Abstract:
A strapping machine configured to position a strap material around an associated load when in a feed mode and to tension the strap material and seal the strap material to itself around the load when in a tensioning mode includes an improved winder assembly. The machine includes a flame, a strap material supply and a strapping head. A strap path is defined from the strap material supply to the strapping head. The strapping head includes a feed element for conveying the strap material during the feed mode in a first direction around the load and for conveying the strap material in a second, opposite direction to tension the strap material around the load. The strapping head includes a rotating winder for tensioning the material around the load. The winder has a peripheral strap path and a central strap path. The strap material moves through the central strap path when the strap material is conveyed in the first and second directions and wraps around the peripheral strap path after the strap material has moved in the second direction and when in the tensioning mode. The strapping head further includes a winder arm configured to cooperate with the winder. The winder arm is biased to rest against the winder to direct strap material to a predetermined region of the strapping machine when the strapping machine transitions from the rewind mode to the feed mode.

Description:
CROSS-REFERENCE TO RELATED APPLICATION DATA  
       [0001]    This application claims the benefit of priority of U.S. Provisional Patent Application Serial No. 60/429,640, filed Nov. 27, 2002. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention pertains to a strapping machine. More particularly, the present invention pertains to a strapping machine having an improved winder assembly including a winder arm.  
           [0003]    Strapping machines are well known in the art. These machines, also referred to as strappers, are used for positioning, tensioning and sealing a strap around a load. The strapping machines are used for a wide variety of objects from piles of lumber to newspapers and magazines to bales of hay and cotton.  
           [0004]    Strapping machines are of two types, namely hand-held models and table top models. These machines can be made for use with metal or plastic straps.  
           [0005]    In a typical, tabletop plastic strapping machine, the overall machine is mounted to a stationary or moveable worktable. The machine includes, generally, a strap supply, a strapping head, a strap chute and a tabletop or bench to which the components are mounted.  
           [0006]    One drawback to known plastic strap tabletop strappers is that the strap path from the supply to and around the chute can be difficult to access. That is, in the even that maintenance is required or that it is necessary to clear a misfed strap along any part of the strap path (from the strap supply to the chute), it is often necessary to disassemble a large portion of the machine, accessing the strap path thought a variety of doors and hatches, in order to clear the machine for proper operation.  
           [0007]    Another drawback is that physically, many of these machines are quite large. That is, a relatively large amount of floor space (due to a large foot print) is needed in order for proper operation of the machine and in order to provide sufficient space around the machine to conduct maintenance, repair and the like.  
           [0008]    Accordingly, there exists a need for an improved strapping machine having a readily accessible strap path. Desirably, such a strapping machine includes easily cleared, biased slack box guides. More desirably, such a strapping machine includes quick release door latches to provide ready, full access to the strap path. A desirable machine includes double-hinged doors to provide access to the strap path. Such a machine includes a torsion bar/contact tab system to facilitate releasing the strap from the strap chute. More desirably, such a machine includes chute brushes for sequential stripping of the strap from the chute, a limited access head door and drop down roller sets to provide quick and ready access to the strap path and more particularly the strap chute.  
         BRIEF SUMMARY OF THE INVENTION  
         [0009]    A strapping machine configured to position a strap material around an associated load when in a feed mode and to tension the strap material and seal the strap material to itself around the load when in a tensioning mode includes an improved winder assembly. The machine includes a frame, a strap material supply and a strapping head. A strap path is defined from the strap material supply to the strapping head.  
           [0010]    The strapping head includes a feed element for conveying the strap material during the feed mode in a first direction around the load and for conveying the strap material in a second, opposite direction to tension the strap material around the load.  
           [0011]    The strapping head includes a rotating winder for tensioning the material around the load. The winder has a peripheral strap path and a central strap path. The strap material moves through the central strap path when the strap material is conveyed in the first and second directions and wraps around the peripheral strap path after the strap material has moved in the second direction and when in the tensioning mode.  
           [0012]    A winder arm is configured to cooperate with the winder. The winder arm is biased to rest against the winder to direct strap material to a predetermined region of the strapping machine when the strapping machine transitions from the rewind mode to the feed mode.  
           [0013]    Preferably, the winder arm is mounted to the strapping machine frame about a pivot and the winder is biased by a spring, such as a coil spring, operably connected to the winder arm intermediate the pivot and a free end of the winder arm. Most preferably, the winder arm includes a roller mounted to an end of the arm. The roller is configured to rest against the winder.  
