Abstract:
An improved side seal strapping machine is configured to feed a strapping material around a load, position, tension and seal the strapping material around the load. The machine is configured for strapping relatively incompressible, debris laden loads. The machine includes a frame having a biased, movable carriage mounted to a side thereof, a modular sealing head mounted to the carriage and a modular feed head mounted to the carriage. A strap chute is mounted to the frame. The chute has a movable bottom chute section and a movable lower head-side section adjacent the sealing head. The movable lower head-side chute section is movable with the carriage, and the movable lower head-side chute section and the bottom section are hingedly connected to one another for cooperative movement. A passive debris ejection system includes openings formed in the bottom chute section and openings formed at junctures of the bottom chute section and sections adjacent thereto.

Description:
CROSS REFERENCE TO RELATED APPLICATION DATA  
       [0001]     The application claims the benefit of priority of Provisional U.S. Patent Application Ser. No. 60/501,677, filed Sep. 10, 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 side seal strapping machine that is used to strap relatively incompressible, debris laden materials, such as bricks.  
         [0003]     Strapping machines are in widespread use for securing straps around loads. The bundling of bricks by strapping is one use for such strapping machines, and has become one of the more popular methods for bundling bricks. Due to the incompressibility of the load and the debris that is generated during the strapping operation, top seal machines are in widespread use for strapping bricks. A top seal machine is configured having the strapping head positioned at the top of the strap chute, above the load. This configuration results in tensioning tightest on the top bricks of the bundle.  
         [0004]     Although such top seal machines function quite well, there are drawbacks to these machine configurations. For example, many top sealers require a frame structure to raise and lower the strapping head so that the load can be moved into and out of the strapper (within the chute area). Such a structure can be quite large and cumbersome, adding cost, size and complexity to the overall machine.  
         [0005]     In addition, the nature of such a machine requires a chute that is moved or positioned so that the head can be moved up and down to move the load into and out of the chute area. This too adds to the complexity of the machine and increases the opportunity for a strap misfeed due to a misaligned chute.  
         [0006]     Although side seal strapping machines, generally, are known, use of these machines has not been made in the field of brick strapping due to the amount of debris that is generated that can adversely effect the strapping head and can block the strap chute.  
         [0007]     Accordingly there is a need for an improved side seal strapping machine that can be used for strapping relatively incompressible, debris laden materials, such as bricks. Desirably, such a machine includes passive debris ejection provisions for clearing the strap chute of debris. More desirably, such a machine can be used without increased structure for vertically moving the strapping head toward and away from the load when positioning the load in the strapper. Most desirably, such a machine uses modular assemblies and permits “flexing” of the strap chute, while maintaining strap path alignment.  
       BRIEF SUMMARY OF THE INVENTION  
       [0008]     An improved side seal strapping machine is configured to feed a strapping material around a load, position, tension and seal the strapping material around the load. The strapping machine can be used for strapping relatively incompressible, debris laden materials, such as bricks.  
         [0009]     The machine includes a frame having a movable carriage mounted to a side thereof. The carriage moves along a vertical shaft, and is mounted to the shaft by linear bearings. The carriage is returned to an operating position by a spring disposed about the shaft below the bearings.  
         [0010]     A modular sealing head is mounted to the carriage and a modular feed head is mounted to the carriage. A strap chute is rigidly mounted to the frame and has a movable bottom chute section and a movable lower head-side movable section adjacent the sealing head. The movable lower head-side chute section is movable with the carriage and is hingedly connected to the bottom section for cooperative movement. In a preferred embodiment, the strapping machine is configured in a tandem arrangement having a pair of side-by-side strapping heads (sealing head and feed heads) and strap chutes.  
         [0011]     A passive debris ejection system includes openings formed in the bottom chute section and openings formed at junctures of the bottom chute section and sections adjacent thereto. When strap material is fed into the strapping machine through the feed head and the sealing head, the strap is conveyed into the strap chute, and is tensioned around the load.  
