Abstract:
A strapping machine for positioning a strap material around an associated load and tensioning the strap material around the load includes a frame for supporting the load, a chute positioned on the frame for receiving the strap material and orienting the strap material around the load, a strap supply and a strapping head for extracting the strap from the supply, feeding the strap through the chute around the load, passing the strap from the chute around the load, retracting and tensioning the strap. The strapping head includes feed rollers and retraction rollers for feeding and retracting the strap and a winder for tensioning the strap around the load. The winder is positioned between the feed and retraction rollers and the strap supply. The winder includes a rotating head portion having a stationary element and a pivotal element. The stationary and pivotal elements each define an outer surface around which the strap material is wound and a slot therebetween for receiving the strap material. The stationary and pivotal elements each further define a gripping portion at about respective ends opposingly facing one another. The pivotal element is pivotal between an open position in which the gripping portions are spaced from one another and a closed position in which the gripping portions cooperate with one another to engage and secure the strap material therebetween. The winder rotates from a home position in which the winder is in the open position and an other than home position in which the winder is in the closed position to exert a tension in the strap.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention pertains to strapping machines. More particularly, the present invention pertains to an improved drive arrangement for a strapping machine including a rewind member and cutting arrangement.  
         BACKGROUND OF THE INVENTION  
         [0002]    Strapping machines are in widespread use for applying a strap, such as a plastic strap, in a tensioned loop around a load A typical strapping machine includes a strap chute for guiding the strap around the load, a strapping head through which the leading end of the strap is fed, and a strap dispenser to dispense a desired length of strap from a coil of strap material.  
           [0003]    The strapping head carries out a number of functions. It advances the strap along the chute around the load until the leading end returns to the strapping head and retracts or rewinds the strap from the chute to produce tension in the strap around the load. The strapping head typically includes an assembly for securing the strap in the tensioned loop around the load such as by welding the strap to itself at its overlapping portions.  
           [0004]    A typical strapping head includes a pair of advancing rollers for advancing the strap through the strapping head and a pair of retraction rollers for retracting the strap to, for example, take-up the strap. The head also includes a winder or tensioner that rewinds or takes up the strap after it is positioned around the load so as to apply a tension in the strap. In one known configuration, the winder includes a split-type rotating element that has a channel or slot formed therethrough to essentially define split halves of the winder. The split halves are fixed relative to one another and the strap traverses through the slot between the halves. Upon an appropriate signal, the winder is actuated and rotates to tension the strap.  
           [0005]    In a typical winder arrangement, the strap is not in tension until it passes over itself around the winder, thus creating sufficient friction to prevent the strap from slipping through the winder slot. It has been observed that often, the winder must rotate in excess of 360 degrees, and with some types of readily compressible loads, it must rotate more than 720 degrees to provide sufficient friction to begin tensioning and to provide the appropriate tension on the strap.  
           [0006]    In known strapping heads, the winder is positioned intermediate the feed and retraction rollers. An arrangement such as this disclosed in U.S. Pat. No. 4,605,456 which patent is assigned to the assignee of the present application and is hereby incorporated by reference. Although the strapping machine disclosed in this patent functions well, it does have certain drawbacks. For example, it has been found that in known strapping machines, the strap may not automatically refeed after faulted strap is ejected following a jam in the machine or after significant rewinding following load compression. It has also been found that in known strapping head configurations, adjustments may also be necessary in order to accommodate varying gauges of the strap material. It has further been found that the rewinding length may be limited due to structural constraints of the strapping head, winder and drive arrangement.  
           [0007]    Accordingly, there exists a need for a strapping machine having a winder that commences effective tensioning of the strap without the strap having to wind over itself. Desirably, such a winder is effective over a range of strap gauges and can be used with highly compressible loads. More desirably, such a winder permits positioning the winder within the strapping head so as to take advantage of automatically refeeding the strap through the strapping heading following faulted strap ejection.  
         SUMMARY OF THE INVENTION  
         [0008]    A strapping machine for positioning a strap material around an associated load and tensioning the strap material around the load includes a frame for supporting the load, a chute positioned on the frame for receiving the strap material and orienting the strap material around the load, a strap supply and a strapping head for extracting the strap from the supply, feeding the strap through the chute around the load, passing the strap from the chute around the load, retracting and tensioning the strap.  
