Abstract:
A compact dunnage conversion machine includes a converging chute with a restricted inlet, a powered feed assembly with a sealed gearbox, a plurality of interchangeable power supplies, and a restricted outlet chute. The converter can convert a sheet stock material into dunnage for use in packaging one or more objects in a container. The restricted inlet and outlet make it more difficult for foreign objects to enter the converter and disrupt the conversion process. The sealed gearbox interposed between the driving elements of the feed assembly and an electric motor facilitates maintenance and repair of the feed assembly, while also protecting the gears therein. Finally, the power supplies provide electrical power to the motor and can include an electrical storage device, such as a battery, or an alternating-current-to-direct-current converter which is connectable to a source of electricity for supplying that electricity to the motor in an acceptable form.

Description:
[0001]    This application is a divisional of U.S. patent application Ser. No. 11/761,099, filed Jun. 11, 2007, which claims the benefit of U.S. Provisional Patent Application No. 60/804,431, filed Jun. 10, 2006, both of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to a dunnage converter for converting a sheet stock material into a dunnage product, and various improvements thereof. 
       BACKGROUND 
       [0003]    Dunnage conversion machines, also referred to as converters, generally convert a sheet stock material into a strip of dunnage. The dunnage is then placed in a container with one or more objects for shipment. 
         [0004]    Some converters produce a dunnage product primarily to provide cushioning in a packaging container to prevent or minimize damage to the contents during shipment. U.S. Pat. No. 5,674,172, for example, which is hereby incorporated herein by reference, discloses a cushioning conversion machine for converting a sheet stock material into a cushioning dunnage product. The cushioning conversion machine includes a forming assembly that causes inward rolling of the lateral edges of the sheet stock material to form a strip having a three-dimensional shape with lateral pillow-like portions separated by a thin central band. The forming assembly includes a shaping member over which the sheet stock material is drawn and a converging chute cooperative with the shaping member to roll the edges of the stock material inward to form the lateral pillow-like portions. A feed mechanism downstream of the forming assembly pulls the stock material through the forming assembly. The feed mechanism also connects overlapping layers of stock material along the thin central band. The feed mechanism has a pair of rotating gear-like members that engage and pull the stock material over the shaping member, through the converging chute, and connect, by coining, the overlapping layers in the thin central band to maintain the three-dimensional shape of the strip. The conversion machine further includes a cutting mechanism for cutting the strip into cut sections, or pads, of a desired length for use as a protective cushioning dunnage product. 
         [0005]    Other converters produce a dunnage product primarily to fill voids in a packaging container to prevent or minimize shifting of the contents during shipment. These machines typically operate at relatively high speeds. An exemplary dunnage converter is disclosed in International Patent Application No. PCT/US2001/018678, published under Publication No. WO 01/094107 on Dec. 13, 2001, and International Patent Application No. PCT/US2003/012301, filed on Apr. 22, 2003, and published under Publication No. WO 03/089163 on Oct. 30, 2003, both of which are hereby incorporated herein by reference. 
         [0006]    An exemplary machine of this type includes a forming assembly for shaping a sheet stock material into a continuous strip of dunnage and a pulling assembly for advancing the sheet material through the forming assembly. The forming assembly includes a funnel portion, similar to a converging chute, through which the sheet stock material passes for shaping the sheet stock material into the strip of dunnage and directing the formed strip to the pulling assembly. The pulling assembly includes at least two opposed grippers, at least one of which is moveable through a dunnage transfer region in opposition to the other gripper. The grippers are cooperative to define an aperture therebetween and to grip the sheet stock material therein and advance it through the transfer region. The moving gripper includes a plurality of paddles that aid in defining the aperture and in engaging the sheet stock material. The grippers can help to crease the crumpled folds in the strip to help it maintain its shape. Due to the aperture between the grippers, however, the grippers generally cannot coin or stitch together the layers of stock material passing therebetween, in contrast to the gear-like members in the aforementioned cushioning conversion machine. 
