Abstract:
A strapping machine configured to feed a strapping material around a load, position, tension and seal the strapping material around the load, the strapping machine including a strap chute for carrying the strap around the load and for releasing the strap material from the strap chute. The strap chute defines a longitudinal axis transverse to the chute. The strap chute is formed having a chute frame and an inner wall defining a track for conveying the strap through the strap chute. The inner wall is movable relative to the chute frame, parallel to the longitudinal axis between an operating position and a release position to release the strap from the strap chute. A drive assembly is operably connected to the inner wall for moving the inner wall between the operating and release positions. The drive assembly includes driven elements mounted to the inner wall for longitudinal movement therewith. The driven elements constrain movement of the inner wall in a direction transverse to the longitudinal direction. The drive assembly includes at least two spaced apart drive members operably connected to the inner wall and configured for movement transverse to the longitudinal direction and transverse to the movement of the inner wall.

Description:
CROSS REFERENCE TO RELATED APPLICATION DATA  
       [0001]    This application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 60/479,231, filed Jun. 17, 2003. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention is directed to an improved strapping machine. More particularly, the present invention is directed to a strapping machine having an improved system that includes a track for releasing the strap from the chute.  
           [0003]    Strapping machines are in widespread use for securing straps around loads. One type of known strapper includes a strapping head and drive mechanism mounted within a flame. A chute is mounted to the flame, through which the strapping material is fed.  
           [0004]    In a typical stationary strapper, the chute is mounted at about a work surface, and the strapping head is mounted to a horizontal portion of the chute, below the work surface. The drive mechanism is also mounted below the work surface, near to the strapping head. The drive mechanism “pulls” or feeds strap material from a source, such as dispenser into the machine. The drive mechanism urges or feeds the strap through the strapping head, into and around the chute, until the strap material returns to the strapping head. The drive mechanism also retracts the strap material to tension the strap around the load.  
           [0005]    During the retraction or tensioning portion of the strapping cycle, the strap material must be released from the chute. A typical chute includes inner and outer walls that define a pathway around which the strap is fed. The inner wall (that wall closest to the load), is generally movable so that as the strap is “pulled”, the inner wall moves out of the way (from between the strap and the load), and the strap thus tensions around the load. In some configurations, the inner and outer walls are formed from a plurality of wall sections.  
           [0006]    Known chute systems use a plurality of pins, generally located at about the corners of the chute, along with springs and torsion bars to locate and move the wall out of the strap path. While these known systems function well for their intended purposes, it is necessary to assure precise alignment of the pins, over the springs, and generally through openings in the walls or flanges that are formed as part of the walls. In addition, the torsion bars must all be configured so that the walls move in a predetermined sequence, a precise distance, to release the strap.  
           [0007]    It has also been found that it is often necessary to access the strapping head (and more specifically the weld head) by removing portions of the work surface. This may be necessary to dislodge misfed strap, to clear the strapping head or weld head, or for general maintenance or repair of the machine. Quite often, it is necessary to access the strap path (by moving the strap chute) at the weld head.  
           [0008]    In known strapping machines, to access the strap path it was necessary to move the strap chute by some manual means. For example, known machines include doors or panels that require removal to access these areas of the machine. Others include sprung or biased doors that are biased closed and thus must be held open to access these machine areas.  
           [0009]    The strapping or welding head provides a number of functions. First, the strapping head includes a gripper for gripping the strap during the course of a strapping operation. The strapping head also includes a cutter to cut the strap from a strap source or supply. Last, the strapping head includes a sealer to seal a course of strapping material onto another course of material. This seal is commonly referred to as a weld and is effected by heating the overlying courses of the strap. One known heating method is the use of an electrically heated element, referred to as a weld blade or hot blade that is applied to facing sides of overlying courses of strap material. During machine operations, it has been observed that the weld blade can require cleaning fairly often (cleaning is typically carried out by lightly rubbing with an abrasive such as emery cloth).  
