HK1067012B - A method and an apparatus for shaping a dough piece - Google Patents

Description

Apparatus for forming dough sheet

Technical Field

The present invention relates generally to a method and apparatus for stretching a mass of a strip of dough, such as bread dough, comprised of food items to form a dough sheet. More particularly, the present invention provides in a simple form an apparatus that can easily stretch a strip of bread dough to form a dough sheet.

Background

For example, attempts have been made to stretch a mass of a strip of dough consisting of food items, such as sponge dough, to form a dough sheet. Conventional stretching apparatus are disclosed in Japanese patent No.2860938 (Japanese laid-open publication No.10-075705) and Japanese patent publication No. 54-991.

In a conventional stretching apparatus, a mass of bread dough strips is conveyed on a conveyor belt. Above the conveyor belt, a planetary roller set comprising a series of rollers rolls like a wheel in its direction of movement. The planetary roller set is arranged so that only the front portion thereof, which is located just above the conveyor belt, travels in the direction of travel of the conveyor belt while forming a passage therebetween.

As the mass of the strip of bread dough on the conveyor is brought into the passage under the front portion of the planetary gear roller set, each roller of the front portion continuously rolls and stretches the mass of the strip of bread dough to form a sheet of bread dough.

Although the conventional stretching apparatus can successfully stretch the strip of bread dough to form a bread dough sheet, it requires a complicated structure including a series of rollers arranged like wheels.

Disclosure of Invention

It is therefore an object of the present invention to provide a novel stretching apparatus in a simplified form that can easily stretch a strip of dough to form a dough sheet.

It is another object of the present invention to provide a method of stretching a strip of dough to form a dough sheet in a simplified manner.

An apparatus for stretching and rolling a mass of a strip of food dough to form a dough sheet, the apparatus comprising:

a first conveying device for continuously conveying the strip of food dough at a first conveying speed in a direction of travel parallel to a length direction of the strip of food dough;

a primary elongated roller and at least one secondary elongated roller, the primary elongated roller and the at least one secondary elongated roller being perpendicular to the direction of travel and the at least one primary elongated roller and the at least one secondary elongated roller being opposed to each other in a manner that provides a gap therebetween for receiving the incoming strip of dough from the first conveyor; said gap including a path for conveying dough, said primary elongated roller and said secondary elongated roller rotating so as to convey the strip of dough out of said gap;

a first motor and a second motor for driving the primary elongated roller and the at least one secondary elongated roller in rotation, respectively;

a vibrating device for vibrating said primary elongated roller so that said primary elongated roller is opposed to said secondary elongated roller, the two elongated rollers being spaced apart from each other so that the strip of food dough introduced in the gap is stretched and rolled to form a dough sheet;

a third motor for driving the vibration device;

second conveying means located adjacent to the gap for receiving the dough sheet conveyed by the primary and secondary elongated rollers from the gap and conveying the dough thereon at a second conveying speed; and

a controller controls the rotational speeds of the first motor, the second motor, and the third motor based on the transport speed of the first transport device and the transport speed of the second transport device.

The present invention addresses the foregoing needs by providing a method for stretching and rolling a mass of a strip of food dough to form a dough sheet. The method comprises the following steps: providing at least one primary elongated roller and at least one secondary elongated roller, both of which are substantially perpendicular to the length direction of a mass of the strip of food dough and are opposed to each other in a manner that provides a gap therebetween for receiving the incoming strip of dough; and vibrating at least one of the primary elongated roller and the secondary elongated roller such that the at least one elongated roller is opposed to and spaced apart from the respective elongated roller such that the incoming mass of the strip of food dough in the gap is stretched and rolled to form a dough sheet.

The present invention also addresses the foregoing needs by providing an apparatus for stretching and rolling a mass of a strip of food dough to form a dough sheet. The apparatus includes a first conveyor for continuously conveying a strip of food dough thereon in a direction of travel that is substantially parallel to a length direction of the strip of food dough. At least one primary elongated roller and at least one secondary elongated roller substantially perpendicular to the direction of travel oppose each other in a manner that provides a gap therebetween for receiving the incoming mass of dough from the first conveyor. The vibrating device vibrates at least one of the primary elongated roller and the secondary elongated roller so that the at least one elongated roller is opposed to and spaced apart from the corresponding elongated roller so that the strip of food dough introduced in the gap is stretched and rolled into a dough sheet. A second conveying device receives the dough sheet from the gap and conveys the dough sheet thereon.

The primary elongated roller and the secondary elongated roller preferably rotate in the direction of travel of the incoming dough.