       SUMMARY 
       [0007]    A compact dunnage conversion machine includes a converging chute with a restricted inlet, a powered feed assembly with a sealed gearbox, a plurality of interchangeable power supplies, and a restricted outlet chute. The converter can convert a sheet stock material into dunnage for use in packaging one or more objects in a container. The restricted inlet and outlet make it more difficult for foreign objects to enter the converter and disrupt the conversion process. The sealed gearbox interposed between the driving elements of the feed assembly and an electric motor facilitates maintenance and repair of the feed assembly, while also protecting the gears therein. Finally, the power supplies provide electrical power to the motor and can include an electrical storage device, such as a battery, or an alternating-current-to-direct-current converter which is connectable to a source of electricity for supplying that electricity to the motor in an acceptable form. 
         [0008]    Accordingly, a dunnage converter for converting a stock material into a relatively less dense dunnage product comprises a powered feed assembly and at least two power supplies. The feed assembly has at least one rotatable member for engaging and feeding stock material, and an electric direct current motor for driving the at least one rotatable member. The power supplies are interchangeably connectable to the motor. A first power supply has a battery, and a second power supply is connectable to a source of alternating current and has an alternating-current-to-direct-current converter for supplying direct current to the motor. In a packaging system, the converter may be mounted on a stand, which also may support a power supply and/or a supply of sheet stock material. 
         [0009]    Another dunnage converter for converting a sheet stock material into a relatively less dense dunnage product comprises a powered feed assembly for feeding the stock material that has at least one rotatable member, a motor for driving the at least one rotatable member and a gear box interposed between the at least one rotatable member and the motor for transferring rotational motion from the motor to the at least one rotatable member. The gear box includes a housing that encloses at least one gear, and the housing has a first opening therein for receipt of a shaft of the motor and a second opening for receipt of a shaft for each rotatable member. The motor shaft may pass through one side of the housing and the shaft for the rotatable member may pass through an opposing side of the housing. The motor may be mounted to the gear box housing. 
         [0010]    Still another dunnage converter for converting a sheet stock material into a relatively less dense dunnage product, comprises a converging chute having a first pair of opposed side walls that generally converge towards each other in a downstream direction and a second pair of opposed top and bottom walls that interconnect the side walls. The top and bottom walls define a constriction adjacent an upstream end of the chute where the top and bottom walls gradually converge toward each other to define a minimum distance therebetween of no more than about 30 mm. 
         [0011]    Another dunnage converter for converting a stock material into a relatively less dense dunnage product comprises a powered feed assembly for feeding a stock material and an output chute downstream of the feed assembly that guides the stock material to an outlet opening thereof that is spaced from the feed assembly. The output chute has a pair of opposed walls that have a minimum distance therebetween of no more than about 32 mm adjacent the outlet opening. The output chute may have a length of about 150 mm to about 200 mm. 
         [0012]    The foregoing and other features of the invention are hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail one or more illustrative embodiments of the invention. These embodiments, however, are but a few of the various ways in which the principles of the invention can be employed. Other objects, advantages and features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective view of an exemplary dunnage conversion machine provided in accordance with the present invention, looking from above and toward an upstream end of the conversion machine. 
           [0014]      FIG. 2  is a perspective view of a stand for supporting the conversion machine and a supply of sheet stock material at an elevated position. 
           [0015]      FIG. 3  is a side view of the conversion machine of  FIG. 1 . 
           [0016]      FIG. 4  is a top view of the conversion machine of  FIG. 1 . 
           [0017]      FIG. 5  is a bottom view of the conversion machine of  FIG. 1 . 
           [0018]      FIG. 6  is a front view of the conversion machine of  FIG. 1 , looking from the downstream end toward the upstream end of the conversion machine. 
           [0019]      FIG. 7  is a rear view of the conversion machine of  FIG. 1 , looking from the upstream end toward the downstream end of the conversion machine. 
           [0020]      FIG. 8  is a perspective view of the conversion machine of  FIG. 1 , as seen from below and looking toward the upstream end of the conversion machine. 
           [0021]      FIG. 9  is an exploded view of the conversion machine shown in  FIG. 1 . 
           [0022]      FIG. 10  is a schematic diagram of a powered portion of a conversion machine provided in accordance with the present invention. 
           [0023]      FIG. 11  is a perspective view of a power supply for the converter shown in  FIG. 1 , with a battery. 