           [0010]    In known strapping machines, the weld blade is fixed to the strapping head as by fastening to a support. In order to inspect or maintain the weld blade, a multitude of fasteners, such as screws and bolts must be removed from the weld head and support and the blade removed from the head. This can be quite time consuming particularly if, as often happens, the weld blade requires frequent cleaning.  
           [0011]    Many such machines are employed in processes that maximize the use of fully automated operation. To this end, machines are configured for automated in-feed and out-feed, such that a load (to be strapped) is automatically fed into the machine by an in-feed conveyor, the strapping process is carried out, and the strapped load is automatically fed out of the machine by an out-feed conveyor. The in-feed and out-feed conveyors are fitted onto the machine at the work surface at either side of the strap chute. Often, the conveyors form a part of the work surface. In this manner, the in-feed conveyor receives the load and moves it into the chute area, the load is strapped and the out-feed conveyor moves the load out of the chute area.  
           [0012]    The conveyors can require maintenance on a more frequent basis than the strapper. In addition, in that the conveyor is a load-bearing surface, it may be subjected to additional stresses beyond those to which the machine, generally is subjected.  
           [0013]    In addition, as with many process equipment items, strappers are typically manufactured having a predetermined height above the floor at which the work surface is set. However, in that the strapper may be incorporated into other processes or may be used in an area where the strapper work surface height is critical, it may be necessary to vary the height of the strapper. Known machines have no “easy” way to make such height adjustments.  
           [0014]    Accordingly there is a need for an improved strapping machine that promotes ready operation and maintenance. Desirably, such a strapping machine includes an improved chute opening assembly and chute track system. More desirably, such a machine includes a pivoting weld blade that facilitates “tool-less” access to the blade. More desirably still, such a machine includes lift-off fully automatic in-feed and out-feed conveyors, and a novel height adjustment system. Most desirably, such a machine includes provisions for readily adjusting the height of the machine work surface.  
         BRIEF SUMMARY OF THE INVENTION  
         [0015]    A strapping machine of the type configured to feed a strapping material around a load, position, tension and seal the strapping material around the load includes an improved chute release system. The strapping machine includes a machine frame, a work surface for supporting the load in the strapping machine and a strap chute for carrying the strap around the load and for releasing the strap material from the strap chute. The strap chute defines a longitudinal axis transverse to the chute.  
           [0016]    The machine further includes a feed assembly that is configured to convey the strap around the strap chute in a feed mode and to retract and tension the strap around the load during a tensioning mode. During the tensioning mode, the strap is released from the strap chute and pulled around the load. A weld head welds the strap material to itself.  
           [0017]    The strap chute is formed having a chute frame and an inner wall defining a track for conveying the strap through the strap chute. The inner wall is movable relative to the chute frame, parallel to the longitudinal axis between an operating position and a release position to release the strap from the strap chute. The strap chute includes a release system having a drive assembly operably connected to the inner wall for moving the inner wall between the operating and release positions.  
           [0018]    In a present embodiment, the drive assembly includes driven elements or rollers mounted to the inner wall for longitudinal movement with the wall. The driven elements move within elongated longitudinal slots in the frame to constrain movement of the inner wall in a direction transverse to the longitudinal direction. At least two spaced apart drive members, preferably drive bars, are operably connected to the inner wall. The drive bars are configured for movement transverse to the longitudinal direction and transverse to the movement of the inner wall.  
           [0019]    In a present embodiment, the rollers extend from the inner wall, through the longitudinal slots in the frame and through elongated inclined slots in the drive bars. As such, longitudinal movement (e.g., up and down movement) of the drive bars is transferred, by movement of the rollers in the slots, into longitudinal movement of the inner wall. This, in turn, permits release of the strap from the chute.  
           [0020]    In addition to the controlled, positive release of the strap, the present release system constrains movement of the inner wall in any direction other than longitudinal, and constrains movement drive bars in any direction other than transverse (e.g., up and down), to better control strap release.  