         [0012]     During tensioning, the carriage, carrying the sealing head and the feed head floats and is moved downward in response to tensioning. The movable strap chute sections provide a self aligning strap path upon downward float and upward return. Debris that is generated during handling of the load is ejected from the strap chute through the openings formed in the bottom chute section and the openings formed at the junctures of the bottom chute section and sections adjacent thereto. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0013]     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:  
         [0014]      FIG. 1  is a perspective view of an assembly that includes an exemplary side seal strapping machine having a self-aligning, passive debris ejection strap chute, which strapper includes modular components;  
         [0015]      FIG. 2  is a side view of the side seal strapping machine;  
         [0016]      FIG. 3  is a perspective view of the side seal strapper looking in toward the strapping head;  
         [0017]      FIG. 4  is a partial perspective view similar to  FIG. 3 , but as seen from the opposite side from  FIG. 3 ;  
         [0018]      FIG. 5  is a perspective view of the bottom of the side portion of the chute showing the strapping head, the lower head-side/bottom chute juncture and the floating mount for the strapping head;  
         [0019]      FIG. 6  is a view of the front of the strapper (e.g., an operator&#39;s view) showing the feed and sealing head modules of one of the (two) tandem, side-by-side strapping heads;  
         [0020]      FIG. 7  is a view of the front of the strapper illustrating one set of open receiving areas for the feed and sealing head modules in the side-by-side strapping head arrangement and showing the floating head mount;  
         [0021]      FIG. 8  is a view of the module receiving areas, showing the floating head mount;  
         [0022]      FIG. 9  is a view of the feed head and receiving area, showing the feed head partially within (installed or removed from) the receiver;  
         [0023]      FIG. 10  is view of the installed feed head showing the head locked into position in the receiver;  
         [0024]      FIG. 11  is an enlarged view of looking into the receiving areas and showing one of the sealing heads and one of the feed heads in place;  
         [0025]      FIG. 12  illustrates a clamping arrangement for maintaining the sealing head in place in the receiver;  
         [0026]      FIG. 13  is side view chute system showing the sealing and feed head carriage, and further illustrating the “floating” connection between the lower head-side chute section and the bottom chute section, and further illustrating a portion of the passive debris ejection system, and an internal chute guide for directing the strap over the debris ejection opening;  
         [0027]      FIG. 14  is a view taken along line  14 - 14  of  FIG. 13 ;  
         [0028]      FIG. 15  is a perspective view of the strap chute;  
         [0029]      FIG. 16  is a perspective view of the bottom chute portion illustrating the floating and fixed pivots;  
         [0030]      FIG. 17  is a top view of the bottom chute portion illustrating portions of the passive debris ejection system and the chute portion showing the slotted pivot;  
         [0031]      FIG. 18  is a side view of the chute alignment system showing the “floating” connection between the lower head-side chute section and the bottom chute section;  
         [0032]      FIG. 19  is a side view of the bottom chute section showing the passive debris ejection system, in part, in phantom lines;  
         [0033]      FIGS. 20 and 21  are cross-sections taken along lines  20  and  21 , respectively, in  FIG. 19 ;  
         [0034]      FIG. 22  is a perspective view of the floating connection between the lower head-side chute section and the bottom chute section; 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0035]     While the present invention is susceptible of embodiment in various forms, there is shown in the figures 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.  
         [0036]     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.  
         [0037]     Referring to the figures and in particular to  FIGS. 1-2 , there is shown a side seal strapping machine  10  embodying the principles of the present invention. The illustrated strapping machine  10  is configured with side-by-side or tandem modular strapping heads  12 . That is, the strapping machine  10  includes side-by-side strapping heads  12 , where strapping head  12  refers, generally, to a feed head  14  and a sealing head  16 , collectively. The modular components are as described in Flaum et al., U.S. Pat. No. 6,584,892, which patent is commonly assigned with the present application and is incorporated herein by reference.  
         [0038]     The strapping machine  10  includes generally, a frame  18 , a pair of strap chutes  20 , the pair of strapping heads  12 , a strap supply or dispenser (not shown) and a control system  22 . It is to be noted that the strapping heads  12  are independent of one another, such that either or both of the strapping head  12  subsystems can be operated at any given time. To this end, the chute  20  systems and control systems  22  are independent of one another as well.  
