Abstract:
An apparatus for bending a bar-like dough piece into substantially an M-shaped piece is disclosed. A conveying section ( 2 ) continuously conveys bar-like dough pieces ( 1 ) in a traveling direction that is orthogonal to the length of the bar-like dough piece ( 1 ). Each incoming bar-like dough piece ( 1 ), whose length is measured by photosensors ( 38 ), is centered by a centering device in a centering section ( 3 ) based on the measured length of it. A forming section ( 4 ) bends the centered bar-like dough piece ( 1 ) with a centrally located bending member and two bending members symmetrically located with respect to the center of the length of the bar-like dough piece. Because the symmetrically located bending members are oriented inversely with respect to the centrally located bending member, the bar-like dough piece ( 1 ) is formed into an M-shaped piece. The bending members are varied depending on the length of the bar-like dough piece, and the distances of the movement, in said traveling direction, of the bending members are adjustable.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to a method and an apparatus for shaping a dough piece, and in particular to a method and an apparatus for shaping a bar-like dough piece into a bent one.  
         BACKGROUND OF THE INVENTION  
         [0002]    It has been proposed to use a bending machine to modify a bar-like bread dough piece into a bent, e.g., an M-shaped, one.  
           [0003]    Examples of the conventional bending machines are disclosed in Japanese Patent Early-Publications Nos. 48-96779 (Itoh) and 5-316923 (Yamazaki et al.), and Japanese Utility Model Early-Publication No. 48-31292 (Kuroha).  
           [0004]    Itoh discloses a bending machine to modify a bar-like bread dough piece into an M-shaped one. The machine includes a conveyor for conveying the bar-like piece along a direction that is orthogonal to the length of the bar-like piece, and a bending mechanism located at the end of the conveyor. The bending mechanism includes a stopper for stopping the progress of the center portion of the bar-like piece on the conveyor, and a pair of brakes for stopping the progress of both ends of the bar-like piece. Above the conveyor, the bending mechanism also includes a pair of ratchet wheels, which has teeth for pushing the portions to be bent, which wheels are located between the center portion and both ends of the bar-like piece. The ratchet wheels rotate around a rotary shaft that extends the length of the bar-like piece in such a way that the teeth of the ratchet wheels contact and push the corresponding positions of the bar-like piece on the conveyor in the traveling direction. When the teeth of the ratchet wheels push the bent portions of the bar-like piece on the conveyor in the traveling direction, the center portion of the bar-like piece is stopped by the stopper and both ends of it are stopped by the brakes. Therefore, the incoming bar-like piece on the conveyor is formed into an M-shaped one by the bending mechanism.  
           [0005]    This forming process, however, is unreliable, since each tooth of the ratchet wheels supports the corresponding bent portion of the bar-like piece only by point contact. Further, the rotary teeth of the ratchet wheels tend to scratch the M-shaped piece.  
           [0006]    To remove these problems involved in the ratchet wheels, Yamazaki proposed to replace the ratchet wheels in Itoh with a pair of pivotaling rods, which extend in the direction of the thickness of the bar-like piece on the conveyor. In that process, the pivoting rods fall on the relevant positions of the bar-like piece in such a way that each pivoting rod supports the bar-like piece through a line contact. Once the bar-like piece has been formed into an M-shaped one, the pivoting rods pivot away from the M-shaped piece opposite the direction the conveyor is travelling.  
           [0007]    Besides what Yamazaki has proposed, Kuroha proposed a movable damper which moves on the conveyor faster than does the conveyor, instead of the ratchet wheels of Itoh. Kuroha also proposed a detector for detecting the position of the dough on the conveyor to control the movable damper based on the signal from the detector.  
           [0008]    Unfortunately, Yamazaki and Kuroha have difficulty in producing a symmetrical and well-balanced M-shaped piece. In particular, if the continuously fed bar-like pieces include undesired varying sizes, this difficulty increases. Thus, bread products that have been fermented and baked have a non-uniform shape.  
