EP0306012B1 - Method and apparatus for slicing food products - Google Patents

Abstract

In a method for cutting slabs of meat into portions of uniform weight, the slab of meat (36) is first pressed in a shaping press (14) to the desired cross-sectional shape and then, from an open end of the shaping cavity, is pressed against a stop surface at the other open end by means of a plunger (16). In this way, the shaping cavity is completely filled. The compressed slab is then advanced in steps and cut into slices by means of a knife (18). <IMAGE>

Description

The invention relates to a method for cutting strands of food according to the preamble of claim 1, and an apparatus for performing this method.

Up to now, meat, for example schnitzel, roulades, chops or the like, has mostly been cut by hand, the cuts being made in such a way that portions with at least approximately uniform weight are produced.

US-A-4,356,205 shows and describes a method according to the preamble of claim 1 and an apparatus according to the preamble of claim 2, in which meat strands are pushed against an abutment plate in an open, inclined groove by a thrust member, for example a weight. Before the stop plate, the meat strands are gripped in the radial direction by jaws, brought to a uniform cross section and cut.

A method is also known in which the meat strand is first frozen at a temperature of approximately -2 to -4 ° C. and then pressed to a uniform cross-sectional shape in a suitable molding press. The slightly frozen meat also remains after removal from the press the uniform cross-sectional shape and can then be cut into uniform portions using a slicer or slicer. However, this method is relatively cumbersome and time-consuming and requires the use of at least two workers, one of whom operates the molding press and the other the slicing machine, in the case of assembly line production in large companies.

The invention has for its object to provide a simpler and more efficient method for cutting strands of meat or other strands of food, which nevertheless allows an exact maintenance of the desired weight. Another object of the invention is to provide a suitable device for carrying out this method.

The achievement of this object results from claim 1 and the device claims.

In the method according to the invention, the strand is pressed in the molding press and when the mold is closed with the aid of a piston which can be inserted axially into the mold with a predetermined pressure against a deflection surface arranged on the opposite strand end, so that the meat strand is compressed to a minimum volume. The knife is then moved into a waiting position in which it releases the meat strand, the strand is advanced by a certain amount with the aid of the piston, and the protruding end of the strand is cut off with the knife. After the cut, the knife is stopped in the waiting position and the strand is advanced again so that the next slice can be cut off. These processes are repeated periodically until the entire strand is cut open. During the entire process, the strand enclosed in the molding press and between the piston and the knife maintains its compact shape, so that the uniform cross section is maintained and no voids can arise in the meat. Since both the volume determined by the constant cross-section and the feed path and the density of the meat are constant, the cut slices have a uniform weight within narrow tolerances.

According to a first embodiment, this stop surface is a side surface of a knife, the strand then releases so that it can be advanced by a predetermined amount with the aid of the piston, then rotates once and cuts off the projecting end of the strand. To ensure that the end of the strand does not expand significantly after being released by the knife, the cycle time must be very short, in particular less than 1/2 second. Otherwise, this embodiment of the invention is particularly suitable for relatively solid and consistent clippings.

According to another embodiment, the strand inside the molding press is pressed with the aid of the piston against a stop surface formed by a counter-piston. The counter-piston is located on the other side of the knife level and is located within two catch jaws that open and close transversely to the direction of the strand and form a cavity that corresponds to the internal cross-section of the molding press, the cavity of which is thus somewhat extended. There is a small space between the molding press and the collecting jaws through which the knife can rotate.

It is not necessary to freeze the meat beforehand in the method according to the invention and when using the device according to the invention, but processing of frozen meat is also possible. This improves the results, in particular in the first embodiment of the invention.

After cutting, the chips are mostly transported to a breading device with the aid of a conveyor belt. In the method according to the invention, the cutting frequency is relatively high in relation to the throughput speed of the chips through the breading device, so that it is expedient to rearrange the chips on the conveyor belt between the cutting device of the breading device in such a way that several chips enter the breading device simultaneously. Furthermore the remaining pieces after the complete cutting of a strand must be sorted out on the conveyor belt, since these do not have the intended weight. The conveyor belt is preferably controlled in dependence on the working rhythm of the cutting device such that this sorting work can be carried out by the operator for the cutting device. For this purpose, the conveyor belt is driven continuously during the cutting processes. However, as soon as the strand is cut open and the piston moves back to the starting position, the conveyor belt is stopped, so that the operator has time to insert a new strand of meat and to put the cutting device into operation again before continuing the sorting work. However, these considerations are not the subject of the present invention. The method according to the invention can also be used to cut strands of meat containing bone, for example cutlets. In this case, the molding press is preferably equipped with jaws, the shape of which is adapted approximately to the cross-sectional shape of the strand. The piston can also be adapted to this cross-sectional shape by means of a suitable extension piece. The axial contact pressure of the piston is adjusted in such a way that cartilage parts, such as the intervertebral discs in a chop strand, are pressed firmly together, but breakage of the bones is avoided.

