GB2103533A - Moulding dough - Google Patents

Abstract

An apparatus for moulding pieces of dough comprises an endless belt 23 and a roller 33 arranged to compress and roll the pieces of dough. The belt and roller are driven in the same direction at different speeds to prevent dough jamming in the apparatus. Roller 33 is resiliently deformable to permit accommodation of dough pieces of various sizes. <IMAGE>

Description

SPECIFICATION Method and apparatus for moulding dough The present invention relates to a method and apparatus for moulding pieces of dough.

In the treatment of bread dough subsequent to mixing and prior to baking, at one stage the dough is subdivided into dough pieces having a weight corresponding to that of the ultimate product, that is a loaf of bread or a roll, and those dough pieces are moulded to a suitable shape for final proving and baking.

.In a conventional dough moulder the dough pieces are fed between two rollers which roll them out onto an endless belt which travels in a path such that the dough pieces in their rolled out state initially travel horizontally lying on the belt and then, as the belt turns about a supporting roller and is reversed in its direction of travel, each piece is folded against a restraining canvas and is then rolled between the belt (now uppermost) and an adjustable pressure board on which the pieces roll.

One of the disadvantages of conventional apparatus as described above is that the pressure board has to be quite finely adjusted to accommodate each particular weight of dough piece, and the operator must adjust the pressure board for each variation in weight as between dough pieces for various sizes of loaf or roll. Thus, where the apparatus is used in the same session for say bread rolls and large loaves, the operator must remember to adjust the pressure board in the intervals between the moulding of say 950 g dough pieces for loaves and the moulding of much smaller dough pieces for rolls, otherwise the machine will become jammed.

Usually when conventional apparatus jams it jams at the point where the belt reverses its direction about the belt supporting roller, that is the jam is usually between the roller and the canvas, which typically is about halfway along the path of travel between the inlet for the dough pieces and the outlet for the moulded dough pieces. Thus, conventional apparatus can jam in such a way that although dough pieces are being fed into the dough inlet, no moulded dough pieces emerge, however much the belt is rotated.

Thus, whenever conventional apparatus jams this means that the apparatus must be dis mantled in order to clear the stoppage and, because the belt and canvas become excessively coated with dough, they must be cleaned before the apparatus can be re-assem bled.

Another disadvantage of conventional appa ratus is that where the belt reverses its direction of travel about the roller the dough is often so folded as to envelope a significant amount of air, and air thus trapped in the dough can form one or more air pockets which lead to undesirable holes in the baked loaf.

I have now found surprisingly that the above disadvantages can be substantially avoided by rolling the dough pieces between closely adjacent surfaces both moving in the same direction but at different speeds, one surface being urged towards the other in a manner which allows the surface to yield to permit accommodation of dough pieces of various sizes between the surfaces.

Accordingly, the present invention in one aspect provides a method of moulding pieces of dough, which method comprises rolling the dough pieces between closely adjacent surfaces extending generally parallel to one another and both moving in the same direction but at different speeds, one surface being urged towards the other in a manner which allows the surface to yield to permit accommodation of dough pieces of various sizes between the surfaces.

Preferably, movement of the other surface away from said one surface is restrained.

In another aspect the invention also provides apparatus for moulding pieces of dough, which apparatus comprises two movable endless surfaces arranged so that for part of their endless paths they run closely adjacent each other and generally parallel, means to drive the surfaces in the same direction but at different speeds where they run closely adjacent and means to constrain within their path a dough piece sandwiched between the closely adjacent surfaces, one of the endless surfaces being resiliently deformable to allow that surface to yield, thereby to permit accommodation of dough pieces of various sizes between the surfaces.

Preferably in the apparatus of the invention the two movable endless surfaces run in arcuate paths where they run closely adjacent and generally parallel. Thus, the arcuate paths may be defined by two outer wheels of the same diameter flanking an inner wheel of smaller diameter, the wheels being mounted for rotation, the outer wheels preferably together and the inner wheel independently of the outer wheels.

With such an arrangement the faster endless surface may be provided by a belt having a longitudinal raised central section with a width just less than the width of the inner wheel whereby when the edges of the belt are carried on the outer wheels the raised section is accommodated within the annulus defined between the facing surfaces of the outer wheels and the outer circumferential periphery of the inner wheel.

