Abstract:
The invention relates to a method and a device for shaping and portioning a soft, pasty product within a tubular casing made of foil material, the encased product being supplied to a shaping and portioning station. The product leaves said shaping and portioning station divided into portions. The invention further comprises a metering station arranged directly upstream of the shaping and portioning station. The metering station meters the quantity of the product supplied to shaping and portioning station per unit of time.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a method and a device for shaping and portioning a soft, pasty product within a tubular casing of foil material according to the preamble of the independent claims. 
     2. Description of Relevant Art 
     Methods and devices of this type are known, for example, in the field of foodstuffs technology for portioning cheese into slice-like, plate-shaped form. DE 195 01 106 A1 of the same Applicants discloses a method of this type and the associated device. In this case, the product provided with a casing is shaped between two shaping elements, which are preferably constructed as circulating belts with webs, and is portioned into individual slices. However, in this case the product is portioned in a cold, relatively solid state. 
     A shaping device for packing a soft product is known from DE 38 41 945 A1, in which the encased product is also guided between two belts provided with clamping members, and is thereby provided with its intended shape. Since the product is processed in a relatively fluid state in this case, it is difficult to obtain a specific weight for each slice of cheese. Consequently, the belts which face one another extend in this case between two parallel, smooth plates, whose distance from one another is variable. In this manner, it is possible to vary the volume of the portions formed in the casing between successive clamping members. However, a disadvantage in this case is the relatively complex construction, since it is necessary to provide the adjustable plate arrangement within the circulating belt drives. The belts slide continuously along the plates, so that a high degree of belt wear has to be taken into account. 
     It is therefore the object of the present invention to propose a method and a device for shaping and portioning a soft, pasty product, in which the quantity or the volume of the product supplied to the shaping and portioning station can be adjusted at any time. 
     SUMMARY OF THE INVENTION 
     This object is attained according to the invention by the features disclosed in the characterizing part of the independent claims. In particular, in one aspect of the invention, a method for shaping and portioning a soft, pasty product within a tubular casing is disclosed. The method includes the steps of passing a product encased within a tubular casing through a metering station, metering a quantity of the product per unit of time, supplying the metered product to a shaping and portioning station, and portioning the metered product into portions in the shaping and portioning station. 
     In another aspect of the invention, a device for shaping and portioning a soft, pasty product within a tubular casino made of a foil material includes a shaping and portioning station, to which the encased product is supplied. The encased product leaves the shaping and portioning station in divided portions. A metering station is arranged directly upstream of the shaping and portioning station, in order to meter a quantity of the product supplied to the shaping and portioning station per unit of time. 
     Advantageous embodiments and further developments of the invention form the subject matter of the dependent claims. 
     In order to meter the quantity or volume of the encased product supplied to the shaping and portioning station, a metering station is provided according to the invention, which is arranged upstream of the product advance immediately prior to the shaping and portioning station. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 depicts a side view of one embodiment of the metering device of the present invention in operational context with product advance and the shaping and portioning station. 
     FIG. 2 depicts an enlarged downward horizontal cross-sectional view of the metering device depicted in FIG. 1 taken at “A” of FIG.  1 . 
     FIG. 3 is a schematic diagram of the metering device of the invention portrayed from the side opposite that shown in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The metering station is advantageously formed by two rotatable rollers, which are arranged axially parallel at a reciprocal distance apart and between which the encased product which is to be metered is guided. 
     By way of a simple variation in the reciprocal distance of the two rollers, it is possible to vary the thickness and therefore the quantity or volume of the product passing through. Advantageously, only one roller is adjustably constructed. In a preferred embodiment, the axle of one roller is mounted on an eccentric to the axis of rotation of the roller so that the roller per se is linearly adjustable relative to the other roller. 
     The rollers rotate in opposite directions and can be free-running, i.e., not driven. In this case, the rollers are carried along or driven by the friction between the product casing and the roller surface. However, both rollers are preferably driven in opposite directions, the drive being effected at the same velocity as the belt drive of the shaping and portioning station. 
     The rollers are preferably mounted at one end and are made of stainless steel or another material which meets the hygiene requirements in foodstuffs technology. 
     The metering station is preferably capable of adjustment of automatic adjustment of the distance between the rollers, and hence the rate of product flow per unit time, in response to the density of the product passing through the metering station. In one preferred embodiment, the distance between the rollers is adjusted to maintain the individually wrapped slices at a preset weight. In one embodiment, the distance between the rollers is automatically adjusted in response to an automatic weighing device which weighs one or more individually wrapped slices produced after the foil tube passes through a shaping and portioning station, a heat sealing station and a station that cuts the heat sealed portions into individually wrapped slices, adjusting for increased space between the rollers when the slices are under a preset weight and adjusting for decreased space between the rollers when the slices are over a preset weight. 