Further advantageous refinements of the method and the device according to the invention are specified in the subclaims.

A preferred exemplary embodiment of the invention is explained in more detail below with reference to the drawings.

Fig. 1

eine erfindungsgemäße Schneidvorrichtung in der Draufsicht;

Fig. 2

eine Ansicht einer Formpresse und eines Messers der Schneidvorrichtung;

Fig. 3

einen Schnitt durch einen Kolben der Formpresse;

Fig. 4

ein Ansatzstück für den Kolben; und

Fig.5 - 7

die Teildarstellung einer zweiten Ausführungsform.

Show it:

Fig. 1

a cutting device according to the invention in plan view;

Fig. 2

a view of a molding press and a knife of the cutting device;

Fig. 3

a section through a piston of the molding press;

Fig. 4

an extension for the piston; and

Fig. 5 - 7

the partial representation of a second embodiment.

A cutting device 10, for example for chips, comprises a drive unit 12, a molding press 14, a piston 16 which can be inserted axially into the molding press and a wing-like knife 18 which is rotatably arranged on an end face of the molding press Cutting device 10, a removal device 22 and a conveyor belt 24 are arranged. Optionally, however, a container for collecting the chips can also be provided below the knife 18 of the cutting device.

According to FIG. 2, the molding press 14 comprises a fixed base plate 26 and a jaw 28 which is firmly screwed thereto, and a jaw 30 which can be slid on the base plate 26 and which carries a cover plate 32 which is firmly screwed to the upper end. The base plate 26 and the jaws 28, 30 consist of food-compatible plastic, while the cover plate 32 is made of stainless steel. The jaws 28, 30 each have an approximately semicircular hollow 34, so that an inserted meat strand 36 (FIG. 1) is pressed into a circular or oval cross-sectional shape. When the molding press is closed, the cover plate 32 slides onto the upper surface of the fixed jaw 28, so that the compressed one dodges Meat is prevented upwards. The cutting edge-shaped lower edge 38 of the movable jaw 30 slides over the base plate 26 without a gap.

As can be seen in FIG. 1, the movable jaw 30 is provided on its upper side with two guide bushes 40 and guided on guide rods 42. The drive for the movable jaw 30 is arranged, for example, below the base plate 26 and connected to the jaw through a slot 44.

The piston 16 has a circular cross section adapted to the cavity 34 of the jaws 28, 30, but can be enlarged when processing larger meat strands by means of an extension piece 46 indicated by a dash-dotted line in FIG. 1. In the middle of its end face, the piston 16 has a projecting, spring-supported pushbutton 48.

As can be seen in FIG. 3, the pushbutton 48 is held in its position by an end plate 50 screwed onto the piston 16. Two screws 52 projecting from the push button are used for axial guidance, which engage in channels of the piston body and are surrounded by disc springs 54 for pretensioning the push button. When the pushbutton 48 is pushed back into the interior of the piston 16 by the meat strand 36 against the force of the plate spring 54, one end of one of the screws 52 actuates a magnetic switch 56. In this way it is indicated that the piston has the desired contact pressure on the meat strand exercises.

The extension piece 46 shown in detail in FIG. 4 can be plugged onto the piston from the side and has a cavity 58 adapted to the peripheral surface of the piston. A detachably fastened in the extension, projecting from the bottom of the cavity 58 bolt 60 engages in a radial bore 62 of the piston 16, so that the extension is stably supported and held securely in position.

According to FIG. 2, the knife 18 is mounted on a knife shaft 64, which is arranged laterally next to the molding press 14, preferably above the base plate 26, so that no cleaning liquid penetrates into the bearings of the knife shaft when the molding press is cleaned. The knife has an arcuate cutting edge 66 and moves during a cutting operation directly past the ends of the jaws 28, 30 received in a window 68 of a housing wall 70, so that the protruding end of the meat strand is cut cleanly with a pulling cut.

The removal device 22 and the conveyor belt 24 have a conventional construction and are therefore not to be described in detail.

The drive unit 12 of the cutting device 10 has a motor 72 which can be driven in opposite directions for driving the piston 16 and a further motor 74 which can likewise be driven in opposite directions for driving the movable jaw 30, the knife 18 and the removal device 22. The motor 72 is connected to a spindle drive 80 for the piston 16 via a drive belt 76 and a magnetic coupling 78. The motor 74 drives a transmission shaft 82, which in turn is connected via couplings 84 and drive belts 86, 88, 90 to drive shafts 92, 94 for the movable jaw 30 and the removal device 22 and to the cutter shaft 64. The motors 72, 74 and the clutches 78, 84 are controlled by a control unit 96, which uses sensors such as limit switches and the like to determine the respective positions of the driven components of the device.