           [0024]      FIG. 12  is a perspective view of a power supply for the converter shown in  FIG. 1 , with an AC-to-DC converter. 
           [0025]      FIG. 13  is a perspective view of an exemplary strip of dunnage. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    Referring now in detail to the drawings, and initially  FIGS. 1-9 ,  FIG. 1  shows an exemplary compact dunnage conversion machine (i.e., converter)  20  for converting a sheet stock material  22  ( FIG. 3 ) into a strip  24  ( FIG. 13 ) of dunnage. The converter  20  is part of a packaging system  26  that also includes an adjustable stand  40 , shown in  FIG. 2 , on which the converter  20  is mountable at an elevated location. 
         [0027]    The stand  40  shown in  FIG. 2  includes a base  42  and a telescopically adjustable upright  44  to which the converter  20  can be secured. The base  42  includes wheels  46  so that the stand  40  may be moved easily. The base  42  of the stand  40  can have a different configuration, however, such as a clamp for mounting on a table. 
         [0028]    Referring now to  FIG. 9  as well, the converter  20  is mountable to the stand  40  via a pair of rotating guide plates  50  pivotally rotatable through a pivot shaft  52  passing therethrough to the arms of a generally U-shape bracket  54 , the base of which can be secured to the stand at “A” in  FIGS. 1 and 2 . The stand  40  and the converter mounting bracket  54  cooperate to allow a packer to orient the converter  20  so that the converter  20  discharges dunnage products exactly where the packer wants them. Specifically, the stand  40  and the converter mounting bracket  54  operate to allow the packer both to rotate the converter  30  about a substantially vertical axis and to pivot the converter  20  about a substantially horizontal axis. The illustrated stand  40  also allows the packer to raise and lower the height of the converter  20 . This adjustability provides several advantages. Rotating the converter  20 , for example, allows multiple packers, spaced around the vertical rotation axis of the stand  40  at separate packing stations, to use the same converter  20 . That is, the converter  20  can be swung back and forth between the two packing stations as needed. Pivoting the converter  20  about a horizontal axis allows the packer to change the angle at which the dunnage exits the converter  20  relative to the stand  40  or a packing surface (not shown). In addition, adjusting the height of the stand may be desirable to accommodate different ranges of box sizes, or packers of different heights, for example. 
         [0029]    The stand  40  also includes a support, such as the illustrated tray  60  mounted to the upright, for supporting a supply  62  of sheet stock material  22 , such as that shown in  FIG. 3 . The supply  62  supplies the converter  20  with one or more plies of sheet stock material, which typically consists of paper, particularly kraft paper, and typically about fifteen inch (about thirty-eight centimeters) wide to about thirty inch (about seventy-six centimeters) wide kraft paper. A common width in twenty-two and a half inches (about fifty-seven centimeters). A paper dunnage product is an environmentally responsible protective packaging material; paper is recyclable, reusable and composed of a renewable resource. Other sheet materials may be suitable alternatives to paper, however. 
         [0030]    The stock material preferably is perforated or otherwise weakened in regions that extend across its width and are spaced apart along the length of the stock material. The stock material typically is supplied as a continuous fan-folded stack that is perforated at the folds. These weakened regions make it easier to separate dunnage products from the strip of dunnage, for example by tearing, so that a desired length of dunnage can be torn from the strip as it emerges from the converter. 
         [0031]    The converter  20  includes a housing  70  that encloses a conversion assembly  72  for converting the stock material into a dunnage product. The conversion assembly  72  includes a converging chute  74  and a powered feed assembly  76  downstream of the converging chute  74 . The sheet stock material  22  is fed into an upstream end  80  of the converter housing  70  and the feed assembly  76  pulls the stock material from the supply (not shown) and through the converging chute  74 . The converging chute  74  inwardly gathers and crumples the stock material into the shape of a crumpled strip or rope  24  ( FIG. 13 ) having a generally round cross-sectional shape, typically with one or more longitudinally-extending crumpled lobes. The converted stock material exits the housing  70  at a downstream end  82  of the converter  20  as the completed dunnage strip. The terms “upstream” and “downstream” are used herein to refer to the flow of the stock material through the converter  20 , from the upstream end  80  of the converter to the downstream end  82 . 