     The maximum and minimum distance between the rollers may be selected among any which is found suitable for a particular end use application. In one embodiment, the the maximum distance between the rollers is less than 3 mm, more preferably less than 2.2 mm, and the preferred minimum distance between the rollers is less than 0.5 mm, more preferably about twice the thickness of the foil used to make the foil tube. This latter embodiment is particularly useful for interrupting production of individually wrapped slices whereby the opening between the rollers is reduced prior to stopping production to prevent unmetered pasty product from flowing down the foil tube past the metering station during the interruption. The opening is then widened to the desired slice thickness after production is restarted. 
     The invention will be explained in further detail by way of an embodiment with the aid of FIGS. 1 to  3 . As used below, the term “bearings” means components for permitting rotation of a shaft or axle about its axis with reduced friction, such as ball bearings and sleeve bearings. 
     The device for shaping and portioning is part of a device for packing a soft, pasty product in a casing of foil material, preferably plastics material foil. The flat plastics material foil is withdrawn from a supply roll and supplied to a device which forms a foil tubing from the flat foil (not shown in the drawing). The foil tubing  4  is guided along a shaping tube  2  and welded by a longitudinal seam station with the aid of a heating element  1 . Extending within the shaping tube  2  is a filling pipe  3 , through which the soft, pasty product is introduced into the foil tubing  4 . An example of a device which is capable of these functions is provided by U.S. Pat. No. 5,222,346, which is incorporated herein by reference. 
     The foil tubing  4 , which contains the product which is to be shaped, then passes to the metering station  5 . 
     The metering station  5  comprises a frame  5   a , which has mounted within it two (first and second) rollers  6 ,  7 , which are rotatable about their axles  15 ,  16  and are arranged at a distance from one another. The foil tubing  4  is introduced into the space between the rollers, so that the foil tubing  4  and the product contained therein is compressed to a thickness corresponding to the distance between the rollers  6 ,  7  and leaves the metering station  5  in this form. By means of the rollers  6 ,  7 , a metering of the quantity of the product passing through the metering station per unit of time is therefore effected. 
     The rollers  6 ,  7  rotate in opposite directions and can be free-running, i.e., not driven. In this case, they are set in rotation by the friction of the product-filled foil tubing  4  passing through the rollers. In an advantageous embodiment, the two rollers  6 ,  7  are driven in opposite directions and are driven at the velocity of the foil passing through them, such as by drive linkage(s) connected to the rotating elements of the shaping and portioning station. 
     At least one of the rollers is adjustably constructed, so that the distance between the rollers and therefore also the thickness of the product disposed in the foil tubing can be adjusted. In this respect, the adjustment of the roller  7 , for example, is effected in the direction of the arrow  8  as shown by the dashed lined near the outer circumference of roller  7  in FIG. 1 (indicating a new position occupied by roller  7  when the space between the rollers is increased). 
     The flattened foil tubing  4  leaving the metering station  5  and containing the product subsequently enters the shaping and portioning station  9 , which in the example is formed by two continuous belts  10 ,  11 , to which cleats  12 ,  13  are secured in each case. The encased, flattened, metered product now passes between the continuous belts  10 ,  11 , the cleats  12 ,  13  being forced together with the constant rotation of the continuous belts  10 ,  11 , so that the product is displaced in the region of the cleats  12 ,  13  which are forced together and is divided into portions  14 , which leave the shaping and portioning unit. 
     In the region between the portions  14 , the foil tubing is then welded in a suitable device, resulting in portions  14  which are hermetically sealed relative to one another (not shown in the drawing). Following the welding, the portions can be cut into individually wrapped slices. An example of a device capable of carrying out these functions is provided by U.S. Pat. No. 5,222,346, which is already incorporated herein by reference. 
     FIG. 2 depicts an enlarged downward horizontal cross-sectional view of the metering device depicted in FIG. 1 taken at “A” of FIG.  1 . Reference numerals in FIG. 2 corresponding to those in FIG. 1 refer to the same parts as in FIG.  1 . As can be seen in FIG. 2, axle  15  is fixedly connected to roller  7  at one end at a location coinciding with the axis of rotation of roller  7 . Axle  15  is also fixedly connected to a first hollow shaft  18  at the end opposite the end connected to roller  7 . The first hollow shaft  18  is fixedly connected to pully  17  (which is connected to a drive, not shown) and rotates within an eccentric rotatable hollow shaft  26  via circular bearing races  19  and  20 , containing bearings, located proximate to the distal ends of hollow shaft  18 . 
     Axle  16  is fixedly connected to roller  6  on one end at a location coinciding with the axis of rotation of roller  6 . Axle  16  is also fixedly connected to a second hollow shaft  22  at the end opposite to that connected to roller  6 . The second hollow shaft  22  is fixedly connected to pully  21  (which is connected to a drive, not shown). The second hollow shaft  22  rotates within frame  5   a  via circular bearing races  23  and  24 , also containing bearings, and also located proximate to the distal ends of shaft  22 . 