           [0009]    Therefore, it is advantageous to provide an apparatus and a method to accurately change a bar-like dough piece into a bent and shaped one.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention addresses the aforementioned problems by providing an apparatus for bending a bar-like dough piece extended along its length into a predetermined form. The apparatus comprises conveying means for continuously conveying bar-like dough pieces thereon in a traveling direction that is orthogonal to the length of each bar-like dough piece; bending means for bending each incoming bar-like dough piece symmetrically or asymmetrically with respect to the center of the length of the incoming bar-like dough piece; and replacing means for replacing at least one of the relationships of the relative dispositions in the length of the bar-like dough piece of the bending means and the incoming bar-like dough piece with a predetermined relationship of a disposition relative to them.  
           [0011]    In one aspect of this invention, the predetermined relationship is determined so that the bending means bends the bar-like dough piece with a load substantially centrally located in the length of the bar-like dough piece. If this bar-like dough piece is to be further bent symmetrically with respect to the center of it, the predetermined relationship may also be determined so that the bending means bends the bar-like dough piece with loads substantially symmetrically located respect to the center of the bar-like dough piece, wherein the substantially symmetrically located loads are orientated inversely with respect to the substantially centrally located load. The resulting bent dough piece takes, e.g., an M-shape.  
           [0012]    In another aspect of the invention, the predetermined relative position is determined so that the bending means bends said bar-like dough piece with an off-center load in respect to the center of the length of said bar-like dough piece. If this bar-like dough piece is to be further bent asymmetrically with respect to the center of it, the predetermined relative position may also be determined so that the bending means bends said bar-like dough piece with loads asymmetrically located with respect to the center of the length of said bar-like dough piece, wherein the asymmetrically located loads are orientated inversely with respect to said substantially centrally located load. The resulting bent dough piece takes, e.g., substantially an M-shape.  
           [0013]    The present invention also provides an apparatus for bending a bar-like dough piece extended in its length into a predetermined form. The apparatus comprises conveying means for continuously conveying bar-like dough pieces thereon in a traveling direction that is orthogonal to the length of the bar-like dough piece; a first pushing means for pushing the bar-like dough piece on a first position that is located in said length of said bar-like dough piece; a first aligning means for aligning said first position of the dough piece with the first pushing means; a second pushing means for pushing the bar-like dough piece on the second of two positions that are located on said length of the bar-like dough piece, wherein the forces of said second pushing means to be applied to the second of two positions of the bar-like dough piece are orientated inversely with respect to the force of said first pushing means to be applied to the first position; and a second aligning means for aligning the second positions of said dough piece with the second pushing means.  
           [0014]    The apparatus preferably comprises means for temporarily holding the conveyed bar-like dough piece and means for detecting both ends of the length of the temporarily held bar-like dough piece. The first aligning means may align both detected ends at predetermined positions. They correspond to imaginary ends of both ends of the bar-like dough piece. The first position can be either substantially positioned centrally or off-center on the bar-like dough piece.  
           [0015]    The apparatus may also comprise means for measuring the length of the bar-like dough piece based on both said detected ends. To more appropriately control the bending process, the apparatus preferably comprises means for determining the degree of the pushing with the second pushing means against the second positions of the dough piece based on the measured length of the bar-like dough piece, and means for controlling the actual degree to be pushed with the second pushing means against the second position of the dough piece based on said determined degree. The measured length of the bar-like dough piece can also be used for an alternative alignment of the first aligning means so that the first position is either substantially positioned centrally or off-center on the bar-like dough piece.  
           [0016]    The present invention also provides a method for bending a bar-like dough piece having a length into a predetermined form. The method comprises the steps of:  
           [0017]    (a) continuously conveying bar-like dough pieces in a traveling direction that is orthogonal to the length of each said bar-like dough pieces;  
           [0018]    (b) determining a plurality of actual positions from which each said bar-like dough piece is to be bent on the length of said bar-like dough piece;  
           [0019]    (c) substituting said determined actual positions with predetermined positions; and  
           [0020]    bending each incoming bar-like dough piece at said predetermined positions symmetrically or asymmetrically with respect to the center of said length of said incoming bar-like dough piece.  
           [0021]    Additional features, advantages, and objectives of this invention will be set forth in the description which follows and in part will be apparent from it, or may be learned by practicing the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]    The accompanying drawings, which are incorporated in and constitute a part of the specification, schematically illustrate a preferred embodiment of the present invention, and together with the general description given above and the detailed description of the preferred embodiment given below serve to explain the principles of the invention.  
