Abstract:
A closing tool assembly for a clip machine, in particular for a sausage clipping machine, containing: at least one first and at least one second tool holder, which can be moved to positions opposite each other and reversibly towards each other, and each of which supports at least one first and at least one second closing tool, wherein the first and second closing tool are each replaceably held on the first and the second tool holder by means of a fixing device. A linear guide contour is further provided on at least one of the two tool holders, and a linear guide counter-contour complementary thereto is further provided on the associated closing tool.

Description:
[0001]    This patent application claims priority to German patent application DE 10 2007 011 423.2, filed Mar. 8, 2007, which is hereby incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The invention relates to a closing tool assembly for a clip machine, in particular for a sausage clipping machine, according to the preamble of claim  1 . The closing tool assembly has at least one first and at least one second tool holder, which can be moved to positions opposite each other and reversibly towards each other, and each of which supports at least one first and at least one second closing tool, wherein the first and second closing tools are releasably and replaceably held on the first and the second tool holder by means of fixing devices. 
       BACKGROUND OF THE INVENTION 
       [0003]    An example of closing tools for a sausage clipping machine is disclosed in European patent application 1 140 633, (U.S. Pat. No. 6,675,554, which is incorporated herein by reference) for example. A lower die has a trough-like recess embodied such that the base of a clip to be applied and an adjoining portion of the legs of said clip are supported. In addition, an upper die has a concave recess on the side facing the lower die, in which recess the ends of the clip are bent and pressed together when the lower die and the upper die are brought together. 
         [0004]    However, a disadvantage can arise with this very established technique when the closing tools have to be replaced, be it to replace worn parts or to adapt the clip machine to other packaging sizes. This is because, in the known closing tool assembly, the closing tools are fixed to the tool holders by means of screws and the like. When changing the closing tools, it is therefore necessary to loosen these screws, to pull the closing tools out of the retaining elements on the tool holders, then to insert the new tools into the retaining elements on the tool holders and finally to insert the screws into the screw holes on the tool holder and/or the closing tools. In doing so, it is essential to ensure that the closing tools are correctly aligned so that a clip is placed and closed with the desired precision. When performing this work, it is necessary that appropriate working tools are kept ready at the clip machine. Furthermore, when changing the closing tools, work must be carried out with these working tools in a relatively cramped space in the region of the closing tool assembly. The tools required for this work are not usually rustproof. 
       SUMMARY OF THE INVENTION 
       [0005]    In one or more embodiments, a closing tool assembly for clip machines of the kind initially specified is provided, that permits simple and quick replacement of the closing tools. 
         [0006]    By providing a linear guide contour on at least one of the two tool holders and a linear guide counter-contour complementary thereto on the associated closing tool in accordance with the present invention, it is possible to remove the closing tool from the tool holder and to replace it with the desired tool with little effort and without needing additional tools. In order to change one or both closing tools, all that is required is to release the fixing device. The closing tools can then be pulled out of the respective guides formed by the linear guide contour on the tool holder and by the linear guide counter-contour on the closing tool, and new closing tools can be inserted into the guides, an operation which can be carried out quickly and without additional tools. The linear guides also ensure, in a simple manner, that the closing tools are correctly aligned with each other. 
         [0007]    If the linear guide contour of the tool holder and the linear guide counter-contour on the associated closing tool are provided in the planes of the respective contact surfaces, the linear guide contour is not burdened by compressive forces when closing the clips, so the closing tools are not displaced during closing. If, in contrast, the linear guide contour of the tool holder and the linear guide counter-contour on the associated closing tool are arranged at least approximately perpendicular to the plane of their respective contact surfaces, then although these are burdened by the compressive forces when closing the clips, they are not acted upon by any forces in their direction of displacement, as a result of which the closing tools are not displaced relative to the tool holders when closing the clips. The proposed guides are able to absorb forces acting perpendicular to the direction of displacement, which corresponds to the direction of load when closing the clips. 
         [0008]    The linear guide contour and the linear guide counter-contour may be chosen from a wide range of different configurations. It is preferred that the linear guide formed by the linear guide of the tool holder and by the linear guide counter-contour of the closing tool is a flat guide. A prismatic guide, a dovetail guide or a cylindrical guide may also be provided instead of a flat guide. 
         [0009]    It is also advantageous when the linear guide formed by the linear guide contour of the tool holder and by the linear guide counter-contour of the closing tool has at least one positioning stop. By this reliable and simple means, the rear end of the displacement path of the closing tool, viewed in the direction of insertion, is marked, and its position relative to the tool holder defined. 
