Abstract:
A strapping machine applies a strap diagonally across a load. The machine draws a drape of strap material at a lower edge on the front of the load to an upper edge on a rear of the load, tensions the strap material and seals abutting courses of the material to one another around the load and forms a subsequent drape of strapping material. A carriage is movable longitudinally relative to the load. Opposing reciprocating sealing heads are mounted to the carriage and move toward and away from one another. The heads are movable vertically between a position above the upper edge of the load and a position at about the upper edge of the load. A strap supply and a strap lifter is associated with each of the sealing heads. The lifters lower the drape of strap material to the lower edge of the load, and raise the drape of strap material as the carriage moves relative to the load, such that the drape of strap material is drawn toward the upper edge of the opposite side of the load. The sealing heads then tension the strap material around the load and form a seal of strap around the package and a seal forming the subsequent drape of strap material.

Description:
CROSS-REFERENCE TO RELATED APPLICATION DATA 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/313,989, filed Mar. 15, 2010. 
     
    
     BACKGROUND 
       [0002]    Strapping machines are in widespread use for applying strap, such as a plastic strap material, in a tensioned loop around a load. In a typical automatic or semi-automatic strapping operation, strap is applied in either a vertical or a horizontal orientation around a load. 
         [0003]    One type of strapper uses a chute, through which strap is pushed to create a loop, which is then pulled and tensioned, and subsequently sealed around a load. Another type of strapper is a drape-type strapper in which strap is fed from opposing dispensers and joined or sealed to form a drape, which is then pulled around a load and centrally sealed and severed from the feed, while at the same time forming a central seal for a subsequent strap drape. Both the chute-type and drape-type strappers function in either a horizontal or a vertical application. 
         [0004]    Certain loads, however, require that the strap is applied in a diagonal manner, e.g., corner to corner, across a face or side of the load. This may be the case for cube-configured loads, multi-tiered loads and the like, which require stabilizing as well as bundling, for example, for shipping, handling and merchandizing. This configuration will be well recognized from a visit to any of today&#39;s “big box” wholesalers or retailers. 
         [0005]    Current diagonal strapping operations are carried out manually. An operator manually positions the strap material around the load, across a lower edge, corner-to-corner, crossing the side faces of the load to an upper corner opposite the lower corner. The strap material is then tensioned and sealed using a manual or powered tool or tools. 
         [0006]    While this method functions well to diagonally strap a load, it is time consuming, slow, labor intensive and costly. 
         [0007]    Accordingly, there is a need for a strapping machine that can be used to apply strap material to a load in a diagonal orientation. Desirably, such a machine automatically positions a load for strapping, carries out the strapping operation and repositions the load, again, automatically, for applying a subsequent strap around the load. 
       BRIEF SUMMARY 
       [0008]    Various embodiments of the present disclosure provide a strapping machine for applying a strap diagonally across a load. The strapping machine is configured to draw a drape of strap material diagonally around the load from a lower edge of the load to an upper edge on an opposite side of the load, tension the drape of strap material around the load and seal abutting courses of the strapping material to one another around the load and form a subsequent drape of strapping material. 
         [0009]    The strapping machine includes a carriage movable longitudinally relative to the load and opposing reciprocating sealing heads operably mounted to the carriage and movable toward and away from one another. The sealing heads are movable vertically between a position above the upper edge of the load and a position at about the upper edge of the load. 
         [0010]    A strap supply is associated with each of the sealing heads for supplying strap to their respective sealing heads. Strap from the strap supplies are sealed to one another to form the drape of strap material. A strap lifter is also associated with each of the sealing heads. The strap lifters are operably mounted to the carriage and capture the drape of strap material. 
         [0011]    The lifters lower the drape of strap material to the lower edge of the load, and then raise the drape of strap material as the carriage moves relative to the load such that the drape of strap material is drawn toward the upper edge of the opposite side of the load. The sealing heads then move toward one another to tension the drape of strap material around the load and to form a seal of the strap around the package and a seal to form the subsequent drape of strap material. 
         [0012]    In an embodiment, the strapping machine includes an archway and the carriage is formed as part of the archway. The sealing heads and strap lifters are operably mounted to the archway. 
         [0013]    The strapping machine defines a conveyance path and the archway is movable longitudinally along the conveyance path. The archway is movable forward and rearward along the conveyance path during a strapping cycle. 
