Abstract:
A dough processing device has a support frame, a dough feed device, a dough portioning device, a dough kneading device and a dough transfer device. The latter transfers at least one dough portion from at least one portioning chamber of the dough portioning device to at least one kneading chamber of the dough kneading device during transfer time periods. An adjustment device serves for defining a vertical distance between the transfer device and the kneading chamber. This results in a dough processing machine in which a reliable transfer of dough portions from the at least one portioning chamber to the at least one kneading chamber is ensured even in the case of a high throughput.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a dough processing machine comprising
         a support frame;   a dough feed device;   a dough portioning device;   a dough kneading device; and   a dough transfer device which transfers at least one dough portion from at least one portioning chamber of the dough portioning device to at least one kneading chamber of the dough kneading device during transfer time periods.       

     2. Background Art 
     A dough processing machine of this type is disclosed in DE 102 49 496 A1. This known dough processing machine is still in need of improvement in terms of the transfer reliability from a portioning chamber of the dough portioning device to a kneading chamber of the dough kneading device during operation of the dough processing machine, in particular if a high throughput of the dough processing machine is required. 
     WO 03/022057 A2 discloses a dough processing machine comprising a displaceable cylinder, wherein a vertical displacement thereof permits one to alternate between a larger and a smaller measuring piston of a portioning device of the dough processing machine. 
     It is an object of the present invention to improve a dough processing machine of the type named at the outset in such a way that a reliable transfer of dough portions from the at least one portioning chamber to the at least one kneading chamber is ensured even in the case of a high throughput. 
     SUMMARY OF THE INVENTION 
     This object is achieved according to the invention by a dough processing machine comprising
         a support frame;   a dough feed device;   a dough portioning device;   a dough kneading device; and   a dough transfer device which transfers at least one dough portion from at least one portioning chamber of the dough portioning device to at least one kneading chamber of the dough kneading device during transfer time periods;
 
wherein the dough transfer device is designed such that in a transfer position of the portioning chamber, the dough portion detaches from a discharge piston and falls into the associated kneading chamber, wherein an adjustment device is provided for defining a vertical distance between the transfer device and the kneading chamber.
       

     In accordance with the invention, it has been found that a distance adjustment device enables a transfer path from the at least one portioning chamber to the at least one kneading chamber to be adapted to operating conditions of the dough processing machine, in particular to the type of dough, the amount of dough or the dough density, in such a way that an optimum dough portion transfer is guaranteed in dependence on the prevalent operating conditions. Adapting the vertical distance makes it possible to achieve a targeted fall path of the dough portion from the discharge piston into the associated kneading chamber. This ensures a fast and at the same time reliable transfer, and therefore a high throughput of the dough processing machine. The vertical distance may be set by adjusting the distance between the transfer device and the kneading chamber along a vertical directional component. This adjustment need not be performed in a strictly vertical direction. The adjusting movement of the adjustment device for setting the vertical distance may in particular also be guided in a diagonal direction or along a parabolic curve. This enables the position of the kneading chamber relative to the transfer device to be adjusted along a fall path of the dough portion. 
     An adjustment device that is designed in such a way as to allow a horizontal distance to be additionally defined between the transfer device and the kneading chamber further improves the relative positioning, which is adapted to the respective operating conditions, of the at least one portioning chamber relative to the at least one kneading chamber. Horizontal or lateral momenta acting on the dough portion to be transferred may be taken into account when setting the horizontal or lateral distance by means of the adjustment device. 
     Depending on the design of the dough processing machine, a displacement of the dough kneading device with a vertical directional component by means of a displacement drive of the adjustment device, or a displacement of the dough portioning device with a vertical directional component by means of a displacement drive of the adjustment device may be more advantageous. It is of course conceivable as well to design both the dough kneading device and the dough portioning device in an adjustable manner according to the invention. The displacement drive may be manual or motorized. 
     An adjustment device that is connected to a drive motor which is in a signal connection with a control unit enables the distance between the at least one portioning chamber and the at least one kneading chamber to be defined in an automatically controlled manner, depending on the operating data of the dough processing machine, in particular depending on an amount of dough or a type of dough. 
     A signal connection between the control unit and a drive component of a drive of the dough kneading device permits a controlled transfer of dough portions from the portioning chamber to the kneading chamber by means of a synchronized relative movement of the portioning device and the kneading device receiving the dough portions from the portioning device. This may further improve the transfer reliability. 