           [0021]    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  
       [0022]    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 drawings, wherein:  
         [0023]    [0023]FIG. 1 is a perspective view of an exemplary strapping machine illustrating an automatic chute track opener system embodying one aspect of the present invention;  
         [0024]    [0024]FIG. 2 is an enlarged, partial view of the automatic chute opening system illustrated with the automatic opening contact arm resting on the (opening) work surface or conveyor section;  
         [0025]    [0025]FIG. 3 is an enlarged perspective view of the chute opening system with the contact arm shown in the open orientation and the work surface fully lifted or pivoted upwardly;  
         [0026]    [0026]FIG. 4 is a perspective view of the strapping machine chute opening system and chute track system showing the opening system moving toward the closed position;  
         [0027]    [0027]FIG. 5 is a perspective view similar to FIG. 4 with the opening system moving toward the open position;  
         [0028]    [0028]FIG. 6 is an enlarged view of the contact arm and showing the linkage between and interaction between the contact arm and the chute track system with the contact arm (and track system) moving toward the closed position;  
         [0029]    [0029]FIG. 7 is a view similar to FIG. 6 with the contact arm moving toward the open position;  
         [0030]    [0030]FIG. 8 is an enlarged partial view of the strap chute at the working surface, opposite of the welding head, and showing the cam arrangement for moving the chute for strap release (with the chute shown in the closed or operating position);  
         [0031]    [0031]FIG. 8A is a cross-sectional view taken along line  8 A- 8 A of FIG. 8;  
         [0032]    [0032]FIG. 9 is a view of the strap chute at the working surface similar to FIG. 8 with the chute shown in the open or release position;  
         [0033]    [0033]FIG. 9B is cross-sectional view taken along line  9 A- 9 A of FIG. 9;  
         [0034]    [0034]FIGS. 10-12 are side views, looking toward an inner surface of the chute and in partial cross-section of the work surface, showing the surface in the operating position, as it is pivoted upward, and in the fully upwardly pivoted position, and illustrating the chute track system position in each of the respective surface positions;  
         [0035]    [0035]FIG. 13 is a perspective view of an exemplary strapping machine illustrating, in part, the chute track system aspect of the present invention;  
         [0036]    [0036]FIG. 14 is a perspective view of the chute track system shown removed from the strapping machine,  
         [0037]    [0037]FIG. 15 is an exploded view of the chute track system;  
         [0038]    [0038]FIG. 16 is a cross-sectional view taken along line  16 - 16  of FIG. 15 in which the chute track is shown in the closed or operating position;  
         [0039]    [0039]FIG. 17 is a cross-sectional view as would be taken along line  16 - 16  of FIG. 15 when the chute track is in the open or release position;  
         [0040]    [0040]FIGS. 18-20 are views taken along line  18 - 18  of FIG. 14, showing the track system in the closed (operating) position in FIG. 18, as the chute track is moved toward the release position in FIG. 19, and in the open or release position in FIG. 20;  
         [0041]    [0041]FIG. 21 is a perspective view of an exemplary strapping machine illustrating the removable conveyors embodying yet another aspect of the present invention;  
         [0042]    [0042]FIG. 22 is a perspective view of the strapping machine illustrating the in-feed conveyor pivoted upwardly for removal;  
         [0043]    [0043]FIG. 23 is another perspective view of the machine showing the conveyor lifter from the machine;  
         [0044]    [0044]FIG. 24 is a side view of the machine of FIG. 23;  
         [0045]    [0045]FIG. 25 is a perspective view of the machine showing the out-feed conveyor pivoted upwardly and removed from the machine;  
         [0046]    [0046]FIG. 26 is a side view showing the out-feed conveyor removed;  
         [0047]    [0047]FIG. 27 is a side view similar to FIG. 26 illustrating the conveyor being positioned on the machine;  
         [0048]    [0048]FIG. 28 is an enlarged, partial view of the hinge and in-feed conveyor interlock;  
         [0049]    [0049]FIG. 29 is a side view showing the interlock key inserted in the interlock body;  
         [0050]    [0050]FIG. 30 is a side view illustrating the hinge assembly;  
         [0051]    [0051]FIG. 31 is a perspective view of an exemplary strapping machine illustrating the location of the pivoting welding head embodying another aspect of the present invention;  