           [0009]    The strapping head includes feed rollers and retraction rollers for feeding and retracting the strap and a winder for tensioning the strap around the load. Preferably, the winder includes a rotating head portion having a stationary element and a pivotal element, each defining an outer surface around which the strap material is wound. The stationary and pivotal elements define a slot therebetween for receiving the strap material. Each element defines a gripping portion at about a respective end that is opposingly facing the other of the gripping portions.  
           [0010]    The pivotal element is pivotal between an open position in which the gripping portions are spaced from one another and a closed position in which the gripping portions cooperate with one another to engage and secure the strap material therebetween. The winder rotates from a home position in which the winder is in the open position and an other than home position in which the winder is in the closed position to exert a tension in the strap. In a most preferred embodiment, the winder is positioned between the feed and retraction rollers and the strap supply.  
           [0011]    In a preferred winder, the pivotal element is biasedly mounted to the head portion into the closed position and includes a projection extending from the pivotal element for maintaining the pivotal element in the open position when the winder is in the home position.  
           [0012]    The winder includes a drive assembly for rotating the winder head portion. Preferably, the winder includes a winder biasing element, such as a clock-type spring for returning the winder to the home position.  
           [0013]    The strapping machine can include one or more intermediate stop plates positioned between the winder head portion and the frame. The intermediate stop plates permit greater than 360 degree rotation of the winder relative to the strapping machine.  
           [0014]    A preferred embodiment of the strapping machine includes a cam having a feed surface, a retraction surface and an intermediate surface and a linkage assembly for actuating the feed rollers, the retraction rollers and the winder. The preferred linkage includes a single cam-contacting linkage arm configured to bear against the cam.  
           [0015]    The linkage is configured to move the feed rollers into engagement with the strap material and to move the retraction rollers out of engagement with the strap material when the cam-contacting linkage arm bears against the feed surface. The linkage is further configured to move the retraction rollers into engagement with the strap material and to move the feed rollers out of engagement with the strap material when the cam-contacting linkage arm bears against the retraction surface. The linkage further moves the feed rollers and the retraction rollers out of engagement with the strap material when the cam-contacting linkage arm bears against the intermediate surface.  
           [0016]    To this end, the linkage assembly includes a second linkage arm configured to bear against the single, cam-contacting linkage arm. The cam-contacting linkage arm is configured to move the feed rollers into and out of engagement with the strap material and the second linkage arm is configured to move the retraction rollers into and out of engagement with the strap material.  
           [0017]    A most preferred embodiment of the strapping machine includes a cutting assembly positioned between the feed rollers and the retraction rollers. The cutting assembly includes a stationary anvil and a rotating cutting blade defining a pivot. The cutting assembly further includes a drive assembly having a motor-and a camfollower mounted thereto.  
           [0018]    A linkage member is operably mounted to the rotating cutter and has an elongated slot formed therein. The cam-follower is configured for receipt in and movement through the elongated slot. Actuation of the motor moves the cam-follower through the elongated slot to rotate the blade into engagement with the anvil. The blade engages the anvil when the cam-follower is at about a farthest-most position from the pivot.  
           [0019]    In a preferred embodiment, the retraction rollers engage the strap following actuation of the cutting assembly. Most preferably, an ejection chute disposed between the feed rollers and the retraction rollers, and the faulted strap is ejected by the retraction rollers through the chute.  
           [0020]    Other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims. 
       
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0021]    [0021]FIG. 1 is front view of a strapping machine illustrating, generally the components and arrangement thereof, the machine shown with a strapping head embodying the principles of the present invention;  
         [0022]    [0022]FIG. 2 is a front perspective view of the strapping head, the strapping head shown with portions of the frame removed for clarity of illustration, the head further shown without strap material positioned therein;  
         [0023]    [0023]FIG. 3 is a front/side perspective view of the strapping head of FIG. 2 shown with other portions of the frame removed for clarity of illustration, this view shown with strap material traversing through the head in a normal travel path;  
         [0024]    [0024]FIG. 4 is a rear perspective view of the strapping head of FIG. 3, again illustrated with portions of the frame removed for clarity of illustration;  
         [0025]    [0025]FIG. 5 is a front perspective view of the winder and intermediate stop plate, the winder being shown in partial cross-section;  
         [0026]    [0026]FIG. 6 is an exploded view of the winder also shown with an intermediate stop plate; and  
         [0027]    [0027]FIGS. 7 a - d  are schematic views of the relative rotation of the winder and stop plate shown through about 720 degrees of revolution; and  
         [0028]    [0028]FIG. 8 is rear schematic view of the strapping head illustrating the positions of the cutter linkage as it moves through one cutting and eject cycle. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0029]    While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated.  
