Abstract:
The invention relates to a device for driving a splitting tool holder intended for an animal carcass splitting machine including a main carriage having sliding guide means for a splitting tool holder; a splitting tool holder supporting a splitting tool; means for driving the splitting tool in order to make it operational; operation programming means; means for slidingly driving the tool holder carried by the main carriage and connected to the tool holder and means for controlling said driving means, characterised on the one hand, by electric driving means which can be stopped in one or several adjustable precise known positions considered as reference positions for the splitting tool; on the other hand, in that the control means are able to control not only the operation and stoppage of the electric driving means but also the adjustment in position thereof, in order to adjust the reference position of the splitting tool according to the needs; the reference positions for the splitting tool being selected among the following: initial retracted position, initial splitting position, final splitting position, final retracted position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to French Application No. 0706805, filed Sep. 28, 2007, which is incorporated by reference herein. 
       BACKGROUND AND SUMMARY 
       [0002]    The invention relates to the driving of a splitting tool holder of an animal carcass splitting machine. It more particularly concerns on the one hand a device for driving a splitting tool holder, more particularly intended for an animal carcass splitting machine, on the other hand, an animal carcass splitting machine including such driving device. The invention more particularly relates to pig carcasses and to carcasses of other animals of the same type. 
         [0003]    Machines for splitting animal carcasses, i.e. pigs, are already known, which include:
   a main carriage, forming a movable frame, having sliding guide means for a splitting tool holder,   a splitting tool holder supporting a movable splitting tool, said splitting tool holder being slidingly movable on the main carriage between a retracted position and an initial splitting position where the distal end of the splitting tool is able to interfere with a carcass positioned to be processed by the machine,   a device for driving the splitting tool holder and thus the splitting tool itself,   means for driving the splitting tool in order to make it operational,   and means for programming the operation of the machine.
 
Conventionally, the device for driving the splitting tool holder includes a pneumatic jack providing the motion between two fixed end positions i.e. a totally folded position and a totally unfolded position. The sliding stroke between such two end positions is determined by mechanical stops (or protrusions) arranged on the main carriage and the splitting tool holder.
   
 
         [0009]    In another known way, such a machine further includes a front supporting device and/or a back supporting device, which is movable and/or deformable, able to rest on the carcass processed by the machine on the front side and/or the back side, respectively. The front supporting device is positioned on the same side as the splitting tool holder and the splitting tool. The back supporting device is positioned on the side opposite the splitting tool holder and the splitting tool. More precisely, the front supporting device and/or the back supporting device is carried by the main carriage, i.e. the splitting tool holder. 
         [0010]    Besides, in another way, the splitting tool holder includes sliding means and motion driving and/or dumping means for the front supporting device (possibly the back supporting device), which is carried by the splitting tool holder in a sliding way along a to and fro direction. Means supporting the animal carcasses to be processed are associated with such a machine and arranged to provide the running of carcasses to be processed in the machine. 
         [0011]    According to the embodiments, the splitting tool is either one or an assembly of knives (FR-A-2535944) or a circular saw blade driven in rotation (U.S. Pat. No. 5,655,960, EP-A-1125502) by suitable driving means. According to the embodiments, the machine includes either one assembly positioned on one side of the means supporting the animal carcasses to be processed (U.S. Pat. No. 5,655,960), or two assemblies positioned on either side of such supporting means (FR-A-2535944, EP-A-1125502). In this later case, a first assembly includes the main carriage, the splitting tool holder, the splitting tool and the front supporting device, whereas a second assembly includes the back supporting device. 
         [0012]    According to one embodiment (EP-A-112550219), the first assembly includes a first column supporting the main carriage, the splitting tool holder, the splitting tool and the front supporting device, whereas the second assembly includes a second column supporting the back supporting device, the first column and the second column forming a single package assembly. With such a machine, in the various configurations it may have, the operation programming means are programmed so that during the operation and whereas a carcass is in a position to be processed by the machine:
   the splitting tool holder is brought to the splitting initial position desired,   and the carcass is positioned through the implementation of the front supporting device and the back supporting device.
 
Then, of course, the splitting tool is operated. According to the embodiments, the machine is programmed to provide either a complete splitting of the carcass into carcass halves or a partial splitting while leaving an unsplit strip of skin at the back and towards the head (this cut is known as the “American cut”).
   