Preferably, the slower endless surface is provided by the outer circumferential periphery of the inner wheel, and the inner wheel may comprise a rigid rim supporting a com pressible annulus, the circumferential peri phery of which provides an endless surface urged outwardly from the rim, the annulus being resiiiently deformable and thereby permitting the surface to yield continuously to accommodate dough pieces of various sizes.

Thus, in an especially preferred aspect the invention provides apparatus for moulding pieces of dough, which apparatus comprises two outer wheels of the same diameter flanking an inner wheel of smaller diameter, the wheels being mounted for rotation the inner wheel independently of the outer wheels, means to drive one and preferably both outer wheels at a circumferential speed in excess of that of the inner wheel and means (being the same or different) to drive the inner wheel in the same direction as the outer wheels, and a belt having a longitudinal raised central section having a width just less than the width of the inner wheel and arranged to travel in an endless path including a section in which the belt is carried with its edges outward of the raised section each on and drivable by an outer wheel with the raised section accommodated within the annuius defined between the facing surfaces of each outer wheel and the circumferential periphery of the inner wheel, the inner wheel comprising a rigid rim supporting a compressible annulus the circumferential periphery of which provides an endless surface urged outwardly from the rim which can resiliently deform thereby to permit accommodation of dough pieces of various sizes fed into the nip formed between the raised belt section and the said circumferential periphery, and the dough pieces can be rolled and moulded between the surface of the raised section of the moving belt and the circumferential periphery of the moving inner wheel when the belt is driven at a speed in excess of the speed of the inner wheel.

The apparatus of the invention substantially avoids the disadvantages of the conventional apparatus described herein. In particular, the apparatus of the invention can be used for dough pieces having any weight within the usual range of from about 50 gm to about 950 gm without the need to make any manual adjustment during operation. In addition, a dough piece fed into the apparatus will always emerge while the two surfaces are driven. Moreover, since the dough is rolled between relatively closely spaced surfaces there is little if any tendency to envelope air and trap air pockets in the moulded dough.

In operating the apparatus of the invention one surface, conveniently the belt on the outer wheels is preferably driven at a speed of about 5 times that of the other surface, that is the belt will preferably move about 5 times as fast as the outer peripheral surface of the inner wheel. Thus, as dough pieces are fed into the nip formed between the raised section of the belt and the circumferential periphery of the inner wheel the dough pieces are rolled and moulded between the belt and the peripheral surface by the different speeds of movement; moreover, because the inner wheel peripheral surface is moving as well as the belt, any dough piece fed into the nip will eventually emerge from between the belt and that peripheral surface where the belt leaves the outer wheels.In addition, because the inner wheel peripheral surface is that of a compressible annulus there is a continuous adjustment dictated by the size of the dough piece; thus, provided the annulus is chosen so that it can compress by a sufficient amount, any size of dough piece can be accommodated. Usually, it will be sufficient if the annulus can be compressed to a depth of about 2+ inches (6.5 cm) to accommodate dough pieces from roll size up to about 950 grams.

By a suitable choice of material for the compressible annulus a resiliently deformable surface can be formed which can deform by the necessary amount, and the compressibility of the annulus can be chosen so that the moulding achieved is gentle when compared with that of a conventional moulding apparatus. While any arrangement of compressible annulus may be used provided the arrangement can allow compression of the circumfer entiai surface sufficient to accommodate the size differential as between standard rolls and loaves, in one aspect of the invention it is preferred that the annulus comprises a compressible foamed plastics material. A number of suitable kinds of such material are well known and the annulus may be formed for example, of foamed polyurethane material or foamed rubber.

Since a foamed plastics material may not provide a surface which is acceptable in a commercial bakery, the compressible annulus when formed of such a material is preferably covered at least on its circumferential periphery by a belt of material such as canvas which complies with any food regulations which may be applicable.