         [0010]    A wide range of solutions can likewise be provided for the fixing device. It is particularly advantageous when the fixing device has at least one fixing element which can be moved reversibly from a fixing position to a release position. If the fixing device has at least one actuating element for moving the fixing element, preferably manually, from the fixing position to the release position, the fixing element is externally accessible and can thus be operated manually. Tool-less changing of the closing tools is made possible as a result. 
         [0011]    The path of movement of the fixing element may have any orientation relative to the path of movement defined by the linear guide contour of the tool holder and the linear guide counter-contour of the closing tool. If the fixing element can be reversibly moved from the fixing position to the release position in a direction at least approximately perpendicular to the guide direction of the linear guide formed by the linear guide contour of the tool holder and by the linear guide counter-contour of the closing tool, this allows a space-saving arrangement of the fixing device. 
         [0012]    In order to maintain the fixing position of the fixing element in a reliable manner, it is also advantageous when the fixing element is biased into the fixing position by at least one elastic element, preferably by a pressure spring. Instead of elastically biasing the fixing element, the fixing element may also be reversibly movable into two defined positions, i.e. the fixing position and the release position. The two defined positions can be formed by detent elements and the like. 
         [0013]    It is also advantageous when the fixing element has an insertion bevel which simplifies insertion of the closing tools into the linear guide contour. In addition, or alternatively, an insertion bevel which is advantageously embodied to be complementary to the insertion bevel of the fixing element may be provided on the closing tool itself. 
         [0014]    One particularly space-saving configuration of the inventive closing tool assembly can be achieved by mounting the fixing device on the tool holder. 
         [0015]    Other advantageous configurations and an embodiment of the invention shall now be described with reference to the description of an embodiment and to the attached drawings. The terms “top”, “bottom”, “left” and “right” used when describing the embodiment relate to the drawings oriented in such a way that the reference numerals and names of the figures can be read normally. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURE 
         [0016]      FIG. 1  shows a perspective view of an upper die of an embodiment of a closing tool assembly, viewed from the rear side of a clip machine provided with said closing tool assembly; 
           [0017]      FIG. 2  shows a perspective view of a lower die of an embodiment of a closing tool assembly, viewed from the front side of a clip machine provided with said closing tool assembly; 
           [0018]      FIG. 3   a  shows a front view of the upper die of the closing tool assembly; 
           [0019]      FIG. 3   b  shows a sectional view of the upper die along line A-A in  FIG. 3   a;    
           [0020]      FIG. 4   a  shows a front view of the lower die of the inventive closing tool assembly; and 
           [0021]      FIG. 4   b  shows a sectional view of the lower die along line B-B in  FIG. 4   a.    
       
    
    
     DETAILED DESCRIPTION 
       [0022]    As can be seen from  FIGS. 1 and 2 , in particular, an embodiment of a closing tool assembly  10  for a clip machine, in particular for a sausage clipping machine, has as its main components an upper die  20 , and a lower die  40  arranged below upper die  20 . Upper die  20  and lower die  40  can be moved reversibly in the vertical direction (cf.  FIGS. 3   b  and  4   b ) towards and away from each other in order to move from a standby position into a clip closing position and vice versa. In  FIGS. 3   b  and  4   b , upper die  20  and lower die  40  of the closing tool assembly  10  are shown in the standby position, i.e. in their spaced-apart positions. 
         [0023]    During normal operation of a sausage clipping machine, a gathered end or tress of sausage casing material free of filling material, not shown here, is located approximately in the middle between upper die  20  and lower die  40 , in particular in the standby position of the closing tool assembly  10 . A portion of unfilled sausage casing material that is drawn from a supply, and likewise not shown here, adjoins the unfilled tress in the horizontal direction on the one side of closing tool assembly  10 . Adjoining in the opposite horizontal direction, on the other side of closing tool assembly  10 , is a section of sausage casing material which is filled with filling material, in this case sausage meat, and which is in the process of forming a sausage (not shown). At the front free end of the sausage casing section already filled with sausage meat, the sausage casing has been closed by closing tool assembly  10  using a clip C, such that no filling material can escape. 
         [0024]    Clip C may be made of an impressed aluminum wire and combined with a plurality of additional clips C to form a line of clips, not shown here, wherein clips C are pre-bent into a U- or V-shape (see  FIG. 2 ) and joined by means of bent webs at the ends of their side legs. To place a clip C, the frontmost clip C is fed to lower die  40  in the known manner by advancing the line of clips. As long as the frontmost clip C is still attached to the line of clips it is followed by, it is stably held by the latter in lower die  40 . 
