a are provided on the conveyor 4 to engage the trays 36 and push them through the machine. The pushers 4a are also used to start and stop the control valve means by operating the valve 6 (the stop valve) and a start valve 7.

The moulding head 3 (see Fig. 6) is constituted by an inlet manifold 9, a generally tubular thimble 10, and a barrel 11 rotatable within the thimble. The barrel 11 is provided with seven moulding apertures 1 2 (only some of which can be seen in Fig. 7). Each aperture 1 2 is provided with a free floating piston 1 3 (only one of which can be seen in Figs. 6 and 7), the two ends of each aperture being aligned with respective inlets 14 (Fig. 6) leading to the manifold 9, and with respective outlets 15, as the barrel 11 is rotated within the thimble 10. The barrel 11 and the thimble 10 are made from stainless steel, the barrel rotating within the thimble with a clearance of 0.203 millimetres.The annular clearance between the barrel 11 and the thimble 10 is maintained by means of four low-friction bearing pads 31 (see Fig. 8) which are set into 9.53 millimetre holes in the barrel and bear on the inner surface of the thimble. The clearance between the pads 31 and the inner surface of the thimble 11 is 0.025 millimetres.

Two doctor blades 1 6 (see Fig. 6) which are made of non-toxic hard plastics material, are slotted into the barrel 11. The doctor blades 1 6 are urged outwards, by the action of resilient non-toxic rubber strips 17, to ensure tight contact with the inner surface of the thimble 10. Two rings 18, which are made of non-toxic rubber, are fitted on to the ends of the barrel 11 to retain the doctor blades 1 6 in position. The pistons 1 3 are made of nontoxic plastics material. The free ends of each piston 1 3 are provided with U-shaped sealing rings 1 9 seated in grooves 19 a. These rings 1 9 are made of a non-toxic rubber, neoprene or other non-toxic synthetic material.

The barrel 11 is driven via pneumatic head cylinder 20, a lever 21, a pawl-and-ratchet mechanism 22 and 23, and a gear train 24, 25, 26 and 27 (see Fig. 3). The pneumatic head cylinder 20 is controlled by a valve 28 which forms part of the control valve means.

The valve 28 is in turn controlled by the arms 40 and 41 of a timer turret 30 (see Fig. 5).

The timer turret 30 has three arms 40 and three arms 41, the arms 40 and 41 being arranged in three equispaced pairs.

The moulding head 3 described above operates in the following fashion. The sequence of operations is initiated upon an empty tray 36 reaching the moulding head 3, by a pusher 4a actuating the start valve 7. Immediately before one of the arms 40 of the timer turret 30 actuates the valve 28, the barrel 11 is positioned with its moulding apertures 1 2 at right-angles to the inlets and outlets 14 and 1 5. When the arm 40 actuates the valve 28, an air control sequence which is described below with reference to Figs. 11 to 14 is set in motion, and, provided a magazine valve 42 has been actuated by a tray 36 leaving the magazine 5, the head cylinder 20 is actuated.

This transmits a rotary movement to the barrel 11 via the lever 21, the pawl-and-ratchet mechanism 22 and 23, and the gear train 24, 25, 26 and 27. The extension of the head cylinder 20 is such that a 90 rotation is imparted to the barrel 11. The barrel 11 is then positioned with its moulding apertures 12 aligned with the inlets and outlets 14 and 15. The lever 21 then actuates a valve 29 (see Fig. 3), which forms part of the control valve means, which allows air pressure to the operating cylinder 1 a.This causes the piston of the operating cylinder 1 a to extend, and hence the piston of the meat cylinder 1 is also extended to force meat in the cylinder 4 out through the ports 2 b and 2e of the control valve 2, through the manifold 9 and into the moulding apertures 1 2 via the inlets 14. The meat forces the pistons 1 3 down and ejects moulded meat fr9m the spaces below the pistons via the outlets 1 5.