 
         [0015]    In the case where the splitting tool is a circular saw blade, the latter wears when and as it is operated and must be sharpened from time to time. The result is that the diameter of the saw blade diminishes over time, which is a problem. As a matter of fact, whereas with a new saw blade, a distal end of the saw blade may be placed in a position determined for an optimum splitting, when and as the saw blade gets worn, the distal end thereof gets further and further—backwards—from such optimum position. This is the reason why the machine may be used under conditions which are not really optimum—which involves the inherent consequences on the quality of the splitting carried out—or if the same splitting quality is aimed at, the machine must be adjusted while acting on the mechanical limit stops for the sliding of the splitting tool holder, as suggested in the document U.S. Pat. No. 4,653,150. Such an adjusting operation which aims at slidingly moving the splitting tool holder, is difficult to carry out and takes time, which reduces the machine output. 
         [0016]    The same problem occurs when the characteristics of the carcasses processed vary over time. So far, carcass splitting machine is operated at least in a series of operation cycles with identical carcasses as regards the type of animal, for example pigs, and analog carcasses as regards their characteristics more particularly the shape and the size thereof. In spite of this, the relative position between the distal end of the saw blade and the carcass is not perfectly constant because of the—even slight—variations in the shape and the size of the successive carcasses processed by the machine. 
         [0017]    The invention aims at solving these various problems with a solution of a simple and robust construction and easily operated. For this purpose and according to a first aspect, the invention relates to a device for driving a splitting tool holder, more particularly intended for a machine splitting animal carcasses, and more particularly pigs, said machine including:
   a main carriage forming a frame having sliding guide means for a splitting tool holder,   a splitting tool holder supporting a movable splitting tool, said splitting tool holder being slidingly movable on the main carriage along a to and fro direction; when the splitting tool holder is in the initial position, said splitting tool holder being slidingly movable on the main carriage between a retracted position and an initial splitting position where the distal end of the splitting tool is able to interfere with the carcass C processed by the machine; when the splitting tool holder is in the final position, the splitting tool holder being slidingly movable on the main carriage between a final splitting position and a retracted position where the splitting tool is able not to interfere with the carcass C,   means for driving the splitting tool in order to make it operational,   and means for programming the operation,
 
said device including slidingly driving means for the splitting tool holder, carried by the main carriage and connected to the splitting tool holder, and means for controlling said driving means,
 
characterised:
   on the one hand, by electric driving means which can be stopped in one or several adjustable accurate and known position or positions considered as reference positions for the splitting tool,   on the other hand, in that the control means are able to control not only the operation and the stoppage of the electric driving means, but also their adjustment in the correct position, in order to adjust the reference position of the splitting tool as requested.   
 
         [0024]    The reference positions for the splitting tool are selected among the following positions: initial retracted position, initial splitting position, final splitting position, final retracted position. More particularly, the initial splitting position is related with the wear intensity of the splitting tool, in this case a circular saw blade. 
         [0025]    According to one embodiment which the driving device is particularly well adapted to, the splitting tool is a circular saw blade rotatingly mounted in operation. According to another embodiment, the splitting tool is a knife or a set of knives. According to one embodiment, the electric driving means include a motor or a gear motor carried by the main carriage driving a movable member which the splitting tool holder is kinetically connected to. According to a particularly advantageous embodiment, the motor or the gear motor is of the brushless type. According to various possible embodiments, the movable member kinetically connected to the splitting tool holder is an endless belt, a link or a cable, a rack or a screw. 
         [0026]    According to one embodiment, the control means are responsive to a manual control or to a signal from a programmable automatic machine or presence or distance estimation means. More particularly and as regards the wear intensity of the circular saw blade mentioned above, the control means are more particularly responsive to the wear intensity of the saw blade and thus to the diameter thereof, so that the initial sawing position of the saw blade remains constant whatever the wear intensity of the blade. In this case, the wear intensity is visually determined—either by a human being or by a suitable equipment—or according to the machine programming means, for example depending on the number of cycles accomplished. 
         [0027]    According to another embodiment, in relation with the problem of varying animal types processed by the machine (pigs, piglets or a calf for example), the control means are responsive to the type and/or the characteristics of the carcass. Eventually, the control means may be responsive to the type of splitting to be carried out (complete cut or American cut), and/or at least a pre-programmed control of the means for programming the machine operation, depending on the production requests. 
         [0028]    According to a second aspect, the invention consists of a machine for splitting animal carcasses, more particularly pigs, including:
   a main carriage forming a movable frame, having sliding guide means for a splitting tool holder,   a splitting tool holder supporting a movable splitting tool, said splitting tool holder being slidingly movable on the main carriage between the retracted position and an initial splitting position where the distal end of the splitting tool is able to interfere with the carcass positioned to be processed by the machine,   means for driving the splitting tool in order to make it operational,   and means for programming the operation,
 
such machine being characterised in that it includes means for driving the splitting tool holder as described above.
 