           [0014]    These and 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 SEVERAL VIEWS OF THE DRAWINGS  
       [0015]    The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying figures, wherein:  
         [0016]    [0016]FIG. 1 is a front perspective view of the strapping machine in accordance with the principles of the present invention;  
         [0017]    [0017]FIG. 2 is a rear perspective view of the strapping machine showing a strap dispenser mounted to the machine;  
         [0018]    [0018]FIG. 3 is front view of the machine showing the bottom portion of the strap path paddles, the turning element and the winder and biased winder arm at the inlet to the strapping head;  
         [0019]    [0019]FIG. 4 is a perspective view of the strap path, showing the strap path forming paddles in the closed path position;  
         [0020]    [0020]FIG. 5 is a perspective view of the strap path paddles in the open path position;  
         [0021]    [0021]FIG. 6 is an exploded view of the control system enclosure;  
         [0022]    [0022]FIG. 7 is a view of the control system enclosure of FIG. 6 assembled;  
         [0023]    [0023]FIG. 8 is a top perspective view of the upper corner of one of the enclosure panels (doors) and the frame, showing the upper hinge pintle and the quick-release latch;  
         [0024]    [0024]FIG. 9 is a top view of the quick-release latch of FIG. 8;  
         [0025]    [0025]FIG. 10 is a perspective view of the enclosure panel shown with the latch (shown in phantom) in the open position;  
         [0026]    [0026]FIG. 11 is a perspective view of the enclosure panel shown with the latch (shown in partial phantom) in the closed position for insertion onto the hinge pintle;  
         [0027]    [0027]FIG. 12 is a perspective view of a portion of the front of the machine showing the double-hinged slack box and head cover doors, with the slack box door closed and the head cover door closed;  
         [0028]    [0028]FIG. 13 is a partial view of the bottom of the double-hinged doors;  
         [0029]    [0029]FIG. 14 is a partial view of the top of the double-hinged doors;  
         [0030]    [0030]FIG. 15 is a rear view of the head cover door showing the floating strap guide and interlock;  
         [0031]    [0031]FIG. 16 is a partial perspective view of the strap chute and the first vertical and second horizontal chute release torsion elements, the chute being shown in the closed or track forming position;  
         [0032]    [0032]FIG. 17 is a view of the strap chute similar to FIG. 16 showing an article or load to be strapped and showing the chute in the open position and release of the strap material from the chute and travel toward the article;  
         [0033]    [0033]FIG. 18 is a perspective view of an opposite upper corner of the chute;  
         [0034]    [0034]FIG. 19 is a view of the strap chute of FIG. 18 in which the chute is shown open and strap is released from the chute;  
         [0035]    [0035]FIG. 20 shows two partial cross-sectional views of the strap chute as it is moved to release the strap from the chute, and showing, schematically, the stripper element for stripping the strap from the chute;  
         [0036]    [0036]FIG. 21 is a perspective view of a bottom corner of the chute in the closed position;  
         [0037]    [0037]FIG. 22 is a view of the strap chute of FIG. 21 in which the chute is shown open and strap is released from the chute;  
         [0038]    [0038]FIG. 23 is a perspective view of the opposite bottom corner of the chute shown in the closed position;  
         [0039]    [0039]FIG. 24 is a view of the strap chute of FIG. 23 in which the chute is shown open and strap is released from the chute;  
         [0040]    [0040]FIGS. 25 a  and  25   b  are a schematic representations of chute brush configurations for sequentially stripping strap from the strap chute, FIG. 25 a  showing a varying gap width configuration and FIG. 25 b  showing a varying exposed bristle length configuration;  
         [0041]    [0041]FIG. 26 is an exploded view of the infeed and outfeed roller sets positioned on either side of the strap chute (the strap chute being removed for easy of viewing);  
         [0042]    [0042]FIG. 27 is a view of the roller set of FIG. 26 showing the infeed roller set, in phantom lines, pivoted downwardly from the operating position; and  
         [0043]    [0043]FIG. 28 is a view of the roller set of FIG. 26 showing the outfeed roller set, in phantom lines, pivoted downwardly from the operating position. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0044]    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.  
         [0045]    It should be further understood that the title of this section of this specification, namely, “Detailed Description Of The Invention”, relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.  