The primary elongated roller and the secondary elongated roller may be driven by separate motors, respectively, or may be driven by a common motor. The vibrating devices may be driven by separate motors or may be driven by a common motor.

The vibrating device may alternate between using a first gap and a second gap, where the difference in size between the first gap and the second gap is a minor difference.

In one aspect of the invention, the apparatus further comprises means for moving the incoming mass of the strip of food dough in the gap into at least one of the primary elongated roller and the secondary elongated roller in a manner such that the incoming dough slightly protrudes from and is slightly spaced from the at least one elongated rotating roller.

At least one of the primary elongated roller and the secondary elongated roller may include a plurality of planetary rollers, wherein each planetary roller rotates while moving along its orbit.

Additional features, advantages and objects of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, schematically illustrate preferred embodiments of the invention and, together with a general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.

Fig. 1A shows a schematic front view of the apparatus of the first embodiment of the present invention.

FIG. 1B shows a schematic side view of the rollers and conveyor of the apparatus of FIG. 1A.

Fig. 2A shows a schematic front view of an apparatus of a second embodiment of the invention.

FIG. 2B shows a schematic side view of the primary and secondary rollers and conveyor of the apparatus of FIG. 2A.

Fig. 3 shows a schematic front view of an apparatus according to a third embodiment of the invention.

Fig. 4A shows a schematic front view of an alternative secondary roller that can be substituted for the secondary rollers of the first, second, and third embodiments.

Fig. 4B shows a schematic side view of the rotating element of fig. 4A.

Fig. 5A shows a schematic front view of an apparatus according to a fourth embodiment of the invention.

Fig. 5B shows a schematic side view of the primary and secondary rollers and conveyor of the apparatus of fig. 5A.

Fig. 6A shows a schematic side view of an alternative primary roller that can be substituted for the primary roller of the fourth embodiment, wherein the alternative primary roller has a plurality of elongated planetary rollers along a substantially elliptical orbit.

Fig. 6B shows a schematic front view of the alternative secondary roller of fig. 6A.

Fig. 7A shows a schematic side view of another alternative primary roller that can be substituted for the primary roller of the fourth embodiment.

Fig. 7B shows a schematic front view of the secondary roller of fig. 7A.

Detailed Description

Description of the preferred embodiments

Referring now to the drawings, wherein like elements or similar functional elements are designated by like reference numerals, FIGS. 1A and 1B illustrate a first embodiment of the inventive tensioner 1A.

Although the elongated dough 9 is continuously supplied to the stretching apparatus 1A, a piece of the elongated dough 9 has been kneaded and prepared into, for example, bread dough in the preceding stage by a known processing apparatus (not shown) so as to form a dough strip.

Referring to fig. 1A, the stretching apparatus 1A of the present invention generally comprises a base 3, a pair of frames 5 and 7 fixedly mounted on the base 3, and a pair of opposing horizontal rollers located between the frames 5 and 7. The pair of opposing horizontal rollers includes an upper elongated roller (primary roller) 11 for applying a primary pressure to the upper surface of the elongated dough 9 and a lower elongated roller (secondary roller) 13 for applying a secondary pressure to the lower surface of the elongated dough 9.

The primary roller 11 and the secondary roller 13 are rotatably mounted on the respective rotating shafts 23 and 29 such that their rotating surfaces are spaced apart by a predetermined gap. The predetermined gap forms a passage for the dough 9 to be stretched and reduces its thickness. In this embodiment, the passage is a horizontal passage, but is not limited thereto.

As shown in fig. 1B, the apparatus 1A further comprises a first conveyor 15 and a second conveyor 17 (neither of which is shown in fig. 1A) from its upstream end to its downstream end, such that the opposing horizontal rollers 11 and 13 are located therebetween. The length direction of the rotary shafts 23 and 29 is perpendicular to the traveling direction of the first conveyor 15 and the second conveyor 17. The direction of rotation of the rollers 11 and 13 is along the direction of travel of the conveyors 15 and 17. In the embodiment of fig. 1B, the primary roller 11 rotates in a clockwise direction and the secondary roller 13 rotates in a counterclockwise direction in order to stretch and reduce the thickness of the incoming dough 9 by causing the incoming dough 9 to enter a passage smaller than the initial thickness of the incoming dough 9.

In this embodiment, the traveling speed of the first conveyor 15 is V1, and the traveling speed of the second conveyor 17 is V2, where V2> V1. In fig. 1A, although the elongated dough 9 is in the form of a dough strip on the first conveyor 15, which first conveyor 15 is located just before the rollers 11 and 13, the elongated dough 9 is in the form of a dough sheet on the second conveyor 17 because the elongated dough 9 is rolled, flattened, and stretched by the rollers 11 and 13.