     A spindle-type lifting gear of the displacement drive results in an accurate adjustment by means of the adjustment drive. The spindle-type lifting gear may in particular be designed as a self-locking spindle-type lifting gear. Alternatively or in addition thereto, the dough portioning device and/or the dough kneading device may also be locked in the respective adjustment position. This protects respective supports of the adjustment device against harmful effects of vibrations of the dough portioning device and/or the dough kneading device. 
     A guide means of the adjustment drive for guiding a displacement movement of at least one of the group comprising the dough kneading device and the dough portioning device relative to the support frame ensures an accurate adjustment by means of the adjustment device. 
     A dough kneading device in the form of a kneading drum enables a plurality of dough portions to be kneaded in particular simultaneously. The kneading drum may be designed as described in DE 102 49 496 A1 or in DE 103 06 438 A1. 
     A design of the guide means, wherein the guide means is on both sides mounted on stub axles of the kneading drum, and wherein one of the spindly-type lifting gears is assigned to each partial guide means which is in each case assigned to one stub axle, is safe to operate in particular when a heavy kneading drum is used. 
     This applies in particular to a guide means that comprises two linear guides which are in particular designed as recirculating ball bearing guides. 
     A design according of a dough processing machine, wherein the adjustment device is designed such that at least a drive component of the displaced component remains in place when at least one of group comprising the dough kneading device and the dough portioning device is displaced, reduces the weight load, in particular of guide elements of the adjustment device. The potentially heavy drive component remains in place and need not be displaced. 
     A belt-length compensation device of a belt drive, which is a drive component for the dough kneading device, provides for a kneading drum adjustment while simultaneously maintaining a constant tension of the kneading belt. Belt-length compensation may take place by means of a spring bias or alternatively by means of a pneumatic drive. 
     An embodiment of the invention will hereinafter be described in more detail by means of the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  shows a schematic side view of a dough processing machine revealing inner details thereof; 
         FIG. 2  shows a section of components of a lift adjustment device of a kneading device of the dough processing machine according to  FIG. 1 ; 
         FIG. 3  shows a perspective sectional view of the dough processing machine which is shown in more detail than in  FIG. 1  and from a direction similar to that in  FIG. 2 ; 
         FIG. 4  shows an exploded view of details of a linear guide means of the lift adjustment device of the dough processing machine; 
         FIG. 5  shows an exploded view of details of the lift adjustment device in the region of components of the linear guide means which are assigned to an inner kneading device drive; 
         FIG. 6  shows a perspective view of assemblies of the dough kneading device together with the lift adjustment device and the linear guide means; and 
         FIG. 7  shows a schematic and enlarged view of an output end of a discharge piston together with a dough portion while the dough portion is transferred to a kneading cell of the dough kneading device. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A dough processing machine  1  serves for portioning and kneading dough, for instance when making bread rolls. Dough  2  is filled in a feed hopper  3 . The feed hopper  3 , as well as the other components of the dough processing machine  1 , is supported by a support frame  4  which is divided into a drive frame  5  and a frame structure  6 . The drive frame  5  is drivable by way of rollers  7 . 
     A discharge opening at the bottom of the feed hopper  3  is in connection with a delivery chamber in which a delivery piston  8  runs substantially horizontally. The delivery piston  8  and the feed hopper  3  are parts of a dough feed device of the dough processing machine  1 . A delivery movement of the delivery piston  8  is actuated by a crank drive  9  which may for instance be mechanically designed such as described in EP 0 494 367 A1, for example, and is therefore not explained in detail. The crank drive  9  is actuated by a hydraulic cylinder  10 . 
     A bottom  11  near the front of the delivery piston  8  forms a boundary wall of a transfer chamber for a portioned dough piece  12 . A portioning chamber  13 , which is on three sides delimited by two blades of a rotary vane  14  and by a discharge wall  15  (cf.  FIG. 7 ) of a discharge piston  16 , forms a part of the transfer chamber. The rotary vane  14  and the discharge piston  16  together form a part of a dough portioning device of the dough processing machine  1 . Furthermore, the rotary vane  14  and the discharge piston  16  together form a transfer device of the dough processing machine  1 , the transfer device transferring a dough portion, in other words the portioned dough piece  12 , from the portioning chamber  13  to the kneading chamber  21  during transfer time periods. A conventional crank drive, which is not explained in more detail, enables the rotary vane  14  and the discharge piston  16  to be actuated synchronously with the delivery movement of the delivery piston  8 . An outer peripheral wall of the rotary vane  14  slides on a guide wall  17  which is formed in a support body  18  at the bottom of the delivery piston  8 . 
