Abstract:
In a dough billet kneading machine, in order to be able to remove and clean the partitioning cylinders, which are radially moveable in the partitioning drum, they are grouped in a linear manner into cylinder bars along a generatrix, and these cylinder bars can not be removed in axial direction, but in radial direction, greatly reducing the space required for maintenance operations.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to German Patent Application No. 10 2006 018 626.5-23 filed 21 Apr. 2006. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable 
       THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
       [0003]    Not Applicable 
       INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
       [0004]    Not Applicable 
       BACKGROUND OF THE INVENTION 
       [0005]    (1) Field of the Invention 
         [0006]    This invention relates to portioning units for doughy materials, especially dough in bakeries, as employed in the partitioning of a large charge of dough into defined small portions or dough billets. 
         [0007]    (2) Background Art 
         [0008]    Portioning units are used in industrial baking plants for the partitioning of finished dough according to a preset weight into individual dough pieces (herein referred to as dough billets) and are used to additionally form the dough billets into a flat, round shape, similar to that of a wheel of cheese. However, it is not sufficient to achieve this shape, e.g. after portioning of the dough charge by weight, through forming by means of suitable press plungers. Rather, this shape can be achieved solely through working the dough, i.e. kneading, turning and/or similar impacting of the dough billets. 
         [0009]    For this purpose, automatic dough billet kneading machines are already known which first partition finished dough in a portioning unit into individual dough billets of preset weight, subsequently subjecting the dough billets in a kneading unit to respective kneading operations, wherein the finished dough billets are subsequently proofed for consistency with their target weight and dimensions, and then are distributed by means of so-called spreader conveyor belts in several adjacent tracks, which either convey them to a subsequent kneading unit or to a manual kneading station. 
         [0010]    The core component of the portioning unit is the so-called partitioning drum which has radial indentations disposed on its circumference—typically several of them along individual generatrices of the partitioning drum—the depth of which and, therefore, their displacement being defined by partitioning pistons which form the bottom of the indentations. 
         [0011]    During rotation of the partitioning drum, the dough is being pressed into the indentations, i.e. the partitioning cylinders, in a certain rotational position, by means of a pusher extending along the entire generatrix of the partitioning drum. 
         [0012]    Through a shearing edge securely mounted to the housing and close to the circumferential surface of the partitioning drum, the dough, which has previously been pressed in, is sheared off through further rotation and divided into particular dough volumes, so-called dough billets, which are located within the dough cylinders. Whenever the next generatrix with partitioning cylinders reaches the rotational position of the radially impacting pusher, the radial pusher again pushes dough into the partitioning cylinders. 
         [0013]    The almost continuously rotating partitioning drum, while alternating between fast and slow rotations, moves so that the filled dough cylinders are rotating downward, usually already emptying downward after approximately ¼ of a rotation. Such emptying presently occurs, on the one hand, through gravity affecting the dough and, on the other hand, through the assistance of a compression spring acting upon the rear of the partitioning piston relative to the partitioning drum. 
         [0014]    For this reason, the radial pusher does not only have to overcome the viscosity of the dough, but also the spring force of the partitioning pistons needs to be overcome in order to achieve complete filling of the cylindrical spaces so that relatively high forces have to impact upon the finished dough, thus adversely affecting its structure. 
         [0015]    Allowing for varying dough consistencies with respect to viscosity and pressure resistance is not possible with this setup. 
         [0016]    The dough billets produced by the partitioning drum are subsequently moved into indentations (e.g. hexagonal indentations also disposed on the circumference of the so-called kneading drum) where, despite the continuing rotation of the kneading drum, they are contained and kneaded by means of a kneading belt at least partially covering the kneading drum. 
         [0017]    A drawback to this type of setup is the large time effort for cleaning and repairing the machine, which depending on the amount of dough being processed could be nearly as large as its operating time. 
