Abstract:
A dunnage conversion machine ( 115 ), wherein sheet stock material is crumpled to form a crumpled strip, includes a feeding assembly ( 132 ). The feeding assembly ( 132 ) includes opposed feeding members that engage and advance the crumpled strip therebetween. One of the feeding members ( 141 ) includes a rotating member ( 141 ) supported on a shaft ( 144 ) for rotation about the axis of the shaft, the shaft being mounted for transverse movement toward and away from the other feeding member ( 140 ) to accommodate variations of the thickness of the crumpled strip as it is advanced between the opposed feeding members ( 140  and  141 ). The conversion machine ( 115 ) also includes a guide member ( 200 ) positioned laterally adjacent to the rotating member ( 141 ) progressively to guide a portion of the crumpled strip underneath the shaft ( 144 ). The guide member ( 200 ) has at least a portion adjacent the shaft ( 144 ) that is transversely movable.

Description:
[0001]    For purposes of the United States, this application claims the benefit of U.S. Provisional Patent Application No. 60/582,785, filed Jun. 25, 2004, which is hereby incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a dunnage conversion machine and method, and more particularly to a dunnage conversion machine having an improved feeding mechanism that resists jamming. 
       BACKGROUND 
       [0003]    Various dunnage conversion machines crumple a sheet stock material into a strip of dunnage useful as a packaging material. Exemplary dunnage conversion machines are disclosed in U.S. Pat. Nos. 6,540,652 and 6,387,029, both of which are incorporated herein by reference. 
         [0004]    Dunnage conversion machines typically include a feeding assembly that includes opposed members for engaging and advancing a crumpled strip of the stock material. Usually, one of the opposed members is a rotating member mounted on a shaft that can move transversely towards and away from the other opposed member to accommodate variations in thickness of the crumpled strip. These thickness variations can be substantial, especially when using different stock materials. The stock material can be composed of one or more plies of paper, the number of plies can be varied, and the one or more plies of the stock material can include plies with different bias weights to impart different dunnage characteristics to the strip of dunnage produced by the conversion machine. Consequently, the thickness and characteristics of the dunnage strip passing through the feeding assembly can vary significantly, which can present problems or adverse performance in known dunnage conversion machines. 
       SUMMARY 
       [0005]    The present invention provides a dunnage conversion machine that minimizes or eliminates jamming or other performance problems. In accordance with the invention, a floating guide is provided to assist in guiding the crumpled strip through the feeding assembly. The guide can move transversely to accommodate a wide variation in the thickness of the crumpled strip passing through the feeding assembly. 
         [0006]    A dunnage conversion machine provided in accordance with the present invention, wherein sheet stock material is crumpled to form a crumpled strip, comprises a feeding assembly that includes opposed feeding members that engage and advance the crumpled strip therebetween. One of the feeding members includes a rotating member supported on a shaft for rotation about the axis of the shaft, the shaft being mounted for transverse movement toward and away from the other feeding member to accommodate variations of thickness of the crumpled strip as it is advanced between the opposed feeding members. The conversion machine also includes a guide member positioned laterally adjacent the rotating member progressively to guide a portion of the crumpled strip underneath the shaft. The guide member has at least a portion thereof adjacent the shaft that is transversely movable. 
         [0007]    The guide member can include a surface that extends progressively further from the shaft. A pair of laterally spaced apart side walls define a channel that laterally constrains the stock material adjacent the rotating member, and the guide surface extends substantially the entire distance between the rotating member and at least one side wall. The guide member generally extends beyond the radial extent of the rotating member. The machine can include another guide member, and the two guide members can be mounted on axially opposite sides of the rotating member. 
         [0008]    The feeding assembly typically moves the stock material through a forming assembly that forms the sheet stock material into a relatively less dense strip of dunnage. 
         [0009]    The pair of opposed rotating members can be biased toward one another, and the shafts of the rotating members can be parallel to each other. 