Preferably, the covering belt is supported on a series of closely spaced plates disposed around the periphery of the inner wheel, the plates being carried on rods extending out wardiy from the rigid rim and arranged s;o that the plates can move to an outer limit when acted on only by the foamed material disposed between the plates and the rim and inwardly against the compressible foamed material when acted on by a dough piece urged against the belt.

In an alternative embodiment, the compres sible foamed material may be omitted and the plates urged outwardly from the rigid rim by other suitable arrangements such as by one or more springs. In any event there are preferably from about 20 to about 45, and more preferably about 32, plates spaced at equal distances around the rigid rim.

In a further alternative embodiment, the compressible annulus may comprise an outer rim of spring steel carried on a series of spring steel spokes. While the number and arrangement of spokes may be chosen to provide any necessary compressibility, typi cally there may be from about 20 to about 45 equally spaced spokes. Preferably the spokes of strip material are arranged inclined to the rim.

As with the inner wheel cover belt the other belt also must be made of a material such as canvas which meets food regulations. Further more, the other belt may have its raised section provided as a separate section which is affixed thereto, or the raised section may be formed integrally with the belt. Thus, where the belt is formed of a synthetic plastics material the raised section may be thermoformed or otherwise moulded into the belt cross-section.

The outer wheels may be formed of any suitable material which can support the endless belt and drive it, and that material again must meet any applicable food regulations.

Thus, the outer wheels may be formed of steel which may be stainless steel or coated steel, e.g. steel coated with a polytetrafluoroethylene material such as Teflon (registered Trade Mark).

If desired the apparatus of the invention may include an adjustable pressure board positioned adjacent the point where the endless surfaces diverge e.g. where the dough pieces leave the circumferential periphery of the inner wheel. By arranging the belt carried on the outer wheels so that it runs parallel with and above the pressure board, the board can be used to permit the moulded dough pieces to expand in length, i.e. to "run out" to various lengths. Alternatively, the width of the inner wheel may be increased and the yieldability of the circumferential periphery decreased such that any necessary "run out" occurs during the moulding stage.

The method and apparatus of the invention typically may be used in processing dough which has undergone initial proving and to mould dough pieces before any final proving prior to baking. However, if desired, the method and apparatus of the invention may also be used in the role of what is conventionally termed a "hander-up", that is to say in regularizing the shape of dough pieces before initial proving.

The method and apparatus of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows in diagrammatic form a conventional dough moulding apparatus; Figure 2 shows a side view of the belt and wheels arrangement of one form of apparatus in accordance with the present invention; Figure 3 shows an end view of the arrangement of the central wheels of the apparatus of Fig. 2; Figure 4 shows in diagrammatic form an arrangement of motor and drive belts for use in apparatus as shown in Fig. 2; Figure 5 shows a cross-section of an inner wheel for use in apparatus as shown in Fig. 2; Figures 6 to 8 show various arrangements to support the cover belt providing the inner wheel peripheral surface of Fig. 5; Figure 9 shows a cross-section of an alternative form of inner wheel; and Figure 10 shows a partially cut-away side elevation of part of the rim of the wheel of Fig. 9.

Referring to the drawings, a conventional apparatus as shown in Fig. 1 comprises a housing 11 having an inlet 1 2 and an outlet 20. Within the housing adjacent the inlet 1 2 are rollers 1 3 and 14, which rotate in the directions shown by the arrows, and disposed beneath rollers 1 3 and 14 is an endless belt 1 5 carried around rollers 1 6 and 1 7. Where the belt 1 5 changes direction around roller 1 7 a restraining canvas 1 8 is hung between the sides of the housing 11, and a pressure board 1 9 is positioned beneath the belt 1 5 with one end adjacent the canvas 1 8 and its other end adjacent the outlet 20.

In use dough pieces are fed into the moulding apparatus at inlet 1 2 and are rolled out by rollers 1 3 and 14. As the rolled out dough pieces leave rollers 1 3 and 14 they are picked up by the belt 1 5 which carries them along to roller 1 7 where they dough pieces are turned over and around and begin to roll against the restraining canvas 1 8. As the turning dough pieces emerge into the tunnel defined by the belt 1 5 and the pressure board 1 9 they are rolled along on the stationary pressure board 1 9 by movement of the belt 1 5 in the direction shown by the arrows.The belt movement rolls the dough pieces so that they are "run out" to the desired length depending on the pressure applied by the pressure board.

