WO1992000665A1

WO1992000665A1 - A cheese-making tank

Info

Publication number: WO1992000665A1
Application number: PCT/DK1991/000191
Authority: WO
Inventors: Per Grostøl NIELSEN
Original assignee: Apv Pasilac A/S
Priority date: 1990-07-10
Filing date: 1991-07-04
Publication date: 1992-01-23
Also published as: DK166690D0; DK166690A

Abstract

A cheese-making tank comprises a frame (4) rotatably journalled about a vertical axis. The frame comprises two sets of stirring and cutting means (6, 9) adapted to cut a cheese mass during the rotation of the frame (4) in a first direction and to stir said cheese mass when said frame is rotating in a second direction. The lower set of stirring and cutting means (9) comprises a plurality of plate-shaped bodies (10), each body being pivotally arranged and adapted to pivot between a cutting position, in which the bodies are substantially parallel to the direction of rotation (8), and a stirring position in which said bodies are substantially transverse to said direction of rotation. The plate-shaped bodies (10) are rotatably journalled about their respective axis, where the axes extend substantially in their respective plane parallel to the rotary shaft (2) of the frame. The axes of rotation of the bodies (10) extend substantially parallel to one another and incline from the top and downwards in a rearward direction relative to the first direction of rotation (8) of the frame (4).

Description

Title: A Cheese-Making Tank

Technical Field

The invention relates to a cheese-making tank comprising a container receiving a cheese mass, where the container comprises at least one frame rotatably journalled about a vertical axis and carrying a first upper and a second lower set of stirring and cutting means, which are adapted to cut the cheese mass while the frame is being rotated in a first direction and to stir said cheese mass while the frame is being rotated in a second direction, and where the second lower set of stirring and cutting means includes a plurality of plate-shaped bodies, each plate-shaped body being pivotally arranged and adapted to pivot between a cutting position, in which it is substantially parallel to the direction of rotation, and a stirring position, in which it is substantially transverse to said direction of rotation.

Background Art

The known cheese-making tanks of the above type are filled with milk which is caused to curdle by means of enzyme and acid, acid alone or a complex coagulant. The curd is subsequently cut into small pieces, preferably small cubes, by the frame being caused to rotate in the first direction of rotation with the result that the whey can be easily separated from the cheese mass and drained off. After the cutting, the curd is subjected to a heating and a simul¬ taneous stirring by the frame being caused to rotate in the second direction of rotation. As a result additional whey is separated from the cheese mass, whereby the cheese mass simultaneously becomes more solid. The cutting re¬ sults from the sharp edges of the stirring and cutting means of the frame, said edges turning in the moving direction of the frame when said frame is moving into the first direction of rotation. At the same time, the plate- shaped bodies of the lower stirring and cutting means are turned into such a position that they follow the relative flow direction of the curd with the result that their usually sharpened front edges face the moving direction. During the stirring, where the frame is rotated in the second direction of rotation, rounded edges on the first upper set of stirring and cutting means are carried through the cheese mass without cutting therein. At the same time, the plate-shaped bodies of the lower set of stirring and cutting means rotate about their axis of rotation in such a manner that they are positioned in an angle relative to the bottom and thereby assist in stirring the curd.

It is important for the structure of the end product that the curd cubes are as uniform as possible and that they are not destroyed to such an extent that curd particles arise and are lost in the whey. The known stuctures are encumbered with the drawback that the plate-shaped bodies present a certain resistance even in the cutting direction with the result that some of the curd has been crushed into so small particles that they are drained off with the whey and are thereby lost.

Disclosure of the Invention

The cheese-making tank according to the present invention is characterised in that the plate-shaped bodies are pivotally arranged about their respective axis, said axes extending substantially on their respective plane parallel to the axis of rotation of the frame, where the axes of rotation of the bodies are substantially parallel to one another and inclining from the top and downwards in a rearward direction relative to the first direction of rotation of the frame.

