METHOD AND APPARATUS FOR DOSING PARTICULATE MATERIAL

Abstract: A method and an apparatus for dosing pieces of meat and suchlike particulate material, wherein the material to be dosed is compacted in a dosing chamber (5), only thereafter excess material is removed and finally the material is removed from the dosing chamber.

Description: The invention relates to a method for dosing pieces of meat and similar deformable, particulate material by putting this material into a dosing chamber of predetermined capacity and being provided with an opening, removing excess material near that opening and thereafter removing that material from said dosing chamber. For putting this known method into practice, usually an apparatus comprising a rotatable table was used. In said table a plurality of openings are arranged, forming the upper openings of cylindrical dosing chambers arranged at the under side of the table. The bottom wall of the chamber is formed by a fixed bottom plate having one discharge opening. The bottom rims of the dosing chambers are slidingly movable on this plate when the table is rotating and each bottom opening is coming once every revolution into register with the discharge opening. Alternatively, the chambers are provided with bottom doors, which may be opened at the discharge station. For dosing different amounts of material, the capacity of the dosing chambers can be changed in a telescopic manner. The distance between the table and the bottom plate is to be adapted. During use of this known apparatus, the material to be dosed is put on the table, so that it will fall into the dosing chambers. Excess material is removed from the opening by a scraper blade or a rotary brush means. Subsequently, the dosing chamber which is filled up to its upper rim is emptied on passing across the discharge opening. The dosing accuracy of this method and the apparatus used therefor is limited if pieces of meat or similar deformable, particulate material are handled, since the filling rate of the dosing chambers in not constant. This is in particular true if the number of pieces required for filling each dosing chamber is relatively small, say under 15. One object of the invention is improving this accuracy. It is mentioned that US-A-2702405 discloses a molding method and apparatus for plastic material, for example for making hamburgers, having the features of the first parts of claims 1 and 6. The invention provides a method as set out in claim 1. Preferably, the compacting is done by filling the chamber while it has a capacity in excess of the predetermined capacity, subsequently reducing the capacity to the predetermined volume while an obstruction for material squeezed out of the chamber is arranged near to the opening. In a preferred embodiment, the opening of the dosing chamber is partly closed during the reduction of the capacity of the chamber. The extent of closure of said opening may be adapted to the kind of product to be dosed. This may easily be done by using a spring-loaded means. The spring load may be set to adapt the compression to the material to be dosed. Optimum results are obtained if the capacity of the chamber is reduced from the side opposite the opening and in particular in an upward direction. The invention also relates to an apparatus for dosing pieces of meat and similar deformable, particulate material as set out in claim 6. In a single and reliable embodiment of the apparatus of the invention, the dosing chamber is provided with a bottom which can be changed in height during the dosing. Very simply, the capacity may be changed in that the bottom is formed as a piston which is movable in a cylindrical dosing chamber. Suitably, the actuating means are adapted for cyclically displacing the piston such that the chamber has a capacity in excess of the predetermined one, thereafter a capacity equalling the predetermined one, then a capacity equal to zero and subsequently the excess capacity again. In this manner the material is reliably removed from the chamber and dosing errors due to sticky material are prevented. If the dosing chamber is rotatably mounted about an axis, a cam track can be arranged about the same axis, which disc forms part of the control means for displacing the piston in the dosing chamber. The usual dosing apparatuses as initially described may be modified to conform to the invention by providing an at least partly slanting surface forming the bottom of the dosing chamber, along which the under side of the dosing chamber is movable, which dosing chamber has a variable capacity in that it is telescopically extendable and retractable. By substituting a suitably curved bottom for the usual flat one, using telescopic dosing chambers and arranging means for partly closing the upper opening of the chamber, the disadvantage of the usual dosing apparatus can be removed. The invention will be explained in the following description of some embodiments which are schematically shown in the drawings. Fig. 1 shows a plan view of a preferred embodiment of the dosing apparatus according to the invention. Fig. 2 shows the apparatus of Fig. 1 in vertical cross-section. Fig. 3 shows a detail in section taken along the line III-III in Fig. 1. Fig. 4 shows a detail in section taken along the line IV-IV in Fig. 1. Fig. 5 shows a detail in section taken along the line V-V in Fig. 1. Fig. 6 shows a detail in section taken along the line VI-VI in Fig. 1. Fig. 7 is a partially developed view of a vertical section corresponding to Figures 3 to 6 through a second embodiment. In Figures 1 and 2 a preferred embodiment of the dosing apparatus according to the invention is shown in plan view and in vertical cross-section, respectively. A driven horizontal table 3 is rotatably arranged about an axle 2 which is supported in a frame 1. The table 3 is provided with a plurality of bores 4, forming the upper openings of cylindrical dosing chambers 5, which are all at the same distance from the axle. At the upper side of the table 3, several parts are arranged in the direction of rotation indicated by the arrow 6 subsequently; a feeding trough 7 for the product to be dosed; guiding plates 8 for forcing this product outwardly on the table; and oblong obstructing means 9 which is arranged close over the path of travel of the bores 4, which has a more or less pointed nose in the direction against the rotation and which is movable in a vertical direction against the settable load of a spring 10; a scraper blade 11 formed by a radially inwardly directed, fixed, vertical strip, the under rim of which is in close proximity to the table and a discharge device 12. Along the outer periphery of the table, a vertical strip 13 is arranged, preventing the material to be dosed from falling off the table. The apparatus is used as follows: Material to be dosed is fed through the trough 7 onto the table 3 and forced towards the bors 4 by the guiding plates 8, so that it will fall into the chambers during the rotation of the table. The material should be in excess. First the situation as shown in Fig. 3 is met: A piston 14, which is movable in the dosing chamber 5, is kept in its lowermost position by a follower 16, running in a curve track 15 which is static and arranged around the axle 2. After movement of the table to the position as shown in Fig. 4, the material in the chamber is exposed to a gradually increasing pressure by the upwardly moving piston 14 and the obstructing means 9 which is now over the opening of the chamber. The piston 14 is moved upwardly by the height increase of the curve track 15 until the dosing chamber has the predetermined capacity. Any excess material can be expressed alongside and underneath the obstructing means owing to the fact that it is only partly closing the opening and the spring loaded arrangement if applicable. Further movement does not change the position of the piston in the chamber. The bore 4 passes underneath the scraper blade 11, removing any excess material, so that the correct amount of material is separated in the chamber, as shown in Fig. 5. This amount of material is removed from the chamber by moving the piston 14 to a position such that its upper surface is flush with the upper surface of the table 3, as shown in Fig. 6. This material is removed by a discharge means 12, comprising a horizontal disc 17 having cylindrical bores 18, which is lying against the table and is rotatable in a direction shown with the arrow 19. The separated amounts of material are separately expressed into subsequent bores 18 and removed, for instance to be dispensed into separate containers which are moving along. Another embodiment is shown in Fig. 7. The table 3 is provided with bores 4 again and cylindrical dosing chambers are arranged underneath these bores. The chambers each are formed by two telescopically movable parts 21, 22, the wider and lower part 22 being urged downwardly by a spring 23 towards a bottom part 24. The seal between the lower part 22 and the bottom plate 24 being provided by a ring 26, which is pivotably connected to the lower part 22 by means of an axle extending in a radial direction with respect to the axis of rotation of the table 3. The bottom plate 24 forms the bottom of the dosing chambers and shows in principle in a circumferential direction about the axle 2 a similar profile as the curve track 15 of the previous embodiment, so that the dosing chambers are changing their capacity in a similar manner. Compacting and removal of excess are effected in a manner as disclosed in connection with the previous embodiment. Discharging the separated material is effected differently in that the higher portion of the curve track 15 cannot be translated in a higher portion of the bottom plate 24. For discharging this material the bottom plate is provided with a discharge opening 25 through which the material is allowed to fall into suitable containers passing along, if required assisted by a jet of pressurized air.