         [0046]    Referring now to the figures and in particular to FIGS. 1-2, there is shown an improved strapping machine  10  embodying the principles of the present invention. The machine  10  includes, generally, a frame  12 , a strap supply such as the illustrated dispenser  14 , a slack box  16 , a strapping head  18  and a strap chute  20 . The machine  10  includes an in-feed roller set  22  and an out-feed roller set  24  for in-feeding and out-feeding the articles or load to be strapped.  
         [0047]    The frame  12  supports the strapping machine components. The dispenser  14  can be mounted to the frame  12  as illustrated, or alternately, it can be a separate, stand-alone strap S storage and dispensing unit.  
         [0048]    The slack box  16  is also mounted to the frame  12 . A feed arrangement  26  pulls strap from the dispenser  14  to feed into the machine  10 . The slack box  16  is configured to temporarily store a quantity of strap material S to provide a more consistent flow of strap material from the dispenser  14 . The strap S may be stored as a result of take-up from the strapping cycle.  
         [0049]    In the present arrangement, the feed arrangement  26  at the slack box  16  includes a driven wheel  30  and an idler wheel  28 . A contact switch, indicated generally at  32 , located in the slack box  16  actuates a motor  34  to drive the driven wheel  30  to pull strap from the dispenser  14 . The contact switch  32  is located along an end of the slack box  16 . In this manner, when there is strap S present in the slack box  16  contacting the switch  32 , the motor  34  for the driven wheel  30  is stopped. Conversely, when strap S is pulled from the slack box  16  away from the switch  32 , the motor  34  is actuated to drive the driven wheel  30  to pull strap material S from the dispenser  14  so that a quantity of strap is present in the slack box  16 .  
         [0050]    Referring to FIGS. 1 and 3- 5 , strap traverses from the slack box  16  to the strapping head  18  through a first portion of the strap path indicated generally at  36 . The strap path first portion  36  is defined by a pair of opposing, path forming elements or paddles  38 ,  40  that form the path through which the strap travels from the slack box  16  to the strapping head  18 . The paddles, which are inner  38  and outer  40  paddles, move toward and away from each other. Movement of each paddle  38 ,  40  is independent of the other paddle. The paddles  38 ,  40  define a strap path entrance  42 , near the slack box  16 , and a strap path exit  44 .  
         [0051]    Unlike known strap paths, this paddle  38 ,  40  arrangement provides ready access to the strap path  36  for clearing strap or debris therefrom. The paddles  38 ,  40  are mounted to the machine  10  by biased locking pin assemblies  46 . Referring to the inner paddle  38 , this paddle  38  is pivotally mounted to the frame  12  at a pivot pin  48 . The biased locking pin assembly  46  is mounted to the frame  12  through an elongated notched opening  50  in the paddle  38 . As illustrated, a locking pin assembly  46  is shown mounting the inner paddle  38  to the frame  12 . The notched opening  50  permits pivoting the inner paddle  38  (about the pivot pin  48 ) between a closed chute position (FIG. 4) and an open chute position (FIG. 5). The pivot  48  is spaced from the locking pin  46 .  
         [0052]    A collar  52  is fitted around a pin  54 , which collar  52  locks into the paddle opening  50 . By pulling the collar  52  outwardly against the biasing element, e.g., spring  56 , the paddle  38  is unlocked and can be pivoted with the pin portion  54  of the locking pin assembly  46  traversing through the notched opening  50 . In the closed path position, the paddle  38  is locked in place by the collar  52  fitting into an enlarged portion  58  of the elongated opening  50 . By pulling the collar  52  outwardly, away from the paddle  38 , the collar  52  is released from the paddle  38  and the paddle  38  can be pivoted such that the pin portion  54  traverses through the elongated opening  50 . The inner paddle  38  is thus moved to the open chute position.  
         [0053]    The outer paddle  40  is likewise pivotally mounted to the frame  12  (by a pivot pin  58 ) and includes the locking pin  46  arrangement. The outer paddle pivot pin  58  is positioned at about the strap path exit  44 . In this manner, when both the inner  38  and outer  40  paddles are moved to the open path position, sufficient space, indicated generally at  60 , is provided between the paddles  38 ,  40  (in the otherwise constricted strap path  36 ) to permit clearing any misfed strap or debris from the strap path.  
