An apparatus for rolling dough pieces

Abstract: An apparatus for rolling, in particular, croissant pieces, dough pieces, are provided, in which dough pieces are fed between a pair of rollers (5,7) and transferred to an endless belt device (9) via a transfer roller (13,15) of a small diameter and high speed rotation for peeling off the dough piece from the roller. Then the dough pieces are carried under a rollling up device (11) to be rolled into croissant rolls. The dough pieces are transferred to the endless belt maintaining at least one surface of it adhesive, and so the dough rolls produced are wound tightly due to the dough surfaces adhering to each other.

Description: This invention relates to an apparatus and method for rolling up dough pieces and particularly to an apparatus and method for rolling up croissant dough pieces without an operational error and at minimum costs. U.S. Patent No. 2,677,334 teaches a pressure board for a bread dough molding machine, in which a first endless belt device receiving the dough pieces passed between presheeting rolls, a second endless belt device positioned below the first endless belt device, a curling screen positioned above the second endless belt device and a transfer plate for transferring the dough from the first endless belt device to the second endless belt, are provided. In this apparatus the dough piece provided on the first endless belt device passes over the transfer plate. Then the dough piece is received on the second endless belt device, which carries the dough piece under the curling screen thereby rolling it into a roll. In this apparatus the surface of the endless belt is provided with flour powder to prevent the dough piece from adhering to the belt surface so that the dough piece can be transferred through the endless belt devices and roller pairs smoothly. Thus, both surfaces of the dough, which contact the flour on the endless belt and roller pairs, lose their adhesiveness, and this loss is disadvantageous in that the surfaces do not stick to each other, and this results in the dough roll being wound loosely. Additionally, such a dough roll is readily loosened afterwards. U.S. Patent Application No. 867,815, assigned to the present applicant, teaches an apparatus and method for producing croissants in which a dough piece rolling up mechanism having a lower endless belt device and an upper endless belt device, a feeding endless belt device, a pair of vertically juxtaposed rollers positioned between the rolling up mechanism and the feed conveyor and a roller of a small diameter being adjacent the peripheral surface of the lower roller and rotated faster in its peripheral speed than the peripheral speed of the lower roller are provided. In this apparatus, a tip of the dough piece reaching the upstream end of the lower endless belt device is detected by a sensor and rolled into a roll by narrowing the gap between the upstream ends of the endless belt devices. But to do such an operation at least a sensor, means for lowering and raising the endless belt, and a control unit to activate the lowering and raising means to cooperate with the sensor, are required, and such a construction makes the apparatus complicated and expensive. Also known from the prior art are US-A-3748073 and FR-A-2477378, the latter disclosing the preamble of claim 1. The present invention is characterised in that two transfer rollers, each of a diameter significantly less than that of said pair of rollers are positioned downstream thereof and are rotatable in the direction of the movement of the dough pieces, and in that each of said transfer rollers is positioned in contact with or adjacent the peripheral surface of each of said pair of rollers, the peripheral speed of said transfer rollers being faster than that of each of said pair of rollers, whereby, when the dough piece is carried out of said pair of rollers, one of the surfaces of the dough piece can selectively adhere to the surface of either of the pair of rollers according to the adhesiveness of the respective dough piece surfaces, and then the leading tip of the dough piece can be peeled off from said selectively adhering roller surface by the relevant one of said transfer rollers. By means of this arrangement, at least in preferred forms, there is provided an apparatus for rolling croissant dough pieces, accurately and tightly without loosening or producing irregular rolls, using a simple configuration. A transfer roller is provided adjacent each of the pair of the upper and lower rollers, and the dough pieces are readily and accurately peeled off from whichever roller they adhere to and are transferred to the endless belt device. Additionally, the surfaces of the rollers and the upper flight of the endless belt need not be covered by flour powder to transfer the dough pieces smoothly. The dough pieces carried in the apparatus have at least one surface adhesive. Therefore, the surfaces adhere to each other when the dough pieces are rolled, resulting in a croissant dough roll wound tightly as well as preventing loosening afterwards. An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings, in which:- Fig. 1 is a schematic illustration showing the feeding and rolling of dough pieces, in an embodiment of the present invention. In Fig. 1 an apparatus for rolling croissant dough 1 of an embodiment is shown comprising a first endless belt device 3 for feeding dough pieces 4, a