         [0030]    Referring to the figures and in particular, to FIG. 1, there is shown a strapping machine  10  having a strapping head  12  embodying the principles of the present invention. The strapping machine  10  includes generally a workstation  14  such as the illustrated tabletop on which the load may be rested during the strapping operation. The machine  10  further includes a chute  16  around which the strap S is advanced during the strapping operation and one or more strap dispensers  18  from which the strap S is dispensed to the strapping head  12 . The overall arrangement and operation of such a strapping machine  10  is disclosed in U.S. Pat. Nos. 4,605,456 and 5,299,407.  
         [0031]    The strapping head  12  is that portion of the machine  10  that withdraws or pulls the strap S from the dispenser  18 , feeds the strap S through the chute  16 , grasps the leading edge of the strap so as to bring it into contact with a trailing portion, and tensions the trailing portion so as to compress the load.  
         [0032]    Referring now to FIGS.  2 - 4 , the strapping head  12  includes a frame  20 , a plurality of feed rollers  22   a,b  and a plurality of retraction rollers  24   a,b.  In the illustrated embodiment, two such feed rollers  22   a,b  and two such retraction rollers  24   a,b  are shown. In this embodiment, one of the feed rollers is a driven roller  22   a  while the other is an idler roller  22   b  that rotates only in frictional cooperation with its associated, driven roller  22   a.  Likewise, one of the retraction rollers is a driven roller  24   a  and the other is an idler roller  24   b  that rotates only in frictional cooperation with its associated driven roller  24   a.  The driven rollers  22   a,    24   a  are driven by, for example, the exemplary belts drives  26 . Those skilled in the art will recognize other arrangements by which the rollers  22   a,    24   a  can be driven.  
         [0033]    The strapping head  12  includes a biased, pivotal winder  28  that cooperates with the feed and retraction rollers  22 ,  24 . As shown in FIGS.  2 - 3 , the winder  28  is disposed in close proximity to the feed and retraction rollers  22 ,  24 . Unlike known strapping machines, which position the winder between the feed and retraction rollers, in a preferred embodiment of the present machine  10 , the winder  28  is positioned upstream of the feed and retraction rollers  22 ,  24 . For purposes of the present discussion, upstream shall mean that side of the strapping head  12  from which the strap S material is fed (i.e., between the strapping head  12  and the dispensers  18 ) and downstream shall mean that side of the strapping head  12  to which the strap S is fed, (i.e., toward and around the chute  16 ).  
         [0034]    As provided above, the winder  28  functions to produce tension in the strap S after the strap S is fully distributed around the load, and the “slack” in the strap S has been taken-up (i.e., after the strap S has been retracted). For example, after the strap S has been positioned around the load and in overlapping relation with itself, the retraction rollers  24   a,b  are actuated to retract the strap S to take-up any slack in the strap. The winder  28  is then actuated to further pull the strap S. In this manner, it exerts a tension in the strap S which compresses or bundles the load.  
         [0035]    To this end, in the illustrated embodiment, the winder  28  is shown as having a generally circular profile, that is defined by a pair of generally semicircular elements  30 ,  32  forming a slot or channel, as indicated at  34 , between the elements  30 ,  32 . The slot  34  is sized to accommodate a range of strap gauges (thicknesses) and to permit the strap to move freely through the slot  34  during the feeding and retraction operations of the strapping machine  10 .  
         [0036]    Unlike known rewinding devices, which include stationary halves mounted on a rotating shaft, the present winder  28  includes a stationary element  30  and a pivotal or hinged element  32 . Referring now to FIGS.  5 - 6 , the stationary element  30  is mounted to (or formed as part of) a back plate  36  which in turn is mounted to or formed as part of a shaft  38  about which the winder  28  rotates. The pivotal or hinged element  32  pivots relative to the stationary element  30  about a pivot pin  40  positioned at the upstream side, as indicated at  42 , of the winder  28 . The stationary and pivotal elements  30 ,  32  define a variable gap therebetween. At the upstream-most side  42  of the winder  28 , the stationary and pivotal members  30 ,  32  define gripping portions  44 ,  46  that grip or pinch the strap S therebetween during the winding operation.  