         [0018]    The dismantling required for cleaning the partitioning drum is very time consuming, and the proper assembly is difficult, resulting in such work being carried out relatively infrequently and in the development of older deposits and contamination in hard-to-access locations which do not conform to modern tenets of hygiene. 
       BRIEF SUMMARY OF THE INVENTION 
       [0019]    Therefore, it is an objective of the present invention to create a portioning unit, and in particular a partitioning drum for same, which facilitates cleaning, maintenance, and repair and which in particular allows for a respective retrofitting of the portioning unit. 
         [0020]    Larger components are created by combining all individual portioning cylinders positioned along a generatrix into one cylinder bar so that only a few cylinder bars need to be removed and reinstalled instead of a multitude of individual portioning cylinders. 
         [0021]    When removing such cylinder bars in axial direction it has proven to be disadvantageous because sufficient space has to be provided next to the partitioning drum and, furthermore, because the frontal head pieces of the partitioning drum must allow such extraction which would require substantial additional work, especially when retrofitting a portioning unit with such a partitioning drum. 
         [0022]    Both of these drawbacks are eliminated by a radial removal of the bars. 
         [0023]    A secure fixing in operating position is achieved through positively locking the cylinder bars into the partitioning drum by radially inserting the cylinder bars, though axially offset by a certain amount relative to the final operating position, and subsequent axial shifting into the operating position. 
         [0024]    Through axial shifting, protrusions located on outer surfaces of the cylinder bar, which are located there in sections, are moved in axial direction below respective opposing protrusions, which are radially located outside of the protrusions of the cylinder bars. The axial motion and the securing in the operating position is effectuated, preferably, by means of a manually operated threaded spindle which is supported at one of the frontal head pieces of the partitioning drum, and relative to which it moves and secures one cylinder bar at a time into its operating position and secures it there or extracts it from the operating position. 
         [0025]    By having not just the portioning pistons but the entire cylinder bar made of plastic material, preferable POM (Polyoxymethylen), and not requiring any embedded metal components, such cylinder bars can be manufactured relatively simply and inexpensively through machining plastic blocks. After removing the cylinder bars from the partitioning drum, cleaning of the bars, especially by mechanical means, is considerably simplified, as when mounted in the partitioning drum. 
         [0026]    The axial shifting for securing the cylinder bars in a form locking manner corresponds maximally to the diameter of a portioning cylinder, and the protrusions along side surfaces of the cylinder bars are each preferably associated with one partitioning cylinder. 
         [0027]    All components of the partitioning drum next to the portioning cylinder which axially extend into its radial area, thus, also the frontal head pieces and e.g. their drive gears for the partitioning drum, are further removed in an axial direction from the cylinder bar in operating position than the axial distance of offset, in order to assure assembly and disassembly without problems. 
         [0028]    In spite of this mounting method of the cylinder bars, stroke of the portioning pistons in the mounting bars is adjustable by having a rear side of the portioning pistons, which is protruding inwards from an interior side of the cylinder bar, rest against a stop curve. 
         [0029]    The stop curve is notably a sheet metal guide plate extending over the entire length of the partitioning drum which allows for all portioning pistons situated on a given generatrix to be synchronously actuated. For this purpose, the guide plate disposes of a constant profile in axial direction. 
         [0030]    The guiding plate can also be divided into individual segments in axial direction which, however, only increases manufacturing costs while keeping the profile constant in axial direction. A sequence of guide curves with different shapes in axial direction for the individual partitioning pistons or the axial sections of the partitioning drum is possible, e.g. in order to produce dough billets of different sizes with one partitioning drum; however, it increases manufacturing costs for the guide curve and for the support cam supporting the guide curve from its radially anterior, radially inner surface. 
         [0031]    The stroke of the partitioning piston and, thereby the size of the dough billets, is adjusted by setting the guiding curve, which can be pivoted between an exterior and an interior pivoting position, constituting the posterior stop of the portioning piston, in a certain pivoting position. 