Referring again to fig. 1A, both ends of the rotating shaft 23 of the primary roller 11 are rotatably supported by bearings 19 and 21, the bearings 19 and 21 being suspended from the frames 5 and 7. One end (at the bearing 19 side) of the rotating shaft 23 is connected to a first motor M1, which is mounted on the frame 5 through a bracket 24, M1. Thus, as described above, the rotary shaft 23 and the primary roller 11 are rotatably driven by the first motor M1 as described above. The first motor M1 is preferably a variable speed motor, such as a servo motor capable of variably controlling the rotational speed of the primary roller 11. In this case, the peripheral speed of the primary roller 11 can be controlled to be substantially the same as the traveling speed of the conveyors 15 and 17, thereby avoiding the occurrence of undesirable wrinkles or cracks in the traveling strip of dough 9 under the primary roller 11.

The secondary roller 13 may be swung so as to be opposed to and spaced apart from the primary roller 11.

In order to generate the oscillation of the secondary roller 13, an example of an arrangement is shown in fig. 1A. Both ends of the rotating shaft 29 of the secondary roller 13 are rotatably supported by the frames 5 and 7 through bearings 25 and 27. The rotary shaft 29 has a pair of elements, for example, eccentric bushes 31, at the ends of the secondary roller 13 so as to provide eccentric movement about the rotary shaft 29. The eccentric bush 31 supports the secondary roller 13 through a bearing 33. A balancer 30 is provided at an appropriate position on the rotation shaft 29 to stabilize the rotational movement thereof. The balancer 30 functions to cancel the swing inertia of the secondary roller 13 caused by the eccentric bushes 31. To achieve this function, a balancer 30 is mounted on the rotating shaft 29 so as to provide a phase inversion with respect to the phase of the eccentric bushes 31. One end (at the bearing 27 side) of the rotating shaft 29 is connected to a driven pulley 35. Below the driven pulley 35, the driving pulley 37 is connected to a second motor M2 mounted on the base 3. The second motor M2 is drivingly connected to the rotary shaft 29 by the drive pulley 37, the first endless belt 39 is wound around the pulleys 35 and 37, and the driven pulley 35. Further, a third motor M3 is connected to the drive pulley 41 and mounted on the base 3. The third motor M3 is drivingly connected to the secondary roller 13 through the drive pulley 41, and the second endless belt 43 is wound around the drive pulley 41 and the secondary roller 13.

The third motor M3 rotates the secondary roller 13 in the counterclockwise direction while the rotary shaft 29 rotates in this direction at a speed much higher than that of the secondary roller 13. Therefore, the secondary roller 13 can be made to frequently swing so that the secondary roller 13 is opposed to and spaced from the primary roller 11 during one rotation thereof.

The speed of the motors M1, M2 and M3 is controlled by a controller 50, which controller 50 may have a control panel (not shown) on the apparatus 1A, or be provided as a permanent controller (not shown) such as a personal computer. The controller 50 transmits the rotation speed of the shaft 23 connected to the motor M1 for driving the primary roller 11, the rotation speed of the shaft 29 connected to the motor M2, and the rotation speed of the secondary roller 13 driven by the motor M3.

Thus, the controller 50 gives the primary roller 11a rotation speed of R1 revolutions per minute, the shaft 29 a rotation speed of R2 revolutions per minute, and the secondary roller 13a rotation speed of R3 revolutions per minute. The rotational speeds R1, R2 and R3 may be determined according to the traveling speed V1 of the first conveyor 15, the traveling speed V2 of the second conveyor 17, the characteristics of the dough 9, or the desired thickness of the rolled dough 9 from the passage between the rollers 11 and 13, and so on.

For example, in order to prevent undesired slippage between the dough 9 and either of the rollers 11 or 13, the rotation speed R1 of the primary roller 11 and the rotation speed R2 of the secondary roller 13 may be determined in conjunction with any variation in the travel speed between the travel speed V1 of the first conveyor 15 and the travel speed V2 of the second conveyor 17 (where V2> V1). Alternatively, the rotation speed R1 of the primary roller 11 and the rotation speed R2 of the secondary roller 13 may be controlled to be the same as the traveling speed V2 of the second conveyor 17, or to be a midpoint speed between the traveling speed V1 of the first conveyor 15 and the traveling speed V2 of the second conveyor 17, depending on the characteristics of the dough 9 or the desired thickness of the rolled dough 9.