         [0037]    The pivotal element  32  is biased by, for example, a coil spring  48 , into a position so that the stationary and pivotal element gripping portions  44 ,  46  contact one another, i.e., are biased into a closed position. The pivotal element  32  includes an upper stop pin  50  that extends fully through a notched opening  52  in the back plate  36 . The upper stop pin  50  is configured to contact an intermediate stop plate  54 , discussed below, to maintain the pivotal element  32  in the open position during strap S feed and retraction operations. The notched opening  52  in the back plate  36  permits the pivotal element  32  to be maintained in the open position when the winder  28  is at the home position.  
         [0038]    To permit the winder  28  to rotate more than 360 degrees without interference by the upper stop pin  50  preventing such rotation, the intermediate stop plate  54  is mounted between the winder  28  and the frame  20 . The intermediate stop plate  54  rotates about the winder shaft  38  and includes a winder stop  56  and a frame stop  58 . These stops  56 ,  58  extend in opposing directions, longitudinally from about a periphery  60  of the stop plate  54 . An exemplary plate  54  is illustrated in FIG. 6. The winder stop  56  is that stop against which the upper stop pin  50  bears to maintain the winder  28  open in the home position.  
         [0039]    The winder  28  further includes a winder spring  62 , such as the exemplary clock-type spring that is mounted to the shaft  38  to return the winder  28  to the home position after the winding operation.  
         [0040]    Again, also unlike known strapping heads, the present strapping head  12  utilizes a single cam  68  having a plurality of camming surfaces  70 ,  72 ,  74  for actuating a linkage arrangement  76  that engages and disengages the feed and retraction rollers  22 ,  24 . The linkage arrangement  76  is better seen in the rear view of the strapping head  12  in FIG. 4. As will be recognized by those skilled in the art, the feed and retraction rollers  22 ,  24  are driven in opposite directions from one another, and either the feed  22  or retraction  24  rollers are engaged with the strap S at any given time. That is, if the feed rollers  22  are engaged with the strap S to feed the strap S, the retraction rollers  24  are disengaged from the strap S. Conversely, when the retraction rollers  24  are engaged with the strap S to take up slack or retract the strap S, the feed rollers  22  are disengaged from the strap S.  
         [0041]    Additionally, when the winder  28  is used to tension the strap S, both the feed and retraction rollers  22 ,  24  are disengaged from the strap S. As such, any one of the three strap engaging portions of the strapping head  12  (the feed rollers  22 , the retraction rollers  24  and the winder  28 ) operate on the strap S at any one time.  
         [0042]    The present linkage  76  operably connects these operated system portions using a single cam  68  and a single cam-contacting bearing  80  to effectuate proper sequencing and operation of the strapping head  12 . Referring to FIG. 4, the linkage  76  includes a first or feed roller linkage arm  86  that is moved between an engaged position and a disengaged position (as indicated by the arrows at  88  and  90 , respectively), to engage and disengage the feed rollers  22 , respectively. The feed roller linkage arm  86  pivots about a first pivot  92 . A second or retraction roller linkage arm  94  pivots about a second pivot  96  between an engaged position and a disengaged position (as indicated by the arrows at  98  and  100 , respectively) to engage and disengage the retraction rollers  24 . The cam-contacting bearing  80  is positioned on the feed roller linkage arm  86 .  
         [0043]    The cam  68  includes three operating surfaces. A first (highest or feed) surface  70  urges the feed roller linkage  86  into the engaged position  88 . An eccentric secondary linkage  102  (FIG. 2) is mounted on and operably connected to the feed roller linkage  86 . The idler feed roller  22   b  is mounted to the eccentric secondary linkage  102  and is brought into contact with the strap S to suppress the strap S against the driven feed roller  22   a.  The eccentric secondary linkage  102  is biasedly connected to the feed roller linkage  86 , by, for example, a coil spring  104 , to assure that sufficient pressure is maintained on the strap S by the driven feed roller  22   a  so that the strap S is properly fed through the strapping head  12  and chute  16 . When the cam-contacting bearing  80  bears on the second or third operating surfaces (home or intermediate  72 , and retraction or lowest surfaces  74 , respectively), the feed roller linkage  86  moves to the disengaged position  90  to disengage the feed rollers  22   a,b  from one another and from the strap S.  