         [0054]    The locking pin on the outer paddle  40  is mounted to the paddle  40  over a slide flange  62 . The flange  62  includes a gripping region  64  to facilitate readily pulling the collar with one hand while urging the outer paddle  40  open using the slide flange  62  with the other hand. In that the outer paddle  40  is biased toward the closed path position, the flange  62  (and griping region  64 ) facilitates readily moving the paddle  40  to open the strap path  36 .  
         [0055]    Referring to FIGS. 1 and 3, at a lower portion of the strap path  36 , below the paddles  38 ,  40 , at the strap path exit  44 , a turning element  66  directs the strap S toward the strapping head  18 . A winder  68  is positioned at the inlet of the strapping head  18 . The winder  68  is that element through which the strap S traverses, that rewinds or tensions the strap S after it is positioned around a load and the leading edge of the strap is grasped. The strap S traverses through a central, slot-like opening  70  in the winder during the feeding operation and, during the tensioning operation, the winder  68  rotates so as to pull or tension the strap S around the load. As the winder  68  rotates, it will be appreciated that it is “pulling” strap S both from the load as well as the slack box  16 , and consequently the “pulled” strap material S winds around an outer periphery  72  of the winder  68 .  
         [0056]    When the rewinding or tensioning step is complete (and after sealing the strap onto itself), the rewinder  68  must counter-rotate to position the central slot-like opening  70  along the strap path (e.g., in a straight-line path from the turning element  66  to the inlet to the feed and tension wheels indicated generally by the directional arrow at  74 ). During this counter-rotation, the strap S that was wound about the periphery  72  of the winder  68  (during tensioning) would otherwise tend to collect in regions above and below the winder  68  (as indicated at  76  and  78 ). Subsequent to this counter-rotation, the feed mode is re-instituted and strap S is pulled through the strap path  36  into the strapping head  18 . It has, however, been found that because these regions above and below the winder can be rather restricted in size and constricted (as to ingress and egress), the strap S can tend to become caught in these regions and twist or otherwise cause misfeed of the strapping machine.  
         [0057]    To this end, the present strapping machine  10  includes a region, indicated generally at  80  (i.e., toward and into the  16  slack box) into which this “loose” strap is directed during counter-rotation of the winder  68 . In order to direct the strap into this region, a biased winder arm  82  is positioned near the winder  68 , one end of which includes a roller  84  that rests or rides along the outer periphery  72  of the winder  68 . The  82  arm is biased, such as by a coil spring  86 , to urge the roller  84  into contact with the strap wound on the winder outer periphery  72 . In this manner, as the winder  68  counter-rotates, the strap S is directed to a single region  80 , preferably below the winder  68  (toward and into the slack box  16 ), that is configured for temporarily “storing” the strap S that is unwound from the winder  68 , with reduced opportunity for tangling. Strap can thus be directed to a region  80  that has minimized restrictions to provide a free-flowing feed of strap material S to the strapping head  18 .  
         [0058]    As will be recognized and appreciated by those skilled in the art, the strapping head  18  is configured to feed a leading end of the strap into the strap chute  20  so that the leading end of the strap S traverses around the strap chute  20  and back to the strapping head  18 . When the leading end of the strap is received in the strapping head  18 , it is gripped, at which time the strap feed stops. The strap S is then retracted and the winder  68  is actuated to begin tensioning the strap S. During retraction (or take-up), the strap S is released from the strap chute  20  so that continued rewinding operation strips or pulls the strap S from the chute  20 . As the strap S is stripped from the chute  20 , it is pulled to and around the load such that continued rewinding tensions the strap S around the load. When a predetermined tension is reached, the winder  68  stops counter-rotation and the strap S is sealed (e.g., welded) onto itself and subsequently cut from the supply or trailing end.  
         [0059]    Referring to FIGS. 16-24, in the present strapper  10 , the strap chute  20  is formed from inner and outer movable chute walls  88 ,  90 , respectively. The inner and outer walls  88 ,  90  are radially spaced from one another to define a track, space or path, indicated generally at  92 , between the walls  88 ,  90  through which the strap S traverses. The chute  20  also includes a transverse or side wall  94  that keeps the strap S within the space  92  between the inner and outer walls  88 ,  90 . During the stripping operation, the movable chute walls  88 ,  90  are moved in a longitudinal direction (see FIG. 20) so as to essentially move the walls  88 ,  90  away from the strap S as it is stripped from the chute  20  and pulled toward the load. The strap S is stripped from the chute  20  and is pulled though a gap, indicated at  96 , that is defined between the (stationary or fixed) transverse wall  94  and the (movable) chute inner and outer walls  88 ,  90  when the walls  88 ,  90  are longitudinally moved.  