The mode of operation of the device described above will be explained below.

When the molding press 14 is open, the meat strand 36 is inserted and the device is started. The movable jaw 30 is advanced in the direction of the fixed jaw 28 until a limit switch 98 (FIG. 2) attached in the cavity 34 of the jaw 30 strikes the circumference of the piston 16 or the extension piece 46 and indicates the complete positive locking. During this process, the meat strand 36 is compressed to a uniform cross-sectional shape over its entire length. The knife 18 is in a position in which it closes the cavity of the molding press 14.

After the jaw 30 has stopped, the piston 16 is advanced so that the meat strand 36 supported on the knife 18 is also compressed in the axial direction. When the magnetic switch 56 indicates that a certain contact pressure has been reached, the piston 16 is stopped and the knife 18 is moved into the waiting position shown in FIG. Subsequently, the piston 16 is advanced by a certain preset path with the aid of an NC control contained in the control unit 96, so that the meat strand 36 is pressed out of the molding press by a corresponding path. The knife shaft 64 is driven again so that the knife 18 describes a complete circle and cuts off the end of the meat strand 36 with a corresponding swing. The strand of meat is then advanced again by the same amount, while the knife 18 is stopped in the waiting position until the next cut is made. By alternately advancing the strand and operating the knife, the entire meat strand is cut open little by little. The cut chips 20 are taken over by the receiving device 22 in the working cycle of the cutting device 10 and transferred to the continuously running conveyor belt 24. On the relatively slow-running conveyor belt 24, the chips are arranged next to one another in several rows by an operator. If it is sensed by a limit switch that the piston 16 has reached its end position, the piston is withdrawn into the starting position and the molding press open. During the backward movement of the piston, the conveyor belt 24 is stopped, so that the operator can interrupt the sorting work and insert a new strand of meat into the molding press 14. The conveyor belt is only put into operation again when the cutting processes are reinserted, so that the operator can continue his sorting and monitoring work.

During the cutting operations, the motors 72, 74 of the drive unit 12 are in continuous operation. The movement sequences are controlled by actuating the magnetic clutches 78, 84, which act as brakes when disengaged and hold the driven part in the desired rest position until the movement is resumed. A high clock frequency is achieved in this way. Only a fraction of a second passes between the release of the end face of the meat strand 36 by the knife 18 and the execution of the next cut, so that practically no deformation of the meat occurs during this time.

Instead of the spindle drive for advancing the piston 16, a hydraulic cylinder can be provided in the interest of a higher working speed.

FIGS. 5 to 7 illustrate an embodiment of the invention which is advantageous in the interest of more precise portioning, in particular in the case of meat which has not previously been frozen. The device explained below is based on the embodiment shown in FIG. 1. However, the removal device 22 is omitted. On the other hand, the additional devices shown in FIGS. 5 to 7 are provided in front of the front housing wall 70 in the region of the exit position of the meat strand 36.

FIG. 5 is a front view of the modified embodiment, that is to say a view from below in FIG. 1. FIG. 6 is an associated top view, and FIG. 7 shows a corresponding side view.

On the housing wall 70, on both sides of the outlet openings of the meat strand 36 blocks 100, 102 are fastened, which carry two horizontal, parallel, superimposed guide rods 104, 106. Collecting jaws 108, 110, which can be displaced in the horizontal direction, are guided on the guide rods 104, 106, each of which consists of guide pieces 112, 114 and inner, facing inserts 116, 118. The inserts 116, 118 together form a recess 120 which, according to FIG. 5, has a circular cross section which corresponds to the cross section of the cavity formed by the jaws 28, 30 and with which the recess 120 is aligned. As with the jaws 28, 30, the recess 120 of the inserts 116, 118 can also have a different cross-sectional shape, if this is desired.

Pneumatic cylinders 122, 124 are fastened to the outside of the trestles 100, 102, the inward-facing piston rods 126, 128 thereof being connected to the associated guide piece 112, 114. The pneumatic cylinders allow the inserts 116, 118 to be pulled apart and pushed together and thus the opening 120 to be opened and closed in cycles.

5 and 6, an L-shaped arm 130 is attached to the housing wall 70, the free leg 132 of which extends to the recess 120. A spindle 134 lying in the axis of the recess 120 penetrates the end region of the leg 132 with threaded engagement and carries a counter-piston 136 lying inside the recess 120. A handwheel 138 is fastened to the outer end of the spindle 134, which is at the bottom in FIG. 6. By adjusting the piston 136 With the help of the handwheel 138, the volume of the cavity 114 delimited by the inserts 116, 118 and the counter-piston 136 can be changed. Instead of the spindle 134 and the handwheel 138, another adjustment mechanism, for example a hydraulic cylinder, can be provided.