As described above, when the pressure board is not correctly adjusted and because the canvas 1 8 and the pressure board 1 9 are stationary, dough pieces fed into the inlet 1 2 and on to the belt 1 5 can become jammed where they reverse direction at a position remote both from the inlet 1 2 and from the outlet 20, as can be seen from Fig. 1. As discussed this necessitates dismantling and cleaning of conventional apparatus which can be time consuming and costly.

Referring to Figs. 2 to 5, one form of apparatus in accordance with the invention comprises an endless belt 23 supported on rollers 24 to 28, roller 27 including a device 29 for adjusting the tension of the belt 23 as necessary. The belt 23 has a raised central section 32 which runs the whole length of the belt and is proportioned so that it fits snugly between wheels 33 and 34. The remainder of the belt comprising edges 31 is carried supported for a part of its endless path on the respective outer peripheries of wheels 33 and 34.

The wheels 33 and 34 flank an inner wheel 35 which comprises a rigid rim 36 carried on spokes 37. The rim 36 in turn carries a multiplicity of plates 39 each supported on a pair of rods 51 and urged outwardly from the rim by various means as described in more detail below. The plates are covered by a canvas belt 40 which provides the outer circumferential periphery of the inner wheel.

Spokes 37 are fixed to a hub locked on an axle 41 about which wheels 33 and 34 can freely rotate. Each wheel 33 and 34 carries a drive wheel 42 and 43 respectively around which a drive belt can pass to drive those wheels. On one end of the axis beyond drive wheel 42 is another drive wheel 44 for the purpose of driving the axle 41 and the inner wheel 35 fixed thereto.

Referring in particular to Fig. 4 it will be seen that a motor 45 can be disposed so that a first drive belt 46 passes around drive wheel 44 to drive the inner wheel at one speed, and a second drive belt 47 is led to an arrangement of two wheels, one of which is shown at 48 disposed at opposite ends of a shaft (not shown) so that drive belt 49 and a corresponding drive belt on the other side of the apparatus can drive wheels 33 and 34 at another and the same speed. The drive is arranged so that the wheels 33 and 34 are driven at a peripheral speed of about 5 times that of the inner wheel 35.

Referring to Figs. 5 to 8, the canvas cover belt 40 which forms the outer periphery of the compressible annulus 38 is carried on a multiplicity of plates 39 each supported on a pair of rods 51. The plates 39 may be flat as shown in Figs. 6, 7 and 8 for moulding conventional loaves or rolls, or they may be curved as shown in Fig. 6bfor moulding bridge rolls and Vienna leaves etc. with pointed ends. Each rod 51 passes through a hole 53 in the rim 36 and its movement outwards from the rim is restrained by a split pin 52 or other suitable stop means. (For clarity the arrangements of Figs. 6 to 8 are shown slightly compressed).

In the arrangement shown in Fig. 6 a tyre 54 of foamed plastics material is carried on the rim 36 wedged between the rods 51 to each side, the rim 36 beneath, and the plates 39 about. In its essentially uncompressed state the tyre 54 holds rods 51 with split pins 52 held against the undersurface of the rim 36 so that all of the plates form a cylindrical circumferential periphery covered by the belt 40.

In an alternative arrangement as shown in Fig. 7 each rod 51 carries a spring 56. In this case the rods 51 and the plates 39 carried on them are urged to their outer limits by the springs, and again the plates form a cylindrical circumferential periphery covered by the belt 40. In yet another but similar arrangement as shown in Fig. 8, a central unrestrained rod 57 carries a single spring 58.

In a typical embodiment of the apparatus of the invention the outer wheels comprise stainless steel or Teflon coated steel and have a diameter of about 65 cm. With outer wheels of that size the inner wheel typically has a diameter of 60 cm and the raised section of the belt has a depth such that there is a gap of about 1 cm between the surface of the raised section and the outer peripheral surface of the inner wheel. Suitably, the raised section of the belt may be about 1 5 cm wide and the belt may be 30 cm wide overall. To complement those dimensions the inner wheel has a width of about 1 5 cm and each outer wheel a width of about 7.5 cm.