The function of the rollers 11 and 13 will now be described. The incoming dough 9 is fed from the first conveyor 15 into the path between the primary roller 11 and the secondary roller 13, on which first conveyor 15 the dough 9 is in the form of an elongated mass. The operation of flattening and forming the dough 9 into a sheet shape may then be performed by using the rollers 11 and 13. The primary roller 11 rolls and stretches the upper surface of the dough 9. Simultaneously, the secondary roller 13 rolls and stretches the lower surface of the dough 9, while the secondary roller 13 swings to be opposed to and spaced from the dough 9. Thus, the dough 9 passing through the passage between the rollers 11 and 13 is sheeted on the second conveyor 17 without any undesired wrinkling or breakage.

Since the secondary roller 13 swings to be opposed to and spaced from the dough 9, the dough 9 can be repeatedly pressed and pressed by the rollers 11 and 13. Thus, the dough 9 between the rollers 11 and 13 is more temporarily fluidized than before, so that it can be easily rolled, flattened, and stretched into a dough sheet by the rollers 11 and 13 without high pressure. This can produce a dough sheet having a predetermined thickness without an undesirable broken mesh structure of gel such as bread dough. Furthermore, since the rotational movement of the dough and the roller minimizes undesired sticking therebetween, the amount of the anti-sticking agent, which is generally formed into a powdery material, sprinkled on the dough can be reduced.

Although the oscillation of the secondary roller 13 may cause vibrations of the shaft 29, the balancer 30 controls those vibrations to be minimized to avoid violent vibrations.

In the first embodiment, the apparatus 1A uses a pair of rollers including one primary roller 11 and one secondary roller 13. More specifically, the primary roller 11 and the secondary roller 13 are an upper roller located on the upper surface of the incoming dough 9 and a lower roller vertically opposed to the upper roller to be adapted to the incoming dough 9 in the horizontal direction. It should be clear to a person skilled in the art that the present invention is not necessarily limited to such a design, but that it may be varied within the scope of the appended claims. For example, it can be changed as follows:

1) both the first horizontal conveyor 15 and the second horizontal conveyor 17 may be replaced with a vertical conveyor (not shown) so that the incoming dough 9 can be conveyed in the vertical direction. In this case, a pair of rollers in which one roller is opposed to the other roller in the horizontal direction may be used so as to be suitable for the characteristics of the incoming dough 9 in the vertical direction.

2) The first horizontal conveyor 15 may be replaced by a vertical conveyor (not shown) so that the incoming dough 9 is conveyed on the vertical conveyor and proceeds in the direction of the second horizontal conveyor 17. In this case, the pair of rollers 11 and 13 may be replaced with a pair of rollers in which the primary roller is opposed to the secondary roller in an oblique direction. The rollers arranged in the oblique direction may be provided at the turning point of the vertical conveyor and the second horizontal conveyor 17.

3) In the above alternative designs 1) and 2), one pair of rollers may be replaced with a plurality of pairs of rollers, for example, two pairs or three or more pairs of rollers.

4) In the above alternative designs 1), 2), and 3), the primary roller and the secondary roller may also be replaced with a set of cooperative rollers and a set of secondary rollers such that one set of rollers includes at least one roller and the other set includes a plurality of rollers which may have more or less rollers than the first set of rollers.

5) In the above alternative designs 1) to 4), the diameter of the primary roller (or the plurality of primary rollers) may be different from the diameter of the secondary roller (or the plurality of secondary rollers).

6) In the above alternative design 5), if the diameter of the primary roller (such as the upper roller) 11 or the plurality of primary rollers is larger than the diameter of the secondary roller (such as the lower roller) 13 or the plurality of secondary rollers, the area where each corresponding roller contacts the upper surface of the incoming dough 9 may extend further in the conveying direction of the incoming dough 9. Thus, the load of each secondary roller may be gradually applied to the upper surface of the incoming dough 9, thereby making the incoming dough 9 thicker.

7) As a combination of the above alternative designs 4) and 5), one secondary roller (such as a lower roller) 13 and a plurality of (such as three) primary rollers each having a diameter smaller than that of the secondary roller may be provided to obtain the same action as that of the alternative design 6). The plurality of primary rollers are arranged in a row in correspondence with a conveying direction of the first conveyor. In this row, the primary roller at the downstream end is preferably offset so as to be in closer contact with the upper surface of the incoming dough 9 than the primary roller at the upstream end.