In front of the housing wall 70, a vertically upstanding support plate 142 is fastened above the outlet opening of the meat strand 36, on which a pneumatic cylinder 146 is held via a holder 144, the piston rod 148 of which is directed vertically downward. A downward ejector 150 is attached to the lower end of the piston rod 148.

The previously described embodiment works as follows:
While in the embodiment described initially the cavity formed by the jaws 28, 30 and the piston 16 is closed to the front when the meat strand is pressed together by the knife 18, in the second embodiment this is done with the aid of the catch jaws 108, 110 and the counter-piston 136. The knife 18 is in the waiting position. When the pressing process is finished, the knife 18 is set in motion and the meat strand is cut in the space between the housing wall 70 and the inserts 116, 118. To compensate for the displacement of the clippings by the knife, the piston 16 can be pulled back a short distance in accordance with the knife thickness immediately before the cut. The volume of the cut pieces of meat can be adjusted using the spindle 134 and the counter piston 136. After the cut, the catch jaws 108, 110 are pulled apart laterally with the aid of the pneumatic cylinders 122, 124, and the cut piece of meat, which under certain circumstances still adheres to the meat strand 36 or also the counter-piston 136, is pressed down with the aid of the ejector 150.

The opening and closing movements of the catch jaws 108, 110 and the lowering movement of the ejector 150 take place in time with the rotation of the knife. After the catch jaws have closed, the piston 16 is advanced one step at a time.

The controller 96 can be a CNC controller that largely automatically regulates the individual movement sequences.

Before filling a new piece of meat, it can be weighed on a scale assigned to the machine. The CNC control can offer different possibilities for adjusting the feed of the piston 16. On the one hand, it can divide the determined weight in such a way that the piece of meat inserted is completely consumed and slices are formed which are as close as possible to a predetermined target weight. On the other hand, an exact target weight can also be set, provided that a remainder can be accepted. In addition, under certain circumstances it can also be provided that the computer optimally distributes a piece of meat with different target weights that are considered.

Claims (10)

1. Method for slicing food products, in particular rolls of meat, into portions with a predetermined weight, in which the roll (36) is forced axially against a stop and is pressed by means of a moulding press (14) transversely to the roll into a uniform cross-sectional shape, and is then cut into slices as gradual axial displacement takes place, characterised in that the roll (36) pressed into the required cross-section is compressed axially before being cut in the sealed moulding press (14) at predetermined pressure against the stop surface (18,136).
2. Apparatus for performing the method according to Claim 1, with a moulding press (14) which opens and closes in the transverse direction of the roll (36), a component (16) which exerts an axial force on the roll (36) axially from one end in the moulding press, and a stop surface (18,136) which closes the other end of the moulding press (14), characterized in that the moulding press (14) is designed to open and close fully along the roll (36) and has a piston (16) which can be inserted in the moulding press (14) and produces the axial force.
3. Apparatus according to Claim 2, characterised in that the stop surface is the lateral surface of a blade (18) which cuts the roll.
4. Apparatus according to Claim 2, characterised in that the blade (18) is disposed rotatably on a plane between the piston (16) and the stop surface (136) in the area of the front of the moulding press (14) opposite the piston (16); and in that relative to the blade plane, opposite the piston (16) there are provided two collector jaws (108,110) which delimit a cavity (140) corresponding to the cross-section of the interior of the moulding press and which open and close transversely to the direction of the roll, which cavity is delimited on the side facing away from the blade (18) by an adjustable counter-piston (136).
5. Apparatus according to Claim 4, characterised in that the collector jaws (108,110) are displaceable in the direction of the roll, and produce a gap for an ejector (150) which can be lowered and is disposed above the collector jaws (108,110).
6. Apparatus according to any one of Claims 2 to 5, characterised by a sensor device (48,56) disposed on or in the piston (16), for sensing the pressure of the piston against the roll of meat.
7. Apparatus according to any one of Claims 4 to 6, characterised in that the cross-section of the piston (16) and optionally of the counter-piston (136) is adjustable by means of a joining piece (46) attachable laterally.
8. Apparatus according to any one of Claims 4 to 7, characterized in that for opening and closing the moulding press (14), jaws (28,30) which are displaceable towards each other are provided, and in that the jaws (28,30) and optionally also the collector jaws (108,110) are interchangeable for adaptation to the cross sections of various rolls.
9. Apparatus according to any one of Claims 2 to 8, characterised by a CNC control unit (96) for coordinated control of the displacement paths.
10. Apparatus according to Claim 9, characterised in that scales for weighing the rolls of meat inserted are associated with the CNC control unit (96); and in that the CNC control unit includes a calculating unit which controls the piston (16) optionally for accurate maintenance of a predetermined slice weight, or for complete distribution of a roll of meat inserted, into slices of an equal weight, thus departing from the predetermined slice weight.

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