         [0032]    For this purpose, a shaft is provided on the rotational axis of the partitioning drum and rotatably arranged relative to the partitioning drum, which is equipped with one single continuous or multiple separate inter-aligned eccentric cam lobes, on the exterior contour of which the rear side of the guiding curve is supported. 
         [0033]    By turning the cam shaft, the cam lobe moves the guiding curve outward to a lesser or higher degree from its inner position towards its outer position whereby a spring secures the guiding curve against lifting off from the cam lobe. 
         [0034]    The frame of the partitioning drum, in which on the one hand the guiding plate with its supporting cam lobe and the cylinder bars are mounted, is composed of radial, approximately star-shaped rib segments in welded construction which are axially spaced from each other, placed and welded in place on circle-segment shaped outer surfaces of enveloping plates which close the open spaces between the grooves for the cylinder bars towards the outside. 
         [0035]    In axial direction, the partitioning drum is completed by inserted head pieces serving as end covers, usually provided as turned parts. 
         [0036]    As the extent of contamination, especially with doughs of low viscosity, depends significantly on the amount of dough leaking between filling funnel and the rotating partitioning drum being subjected to pressure, the partitioning drum at its axial ends is fitted with a circumferential circular shoulder which the funnel or dough reservoir envelops from the outside in an interlocking manner. 
         [0037]    This provides an interlocking guide, as well as a mutual seal between partitioning drum and dough reservoir, constituting a form of a labyrinth seal, having a clearance and passage length, among other things, that govern the amount of dough leaking out. 
         [0038]    The radial position in operating mode is selected so that the peripheral surface of the cylinder bars merges into the peripheral surface of the remaining partitioning drum without a rim. 
     
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0039]    Embodiments according to the invention are shown in more detail in the following drawings. 
           [0040]      FIG. 1  shows a dough billet kneading machine in a lateral view. 
           [0041]      FIG. 2  shows the partitioning drum according to the present invention in a longitudinal sectional view. 
           [0042]      FIG. 3  illustrates the partitioning drum according to the invention in a lateral sectional view. 
           [0043]      FIG. 4  is a perspective view the partitioning drum of the present invention. 
           [0044]      FIG. 5  is a perspective view of the cylinder bar of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0045]      FIG. 1  shows a side view of the portioning unit of the present invention wherein the relevant components, such as a radial pusher  4 , a partitioning drum  6 , a kneading drum  120 , and associated conveyor belts, e.g. a kneading belt  140 , and respective guide pulleys of these belts, can be dimensioned perpendicular to the drawing plane of  FIG. 1  in any way depending on the capacity requirements of the unit. 
         [0046]    In the following, an overall description of the kneading sequence is provided with reference to  FIG. 1 . 
         [0047]    Finished dough is filled into a dough container  11  where it passes through an open upper filler port  4 ′ of a radial pusher  4 . 
         [0048]    In a partitioning drum  6 , on its surface, working orifices are disposed, distributed along different generatrices, as can be seen in  FIG. 3 . The volume of these orifices is variable through partitioning pistons  8  moving therein. 
         [0049]    Partitioning drum  6  rotates permanently, being charged through a pushing motion of radial pusher  4  every time a row of portioning cylinders  7  of partitioning drum  6  is located in front of radial pusher  4 , with dough, which radial pusher  4  pushes in front of itself and thereby into the portioning cylinders  7  of partitioning drum  6 . For this purpose radial pusher  4  is being actuated by means of a push rod  5 . 
         [0050]    Since partitioning drum  6  simultaneously continues to rotate, the dough in portioning cylinders  7  is sheared off by a shearing blade  60 , which is located on the circumferential surface of partitioning drum  6  tightly abutting to the housing so that in each portioning cylinder  7  of partitioning drum  6  a discrete volume of dough, the so-called dough billet, is located and has a weight that should match a predetermined target value as closely as possible. 
         [0051]    Such charging of portioning cylinders  7  of partitioning drum  6  is repeated with each row of portioning cylinders  7  passing in front of radial pusher  4 . 