Fig. 2B shows a stretching apparatus 1B of a second embodiment of the present invention. In the second embodiment, the third motor M3 (see fig. 1A) for rotating the secondary roller 13 in the first embodiment is omitted in order to simplify the structure of the stretching apparatus 1B. Instead of the third motor M3, the second motor M2 that rotates the rotary shaft 29 in the first embodiment as described above also rotates the secondary roller 13.

To achieve this, the second motor M2 has an elongated output shaft 40. The extended output shaft 40 is connected to a drive pulley 37a, which drive pulley 37a has a larger diameter than the drive pulley 37 (shown in fig. 1A) in the first embodiment. The extended output shaft 40 of the second motor M2 is also connected to a drive pulley 41, which drive pulley 41 is connected to the third motor M3 in the first embodiment.

As in the first embodiment, a first endless belt 39 is attached around the driven pulley 35 and the drive pulley 37 a. However, in the second embodiment, since the drive pulley 37a has a larger diameter, the drive pulley 37a and the first endless belt 39 form the transmission 45 between the driven pulley 35 and the drive pulley 37 a.

Then, only the second motor M2 can drive the secondary roller 13 and the rotary shaft 29 to rotate.

The drive pulley 37a is preferably a triangular pulley providing the transmission 45 so that the ratio between the rotational speeds of the secondary roller 13 and the rotary shaft 29 can be changed without limitation.

Since only two motors M1 and M2 are required, the structure of the stretching apparatus 1B can be more simplified.

Or the stretching apparatus 1B of the second embodiment can be further simplified to a form in which the first motor M1 is omitted by connecting the primary roller 11 and the secondary roller 13 by a suitable conveying means.

Fig. 2B shows an example of the transport means in the form of a gear mechanism 47. In the gear mechanism 47, an upper gear 11G and a lower gear 13G are connected to the primary roller 11 and the secondary roller 13 (neither roller is shown in fig. 2B). The upper gear 11G is firmly engaged with the first intermediate gear 49, while the lower gear 13G is firmly engaged with the second intermediate gear 51, said second intermediate gear 51 being firmly engaged with the first intermediate gear 49. The upper gear 11G has a centered pivot pin 53A and the first intermediate gear 49 has a centered pivot pin 53B, which centered pivot pin 53B is pivotally connected to the centered pivot pin 53A by a first connecting arm 55. Likewise, the lower gear 13G has a centered pivot pin 53C, while the second intermediate gear 51 has a centered pivot pin 53D, said centered pivot pin 53D being pivotally connected to the centered pivot pin 53C by a second link arm 57. Also, the centered pivot pin 53B of the first intermediate gear 49 is pivotally connected to the centered pivot pin 53D of the second intermediate gear 51 by a first connecting arm 59.

With the gear mechanism 47, the rotation of the secondary roller 13 by the second motor M2 can be transmitted to the primary roller 11 through the lower gear 13G, the second intermediate gear 51, the first intermediate gear 49, and the upper gear 11G. Therefore, the first motor M1 for rotating the primary roller 11 may be omitted.

By providing a design in which the diameter of the upper gear 11G is the same as the diameter of the lower gear 13G, and the diameter of the first intermediate gear 49 is the same as the diameter of the second intermediate gear 51, the rotational speed of the primary roller 11 can be made the same as the rotational speed of the secondary roller 13. In contrast, the rotation speed of the primary roller 11 may be different from that of the secondary roller 13 in relation to the different diameters of the gears.

Alternatively, another transport device than the gear mechanism 47 is also conceivable. As one example of a simplified conveying facility, an endless belt (not shown) twisted in a "8" shape may be wound around the primary roller 11 and the secondary roller 13.

In the second embodiment, the arrangement of the rollers 11 and 13 and the conveyors 15 and 17 may be changed to the same arrangement as those listed in 1) to 7) in the above-described first embodiment.

Referring now to fig. 3, there is shown in fig. 3a stretching apparatus 1C of a third embodiment of the present invention, in which the gap between the primary roller 11 and the secondary roller 13 is adjustable so as to control the thickness of the incoming dough 9. In the same manner as in the first and second embodiments, the incoming dough 9 passes through the passage between the primary roller 11 and the secondary roller 13 of the apparatus 1C just downstream of the first conveyor 15. From this point, the thickness of the incoming dough 9 can be controlled.

