Abstract:
A device for parting a strip ( 6 ) of binding material that has been fitted around an article ( 5 ), such as a roll of sheet material or bundle of sections and the like, comprising a housing ( 1 ) provided with a support ( 12 ) for supporting the device with respect to the article ( 5 ), two blades ( 7, 8 ) connected to the housing ( 1 ), at least one blade ( 8 ) of which can be moved with respect to the housing ( 1 ), drive means ( 37 ) for moving the blades with respect to one another between an open position and a closed position for cutting through and/or snipping through the strip ( 6 ) when the housing ( 1 ) is bearing on the article, and a clamp ( 16 ) for holding the parted strip. The clamp ( 16 ) and one of the blades can be brought into interaction with one another to clamp the strip ( 6 ) between them.

Description:
REFERENCE TO RELATED APPLICATIONS 
     The present application is a Continuation in Part of application Ser. No. 10/886,092 filed Jul. 6, 2004 now abandoned, entitled “Device for Cutting Through a Binding Strip”, which claims priority of Application No. 1023884 filed in The Netherlands on Jul. 10, 2003, the entire contents of which are herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to a device for parting a strip of binding material that has been fitted around an article, such as a roll of sheet material or bundle of sections and the like, comprising a housing provided with a support for supporting the device with respect to the article, two blades connected to the housing, at least one blade of which can be moved with respect to the housing, drive means for moving the blades with respect to one another between an open position and a closed position for cutting through and/or snipping through the strip when the housing is bearing on the article, and a clamp for holding the parted strip. 
     A device of this type is disclosed in EP-A 945 351. In this known device a clamping plate is arranged alongside a movable blade, which clamping plate must ensure, together with an opposing plate rigidly mounted on the housing, that the strip does not fly off under the influence of the pretension therein once it has been cut through. If the pretension in the strip is on the high side, the strip can, however, suddenly rupture completely right at the start of the snipping or cutting operation. The consequence of this can be that the strip ruptured in this way nevertheless flies off because the clamp has not yet been able to grip the strip properly. 
     SUMMARY OF THE INVENTION 
     The aim of the present invention is to provide a device of the abovementioned type with which flying off of the strip can be better prevented. Said aim is achieved in that the clamp and one of the blades can be brought into interaction with one another to clamp the strip between them. 
     With the device according to the present invention it can be guaranteed that the strip is reliably clamped between the clamp and the movable blade. Only then is the definitive cutting or snipping operation carried out. 
     It is known to make one blade movable with respect to the housing and the other fixed. According to the invention with this arrangement the clamp is accommodated in the housing such that the movable blade comes into interaction therewith during its movement, but before the actual cutting or snipping operation between said movable blade and the fixed blade takes place. 
     It is furthermore known to provide restraining means on the housing to restrain the strip while the movable blade moves against it. The function of said restraining means is to prevent the strip being pushed along by the movable blade without a cutting or snipping action being obtained. This is important if the fixed blade has a cutting edge that runs in the direction of movement of the movable blade and thus is not able to provide any resting effect itself. According to the present invention the restraining means comprise two restrainers that, transversely to the direction of movement of the blade, are some distance apart such that the movable blade can be moved between them. One of the restrainers can move with respect to the housing, transversely to the support, such that it is possible to take into account a more or less severely curved shape of the strip around the article. 
     The clamp can be held pressed into the housing under spring pretension, such that when the strip is clamped the clamp can be moved against the spring pretension. Preferably, the clamp and the blade have correspondingly oriented and/or shaped surfaces for clamping the strip between them. The cutting edge of the movable blade is defined by a cutting face that can be slid along a corresponding cutting face of the other blade, as well as a stop face that runs transversely thereto and can be slid along and in contact with a corresponding stop face of the clamp. The strip can be reliably clamped between these stop faces, in particular if the movable blade has a bearing face on the side facing the support and the stop face runs at an acute angle with respect to the bearing face. 
     To further enhance a reliable retaining action on the strip that has been cut through or snipped through, a pressure foot which is located alongside the clamp can additionally be provided, which pressure foot is designed to provide the effect of pressing the strip against the article. In addition, it is possible that the pressure foot can be pressed against the strip under spring pretension. The pressure foot is preferably on the same side of the blades as the clamp. This ensures that in any event one end of the strip can be reliably held even if the clamp should fail for whatever reason. 
