Rolling up a sheet of dough

Abstract: Apparatus for making a rolled bread product such as a croissant, which is arranged to prevent a sheet of dough (50) from being loosely rolled up, to prevent the sheet from being unevenly rolled up, and to firmly roll up the sheet. The apparatus includes a conveyor (11) that feeds the dough sheet and a rolling up roller (31) that is moveable up and down above the conveyor, so that the rotation of the rolling up roller and the feeding action of the conveyor cause the dough sheet to be firmly rolled up.

Description: This invention relates to a method and apparatus for rolling up a sheet of dough when processing bread, confectionery, and the like. More particularly it relates to a method and apparatus for rolling up a piece of a dough sheet, for example when making croissants, or a piece of a dough sheet on which fillings such as sausages, pieces of cheese, pieces of chocolate, creamy materials, jam, and the like have been placed. There are many examples in the prior art of apparatus for rolling up a sheet of dough. For example, one such prior art apparatus is provided with a conveyor belt above which a plate or a belt is positioned so that a gap is defined between them. When a sheet of dough is passed through the gap, it is rolled up. A similar apparatus using a roller is shown in DE 2709544. GB 2075906 discloses an apparatus for rolling a sheet of sponge cake material into a roll. The sheet is carried on a plurality of conveyor belts, and is rolled up through contact with a number of individual rollers mounted on a common shaft. The conveyor belts deflect downwardly to accommodate the roll as its diameter increases. In use of such an apparatus, when a substantially triangular sheet of dough for forming a croissant is to be rolled up, it is located on the conveyor with its base side facing in the downstream direction and intersecting the feeding direction of the conveyor at right angles. Then, the apparatus starts rolling up the sheet from its base side. However, the sheet may not be properly rolled up, due to its various characteristics. Thus the sheet may be loosely rolled up, or it may not be rolled up at all but may be deformed when it passes by a rolling up roller, or it may be unevenly rolled up across its width. A device has been proposed for preventing such a dough sheet from being loosely rolled up, as disclosed in Japanese Patents Laid-open Nos. 61-271939 and 63-22132. Another device has been proposed for preventing just a part of a sheet from being loosely rolled up, as disclosed in Japanese Patent Laid-open No. 62-61533. However, these devices do not make a tight core when they start rolling up a sheet of dough. Thus they cannot firmly roll up the dough sheet, so that they still do not overcome the problems of the prior art apparatus. Also, no apparatus has yet been made to successfully roll up a sheet of dough on which solid pieces have been placed. Also, in apparatus of the prior art, some elements have to be adjusted or replaced according to the thickness of the sheet of dough and/or the diameter of a roll, which makes the apparatus more expensive. Viewed from one aspect the present invention provides method of rolling up a sheet of dough, comprising feeding the sheet on a conveyor, rotating a rolling up roller in the opposite direction to the feeding direction of the conveyor, the rolling up roller being positioned above the conveyor and comprised of a plurality of elemental rollers arranged along an axis of the rolling up roller, each elemental roller being separately movable up and down, feeding the sheet on the conveyor to the rolling up roller, starting rolling up the sheet with at least one of the elemental rollers of the rolling up roller by kicking up the leading end of the sheet, and continuing to roll up the sheet by means of the rotation of the rolling up roller and the movement of the conveyor, each of the elemental rollers moving up and down according to the thickness of the sheet being rolled up. Viewed from another aspect the invention provides apparatus for rolling up a sheet of dough, comprising a conveyor for feeding the dough sheet, and a rolling up roller, the rolling up roller being positioned above the conveyor and arranged to rotate in the opposite direction to the feeding direction of the conveyor, and being comprised of a plurality of elemental rollers arranged along an axis of the rolling up roller, each roller being separately movable up and down. The apparatus may further comprise driving means arranged to rotate and support the rolling up roller in such manner that each elemental roller of the said rolling up roller can move up and down. The said driving means may include an internal gear formed on the inner surface of the rolling up roller, a pinion gear that is made to mesh with the internal gear, and a positioning roller arranged to urge the rolling up roller to a position where its axis is downstream of that of the said pinion gear. Preferably the said positioning roller is located upstream of the rolling up roller and is arranged to contact the surface of the sheet. The said rolling up roller may be mounted between two rollers. The said rolling up roller may be arranged to swing around a point that is above its axis, so that it can move up and down. Two embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:- Fig. 1 is a perspective view of a first embodiment; Fig. 2 is a side view of a first embodiment of a rolling up roller; Fig. 3 is another side view of the rolling up roller, to a larger scale; Figs. 4 and 5 are side views of a second embodiment of a rolling up roller; Figs. 6a-6d