In the first embodiment, as shown in fig. 1A, the bearings 19 and 21 at both ends of the rotary shaft 23 of the primary roller 11 are directly suspended from the frames 5 and 7. In contrast, the bearings 19 and 21 of the third embodiment are mounted on bearing blocks 59A and 59B, the upper ends of which bearing blocks 59A and 59B have nuts 61A and 61B. The nuts 61A and 61B are adjustably fixed to stud bolts 63A and 63B vertically suspended from the frames 5 and 7. Depending on the fixing positions of the nuts 61A and 61B with respect to the stud bolts 63A and 63B, the horizontal plane of the rotating shaft 23 and the upper roller are adjustable, and thus the gap between the primary roller 11 and the secondary roller 13 is adjustable. The thickness of the incoming dough 9 can be controlled by adjusting the gap between the primary roller 11 and the secondary roller 13.

Since the rotary shaft 23 of the primary roller 11 is supported at two positions (at both ends thereof), it is necessary to avoid any uneven fixing between the nuts 61A and 61B and the stud bolts 63A and 63B. To achieve such an objective and to uniformly rotate the two nuts 61A and 61B in a harmonious manner, the nuts 61A and 61B are preferably fitted with sprockets 65A and 65B. Also, the endless chain 67 is wound around the sprockets 65A and 65B so that they rotate in unison in the same direction. Therefore, the levels of the bearing blocks 59A and 59B and the levels of both ends of the rotating shaft 23 can be adjusted in synchronization. Thus, a desired gap between the primary roller 11 and the secondary roller 13 can be obtained to facilitate thickness control of the incoming dough 9.

The sprockets 65A, 65B and the endless chain 67 may be replaced by other suitable means that enable the two nuts to rotate uniformly in a harmonic manner.

In the third embodiment, the gap between the primary roller 11 and the secondary roller 13 is adjusted by adjusting the level of the rotating shaft 23 of the primary roller 11. Alternatively, either the height of the rotary shaft 23 of the primary roller 11 or the height of the rotary shaft 29 of the secondary roller 13 (or both) may be adjustable. The level of the rotary shaft 29 of the secondary roller 13 can be adjusted by providing the same arrangement as the rotary shaft 23 as described above and as shown in fig. 3.

In the third embodiment, the arrangement of the rollers 11 and 13 and the conveyors 15 and 17 may be changed to the same arrangement as those listed in 1) to 7) in the above-described first embodiment.

Fig. 4A and 4B show an alternative secondary roller 13A that can replace the lower roller (or secondary roller) 13 of the first, second, and third embodiments. Fig. 4A and 4B are schematic and not to scale. The roller 13A may be made to swing so as to be opposed to or spaced from the primary roller (or the upper roller) 11. The secondary roller 13A, which is rotated by a motor (not shown), is rotatably supported by the bracket 69. The bracket 69 is vertically and slidably mounted on a guide post 73, the guide post 73 being attached to a fixed element (e.g., frame) 71 by a slidable element such as a ball bushing 75. The bracket 69 has a slit 77, the slit 77 being parallel to the longitudinal center axis of the roller 13A. The slot 77 receives a pin 81 of a rotating element 79, said rotating element 79 rotating about its rotation axis P under the action of a motor (not shown). The rotating member 79 also has a balance weight 79W to balance the secondary roller 13A with the bracket 69 and the like.

When the rotating member 79 rotates about its rotation axis P, the pin 81 rotates and thus moves along the slit 77 so as to cause vertical vibration of the bracket 69. Although the vertically vibrating bracket 69 is schematic (as shown in fig. 4A), its vertical vibration range is several millimeters in practice.

As shown in fig. 4B, the pin 81 preferably extends from a nut 85 on a radial stud 83 on the rotating member 79. In this way, the radial length between the pin 81 and the rotation axis P can be changed by adjusting the position of the nut 85 on the radial stud 83. This allows the range of vibration of the secondary roller 13A to be adjusted depending on the characteristics of the dough 9 or the desired thickness of the rolled dough.

Fig. 5A and 5B show a stretching apparatus 1D of a fourth embodiment of the present invention, in which a replacement primary roller (or upper roller) 11A is used in place of the primary roller 11 of the first embodiment.

As shown in fig. 5A and 5B, some components are denoted by the same reference numerals as in the first embodiment, thereby indicating that the arrangement and function thereof are the same as those of the first embodiment.

The rotary shaft 23 of the primary roller 11A and its related mechanism are the same as those of the primary roller 11 of the first embodiment, and are denoted by the same reference numerals as in the first embodiment.