     The housing can be joined by means of a spring suspension to a cap that has means for fixing the latter to a robot arm and the like. In that case even if the robot arm were unable to follow an imprecise surface of the article satisfactorily, the housing can nevertheless make contact with the article and the strip in the correct manner. In this context it is also advantageous if the housing has resilient supporting means on the support side for engaging on the article. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features of the present invention can be more readily understood from the detailed description below with reference to the accompanying drawings wherein: 
         FIG. 1  is a front view of a device for cutting through a binding strip according to an embodiment of the present invention; 
         FIG. 2  is a top view of a device for cutting through a binding strip according to an embodiment of the present invention; 
         FIG. 3  is a side view of a device for cutting through a binding strip according to an embodiment of the present invention; and 
         FIG. 4  is a side view of a restrainer, which is part of a device for cutting through a binding strip according to an embodiment of the present invention. 
         FIG. 5  is a three dimensional view taken from the back of a device for cutting through a binding strip according to an embodiment of the present invention. 
         FIG. 6  is a three dimensional view taken from the front of a device for cutting through a binding strip according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The device shown in  FIGS. 1-6  comprises a housing  1  that is suspended by means of springs  2  from a cap  3 . This cap  3  is attached to the end of a robot arm  4  that is known per se, is not shown in more detail and by means of which the device can be manipulated in the desired manner relative to the article  5 . The springs  2 , cap  3  and robot arm  4  collectively form a support that supports the housing  1  with respect to the article  5 . This article  5  is a roll of sheet material that is kept in the rolled-up state by means of a strip of binding material  6 . 
     The housing  1  has a fixed blade  7  as well as a movable blade  8  that is mounted on the guide  9 . The movable blade  8  can be moved back and forth by means of the drive  37  between the retracted position to the right, shown by continuous lines in  FIG. 3 , and the position in which it has been moved forward to the left, shown by broken lines. In the position in which it has been moved forward, the cutting edge  10  of the fixed blade  7  and the cutting edge  11  located on face  13  of the movable blade  8  have moved along one another, through which movement the strip  6  is cut through. As can be seen in  FIG. 3 , the cutting edge  10  of the fixed blade  7  is essentially horizontal, that is to say parallel to the bearing face  12 , whilst the cutting edge  11  on face  13  of the movable blade  8  runs obliquely and is at an acute angle to the bearing face  12 . In this arrangement, as the wedge-shaped blade  8  moves left, it slides underneath strip  6 , lifting it towards blade  7  until strip  6  is cut by the cutting edges  10  and  11  of blades  7  and  8 . 
     In the plan view in  FIG. 2 , in which the movable blade is shown in the retracted position by broken lines, it can be seen that the blade  8  has a top surface  13 . This top surface  13  likewise runs obliquely, analogously to the cutting edge  11 . The cutting edge  11  is thus defined by the intersection of face  13  running obliquely upwards and the cutting side  14  of blade  8 . Cutting side  14  is perpendicular to the plane of view. Likewise, as shown in  FIG. 3 , fixed blade  7  has a side  15  that runs in the same direction as the cutting edge  10 . Because cutting side  14  of the movable blade  8  is parallel to side  15  of the fixed blade  7 , sides  14  and  15  can be moved alongside each other such that a strip  6  can be snipped between cutting edges  10  and  11 . Specifically, as shown in  FIGS. 1-3 , as front edge  99 , which is formed by the intersection of bearing surface  12  and top surface  13 , of movable blade  8  moves left towards strip  6 , front edge  99  is located below strip  6 , i.e. between strip  6  and article  5 . As front edge  99  passes beneath strip  6 , face  13  of moveable blade  8  pushes strip  6  upwards against cutting surface  10  of fixed blade  7 . As moveable blade  8  continues to move to the left in  FIG. 3 , strip  6 , which is caught between cutting edge  10  of fixed blade  7  and cutting edge  11  of movable blade  8 , is snipped by cutting edges  10  and  11  in a scissor-like action. 
     Corner  90  is formed by bearing surface  12  and cutting side  14  of movable blade  8 . Similarly, corner  95  is formed by bearing surface  12  and opposing side  85  (also of movable blade  8 ), which is located opposite and approximately parallel to cutting side  14 . Because bearing surface  12  is not exactly perpendicular to cutting side  14 , corner  90  is slightly lower than corner  95 , as can be clearly seen in  FIG. 1 . Likewise, in  FIG. 3 , corner  90  is clearly lower than corner  95 . Additionally, bearing face  12  can actually be seen in  FIG. 3  as the white surface between corners  90  and  95 . 