         [0052]    Partitioning drum  6  continues in a clockwise rotation so that the dough volume, filled into partitioning drum  6  just above a centerline, leaves dough drum  6  through pushing portioning pistons  8  out, which are located in partitioning drum  6 , thereby being engaged by an extraction roller, turning counter-clockwise and thereby being extracted from the working spaces. 
         [0053]    Located precisely below this location is a kneading drum  120  which also has indentations in its enveloping surface into which the dough billets drop through appropriately controlling positioning and speed of the kneading drum, which is also rotating continuously. 
         [0054]    Kneading drum  120  also continues to rotate clockwise and, promptly after receiving the dough billets, makes contact with an also rotating kneading belt  140 , which is being held against the kneading drum in a lower right area through guide pulleys  144  to  144 ″. 
         [0055]    One segment of the kneading belt thereby extends horizontally to the right, at the level of kneading drum  120 , through respective transmission by guide pulleys  144 ″ and  144 ′″. In this section, the kneading belt passes beneath a flouring station  142 , which continually disperses flour onto a top surface of the kneading belt. Due to the kneading belt circulating in counter-clockwise direction, this floured side gets in contact with an outer surface of the kneading drum after passing guide pulleys  144 ″ and  144 . 
         [0056]    Guide pulley  144  is located on a lower left side beneath the kneading drum and mounted far enough to the left of kneading drum  120  so that the kneading belt extends to the left roughly horizontally from a lowest point of the kneading drum, forming an approximately horizontal discharge section  141 , where the dough billets rest and are removed after exiting the kneading drum. 
         [0057]    As best illustrated in  FIGS. 3 and 4 , partitioning drum  6  with its round circumferential surface is fabricated as a welded structure in which panel-shaped, partially perforated rib components  34  are successively arranged in several radial planes through which a centrally aligned opening is disposed. Rib components are connected via the segment-shaped sheets, which are arranged to form shell components  35  over an exterior periphery of all rib segments  34 , and welded together thus forming a contiguous peripheral surface over most of the circumference of partitioning drum  6 . 
         [0058]    As can be seen in  FIGS. 3 and 4 , gaps open to the outside are disposed in all rib sections  34  in three locations equally distanced along the circumference, over which the exterior shell elements  35  do not extend. Inserted then into these longitudinally extending grooves or channels  40  are cylinder bars  29 , an individual bar shown in  FIG. 5  as well as in a longitudinal sectional view in the upper half of  FIG. 2 . After being locked into a working position, outer circumferential surface  29   a  of cylinder bars  29  is flush with the outer circumference of shell elements  35 , resulting in a closed cylindrical shell surface of partitioning drum  6 —except for portioning cylinders  7  disposed in cylinder bars  29 . 
         [0059]    Portioning cylinders  7  are disposed as radial pass-through openings, radially extending from an exterior surface  29   a  to an opposing inner surface through cylinder bars  29 , and are preferably arranged at regular intervals in axial direction, each having a cylindrical cross section. 
         [0060]    As best represented in  FIG. 2 , portioning pistons  8  are fitted into each portioning cylinder  7  so each can move in a radial manner, each front face being flush with the enveloping surface of partitioning drum  6  in its most forward position, and in each of its most retracted positions defining a portioning volume  8   a  between each outer front face and the outer circumference of the partitioning drum, which determines the volume of the dough billets produced by the machine. 
         [0061]    As best represented by  FIG. 5 , cylinder bars  29  dispose on their longitudinal outer surfaces at lower levels in longitudinal direction a number of protrusions  30  which are similarly arranged at regular intervals on both longitudinal outer surfaces of cylinder bars  29 . 
         [0062]    In side flanks of channels  40  of partitioning drum  6  are counter protrusions  31 , the axial extension of which is marginally inferior to the length of the distances  30 ′ between protrusions  30 , which in turn have distances  31 ′ which are marginally larger than axial extension of protrusions  30  on cylinder bars  29 . 