The primary roller 11A includes a pair of circular disks 11P defining both ends of the primary roller 11A and a plurality of planetary rollers 11R substantially parallel to the rotation shaft 23 between the circular disks 11P. Each planetary roller 11R is rotatably supported by the disc 11P such that the planetary rollers 11R are arranged at even intervals along the circumference around the rotation shaft 23. That is, the rotating surface of the primary roller 11A forms a track of the planetary rollers 11R. Therefore, when the first motor M1 and its associated components rotate the rotational shaft clockwise (as indicated by R in fig. 5B), each planetary roller 11R rotates about the rotational shaft 23 in the traveling direction of the incoming dough 9. Each rotating planetary roller 11R also rotates on its own axis by contacting the upper surface of the incoming dough 9. This causes the incoming dough 9 to be stretched as well, reducing its thickness by passing it through the gap (between the planetary roller 11R and the secondary roller 13) which is smaller than the initial thickness of the incoming dough 9.

The primary roller 11A preferably includes suitable elements to assist or activate the rotation of the planetary rollers 11R. For example, as shown in fig. 5B, the primary roller 11A may be moved to one end thereof (at the left side in fig. 5B) with respect to the secondary roller 13 so as to provide a space to seat a member such as a belt 22 to activate the rotation of the planetary roller 11R. When one planetary roller 11R contacts the upper surface of the incoming dough 9, one end (at the left side in fig. 5B) of the planetary roller 11R also interferes with the belt 22 so as to activate the rotation thereof. This arrangement can reduce undesired slippage between the planetary roller 11R and the upper surface of the incoming dough 9. Therefore, the occurrence of undesirable wrinkling or cracking of the upper surface of the incoming dough 9 can be sufficiently avoided, and thus a desired shape of the incoming dough sheet can be produced.

As can be seen from a comparison between the primary roller 11A of the fourth embodiment and the primary roller 11 of the first embodiment, the primary roller 11A includes a plurality of planetary rollers 11R, and the primary roller 11 is constituted by only one roller. The primary roller 11A of the fourth embodiment thus has some features different from those of the primary roller 11 of the first embodiment, although the fourth embodiment has functions similar to those of the first embodiment.

Referring to fig. 5A, the function of the primary roller 11A will be described in detail. In the same manner as in the first embodiment, the secondary roller 13 is now rotated and rocked to be opposed to and spaced apart from the primary roller 11A. At this time, the primary roller 11A also rotates in the same manner as the primary roller 11 of the first embodiment. When one planetary roller 11R is disposed on an imaginary vertical axis (not shown) near the centers of the rotary shafts 23 and 29, the gap between the primary roller 11A and the secondary roller 13 is minimized. Then, the planetary roller 11R is gradually moved from the imaginary vertical axis toward the traveling direction of the incoming dough 9 by the rotation of the primary roller 11A. At this time, the secondary roller 13 swings to be gradually spaced from the primary roller 11A, the swing being caused by the swing of the secondary roller 13. The gap between the secondary roller 13 and the primary roller 11 (or one of the planetary rollers 11R that has just moved from the imaginary vertical axis) then increases slightly to be greater than the minimum gap. Thus, the gap between the primary roller 11A and the secondary roller 13 alternates between the minimum gap and the slightly increased gap to roll the incoming dough 9.

It is essential that the midpoints of the intervals between the adjacent planetary rollers 11R and the secondary roller 13 arranged on the imaginary vertical axis swing so as to gradually approach the primary roller 11A. This movement causes the incoming dough 9 to rise slightly between the primary roller 11A and the secondary roller 13 so as to form a slightly convex shape to the upper surface thereof to temporarily further fluidize it, so that the incoming dough 9 can be easily rolled, flattened, and stretched with the rollers 11A and 13.

Alternatively, by adjusting the swing range of the secondary roller 13, the upper surface of the incoming dough 9 between the primary roller 11A and the secondary roller 13 may alternate between a slightly convex shape (when its opposing surface has a slightly concave shape) and a slightly concave shape (when its opposing surface has a slightly convex shape).

Also, a mechanism for swinging the secondary roller 13 may be provided to the primary roller 11A instead of the secondary roller 13. With such an arrangement, when the primary roller 11A is swung to approach the secondary roller 13 so that the incoming dough 9 is slightly lowered, the upper surface of the incoming dough 9 has a slightly concave shape.

The primary roller 11A and the secondary roller 13 are interchangeable if desired.

The oscillation of the secondary roller 13 provides a stirring action to the incoming dough 9. Further, since the secondary roller 13 is rocked, the gap between the primary roller 11A and the secondary roller 13 and the intensity of the stirring action can be arbitrarily changed.

The rotation speed of the primary roller 11A and the amount of vibration of the secondary roller 13 may be changed according to the characteristics of the incoming dough 9 with respect to the conveying speed of the incoming dough 9.