As a result a cheese-making tank is provided in which the whey is efficiently and uniformly cut even in the portion adjacent the bottom of the container, and in which it is possible at the same time to carry out an efficient stir¬ ring while maintaining a relatively low production of curd particles being lost in the whey. The latter is especially due to the fact that the plate-shaped bodies can be shaped relatively small and light with the result that they allow a cutting of the cheese from the bottom and upwards to the portion in which the upper set of stirring and cutting means operate. In addition, the plate- shaped bodies provide a relatively large area for an effi¬ cient stirring, the inclining of said plate-shaped bodies during the stirring process causing the cheese mass to move in a secure, but nevertheless lenient manner upwards along the surfaces of said bodies and outwards through the space between the upper and the lower set of stirring and cutting means without lumps of the curd tending to stick therebetween. The cutting can be carried out at a relatively slow speed of rotation because the plate-shaped bodies can be of a relatively short radial length, i.e. in a direction away from their axis of rotation, without having an effect on the total surface applying during the stirring process. As the plate-shaped bodies are of a relatively short radial length in a direction away from their axis of rotation, they can enter their position parallel to the flow direction during the cutting process even at a relatively low speed of rotation. The total available area during the stirring process is ensured by means of a suitably high number of plate-shaped bodies.

According to the invention it is particularly advantageous when the plate-shaped bodies are carried by two parallel, horizontal bars permanently fixed to the frame.

According to the invention the bars may extend through their respective opening in each plate-shaped body, where the plate-shaped bodies are hinged to the bars by means of shafts, said shafts extending through through holes in the bars from diametrically opposite sides of each opening. As a result, a particularly simple embodiment of the invention is obtained by means of relatively few parts .

According to the invention, the plate-shaped bodies may be provided with recesses adjacent the openings, said recesses receiving the bars in such a manner that the bodies in the stirring position are arranged on substan- tially the same plane as the bars, whereby the stirring is particularly efficient.

In addition according to the invention each plate-shaped body may advantageously be hinged to the bars by means of a plate-shaped member permanently fixed on said bars, said plate-shaped member extending substantially perpen¬ dicular to the bars and comprising a sharpened edge in the cutting direction.

According to the invention, each plate-shaped body may be hinged to the associated member permanently fixed on the bars by means of U-shaped legs, said legs extending through their respective opening in the pivotal plate-shaped body, and stopping means may be provided to stop the movement of the plate-shaped bodies towards the cutting position in such a manner that said plate-shaped bodies are automat- ically returned to the stirring position when the direction of rotation of the frame is reversed. In this manner a particularly simple mounting of the plate-shaped bodies is obtained, and by a suitable shaping of the U-shaped legs in the stirring position said bodies can automatically abut the rear edge of the permanent, plate-shaped bodies.

According to the invention it is particularly advantageous when the plate-shaped bodies overlap one another in the stirring position. Finally according to the invention the plate-shaped bodies may be made of a plastic material, such as polyethylene or polypropylene. In this manner it is ensured by a suit¬ able selection of plastic material that the plate-shaped bodies are of such a low gravity that they automatically enter the cutting position before the cutting is initiated, whereby a particularly lenient treatment of the curd is ensured.

Brief Description of the Drawing

The invention is described in greater detail below with reference to the accompanying drawing, in which

Fig. 1 is a diagrammatic top view of a cheese-making tank according to the invention,

Fig. 2 is a perspective view during a cutting movement of a preferred embodiment of a rotatably journalled frame with stirring and cutting means to be used inside the cheese-making tank of Fig. 1,

Fig. 3 corresponds to Fig. 2, but during a stirring move¬ ment ,

Fig. 4 on a larger scale a perspective view of a plate- shaped body to be used in the frame of Figs. 2 and 3,

Fig. 5 on a larger scale a rear view of the top portion of the plate-shaped body of Fig. 4,

Fig. 6 a perspective view of a second embodiment of a cutting frame according to the invention to be used in the cheese-making tank of Fig. 1 and seen in the cutting position, whereby parts have been omitted for the sake of clarity, Fig. 7 corresponds to Fig. 6, but in the stirring position, and

Fig. 8 on a larger scale a perspective view of a portion of the frame of Figs. 6 and 7.