         [0014]    The conveyance path includes a conveyor for moving the load into a strapping region at which the drape of strap material is sealed around the load. A turntable/lift can be used to position the load for strapping and can rotate the load to permit applying strap diagonally around all of the lower to upper corners. The strapping machine and turntable/lift are disposed within the conveyor. 
         [0015]    In one embodiment, a method for applying strap diagonally around a load includes engaging a drape of strap material with a lower edge of a first side of the load, drawing the drape of strap material upward and toward an upper edge on a third side of the load, opposite the first side, tensioning the drape of strap material along the upper edge on the third side of the load, and sealing the drape of strap material to itself to strap the load and form a subsequent drape of strap material. 
         [0016]    In one embodiment, the method can further include rotating the load and applying a strap from a lower edge of a third side of the load adjacent to the first side of the load, to an upper edge on a fourth side of the load, opposite the third side of the load, tensioning the strap material around the load and sealing abutting courses of the strap material to strap the load and to form a subsequent drape of strap material. In a such an embodiment in which the load is rotated, the load can be rotated 90 degrees. Alternately, the load can be rotated 180 degrees. 
         [0017]    In one embodiment, four straps are sealed around the load, each strap extending from a lower edge of a respective face to an upper edge of an opposing face, such that four straps extend around each lower edge to an opposing, respective upper edge of the load. 
         [0018]    These and other features and advantages of the present disclosure will be apparent from the following detailed description, in conjunction with the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a side view of an exemplary strapping machine for diagonal strapping of loads; 
           [0020]      FIG. 2  is a front view of the strapping machine of  FIG. 1 ; 
           [0021]      FIG. 3  is a top view of the machine; 
           [0022]      FIG. 4  is a front view of the strap lifter assembly of the machine; 
           [0023]      FIG. 5  is a side view of the strap lifter; 
           [0024]      FIGS. 6A and 6B  illustrate exemplary strapping heads used with the present strapping machine; 
           [0025]      FIG. 7  illustrates the two strap seals and the loop and drape formed by the strapping heads of  FIGS. 6A and 6B ; 
           [0026]      FIGS. 8A-8D  illustrate, schematically, the strapping of a load, and the concurrent forming of the strap drape; 
           [0027]      FIGS. 9A-9C  illustrate the movement of the machine along the conveyor from the home position to the strapping position; and 
           [0028]      FIGS. 10A-10D  illustrate the strap material positioned on the load at the first through fourth strap cycles. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    While the disclosed apparatus is susceptible of description in various forms, there is shown in the drawings and will hereinafter be described an exemplary embodiment with the understanding that the present disclosure is to be considered an exemplification of disclosure and is not intended to be limited to the exemplary embodiment illustrated. 
         [0030]    Referring to the figures and in particular to  FIG. 1 , there is shown an embodiment of a strapping machine  10  for the diagonal strapping of loads. Such a strapping machine  10  (sometimes referred to herein as “strapper” or “diagonal strapper”) uses a drape-type of operation in which a band of strap material S is draped across an edge of the load L (for example, a lower front edge LFE) and along the transverse adjacent (side) surfaces C of the load L. The strap is then tensioned and joined, as by sealing, across the diagonal (upper rear) edge URE (see, e.g.,  FIG. 10A ) by a pair of reciprocating heads  12   a,b  (see  FIGS. 6A and 6B ) having clamp and weld functions. It will be appreciated by those skilled in the art that although the present disclosure references straps, and the application of strap material to a load, other materials are well applied using the present strapping or bundling machine and method, such other materials including, but not limited to, cord, foil, cotton and the like, and that such other materials and methods are within the scope and spirit of the present disclosure. 
         [0031]    The heads  12  move toward one another, capturing and tensioning the strap S as they converge. The joining or sealing and cutting functions are then carried out to effect two seals w i , w 2  (see  FIG. 7 ); a first seal w i  seals the strap S around the load L and a second seal w 2  forms a subsequent drape portion D of strap S. The seals w 1 ,w 2  can be formed in a variety of ways, for example, by welding or the like. It will be appreciated that although the 
         [0032]    A cut is made in the straps, between the first and second seals w 1 ,w 2 . The second seal w 2 , at the cut, forms the strapped load and separates the strap S on the load L from that of the subsequent drape D. In operation, the cutting function can be carried out before, contemporaneous with, or after the welding functions. Cutting can be carried out by a physical cutting, e.g., by a blade or cutter, heat, or by any other method to form a separation in the strap. An exemplary strapping machine and strapping head configuration and operation are disclosed in van Ottele, U.S. Pat. Nos. 4,782,648 and 6,021,711, which patents are incorporated herein by reference. The Otelle patents and the present disclosure reference the use of a heat seal or weld of the strap material. It will, however, be understood by those skilled in the art that other ways in which to join the strap, such as ultrasonic seals, friction seals, adhesives such as glue, hot air, and the like are also contemplated and are within the scope and spirit of the present disclosure. 