According to one embodiment, the machine also includes a front supporting device and/or a back supporting device, which may be movable and/or deformable, able to rest on the carcass processed by the machine on the front side and/or the back side respectively, the front supporting device being positioned on the same side as the splitting tool holder and the splitting tool, the back supporting device being positioned on the side opposite the splitting tool holder and the splitting tool.
   
 
         [0033]    In this case and according to one embodiment, the front supporting device and/or the back supporting device is carried by the main carriage, and more particularly by the splitting tool holder. For this purpose, the splitting tool holder includes sliding means and driving means and/or means for dumping the motion of the front supporting device and/or the back supporting device, carried by the splitting tool holder in a sliding way and along a to and fro direction. According to the embodiments, the means for programming the machine operation are programmed either for a complete splitting of the carcass into two carcass halves or for a partial splitting of the American cut type. 
         [0034]    According to one embodiment, means for supporting the animal carcasses to be processed are associated with the machine and arranged to provide the running of the carcasses to be processed in the machine. According to the embodiments, the machine is made with either only one assembly positioned on one side of the means supporting the animal carcasses to be processed or in two assemblies positioned on either side of such supporting means. In the latter case, a first assembly includes the main carriage, the splitting tool holder, the splitting tool and the front supporting device, whereas a second assembly includes the back supporting device. According to one embodiment, the first assembly includes a first column supporting the main carriage, the splitting tool holder, the splitting tool and the front supporting device and the second assembly includes a second column supporting the back supporting device. In this case and according to one embodiment, the first column and the second column form a single package assembly. 
         [0035]    With an animal carcass splitting machine as has just been described, the machine operation programming means are programmed so that in operation and when a carcass is in a position to be processed by the machine:
   the splitting tool holder is brought to the initial splitting position desired,   and the carcass to be processed is brought in position through a combined implementation on either side of the carcass of the back supporting device and the front supporting device, said combined implementation being based on an action/reaction effect between the air pressures of the chambers of the jacks of the back supporting device and the front supporting device. Then, the splitting tool is operated. In the case where the operation programming means are programmed for a partial splitting of the American cut type, the front supporting device slides to the side where the back supporting device is positioned, while maintaining said combined implementation of the back supporting device.   
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0038]    Several embodiments of the invention will now be described, while referring to appended drawings, wherein: 
           [0039]      FIGS. 1A and 1B  particularly illustrate on one side a machine for splitting pig carcasses, in one embodiment where the machine is composed of two assemblies on either side of the means supporting the carcasses to be processed, one where the splitting tool—here a saw blade—is found, and the front supporting device, the other in a position where the back supporting device is positioned. The saw blade, which is new or not worn in the case of  FIG. 1A , has an original nominal diameter D. It has a certain wear intensity with a reduced diameter d with respect to the value in the case of  FIG. 1B . 
           [0040]      FIG. 2  illustrates on one side a possible embodiment of the driving system according to the invention, in one embodiment where the machine is made of two assemblies, with the splitting tool holder supporting the front supporting device, whereas the back supporting device is carried by an opposite distinct carriage. In this figure, the carriage carrying the saw blade is in a frontward position. 
           [0041]      FIG. 3  is a perspective view, from the top, of the driving device of  FIG. 2 . 
           [0042]      FIG. 4  is a partial and exploded perspective view, from the bottom, of the driving device of  FIGS. 2 and 3 . 
       
    
    