pair of vertically juxtaposed rollers consisting of an upper roller 5 and a lower roller 7 arranged downstream of the first endless belt device 3. A second endless belt device 9 is provided downstream of the pair of rollers 5,7 and a flexible screen 11 of cloth or metal net is suspended from a holder spaced apart from and above the second endless belt device 9 as a rolling up device for rolling dough pieces. The upper roller 5 and the lower roller 7 are positioned vertically spaced apart from each other by a distance shorter than the thickness of dough pieces to press the dough piece between them. A lower transfer roller of a small diameter 13 is provided between the lower roller 7 and the upstream end of the second endless belt device 9 with the lower transfer roller 13 contacting or adjacent the peripheral surface of the lower roller. Similarly an upper transfer roller of a small diameter 15 is provided between the upper roller 5 and the upstream end of the second endless belt device 9 with the transfer roller 15 contacting or adjacent the peripheral surface of the upper roller 5. Since the lower transfer roller 13 is provided to peel off and transfer dough pieces adhering to the peripheral surface of the lower roller 7, it is preferable that the transfer roller 13 is designed to have a surface area as small as possible to avoid adhering to the dough pieces. It has been found that the transfer roller should preferably have a diameter of one-fourth the length of the dough piece in the feeding direction, at maximum, to attain a reliable peeling off operation. The upper transfer roller 15 is provided to peel off and transfer dough pieces adhering to the peripheral surface of the upper roller 5 and its construction and function are the same as those of the lower transfer roller 13. The first endless belt device 3 and the second endless belt device 9 are driven by driving motors 17,19 respectively and the upper and lower rollers 5,7 are driven in the same direction where they face each other by driving motors 21,23 respectively. The lower transfer roller 13 and the upper transfer roller 15 are driven by their respective driving motors (not shown) to rotate in the direction of movement of the dough pieces, which direction is the same as that of the movement of the upper and lower rollers 5,7 where they face each other, with the speed faster than the peripheral speed of the rollers 5,7. The operation of rolling the croissant dough piece will now be described in detail. A triangular croissant dough piece 4 on the first endless belt device 3 is fed into the space between the upper roller 5 and the lower roller 7 with the base of the triangle as the leading end. Since the rollers are vertically positioned by a distance shorter than the thickness of the dough piece 4, the dough pieces 4 are stretched by pressure from the rollers 5,7 when they pass between them. In this apparatus, flour powder is not provided on the peripheral surfaces of the rollers 5,7. Thus the dough piece 4 is carried by the rollers 5,7 while adhering to the surfaces when it is stretched. Without flour powder, the dough piece 4 would adhere to the surface of either of the rollers, for example, the lower roller 7, and is carried forward. However, when the dough piece 4 reaches and contacts the lower transfer roller 13 rotating at a speed higher than the peripheral speed of the lower roller 7, the leading tip of the dough piece 4 is peeled off from the roller surface and transferred to the second endless belt via the lower transfer roller 13. To ensure a reliable peeling off operation, it is found that the transfer roller 13 is also preferably designed to have a diameter of one-fourth or less the length of the dough piece 4 measured in the feeding direction and be driven faster in its peripheral speed than the peripheral speeds of the upper and lower rollers 5,7. Where the transfer roller 13 does not have the diameter and rotating speed described above, and particularly where the transfer roller 13 is driven more slowly than the peripheral speed of the pair of upper and lower rollers 5,7, the dough piece 4 becomes stagnant when it reaches the transfer roller 13 and adheres to its peripheral surface. Otherwise, if the transfer roller 13 has a diameter larger than one fourth the length of the dough piece 4, it has a relatively large surface area resulting in the dough piece sticking to its own surface. Therefore the dough piece 4 cannot be transferred to the second endless belt device 9. Regarding the upper transfer roller 15, the same peel off operation takes place at the upper transfer roller 15. Thus it is designed to have similar conditions as those of the lower transfer roller 13 regarding the diameter and the peripheral speed. Then the dough 4 is carried on the second endless belt device 9 onto the flexible screen 11. Since the second endless belt device 9 is not provided with flour powder either, the lower side surface of the dough piece 4 is adhesive to the upper flight surface of the second endless belt device 9. As is well known in the art, the flexible screen 11 is positioned above the upper flight of the second endless belt device 9 suspended from a horizontal holder positioned transversely of and spaced apart from the endless belt device, the holder being supported on both ends by standing arms. The dough piece 4 carried under the flexible screen 11 is curled up by the screen from its leading