         [0033]    The illustrated diagonal strapper  10  uses a modified reciprocating head  12  configuration along with a moving archway  14 , a conveyor  16 , a turntable-lift assembly  18  and strap lifters  20  to carry out the diagonal strapping of loads L. The diagonal strapping described below is carried out from a lower front edge LFE of the load L to an opposite upper rear edge URE of the load, thus diagonal across the side faces C of the load L. Although not described in the present disclosure, corner elements  21  may be used to help secure or support the straps (drape) at the corners/edges of the load. 
         [0034]    Referring briefly to  FIGS. 1-3 , the conveyor  16  is of a relatively conventional type. That is, the conveyor  16  can include multiple rollers  22 , at least some of which are driven. Alternately, the conveyor  16  can be formed from continuous belt  24  positioned around one or more driven rollers and supported by multiple (driven or passive) rollers. Other types of conveyors are contemplated and are within the scope and spirit of the present disclosure. The conveyor  16  is, of course, intended to move the load L from a receiving location, into a strapping region  26  of the strapping machine  10 , and out to a discharge location  28 . 
         [0035]    The moving archway  14  supports the strapping heads  12  and strap lifters  20 , and traverses longitudinally along the conveyor  16  (as indicated by the arrow at  30 ), moving from a position in front of the load L to the rear of the load L when the load is in the strapping region  26 . In this manner, the archway  14  moves the heads  12  and lifters  20  forward and rearward of the load L. Forward is referred to as that direction in which the load L moves through the strapping machine. Movement of the archway  14  effectively moves the location at which the strap joint is made between the lower front edge LFE and the upper rear edge URE of the load L. 
         [0036]    The heads  12  are mounted to the archway  14  above the conveyor  16 . The heads  12  are mounted so as to vertically traverse along the archway  14 . The archway  14  is mounted to a support system, which can be a rail or rail set  31 , to move the archway  14  horizontally along the conveyor  16 , to envelop the turntable  18 . 
         [0037]    The heads  12  are mounted to the archway  14  to move up, above the uppermost height of the load L and return to a height at about the upper rear edge URE of the load L (to effect the seal). The heads  12  traverse up, above the load L, to prevent interference with the load L and to prevent interference with the moving archway  14  as it traverse along the load path. The heads  12  can also be adjustably mounted so as to accommodate loads L of varying heights. It will be appreciated that the heads  12  can be configured to avoid interference with the load by moving up, above the load, by moving outwardly, away from the load, or a combination of both. 
         [0038]    The strap lifters  20 , which are also mounted to the archway  14  for longitudinal movement with the archway  14 , are configured to lift or raise the strap (drape D) from about just above the conveyor  16  to just above the heads  12 . In this manner, the lifters  20  engage and capture the strap S and extend the drape D from the lower front edge LFE of the load L up to and just beyond the upper rear edge URE of the load L for the strapping cycle to commence. The lifters  20  can be of a variety of different types of assemblies, for example, including rollers and the like, to permit ready movement of the strap S therethrough. 
         [0039]    Referring briefly to FIGS.  2  and  9 A- 9 C, the turntable lift  18  is disposed within the conveyor  16 , about midway along the length of travel of the archway  14 . The lift  18  is configured to receive the load L and lift or raise the load L off of the conveyor  16  an amount sufficient to allow the strapping process to proceed at the lower edges of the load L. As will be appreciated by those skilled in the art, the lift  18  engages the load L, at the bottom, away from (spaced from) the edges so as to not interfere with the strapping cycle. 
         [0040]    With reference to the strapping cycle generally, referring to  FIGS. 6A-6B ,  7  and  8 A- 8 D, the reciprocating heads  12   a,    12   b  are each fed from a dedicated dispenser  32   a,    32   b  and move horizontally toward and away from one another. The heads  12  capture the strap drape D as they move toward one another. The drape D is formed by a seal w 2  of the strap material fed from the respective dispensers  32   a,    32   b.  The drape D is positioned about the front F of the load L ( FIG. 8A ) and is brought around the sides C of the load, toward the rear R ( FIG. 8B ). As the heads  12  move toward one another, the drape is captured by the inward moving heads  12  and drawn across the rear R of the load ( FIG. 8C ). With the strap draped around the load L and around the heads  12 , the heads  12  meet and the strapping cycle commences. Following the strapping cycle, the heads  12   a,    12   b  return to their home position ( FIG. 8D ). 