     DETAILED DESCRIPTION  
       [0043]    Now reference is made to  FIGS. 1A and 1B  which schematically illustrate a machine  1  for splitting carcasses C of animals, in this case pigs, having a head  t , back legs  p , a front side  v  and a back side  d . The invention can be applied to the case of carcasses of animals similar to pigs—as regards the splitting to be carried out—for example calves. 
         [0044]    Means supporting  2  carcasses C i.e. by the rear legs  p , with the head t being oriented downwards, are associated with the machine  1 . Such supporting means  2  include, for example, an endless conveying device extending horizontally and supporting, at more or less regular intervals, gambrels or hooks which the rear legs  p  are hanging from. Such supporting means  2  provide the running of carcasses C to be processed, horizontally and in a vertical plane Pc shown in the figures by a drawing thereof. 
         [0045]    In the embodiment shown in  FIGS. 1A and 1B , the machine  1  is made of two assemblies  3 ,  4  positioned on either side of the plane Pc, and thus of the supporting means  2 . The first assembly  3  (positioned in  FIGS. 1A and 1B  on the right side of the supporting means  2 ) includes a first frame  3   a  and a first column  5  carried by the first frame  3   a . The first column  5  supports a main carriage  6 , a splitting tool holder  7 , the splitting tool  8 —in this case a saw blade—and a front supporting device  9 . The splitting tool  8  may be a knife or a set of knives. The second assembly  4  (positioned on the figures on the left side of the support means  2 ) includes a second frame  4   a  and a second column  10  carried by the second frame  4 a. The second column  10  supports a back supporting device  11 . 
         [0046]    In one embodiment, the first column  5  and the second column  10  form a generally U-shaped single package assembly, slidingly carried by a superstructure of the machine, on a horizontal stroke, parallel to the carcass running plane, along the means  2  supporting the carcasses C. Driving means are provided for this purpose. The general structure of such a machine is described in document EP-A-1 125 502 which reference can be made to. In another embodiment, the machine is made of only one assembly, positioned on one side of the plane Pc and thus of the supporting means  2 . The general structure of such a machine is described for example in document U.S. Pat. No. 5,655,960 which reference can be made to. 
         [0047]    The main carriage  6  forms some kind of intermediate movable frame for the saw blade holder  7 , the saw blade  8  and the front supporting device  9 . The main carriage  6  is slidingly mounted on the first column  5 , on a certain vertical stroke, through the sliding means—refer to the rollers  20  guiding the carriage  6  in FIG.  3 —and suitable driving means. The main carriage  6  includes means  18   a  for slidingly guiding the saw blade holder  7  and provided with additional means  18   b . Such guiding means  18   a ,  18   b  are arranged so that the saw blade holder  7  can slide horizontally, perpendicularly to the carcass running plane Pc. Such sliding motion extends either towards this plane (or in front or frontward) or in the direction opposite such plane (or backwards). 
         [0048]    In one embodiment, the means  18   a  are of the guide rail type and means  18   b  are of the slider type. As can be seen in  FIGS. 2 and 4 , the means  18   b  of the slider type are positioned upwards and towards the back the blade holder  7 , with the blade holder  7  being positioned frontward in a cantilevered position. 
         [0049]    Therefor, the saw blade holder  7  is movable between a retracted position and an initial splitting position which corresponds to  FIGS. 1A and 1B , wherein the distal end  12  of the saw blade  8  (the furthest from the first frame  3   a ) is able to interfere with a carcass C positioned to be processed by the machine. As shown in  FIGS. 1A and 1B , such initial splitting position is defined by a reference vertical plane Pr. The plane Pr is parallel to the carcass running plane Pc. The plane Pr is shown in  FIGS. 1A and 1B . The reference plane Pr is here positioned in  FIGS. 1A and 1B  on the left of the carcass running plane Pc i.e. it is positioned beyond the carcass running plane Pc with respect to the first assembly  3 . 
         [0050]    The main carriage  6  also supports means  19  for driving the splitting tool  8  in order to make it operational, in this case, a motor able to pivot the saw blade  8 . Such means  19  are visible in  FIG. 3  but they are not shown for reasons of clarity in the drawing of  FIGS. 2 and 4 . In this case, the motor  19  is positioned towards the back of the blade holder  7 , underneath the slider type means  18   b.    
         [0051]    The front supporting device  9  and the back supporting device  11  are so arranged as to be movable and deformable. They are able to rest on the carcass C processed by the machine on the front side v and the back side d through rollers  9   a ,  11   a . These devices  9 ,  11  are aimed at defining the precise positioning of the carcass C to be processed with respect to the position of the saw blade  8  so that the splitting or the sawing is carried out precisely at the desired location. 
         [0052]    The front supporting device  4  is positioned on the same side as the saw blade holder  7  and the saw blade  8  whereas the back supporting device  11  is positioned on the side opposite the saw blade holder  7  and the saw blade  8 . In fact, the front supporting device  9  is indirectly carried by the main carriage  6  and more precisely by the saw blade holder  7  which includes sliding means and means for driving and/or damping the motion of the front supporting device  9  along a to and fro direction. As for the back supporting device  11 , it is carried by a carriage  11   b  slidingly mounted on the second column  10 , on a vertical stroke through the sliding means and the driving means. 