         [0044]    The retraction roller linkage arm  94  rests on a second portion  82  of the cam-contacting bearing  80  and is biased so that it maintains contact with this portion  82  of the bearing  80 . The retraction roller linkage arm  94  is connected to a carriage  106  that pivots about the frame  20  at the second pivot  96  and biases the linkage  94  against the bearing portion  82  and biases the retraction rollers  24   a,b  into the engaged position. Unlike the feed roller  22  arrangement, the driven retraction roller  24   a  is moved into and out of contact with the idler roller  24   b.    
         [0045]    When the cam-contacting bearing  80  bears on the feed or home surfaces  70 ,  72  (highest and intermediate surfaces, respectively), the retraction roller linkage  94  moves to the disengaged position  100  to disengage the driven retraction roller  24   a  from the idler roller  24   b  and the strap S. As will be understood from a study of the figures, the retraction linkage  94  in these two positions is urged upwardly, as indicated by the arrow at  100 , which pivots the retraction carriage  106  to move the driven retraction roller  24   a  away from the idler roller  24   b.  Conversely, when the cam-contacting bearing  80  bears on the lowest or retraction surface  74 , the retraction linkage  94  moves downwardly, as indicated by the arrow at  98 , which, in turn, moves the driven retraction roller  24   a  into contact with the strap S to suppress the strap S between the retraction rollers  24   a,b  to retract or take-up the strap S.  
         [0046]    During the rewinding or tensioning portion of the strapping cycle, the cam-contacting bearing  80  again bears on the cam retraction surface  74  which moves feed roller  24   b  into the disengaged position  90 . During this portion of the cycle, the retraction rollers  24   a,b  must also be disengaged from one another and from the strap S. To this end, with reference to FIGS. 3 and 5- 6 , a second bearing  110  rides along an outer periphery of the winder  28  and the intermediate stop plate  54 . As the winder  28  begins to rotate, the second bearing  110  is urged out of a small depression  112 ,  114  in each of the winder  28  and intermediate plate  54  peripheries. The depressions  112 ,  114  are aligned with the second bearing  110  when the winder  28  and the intermediate stop plate  54  are in the winder home position. The second bearing  110 , which is mounted to the feed roller linkage  86 , urges the feed roller linkage  86  upward which in turn moves the retraction roller linkage arm  94  upward. The upward movement of the retraction roller linkage arm  94  moves the retraction rollers  24   a,b  into the disengaged position. The winder  28  then continues to rotate clockwise as seen in FIG. 5.  
         [0047]    Referring now to FIGS. 5 and 7 a - d,  as the winder  28  moves off of the home position as seen in FIG. 7 a,  the upper stop pin  50  moves out of contact with the intermediate plate winder stop  56 . This permits the spring  48  to move the winder pivotal element  32  into the closed or gripping position. The friction developed between the gripping portions  44 ,  46  of the winder  28  and the strap S causes the winder  28  to immediately commence tensioning the strap S, without the strap S having to wind onto itself to develop the necessary friction. The pivotal configuration of the winder  28  further enhances the gripping of the strap S. As the winder  28  begins to rotate clockwise as seen in FIG. 5, the strap S exerts a force F on the pivotal element  32  that is tangential to the winder  28  and in a direction opposite to the rotation of the winder  28 . This force F translates to a increased pressure applied to the strap S at the gripping portions  44 ,  46 .  
         [0048]    Referring again to FIGS. 7 a - d,  the winder  28  and intermediate stop plate  54  are configured so that the winder  28  can rotate, in the winding mode, greater than 360 degrees. As seen in FIG. 7 a , as the winder  28  begins to rotate, the upper stop pin  50  moves off of a first side  56   a  of the winder stop  56  on the plate  54 . As the winder  28  continues to rotate, approaching a 360 revolution (FIG. 7 b ), the stop pin  50  contacts a second side  56   b  of the winder stop  56  which permits further rotation of the winder  28  and rotates the plate  54  (FIG. 7 c ). Continuing beyond the first 360 degree revolution, as the winder  28  and stop plate  54  approach 720 degrees of revolution (FIG. 7 d ), the frame stop  58  contacts a stub or like projection  116  extending from the frame  20  which stops the winder  28  and plate  54 . This provides a limit to rotation, which is advantageous from a machine  10  control standpoint.  