Claims: A method for dosing pieces of meat or similar deformable, particulate material by the steps of (i) by putting this material into a chamber (5) having an opening (4), (ii) thereafter compacting the material in the chamber and removing excess material near said opening (4) and (iii) thereafter discharging said material from the chamber, characterized in that the material in the chamber (5) is compacted by reducing the chamber's capacity prior to the removing of excess material near the chamber opening (4). A method according to claim 1 wherein the material is compacted by filling the chamber (5) while it has a capacity in excess of the desired volume of the dose, and subsequently reducing its capacity to the desired volume while an obstruction (9) hinders squeezing of material out of the chamber at the opening (4). A method according to claim 2, wherein the opening is partly closed by said obstruction (9) during the reduction of the capacity of the chamber. A method according to claim 2 or claim 3 wherein the capacity of the chamber is reduced by moving a wall (14,24) at the side opposite to the opening. A method according to any one of claims 2 to 4, wherein the capacity of the chamber is reduced in upward direction. Dosing apparatus for pieces of meat and similar deformable, particulate material, comprising at least one dosing chamber (5) which has at least an opening (4) at its upper side and is closed or is selectively closable at its bottom side, filling means for putting material to be dosed into the chamber, and means (11) for removing excess material near said opening (4) of the chamber, and said dosing chamber having a wall (14,24) movable so that its capacity is variable and actuating means (15) being provided for moving said movable wall relative to the chamber to effect such variation of capacity, means (9) for hindering escape of the material at said opening when said relative movement of said movable wall reducing capacity of the chamber occurs, and means for removing the material from the chamber, characterized in that said actuating means is arranged to cause relative movement of said wall (14,24) so as to effect reduction of the capacity of the chamber after filling by said filling means and prior to operation of said means (11) for removing excess material. Posing apparatus of claim 6 wherein the dosing chamber (5) is of cylindrical shape and that said movable wall is opposite the opening (4) and forms part of a piston (14) which is movable in the chamber by said actuating means. Dosing apparatus of claim 7, wherein the actuating means is adapted for cyclically displacing the piston (14) such that the chamber has a capacity in excess of the desired dosing volume thereafter a capacity equalling the desired dosing volume, then a capacity equal to zero and subsequently said excess capacity again. Dosing apparatus of claim 7 or claim 8 wherein the dosing chamber (5) is rotatably arranged about an axis (2), there being a cam track (15) about the same axis forming part of the actuating means for displacing the piston (14) in the dosing chamber (5).

Inventors: KLEINTJENS, HENDRIK JOZEF
Applicants: UNILEVER N.V., UNILEVER PLC
Application year: 1986
Main classification: A22C7
IPC codes: A22C7