Patent Abstract:
The invention relates to a calibrated cutting device for slicing foodstuffs that are suitable for cutting, more particularly meat products. Said device has the following characteristics: a base frame ( 1 ) is provided; a shaping tube ( 55 ) is also provided, through which the food product that is to be sliced is moved forward in the direction of a calibrated cavity ( 49 ); the calibrated shaping cavity ( 49 ) is a separate constructive unit different from the shaping tube ( 49 ); a knife arrangement ( 65 ) moving lengthwise is provided between the feed hole ( 31 ) of the calibrated shaping cavity ( 49 ) and the adjacent delivery hole ( 63 ) of the shaping tube ( 55 ), which is arranged between the calibrated cavity ( 49 ) and the shaping tube ( 55 ); a clamping unit ( 13 ) is also provided. The shaping tube ( 55 ) and the calibrated shaping cavity ( 49 ) can be pressed together by means of the clamping device ( 13 ) in order to achieve a negative pressure on the shaping tube ( 55 ) through the calibrated shaping cavity ( 49 ).

Full Description:
BACKGROUND OF THE INVENTION 
     In many areas of foodstuffs technology, it is desirable for certain amounts of foodstuffs to be prepared in portions which are as accurate as possible. 
     While the portioning of liquid or free-flowing materials takes place without problems or substantially without problems, the portioning of foodstuffs which do not flow has to be considered to be something other than optimum. 
     For example, during the production and further processing of meat products, it would be desirable if, for example, beef, pork or turkey meat could be cut and prepared in portions which are as identical as possible. Correspondingly equally sized portions of meat could then be processed further or sold optimally. 
     Corresponding calibrating devices have also been disclosed, for example, for shaped and processed meat, in which the meat is initially processed and pressed together again in such a manner that it assumes a certain shape. However, for the time being this requires the stringy meat to be processed into very small pieces or involves utilizing meat residues. 
     A calibrated cutting installation having a shaping tube for feeding the meat to a cutting device in order to separate meat into portions which are as far as possible of equal size by means of a cutter has already been disclosed. The shaping tube can be separated into two parts in the longitudinal direction. The end of the shaping tube, at a so-called delivery hole, is adjoined by a pot-shaped or shell-shaped depressions, the size and volume of which predetermine the corresponding portion. Then, a cutter can be moved through a in a spacer gap between the feed hole of the shaping tube and the abovementioned calibrated shaping cavity, the oblique arrangement of the cutting edges of which cutter causes a pulling cut, with the result that the corresponding amount of meat situated in the calibrated shaping cavity can be separated from the large remaining amount of meat situated in the shaping tube. 
     Then, the pot-shaped calibrating plate can be moved in order, if appropriate by means of further auxiliary measures, to remove the amount of meat which is situated in the calibrating cavity from the calibrating cavity and, for example, to deliver it to a conveyor belt. 
     However, the calibrated cutting device just mentioned has a number of drawbacks. 
     It has emerged that it is not always possible to ensure that the calibrating cavity is filled as uniformly as possible with the known calibrated cutting device. This is despite the fact that the calibrating cavity is designed more in the shape of a soup-dish, i.e. has a concave curve at the transition from the base area to the side wall area, avoiding a sharp edge, so that, as far as possible, inclusions of air are prevented. In addition, vacuum suction lines emerge from the area of the base of the calibrating cavity, in order to use a further suction device to pull in each case the next portion of meat optimally into the calibrating cavity. However, in this case too it has been found that the meat which is to be processed partially closes the suction passages which are present, so that air bubbles which are situated at a different location between the meat portion and the calibrating cavity cannot be sucked out. Ultimately, this leads to the size and weight of the meat portions which are to be separated differing considerably, at least in relative terms. 
     In view of the above, working on the basis of the abovementioned prior art, the object of the invention is to provide an improved calibrated cutting device which can be used to portion foodstuffs that are suitable for cutting, in particular meat, as optimally as possible, with the minimum possible weight and/or volume discrepancies. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is explained in more detail below with reference to an exemplary embodiment, in which, in detail: 
     FIG.  1 : shows a diagrammatic, longitudinal side view through a vertical, central longitudinal section through the calibrated cutting device; 
     FIG.  2 : shows a diagrammatic, horizontal plan view at the level of the cutter, with a shaping tube having been omitted; and 
     FIG.  3 : shows an enlarged detailed view from FIG.  1 . 