When the head cylinder 20 has completed its extension stroke, the control valve means causes the head cylinder to retract in a manner which is described below with reference to Fig. 14. Then, the arm 41 of the next pair of arms actuates the valve 28 to set in motion an air control sequence which is described below with reference to Figs. 1 5 to 1 7. When the valve 28 is actuated, the head cylinder 20 is extended, this extension transmitting a rotary movement to the barrel 11 via the lever 21, the pawl-and-ratchet mechanism 22 and 23, and the gear train 24, 25, 26 and 27.

The extension stroke of the head cylinder 20 causes a 90 rotation of the barrel 11. The actuation of the valve 28 by the arm 41 also cuts off (in a manner to be described below with reference to Fig. 15) the supply of air to the operating cylinder 1 a so that there is no pressure on the meat whenever the barrel 11 is rotating.

This cycle of extension and retraction of the head cylinder 20 is repeated five more times during the passage of the tray 36 under the moulding head 3. The stop valve 6 is then actuated by a pusher 4a. As the moulding sequence occurs six times during the passage of each tray 36, and there are seven moulding apertures 12, fortytwo moulded portions are deposited on each tray. The provision of three pairs of arms 40 and 41 on the timer turret 30 means that the latter is rotated through two complete revolutions whilst each tray 36 passes beneath the moulding head 3.

When the stop valve 6 is operated, an air control sequence, described below with reference to Figs. 18 and 19, is set in motion, and the air supply to the valve 28 is switched off.

Thus, the moulding head 3 does not function between the operation of the stop valve 6 and the initiation of the next series of cycles by the operation of the start valve 7. This period of moulding head inactivity corresponds to the space between the trays 36 on the conveyor 4. The air control sequence initiated by the actuation of the stop valve 6 also permits air to reach the control cylinder 8. The resulting extension of the control cylinder 8 positions the control valve 2 so that the port 2a is connected to the port 2h Once this has happened, air is permitted to retract the operating cylinder 1 a. This retracts the piston of the meat supply cylinder 1 so that meat from the hopper is drawn into that cylinder via the ports 2a and 2b.Immediately the operating cylinder 1 a is fully retracted, air is transferred to retract the control cylinder 8 which repositions the control valve 2 with the port 2b connected to the port 2a. When this action is completed, the air path to the operating cylinder 1 a is repositioned so that, when the moulding head cycle is again initiated by actuation of the start valve 7, air will be permitted to pressurise the operating cylinder at the appropriate time in the cycle.

The operation of the control valve means will now be described with reference to Figs.

9 to 20, which show the valves 6, 7, 28 and 29 and 42, the cylinders 1 a, 8 and 20 and the timer turret 30 described above. These figures also show the following valves: 50-a flip-flop valve 51-a flip-flop valve 52-a NOT unit (that is to say a valve that has no output if both its inputs are pressurised) 53-a NOT unit 521 a flip-flop valve 55-a flip-flop valve 56-a flip-flop valve 57-a flip-flop valve 58-a variable timer (that is to say a valve having a variable delay between the arrival of an air input and the depar ture of an air output) 60--an OR unit (that is to say a valve which has an output if either of its two inputs are pressurised) 61-a pilot-operated valve 62-a pilot-operated valve 63-a signalmaster valve 64---an an OR unit 65-a fixed timer (that is to say a valve having a fixed delay between the ar rival of an air input and the departure of an air output) 66-an OR unit 67-an OR unit 68-an OR unit 69-a pilot-operated valve 70a NOT unit 71-a pilot-operated valve 72-a NOT unit 73-a flow control valve 721 3 signalmaster valve 75-a reset valve Valves 6, 7, 28 and 42 are lever-operated control valves, and valve 29 is a plungeroperated control valve. Figs. 9 to 20 shows the air lines connecting the various valve and cylinders, and each figure shows those lines with "air-on" as thickened.