         [0041]    As seen in  FIGS. 6A-6B  and  7 , in the strapping cycle, the two seals w 1 ,w 2  (which may be one, severed seal) are formed at the sealing heads  12 . The two seals w 1 ,w 2  are a first seal w 1  which is at the front of the load L (which loops around the load), and a second seal w 2  of the strap S that is fed from the respective dispensers  32   a,    32   b,  which continues or forms the next subsequent drape D. As the heads  12  then retract, the drape D is ready for the next subsequent strapping operation. 
         [0042]    In operation of the illustrated strapping machine  10 , a load L is moved along the conveyor  16  onto the turntable-lift assembly  18 . The turntable-lift  18  is actuated to raise the load L above (off of) the conveyor  16  to facilitate access to the lower corners and edges E of the load L. The moving (traversing) archway  14  is set to a home position, at the front F of the load L, with the lifters  20  supporting the strap S at the upper elevation and with the strapping heads  12  raised above the load  12 . Again, it will be appreciated that the head can be configured to move outwardly, away from the load, or configured to move both outwardly and upwardly to avoid interference with the load. 
         [0043]    The lifters  20  then lower the strap (drape D) so that the drape D engages the lower front edge LFE of the load L. The archway  14  then traverses the length of the load L, moving from the front F of the load L to the rear R of the load L. At the same time, the lifters  20  raise the strap S from the lower front edge LFE to a height above the upper rear edge URE of the load L (again, at the rear R of the load L). In that the archway  14  traverses from the front F to the rear R of the load L, the strap S is drawn at a diagonal from the lower front edge LFE to the upper rear edge URE, as seen from the side of the load L (see  FIG. 10A ). 
         [0044]    Once the archway  14  completes traversing the length of the load L, the strapping cycle commences. The reciprocating heads  12  first move downward, from the home position to a position at about the height of the upper rear edge URE of the load L. The heads  12  then move toward one another with the strap drape D captured around each head  12   a,    12   b.  Inward movement of the heads  12 , with the captured strap S, tensions the strap S and, when the heads  12  meet, the sealing (welding) and cutting cycle begins. 
         [0045]    In the welding and cutting cycle, as described in the aforementioned patents to van Otelle and as described above, two seals w 1 ,w 2  are created, one seal w 1  sealing the loop around the load L, and the second seal w 2  creating the subsequent drape D. The straps S are cut between the seals w 1 ,w 2  to separate the straps&#39; feed, and create the strap drape for the subsequent load. 
         [0046]    The lifters  20  maintain the drape D in the elevated position and the machine  10  is returned to the home position with the heads  12  raised above the load L, and the archway  14  is returned to the front F of the load L. The load L is then rotated, for example 90 degrees, by the turntable  18 . With the strapper  10  returned to the home position, and the load L rotated, the lifters  20  lower the drape D to the lower front edge LFE of the load L and the strapping sequence commences once again. In a preferred operation, four (4) straps S 1 -S 4  are positioned so as to diagonally cross all of the faces C of the load (see  FIGS. 10A-10D ). 
         [0047]    Once the strapping operation is complete, with all sides strapped, the load lift portion of the turntable-lift  18  is actuated to lower the load L, the load L is moved along the conveyor  16  to a subsequent, downstream operation and a next subsequent load is moved into place on the turntable  18 . 
         [0048]    It will be appreciated that although the operation is described with four straps S 1 -S 4  encircling the load L, one, two or three straps can be positioned around the load, and multiple straps can be positioned over one another as well, as desired. It will also be appreciated that the sequence of strapping can be carried out in a wide variety of ways. For example, once a strapping sequence is completed, the load can be rotated 90 degrees to effect the next strapping of the load, and again, between the second and third straps, the load can be rotated 90 degrees in the same direction, so as to make four 90 degree stops. Alternately, the load can be rotated 180 degrees between the first and second straps, and then 90 degrees from the second to the third, and again 180 degrees between the third and the fourth. 
         [0049]    All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure. 
         [0050]    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. 
         [0051]    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 disclosure. 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.