         [0049]    As will be recognized by those skilled in the art, additional intermediate stop plates  54  can be positioned between the winder  28  and the frame  20  to permit rotation of the winder  28  beyond about 720 degrees. Each additional intermediate stop plate  54  provides an additional about 360 degrees of rotation. For example, a winder  28  having two intermediate plates  54  can rotate about 1080 degrees (360 degree rotation for the winder  28  plus 360 degree rotation for each of the two intermediate stop plates  54 ). Those skilled in the art will recognize that the degree of rotation is slightly less than 360 degrees because of that portion of the arc that is needed to acconmnodate the winder and frame stops  56 ,  58 , respectively.  
         [0050]    In the next operational step, the strap S is grasped at about the location at which the leading and trailing portions overlap. The leading and trailing portions of the strap are welded or otherwise joined to one another around the load to maintain the load under compression. After the strap is fixed, e.g., welded around the load, the free end of the strap is cut and the load is removed from the strapping machine  10 . This step of the operation is more fully disclosed in the aforementioned U.S. Pat. No. 4,605,546. Subsequently, the winder spring  62  returns the winder  28  to the home position, and the strapping machine  10  is readied for strapping a next load.  
         [0051]    The strapping head  12  is configured so that in the event of a fault, the strapping head  12  will sense the fault, automatically cut the strap S upon receipt of a fault signal and eject the strap from the machine  10 . The head  12  will then automatically refeed the strap S to ready the machine  10  for a next load. Such an arrangement for automatic fault-strap ejection is fully disclosed in Bell, U.S. Pat. No. 5,640,899, which patent is assigned to the assignee of the present application and is incorporated by reference herein.  
         [0052]    A cutter  78  includes a stationary cutting portion or anvil  120  and a rotating cutting portion or blade  122 . During normal strapping operations, the anvil  120  and blade  122  are spaced from one another and the strap S passes between them. Upon receipt of a fault signal, the feed rollers  22   a,b  are disengaged from the strap S, and the cutter  78  is actuated. Referring to FIGS. 2, 4 and  8 , the cutter  78  is mounted to the frame  20  by an eccentric linkage arrangement  124 . A pivot  126  of the linkage  124  rotates a stub shaft  128  to which the cutting blade  122  is attached. The linkage  124  includes an elongated slot  130  at about a distal end  132  of the linkage  124  spaced from the pivot  126 . The cutter drive includes a gear-type motor  134  that rotates a shaft  136  having a cam-follower  138  mounted to an end thereof. The cam-follower  138  is positioned within the linkage slot  130 . When the cutter  78  is in the “rest” state (as indicated at  140 ), the cam-follower  138  is positioned within the slot  130  near to the pivot  126 .  
         [0053]    When the cutter  78  is actuated, the motor  134  drives the cam-follower  138  in an arc. As the cam-follower  138  moves through this arcuate path, it traverses through the slot  130  from the rest position  140 , at which it is near to the pivot  126 , to a position farthest from the pivot  126  (or a “cut” position as indicated at  142 ), while at the same time rotating the linkage  124 . The rotational movement of the linkage  124  brings the cutting blade  122  into contact with the anvil  120 , which in turn severs the strap S positioned between the blade  122  and the anvil  120 . Following the cutting portion of the cycle, the cam-follower  138  continues through its cycle to an eject position (as indicated at  144 ) and the retraction rollers  24   a,b  are actuated and engage the faulted strap to eject the strap through an eject chute provided in the head  12 .  
         [0054]    Following the cutting operation, as will be understood by those skilled in the art, although the faulted strap S has been ejected from the head  12 , it is only that portion of the strap downstream from the cutter  78  that has been ejected. The strap up to the cutter  78 , including the strap that is present in the winder  28  and between the feed rollers  22   a,b  remains in place and intact during the ejection cycle. Thus, after the ejection cycle, the feed rollers  22   a,b  actuate to automatically refeed the strap S through the head  12  to ready the machine  10  for a next load.  
         [0055]    As can be seen in FIGS. 2 and 8, the cutter linkage  124  is configured so that the actual cutting or severing operation (that point at which the blade  122  meets the anvil  120  with the strap S between them) is carried out taking maximum mechanical advantage of the linkage arrangement  124 . At the point at which the blade  122  and anvil  120  meet, the cam-follower  138  is at the farthest-most point of the elongated slot  130 . Thus, because the blade  122  is at about the pivot  126  of the linkage  124 , the cutting force is applied at a maximum or near maximum distance (i.e., with a greatest moment) between the blade  122  and the force.  
         [0056]    From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.