         [0060]    The inner and outer walls  88 ,  90  are mounted to one another at a plurality of corner supports  98 . The corner supports  98  maintain the walls  88 ,  90  positioned relative to one another and maintain the space (between the walls  88 ,  90 ) for the track  92 . The inner and outer walls  88 ,  90  are mounted to the chute outer housing  100  at the corner supports  98  by biased pin assemblies  102 .  
         [0061]    Stationary stripping elements  104  extend through the corner supports  98  and the inner and outer walls  88 ,  90 . The stripping elements  104  contact the strap S as the inner and outer walls  88 ,  90  are pulled away from the transverse (side) wall  94  (during the stripping operation) which urges the strap S into the gap  96  between the transverse wall  94  and the movable walls  88 ,  90 .  
         [0062]    In a present embodiment, to effect movement of the chute walls  88 ,  90 , a first torsion element  106  extends upwardly in a vertical manner between the outer chute wall  90  and the chute housing  100 . The first torsion element  106  is formed from a steel rod or like element. A pin  108  extends radially through the first torsion element  106  at an upper end thereof. A second torsion element  110  is positioned at about a top of the strap chute  20  and extends horizontally therealong. The second torsion element  110 , likewise includes a radially extending pin  112  therethrough that is configured and positioned to cooperate with the pin  108  in the first element  106 . In this manner, as the first torsion element  106  is twisted or rotated, the pin  108  likewise rotates, contacting the second element pin  112  which in turn twists and/or rotates the second element  110 . A third torsion element  114  extends along an opposite, vertical side of the strap chute  20  and likewise is adapted to cooperate with the second torsion element  110  by a radially extending pin therein  116 . A fourth torsion element  118  extends horizontally along a bottom side of the chute  20 , likewise cooperating by use of the torsion pins.  
         [0063]    Each of the torsion elements  106 ,  110 ,  114 ,  118  includes a plurality of fingers or contact tabs  120  mounted thereto. The contact tabs  120  are configured to engage and push the movable strap chute walls  88 ,  90  as the torsion elements  106 ,  110 ,  114 ,  118  are twisted. In this manner, twisting the first torsion element  106  results in twisting of the second  110 , third  114  and fourth  118  elements, the contact tabs  120  of which engage the movable chute walls  88 ,  90 , longitudinally moving the walls  88 ,  90  from the strap S. The first torsion element  106  is actuated (e.g., twisted) by a camming element  122  (see FIGS. 16-17) driven as part of the strapping head  18  operation. Those skilled in the art will appreciate and understand that there are various other configurations by which the strap chute  20  can be mounted to the machine  10  and various other configurations by which the chute  20  can be moved or displaced so as to permit the strap S to fall to and tension around the load, which other configurations are within the scope and spirit of the present invention. In one contemplated arrangement, meshing bevel gears can be mounted to the torsion elements to effect cooperative rotation of the elements.  
         [0064]    It will also be appreciated by those skilled in the art, that when the strap S is released from the strap chute  20  and as the winder  68  counter-rotates to rewind or tension the strap S, there exists the potential for the strap to “fly” out of the strap chute  20  and twist as it is pulled toward the load. In order to prevent such twisting, the present strapping machine  10  includes a plurality of brushes  124  (best seen in FIGS. 1-2 and  25   a  and  25   b ) that are positioned between the strap chute  20  and the load. These brushes  124  extend across the “stripping” path of the strap to restrict release of the strap S as it exits the strap chute  20  and is pulled toward the load. The brushes  124  are positioned such that a gap  126  is defined between the end of the brush  124  (or the end of the bristles, as indicated generally at  128 ) and the side of the strap chute (that is, the side or transverse wall  94 ). The brush  124  and gap (or overhang)  126  are configured to sequentially release the strap S from the chute  20 .  