         [0025]    In the process of closing clip C, lower die  40  may be moved initially into its closing or end-of-stroke position. In this position, the frontmost clip C is pressed against the unfilled tress of the sausage casing material, which is located approximately in the middle between upper die  20  and lower die  40  when lower die  40  begins to move, and is clamped between said tress and lower die  40 . Upper die  20  then moves towards lower die  40 . Immediately before clip C is closed, the frontmost clip C is separated from the line of clips following it, at first by means of a shearing device which is provided on closing tools  20 ,  40 , but which is not described here in any further detail. At that moment, the frontmost clip C is free and is pressed against lower die  40  by the tension of the tress only. Clip C is then deformed by upper die  20  coming closer to lower die  40  until closing tools  20 ,  40  have come so close to each other that clip C is closed around the tress free of filling material, such that no filling material can escape. 
         [0026]      FIG. 1  shows upper die  20  of the closing tool assembly  10  according to one embodiment of the invention. The main components of upper die  20  are a tool holder  22  and an upper closing die tool  24  forming a first closing tool. Tool holder  22  is fixed by means of a first actuating device of the clip machine, not described here in further detail, which moves tool holder  22  and upper closing die tool  24  in order to move these reversibly from their standby position into the clip closing position. 
         [0027]    The cuboidal tool holder  22  made of steel has a linear guide contour  22   b  of C-shaped cross-section on its upper side  22   a , which in the mounted state points downwards in the direction of bottom die  40 , said linear guide contour  22   b  extending, when likewise in the mounted state, over the entire upper side  22   a  of tool holder  22  in an orientation from the front side V to the rear side R of the clip machine, and which is used to guide the insertion of upper closing die tool  24 . At its rear end, linear guide contour  22   b  is provided with a positioning stop  22   c  which protrudes from the upper side  22   a  of tool holder  22  and which limits the insertion movement of upper die tool  24  and gives the latter a defined position relative to tool holder  22 . 
         [0028]    As  FIG. 3   b  shows, tool holder  22  is releasably mounted on the clip machine, for example by screws which are not defined in any further detail, with such an orientation that positioning stop  22   c  points to, or is located near, the front side V of the clip machine and linear guide contour  22   b  extends from the rear side R of the machine to positioning stop  22   c . In other words, linear guide contour  22   b  is accessible from the rear side R of the machine when tool holder  22  has this orientation. However, tool holder  22  can essentially be mounted on the clip machine with such an orientation that positioning stop  22   c  points to, or is located near, the rear side R of the clip machine and upper closing die tool  24  can be inserted from the front side V of the clip machine into linear guide contour  22   b  of tool holder  22 . 
         [0029]    Upper closing die tool  24 , which is likewise made of steel and which may be approximately anvil-shaped, likewise has on its underside  24   a , which points upwards when tool  24  is in the mounted state, a linear guide contour  24   b , which corresponds as a linear guide counter-contour to linear guide contour  22   b  of tool holder  22  and therefore has a T-shaped cross-section. Between linear guide contour  22   b  of tool holder  22  and linear guide contour  24   b  of upper closing die tool  24 , a light slide fit may be provided so that tool  24  can be inserted easily with its linear guide contour  24   b  into linear guide contour  22   b  of tool holder  22 , from where it can be pulled out again easily. As already mentioned, the insertion movement of upper closing die tool  24  is limited by the positioning stop  22   c  of tool holder  22 , which abuts the rear side  24   c  of tool  24  when the end position is reached. 
         [0030]    Two adjacent but spaced-apart clip shaping portions  24   e  are provided on the upper side  24   d  of upper closing die tool  24 , which points downwards when tool  24  is in the mounted state. As can be seen from  FIGS. 1 and 3   b , the two clip shaping portions  24   e  have the shape of an upside-down letter “V” with a rounded bottom end. By means of the two clip shaping portions  24   e , two clips can be processed simultaneously by upper closing die tool  24 . 
         [0031]    At the end of tool holder  22  opposite positioning stop  22   c , said tool holder is also provided with a fixing or locking device  50  which secures upper closing die tool  24  against sliding out of linear guide contour  22   b  of tool holder  22 . Fixing device  50  may be provided on a cylindrical extension  22   d  of tool holder  22 . For this purpose, extension  22   d  has a blind hole  22   e , in which an actuating hammer  52  of fixing device  50  and forming a fixing element is captively guided in such a manner that actuating hammer  52  may be moved back and forth along the bore axis of blind hole  22   e  between a fixing position and a release position. A helical compression spring or other biasing member  54  which elastically biases actuating hammer  52  in the fixing position bias is also provided between the bottom of blind hole  22   e  and actuating hammer  52 . 