         [0039]     The feed head  14  is that assembly within the strapping machine  10  that conveys the strap material S (see, e.g.,  FIG. 6 ) through the sealing head  16  and into the chute  20 . The strap material traverses through the chute  20  back around to the sealing head  16 . In the illustrated machine  10 , the strap is conveyed downward from the feed head  14 , through the sealing head  16 , toward the bottom portion  24  of the chute  20 . The strap continues upwardly around the far side  26  of the chute  20 , across the top  28  of the chute  20  and back to the sealing head  16 .  
         [0040]     Upon return to the sealing head  16 , the strap is gripped by a gripper (not shown) in the sealing head  16 . The feed mechanism  14  then reverses to tension the strap. The head  16  floats downward in response to strap tensioning. When a desired tension is achieved, the tensioned end of the strap is gripped and the strap is cut to separate the strap from the source. The strap is welded or otherwise sealed onto itself by methods known in the art. The load is then removed from inside the chute  20  region or strap path and a new load is positioned therein for strapping.  
         [0041]     As set forth above, the present strapper  10  is unique in that it uses a side seal arrangement for strapping incompressible, debris laden material. It is further unique in that the strapper  10  carries out these functions in a unit that includes a modular component arrangement (i.e., a modular feed head  14  and a modular sealing head  16 ). The machine  10  is further unique in that the side seal arrangement provides for tensioning the strap from the bottom of the load up. This results in a tighter bottom strap which enhances package integrity. This arrangement also enables enhanced visual inspection by the operator, during operation, and further provides an ergonomic lifting position for manual removal and replacement of the heads  14 ,  16 .  
         [0042]     The modular components are as described in the above-noted patent to Flaum et al. In this arrangement, separate feed heads  14  and sealing heads  16  are independently positioned and mounted to a carriage  30  that is mounted to the strapping machine frame  18 . Referring to  FIGS. 6-11 , the carriage  30  includes a receiver region  32  having a feed head receiver  34  and a sealing head receiver  36 . The receivers  34 ,  36  are positioned with the feed head receiver  34  above the sealing head receiver  36 . In this manner, the strap is fed into the top of the feed head  14 , and is directed or fed downwardly through the sealing head  16 , into the strap chute  20 .  
         [0043]     The feed head receiver  34  includes a support plate  38  on which the head  14  rests. A lip  40  is positioned about the periphery of the plate  38  to prevent the head  14  from inadvertently falling from the plate  38  when the head  14  is removed from the receiver  34 . The head  14  has rollers  42  mounted to the base thereof for ease of moving the head  14  into and out of the receiver  34  (for rolling the head  14  along the plate  38 ). A latch  44  is position at the top of the receiver  34  that cooperates with a latching portion, e.g., a latch bar  46  on the feed head  14 . In this manner, the head  14  locks or latches into place in the receiver  34 .  
         [0044]     The sealing head  16  is mounted to the carriage  30  at the sealing head receiver  36 . Like the feed head  14 , the sealing head  16  includes rollers  48  to facilitate readily installing and removing the head  16  from the receiver  16 . However, the sealing head rollers  48  are positioned at about an upper region of the head  16  so that the head  16  “hangs” as it is supported by the rollers  48 .  
         [0045]     The sealing head receiver  36  includes an upper plate  50  (from which the head  16  hangs) that includes a notch  52  formed therein. The head  16  includes a clamp  54  that locks the head  16  to the plate  50 . In a present arrangement, as disclosed in the above-noted patent to Flaum et al., the clamp  54  is a hand-tightened element, such as a threaded stud  56  (having a handle  58 ) that threadedly engages or tightens onto the plate  50  when the stud  56  is positioned in the notch  52 .  
         [0046]     Referring to  FIGS. 6-8 , the carriage  30  is mounted to the frame  18  by linear bearings  61  riding along a shaft  60 . A biasing element  62 , such as the illustrated coil spring, is disposed about the shaft  60 , below the bearings  61  to provide a counterbalance arrangement for the heads  12  and carriage  30 . It will be appreciated that during the strapping cycle, as the strap is tensioned about the load (bundle of bricks), the act of tensioning the strap tends to compress the load and to drive the tensioning element in the direction of the tensioning force. In this case, the tensioning element is, collectively, the strapping head  12  which includes the feed head  14 . In that the load is substantially incompressible, the tendency is to create a greater driving force to drive the tensioning element (or head  12 ) downward.  