Fig. 9 shows the arrangement at the completion of one cycle (that is to say when a tray 36 has passed right through the apparatus and has received its fortytwo moulded portions of meat) and prior to initiation of the meat cycle. Thus, the stop valve 6 has been operated and the operating control cyclinder 8 and the operating cylinder 1 a have operated and are in a recharged operating condition.

When the start valve 7 is operated (see Fig.

10), a pulse of air is passed to the valve 50 to turn this valve on so as to permit air to pass to the valve 28 via the valve 51. This passage of air to the valve 28 is possible only if the valve 51 is supplied with air by the magazine valve 42 which, in turn, only passes air if opened by the passage of a tray 36 along the conveyor 4 from the magazine 5 to the moulding head 3. The start valve 7 is operated by a pusher 4a, this being timed to occur when the time turret 30 is in the position shown in Fig. 10.

When the valve 28 is actuated by an arm 40 of the timer turret 30 (see Fig. 11), it passes a pulse of air to one input of the valve 52. This pulse of air also passes to the valves 53, 54 and 56. The pulse of air reaching the valve 53 switches this valve off, thus removing the pilot supply to the valve 54. The pulse of the air reaching the valve 54 from the valve 28 passes through to the valve 55 which switches the valve 55 over and passes air to the other input of the valve 52. As the valve 52 is a NOT unit, it remains closed. At the same time, the change-over of the valve 55 removes the air supply. from the valve 53 (shown in dotted lines in Fig. 11) and so permits this valve to be switched off as described above. The pulse of air reaching the valve 56 from the valve 28 switches the valve 56 over so that air passes to the variable timer 58 via the valve 57.

When the arm 40 of the timer turret 30 releases the valve 28 (see Fig. 12) the valve 28 closes and removes the air supply from said one input of the valve 52. As the valve 52 is now supplied with air at said other input only, it passes a pulse of air to the valve 54 and to the valve 29. The pulse of air reaching the valve 54 changes over this valve.

When the variable timer 58 times out (that is to say when an air output is emitted), an air pulse passes to one input of the valve 60 and then on to the valve 61. This changes over the valve 61 to pass air to the head cylinder 20 so as to force its piston outwards (see Fig.

13). Just before the piston rod of the head cylinder 20 completes its extension stroke, it strikes the plunger of the valve 29 to open this valve to pass air to the valve 62. The opening of the valve 29 also passes a pulse of air to the valve 57 whch changes over and passes air to the other side of the valve 62.

Thus, the valve 62 does not, at this stage, change over as it receives air from both sides.

The change-over of the valve 57 also removes the air from the input of the variable timer 58 (shown as a dotted line in Fig. 13). The changeover of valve 57 also passes air to the other input of the valve 60 so that the pulse of air from the output of this valve to the valve 61 is cut off.

At the end of its extension stroke, the piston rod of the head cylinder 20 actuates the signalmaster 63 (see Fig. 14) which passes air to the valve 64 which, in turn, passes air to one pilot input of the valve 56.

This changes over the valve 56 which changes over the valve 57 and cuts off the air supply to said other side of the valve 62. The valve 62 can now change over to allow air to pressurise the operating cylinder 1 a. The air pulse from the signalmaster 63 also passes to the input of the fixed timer 65 which, after a fixed delay which serves no purpose at this stage of the cycle, passes a pulse of air to the valve 66 which, in turn passes a pulse of air to the valve 61. This changes over the valve 61 so as to pressurise the head cylinder 20 in the direction of retraction.

The arm 41 of the next pair of arms on the timer turret 30 now operates the valve 28 (see Fig. 15). Whilst the valve 28 is open, it passes a pulse of air to one input of the valve 52. At this stage, the other input of the valve 52 receives air from the valve 55, so the valve 52 has no output. The valve 28 also passes a pulse of air to one input of the valve 53. At this initial stage, the other input of the valve 53 has no air supply. The valve 28 also passe a pulse of air through the valve 54 to the valve 67. This valve 67 opens and passes air to the valve 55 which changes over to pass air to the other input of the valve 53 and to remove air from the other input of the valve 52 (shown as a dotted line in Fig. 15). The valve 52 remains closed as does the valve 53 which now has two inputs.The valve 28 also passes a pulse of air to the valve 56, thus changing this valve over and passing air through the valve 57 to the valve 62. This changes over the valve 62 and cuts off the air supply to the operating cylinder 1 a. The air from the valve 57 also passes to the valve 60 which opens to pass air to the valve 61. This air opens the valve 61 thus pressurising the head cylinder 20 for movement in the direction of extension.