Although only five rods and plate combinations are shown in Fig. 5 there typically may be 32 plates 39 having a width of, for example, 2.5 cm supported and outwardly urged as described. As shown at 59 in Fig. 5 the cover belt 40 and its supporting plates 39 may be differentially depressed towards the rim 36 and the annulus 38 is arranged so that the cover belt 40 can be depressed by amounts ranging from that required to accommodate the dough piece of a roll and that required to accommodate the dough piece of a large loaf. With the above wheel dimensions and provided the compressible annulus is formed so that it can be compressed by up to about 6.5 cm, the moulding apparatus shown can with facility accommodate dough pieces in a variety of sizes from bread rolls up to large loaves.

As shown in Fig. 2 an adjustable pressure board 61 may be positioned adjacent outlet 62 where the dough pieces leave the surface of the inner wheel.

In use dough pieces are fed into the inlet 60 at the nip formed between the upper surface of the raised section of the belt and the outer peripheral surface of the inner wheel 35 as provided by the cover belt 40. As the belt 23 is driven around its path by the movement of the rollers 33 and 34 each dough piece is rolled between the belt 23 and the inner wheel 35, while being constrained within the necessary path by the tops of the outer wheels 34 and 35. This achieves the necessary moulding of each dough piece in the path between the nip 60 and the outlet 62, and at the outlet 62 the pressure board may be adjusted to achieve any necessary run out" to increase the length of the moulded dough piece.

Alternatively the width of the inner wheel may be increased and the yieldability of the annulus 38 may be decreased so that the necessary "run out" may be effected in the path between the inlet 60 and the outlet 62.

Referring to Figs. 9 and 10, these show an inner wheel 70 comprising a riqid rim 71 carried on spaced circular walls 72 and 73.

The wheel is mounted for rotation on an axle 74 and adjacent the axle the walls each carry a countersunk hub member 75 and 76 to which the axle is locked.

The rigid rim 71 carrries a series of spring steel spokes 77 which extend upwardly from the rim and at their ends remote from the rim are connected to cross members 78. The cross members 78 support a second rim 79 of spring steel. A flexible cover 80 is disposed to either side of the compressible rim 79 to prevent dough entering between rims 79 and 71.

Walls 72 and 73 may be formed of wood or rigid plastics material and the hubs 75 and 76 may be formed of metal. Typically the inner wheel thus formed is 6 inches wide and the spokes are 3 inches wide.

It is to be understood that the invention is not limited to the above embodiments. Thus for example, a number of alternative drive arrangements may be used and in one such arrangement the motor may be disposed above the inner and outer wheels rather than below as shown in Fig. 4.

Claims (23)

1. Apparatus for moulding pieces of dough, which apparatus comprises two movable endless surfaces arranged so that for part of their endless paths they run closely adjacent each other and generally parallel, means to drive the surfaces in the same direction but at different speeds where they run closely adjacent and means to constrain within their path a dough piece sandwiched between the closely adjacent surfaces, one of the endless surfaces being resiliently deformable to allow that surface to yield, thereby to permit accommodation of dough pieces of various sizes between the surfaces.

2. Apparatus according to claim 1, wherein the two movable endless surfaces run in arcuate paths where they run closely adjacent and generally parallel.

3. Apparatus according to claim 2, wherein the arcuate paths are defined by two outer wheels of the same diameter flanking an inner wheel of smaller diameter, the wheels being mounted for rotation.

4. Apparatus according to claim 3, wherein the outer wheels are mounted for rotation together and the inner wheel is mounted for rotation independently of the outer wheels.

5. Apparatus according to claim 3 or claim 4, wherein the faster endless surface is provided by a belt having a longitudinal raised central section with a width just less than the width of the inner wheel whereby when the edges of the belt are carried on the outer wheels the raised section is accommodated within the annulus defined between the facing surfaces of the outer wheels and the outer circumferential periphery of the inner wheel.