         [0047]     The floating mount permits movement of the head  12  (by movement of the carriage  30 ) downward. In this manner, as the strap is tensioned, rather than over-tensioning the strap, the head  12  “floats” downward (along the shaft  60 ) toward the floor. After sealing of the strap and releasing of the grippers (not shown, but within the heads  12 ), the head  12  (carriage  30 ) is returned to its normal operating position by the spring  62  force. Those skilled in the art will appreciate that cylinders or other devices/assemblies can be used to return the carriage  30  to its operating position.  
         [0048]     Referring to  FIGS. 2-5  and  13 - 22 , the strap chute  20  surrounds the load as the load is positioned in the machine  10 . As illustrated, the strap chute  20  is formed as a generally rectangular channel through which the strap traverses. For purposes of the present description, the chute will be viewed as having four separate sections, namely, the bottom portion or section  24 , the far side section  26 , the top section  28  and a near side or head-side section  64 . The head-side section  64  is further divided into an upper head-side section  66  and a lower head-side section  68  with the sealing head  16  disposed between the upper and lower head-side sections  66 ,  68 . Transition sections  70 ,  72  are disposed between the top section  28  and the far side section  26  and between the top section  28  and the upper head-side section  66 . Likewise, transition sections  74 ,  76  are disposed between the bottom  24  and far side section  26  and the bottom  24  and lower head-side section  68 .  
         [0049]     The strap chute sections are either fixed (far side section  26 , top section  28  and upper head-side section  66 ) relative to the strapping heads  12  or float (lower head-side section  68  and bottom section  24 ) along with the strapping heads  12 . The fixed sections are fixedly mounted to the frame  18 . The floating sections float by virtue of attachment to the carriage  30  or to one another. In this manner, floating of the heads  12  is accommodated by or accounted for by movement of the strap chute sections  24  and  68  with the heads  12 , while at the same time, taking into account the necessity of maintaining gaps (as indicated at  78 ) between the strap carrying components (e.g., between the head  16  and the lower head-side section  68 ) as small as possible to maintain control and direction of strap conveyance though the chute  20 . That is, if the lower head-side section  68  was not designed to float along with the strapping head  12 , the gap between the strapping head  12  and the lower head-side section  68  would have to be large enough to accommodate movement of the head  12  as it floats. This, however, would result in a gap that is so large (during strap feed) that the opportunity to misfeed strap would be greatly increased.  
         [0050]     The lower head-side section  68  is fixedly mounted to the carriage  30 . In this manner, as the carriage  30  moves up and down, the lower head-side section  68  likewise moves up and down. This permits the lower head-side section  68  to be mounted sufficiently close to the head  16  (i.e., with minimal gap) to reduce the opportunity for strap misfeed, yet contain adequate size debris openings.  
         [0051]     The bottom section  24  is pivotally mounted to the lower head-side section  68  and the far side section  26 . More specifically, the bottom to far side transition  74  is fixedly mounted to the far side section  26 , and as such the bottom section  24  is movably mounted to that transition section  74 . Likewise, the transition  76  between the lower head-side section  68  and the bottom section  24  is fixedly mounted to the lower head-side section  68  and as such, the bottom section  24  is movably mounted to that transition  76  section, as well.  
         [0052]     To accommodate the movement of the bottom section  24 , pivot mounts  80 ,  82  are positioned at each of the bottom section  24  to transition  74 ,  76  junctures. The pivot mount  80  at the bottom section  24  to far side transition  74  is a fixed pivot. That is, it is a conventional rotating pivot. The pivot  82  at the bottom section  24  to lower head-side section transition  76 , on the other hand, is a floating pivot. As seen in  FIGS. 16 and 18 - 22 , a pivot pin  84  floats in an elongated slot  86 . This configuration permits an additional degree of freedom of movement (e.g., linear as well as rotational) to accommodate movement of the lower head-side section  68  due to strapping head  12  float. The pivoting connections of the bottom chute section  24  to the far side  26  and lower head-side  68  chute sections provide for self alignment of the chute sections  24 ,  26 ,  68  upon return of the carriage  30  (heads  12 ) to the operating position after downward float and upward return. It will be appreciated by those skilled in the art that the locations of the fixed and floating pivots can be reversed (that is locating the fixed pivot at the lower head-side section transition and locating the floating pivot at the far side transition), and that such an alternate arrangement is within the scope and spirit of the present invention.  