         [0065]    Referring to FIG. 25 a , in one embodiment, the brush  124  is positioned such that the size or width of the gap  126  varies along the length L 124  of the brush  124 . That is, the brush  124  is positioned such that the gap  126  between the brush end  128  and the side wall  94  varies between a largest gap G L  where it is desired for the strap S to exit the chute  20  first and narrows to a narrowest point G N  at that location at which it is desired for the strap S to exit the chute  20  last. In this manner, the chute brushes  124  provide for sequential stripping of the strap S from the chute  20 . It has been found that this sequential stripping reduces the opportunity for the strap S to twist as it exits the strap chute  20  and is tensioned around the load.  
         [0066]    Alternately, as seen in FIG. 25 b , the brush  124  can be configured such that the length L 130  of the bristles  130  is varied along the length L 124  of the brush  124  while the gap  126  between the end of the bristles  128  and the chute wall  94  is maintained relatively constant. This too, it is believed, will provide for sequentially stripping the strap S from the chute  20  due to the varied resistance of the stiffer (shorter) bristles compared to the softer (longer) bristles. Other arrangements for sequentially stripping strap S from the chute  20  will be recognized and appreciated by those skilled in the art and are within the scope and spirit of the present invention.  
         [0067]    To provide maximum operator access to the strap path  36  and the strapping head  18  while minimizing the opportunity for an operator to access moving or driven parts of the strapping machine  10  during operation, the present strapping machine  10  includes a plurality of operator accessible doors or hatches to facilitate “light” maintenance on the strapping machine  10 , such as dislodging misfed strap or clearing debris.  
         [0068]    A first such arrangement includes one or more quick release door latches  132 , such as that illustrated in FIGS. 8-11. One such latch  132  is positioned on a door  134  that encloses the first portion of the strap path  36  and a portion of the strapping head  18 . Such a door  134  is mounted to an enclosure  136  mounted to the frame  12  at upper and lower door pintles  138 . These pintles  138  extend downwardly from an upper portion of the enclosure  136  and upwardly from a lower portion of the enclosure  136 . A lower edge of the door includes an opening into which the pintle is fitted (not shown). An upper edge  140  of the door  134  includes an elongated slot  142  extending in generally the same direction as (e.g., coplanar with) the face or plane of the door  134 .  
         [0069]    A biased latch  144  is positioned on the door  134 , within the enclosed portion (that is accessible only when the door  134  is open), which latch  144  includes a pivot pin  146 , a hinge-forming projection  148  and a release handle  150 . The latch  144  is pivoted between an open position (FIG. 10) in which the hinge-forming projection  148  is moved out of the door slot  142  and a closed position (FIG. 11) in which the projection  148  extends transverse to and across the slot  142  to essentially form a hinge opening  152  into which the pintle  138  fits. In this manner, when the latch  144  is in the closed or locked position, an enclosed opening  152  is formed around the pintle  138  to permit pivoting the door  134 .  
         [0070]    The door  134  is readily removed from the enclosure  136  by depressing the release handle  150  to move the latch  144  into the open position, thus moving the projection  148  out of the pathway of the slot  142 . The door  134  can then be slid off of the upper and lower pintles  138 , thus fully removing the door  134  from the enclosure  136 . To maintain the latch  144  in the closed position, the latch  144  is biased to the closed position by, for example, a spring  154  (shown in phantom lines in FIG. 11). Such a quick release door latch arrangement  132  is likewise used on other portions of the strapping machine  10  to provide ready access to these user-accessible parts of the strapping machine  10 .  
         [0071]    To further permit ready access to portions of the strapping machine  10 , the machine  10  includes a double-hinged slack box door  158  and head door  160 , as illustrated in FIGS. 12-15. These double-hinged doors  158 ,  160  employ a single hinge  162  that allows separate and independent functioning of the doors  158 ,  160 , one of which encloses the slack box  16  and the other of which encloses the first portion of the strap path  36  and a portion of the strapping head  18 .  
         [0072]    The single, vertically oriented piano-type hinge  162  extends between upper and lower stationary portions  164 ,  166  of the frame  12 . The slack box door  158  is mounted to one flange of the hinge  162  while the head cover door  160  is mounted to the other flange of the hinge  162 . In this manner, both doors  158 ,  160  can be opened at the same time as well as each independent of the other.  