When the head cylinder 20 is fully extended, the signalmaster 63 is again operated to pass a pulse of air to the valve 64 (see Fig.

16) which opens to pass air to the valve 56.

However, the valve 56 is still receiving air from the valve 28 (which is still open), so it does not change over. The pulse of air from the signalmater 63 also passes to the fixed timer 65 whose output (to the valve 66) is delayed by a fixed time which is sufficient to allow the valve 28 to close before the valve 66 opens.

When the fixed timer 65 times out (see Fig.

17) and sends a pluse of air to the valve 66, the valve 28 has closed as the arm 41 of the timer turret 30 has over-run the lever of the valve 28. Thus, the valve 28 no longer passes air to the valve 53 so that, as this valve now has only one input, it passes a pulse of air to the valve 54 to change over that valve. The valve 53 also sends a pulse of air to the valve 57 to chanve over that valve. As the valve 28 is closed, the supply of air to the valve 56 is cut off so that the valve 56 is also changed over. On timing out, the fixed timer 65 also sends a pulse of air to the valve 66 which passes air to the valve 61 which changes over to pressurise the head cylinder 20 in the direction of rectraction.

The sequence of operations shown in Figs.

10 to 1 7 occurs five more times before the stop valve 6 is actuated by a pusher 4a (see Fig. 17). Thus, between the start valve 7 being actuated and the stop valve 6 being actuated, six cycles each as shown in Figs. 10 to 1 7 occur.

When the six cycles have been completed, a pusher 4a actuates the stop valve 6 (see Fig. 1 8) which opens to pass a pulse of air to the valve 67 which opens to pass air to the valve 50 switching this valve off. The valve 67 also passes air to the valve 69 which changes this valve over to pressurise the control cylinder 8 to move in the direction of extension. When changed over, the valve 69 also passes air to one input of the valve 70 which switches off as its other input is also pressurised. Thus, the air supply from the valve 70 to the valve 71 is cut off. The change over of the valve 69 also cuts off the supply of air to the valve 72 which permits air to pass from the valve 72 to the valve 71.

Consequently, the valve 71 is changed over to allow air to pass through the flow control valve 73 and on to the operating cylinder 1 a.

The operating cylinder 1 a (and hence the meat cylinder 1) are thus pressurised in the direction of retraction, and so draw in meat for the next complete cycle of operations. As the tray 36 has now left the machine, the valve 42 closes to switch off air to the valve 51. Thus, air does not pass through the valve 51 to the valve 28 so that when a tray 36 is not passing through the machine, it is not possible to actuate the head cylinder 20. At the same time a pulse of air passes from the stop valve 6 to the valve 57 to change this valve over.

When the operating cylinder 1 a has fully retracted (see Fig. 1 9) the signalmaster 74 is actuated to pass a pulse of air to the valve 69 which changes over and pressurises the con trol cylinder 8 in the direction of retraction.

The air from the valve 69 also passes to the valve 72 to switch this valve off (its other input already having an air supply). The change over of the valve 69 also removes the air supply from the valve 70 which then opens (having only one input) to pass air to the valve 71. This air changes over the valve 71 to permit air to reach the valve 62.

The circuit is now in the condition shown in Fig. 9, and so is ready for the next cycle of operation. The complete cycle is, therefore from Fig. 9 to Fig. 19 with the sequence of Figs. 10 to 1 7 occuring six times.

Fig. 20 shows how the reset sequence operates, the reset sequence being used to set the circuit to the condition shown in Fig 9.