    
    
     DESCRIPTION OF THE INVENTION 
     With the present invention, relatively simple means are used to achieve considerable improvements over the prior art. 
     Thus, it has emerged that the structure and the functioning of the vacuum for pulling the next meat portion into the calibrating cavity can be decisively improved by the fact that a connection which is as far as possible vacuum-tight can be produced between the delivery hole of the shaping tube and the adjoining feed hole of the calibrating cavity. As a result, the feed movement of the meat situated in the shaping cavity is supported by the sucking action of the vacuum for which reason the importance of a press ram which can additionally be moved in the advancement direction from the rear side in the shaping cavity is lowered and reduced. According to the invention, this is achieved by means of a pressure-exerting or clamping device which, at least during certain working cycles of the calibrated cutting device, at least indirectly presses the calibrated shaping cavity and the delivery hole in the shaping tube together, so that in this area the desired pressure reduction is maintained further and can continue to act in the shaping tube. 
     In a preferred embodiment of the invention, the cutter used is a perforated cutter, the size of perforations of which at least corresponds to the size and shape of the feed hole of the calibrating cavity. Then, during the cutting stroke, the perforated cutter is moved in the longitudinal direction between the output hole in the shaping plate and the support surface of the calibrating plate which accommodates in the calibrating cavity. Moreover, the use of the perforated cutter further assists with building up the abovementioned vacuum, since the perforated cutter is arranged with an encircling section of material between the output hole of the shaping tube and the feed hole of the calibrating plate which accommodates in the calibrating cavity. 
     The cutter is preferably of the same shape as the calibrating plate and may in this case be ground from solid tool steel. In the trailing area, that is to say in the cutting direction, it is preferably provided with two blades which are directed at an angle to one another. The thickness of the cutter can be selected to be extremely thin, preferably ranging between 0.5 mm and 3 mm. 
     However, the pressure between calibrating cavity and shaping cavity, preferably with the inclusion of the perforated cutter situated between them, is not only a prerequisite for a continuous, optimum vacuum to be applied, but also it prevents a smearing effect of the cutter, which represents a drawback. This is because, according to the invention, the clamping action means that an extremely thin cutter can be used, having the further advantage that in the area of the volume which corresponds to the thickness of the cutter material it is virtually impossible for any residual quantities of meat to remain, since the wedge effect of the cutter is only minimal, due to its small thickness. 
     The calibrated cutting device shown in the figures comprises a base  1 , which is also referred to below as a base frame. 
     A pressure-exerting plate  3  is fitted in the area of one end side of the base frame  1 , which is rectangular in plan view, which pressure-exerting plate has a cylindrical bore  5  which faces upward and in which a cylindrical mating piece  7  of a vacuum plate  9  engages. 
     By means of the cylindrical mating piece  7 , which engages in the cylindrical bore  5 , of the vacuum plate  9 , a pressure chamber  11  of a clamping unit  13  is created, the importance of which will be dealt with below. 
     By means of a compressed-air port  17  with a following pressure line  19 , compressed air can be fed in controlled amounts to the pressure chamber  11  of a compressed-air source (not shown in more detail). 
     The abovementioned vacuum plate  9  has a reduced-pressure chamber  21  which is in communication with a suction port  25  via a suction line  23 . A vacuum valve  27 , which is only indicated in FIG. 1, is also fitted in the suction line  23 . 
     An inlay plate  31 , which is offset at a higher level with respect to the base of the reduced-pressure chamber  21  by means of feet or spacers  33 , is inserted in the reduced-pressure chamber  21 . The top side  31 ′ of the inlay plate  31  is approximately flush with the surface  35  of the vacuum plate  9  or is arranged only—preferably only fractions of a millimeter—lower than the surface  35  of the vacuum plate  9 . 
     In plan view, the shape and dimensions of the inlay plate  31  are designed in such a way with respect to the dimensions and shape of the reduced-pressure chamber  21 , likewise in plan view, that only an extremely small gap is formed between the periphery edge  39  of the inlay plate  31  and the adjacent, encircling wall surface  43  of the reduced-pressure chamber  21 ; this gap may, for example, be between 0.05 and 2 mm, preferably between 0.1 and 1 mm, in particular between 0.2 and 0.6 mm. In the exemplary embodiment shown, a gap width of 0.3 mm is selected. In the exemplary embodiment shown, the gap height is 5 mm, corresponding to the thickness of the actual inlay plate  31  situated above the feet  33 . These small dimensions of the gap  37  ensure that it is impossible for any relatively large meat particles to be sucked out during the calibration and cutting operation (FIG.  3 ). 