         [0023]    [0023]FIG. 1 shows a schematic plane view of the apparatus of the first embodiment of the present invention.  
         [0024]    [0024]FIG. 2 shows a schematic side view of the apparatus of FIG. 1.  
         [0025]    [0025]FIG. 3 shows a detailed plane view of a forming section of the apparatus of FIG. 1.  
         [0026]    [0026]FIG. 4 shows a second motor and its transmission under a first base of FIG. 1, the first base being removed.  
         [0027]    FIGS.  5 A- 5 E show the steps of forming a bar-like dough piece into an M-shaped dough piece with the forming section in the first embodiment.  
         [0028]    FIGS.  6 A- 6 E show the steps of modifying a bar-like dough piece into an M shaped dough piece with the alternative forming section in the alternative embodiment. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0029]    Turning now to the drawings, wherein the same elements or similar functional elements are designated by like reference numerals, FIGS.  1 - 5  show the first embodiment of a bending machine of the present invention adapted to produce M-shaped bread dough pieces.  
         [0030]    Although a plurality of bread dough pieces  1  are continuously fed to the machine, each dough piece  1  has been formed into a bar-like form in the preceding step with a known forming machine (not shown).  
         [0031]    In reference to FIGS. 1 and 2, the bending machine of the invention generally comprises, from its upstream end to its downstream end, a conveying section  2  for continuously conveying a plurality of bar-like dough pieces  1 , a centering section  3  for centering each incoming bar-like dough piece  1 , a forming section  4  for forming the centered piece  1  into an M-shaped piece, and a product receptacle  5 , which communicates with a product holder  53 . The product holder  53  receives a predetermined number of M-shaped pieces arranged in a row and holds them during the following process or processes. As in this embodiment, if the bar-like dough pieces  1  are bread dough pieces, the following process, in which the holder  53  holds the dough pieces, includes fermentation and baking steps.  
         [0032]    The machine also includes a controller  6  for controlling the bending of the pieces  1 .  
         [0033]    The conveying section  2  includes a first conveyor  21  for receiving bar-like pieces  1  that are continuously fed from the preceding station and for conveying them in a traveling direction designated by an arrow in such a way that the length of each bar-like piece  1  is aligned orthogonally to the traveling direction. The conveying section  2  also includes a second conveyor  22 , which runs from adjacent the leading end of the first conveyor  21 , for receiving the incoming bar-like piece  1  from it, and a mesh  23 , located above the second conveyor  22 , for further forming the incoming bar-like piece  1  on the second conveyor  22  into a more accurate and bar-like form. The traveling direction of the second conveyor  22  is the same as the traveling direction of the first conveyor  21 , as designated by an arrow.  
         [0034]    The centering section  3  has a pair of centering plates  31   a,    31   b  for temporarily holding the incoming bar-like piece  1 . The centering plates  31   a,    31   b  are positioned adjacent the leading end of the second conveyor  22  and are arranged together substantially to form a V-shape in a vertical cross-section. But the lower ends of them are spaced apart from each other. The centering plate  31   b,  whose upper end is pivotally mounted on a rotatable shaft  32 , is pivotally rotated around it. The rotatable shaft  32  is rotatably supported on a movable base  33 , which is movably mounted on rails  35  that are supported on a frame  34  of the second conveyor  22 . The rails  35  and the movable base  33  are moved orthogonally to the traveling direction of the second conveyor  22 . Hereinafter, the direction in which the movable base  33  moves is referred to as the “direction of the width.” 
         [0035]    The movable base  33  is provided with a rack  36   a  that is engaged with a pinion  36   b.  The pinion  36   b  is rotatably mounted on a shaft of a motor  37 , which is mounted on the frame  34 . When the motor  37  rotates, the movable base  33 , and thus the centering plates  31   a,    31   b,  move in the direction of the width. On the outer sides of the pair of the centering plates  31   a,    31   b  in the direction of the width, detectors, typically photosensors  38 , are provided for detecting the positions of both ends of the incoming bar-like dough  1  at the centering plates. The photosensors  38  provide the detecting signals to the controller  6 .  