         [0052]    [0052]FIG. 32 is an enlarged partial view of the interior of the strapping machine, showing the welding head with the blade in the operating position;  
         [0053]    [0053]FIG. 33 is a view similar to FIG. 32 showing the blade cradle leaned rearwardly to position the blade in the service (or cleaning) position;  
         [0054]    [0054]FIGS. 34 and 35 are different views of the blade in the operating position;  
         [0055]    [0055]FIGS. 36 and 37 are different views of the blade in the service position;  
         [0056]    [0056]FIG. 38 is a perspective view of the blade removed from the cradle to, for example, move the blade from the operating position to the service position;  
         [0057]    [0057]FIG. 39 is a perspective view of an exemplary strapping machine illustrating the table height adjustment assembly embodying another aspect of the present invention;  
         [0058]    [0058]FIG. 40 is an exploded view of the strapping machine of FIG. 39;  
         [0059]    [0059]FIG. 41 is a top view of the work surface showing the adjusting nuts;  
         [0060]    [0060]FIG. 42 is a cross-sectional view taken along line  42 - 42  of FIG. 41. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0061]    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.  
         [0062]    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.  
         [0063]    Referring to the figures and in particular FIG. 1, there is shown a strapping machine  10  embodying the principles of the present invention. The strapping machine  10  includes, generally, a frame  12 , a strap chute  14 , a feed assembly  16  and a weld head  18 . A controller  20  provides automatic operation and control of the strapper  10 . A table top or work surface  22  is disposed on the strapper  10  at the bottom of the chute  14 . A dispenser  24  supplies strapping material to the feed assembly  16  and weld head  18 . The feed assembly  16  is shown in part in FIG. 8 and the weld head  18  is shown in part in FIGS. 32-38.  
         [0064]    In one embodiment, the work surface  22 , as will be discussed below, is configured having in-feed and out-feed conveyors  23   a,b , respectively. That is, the conveyors  23   a,b  are formed as part of the work surface  22  and pivot upwardly and outwardly (relative to the strap chute  14 ) to provide access to the feed assembly  16  and the weld head  18 . Those skilled in the art will recognize that in order to access the weld head  18  and the strap path (indicated generally at  26 ) at the chute  14 /weld head  18  area, it is often necessary to “move” a portion of the strap chute  14  away from the weld head  18 . In known machines this requires manually moving the chute out of the way.  
         [0065]    The present strapping machine  10  includes an automatic chute opening system  28  that is operably connected to the work surface  22 . The chute opening system  28  opens the chute  14  upon upward pivoting of the work surface  22 . Referring briefly to FIGS. 10-12, there is shown a side view of the machine  10  with a portion of the work surface  22  in the closed position (FIG. 10) and as that portion of the surface  22  is pivoted upwardly (FIGS. 11-12). The chute opening assembly  28  includes a contact arm  30  that cooperates with the work surface  22  to rotate a torsion bar  32 . The bar  32  is mounted to permit rotation within housing  35  (FIGS. 8-9A). During a normal strapping cycle, the torsion bar  32  is rotated by a cam (not shown) to open the strap chute  14  through operation of the chute opening assembly  28 . The arm  30  is biased to the open position by a spring  34  that urges the arm  30  rearwardly (toward the chute  14 ).  
         [0066]    As seen in FIGS. 7 and 10- 12 , the arm  30  includes a roller  36  at the end thereof that contacts and rides along a lower surface  38  of the work surface  22 . The roller  36  assures that the contact between and movement of the arm  30  along the lower surface  38  remains smooth. Also as seen in FIGS. 10-12, when the work surface  22  is in the closed position, the contact location (as indicated generally at  40 ) of the roller  36  on the lower surface  38  is beyond the pivot point  42  for the work surface  22  (as the work surface  22  is pivoted upwardly). This provides a mechanical advantage in that the spring  34  bias of the arm  30  does not serve to urge the work surface  22  up or open when the surface  22  is fully down. Rather, because the arm  30  contacts the surface  22  on the “backside” of the pivot  42 , it actually serves to urge the work surface  22  to the closed position.  