are views to illustrate the function of the roller of the second embodiment; and Figs. 7a, 7b and 7c show a prior art apparatus. As seen in Fig. 1, a rolling up apparatus according to this invention includes a feeding means 10 in the form of a conveyor belt 11 on which triangular pieces 50 of dough (which are to be made into croissants in this embodiment) are conveyed. When being so conveyed, the base side of each triangular piece 50 faces in the downstream direction of the conveyor belt 11, i.e. the direction shown by the arrow in this figure. A rolling up roller 31 rolls up the dough pieces 50, as it rotates. In more detail, a driving shaft 21 is located horizontally above and across the conveyor belt 11. Frames 23 rotatably and freely support the opposite ends of the driving shaft. The shaft extends through, and is secured to, disks 22 one near to each of its opposite ends. The disks 22 contact the conveyor belt 11 and thus, as the conveyor belt moves, the disks 22 are rotated and thereby the driving shaft 21 is rotated. Another driving shaft 27 extends above and across the conveyor belt 11 at a position upstream from the driving shaft 21. The driving shaft 27, which rotates the rolling up roller 31, is driven by the driving shaft 21 through meshing gears 28 and 29 fixed to the ends of the shafts 21 and 27 respectively. A plurality of pinion gears 20 of relatively small thickness are fixed on the driving shaft 27. In an alternative embodiment a single, much thicker pinion gear could be fixed on the shaft. The rolling up roller 31 is divided into a plurality of elemental rollers each of which has an internal gear 32, as shown in Fig. 2, which meshes with a respective pinion gear 20. Instead of the meshing of the internal gears 32 and the pinion gears 20, frictional wheels may be used. Flanges 35 (Fig. 3) may be formed on opposite ends of the roller 31 or each elemental roller, to prevent the internal gears 32 on the rollers 31 from sliding on the pinion gears 20 and disengaging from them. The outer surface of the rolling up roller 31 is covered by belts 33, made of rubber. An additional roller 40 is located upstream of the roller 31 and parallel to the same. The roller 40 pushes against the rolling up roller so that the axis of the latter is shifted to a position downstream of the axis of the pinion gear 20, which lies within the cavity of the rolling up roller. Thus, each elemental roller of the rolling up roller 31 can be generally swung around the point where the associated pinion gear 20 meshes with its internal gear 32. A nominal gap is maintained between the rolling up roller 31 and the conveyor belt 11, which can be adjusted according to the thickness of the dough sheet. The roller 40 comprises a plurality of disks 41 fixed on a shaft 42. Round belts 43 extend around the circumferential surfaces of the disks 41. A gap is maintained between the belts 43 and the conveyor belt 11, so that the dough pieces 50 can pass therethrough. The gap can be adjusted according to the thickness of the dough sheet. A bar 44 of small diameter is located parallel to the roller 40 and downstream thereof, as shown in Fig. 2. The roller 40 and the bar 44 are rotated by the driving shaft 21 through pulleys 24, 25 and 26. The bar 44 acts to remove a dough piece 50 from the surface of the roller 40 if the dough piece adheres thereto. In operation, when the conveyor belt 11 starts to feed the dough pieces 50, the disks 22 are rotated by the conveyor belt. As a result the shaft 27 is rotated through the gears 28 and 29. Such rotation of the shaft 27 and the pinion gear 20 causes the rolling up roller 31 to be rotated in the direction opposite to the feeding direction of the conveyor belt 11. Also, by way of the pulleys 24,25, and 26, the roller 40 is rotated in the opposite direction to the roller 31. As the conveyor 11 operates, a dough piece 50 enters the gap between the disks 41 of the roller 40 and the conveyor. As the dough piece 50 passes through the gap, it is fed by the round belts 43. If it adheres to the belts 43 the bar 44 removes it. When the base side of the dough piece 50 contacts the rolling up roller 31, the belt 33 on the roll-up roller 31 kicks up the edge of the dough piece. The dough piece is thereby bent so that a firm core is formed, whereby to make a firmly rolled up piece. Because the belt 33 is made of rubber friction is enhanced between it and the dough piece 50, and the belt positively grips the edge of the dough piece. As the conveyor belt 11 continues to feed the dough piece 50, the rolling up roller 31 rolls it up progressively. As the diameter of the dough piece thereby increases, the rolling up roller 31 is gradually swung by the rolled up dough piece around the point where the pinion gear 20 meshes with the internal gear 32. As a result, the roller 31 is lifted, and the gap between it and the conveyor 11 increases. The feeding rate of the conveyor belt 11 is higher than the speed of the external surface of the roller 31 when it rotates. Consequently the dough piece continues to advance along the conveyor belt 11 and passes through the gap between the rolling up roller 31 and the conveyor belt. As it passes through the gap, the roller 31 suitably presses it. In more detail, Figs. 6a-6d show the dough piece 50 being rolled up as it is fed in the downstream direction. As seen in Fig. 6a, the rolling up roller 31 first contacts the base edge of the dough piece, so that the edge is kicked up by the surface of the roller. Then, as shown in Fig. 6b, the roller 31 can easily grip and bend the edge. The roller 31 presses the downstream side of the dough piece 50 as it