         [0036]    As shown in FIG. 3, the forming section  4  includes a pair of pushing plates  40   a  and  40   b  and their first and second driving mechanisms, and a third conveyor  42   a,  which runs from adjacent the leading end of the second conveyor  22 , for receiving the incoming bar-like piece  1  from it. The third conveyor  42   a  includes an endless belt  42   b  running around a pair of pulleys  42   c  (FIG. 2).  
         [0037]    The traveling direction of the third conveyor  42   a  is the same as the traveling direction of the second conveyor  22 . Planes on which the bar-like pieces  1  are located of the first, second, and third conveyors  21 ,  22 , and  42   a  are located in substantially the same plane. In FIG. 3, the traveling direction of the third conveyor  42   a  is shown in the X direction, the direction of the width is shown in the Y direction, and the Z direction (the vertical direction) is shown orthogonally to the X and Y directions.  
         [0038]    Each pushing plate  40   a  and  40   b  is supported on the corresponding support bases  41   a  and  41   b.  The support bases  41   a  and  41   b  are slidably mounted on first bases  43   a  and  43   b  via first linear-bearings  45   a  and  45   b  thereon in such a way that that they can slidably move to and from the second conveyor  22  in the X direction. In turn, the first bases  43   a  and  43   b  are slidably mounted on a second base  44  via a pair of second linear-bearings  45   b  thereon in such a way that the first bases  43   a  and  43   b,  and thus the pushing plates  40   a,    40   b,  can slidably reciprocate in the Y direction as indicated by arrows Y. The pushing plates  40   a  and  40   b  also reciprocate in a direction indicated by an arrow S 1  and a direction indicated by an arrow S 2 , respectively. The S 1  and S 2  directions are arranged so that they substantially and symmetrically converge in the X direction.  
         [0039]    The reciprocating movements in the S 1  and S 2  directions of the first bases  43   a  and  43   b  are driven by a first motor  46 A through a first driving mechanism, as described below.  
         [0040]    In the first driving mechanism, a mechanical coupling  50  couples an output shaft  46   a  of the first motor  46 A to an input shaft  52   a  of a gearbox  52 , in which are journaled the input shaft  52   a  and an output shaft  52   b  in an orthogonal relation via a gear mechanism (not shown). That is, the output shaft  46   a  of the first motor  46 A and the input shaft  52   a  of the gearbox  52  extend in the Y direction, while the output shaft  52   b  of the gearbox  52  extended in the Z direction.  
         [0041]    The end of the output shaft  52   b  that is outside the gearbox is pivotally connected to one end of a first arm  54 . In turn, the other end of the first arm  54  is pivotally connected to one end of a second arm  56 . A T-shaped connecting member  58  is drivingly connected to the other end of the second arm  56  in a partly overlapped relation to the first bases  43   a  and  43   b  and therebetween. The T-shaped connecting member  58  is slidably mounted on a third linear-bearing  45   c,  which extends in the X direction in such a way that it can slidably move in the X direction. The third linear-bearing  45   c  is provided on a third base  43   c,  which is supported between the first bases  43   a  and  43   b  and above the second base  44 . The pushing plates  40   a  and  40   b  are pivotally connected to both ends of the T-shaped connecting member  58  via third arms  58   a  and  58   b,  respectively.  
         [0042]    When the motor  46 A rotates forward or backward, the first arm  54  and the second arm  56  are pivotally moved to cause the reciprocating movement of the T-shaped connecting member  58  in the X direction. The reciprocating movement of the T-shaped connecting member  58  in the X direction causes reciprocating movements of the pushing plates  40   a  and  40   b  in the directions indicated by arrows S.  