The arrangement of the rollers and the conveyors 15 and 17 shown in fig. 5A may be changed to the same arrangement as those listed in 1) to 7) in the above-described first embodiment.

Fig. 6A and 6B show an alternative primary roller 11B having a plurality of elongated planetary rollers 95 in an elliptical orbit. The primary roller 11B includes a pair of endless chains 93 that are wound around the pair of end sprockets 91 arranged in the conveying direction. Both ends of each of the elongated planetary rollers 95 are rotatably supported by the endless chain 93 such that the elongated planetary rollers 95 are arranged at equal intervals.

A pair of guide members 97, such as guide rails, are preferably provided adjacent to both lateral sides of the conveyors 15 and 17 to guide and activate the rotation of the planetary rollers 95.

Obviously, the primary roller 11B (fig. 6A and 6B) has a longer track than the primary roller 11A (fig. 5A and 5B). This indicates that the former has a more extended range than the latter in terms of the force applied by the planetary rollers 95 to stretch and roll the dough 9. With such a longer track, two or more secondary rollers similar to the secondary roller 13 may be provided in a parallel manner. In this case, one or more auxiliary conveyors (not shown) may be provided between adjacent secondary rollers.

Although the orbit of the planetary rollers 95 is shown in the form of an elliptical orbit, the orbit may be a rectangular orbit, a triangular orbit, or the like. In either case, the planetary rollers 95, which are opposed to the secondary roller 13 and the conveyors 15 and 17, are preferably arranged such that their orbits are inclined downward from upstream to downstream.

Fig. 7A and 7B show another alternative primary roller 94. A pair of guide rails 90 (only one is shown in fig. 7B) are provided at the lateral sides of the passage of the incoming dough 9. Each rail 90 has an elongated groove that slidably receives a slide element 92, the grooves being opposite each other. The corresponding sliding member 92 rotatably supports each end of the primary roller 94. (although only one primary roller 94 is shown in fig. 7A and 7B, a plurality of such rollers are provided.) a pair of arms 96 (only one shown in fig. 7A and 7B) is provided for each primary roller 94. One end of each arm 96 is connected to the slide member 92 while the other end is drivingly connected to a reciprocating mechanism, such as a crank mechanism, so as to provide sliding movement of the slide member 92 within the elongated recess. A pair of guide members 98 (only one is shown in fig. 7B) similar to the guide members 51 in fig. 6A and 6B are provided near both lateral sides of the conveyors 15 and 17 so as to guide and activate the rotation of the primary roller 94.

When the reciprocating mechanism causes the sliding element 92 to reciprocate in the guide rail 90 in the conveying direction of the dough 9, the primary roller is actively rotated in the conveying direction of the dough 9 by contacting the guide member 98. Therefore, the active rotation of the primary roller 94 in the conveying direction of the dough 9 cooperates with the vibrating and rotating motion of the secondary roller 13 to assist the stretching and rolling of the dough 9.

While the invention has been shown in several forms, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the appended claims.

Claims (1)

1. An apparatus for stretching and rolling a mass of a strip of food dough to form a dough sheet, the apparatus comprising:

a first conveying device for continuously conveying the strip of food dough at a first conveying speed in a direction of travel parallel to a length direction of the strip of food dough;

a primary elongated roller and at least one secondary elongated roller, the primary elongated roller and the at least one secondary elongated roller being perpendicular to the direction of travel and the at least one primary elongated roller and the at least one secondary elongated roller being opposed to each other in a manner that provides a gap therebetween for receiving the incoming strip of dough from the first conveyor; said gap including a path for conveying dough, said primary elongated roller and said secondary elongated roller rotating so as to convey the strip of dough out of said gap;

a first motor (M1) and a second motor (M2) that respectively drive the primary elongated roller and the at least one secondary elongated roller in rotation;

a vibrating device for vibrating said primary elongated roller so that said primary elongated roller is opposed to said secondary elongated roller, the two elongated rollers being spaced apart from each other so that the strip of food dough introduced in the gap is stretched and rolled to form a dough sheet;

a third motor (M3) for driving the vibration device;

second conveying means located adjacent to the gap for receiving the dough sheet conveyed by the primary and secondary elongated rollers from the gap and conveying the dough thereon at a second conveying speed; and

a controller (50) controls the rotation speeds of the first motor (M1), the second motor (M2), and the third motor (M3) in accordance with the conveyance speed of the first conveyance device and the conveyance speed of the second conveyance device.