Best Mode for Carrying Out the Invention.

The cheese-making tank of Fig. 1 comprises a container indicated by means of dotted lines and designated the general reference numeral 1. When seen from the top, the container is of a cross section almost corresponding to the figure of eight. The container comprises two halves, and a vertical shaft 2 and 3 is rotatably journalled at the centre of each half, said shafts carrying their respec¬ tive frame 4 and 5 caused to rotate in a conventionally known manner by means of driving means not shown.

Figs. 2 and 3 illustrate an embodiment of such a frame. The frame 4 comprises a first upper set of stirring and cutting means 6 in turn comprising a plurality of verti¬ cally extending plate-shaped knives 7. The plate-shaped knives are provided with sharp edges facing in the direc- tion of rotation of the frame 4 during the cutting process, i.e. in the direction indicated by an arrow 8 in Fig. 2. A second lower set of stirring and cutting means 9 is pro¬ vided at the bottom of the frame immediately above the bot¬ tom of the container 1. The second lower set of stirring and cutting means comprises a plurality of plates 10 pivot¬ ally arranged on two horizontal bars 11 and 12 arranged in parallel and permanently fixed in the frame 4. As shown in Figs. 4 and 5, the plates 10 are substantially rectangular and comprise a through opening 13 and 14 at the upper and lower end immediately adjacent one longitudinal edge. The through openings allow passage of the bars 11 and 12. A groove 15, 16 and 17, 18, respectively, is pressed out to both sides of the openings 13 and 14, where the groove 15, 16 to one side of said openings 13 and 14, respective¬ ly, is directed to one side of the plate 10, cf. Fig. 4, whereas the groove 17, 18 to the opposite side of the openings 13 and 14, respectively, is directed to the opposite side of the plate 10. As a result, the plate 10 is capable of pivoting between a position transverse to the bars 11 and 12 and a position in which they abut said bars 11 and 12 while said bars are received in the grooves 15, 17 and 16, 18, respectively, cf. the situation indicat¬ ed in Fig. 5 where the bar 11 is indicated by means of a dotted line.

A rotary shaft 19, 20 is welded in the centre of the openings 13 and 14, said shafts extending diametrically through a mating through hole 21, cf. Fig. 5, in the bars

11 and 12. The rotary shafts 19, 20 in each plate are shaped coaxially with one another and extend substantially parallel to and adjacent a first longitudinal edge 22. Like the adjacent edge 23 positioned at the top after the mounting, the longitudinal edge 22 has been sharpened in such a manner that the plate 10 can operate as a knife after the mounting.

The particular embodiment of the plate 10 ensures that it is capable of turning approximately 90° about the common axis of the rotary shafts 19, 20. The bottom of the grooves 15, 16, 17, and 18 presents a limit to the pivoting move¬ ment of the plate in one direction of rotation. The plate parts adjacent the openings 13, 14 forming the adjacent edges of the grooves 15, 16, 17, and 18 present a limit to the pivoting movement of said plates in the opposite direction about the rotary shafts 19, 20.

As illustrated in Figs. 2 and 3, the parallel bars 11 and

12 are staggered relative to the plane of the frame 4 in such a manner that the lower bar 12 is positioned at a distance in the rearward direction relative to the cutting direction 8 of said frame with the result that the axis of rotation of the plates 10 in this moving direction 8 extend obliquely from the top and downwards in a rearward direction. As a result, the sharp edges of the plates 10 face forwards in the cutting direction when the plates 10 are positioned transverse to the bars 11, 12. In use, the latter occurs automatically because when the frame 4 is caused to rotate about the vertical shaft 20 in the cutting direction 8, the plates 10 enter a position transverse to the bars 11 and 12 following the flow direction of the cheese mass relative to the frame.