         [0032]    Said actuating hammer  52  may have a hammer head  52   a  which is provided on its side facing tool holder  22  with a stop surface  52   b  abutted by upper closing die tool  24  when the latter is inserted into the linear guide contour  22   b  of tool holder  22 . Hammer head  52   a  is provided on its opposite face with an insertion bevel  52   c , over which upper closing die tool  24  slides with its leading edge when tool  22  is inserted, thus pushing actuating hammer  52  into blind hole  22   e  and its release position against the force of helical compression spring  54 . To facilitate this operation, additional insertion bevels corresponding to insertion bevel  52   c  may be advantageously provided at the end of the closing die tool facing the positioning stop and on the underside thereof. 
         [0033]    Also preferably attached to actuating hammer  52  is an actuating element  52   d , which may be used for manual actuation of actuating hammer  52  in order to remove the upper closing die tool from tool holder  22  in the case of a tool change, for example. By this means, and by means of the linear guide between tool holder  22  and upper closing die tool  24 , it is possible to change the upper closing die tool  24  without requiring any tools. 
         [0034]    After upper closing die tool  24  has been fully installed and engaged with tool holder  22 , actuating hammer  52  is moved back from the release position into the fixing position by helical compression spring  54 , and upper closing die tool  24  is releasably fixed in its position on tool holder  22 . To remove the upper closing die tool  24  from tool holder  22 , all that is required is to press actuating hammer  52  into blind hole  22   e  against the force of helical compression spring  54 , for example manually by means of actuating element  52   d , so that upper closing die tool  24  can be pulled out of linear guide contour  22   b  of tool holder  22 . 
         [0035]      FIG. 2  shows lower die  40  of the closing tool assembly  10  according to the invention. The main components of lower die  40  are a tool holder  42  and a lower closing die tool  44  forming a second closing tool. Tool holder  42  is fixed by means of a first actuating device of the clip machine, not described here in further detail, which moves tool holder  42  and lower closing die tool  44  in order to move these reversibly from their standby position into the clip closing position. 
         [0036]    The likewise cuboidally shaped tool holder  42  made of steel has a linear guide contour  42   b  of C-shaped cross-section on its upper side  42   a , which in the mounted state points upwards in the direction of upper die  20 , said linear guide contour  42   b  extending, when likewise in the mounted state, over the entire upper side  42   a  of tool holder  42  in an orientation from the front side V to the rear side R of the clip machine, and which is used to guide the insertion of lower closing die tool  44 . At its rear end, linear guide contour  42   b  is provided with a positioning stop  42   c  which protrudes from the upper side  42   a  of tool holder  42  and which limits the insertion movement of lower die tool  44  and gives the latter a defined position relative to tool holder  42 . 
         [0037]    As  FIG. 4   b  shows, tool holder  42  is releasably mounted on the clip machine, for example by screws which are not defined in any further detail, with such an orientation that positioning stop  42   c  points to, or is located near, the rear side R of the clip machine and linear guide contour  42   b  extends from the front side V of the machine to positioning stop  42   c . However, tool holder  42  can essentially be mounted on the clip machine with such an orientation that positioning stop  42   c  points to, or is located near, the front side V of the clip machine and lower closing die tool  44  can be inserted from the rear side R of the clip machine into linear guide contour  42   b  of tool holder  42 . 
         [0038]    Lower closing die tool  44 , which is likewise made of steel, likewise has on its underside  44   a  a linear guide contour  44   b , which corresponds as a linear guide counter-contour to linear guide contour  42   b  of tool holder  42  and therefore has a T-shaped cross-section. Between linear guide contour  42   b  of tool holder  42  and linear guide contour  44   b  of lower closing die tool  44 , a light slide fit may likewise provided so that tool  44  can be inserted easily with its linear guide contour  44   b  into linear guide contour  42   b  of tool holder  42 , from where it can be pulled out again easily. Here, too, the insertion movement is limited by the positioning stop  42   c  of tool holder  42 , which abuts the rear side  44   c  of tool  24  when the end position is reached. 
         [0039]    At the end of tool holder  42  opposite positioning stop  42   c , said tool holder  42  is provided with a fixing or locking device  70 , which secures lower closing die tool  44  against sliding out of linear guide contour  42   b  of tool holder  42 , and which has a structure identical to that of the fixing device  50  on upper die  20 . For this reason, no further description is provided (the reference signs are chosen in accordance with fixing device  50  and raised by 20). 
         [0040]    It should be noted, finally, that the invention is not limited to the linear guide contours  22   b ,  24   b  shown in  FIGS. 1-4 . A dovetail guide, a prismatic guide or a cylindrical guide may also be provided as linear guide contours  22   a ,  24   b . It is also possible to configure closing tool assembly  10  in such a way that linear guide contours  22   a ,  24   b  are arranged perpendicular to the contact plane of closing tools  20 ,  30 .