     Front edge  99  of movable blade  8  is formed by the intersection of bearing surface  12  and top surface  13 . Because corner  95  is higher than corner  90 , front edge  99  runs obliquely in the view of  FIG. 2 . This becomes more obvious in  FIG. 3  wherein front edge  99 , which forms an angle that is less than 90 degrees with respect to cutting side  14 , appears to form an even more acute angle with cutting side  14  because corner  95  is higher than corner  90  in this figure. As can be seen more clearly in  FIGS. 2 and 6 , bearing surface  12  rises upwards as it extends away from cutting side  14 , thereby causing the angle of front edge  99  to appear to form a more acute angle with cutting side  14  than it actually does. Front edge  99  is not a cutting surface. 
     When snipping through or cutting through the strip  6  by means of the blades  7 ,  8 , it is best to hold the ends of the strip  6  firmly to prevent flying off. To this end the clamp  16  is provided in the housing which clamp  16  is held resiliently pressed towards the strip  6  under pretension of the spring  17 . The clamp  16  has a lower surface  18  that is shaped correspondingly and runs parallel to the top surface  13  of the movable blade  8 . As soon as this blade  8  is moved forwards, towards the strip  6 , the latter is clamped between the correspondingly shaped faces  13 ,  18  of the blade  8  and the clamp  16 , such that the strip is secured against flying off. The strip is then cut through as the movement of the blade  8  progresses further. 
     The pressure foot  19  is provided as a further security measure to prevent the cut through strip  6  from flying off. This pressure foot is located transversely alongside the clamp  16 , above the strip  6 , as can also clearly be seen in  FIGS. 1 and 2 . The pressure foot is pressed towards the strip  6  under pretension of the spring  20 . This means that when the housing  1  is brought into contact with the article  5  the pressure foot  19  is already pressed, under resilient pretension, against the strip  6  that has not yet been cut through. If, for whatever reason, for example as a consequence of a very high pretension in the strip  6 , the latter is not reliably gripped by the faces  13 ,  18  of the blade  8  and the clamp  16 , it is nevertheless ensured that the strip  6  is held clamped between the pressure foot  19  and the article  5 . 
     The housing  1  furthermore has resilient supports  21 , with a pin  22  that is in contact with the article  5  under resilient pretension. By this means it is always ensured that the housing  1  is positioned correctly with respect to the article  5  and the strip  6 , even if the position by the robot arm  4  is less precise. 
     Finally, the housing has two restrainers  23 ,  24 . The purpose of these is to restrain the strip  6  should this be displaced when the movable blade  8  moves. As can be seen in  FIGS. 2 and 3 , when moveable blade  8  contacts strip  6 , strip  6  is normally displaced vertically against clamp  16 , after which the strip is snipped between cutting surfaces  10  and  11 . However, it is possible that the moveable blade  8  will also displace strip  6  horizontally to the left as moveable blade  8  pushes against strip  6 . In the event that strip  6  is displaced to the left as moveable blade  8  pushes against strip  6 , strip  6  will come into contact with the faces of the restrainers  23 ,  24 , thereby preventing any further horizontal displacement of strip  6 . 
     The restrainers  23 ,  24  are fixed with respect to the housing  1 , and can be held pressed against the article  5 . To that end, both restrainers  23 ,  24  comprise an upper restrainer part  25  and a lower restrainer part  26  which is movable in vertical direction with respect to the upper restrainer part  25 . 
     In the case of  FIG. 3 , the lower restrainer part  26  has been pushed upwardly against the upper restrainer part  25 . In the case of  FIG. 4 , the lower restrainer part  26  has been moved downwardly somewhat with respect to the upper restrainer part  25 . In this connection, the lower restrainer part  26  comprises two pins  27 , which are slidably accommodated in the bores  28  in the upper restrainer part  25 . 
     Furthermore, a bolt  29  is screwed in the screw-threaded hole  30  of the upper restrainer part  25 . Said bolt  29  has a head  31 , accommodated in a widened hole  32  in the lower restrainer part  26 . A compression spring  33  is accommodated in the relatively wide holes, parts  34 ,  35 , of the upper restrainer part  25  and the lower restrainer part  26  respectively. By means of the compression spring  33 , the lower restrainer part  26  is constantly urged towards the extended position as shown in  FIG. 4 . The head  31  prevents the lower restrainer part from being pushed further away. By pressing the lower restrainer part  26  onto a roll to be treated, the lower restrainer part  26  is pushed up to and against the upper restrainer part  25 , as shown if  FIG. 3 . 
     Thus, the compression spring  33  ensures that the restrainers  23 ,  24  are held under pretension against the roll, thus providing a correct abutment for the strip  6  to be cut.