         [0067]    Referring to FIGS. 3 and 6- 7 , the torsion bar  32  includes a linkage  44  that operably contacts the arm  30  by means of a pin (or screw)  45  that is mounted in the arm  30 . The pin  45  engages and “pushes” the linkage  44  upwardly. A chute track system  46  opens the chute  14  by action of the pin  45  upwardly urging the linkage  44 . FIGS. 6-7 illustrate the linkage  44  which includes a roller  48  (see FIGS. 14-15) that rides in an elongated slot  50  in the chute track system  46  for, as will be discussed below, moving the track system  46  between the open and closed positions. For purposes of the discussion that follows, the open position will be referred to as that position in which the chute  14  is open and the strap is allow to be pulled from or removed from the chute  14  and the closed position will be referred to as the position in which the chute  14  is “closed” for conveying the strap through the chute  14 .  
         [0068]    Referring now to FIGS. 13-20, the chute  14 , as will be recognized by those skilled in the art, defines a generally rectangular track (with rounded corners) about which the strap is conveyed. The track includes a novel release system  51  formed, in part, by a lip  52  that defines an inner wall against which the strap is guided as it moves around the chute  14  and a flange  54  that is typically formed as part of and outwardly of the lip  52 . To this end, the lip  52  and flange  54  are essentially an integral unit.  
         [0069]    The flange  54  is mounted to a frame portion  56  of the chute  14 . The flange  54  is mounted to the chute frame  56  such that it is movable relative to the chute frame  56  transverse to the direction of conveyance of the strap. In a present embodiment, the flange  54  (and chute  14 ) are mounted to the chute frame  56  by a plurality of springs  58  that bias the chute  14  to the closed position.  
         [0070]    The flange  54  includes a plurality of rollers  60  mounted thereto that extend outwardly (in a transverse direction) from the flange  54 . The rollers  60  are positioned in horizontal slots or channels  62  in the frame  56  to guide the movement of the chute  14  (i.e., the flange  54  and lip  52 ) between the open and closed positions. To assure smooth movement of the chute  14 , four rollers  60  are provided, one at about each of the corners of the chute  14 .  
         [0071]    As will be appreciated from the figures, the slots  62  in the frame  56  provide a path for moving the chute  14  forward and back (i.e., between the open and closed positions). In order to urge or drive the chute  14  forward and back, the chute track system  46  includes a pair of drive bars  64 , one each positioned at about opposite sides of the chute frame  56 . Referring to FIGS. 15 and 18- 20 , each of the drive bars  64  is positioned on a side of the frame  56  such that the bars  64  each cooperate with the chute flange rollers  60  that traverse in the frame horizontal slots  62 . The drive bars include inclined slots or channels  66  into which the rollers  60  insert. In this manner, each roller  60  engages both a transverse (or horizontal) frame slot  62  and an inclined drive bar slot  66 . The drive bars  64  are mounted to the frame  56  by pins  68  that permit up and down, reciprocating movement (relative to the frame  56 ) but restrain the bars  64  from any transverse movement.  
         [0072]    Referring to FIGS. 14-20, the operation of the chute track system  46  is relatively straightforward. It should, however, be recognized that the views as seen in FIGS. 18-20 are reversed from those of FIGS. 14-17. That is in FIGS. 14-17, movement of the chute  14  to the open position is shown by the directional arrow at  70 , whereas that same movement in FIGS. 18-20 is in an opposite direction, as shown by directional arrow  70  in those figures.  