         [0010]    These and other features of the invention are fully described and particularly pointed out in the claims. The following description and annexed drawings set forth in detail one illustrative embodiment of the invention, this embodiment being indicative of but one of the various ways in which the principles of the invention may be employed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0011]      FIG. 1  is a side view of the dunnage conversion machine disclosed in U.S. Pat. No. 6,387,029, with a side panel of the machine&#39;s housing nearest the viewer removed to permit viewing internal machine components, including a feeding assembly. 
           [0012]      FIG. 2  is an enlarged cross-sectional side view of a portion of a dunnage conversion machine in the vicinity of a feeding assembly provided by the present invention. 
           [0013]      FIG. 3  is a front view of the feeding assembly shown in  FIG. 2   
           [0014]      FIG. 4A-4D  are side and front views of a guide shoe for the feeding assembly provided by the present invention. 
       
    
    
     DETAILED DESCRIPTION  
       [0015]    Referring now to the drawings in detail, and initially to  FIG. 1 , an exemplary dunnage machine  15  includes a conversion assembly for converting a sheet stock material into a relatively less dense dunnage product. The conversion assembly typically includes a forming assembly  31  that forms the sheet stock material into a strip of dunnage and a feeding assembly  32  that advances the stock material through the forming assembly  31 . In the illustrated embodiment, the feed assembly  31  also connects overlapped portions of the stock material to keep the strip of dunnage from coming apart as it is manipulated. 
         [0016]    The dunnage conversion machine, or converter  15 , has at its upstream end  25  (to the left in  FIG. 1 ) a holder  16  for a supply, such as a roll, of sheet stock material. The stock material generally consists of one to three superimposed plies or layers of biodegradable, recyclable and reusable kraft paper rolled onto a hollow cylindrical tube. Other types of sheet stock material can be acceptable alternatives, including for example, other types of paper, fan-folded stock material, discrete sheets, plastic sheet material, etc. The illustrated converter  15  converts the stock material into a crumpled strip having lateral pillow portions separated by a narrow central band. The overlapping layers of sheet material in the central band are connected to form a coined strip of dunnage that can be severed, as by cutting, into sections, or pads, of a desired length. 
         [0017]    The machine  15  includes a housing  18  having a base plate or wall  20 , side plates or walls  21 , an end plate or wall  22  and a top wall  23  which collectively form an enclosed frame structure. The housing (or frame)  18  also includes a front cover or plate  26 . The end plate  22  and front plate  26  bound upstream and downstream ends of a box-like extended portion of the downstream end of the housing  18 . 
         [0018]    The machine  15  further includes a stock supply assembly  30 , a forming assembly  31 , a feeding assembly  32 , a severing assembly  33 , and a post-cutting guide assembly  34 . The stock supply assembly  30 , including a constant entry roller  36  and separators  37   a - 37   c , is mounted adjacent an upstream side of the housing  18 . The forming assembly  31  is located downstream of the stock supply assembly  30  interiorly of the housing and functions to form the stock material into a continuous three-dimensional strip of dunnage with portions of the stock material overlapped along the central region of the strip. The terms “up-stream” and “downstream” are herein used in relation to the direction of flow of the stock material through the machine  15 . 
         [0019]    The forming assembly  31  includes a shaping member  27  and a converging chute  48  that cooperate to form and crumple the stock material as it advances through the forming assembly  31 . The stock material travels between the shaping member  27  and the chute  48 , which also causes lateral edges of the stock material to turn inwardly. The dunnage machine  15  can further include a pad width adjustment device  90  ( FIG. 2 ) upstream of the feeding assembly  32  to limit the width of the strip entering the feeding assembly. Also, the forming assembly is provided with a guide ramp  47  to which the chute  48  is mounted, the guide ramp having an extended guide surface portion  49  extending from the downstream end of the shaping chute into close proximity to the feeding assembly  32 . 