     A calibrating plate  47 , which is shown in its basic position in FIGS. 1 to  3  and comprises a hollow or calibrated shaping cavity  49  which surrounds by the material of the calibrating plate  47  in plan view and is open at the top and bottom, rests on the surface  35 . The feed hole  51 , which faces upward, and the horizontal cross-sectional shape and dimensions of this shaping cavity correspond to the horizontal cross-sectional shape and dimensions of a shaping tube body  53  which is arranged above the calibrating plate  47  and has a shaping tube  55 , which is situated vertically in the interior and from the top, charging side  57  of which meat to be portioned can be supplied and pushed downward via a press ram  61  which is arranged above the charging hole  57  and can be actuated by means of a press cylinder  59 . In plan view, the shaping tube is oval in cross section, namely with an oval hole  55 ′, as can be seen in the plan view shown in FIG.  2 . Apart from the cutting edges  65 ′ which are aligned in the shape of a wedge, this oval shape  55 ′ also corresponds to the cross-sectional shape and size of the calibrated shaping cavity  49 . The shaping tube  55  or the shaping tube body  53  may be formed form a plurality of plates with corresponding recesses, which can be laid on top of one another, the shaping tube body  53  or the individual plates which form this body being held by two side guide columns  71  which are connected to the base  1  and are held securely above it. Alternatively, the shaping tube body may also be divided in two in its longitudinal axis, for example in the form of two half-shells. 
     Since the lower surface of the shaping tube body  53  serves as a sealing surface with respect to the cutter  65 , the lower bearing or sealing surface  66  of the shaping body  55  has to cover the V-shaped cutout  67  of the cutter  65  in the starting or filling position. 
     As can be seen from FIG.  1  and in particular from the enlarged, vertical cross-sectional view shown in FIG. 3, the shape and dimensions of the hole in the vacuum or reduced-pressure chamber  21 , which accommodates the inlay plate  31 , are slightly larger than the horizontal cross-sectional shape and dimensions of the hollow or calibrated shaping cavity  49  in the calibrating plate  47  and/or the horizontal cross-sectional shape or dimensions of the shaping tube  55 . 
     Finally, a cutter  65 , i.e. a perforated cutter  65 , is provided between the calibrating plate  47 , resting on the latter, and the underside of the shaping tube body  53 , which cutter is of approximately rectangular design in plan view, i.e. is in the shape of a plate, and comprises a cutting hole  67  (FIG.  2 ), which at least corresponds to the size and shape of the delivery hole  63  of the shaping tube  55  and/or the feed hole  51  of the calibrated shaping cavity  49 . In the exemplary embodiment shown, the cutting edges, in plan view, are of V-shaped design in the leading cutting direction (FIG.  2 ), the two cutting edges  65 ′, which are in a V shape with respect to one another, coming together in the central longitudinal axis of the rectangular perforated cutter  65 . The two cutting edges  65 ′ run, for example, at a 45° angle to the central longitudinal plane of the cutter, i.e. they include an angle of approximately 90° with one another, i.e. include an angle of approximately 90° with respect to one another and, in this way, produce a pulling cut. The inclination of the cutter may also vary to a correspondingly great extent, for example by at least up to +/−30° and more. Alternatively, it is also possible to provide exchangeable blades  65 ′ in a cutter body. 
     However, as an alternative to a cutting arrangement which can be moved to and fro, in principle a rotating cutting device is also conceivable. For example, it would be possible to use a disk-like cutting device which comprise closed cutting holes which are offset with respect to one another in sectors and the size and function of which correspond to the cutting hole described above; to carry out a cutting operation, a movement of the cutter along a circle or part of a circle with an axis of rotation which is outside the cutter hole would have to be executed. In this case, a continuous rotary movement of the cutting device, at least in steps, would be possible if all the cutting holes in the rotating perforated cutter have trailing cutting edges. 