When the direction of rotation of the frame 4 is reversed such that it follows the direction indicated by an arrow 24 in Fig. 3, the plates 10 are pressed downwards towards the bars and form a continuous stirring surface, which by means of a suitable number of plates can cover the entire area along the bottom of the container between the rotary shaft 2 of the frame 4 and the outermost end of said frame when seen in horizontal direction. All the plates 10 of Figs. 2 and 3 are adapted to be pivoted down to the same side of the bars 11 and 12, but in order to cover the area between the shaft 2 and the outermost end of the frame 4 completely when seen in radial direction, one or more of the plates can also be adapted to be pivoted down to the other side about their rotary shaft. A suitable shaping of the rims of the plates 10 adjacent the openings 13, 14 ensures that the plates 10 enter a position trans¬ verse to the bars 11, 12 during the cutting process in such a manner that said plates 10 are easily and quickly pivoted down into the stirring position where they abut the bars 11, 12 when the direction of rotation of the frame is reversed.

The illustrated embodiment of the plate 10 is preferably made of a suitable metal material, In which the grooves 15 to 18 are easily produced by pressing, and in which the shafts l j^' , 20 are relatively easily welded in a correct position during the mounting of the plates 10 on the bars 11, 12. However, by producing the plates 10 of a plastic material, such as polyethylene or polypropylene both having a density lower than the density of milk, the plates 10 automatically enter a position transverse to the bars 11, 12 in the cutting position before the cutting is initiated, which results in a very lenient treatment of the curd. Figs. 6 to 8 illustrate a second embodiment of a lower set of stirring and cutting means 9. The stirring and cutting means of this embodiment comprise a plurality of plate-shaped knives 25 permanently mounted parallel to the cutting direction on bars 11, 12 corresponding to the bars used in the embodiment of Figs. 2 to 5. The permanently fixed knives 25 comprise sharpened front and upper edges 26 and 27, respectively, cf. Fig. 8. Plates 31 are mounted at the rearmost rim of the knives 25 by means of U-shaped welded legs 28, 29 and 30. Each plate 31 comprises openings 32, 33 and 34 receiving the legs 28, 29, and 30 and is adapted to pivot between a position substantially on a plane with the associated knife 25, cf. Fig. 6, and a position substantially perpendicular to said knives 25, cf. Fig. 7. A suitable shaping of the legs 28, 29, and 30 and a suitable dimensioning of the plates 31 ensure that said plates 31 abut the adjacent edge of the associated knife 25 in the position perpendicular to said knives 25 as well as the edge of the adjacent plate 31. The latter position is additionally ensured by shaping the plates 31 with recesses 35, 36, and 37 in such a manner that each plate 31 clears the legs 28, 29, and 30 of the adjacent plate 31. As indicated in Figs. 6 and 7, a stopping means 38, 39, and 40, respectively, is mounted at the free ends of the legs 28, 29, and 30. The stopping means are adapted to stop the movement of the plates 31 into the position on plane with the fixed knife 25. The stopping means 28, 29, and 30 can for instance be nuts screwed on the legs 28, 29, and 30 by way of threads.

According to the described cheese-making tank, the lower stirring and cutting means ensure during the cutting process, i.e. during the movement of the frame 4 in the direction indicated by an arrow 8, that the curd is effi¬ ciently and leniently cut in the area between the bottom of the container 1 and the area of the upper set of stir¬ ring and cutting means 6. During the latter movement, the plate-shaped bodies automatically enter a position in the cutting direction. By reversing the direction of rotation of the frame 4 to the direction indicated by an arrow 24, the plates 10, 31 automatically position themselves cor¬ rectly in the stirring position while filling out the entire area between the rotary shaft 2 of the frame 4 and the radially outermost end thereof. In this manner an efficient stirring of the curd is ensured at the same time as the inclining of said plates relative to the moving direction ensures that said stirring is performed without causing lumps of the curd to get stuck.