     A discharge roller  19  is arranged below the support body  18  next to the guide wall  17 . 
     The crank drive for the rotary vane  14  is part of a transfer device for transferring the portioned dough pieces  12  from the delivery chamber at the bottom end of the feed hopper  3  to a kneading drum  20  which forms a dough kneading device of the dough processing machine  1 . A transfer takes place from the portioning chamber  13  of the dough portioning device to a kneading chamber or kneading cell  21  of the kneading drum  20 , the kneading cell  21  being in a transfer position. 
     The kneading drum  20  is arranged below the rotary vane  14  and comprises a hollow-cylindrical chamber drum  22 , which is provided with through-holes in the usual manner, and an inner kneading wall  23  arranged coaxially thereto. Parallel to the longitudinal axis of the chamber drum  22 , kneading-cell boundary webs  24  are equally distributed in the peripheral direction of the chamber drum  22 , the kneading-cell boundary webs  24  having a triangular cross-section which widens from the inner kneading wall  23  towards the outer surface of the chamber drum  22 . 
     The kneading cells  21 , which receive in each case one dough piece  12 , are defined by in each case two adjacent kneading-cell boundary webs  24  together with the intermediate sections of the inner kneading wall  23  and a kneading belt  25  which bears against the outside of the chamber drum  22  via a peripheral section. The kneading drum  20  has a total of several tens of such kneading chambers  21 . In the embodiment according to  FIG. 1 , there are eight kneading chambers  21  when seen in the peripheral direction. Perpendicular to the drawing plane of  FIG. 1 , there are approximately eight more of such kneading chambers  21  which are arranged in succession so that the kneading drum  20  may for instance be provided with  64  kneading chambers  21 . 
     A drive of the kneading drum  20  may for instance be designed as described in DE 103 06 438 A1. A drive motor  26  is arranged next to one of the two stub axles of a kneading drum axle which extends along the longitudinal kneading drum axis (cf.  FIGS. 5 and 6 ). 
     The chamber drum  22  is in contact with a kneading-belt conveying part  27  of the kneading belt  25 . The kneading belt  25  is an endless belt which is guided to the kneading belt drive via three deflection rollers  28 , the chamber drum  22  and via a belt drive roller  29 . Seen in the peripheral direction of the kneading belt  25 , the kneading-belt conveying part  27  turns into a discharge conveying part  30  for discharging the kneaded dough pieces  12  from the kneading chambers  21 . Seen in the delivery direction, a dough discharge device  31  is arranged next to an end portion of the discharge conveying part  30 , the dough discharge device  31  having a endless, revolving conveyor belt for discharging the kneaded dough pieces  12 . Actuation of the rotary vane  14 , the discharge roller  19 , the belt drive roller  29  and the dough discharge device  31  may be derived from a main drive  32  of the dough processing machine, the main drive  32  actuating an eccentric wheel  34  via a toothed belt  33 . 
     A vertical distance A between the transfer device  14  and the kneading chamber  21  may be adjusted by means of a lift adjustment device  35  which will hereinafter be described in more detail by means of  FIGS. 2 to 6 . 
     The lift adjustment device  35  has two spindle-type lifting gears  36  which are in a lifting connection with one of the stub axles of the kneading drum  20  by means of in each case one lifting element  37  (also cf.  FIG. 4 ) and in each case one connection plate  38 . The spindle-type lifting gears  36  are in particular self-locking spindle-type lifting gears. The two spindle-type lifting gears  36  are actively connected to one another by way of a connection shaft  39 . A force-transmitting connection coupling is in each case arranged between the two ends of the connection shaft  39  and the two spindle-type lifting gears  36 . The connection shaft  39 , and thus the spindle-type lifting gears  36 , are actuated via a hand wheel  41 . In an alternative embodiment of the dough processing machine  1 , as it is indicated schematically in  FIG. 6 , a drive motor  42  for actuating the connection shaft  39 , and thus the lift adjustment device  35 , may be provided as an alternative or in addition to the actuation via the hand wheel  41 . In this alternative embodiment, the drive motor  42  is in a mechanical operative connection with the connection shaft  39 , as it is indicated by dashed lines in  FIG. 6 . Via a signal line  43 , the drive motor  42  is in a signal connection with a control unit  44  which may be a central control unit of the dough processing device  1 . The control unit  44  may be in a signal connection with at least another drive component, for instance one of the drive motors of the kneading drum  20 , via a signal connection which is not shown in the drawing. 