         [0020]    The feeding assembly  32  in the illustrated machine performs two functions. The feeding assembly  32  connects the overlapped portions of the stock material to maintain the three-dimensional shape of the strip of dunnage. The feeding assembly  32  also advances the stock material through the machine, as by pulling the stock material from the stock supply assembly  30  and through the forming assembly  31 . In the illustrated embodiment these dual functions are carried out by a pair of opposed feeding members, including rotating members  40  and  41 . One of the members  40  is mounted on a shaft  43  rotatably driven by the feed motor whereas the other member  41  is mounted on an idler carried on a floating idler shaft  44 . The driven member  40  rotates about an axis fixed with respect to the front plate  22  whereas the idler member  41  is carried on the floating shaft which is guided by guide slots in guides  45  for parallel translating movement in a transverse direction toward and away from the driven shaft  43 . The floating shaft  44 , and thus the floating idler member  41 , is resiliently biased by a spring  46  or other suitable resilient biasing means toward the driven member  40 . 
         [0021]    In operation of the machine  15 , the stock supply assembly  30  supplies stock material to the forming assembly  31 . The forming assembly  31  causes inward rolling, shaping and crumpling of the sheet stock material to form lateral pillow portions of a continuous strip of dunnage. The feeding assembly  32  advances the stock material through the forming assembly  31  and also connects the central band to form a connected dunnage strip. As the connected dunnage strip travels downstream from the feeding assembly  32 , the severing assembly  33  severs or cuts the dunnage strip into sections, or pads, of a desired length. The severed pads then travel through the post-severing assembly  34 . 
         [0022]    The machine  15  as thus far described is generally the same as the machine described in greater detail in U.S. Pat. No. 6,387,029, and reference may be had thereto for further details of the general arrangement and operation of the machine. 
         [0023]    As the sheet stock material is drawn through the dunnage conversion machine  15 , the stock material is manipulated by the forming assembly  31  to give the stock material structure and shape as a relatively less dense strip of dunnage. As the stock material advances through the forming assembly  31 , the stock material crumples, forming chevrons, crevices, folds, and other similar vertical and angular surfaces. The size and shape of these folds, crevices, etc. generally is dependent on multiple factors, such as the type of stock material, the type of forming assembly and the speed at which the stock material is advanced through the forming assembly. The crumpled surfaces have to pass under the idler shaft  44  of the rotating member  41  in the feeding assembly  23 . As these surfaces hit the shaft  44 , some surfaces can extend above the shaft  44  and are pulled against the shaft as the stock material advances between the rotating members  40  and  41 . When the surfaces are stiff enough, the stock material can wrap around the shaft  44  and hold back or slow down the feeding of the stock material. This forces the stock material that is in engagement with the rotating member  41  to travel upward and potentially jam the rotating members  40  and  41  and prevent or inhibit further rotation, or otherwise hinder the smooth advancement of the stock material through the forming assembly  31 . 
         [0024]    The dunnage converter provided by the present invention includes further improvements to the feeding assembly that serves to minimize or prevent jamming or other problems. Except as otherwise provided, the dunnage converter provided by the present invention is the same as the prior art dunnage converter described above. 
         [0025]    As shown in  FIGS. 2 and 3 , the dunnage converter  115  provided by the present invention includes a feeding assembly  132  with a pair of opposed rotating members  140  and  141  mounted on respective opposed driven and idler shafts  143  and  144 . The idler rotating member  141  is mounted to the idler shaft  144  with a bushing  147  that allows the rotating member  141  to rotate relative to the shaft  144 . In the illustrated feeding assembly  132 , the driven and idler shafts,  143  and  144  are parallel to each other. The idler rotating member  141  is biased into engagement with the driven rotating member  140  by a pair of springs  146  acting on ends of the idler shaft  144 . The illustrated rotating members  140  and  141  are gears. The springs  146  keep the rotating members  140  and  141  engaged with each other while allowing the crumpled stock material to pass therebetween. 
         [0026]    The feeding assembly  132  further includes a pair of guide members  200 , sometimes called “shoes”, mounted to the idler shaft  144  adjacent the idler rotating member  141 . The guide members  200  provided by the present invention eliminate or minimize the problems associated with the crumpled stock material catching on the idler shaft  144 . The guide members  200  present a surface to the stock material that is larger than the idler shaft  144  and present a surface that is inclined relative to the upstream-downstream direction to gradually engage the pillow portions of the crumpled strip and guide them under the idler shaft  144 . The guide member  200  can be angled or curved, but generally extends progressively away from the shaft  144 . 