     Eccentric rotatable hollow shaft  26  has a cylidrically shaped inner surface  26   a  adapted for accepting the rotatable hollow shaft  18  and is rotatably mounted within frame  5   a  via circular bearing races  27  and  29 , each containing bearings, located proximate to the distal ends of the rotatable hollow shaft  26 . The circular bearing races  27  and  29  are off-center from the axis of rotation of axle  15  in the same direction so that the eccentric rotatable hollow shaft  26  has an axis of rotation parallel to, but off-center from, the axis of rotation of the rollers. When eccentric rotatable shaft  26  is rotated, the distance between the rollers, and therefore also the thickness of the product disposed in the foil tubing, can be adjusted as shown in FIG.  1 . 
     The degree of offset, and hence the maximum and minimum distance between rollers  6 , 7 , may be selected among any which is found suitable for a particular end use application. In one embodiment, the degree of offset (i.e., the distance between the axis of rotation of axle  15  and the axis of rotation of eccentric rotatable hollow shaft  26 ) is selected so that the maximum distance between rollers  6 , 7  is less than 3 mm. In a preferred embodiment, the degree of offset is selected so that the minimum distance between rollers  6 , 7  is less than 0.5 mm, more preferably about twice the thickness of the foil used to make the foil tube. 
     In this preferred embodiment, eccentric rotatable hollow shaft  26  is fixedly connected to pully  25 , which is connected via a chain or belt to a servo-motor (not shown). A distance measuring device  30  having a probe  30   a  is preferably in substantial alignment with directional vector arrow  8  in FIG.  1 . The distance measuring device preferably is capable of adjustment of its probe  30   a  toward and away from the eccentric rotatable hollow shaft  26  by coming in contact with contact surface  30   b , which is a circular surface concentric with the axis of rotation of eccentric rotatable hollow shaft  26 , and is capable of providing a signal to the servo-motor to rotate the eccentric rotatable hollow shaft  26  in a direction which maintains the distance set via the distance measuring device. In a particularly preferred embodiment, the distance measuring device is adapted to receive a signal from an automatic weighing device which weighs one or more individually wrapped slices produced after the foil tube passes through a shaping and portioning station, a heat sealing station and a station that cuts the heat sealed portions into individually wrapped slices and adjust for increased space between rollers  6 , 7  when the slices are under a preset weight and adjust for decreased space between rollers  6 , 7  when the slices are over a preset weight. 
     FIG. 3 is a schematic diagram showing the metering station  5  from the side opposite to that shown in FIG.  1 . Pulleys  17  and  21  are driven via belts  34  and  35 , respectively, by pulleys  36  and  37 , respectively, which are fixedly connected to drive rollers  40  and  41 , respectively, for driving belts  10  and  11 , respectively, of shaping and portioning station  9  (shown in FIG.  1 ). Pully  25  for eccentric rotatable hollow shaft  26  is connected via belt  33  to servo-motor  31 . Servo-motor  31  is connected via electrical connection  32  to distance measuring device  30  which is also connected via connection  38  to weighing device  39 . Signals from weighing device  39  adjust the distance of distance measuring device probe  30   a  from contact surface  30   b  and signals from probe  30   a  signal the servo-motor to turn pulley  25  to increase or decrease the distance between the rollers as required. 
     A significant advantage of the invention is that a precise quantity metering of the product supplied to the shaping and portioning station  9 , which can be easily varied at any time, is possible by way of a simply constructed metering station  5  at the entrance to the shaping and portioning station  9 . When the metering is based on weight of one or more individually wrapped slices, the invention is able to accurately maintain a preset weight despite variations in the density of the pasty product as it is introduced into the foil tube. 
     Thus, portions of a constant quantity and packing quality can be produced in a simple manner. A quantity metering prior to portioning is particularly necessary in the case of products which are very fluid, in order to attain a clean shaping of the product. 
     Legend to Drawing 
       1  longitudinal seam station 
       2  shaping tube 
       3  filling tube 
       4  foil tubing 
       5  metering station 
       5   a  metering station frame 
       6  first roller 
       7  second roller 
       8  arrow showing direction of roller  7  adjustment 
       9  shaping and portioning station 
       10  first continuous belt 
       11  second continuous belt 
       12  cleat 
       13  cleat 
       14  portion 
       15  first axle 
       16  second axle 
       17  first pulley 
       18  first rotatable hollow shaft 
       19  first race of bearings for first shaft 
       20  second race of bearings for first shaft 
       21  second pulley 
       22  second rotatable hollow shaft 
       23  first race of bearings for second shaft 
       24  second race of bearings for second shaft 
       25  pulley for eccentric shaft 
       26  eccentric shaft 
       26   a  cylindrical inner surface 
       27  first bearing race for eccentric shaft 
       28  [RESERVED] 
       29  second bearing race for eccentric shaft 
       30  distance measuring device 
       30   a  distance measuring device probe 
       30   b  contact surface for probe 
       31  servo-motor 
       32  connecting leads 
       33  eccentric shaft pulley belt 
       34  first pulley belt 
       35  second pulley belt 
       36  first shaping and portioning station pulley 
       37  second shaping and portioning station pulley 
       38  connecting control lead 
       39  weighing device 
       40  first drive roller for belt  10   
       41  second drive roller for belt  11