     A lift-adjusting movement, which may be generated by the lift adjustment device  35 , is provided by two linear guide means  45 ,  46  which are in each case assigned to the two spindle-type lifting gears  36 . The linear guide means  45 ,  46  are in particular designed as recirculating ball bearing guides. One of these two linear guide means, namely the linear guide means  45 , is shown in an exploded view in  FIG. 4 , the other one of the two linear guide means, namely the linear guide means  46  which is adjacent to the drive motor  26 , is shown in an exploded view in  FIG. 5 . 
     The linear guide means  45  has a vertically extending guide rod  47  which is screwed to a support plate  48  of the support frame  4  by means of cylinder head screws. The guide rod  47  is a profiled rod with a dovetail guide profile. An inner cross-section of two guide blocks  49  is formed complementary to this cross-section so that the two guide blocks  49  are able to run on the guide rod  47  with a minimum clearance along the guide rod  47 . The two guide blocks  49  are screwed to a guide plate  50  by in each case four screws, the guide plate  50  in turn being rigidly connected to the connection plate  38 . 
     At the lower end of the guide rod  47 , a stop body  51  is screwed to the support plate  48 , the stop body  51  interacting with a lower front wall  52  of the guide plate  50  acting as a counter body. Components of the second linear guide means  46  which correspond to those of the first linear guide means  45  already described above, are hereinafter denoted by the same reference numerals and are not discussed in detail again. 
     The linear guide means  46  comprises a total of two guide rods  47  which extend vertically as well. The two guide rods  47  are in turn screwed to a support plate  48  of the support frame  4 . Each of these two guide rods  47  has two guide blocks  49  which run along the respective guide rod  47  and of which three guide blocks  49  are visible in  FIG. 5 . Screwed to the total of four guide blocks  49  is a guide plate  50  which is connected to the drive motor  26  in a supporting manner. 
     During a height adjustment of the kneading drum  20  in order to change the distance A, the belt drive roller  29  is not displaced but remains in its relative position relative to the support frame  4 . The dough processing machine  1  therefore comprises a belt-length compensation device which provides the necessary length compensation for the kneading belt  25  when the kneading drum  20  is vertically adjusted. The belt-length compensation device may be a resilient mounting  53  of the deflection roller  28  shown on the right of  FIG. 1 . 
     The dough processing machine  1  works as follows: dough  2 , which is supplied to the dough processing machine  1  via the feed hopper  3 , enters the delivery chamber at the bottom of the feed hopper  3  when the delivery piston  8  is retracted towards the right of the drawing. The delivery piston  8  actuated by the crank drive  9  so as to be guided in the direction of the rotary vane  14  which is oriented as shown in  FIG. 1 . This causes the dough  2  in the delivery chamber to be compressed between the bottom  11  of the delivery piston  8  and the discharge piston  16  of the rotary vane  14 . At the end of the delivery movement of the delivery piston  8  towards the rotary vane  14 , the latter is in a position in which the bottom  11  is relatively close to the peripheral wall of the rotary vane  14 . The compressed dough  2  is then located in the transfer chamber between the delivery piston  8  and the discharge piston  16 . Afterwards, the rotary vane  14  rotates in the clockwise direction, wherein during this rotary movement, the portioning chamber  13  is initially confined between the walls of the two blades of the rotary vane  14 , the discharge wall of the discharge piston  16  and the guide wall  17  of the support body  18 . When the rotary vane  14  continues to rotate, the portioning chamber  13  reaches a position which is approximately opposite to an uppermost of the kneading chambers  21  of the kneading drum  20 . In this transfer position of the portioning chamber  13  relative to the kneading chamber  21 , the discharge roller  19  is activated and causes the dough piece  12  to detach from discharge piston  16  so as to fall into the associated kneading chamber  21 . The precise transfer position of the portioning chamber  13  relative to the associated kneading chamber  21 , which ensures a targeted transfer of the dough piece  12  both in the vertical and in the horizontal direction according to  FIG. 1 , depends on various parameters. These include the type of dough, the amount of dough, the dough density and the relative sizes of the portioning chamber  13  relative to the kneading chamber  20 . If the dough piece  12  consists of a larger amount of dough, a for instance larger distance A between the portioning chamber  13  and the associated kneading chamber  21  may help to achieve a reliable transfer. Furthermore, particular dough consistencies may require the associated kneading chamber  21  to be offset horizontally by a certain amount relative to the portioning chamber  13  so as to ensure a reliable transfer of the dough piece  12 . Depending on the above-mentioned dough parameters, a particular distance A is set via the lift adjustment device  35 . This may be performed manually via the hand wheel  41  or in a controlled manner via the control unit  44  if the drive motor  42  is provided. In addition to that, a desired horizontal or lateral offset of the associated kneading chamber  21  relative to the portioning chamber  13  may be set by actuating the rotary drive of the chamber drum  22 . In contrast to what is shown in  FIG. 1 , the kneading chamber  21  can then not be arranged precisely below the rotary vane  14  but is slightly offset relative to this position when seen in the direction of rotation  54  or opposite to this direction of rotation  54 . The optimum adjustment of the distance A as well as the optimum adjustment of the horizontal distance, which were in each case determined by preliminary tests, may be stored in a table in the control unit  44  so as to be retrieved automatically in dependence on the dough parameters, thus ensuring an automatic setting of an optimum transfer position of the portioning chamber  13  relative to the associated kneading chamber  21  by means of the lift adjustment device  35  and, if necessary, by means of the drive which is assigned to the chamber drum  22 . 