6. Apparatus according to any one of claims 3 to 5, wherein the slower endless surface is provided by the outer circumferential periphery of the inner wheel, and the inner wheel comprises a rigid rim supporting a compressible annulus, the circumferential periphery of which provides an endless surface urged outwardly from the rim, the annulus being resiliently deformable and thereby permitting the surface to yield continuously to accommodate dough pieces of various sizes.

7. Apparatus for moulding pieces of dough, which apparatus comprises two outer wheels of the same diameter flanking an inner wheel of smaller diameter, the wheels being mounted for rotation the inner wheel independently of the outer wheels, means to drive at least one outer wheel at a circumferential speed in excess of that of the inner wheel, means being the same or different to drive the inner wheel in the same direction as the outer wheels, and a belt having a longitudinal raised central section with a width just less than the width of the inner wheel and arranged to travel in an endless path including a section in which the belt is carried with its edges outward of the raised section each on and drivable by an outer wheel with the raised section accommodated within the annulus defined between the facing surfaces of each outer wheel and the circumferential periphery of the inner wheel, the inner wheel comprising a rigid rim supporting a compressible annulus the circumferential periphery of which provides an endless surface urged outwardly from the rim which can resiliently deform thereby to permit accommodation of dough pieces of various sizes fed into the nip formed between the raised belt section and the said circumferential periphery, and the dough pieces can be rolled and moulded between the surface of the raised section of the moving belt and the circumferential periphery of the moving inner wheel when the belt is driven at a speed in excess of the speed of the inner wheel.

8. Apparatus according to claim 6 or claim 7, wherein the compressible annulus is constructed so that it can be compressed to a depth of about 6.5 cm to accommodate dough pieces from roll size up to about 950 grams.

9. Apparatus according to any one of claims 6 to 8, wherein the annulus comprising a compressible foamed plastics material.

10. Apparatus according to claim 9, wherein the foamed plastics material is covered at least on its circumferential periphery.

11. Apparatus according to claim 10, wherein the covering is supported on a series of closely spaced plates disposed around the periphery of the inner wheel, the plates being carried on rods extending outwardly from the rigid rim and arranged so that the plates can move to an outer limit when acted on only by the foamed material disposed between the plates and the rim and inwardly against the compressible foamed material when acted on by a dough piece urged against the covering.

1 2. Apparatus according to any one of claims 6 to 8, wherein the compressible annulus comprises an outer covering supported on a series of closely spaced plates disposed around the periphery of the inner wheel, the plates being carried on rods extending outwardly from the rigid rim, the plates being associated with springs arranged so that the plates can move to an outer limit when acted on only by the springs disposed between the plates and the rim and inwardly against the springs when acted on by a dough piece urged against the covering.

1 3. Apparatus according to any one of claims 6 to 8, wherein the compressible annulus comprises an outer rim of spring steel carried on spring steel spokes.

1 4. Apparatus according to claim 13, wherein the spokes comprises strip material and are arranged inclined to the rim.

1 5. Apparatus according to any one of claims 3 to 14, wherein the outer wheels are formed of steel.

1 6. Appparatus according to any one of the preceding claims which includes an adjustable pressure board positioned adjacent the point where the endless surfaces diverge arranged to permit run out after moulding.

1 7. Apparatus according to any one of claims 6 to 15, wherein the width of the inner wheel is increased and the yieldability of the circumferential periphery decreased such that the apparatus can provide run out during moulding.

18. Apparatus for moulding pieces of dough substantially as hereinbefore described with reference to and as illustrated in Figs. 2 to 4, taken with any one of Figs. 5 to 10, of the accompanying drawings.

1 9. A method of moulding pieces of dough, which method comprises rolling the dough pieces between closely adjacent surfaces extending generally parallel to one another and both moving in the same direction but at different speeds, one surface being urged towards the other in a manner which allows the surface to yield to permit accommodation of dough pieces of various sizes between the surfaces.

20. A method according to claim 19, wherein movement of the other surface away from said one surface is restrained.

21. A method according to claim 19 or claim 20, wherein the dough pieces have a weight of from about 50 gm to about 950 gm.

22. A method according to any one of claims 19 to 21, wherein one surface is driven at a speed of about 5 times that of the other surface.

23. A method according to claim 19 and substantially as hereinbefore described specifically.