         [0063]    Furthermore, the length of channels  40  relative to the length of cylinder bars  29  and to the radial position of the counter protrusions  31  in partitioning drum  6  are dimensioned so that it is possible to push cylinder bars  29  from the outside inwards in a radial direction, with their protrusions  30  passing through the counter protrusions  31 ′ of the partitioning drum towards the inside to the point where protrusions  30  are resting entirely within counter protrusions  31 ′. Cylinder bar  29  can then be axially displaced by a distance approximately equal to the width of a protrusion  30  which results in its front face striking a stop, mounted preferably in an end cover  36  of partitioning drum  6 , where it is held radially in a form locking manner through protrusions  30  and counter protrusions  31 , which are in line with each other by now. The longitudinal displacement is being effectuated through a threaded spindle  32  which is supported in one of the end covers  36   a  in a corresponding inside thread in an axially rotatable manner although coupled to cylinder bar  29  in a longitudinally fixated manner. 
         [0064]    The thread is self-locking so that cylinder bar  29  can not shift from this position by itself once it has assumed its working position. 
         [0065]    As shown in  FIG. 2 , the same end cover  36   a  also supports a drive gear  33  which has a smaller diameter than the exterior diameter of drum  6 , so that spindles  32  located with each cylinder bar  29  can be axially threaded out and can thereby be threaded over drive gear  33 . 
         [0066]    In side flanks of cylinder bars  29 , in longitudinal direction and above protrusions  30 , extends a continuous groove with its width matching that of the radial extension of counter protrusions  31  for guiding these counter protrusions  31 . Above a groove  41  a protrusion  42  extends further outward and sideways than protrusions  30 , which serves as a radial stop limiting the insertion of the cylinder bars towards the inside. 
         [0067]    In the lower left position of  FIG. 2 , a portioning piston is shown in a portioning cylinder. 
         [0068]    This shows that its radial extension corresponds to that of the portioning pistons, i.e. that of the cylinder bar  29 . When portioning piston  8 , relative to its extended position as shown in  FIG. 2 , transitions into its reversed position for receiving dough it then radially protrudes on the inside from cylinder bar  7  and is supported on an outer circumference of guide plate  21 , which does not co-rotate with partitioning drum  6  and serves as a control curve. 
         [0069]    As best seen in  FIG. 3 , the guide plate is made from two parts, thus a first fixed guide plate component  21   a  which extends over approximately two-thirds of the circumference in the interior of the partitioning drum, and a second movable guide plate component  21   b  which is connected with the first guide plate component  21   a  at one end through a swivel joint  28 . 
         [0070]    As shown in  FIG. 1 , during the partitioning drum&#39;s travel between the dough receiving position and the dough expelling position only about 100 to 120 degrees of angle is covered, and exactly this sector is controlled by the movable part of the guide plate, which is pivotable, because the radial pivotal position of this guide plate  21   b  constitutes the innermost, retracted position of portioning piston  8 , thereby controlling the volume of dough billets being produced, which is to be variable and adjustable. 
         [0071]    The radial motion curve of portioning piston  8  between a charging position  38  and a discharging position  39 , where portioning piston  8  needs to still be or again be in the outermost extended position, is controlled by the curvature of the guide plate  21   b , which is per se not modifiable. 
         [0072]    Modifiable, however, is the pivotal position of this movable guide plate component  21   b , which is supported on its rear surface by one or several longitudinally spaced eccentric cam lobes  12  against which movable guide plate  21   b  is held by a tension spring not seen. 
         [0073]    Eccentric cam lobe or lobes  12 , respectively, are rotationally fixed to a camshaft  17  which extends through a central longitudinal passageway through all rib components and, therefore, through the entire partitioning drum  6 , as well as through both end covers  36  closing the front faces of partitioning drum  6 , protruding outward at least on one side, thereby being accessible and adjustable by rotating it relative to the partitioning drum  6  in order to adjust the portioning volume  8   a.