         [0027]    As shown in  FIGS. 2 ,  3 , and  4 A- 4 D, the guide members  200  employ an inclined portion that presents a larger surface than the shaft  144 , and provides a lead in to the feeding assembly  132  that is more gradual and not as abrupt as the shaft  144  alone. The illustrated guide members  200  include a curved surface that has a radius that is larger than the radius of the shaft  144 , in the nature of a larger radius portion of a tube. This larger surface will span some of the crevices, folds, etc., created in the crumpled strip better than the idler shaft  144  and inhibits or prevents the crumpled strip from jamming or otherwise interfering with the feeding operation. 
         [0028]    The illustrated guide members  200  include a clamp collar  202  and a shield that generally forms the guide surface  204 . The clamp collar  202  is essentially a nut with a circular central opening  206  approximately the size of the idler shaft  144 , a radial slot  210 , and a passage  212  that traverses the slot. A screw or bolt can be inserted into the passage  212  and across the slot  210  to pull the portions of the nut across the slot together thereby reducing the size of the central opening  206  and allowing the collar  202  to grip the shaft  144 . The collar  202  mounts to the idler shaft  144 , and a hex screw can be employed in the passage  212  so that a hex key can be used to tighten the collar onto the shaft. Alternatively, the guide member can be mounted to the frame and extend between the shafts of the rotating members. In such a case, at least a portion of the guide member adjacent the shaft  144  is resilient and thus can move toward the shaft  144  as the strip passes by. 
         [0029]    The clamp collar  202  also has a flattened surface  214  that generally is parallel to the axis of the central opening  206 . This makes the guide member  200  easier to retrofit on existing converters because it allows the collar  202  to fit within the space between the idler shaft  144  and the tunnel  216  downstream of the rotating members  140  and  141 . The tunnel  216  defines a maximum width of the strip of dunnage and defines a passage from the feeding assembly  132 . The tunnel  216  includes a pair of laterally-spaced-apart side walls that define a channel and laterally constrain the stock material in an area adjacent the feed assembly  132 . The shield  204  extends substantially the entire distance along the idler shaft  144  adjacent the rotating member  141 , and preferably at least as far as the distance between the rotating member  141  and a side wall. 
         [0030]    The shield  204  is welded or otherwise attached to the clamp collar  202  to provide an inclined surface against which the crumpled surfaces of the dunnage strip can ride as they pass under the shaft  144 . The clamp collar  202  typically is affixed to a central part of the shield  204  in a dimension parallel to the shaft, and a curved portion of the collar  202  extends below the shield  204 , but this typically does not interfere with the passage of the crumpled strip. The guide members  200  are mounted so that the shield  204  extends upstream from the idler shaft  144 . The shield  204  generally extends at least as far as, if not beyond, the radial extent of the idler rotating member  141  to ensure that the crumpled strip will be unlikely to catch on the distal end of the shield, although a shorter shield can be satisfactory for many applications. Additionally, the shields generally span most of the length of the shaft  144  that otherwise would be exposed to the crumpled strip. 
         [0031]    Additionally, although the illustrated shield  204  has a radius greater than the radius of the shaft  144 , the shield is not necessarily a circular arc segment or even curved. The shield  204  provides an inclined surface that extends progressively further from the shaft  144  and guides the upper surfaces of the crumpled strip under the idler shaft  144 , but that inclined surface is not limited to the illustrated curved surface. The means for mounting the guide member  200  also is not limited to the illustrated collar  202 , although the collar provides an excellent way to direct the strip under the idler shaft  141  as the idler shaft moves vertically when the central portion of the strip moves between the rotating members  140  and  141 . The shield  204  also can have a resilient quality, in the nature of a spring, to move as the crumpled stock material impinges on it. 
         [0032]    The guide members  200  described herein can be added to any dunnage conversion machine that has at least one rotating member and an exposed shaft adjacent the one or more rotating members. 
         [0033]    Although the invention has been shown and described with respect to a certain embodiment, equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described integers (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such integers are intended to correspond, unless otherwise indicated, to any integer which performs the specified function of the described integer (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment of the invention.