         [0043]    The second mechanism includes a second motor  46 B. As shown in FIG. 4, it is mounted on a mount  60  through which an output shaft  46   b  from it extends in the Y direction. The mount  60  also rotatably supports via a bearing  64  a threaded shaft  62 , which extends in the Y direction under the first bases  43   a  and  43   b.  The threaded shaft  62  is driven through a gear  68 , which meshes with the gear  66  driven by an output shaft  46   b  of the motor  46 B. The threaded shaft  62  extends thorough a nut  70   a  mounted under the first base  43   a  and a nut  70   b  mounted under the first base  43   b.  (While only one nut  70   a  is shown in FIG. 4 by a solid line, two nuts  70   a,    70   b  are shown in FIG. 3 in dotted lines.) The nut  70   a  can have a forwardly threaded hole (not shown) and the nut  70   b  can have a reversely threaded hole (not shown), and vice versa. Therefore, the portions  62   a  of the threaded shaft  62  that mesh with the thread holes of the nuts  70   a  and  70   b  are forwardly threaded and reversely threaded (only one portion  62   a  of the threaded shaft  62  is shown in FIG. 4). When the second motor  46 B rotates, the threaded shaft  62  also rotates, to increase or decrease the distance between the first bases  43   a  and  43   b  based on the direction of the rotation of the second motor  46 B. The pushing plates  40   a  and  40   b  on the first bases  43   a  and  43   b  thus move in the Y direction.  
         [0044]    Provided between the centering section  3  and the third conveyor  42   a  of the forming section  4  is a stopper  47 , which has a bar  47   a  that is pivotally mounted on a rotary shaft  47   b,  which extends in the Y direction. The bar  47   a  is selectably positioned between a position where it engages and stops the piece  1  and a position where it disengages a piece  1 , based on the positions of the rotation of the rotary shaft  47   b.  When the bar  47   a  contacts and stops the incoming piece  1 , it bends it, since it applies a load to the bar-like piece.  
         [0045]    Note that the force of the bar  47   a  to be applied to the first position of the bar-like piece  1  is orientated inversely with respect to the forces of the pushing plates  40 A and  40 B, which forces are to be applied to the second positions in order to form the bar-like piece  1  into an M-shaped one.  
         [0046]    On the belt  42   b  of the third conveyor  42   a,  a pair of first vertical conveyor belts  48 A,  48 B is provided downstream of the stopper  47  in such a manner that the planes of them are orthogonal to the plane of the belt  42   b  of the third conveyor  42   a.  The pair of first vertical conveyor belts  48 A is also arranged to define a funnel-shaped passage between them, as viewed from above the plane of the third conveyor  42   a.  The funnel-shaped passage of the first vertical conveyors belts  48 A includes, in the conveying direction, a receiving space  48   a  for receiving and gripping a piece  1 , which is subject to be formed into an M-shape in a manner described below, between the pair of the first vertical conveyors belts  48 A, and a narrow passage  48   b  for conveying the piece  1  that has been formed into an M-shape.  
         [0047]    The forming section  4  also includes a fourth conveyor  42   d,  which runs under the leading end of and adjacent the third conveyor  42   a,  for receiving the piece  1  that has been formed into the M-shape. The fourth conveyor  42   d  includes an endless belt  42   e  entrained around a pair of pulleys  42   f  (FIG. 2). The traveling direction of the fourth conveyor  42   d  is the same as the traveling direction of the third conveyor  42   a.    
         [0048]    On the belt  42   e  of the fourth conveyor  42   d,  a pair of second vertical conveyor belts  48 B is provided in such a manner that the planes of them are orthogonal to the plane of the belt  42  of the fourth conveyor  42   d.  Similarly to the first vertical conveyor belts  48 A, the second vertical conveyors belts  48 B are also arranged to define a funnel-shaped passage between them, as viewed from above the belt  42   e  of the fourth conveyor  42   d.  The funnel-shaped passage of the second vertical conveyor belts  48 B receives the incoming M-shaped piece from the third conveyor  42 A and discharges it to the product receptacle  5 .  
         [0049]    As shown in FIG. 2, the product receptacle is provided with a storage chamber  51  for temporarily storing a plurality of M-shaped pieces  1 . The storage chamber  51  has a bottom opening  52  and a shutter (not shown). It opens and closes the opening  52 . Under the bottom opening  52 , the product holder  53  is movably placed.  
         [0050]    Now the operation of the bending machine will be explained.  