         [0053]    The machine  1  also includes a device  13  for driving the cutting blade holder  7  on the main carriage  6  along a to and fro direction, perpendicularly to planes Pc and Pr. The driving device  13  firstly includes sliding means  14  for driving the cutting blade holder  7 , carried by the main carriage  6  and connected to the cutting blade holder  7 . The driving device  13  includes secondly means for controlling the driving means  14 . The machine  1  also includes means for programming its operation. The programming means are programmed either for a complete splitting of the carcass C in two carcass halves or for partial splitting of the American cut type. 
         [0054]    The device  13  for driving the cutting blade holder  7  is such that, in the first place, the driving means  14  are electric driving means which can be stopped in a position corresponding to an adjustable precise and known initial splitting position, corresponding to the reference plane Pr. In the embodiment considered, the electric driving means  14  include a motor or a gear motor  14   a  carried by the main carriage  6  driving a shaft  14   b  where a toothed wheel  16   a  driving a movable member  15  is placed, wherein the saw blade holder  7  is kinetically connected. Typically, such motor or gear motor  14   a  is of the brushless type. The device  13  driving the cutting blade holder  7  is such that secondly the control means are able to control not only the operation and the stoppage of the electric driving means  14 , but also the adjustment thereof in position, so as to adjust the initial splitting position of the saw blade according to the needs, i.e. whatever the wear intensity of the saw blade  8  which means that even though the diameter thereof is the initial nominal maximal diameter D ( FIG. 1A ) or a reduced diameter ( FIG. 1B ), its distal end  12  is in the reference plane Pr. 
         [0055]    The movable member  15  kinetically connected to the saw blade holder  7  is, in the embodiment shown in  FIGS. 2 ,  3  and  4 , a belt positioned between the toothed wheel  16   a  and a tooth wheel  16   b , the tooth wheel  16   a  being positioned towards the back of the main carriage  6  whereas the toothed wheel  16   b  is positioned towards the front of the carriage while being sufficiently distant from the toothed wheel  16   a  to allow the required sliding stroke, whereas the axles of the toothed wheels  16   a ,  16   b  are positioned horizontally and parallel to planes Pr and Pc. In other embodiments, the movable member  15  is an endless link or cable, a rack or an endless screw. The synchronous belt  15  is fixed to the saw blade holder  7  at an attachment point—or area— 17 . 
         [0056]    Generally, the means controlling the driving device  13  are responsive to a manual control or to a signal from a programmable automatic machine or presence or distance estimation means integrated or functionally associated in/with the machine. As a matter of fact, the control means are responsive to the wear intensity of the saw blade  8  and thus to the diameter thereof so that the initial sawing position remains constant whatever the wear intensity of the blade. The wear intensity of the saw blade  8  is determined visually either—by a human being or by a suitable equipment such as a visual recognition, presence detection or distance measurement—or according to the machine programming means. For example, a certain theoretical diameter of the saw blade  8  is defined after a certain number of operation cycles of the machine  1 . Thus, the operation may be more or less automatic. 
         [0057]    In another embodiment, alone or combined with the previous one, the driving device  13  is such that the control means are responsive to the type and/or to the characteristics of the carcass and/or to the splitting type to be carried out (for example a complete splitting or an American cut), and/or to at least one previously programmed controlled of the means for programming the machine operation. For example, depending on the characterisation of the carcasses to be processed as “small carcass” or on the contrary, “big carcass”, the driving device  13  will act on the saw blade holder  7  in a more or less forward or backward position. With such a driving device  13 , the members constituting the machine  1  have to fulfil new functions. 
         [0058]    As a matter of fact, the means for programming the machine  1  operation are programmed so that in operation and while a carcass C is in the situation of being processed by the machine  1 :
   the saw blade holder  7  is brought to the sawing initial position desired,   then the carcass C to be processed through the combined implementation, on either side of the carcass C, of the back supporting device  11  and the front supporting device  9  is positioned.
 
Then, the carcass C is sawn. The combined implementation of the devices  9 ,  11  is based on an action/reaction effect between the air pressures in the chambers of the jacks of the back supporting device  11  and the front supporting device  9 .
   
 
         [0061]    If so required, the means for programming the machine  1  operation are programmed for a partial splitting of the American cut type. In this case and in order to leave an unsplit strip of skin in the back and at the bottom of the carcass C, the front supporting device  9  slides to the side where the back supporting device  11  is positioned, while maintaining the combined implementation of the back supporting device  11  and the front supporting device  9 . The result is that the carcass C is pushed frontward which makes it escape from the saw blade.