         [0032]    In the illustrated embodiment, the housing  70  has a relatively planar bottom portion  90  that forms the bottom wall and a top portion  92  having a generally U-shape cross-section that forms the side and top walls. The bottom portion  90  in the illustrated embodiment has a hollow shape that is about seventeen millimeters thick with one or more stiffening brackets  94  mounted thereto to provide additional support and to increase the rigidity of the converter housing  70 . The top portion  92  of the converter housing  70  includes an upstream section  96  that provides the top of the converging chute  74 , and a downstream section  98  that covers the feed assembly  76 . The downstream section  98  also helps to form an outlet chute  100  downstream of the feed assembly  76  that terminates at an outlet opening  102 . The illustrated housing  70 , with its two readily removable upper sections  96  and  98 , simplifies maintenance and operation of the converter  20 . The housing  70  and components of the conversion assembly  72  therein generally define the path of the stock material through the converter  20  in a substantially upstream to downstream direction. 
         [0033]    One of those components of the conversion assembly  72  that defines the path of the stock material through the converter  20  is the converging chute  74 , best seen in  FIGS. 4 and 7 . The converging chute  74  has a first pair of opposed side walls  110  that generally converge towards each other in a downstream direction and second pair of opposed top and bottom walls  112  and  114  that interconnect the side walls  110 . The converging walls  110  of the chute  74  define a progressively smaller cross-sectional area in the downstream direction whereby the stock material is turned in on itself and crumpled to form a strip of dunnage. 
         [0034]    The top and bottom walls  112  and  114  also define a constriction  120  adjacent an upstream end of the chute  74  where the top and bottom walls  112  and  114  gradually converge towards each other to define a minimum distance therebetween of no more than about thirty millimeters. 
         [0035]    In the illustrated embodiment, the top wall  112  includes an upper protrusion  122  that gradually curves to form a hemi-cylindrical shape. The protrusion  122  extends across the path of the stock material in the upstream-to-downstream direction. Other curved shapes also may be suitable. The bottom wall  114  also includes a corresponding cylindrical lower protrusion  124  generally aligned with the upper protrusion  122  to define the constriction  120 . The longitudinal axis of either or both protrusions  122  and  124  may be straight or curved. The lower protrusion  124  also defines the lower upstream edge of the converter  20 , and also presents a gradually curving surface to guide the stock material into the converging chute  74 . The lower protrusion  124 , which in the illustrated embodiment is bowed in the middle in an upstream direction, generally provides a relatively constant entry point for the stock material entering the converging chute  74 . 
         [0036]    The constriction  120  at the upstream end of the converging chute  74  limits the ability for foreign objects to enter the converging chute  74  that could interfere with the conversion process. The constriction  120  generally has a width that is about as wide as the stock material expected to be used with the converter  20 . In an exemplary converter  20 , the side walls  110  typically are spaced apart about eighty centimeters at the constriction  120 . 
         [0037]    The powered feed assembly  76  is similar to that disclosed in U.S. patent application Ser. No. 10/887,220, filed Jul. 8, 2004, and published under Publication No. 2005-0181924 on Aug. 18, 2005, which is hereby incorporated herein by reference. The feed assembly  76  has at least one rotatable member  130 , and in the illustrated embodiment it includes a pair of rotatable members  130 , for engaging and feeding stock material from a supply thereof through the converging chute  74  in a downstream direction. The rotatable members  130  further crumple the stock material and help to fix the crumpled stock material in its crumpled state. 
         [0038]    The opposing rotatable members each have a plurality of paddles  132  uniformly circumferentially spaced apart. Each paddle  132  has a somewhat V-shape or outwardly opening cavity or indentation in the side thereof such that rotation of the rotatable members  130  causes the paddles  132  to sweep through a generally hourglass-shape volume. The opposing sets of paddles  132  together form a through-gap or channel  136  that gradually narrows as the paddles  132  progressively move toward each other as the rotatable members  130  rotate. The hourglass-shape volumes of the opposing rotatable members  130  can overlap one another as alternating paddles  132  move through the overlapping regions. In other words, the opposing paddles  132  sequentially move transversely toward or “close in” on each other as the rotatable members rotate to grip the stock material therebetween. 