         [0051]    As shown in FIG. 1, the bar-like pieces  1  are continuously fed into the conveying section  2  by the first conveyor  21 . Then the bar-like pieces  1  are carried forward on the second conveyor  22 , while they are formed into a more regular bar-like form with the mesh  23 . The bar-like pieces  1  are then fed to the centering section  3  in such a way that the lengths of them are substantially orthogonal to the X direction. In other words, the lengths of the bar-like pieces  1  are extended in the Y direction.  
         [0052]    The incoming bar-like piece  1  on the centering section is then dropped into the passage between the centering plates  31   a  and  31   b  and held therebetween. At this time, the photosensors  38  detect the positions of both ends of the incoming bar-like piece  1 , which is gripped between the centering plates  31   a  and  31   b,  and thus provide the detecting signal to the controller  6 .  
         [0053]    The controller  6  compares the positions detected by the photosensors  38  with the predetermined reference positions for both ends of the bar-like piece  1  that is gripped between the centering plates  31   a  and  31   b.  As the result of this comparison, the controller  6  moves the movable base  33  and thus the centering plates  31   a  and  31   b  so as to reposition the actual positions of both ends of the bar-like piece  1  to the predetermined reference positions. Thus, the bar-like piece  1  that is gripped between the centering plates  31   a  and  31   b  is centered. In this embodiment, the center of the bar-like piece  1  is in its right position. Then the rotary shaft  32  is rotated to open the opening that is formed by the lower ends of the centering plates  31   a,    31   b.  The bar-like piece  1  then drops onto the third conveyor  42   a  of the forming section  4 .  
         [0054]    In reference now to FIGS. 5A to  5 E, the processes for forming the dropped bar-like piece  1  on the third conveyor  42   a  into on M-shaped piece are described.  
         [0055]    The pushing plates  40   a,    40   b  move downstream to push the second positions of the bar-like piece  1 , while the bar  47   a  of the stopper  47  engages the first position of the bar-like piece  1  and stops its movement (FIG. 5A).  
         [0056]    These cooperative actions of the pushing plates  40   a,    40   b  and the stopper  47  start modifying the bar-like piece  1  into an M-shaped piece. In this step, the stopper  47  bends the bar-like piece  1  with a substantially centrally located load, while the pushing plates  40   a,    40   b  bend the bar-like piece  1  with substantially symmetrically located loads with respect to the center of the length of the bar-like piece  1  (FIG. 5B).  
         [0057]    As the pushing plates  40   a,    40   b  move further downstream to push the second positions of the piece  1 , the shape of the piece  1  becomes closer to an M-shape and the piece  1  becomes gripped between the receiving space  48   a  of the first vertical conveyor belts  48  (FIG. 5C).  
         [0058]    Once the bar-like piece  1  is formed into an M-shaped piece, the stopper  47  pivotally rotates away from the position shown in FIG. 5C to the second position, where the bar  47   a  is removed from the bar-like piece  1  (FIG. 5D).  
         [0059]    The M-shaped piece  1  then passes through the narrow passage  48   b  of the first vertical conveyor belts  48 A such that it becomes even closer to an M-shape (FIG. 5E).  
         [0060]    The controller  6  can measure the length of the bar-like piece  1  based on the signal from the photosensors  38  and thus can determine the appropriate second positions for the measured length of the bar-like piece  1 .  
         [0061]    The pushing plates  40   a,    40   b  can be moved onto in these appropriate second positions, since they can be moved in the Y direction. The degree of the pushing of the pushing plates  40   a,    40   b  against the piece  1  may be adjusted based on the length of the bar-like piece  1  such that a well balanced M-shaped piece may be produced.  
         [0062]    In reference again to FIG. 1, the piece  1  that has been formed into the M-shaped piece shown in FIG. 5E is then dropped onto the fourth conveyor  42   d  from the third conveyor  42   a.  The dropped M-shaped piece  1  then passes through the funnel-shaped passage between the second vertical conveyor belts  48 B to the product receptacle  5 , while its M-shaped form is maintained.  
         [0063]    Preferably the second vertical conveyors belts  48 B and thus its funnel-shaped passage can pivotally move in the width direction (as shown in dotted lines in FIG. 1) so that the continuously incoming M-shaped pieces  1  are shifted to the right or left side in the width direction. This action facilitates an arrangement for continuously feeding M-shaped pieces into the product holder  53 .  