     As soon as the dough piece  12  has been safely transferred to the kneading chamber  21 , the chamber drum  22  rotates in the direction of rotation  54  such that, the kneading chambers  21  are closed towards the outside by the kneading belt  25  during the kneading action of the kneading chamber  20 . Subsequently, the kneading drum  20  performs a relative movement of the rotating chamber drum  22  relative to the inner kneading wall  23  on the one hand and relative to the kneading belt  25  on the other such that the dough pieces  12 , which are located in the kneading chambers  21  between the inner kneading wall  23  and the kneading belt  25 , are effectively kneaded. During the kneading action, the chamber drum  22  is gradually rotated in the direction of rotation  54 . After kneading, the kneaded dough pieces  12  leave the kneading drum  20  via the discharge conveying part  30  of the kneading belt  25  and the dough discharge device  31 . 
     The lift adjustment device  35  is not only applicable for providing an optimum relative position of the portioning chamber  13  relative to the associated kneading chamber  21  but also for actively transferring the dough piece  12 . This will hereinafter be explained in more detail by means of  FIG. 7 . Components which correspond to those discussed above with reference to  FIGS. 1 to 6  have the same reference numerals and are not explained in detail again. 
     In the embodiment according to  FIG. 7 , the lift adjustment device  35  performs a lifting movement along a lifting direction  55  during each transfer of a dough piece  12  from the portioning chamber  13  to the associated kneading chamber  21 . 
       FIG. 7  shows the case in which the discharge piston  16  has discharged the dough piece  12  from the rotary vane  14 . The dough piece  12  still adheres to the discharge wall  15  of the discharge piston  16 . By means of the lift adjustment device  35 , the distance A between the rotary vane  14  and the kneading drum  20  is reduced to such an extent that in this discharge position, the dough piece  12  protrudes into the associated kneading chamber  21 . In order to transfer the dough piece  12  to the kneading chamber  21 , the rotary drive of the chamber drum  22  may now be actuated in the direction of rotation  54  (or in the opposite direction) so that the kneading-cell boundary web  24  comes into contact with the dough piece  12  and detaches the dough piece  12  from the discharge wall  15 , wherein the dough piece  12  safely falls into the associated kneading chamber  21  upon detachment from the discharge piston  16 . 
     In this way, a synchronized relative movement of the kneading drum  20  relative to the movements of the rotary vane  14  and the discharge piston  16  ensures a controlled transfer of the dough piece  12  from the portioning chamber  13  to the kneading chamber  21 . This synchronized relative movement may be achieved by intermittently actuating the lift adjustment device  35  in particular synchronously with the movements of the delivery piston  8  and the rotary vane  14 . 
     In an embodiment of the dough processing machine  1  which is not shown here, the linear guide means  45 ,  46  additionally comprise a locking device for locking the kneading drum  20  in the respective lifting position. The locking device may prevent a negative influence of vibrations of the kneading drum  20  on the linear guide means  45 ,  46 . 
     As an alternative or in addition to a vertical lift adjustment of the kneading drum  20 , a corresponding vertical lift adjustment of the rotary vane  14  is conceivable as well. To this end, the rotary vane  14  may be equipped with a lift adjustment device which may be actuated by a motor, the lift adjustment device corresponding to the lift adjustment device  35  described above in relation to the kneading drum  20 .