When the plunger of the reset valve 75 is depressed, pulses of air are passed to the valves 64, 66, 67 and 68. The valve 66 then opens to pass a pulse of air to the valve 61 which, in turn, pressurises the head cylinder 20 in the direction of retraction. Similarly, the control cylinder 8 is retracted following actuation of the valves 67, 55, 50 and 69.

The small clearance between the barrel 11 and the thimble 10 ensures that the meat portions to be moulded are cleanly sheared by the co-operation of the relatively moving edges of the apertures 1 2 and the inlets and outlets 14 and 1 5. This shearing action is improved by the provision of the doctor blades 1 6 which are positioned in the barrel 11 to follow directly the aperture 1 2 as the barrel rotates within the thimble 10.This shearing action is further improved by the pressure set up between the doctor blades 1 6 and the inner wall of the thimble 10 under the action of the resilient strips 1 7. This shearing action is particularly important where the meat being moulded is scampi meat, as it results in ciean cutting of the fibrous scampi meat and hence in accurately moulded scampi portions. Known scampi moulding machines have operated with a similar clearance between the barrel and thimble (utilising roller bearings for barrel support rather than the low friction pads 31 of the machine of the invention). However, such machines do not utilise doctor blades which results in poor separation of the pieces of scampi and hence inaccurate moulded portions.

The size and shape of the moulded portions are controlled by the size of the pistons 1 3, the length of the slots 38 in the pistons, the flow control valve 73 which controls the speed of movement of the operating cylinder 1 a (and hence that of the meat supply cylinder, and by the variable timer 58. Thus, the size of the pistons 1 3 controls the amount of meat that can be forced into the apertures 1 2 above the pistons. The variable timer 58 controls the length of time the apertures 1 2 are lined up with the inlets 14 and the outlets 15, and the flow control valve 73 controls the speed of travel of the meat through the inlets and outlets.Thus, by varying the time the apertures 1 2 are open, and by varying the speed of the meat, infinite variation in the shape of the moulded portions can be achieved. The longer the period of opening and the slower the meat speed the more elongate the moulded portions, shorter periods and faster flowing meat leading to stubby moulded portions.

The meat supply cylinder 1 is held together by means of swivel bolts and hand nuts 32 (see Fig. 4). The thimble 10, the manifold 9 and the end cover 33 of the moulding head 3 are held together by captive hand screws 34 (see Fig. 1). The entire moulding head 3 is attached to the frame of the machine by means of toggle clips 35 (see Fig. 3). Thus, the parts of the machine that require frequent cleaning and sterilisation can be disassembled and re-assembled easily and quickly.

Obviously, the machine described above could be modified in many ways. For example, the number of arms on the timer turret could be modified to vary the number of rows of moulded meat portions. Similarly, the moulding head 3 could be modified by changing the number of moulding apertures 1 2 so as to vary the number of moulded meat portions in each row.

One important advantage of the machine described above is that the supply of pressurised air to the moulding head 3 is controlled in such a way that the air pressure is off when the barrel 11 is turning and on only when the meat is being pushed into (and out of) the apertures 1 2. Not only does this help with the relative rotation of the barrel 11 within the thimble 1O, but it also results in an improved product. Previously, when the meat pressure of about 30 p.s.i. was permanently on, the meat being moulded was permanently pressurised, and this gave rise to the possibility of the product exploding as it was pushed out of the head. The risk of such explosions is eliminated by this on/off control of the air pressure to the head.

Although the moulding machine described above is intended for moulding scampi meat, it will be apparent that it could be used to mould fillet-shaped pieces of wet fish such as cod or haddock. It could also be used for moulding mince, making sausages or steaklike meat portions from small pieces of meat or soya.

It should be noted that the four NOT units 52, 53, 70 and 71 are not all identical.