         [0064]    Although the bar-like piece  1  in the above embodiment is formed into an M-shape, the bar-like piece  1  may be formed into a different shape, e.g., as N-shape.  
         [0065]    FIGS.  6 A- 6 E show a bending machine of the second embodiment of the invention to form the bar-like piece  1  into an N-shaped piece. With respect to the center of the piece  1 , the N-shaped piece is asymmetrical, whereas the M-shaped piece in the first embodiment is symmetrical. Therefore, in this embodiment, an alternative forming section for forming the bar-like piece  1  into an N-shaped piece is provided instead of the forming section  4  for the M-shaped piece of the first embodiment. The remaining sections of the bending machine of the second embodiment are the same as those in the first embodiment.  
         [0066]    As shown in FIG. 6A, in the alternative forming section, the bar  47   a  of the stopper is located at a first position that is off-center with respect to the center of the bar-like piece  1 . The pushing plates  40   a  and  40   b  are asymmetrically arranged at second positions that are asymmetrically positioned with respect to the center position of the bar-like piece  1 . Pushing plate  40   a  is arranged in the same way as that in the first embodiment. Pushing plate  40   b  is arranged such that it pushes one end of the bar-like piece  1  in the Y direction, and the pushing plate  40   b  is located at one end of the bar-like piece  1 .  
         [0067]    The pushing plates  40   a,    40   b  move downstream to push the bar-like piece  1  an the second positions, while the bar  47   a  of the stopper  47  stops the first position of the bar-like piece  1  and stops its movement (FIG. 6A).  
         [0068]    These cooperating actions of the pushing plates  40   a,    40   b  and the stopper  47  start to form the bar-like piece  1  into an N-shaped piece. In this step, the stopper  47  bends the bar-like piece  1  with an off-center load, while the pushing plates  40   a,    40   b  bend the bar-like piece  1  with loads asymmetrical with respect to the center of the length of the bar-like piece  1  (FIG. 6B).  
         [0069]    As the pushing plates  40   a,    40   b  move further downstream to push the second positions of the piece  1 , their shape becomes closer to an N-shaped piece, which is gripped between the receiving space  48   a  of the first vertical conveyor belts  48  (FIG. 6C).  
         [0070]    Once the bar-like piece  1  is formed into an N-shaped piece, the stopper  47  pivotally rotates away from the position shown in FIG. 6C to the second position, where the bar  47   a  in removed from the bar-like piece  47  (FIG. 6D).  
         [0071]    The N-shaped piece  1  then passes through the narrow passage  48   b  of the first vertical conveyor belts  48 A such that it is even closer to an N-shape (FIG. 6E).  
         [0072]    Also in the second embodiment, the controller  6  may move the pushing plates  40   a,    40   b  in the these appropriate second positions based on the signal from the photosensors (FIG. 1). The degree of the pushing of the pushing plates  40   a,    40   b  against the piece  1  may be adjusted based on the length of the bar-like piece  1  such that a well balanced N-shaped piece may be produced.  
         [0073]    Although the invention has been shown in several forms, it will be obvious to those skilled in the art that various changes and modifications can be made without departing from the sprit and scope of the appended claims.  
         [0074]    For example, in the above embodiments, the aligning of the first position with the bar  47   a  is performed to align both detected ends of the bar-like piece with the reference positions. Alternatively, the center of the length of the bar-like piece can be determined based on the length of the bar-like piece measured by the controller  6 . Thus, an alternative alignment of the first position with the bar  47   a  may be performed so as to align a reference position with the determined center position of the bar-like piece  1 . This alternative aligning is preferable if considerable variations in the lengths of the bar-like pieces exist. The reference position is at the center position of the bar-like piece  1  when the bar-like piece is to be formed into an M-shape. When the bar-like piece/is to be formed into an N-shape, the reference position is an off-center position of the bar-like piece  1 .  
         [0075]    Besides the bread dough piece in the embodiments, any other dough piece, even a dough piece which does not require to be fermented may be used as a bar-like dough piece to be formed into a bent form.