         [0073]    In the present arrangement, the head cover door  160  includes a floating guide  168  mounted thereto. The guide  168  forms a portion of the strap path at the strapping head  18  from the winder  68  into the strapping head feed wheels (not shown). By mounting the guide  168  on the head cover door  160 , rather than as a separate element within the strapping head (which is commonly known) the strap path through the strapping head  18  is more readily accessible. The guide  168  is mounted to the cover door  160  so as to “float” and is properly positioned when the door  160  is closed by aligning pins  170  that extend outwardly from fixed structural portions (not shown) of the strapping head that align with (fit into) openings  172  in the guide  168 . An exemplary arrangement is disclosed in Haberstroh, et al., U.S. Pat. No. 6,478,065, which patent is commonly assigned herewith and incorporated herein by reference.  
         [0074]    The strapping head cover door  160  is interlocked with the feed wheel drive arrangement. In such an interlocked arrangement, a key  174  mounted on the door  160  fits into an opening in a lock  176  that is mounted to the strapping head  18 . When the key  174  is removed from the lock  176 , as by opening the door  160 , power to the strapping head feed wheels is isolated so that the feed wheels will not rotate. This provides enhanced personnel safety features to reduce the opportunity for operator exposure to rotating or driven parts.  
         [0075]    The head cover door  160 , which overlies a portion of the strap path  36  and the strapping head  18 , includes openings  178  therein through which the paddle locking pin assemblies  46  extend, and through which the winder  68  can be accessed. In this manner, the paddles  38 ,  40  can be operated and the winder  68  accessed with the head cover  160  closed in that these operations may be necessary for clearing the strap path.  
         [0076]    The door  160  also includes an opening  180  through which a strap ejection chute (not shown) extends. As will be appreciated by those skilled in the art, misfed strap can be automatically ejected from the strapping head  18  and strap refeed automatically carried out following a misfed strap. In that this operation is performed automatically and without operator intervention, it is desirable to eject the strap to an area outside of the machine. Thus the ejection chute extends outside of the machine enclosures for fully automated, continual machine operation.  
         [0077]    The present strapping machine further includes enhancements to the load carriage portions of the machine  10 . As illustrated in FIGS. 1-2 and  26 - 28 , the machine  10  includes in-feed and out-feed rollers  22 ,  24  to facilitate in feed and out feed of the load from the machine  10 . These roller sets  22 ,  24  are mounted to the strapping machine  10  in order to provide a more compact, self-standing unit.  
         [0078]    In that much of the machine  10  has been configured to reduce the overall space needed for the machine footprint, a novel arrangement for mounting the roller sets  22 ,  24  to the machine  10  is used. Each the in-feed and out-feed side roller sets  22 ,  24  are mounted to the machine  10  so as to pivot upwardly into an operating position and downwardly away from the chute  20  and the head  18  enclosure to permit ready maintenance of the machine  10 . The present arrangement includes pivot pins  182  mounted to either the roller sets  22 ,  24  or the machine frame  12  that cooperate with notched openings  184  formed in the machine frame  12  or the roller sets  22 ,  24 . The frame  12  includes upwardly extending hook elements  186  that are configured for insertion into slots  188  in the roller sets  22 ,  24 . In this manner, the roller sets  22 ,  24  are pivoted upward and are then lifted so that the hook elements  186  insert into the roller set slots  188 . The roller sets  22 ,  24  are then lowered, to lock the sets  22 , 24  onto the frame  12 . Such an arrangement is used on both the in-feed and out-feed roller sets  22 ,  24  to permit readily pivoting the roller sets  22 ,  24  outwardly, away from the frame  12  for access to the chute  20  and head  18  enclosure.  
         [0079]    Referring now to FIGS. 6 and 7, still another feature that enhances the reduced size and footprint needed for machine operation is a fully enclosed and modularized electronics/control panel  190  for automatic machine  10  operation. The panel  190  is mounted to the machine  10  as a single unit within the electronics enclosure  156 . In a present arrangement, the panel  190  is formed as a door  192  for the enclosure  156 . Quick-disconnect electrical fittings  194  are used to connect the door-mounted control panel  190  so that the entirety of the control system (e.g., the controller indicated generally at  196 ) can be carried by the panel or door  190 , for ready replacement. Preferably, the panel  190  is mounted to the enclosure  156  using a quick-release latch assembly  132  such as that illustrated in FIGS. 8-11. This arrangement provides for a readily maintainable and serviceable unit that can, if necessary, be readily replaced as needed for continued machine  10  operation.  
         [0080]    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.  
         [0081]    All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure.  
         [0082]    In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.