rolls it up. As seen in Figs. 6c and 6d, as the diameter of the rolled up dough piece increases, the gap between the roller 31 and the conveyor belt 11 increases. Also, as the diameter increases, the angle at which the outer surface of the rolling up roller contacts the dough piece decreases. When the dough piece is substantially fully rolled up, the roller 31 contacts the dough piece 50 from above, so that the roller 31 presses the upstream side of the dough piece 50. Thus the pressing force from the rolling up roller 31 acts over the entire surface of the dough piece in the process of rolling it up. The prior art apparatus which uses a horizontal plate to roll up a dough piece cannot act in this way. When the rolling up roller 31 starts rolling up the dough piece as shown in Fig. 6a, the round belts 43 hold the dough piece on the conveyor belt 11. Consequently the roller 31 is able to stably grip the dough piece as it starts to roll it up, and is thereby prevented from rolling up the dough piece unevenly. As explained above with reference to Fig. 1, the rolling up roller 31 is made up of a plurality of elemental rollers, along its axis. As previously mentioned, each such elemental roller can separately be swung around the position where the pinion gear 20 meshes with the internal gear 32. If, as in this embodiment, the dough piece 50 is rolled up to make a somewhat spindle-shaped product, such as a croissant, the diameter of the product is not constant along its length. However, when such a dough piece passes through the gaps between the elemental rollers and the conveyor belt 11, the elemental rollers can move up separately according to the differing diameter of the product. As a result, each of the elemental rollers can properly press a respective part of the product, even though the diameter of the rolled up dough piece is not constant. Also, as described above, the rolling up roller 31 holds the dough piece 50 so as to grip it sufficiently as it is rolled up and conveyed by the conveyor belt 11. Thus, even if solid filings, such as sausages, pieces of cheese, pieces of chocolate and the like, are placed on the dough piece 50, it can still be firmly rolled up by the roller 31. Figs. 4 and 5 show apparatus 60 according to another embodiment of this invention. A rolling up roller 61 is held between a roller 62 and a driven roller 63, connected a link bar 64. The roller 62 is located upstream of the driven roller 63 and is directly connected to a drive motor (not shown). The driven roller 63 and the link bar 64 can be swung relative to the roller 62, which also causes the roller 61 to be swung around the roller 62. The rollers 61,62, and 63 are formed with meshing gears at their adjacent ends. A roller 65 is located to press down on the dough piece 50 as it is fed, so that the roller 61 firmly rolls it up. As a dough piece 50 is rolled up, its thickness increases. As the thickness increases, the rollers 61 and 63 are lifted by the dough piece, while at the same time it is fed in the downstream direction. Thus the apparatus 60 generates an effect that is similar to that of the first embodiment.

Claims: A method of rolling up a sheet of dough (50), comprising feeding the sheet on a conveyor (11), rotating a rolling up roller (31, 61) in the opposite direction to the feeding direction of the conveyor, the rolling up roller being positioned above the conveyor and comprised of a plurality of elemental rollers arranged along an axis of the rolling up roller, each elemental roller being separately movable up and down, feeding the sheet on the conveyor to the rolling up roller, starting rolling up the sheet with at least one of the elemental rollers of the rolling up roller by kicking up the leading end of the sheet, and continuing to roll up the sheet by means of the rotation of the rolling up roller and the movement of the conveyor, each of the elemental rollers moving up and down according to the thickness of the sheet being rolled up. Apparatus for rolling up a sheet of dough (50), comprising a conveyor (11) for feeding the dough sheet, and a rolling up roller (31, 61), the rolling up roller being positioned above the conveyor and arranged to rotate in the opposite direction to the feeding direction of the conveyor, and being comprised of a plurality of elemental rollers arranged along an axis of the rolling up roller, each roller being separately movable up and down. Apparatus as claimed in claim 2, further comprising driving means (20) arranged to rotate and support the rolling up roller in such manner that each elemental roller of the said rolling up roller can move up and down. Apparatus as claimed in claim 3, wherein the said driving means includes an internal gear (32) formed on the inner surface of the rolling up roller (31), a pinion gear (20) that meshes with the internal gear, and a positioning roller (40) arranged to urge the rolling up roller to a position where its axis is downstream of that of the said pinion gear. Apparatus as claimed in claim 4, wherein the said positioning roller (40) is located upstream of the rolling up roller (31), and is arranged to contact the surface of the dough sheet. Apparatus as claimed in claim 2, wherein the said rolling up roller (61) is mounted between two rollers (62,63). Apparatus as claimed in any of claims 2 to 6, wherein the rolling up roller (31, 61) is arranged to swing around a point that is above its axis, so that it can move up and down.

Inventors: UENO SADAO, UENO, SADAO
Applicants: RHEON AUTOMATIC MACHINERY CO, RHEON AUTOMATIC MACHINERY CO., LTD.
Application year: 1998
Main classification: A21C3
IPC codes: A21C3