         [0073]    In the closed position, the drive bar  64  is down (see FIG. 18), and the chute  14  overlies the weld head  18 . In this position, the strap is conveyed around the chute  14 . When, during the course of the strapping operation, the chute  14  is moved to allow the strap to be tensioned onto the load (and also when the work surface  22  is opened as to carry out maintenance), the drive bar  64  is urged or driven in an upwardly direction. In that the drive bar  64  is constrained to move only upwardly and downwardly (by the pins  68 ), the chute rollers  60 , which are positioned in the drive bar inclined slots  66 , are urged to move both forward and up. However, in that the chute rollers  60  are constrained to move only forward and rearward (by the frame horizontal slots  62 ), the chute  14  is urged forwardly, away from the strap path  26 . This releases the strap from the chute  14 , and opens the path  26  (e.g., moves the chute  14  to the open position). As set forth above, the chute  14  is biased to the closed position, and, as such, once the driving force (for moving the drive bars  64  to the open position) is removed, the bars  64  and the chute  14  return to the closed position.  
         [0074]    Referring now to FIGS. 18-20, and as can be seen in FIGS. 14 and 15, a lower part  72  of the drive bar  64  includes a slotted opening  50  that is operably connected to the contact arm linkage  44 . The roller  48  that is mounted to the linkage  44  rides within the slotted opening  50 . As such, as the linkage  44  moves up and down, it provides the driving force for movement of the drive bar  64 . Thus, when the work surface  22  is opened, as the contact arm  30  moves up, the linkage  44  imparts a likewise upward movement to the drive bar  64  to open the chute  14 . As will be appreciated by those skilled in the art, this upward movement is also provided during regular strapper operation when the strapper  10  cycle is at that point at which the strap is released from the chute  14  by movement of the chute  14  to the open position.  
         [0075]    Advantageously, the present strapper  10  includes removable or lift-off conveyors  23   a,b . As seen in FIGS. 21-30, the in-feed and out-feed conveyors  23   a,b  (which are configured as part of the work surface  22 ) are mounted to the machine frame  12  by hinge pins  78  (see FIGS. 28 and 30) that include a pin portion  80  and a centering flange  82  mounted to the end of the pin portion  80 . The pin portion  80  provides the pin or post about which the surface  22  (or conveyor  23   a,b ) rotates and the flange  82  assures that the surface  22  (or conveyor  23   a,b ) is aligned with the machine frame  12  for proper installation. The surface  22  (or conveyor  23   a,b ) includes an elongated slot  84  that extends beyond an outward edge  86  of the surface  22  or conveyor  23   a,b  that is configured for sliding onto the hinge pin  78 . As seen in FIGS. 25, 26 and  30 , the slot  84  extends downwardly when the conveyor  23   a,b  is pivoted up, so that the conveyor  23   a,b  can be lifted off of the machine  10 . And, when the surface  22  or conveyor  23   a,b  is pivoted downwardly to the closed or operating position the slot  84  is oriented “outwardly” of the surface  22  or conveyor  23   a,b . As shown in FIGS. 25-29, an interlock (having a body  89  and a key  88 ) can be provided to isolate power to the conveyor  23   a,b  when the conveyor  23   a,b  is pivoted from the operating position.  
         [0076]    A present strapping machine  10  is preferably fitted with fully automatic conveyors  23   a,b . That is, the conveyors  23   a,b  can operate to feed a load into the machine  10 , strap the load and remove the load from the machine  10 , without operator action. To this end, the conveyors  23   a,b  are preferably supplied with DC motors  90  that are small in size, light-weight and readily adapted for use with fully automated machine control systems  20 . Quick-connect electrical connectors  92  are preferably used to permit readily replacing the motors  90  to, for example, conduct maintenance or the like.  
         [0077]    Referring now to FIGS. 31-38, to further reduce machine  10  “downtime” to, for example, maintain the weld head  18 , the present machine  10  includes a pivoting weld blade  94 . Unlike known strapping machines that use a fixed mounting with threaded fasteners and the like, the present strapper  10  uses a weld blade  94  that is mounted to a slotted carrier  96  that is, in part, pivotally mounted to a blade arm  98 . Referring to FIG. 38, the blade  94  is fixedly mounted to the slotted carrier  96  which is held in place on the blade arm  98  by a spring  100 . The arm  98  includes a channel  102  that is configured to receive the carrier  96 . The carrier  96  includes a depending insert  104  that has a slot  106  formed therein.  