Claims (43)

1. A meat moulding machine comprising a moulding head, a meat supply cylinder for supplying meat to the moulding head, and control means for controlling the supply of meat to the moulding head and for controlling the operation of the moulding head, the moulding head comprising a thimble and a barrel rotatably mounted within the thimble, the barrel being provided with at least one moulding aperture containing a reciprocable piston, the or each moulding aperture being alignable with a respective inlet formed in the thimble and with a respective outlet formed in the thimble, wherein the control means is such that meat is supplied to the or each inlet whenever the corresponding aperture is aligned therewith.

2. A meat moulding machine as claimed in claim 1, wherein the control means comprises a control valve and a pneumatic control circuit.

3. A meat moulding machine as claimed in claim 2, wherein the control valve has three ports, a first of which is connectible to a meat supply hopper, a second of which is connected to the meat supply cylinder, and the third of which is connected to the moulding head.

4. A meat moulding machine as claimed in claim 2 or claim 3, wherein the control valve is actuated by means of a pneumatic control cylinder which forms part of the pneumatic control circuit.

5. A meat moulding machine as claimed in any one of claims 2 to 4, wherein the barrel is rotatable within the thimble, via a pawl-and-ratchet mechanism and a gear train, by extending or retracting a pneumatic head cylinder which forms part of the pneumatic control circuit.

6. A meat moulding machine as claimed in claim 5, wherein the head cylinder is actuatable by a pneumatic control valve.

7. A meat moulding machine as claimed in claim 6, wherein the pneumatic control valve is a lever-operated control valve.

8. A meat moulding machine as claimed in claim 6 or claim 7, wherein the control means is such that the barrel is rotated in 90 turns.

9. A meat moulding machine as claimed in claim 8, wherein alternate 90 turns are initiated by first and second arms of a rotatable timer turret actuating the pneumatic control valve.

10. A meat moulding machine as claimed in claim 9, wherein said first and second arms actuate the pneumatic control valve to extend the head cylinder, and a second pneumatic control valve is actuated when the head cylinder is fully extended to retract the head cylinder.

11. A meat moulding machine as claimed in claim 9 or claim 10, wherein the timer turret has three pairs of first and second arms.

1 2. A meat moulding machine as claimed in any one of claims 6 to 11, wherein the pneumatic control valve is mounted on the head cylinder, and is pressure-operated.

1 3. A meat moulding machine as claimed in any one of claims 2 to 12, wherein the meat supply cylinder is actuable by means of a pneumatic operating cylinder which forms part of the pneumatic control circuit.

14. A meat moulding machine as claimed in claim 1 3 when appendant to claim 10, wherein pressurisation of the operating cylinder is controlled by means of a third pneumatic control valve.

1 5. A meat moulding machine as claimed in claim 14, wherein the third pneumatic control valve is actuated by the head cylinder so that the operating cylinder causes the meat supply cylinder to supply meat to the moulding head when the head cylinder has rotated the barrel into a position in which the or each aperture is aligned with its inlet and outlet.

1 6. A meat moulding machine as claimed in claim 14 or claim 15, wherein means are provided for removing the air supply to the operating cylinder whenever air is supplied to the head cylinder.

1 7. A meat moulding machine as claimed in claim 16, wherein said air removing means is constituted by a fourth pneumatic control valve which is operated by the first pneumatic control valve when actuated by a second arm of the timer turret.

1 8. A meat moulding machine as claimed in claim 17, wherein the fourth pneumatic control valve is pressure-operated.

19. A meat moulding machine as claimed in any one of claims 1 to 18, further comprising a conveyor for moving trays under the moulding head.

20. A meat moulding machine as claimed in claim 19, wherein the conveyor carries pushers for pushing the trays one-by-one under the moulding head.

21. A meat moulding machine as claimed in any one of claims 2 to 20, wherein the pneumatic control circuit includes a pneumatic start valve and a pneumatic stop valve for starting and stopping respectively the moulding operation.

22. A meat moulding machine as claimed in claim 21 when appendant to claim 20, wherein the start and stop valves are leveroperated valves which are actuated by the pushers.