     On that side of the base frame  1  which is opposite from the shaping tube body  53 , there may, in addition to control elements and devices, additionally be at least two cylinders  73  and  75 , namely a cutter cylinder  73  for moving the perforated cutter  65  forward and backward as illustrated by the arrow  77  and a calibrating cylinder  75  corresponding to the adjustment movements of the calibrating plate  47 , likewise in the direction of arrow  77 . For this purpose, the two calibrating cylinders  75 ,  77  are fixedly connected to the cutter  65  and the calibrating plate  47  by means of clamping/holding elements  75 ′. 
     The cutter is preferably of the same shape as the calibrating plate and consists of and is ground from a solid tool steel. The thickness of the cutter may vary within suitable ranges, for example from 0.3 mm to 5 mm, preferably may vary from 0.5 mm to 1.0 mm. Like the calibrating plate (which will be dealt with in more detail below), the cutter also moves at a right angle to the vertically oriented shaping tube  55 . 
     The method of operation is dealt with below. 
     Since, as is customary, cleaning has been carried out according to the extent to which the overall device can be broken down, the device can then be reassembled and put into operation. A suction hose is connected to the suction port  25 , and a compressed-air hose is connected to the compressed-air port  17 , which hoses are connected to corresponding vacuum and compressed-air devices. 
     Furthermore, three further hose ports are provided. One hose port is required in order to restore the plunger of the vacuum valve, since when the cutter reaches its extended limit position following the cutting operation (or shortly before), a valve plunger of the valve arrangement  27  is turned and the vacuum supply to the reduced-pressure chamber is interrupted. Then, the calibrating plate is extended forward. The cylinder outlet air is additionally utilized in order to ventilate the vacuum chamber. In this way, the pressure reduction which is present in the vacuum chamber is eliminated more quickly. The elimination of the pressure reduction prevents a sucking action from the vacuum chamber still being present when the calibrating plate is pushed out. The further hose port mentioned above serves as an air port for the vacuum chamber in order for compressed air to be pumped in here. The final hose port serves as the pressure connection to the vacuum chamber, in order to accommodate a vacuum switch in this hose port so as to measure the pressure in the vacuum chamber. 
     To portion relatively large amounts of meat, a suitable piece of meat is passed through the charging hole  57  from above into the shaping tube  55 , the pressure reduction which has been generated by a vacuum device (not shown in more detail) and is active in the reduced-pressure chamber  21  pulling the piece of meat further into the shaping tube  55 . The advancement movement of the piece of meat is assisted by subsequent actuation of the press cylinder  59 . 
     As a result of the pressure reduction generated in the reduced-pressure chamber  21  and the advancement movement of the press ram  61 , the leading area of the piece of meat which is to be portioned is moved downward until the front part of the piece of meat which is to be portioned completely fills the hollow or calibrated shaping cavity  49 . However, due to the extremely small gaps  37 , it is impossible for any meat to penetrate into or be sucked out through the vacuum and suction gaps  37 . 
     The desired pressure reduction for assisting with the advancement movement of the meat to be portioned and the complete filling of the calibrated shaping cavity  49  by the meat is primarily assisted and ensured by the fact that the entire arrangement of shaping tube body  53 , perforated cutter  65  and the calibrating plate  47  situated beneath it is subjected to preliminary pressure and clamped together by the clamping device  13  with the pressure-exerting and vacuum plate (explained at the beginning) in the manner of an assembly so that as far as possible there can be no ambient pressure penetrating into the reduced-pressure area, causing a loss of the pressure reduction. Since, moreover, a perforated cutter is used, it is also impossible for any atmospheric pressure to pass into the reduced-pressure area in the region of the cutter. Moreover, due to the abovementioned guide columns  71 , the shaping tube body  53  is held securely and non-displaceably with respect to the base  1 , as a pressure-exerting abutment, in order that the clamping unit  13  formed in this way can be optimally pressed together accordingly. 
     As soon as a piece of meat to be portioned has filled the entire calibrated shaping cavity  49 , a vacuum switch  27  which is in communication with the reduced-pressure chamber  21  can be used to establish a change in the pressure reduction. Furthermore, the cutter cylinder  73  can then be triggered and actuated, this cylinder being extended in the cutting direction and, in the process, separating the amount of meat which is situated in the calibrated shaping cavity  49  from the amount of meat which is situated in the shaping tube body  53 . In the device described, the clamping device  13  is permanently exposed to pressure and clamped in place, providing the further advantage that it is possible to use an extremely thin cutting plate or cutting disk. The clamping device which is under pressure protects the thin metal sheet of the cutter from becoming deformed, and the cutter is also stabilized by the opposite wall sections of the underside  66  of the shaping tube body  53  or the top side of the calibrating plate  47 . 