         [0039]    Once the opposing paddles  132  engage the strip of dunnage, they maintain a grip on the strip for the duration of their travel along the path of the stock material through the feed assembly  76 . At the downstream end of the feed assembly  76 , the opposing sets of paddles  132  gradually diverge away from each other to release the strip of dunnage. 
         [0040]    The converter  20  also includes one or more guide members  140  that direct the gathered strip from the converging chute  74  and through the feed assembly  76  without significantly impairing the operation of the feed assembly  76  or the crumpling of the strip as it is fed therethrough. The guide members  140  extend from a position upstream of the feed assembly  76 , through the gap  136  between the opposing rotatable members  130 , to a position downstream of the feed assembly  76  to guide the stock material past the rotatable members  130 . The guide members  140  typically are secured at an upstream end, such as to a portion of the housing  70  that defines the converging chute  74 , and are free at a downstream end. Each guide member  140  generally has sufficient flexibility to move out of the way as the strip passes thereby, substantially between the guide members  140 . The guide members  140  can be formed of nylon, such as nylon cable ties, also referred to as tie-wraps. 
         [0041]    The feed assembly  76  feeds the stock material downstream and through the output chute  100  which guides the stock material to the outlet opening  102  thereof that is spaced from the feed assembly  76 , and thus out of the converter  20 . The output chute  100  provides a continuous path from the feed assembly  76  to the outlet opening  102 . The output chute  100  has a pair of opposed walls  144  that have a minimum distance therebetween of no more than about thirty-two millimeters adjacent the outlet opening  102 . The output chute  100  generally provides a rectangular passage for the stock material although it may have other shapes, including a trapezoid, for example, with a width near the top of the outlet opening  102  of about twenty-five millimeters and a width near the bottom of the outlet opening  102  of about thirty-two millimeters, and a height of about eighty-seven millimeters. The output chute  100  has a length of about one hundred fifty millimeters to about two hundred millimeters from the feed assembly  76  to the outlet opening  102 . The narrow width of the output chute  100  restricts or limits or prevents entry into the output chute  100  by foreign objects that could interfere with the conversion process, as well as guiding the stock material and perhaps contributing to its formation into a strip of dunnage. 
         [0042]    The feed assembly  76  is powered by a motor  150 . In an exemplary embodiment, the rotatable members  130  of the feed assembly  76  are driven by a rotary electric motor  150 , and at least one gear, and typically at least two gears in a gear train, for transferring rotational motion from the motor  150  to the rotatable members  130 . The rotatable members  130  can be keyed or otherwise secured to respective shafts  152  for rotation therewith. The axes of the rotatable members  130  generally extend in a direction that is parallel to an axis of the shaft  154  of the motor  150 . In the illustrated embodiment, the gear train includes a pinion gear  156  secured to the shaft of the motor  150  and a spur gear  156  and  158  secured to each shaft  152  of the rotatable members  130 . The gears  156  and  158  thus transfer the rotational motion from the shaft of the motor  150  to the shafts  152  of the rotatable members  130 . 
         [0043]    A gear box  160  is interposed between the rotatable members  130  and the motor  150 . The gear box  160  includes a housing  162 , which includes a generally tubular portion  164  that has a generally rectangular cross-sectional shape and a pair of end covers  166  that close and seal the open ends of the tubular portion  164  and thereby enclosing at least one gear within the gear box  160 . The gear box housing  162  has a first opening  170  therein through one side of the housing  162  for receipt of the shaft of the motor  150 , and a pair of second openings  172  in another side of the housing  162 , the opposing side, for example, for receipt of the shafts  152  of the rotatable members  130 . The shafts  152  of the rotatable members  130  are mounted in the gear box housing  162  with bushings  176  in aligned openings in opposing sides of the gear box  160  and extend through the converter housing  70  to the rotatable members  130  enclosed therein on an opposite side of the bottom portion  90  of the converter housing  70 . 