         [0078]    To assure that the carrier  96  is properly aligned in the arm channel  102 , two fixed pins  108 ,  110  extend through the arm  98 , across the arm channel  102 . The pins  108 ,  110  are positioned so that the carrier slot  106  fits over the pins  108 ,  110  to locate the carrier  96  on the arm  98 . In this manner, the carrier  96  (and thus the blade  94 ) is properly seated on the arm  98  when the slot  106  is fitted over the pins  108 ,  110 . The spring  100  (which extends between the carrier  96  and the arm  98 ) creates a tension that maintains the carrier  96  properly seated on the arm  98 .  
         [0079]    As seen in FIGS. 36 and 37, the two pin configuration, in addition to securing the carrier  96  in the operating position, also permits securing the carrier  96  (and blade  94 ) in a cleaning or service position in which it is accessible (i.e., leaned rearwardly and exposed) to permit, for example, cleaning the blade  94  as by wiping with an abrasive cloth or the like. The carrier  96  is maintained in the cleaning or service position by inserting the carrier  96  onto the arm  98  with the carrier slot  106  inserted over the upper pin  108  only. Again, the carrier  96  is maintained in this position by the tension exerted by the spring  100  on the carrier  96 .  
         [0080]    The present strapping machine  10  is also configured to permit readily adjusting the height of the machine  10  to fit within a pre-configured process (if, for example, the machine  10  is to operate in a fully automatic mode) or to accommodate operators of different heights. Referring to FIGS. 39-42, the machine  10  includes a pair of height adjustment assemblies  112 , each operably connecting the machine frame  12  to a leg assembly  114 . Each leg assembly  114  is formed having a generally square cornered U-shape, with a caster or wheel  116  positioned at the corners of the U-shaped element  114 .  
         [0081]    Each side of the adjusting assembly  112  (for purposes of the present disclosure, the machine  10  includes two adjusting assemblies  112 , one on each side of the machine  10 ) includes a pair of elongated threaded rods  118  that are mounted for rotation (but not threading) at the work surface  22 . Each rod  118  is threaded in to an adjusting nut  120  that is retained in the leg assembly  114 . In a present embodiment, the rods  118  are secured (for rotation) at the work surface  22  by a bronze bushing  122  and the adjusting nut  120  is a bronze nut. The nut  120  is held or retained in the leg assembly  114  by a nut retainer  124  that is affixed to the leg assembly  114 . Rotation of the rod  118  (from the top of the work surface  22 ) is facilitated by an opening in the work surface  22 , through which a hex head  126  (of the rod  118 ) is accessible (see FIG. 41).  
         [0082]    To permit the adjustment (i.e., raising and lowering) of both of the sides of each leg assembly  114  the height adjustment assembly  112  can include a sprocket  128  mounted to the bottom of each rod  118  and chain (not shown) or like linking assembly that extends between the sprockets  128  so that rotation of one of the threaded rods  118  rotates the other rod  118 . It is anticipated that such an arrangement will permit more readily and more quickly adjusting the height of the machine  10  and will permit height adjustment without twisting the machine frame  12 .  
         [0083]    To further facilitate the adjustment of the machine  10  height, the height adjustment assembly  112  includes a machine height indicator  130 . As seen in FIG. 39, the indicator  130  includes a reverse scale  132  (that is the scale  132  has the lower numbers at a higher position on the machine frame  12 ), and an opening or slot  134  in the frame  12  through which an indicating pointer  136  extends. The indicating pointer  136  is fixedly mounted to the leg assembly  114  such that as the frame  12  is raised or lowered relative to the leg assembly  114 , the height of the frame  12  relative to the leg assembly  114  is indicated by the position of the indicating pointer  136  along the scale  132 .  
         [0084]    All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure.  
         [0085]    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.  
         [0086]    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 all such modifications as fall within the scope of the claims.