         [0053]     Another important advantage of the present chute  20  system is the passive debris ejection feature. Referring to  FIGS. 13 and 17 - 22 , debris ejection is provided by an open slotted bottom chute section  88  and partially open bottom transition sections  90 ,  92 . The open slotted bottom section  88  is formed as a plurality of spaced guide elements  94  with openings  96  between the elements  94  to permit debris to “fall” from the chute  20  through the openings  96 . The elements  94  have upwardly inclined guide surfaces  98  that maintain the strap within the chute  20  as the strap is conveyed along the chute  20 . The inclined surfaces prevent the strap from inadvertently or improperly exiting the chute  20  between the guide elements  94 .  
         [0054]     The open bottom transition sections  90 ,  92  likewise provide an egress for debris that might otherwise become lodged in and clog the chute  20 . The open bottom areas  90 ,  92  are large and are configured to permit the free flow of debris from the chute  20 .  
         [0055]     Turning guides  100 ,  102  are positioned to assure that the strap is properly directed or conveyed around the “corners” where the bottom section  24  to side sections  26 ,  68  are open. The turning guides  100 ,  102  provide a surface from which the strap can “jump” from one section to the next. As can be seen in  FIG. 19 , the turning guides  100 ,  102  are configured with sufficient inclination so as to direct the strap along the “landing site” (of the bottom section  24  or the bottom to far side transition  74 ) downstream of the leading edge of the landing site. Advantageously, this arrangement maintains the strap within the chute  20 , again preventing the strap from inadvertently or improperly falling through the open corners  90 ,  92 .  
         [0056]     Other features of the machine  10  include a pair of strapping head guards  104  ( FIGS. 4 and 5 ), one each associated with a respective strapping head  12 . The guards  104  are positioned about the heads  12  and the upper and lower head-side chute sections  66 ,  68 . The guards  104  are replaceable to provide a replaceable wear surface and to protect the heads  12  from damage by a load as the load is moved into or out of the chute  20 .  
         [0057]     In operation, strap is fed into the strapping machine  10  and enters at about the top of the feed head  14 . The strap is directed downward, through the feed head  14 , into the sealing head  16  and the lower head-side chute section  68 . The strap is directed by the turning guide  100  into the bottom chute section  24  and continues across the bottom section  24  to the turning guide  102  to transition into the far side section  26 . The strap continues up the far side  26 , across the top section  28  and down the upper head-side section  66 , traversing back in to the sealing head  16 . Upon return to the sealing head  16 , the free end of the strap is gripped and strap feed stops. When the load is ready, the feed head  14  then reverses to tension the strap.  
         [0058]     In that the load is essentially incompressible, as slack is drawn from the strap and as the strap tension increases, the strapping head  12 , as carried by the carriage  30 , and which floats, is “pulled” downward, while at the same time the strap is pulled from the chute  20  onto the load. As this occurs, the lower head-side chute section  68  likewise floats down and the bottom chute section  24  pivots downwardly, to accommodate the float. Once the strap is tensioned around the load, the strap is sealed to itself and severed from the supply. The load can then be removed from the chute  20  area and a subsequent load positioned for strapping.  
         [0059]     As the strap is tensioned around the load (and generally, as the load is manipulated in the strapping machine  10 , particularly when the load is a brick bundle), debris is typically generated. As the debris falls from the bricks it has been observed that in prior, known strapping machine, a significant amount of the debris can fall in to the chute. This can adversely effect the operation of the strapper (clogging the chute and causing strap misfeed), and greatly increases the maintenance required. The present strapping machine  10 , with the passive debris ejection system provides for the ejection of the debris from the machine  10 , without additional moving or driven parts, and more significantly, without added machine down time.  
         [0060]     All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure.  
         [0061]     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.  
         [0062]     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.