     As soon as the cutter has reached its front limit position, i.e. at least when the cutting hole  67  has fully traversed the feed hole  51  in the calibrated shaping cavity  49 , the calibrating cylinder  75  and therefore the calibrating plate  47  are likewise made to advance. As soon as the calibrated shaping cavity  49  has moved beyond the vacuum plate, the meat can be passed, for example downward, to a delivery station, for example an outgoing conveyor belt, etc., either by its own weight or by means of an additional ejector device. A simple auxiliary device which ejects the portioned meat may, for example, comprise levers which press the meat downward out of the calibrating mold. The ejector device may also be a short, sufficiently strong air stream which can be generated, for example, by cylinder outlet air. Other ejector devices are also possible. 
     Then, for preference, firstly the calibrating plate and then the perforated cutter move back into their starting position shown in FIGS. 1 to  3  and the operation repeats itself, i.e. after the starting portion of the cutter  65  and the calibrating plate  47  has been reached, firstly the clamping device  13  is confirmed once again and a pressure reduction is built up in the vacuum chamber  21 , and through actuation of the press ram  61  the meat which is situated in the shaping tube is moved further in the direction of advancement, i.e. into the calibrated shaping cavity again, etc. As soon as the entire amount of meat has been portioned and the press ram  49  which has moved forward in the shaping tube  55  has reached its lowermost position (which is no lower than the level of the bottom surface of the underside of the mating pressure plate  66  of the shaping tube body  53 ), a complete cutting operation is then carried out once again, so that the press ram can then be retracted from the shaping tube. 
     If different types of meat are to be processed or types of meat are to be portioned with different sizes and weights, it is possible to use differently dimensioned cutting and calibrating plates with differently dimensioned and shaped calibrated shaping cavities. With the same perforated cutter and the same shaping tube, the calibrating plates then differ through a different thickness, in order to vary the weight and size of the amount of meat to be portioned. However, if the size of the amount of meat to be portioned is to be varied in side view, it would then also be necessary to fit a different perforated cutter with correspondingly different sizes of cutting holes and a shaping tube of different cross section. 
     The calibrated cutting device which has been explained can be used to produce meat portions of equal size which differ, for example, by only extremely small amounts of +/−5 grams and less, for example of +/−2 grams. 
     The entire control arrangement may be of different structure. For example, an electrical control unit, for example in the form of a PLC, a contactor control unit or a relay control unit or in the form of combinations may be suitable. A microprocessor-assisted control unit is also possible, in particular if the calibrated cutting-device is incorporated into a larger installation. In the actual embodiment shown, compressed-air control has been described. Without being described in detail, it is possible for magnetic switches to be provided on the cylinders, working valves and control valves, and the valves used may be OR, AND, 3/2-way or, for example, 5/2 valves. Pressure reducers, manometers and vacuum switches are also components which can be used for operation. 
     For example, in particular the vacuum valve  27  described may also be actuated by plunger actuation from the displaceable cutter holder and the restoring air. 
     A very wide range of variants are possible for the vacuum-generating means explained in connection with the operation of the device. By way of example, it is possible for a vacuum-generating means to be based on the Venturi principle in order to generate a pressure reduction. In this case, the vacuum-generating means can be switched on by the pneumatic control unit only for the phases when the calibrating cavity is to be refilled with meat. However, it may also be necessary for this unit to be activated at all times, so that a “vacuum cushion” builds up in the filters, until the plunger valve  27  opens again. Naturally, it is also possible to use a continuously running vacuum pump. Reduced pressure is only passed into the vacuum or reduced-pressure plate by the valve plunger  27  which has been explained when this reduced pressure is required. In the interim periods, a vacuum cushion can build up in the filters. 
     With the calibrated cutting device it is possible, for example, to realize a cutting cycle time of 1 second, meaning that one slice of meat can be portioned and ejected every second.

Technology Classification (CPC): 1