tip. Since the upper flight surface of the belt device 9 is not covered with flour powder, the lower surface of the dough piece 4 is kept adhesive. When the dough begins to curl up, the leading tip of the dough is caught by the screen securely by adhering to the surface of the screen 11 and is rolled up tightly with its surfaces sticking to each other due to their adhesiveness. Moreover, because the surfaces of the dough pieces stick to each other, once the dough piece 4 is rolled up, the dough roll hardly loosens. When the dough piece 4 is completely rolled up, it exits from the space between the screen 11 and the upper flight surface. In this apparatus, the upper flight of the second endless belt device 9 is driven to move faster than the peripheral speed of the pair of upper and lower rollers 5,7 and is positioned near the pair of upper and lower rollers 5,7 at a position where the distance between the upstream end of the second endless belt device 9 and a point where the pair of the rollers 5,7 are the closest is shorter than the length of the dough piece measured in the feeding direction. When the croissant dough piece 4 of a triangular shape, fed with its base as a leading end, passes between the pair of rollers 5,7 and is transferred to the second endless belt 9 via the transfer rollers 13,15, the top of the triangle is held between the pair of rollers 5,7 while its base portion is located on the second endless belt device 9. Since the upper flight of the second endless belt 9 moves faster than the peripheral speed of the pair of rollers 5,7 the dough piece is pulled by the second endless belt device 9 in the moving direction of the upper flight of the second endless belt device while the top of the triangle is held between the rollers 5,7. The croissant dough piece 4 is fed to the rollers 5,7 and the second endless belt device 9 with the base of the triangle perpendicular to the moving direction to prevent the dough piece from being rolled up irregularly. That is, to form a regular croissant roll, it is important to bring the base of the triangle of the dough piece to form the axis of the roll. If the base of the triangle is not positioned perpendicularly to the moving direction of the dough piece, the dough piece will result in a distorted spindle-form roll unsuitable for eating. However, in this apparatus, even when the dough 4 is positioned aslant and the base of the triangle is not positioned perpendicularly to the moving direction of the endless belt, the position of the dough piece 4 is corrected by the pulling at the base so that the line from the top to the center of the base of the triangle is aligned with the moving direction of the second endless belt device 9. The faster driven second endless belt device 9 imparts force to the dough piece so as to correct its orientation. As described above, a dough piece is stretched by a pair of rollers and is transferred to a rolling up device by an endless belt while maintaining adhesiveness on at least one side of the dough piece, the surfaces stick to each other thereby preventing loosening of the rolled-up dough. Additionally, the position of the croissant dough piece is adjusted to align the line from the top to the center of the base of the triangle of the dough piece with the moving direction of the upper flight of the endless belt device above which the rolling up device is provided when the dough piece is transferred from the pair of the rollers to the endless belt device via the transfer rollers, the base of the triangle of the dough piece is positioned perpendicular to the moving direction, and irregular rolls caused by slant positioning are completely prevented. Therefore, the losses caused by errors in the automatic rolling up of the dough piece are eliminated, thus preventing loosening and irregular rolls.

Claims: An apparatus for rolling adhesive dough pieces comprising; a pair of vertically juxtaposed rollers (5,7) for feeding dough pieces (4) therebetween, spaced apart from each other by a distance less than the thickness of the dough piece and moving in the same direction where they face each other, an endless belt device (9) positioned downstream of said pair of rollers (5,7), a dough piece rolling up device (11) positioned above the upper flight of said endless belt device (9), characterised in that two transfer rollers (13,15), each of a diameter significantly less than that of said pair of rollers (5,7) are positioned downstream thereof and are rotatable in the direction of the movement of the dough pieces (4), and in that each of said transfer rollers (13,15) is positioned in contact with or adjacent the peripheral surface of each of said pair of rollers (5,7), the peripheral speed of said transfer rollers (13,15) being faster than that of each of said pair of rollers (5,7), whereby, when the dough piece (4) is carried out of said pair of rollers (5,7), one of the surfaces of the dough piece (4) can selectively adhere to the surface of either of the pair of rollers (5,7) according to the adhesiveness of the respective dough piece surfaces, and then the leading tip of the dough piece can be peeled off from said selectively adhering roller surface by the relevant one of said transfer rollers (13,15).

Inventors: HAYASHI TORAHIKO, HAYASHI, TORAHIKO
Applicants: RHEON AUTOMATIC MACHINERY CO, RHEON AUTOMATIC MACHINERY CO. LTD.
Application year: 1987
Main classification: A21C3
IPC codes: A21C3