The above position of the plates 10, 31 ensures that their lower rims can be shaped in such a manner that during the stirring process they can follow the bottom of the con¬ tainer with the effect that an additional security is achieved that lumps of curd do not stick between said plates 10, 31 and the bottom of the container.

The plates 31 of the embodiment of Figs. 6, 7, and 8 are preferably also made of a plastic material with the result that already before the cutting is initiated, said plates automatically enter a position in the desired position.

The invention has been described with reference to pre¬ ferred embodiments. Many modifications may, however, be carried out without thereby deviating from the scope of the invention.

Claims

Cl aims .

1. A cheese-making tank comprising a container receiving a cheese mass, where the container comprises at least one frame rotatably journalled about a vertical axis and carrying a first upper and a second lower set of stirring and cutting means, which are adapted to cut the cheese mass while the frame is being rotated in a first direction and to stir said cheese mass while the frame is being ro¬ tated in a second direction, and where the second lower set of stirring and cutting means includes a plurality of plate-shaped bodies, each plate-shaped body being pivotally arranged and adapted to pivot between a cutting position, in which it is substantially parallel to the direction of rotation, and a stirring position, in which it is substan- tially transverse to said direction of rotation, c h a r¬ a c t e r i s e d in that the plate-shaped bodies (10, 31) are pivotally arranged about their respective axis, said axes extending substantially on their respective plane parallel to the axis of rotation of the frame, where the axes of rotation of the bodies (10, 31) are substan¬ tially parallel to one another and inclining from the top and downwards in a rearward direction relative to the first direction of rotation (8) of the frame.

2. A cheese-making tank as claimed in claim 1, c h a r- c t e r i s e d in that the plate-shaped bodies (10,

31) are carried by two horizontal bars (11, 12) extending in parallel and being permanently fixed to the frame (4) .

3. A cheese-making tank as claimed in claim 2, c h a r¬ a c t e r i s e d in that the bars (11, 12) extend through their respective opening (13, 14) in each plate-shaped body (10) , where the plate-shaped bodies are hinged to the bars (11, 12) by means of shafts (19, 20), said shafts extending through through holes (21) in the bars (11, 12) from diametrically opposite sides of each opening (13, 14).

4. A cheese-making tank as claimed in claim 3, c h a r¬ a c t e r i s e d in that the plate-shaped bodies (10) are provided with recesses (15, 16, 17 and 18) adjacent

5 the openings (13, 14) , said recesses receiving the bars

(11, 12) in such a manner that the bodies (10) in the stirring position are arranged on substantially the same plane as the bars (11, 12).

5. A cheese-making tank as claimed in claim 2, c h a r- lO a c t e r i s e d in that each plate-shaped body (31) is hinged to the bars (11, 12) by means of a plate-shaped member (25) permanently fixed on said bars (11, 12) , said plate-shaped member extending substantially perpendicular to the bars (11, 12) and comprising a sharpened edge (26, 15 27) in the cutting direction.

6. A cheese-making tank as claimed in claim 5, c h a r¬ a c t e r i s e d in that each plate-shaped body (31) is hinged to the associated member (25) permanently fixed on the bars (11, 12) by means of U-shaped legs, said legs

20 extending through their respective opening (32, 33 and 34) in the pivotal plate-shaped body, and that stopping means (38, 39 and 40) are provided to stop the movement of the plate-shaped bodies (31) towards the cutting posi¬ tion in such a manner that said plate-shaped bodies are

25 automatically returned to the stirring position when the direction of rotation of the frame (4) Is reversed.

7. A cheese-making tank as claimed in one or more of the preceding claims 1 to 6 , c h a r a c t e r i s e d in that the plate-shaped bodies (10, 31) overlap one 0 another in the stirring position.

8. A cheese-making tank as claimed in one or more of the preceding claims l to 7, c h a r a c t e r i s e d in that the plate-shaped bodies (10, 31) are made of a plastic material, such as polyethylene or polypropylene.