23. A meat moulding machine as claimed in claim 21 or claim 22, wherein the control means is such that six moulding operations occur between the actuation of the start valve and actuation of the stop valve.

24. A meat moulding machine as claimed in claim 1 9 or in any one of claims 20 to 23 when appendant to claim 19, wherein a fifth pneumatic control valve is provided for preventing moulding being initiated unless a tray is under the moulding head.

25. A meat moulding machine as claimed in claim 24, wherein the fifth pneumatic control valve is a lever-operated valve which is actuated by the passage of a tray thereover.

26. A meat moulding machine as claimed in any one of claims 2 to 25, wherein means are provided for controlling the period during which the or each aperture of the barrel is aligned with its inlet and outlet.

27. A meat moulding machine as claimed in claim 26, wherein said means is constituted by a pneumatic variable timer which forms part of the pneumatic control circuit.

28. A meat moulding machine as claimed in claim 1 3 when appendant to claim 5, further comprising means for preventing the head cylinder being pressurised before air is removed from the operating cylinder.

29. A meat moulding machine as claimed in claim 28, wherein said means includes a pneumatic fixed timer which forms part of the pneumatic control circuit.

30. A meat moulding machine as claimed in claim 1 3 or in any one of claims 14 to 29 when appendant to claim 13, wherein the pneumatic control valve circuit includes a pneumatic flow control valve for controlling the pressurisation of the operating cylinder.

31. A meat moulding machine substantially as hereinbefore described with reference to, and a illustrated by the accompanying drawings.

32. A moulding head for a meat moulding machine, the moulding head comprising a generally tubular thimble and a generally cylindrical barrel rotatable within the thimble, the barrel being provided with at least one diametrical moulding aperture containing a reciprocable piston, the or each aperture being alignable with a respective inlet and a respective outlet formed in the thimble, wherein the barrel is provided with two blades which contact the inner wall of the thimble adjacent the two ends of the or each moulding aperture.

33. A moulding head as claimed in claim 32, wherein the barrel is provided with seven parallel moulding apertures, each containing a reciprocable piston.

34. A moulding head as claimed in claim 33, wherein the thimble is provided with an inlet manifold for directing meat particles towards the moulding apertures.

35. A moulding head as claimed in any one of claims 32 to 34, wherein each of the pistons is formed with an elongate longitudinal slot, a rod passing through the slots in the pistons being provided for controlling the movement of the pistons in the moulding apertures.

36. A moulding head as claimed in any one of claims 32 to 35, wherein each blade is mounted in a slot formed in the barrel.

37. A moulding head as claimed in any one of claims 32 to 36, wherein each blade is made of non-toxic hard plastics material and is biassed outwardly towards said inner wall of the thimble.

38. A moulding head as claimed in claim 37 when appendant to claim 35, wherein resilient non-toxic rubber strips are provided for biassing the blades, each resilient nontoxic rubber strip being positioned between the base of the respective slot and the adjacent end of the respective blade.

39. A moulding head as claimed in claim 38, wherein the blades are held in position by means of non-toxic rubber rings fitted to the ends of the barrel.

40. A moulding head for a meat moulding machine, the moulding head comprising a generally tubular thimble and a generally cylindrical barrel rotatable within the thimble, the barrel being provided with at least one diametrical moulding aperture containing a reciprocable piston, the or each aperture being alignable with a respective inlet and a respective outlet formed in the thimble, wherein the barrel is rotatably mounted in the thimble by means of low friction pads mounted in, and extending slightly beyond, the outer cylindrical surface of the barrel.

41. A moulding head as claimed in claim 40, wherein the barrel and thimble are made of stainless steel.

42. A moulding head a claimed in claim 41, wherein four pads are positioned at each end of the barrel, each pad being mounted in a hole in the cylindrical surface of the barrel.

43. A moulding head for a meat moulding machine, the moulding head being substantially as hereinbefore described with reference to, and as illustrated by, Figs. 1 to 8 of the accompanying drawings.