         [0044]    The gear box housing  160  is mounted to the housing  70  of the converter and the motor  150  is mounted to the opposing side of the gear box  160  with the shaft  154  of the motor  150  entering the gear box housing  162  from an opposite side of the gear box housing  162  from the openings  172  through which the shafts  152  of the rotatable members  130  extend. 
         [0045]    The motor  150  is typically a direct current (DC) motor. An exemplary DC motor is a twenty-four volt DC motor, such as one which can rotate its shaft at about 2,300 revolutions per minute, and provides approximately one hundred to one hundred and fifty watts of power. The power cord for the motor includes a quick disconnect connection for connection to a power supply. 
         [0046]    Turning to  FIGS. 10-12 , the dunnage converter  20  also includes at least two power supplies  200  and  202  interchangeably connectable to the motor  150 , and thus the powered feed assembly  76 , to supply electrical power thereto. A controller  203  may be provided separately from the power supplies  200  and  202 , or a controller may be incorporated in each power supply  200  and  202  to provide the necessary control functions. In an exemplary converter  20 , each power supply  200  and  202  has a housing  204  that has the same dimensions as the other power supply or supplies. Consequently, the housing  204  for each power supply typically is substantially identical such that the power supplies  200  and  202  are readily swappable, one for another. Each power supply  200  and  202  can include an indicator light  206  to provide a visual output to indicate that the power supply  200  or  202  is operational, an emergency stop button  208  that can disconnect the power supply  200  or  202  in an emergency, and one or more fuses  210  that are accessible from outside the housing  204 . A first power supply  200  has a battery  212  and a second power supply  202  is connectable to a source of alternating current (AC) and has an AC-to-DC converter  214  for supplying the direct current to the motor  150 . 
         [0047]    An exemplary power supply provides a 24 volt DC output with a current of no more than about six and a half amperes and provides approximately one hundred to one hundred fifty watts of power to the motor  150 . The AC power supply  202  can be provided in 110 volt or 220 volt alternating current versions for converting that voltage into a direct current for provision to the motor  150 . The AC power supply  202  includes a power cord  215  for connection to an outlet or other supply of alternating current, and the battery power supply  200  includes a connection  217  for a battery charger  216 . A connection  219  is provided for connecting the power supply to the motor, and this connection also may provide a connection for recharging the battery. 
         [0048]    In the illustrated embodiment, the stand  48  shown in  FIG. 2  also includes a bracket  220  for mounting the power supply  200  or  202  to the upright  44 . The power supply mounting bracket  220  has a pair of key slots  222  for receipt of a corresponding pair of screws (not shown) protruding from a back side of the power supply housing  204 . Other mechanisms for mounting the power supply  200  or  202  and connecting the power supply  200  or  202  to the motor  150  are possible. 
         [0049]    An input device, such as one or more foot pedals  230 , is connectable to the power supply  200  and  202  to control the supply of power from the power supply  200  or  202  to the motor  150 . For example, to produce dunnage a packer may press on the foot pedal until a desired length of dunnage is produced, and then release the foot pedal  230  to stop the converter. The packer can then tear the dunnage along a line of perforations at or downstream of the feed assembly  76 . Alternatively, the packer can press the foot pedal  230  once to start the motor  150 , and then press the foot pedal a second time to stop it. Other means for signaling the converter  20  and the feed assembly  76  to start and stop also may be employed. 
         [0050]    Each power supply  200  and  202  also may include multiple connections for multiple foot pedals or other type of switch so that the converter can be used by multiple packers at various stations around the dunnage converter  20 . For example, the converter  20  may be shared by two different packers at stations approximately ninety degrees apart from each other and the converter  20  may be rotated about the axis of the stand  40  for pointing the outlet opening  102  at the respective packer whereby the packer can use the nearest foot pedal  230  to control the supply of power and thus the conversion of stock material into a dunnage product. 
         [0051]    Although the invention has been shown and described with respect to certain exemplary embodiments, it is obvious that 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 components, the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiments of the invention. In addition, while a particular feature of the invention can have been disclosed with respect to only one of the several embodiments, such feature can be combined with one or more other features of the other embodiments as may be desired and advantageous for any given or particular application.