Abstract:
An apparatus and method for roll packing a variety of compressible materials including a radially collapsible mandrel for easy removal of the roll packed material without tearing or telescoping of the material. The apparatus farther includes an adjustable compression roller for setting the amount of compression in the rolled material and a roll handling device that facilitates removal of finished rolls from the apparatus. In one embodiment of the invention, a packing material dispenser supplies packing material to the in-fed compressible material as it is wound upon the mandrel.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to the packaging of compressible materials such as foam and spring assemblies used in the manufacture of mattresses and the like, and is more particularly directed to an apparatus for packaging such compressible materials into a roll.  
         BACKGROUND OF THE INVENTION  
         [0002]    Conventional packaging and transportation of compressible materials such as finished mattresses, as well as foam or spring assemblies used in the manufacture of mattress products, generally involves handling of the materials in an uncompressed state. As such, the shipping and storage of the materials requires much more space than would be required if the materials were provided in a compressed state. To improve the efficiency of shipping and storage, foam mattress cores have been packaged in a compressed state by flattening the foam and sealing it in an evacuated bag. See, for example, U.S. Pat. No. 4,711,067 to Magni. This method of packaging foam cores, however, is not useful in packaging spring assemblies. In addition, storage and transportation efficiencies of the foam could be further improved by packaging the flattened cores into a tight roll.  
           [0003]    Roll packing generally involves winding-up a desired material to form a roll and then securing the roll to prevent uncoiling of the roll during handling. In the case of compressible materials such as mattresses and foam or spring cores, it is often desired to compress the materials during the roll packing process to obtain a more dense and compact roll. Various devices have been used to achieve compression of roll packed materials. U.S. Pat. No. 3,927,504 to Forrister discloses an apparatus for rolling resilient foamed sheet material without the use of a mandrel. This machine is not useful for packaging spring assemblies and does not have the capability to package multiple units of a compressible material into a large roll. The device further does not provide for packaging a compressible material with a barrier layer between successive turns of the roll, which barrier layer is desirable to prevent adhesion between successive layers of foam.  
           [0004]    Some roll packing systems further include a mandrel for facilitating the winding of the material. For example, U.S. Pat. No. 2,114,008 to Wunderlich discloses a spring packing machine having a radially collapsible arbor for use in roll packing spring assemblies. A barrier layer between successive turns of the roll keeps the spring assemblies separate and permits easy removal of a single assembly from the roll. However, this machine is not useful for roll packing foam material due to the presence of a pressure bar  50 , between belt  15  and the collapsible arbor, which would tend to snag a compressed foam as it passed beneath. The disclosed machine also has other drawbacks. For example, to remove a finished roll, the arbor must be removed from the machine and collars must be adjusted to collapse the arbor so that the roll can be taken off the arbor. The arbor must then be replaced in the machine before another roll can be formed. Operation of the machine is thus very labor intensive and ergonomically inefficient.  
           [0005]    There is thus a need for a simple apparatus capable of roll packing multiple units of various compressible materials, such as foam mattress cores, mattress spring assemblies, and finished mattress products and which is ergonomically efficient and is capable of providing a barrier layer between successive turns of a formed roll.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention provides a simple machine for roll packing a variety of compressible materials such as foam cores, spring assemblies, and fiber materials used in the manufacture of mattress products, as well as finished mattresses themselves. The machine has a radially collapsible mandrel that permits finished roll packed materials to be easily removed from the machine by sliding the roll off of the mandrel. This radially collapsible mandrel permits rolled materials to be removed without any telescoping or tearing of the materials which is usually caused by binding of the roll packed material on the mandrel. The machine of the present invention is especially useful in roll packing foam materials which are highly susceptible to binding against a mandrel. The simplicity of design of the machine of the present invention further permits use in roll packing practically any compressible material, even materials as diverse as coiled spring assemblies for mattresses and foam cores.  
           [0007]    In accordance with the present invention, an apparatus is provided having a radially collapsible mandrel for winding compressible materials to be roll packed. A feed table is provided upstream of the mandrel to support and direct the compressible material to the mandrel. A packing material dispenser is further provided proximate the mandrel to feed packing material to the mandrel with the compressible material. A compression roller associated with the mandrel is used to compress in-fed compressible materials between the compression roller and the mandrel as the material is being wound upon the mandrel. The compression roller is adjustable to vary the spacing between the mandrel and the compression roller so that the amount of compression for the in-fed materials can be varied accordingly. In one exemplary embodiment, a pneumatic cylinder is used to adjust the position of the compression roller relative to the mandrel. The mandrel is driven at one end by a driving mechanism including, for example, a motor and a gearbox, and has a bearing plate at the opposite end. The bearing plate is movable away from the end of the mandrel so that a finished roll of material can be easily pushed off of the mandrel after it has been collapsed. In another exemplary embodiment, the apparatus includes a stripper bar associated with the mandrel to facilitate the removal of finished rolls from the mandrel, and further includes a roll handler for receiving the finished roll as it is pushed off the mandrel.  
           [0008]    In further accordance with the present invention, a method for roll packing various compressible materials includes the steps of providing a collapsible mandrel and a compression roller, directing in-fed compressible materials between the mandrel and compression roller, adjusting the spacing between the mandrel and compression roller, winding the compressible material around the mandrel, stopping the mandrel when a desired amount of in-fed material has been wound upon the mandrel, collapsing the mandrel, and removing the roll packed material from the mandrel. A method for roll packing foam materials, in particular, in accordance with the present invention is disclosed in U.S. Patent application Ser. No. ______, entitled “Method for Roll Packing Foam Cores,” filed on even date herewith, assigned to the assignee of this application, and incorporated by reference herein in its entirety.  
           [0009]    Accordingly, the invention provides a simple apparatus and method for roll packing a variety of compressible materials and which has a collapsible mandrel that facilitates the easy removal of finished rolls without tearing, telescoping, or otherwise damaging the roll packed material. These and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and description. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention.  
         [0011]    [0011]FIG. 1 is a perspective view showing a roll packing apparatus according to the principles of the present invention;  
         [0012]    [0012]FIG. 2 shows detail of the mandrel and compression roller of the apparatus of FIG. 1, where an in-fed material is being compressed between the mandrel and compression roller;  
         [0013]    [0013]FIG. 3 shows a cross-sectional view of the mandrel of the present invention, taken along line  3 - 3 , showing the collapsed state of the mandrel in solid lines and the expanded state of the mandrel in dashed lines;  
         [0014]    [0014]FIG. 4A is a partial side-view of the apparatus of FIG. 1, depicting the start of a winding operation with an expanded mandrel;  
         [0015]    [0015]FIG. 4B shows the partial side-view of the apparatus of FIG. 1, depicting a partially wound roll on the expanded mandrel;  
         [0016]    [0016]FIG. 4C shows the partial side-view of the apparatus of FIG. 1, depicting a fully wound roll and the mandrel in its collapsed state.  
     
    
     DETAILED DESCRIPTION  
       [0017]    An apparatus and method are provided for roll packing compressible materials in a simple and efficient manner without damaging the materials, and wherein the materials can be stored and shipped in a compact state. The present invention may be described and understood by a description of an exemplary apparatus.  
         [0018]    With reference to FIG. 1, there is shown an illustration of one embodiment of roll packing apparatus  10  incorporating the principles of the present invention. The apparatus  10  includes a collapsible mandrel  12  for receiving in-fed materials  14  and winding them into a roll. The mandrel  12  is fixed to a shaft  16  that is driven at a first end  18  by a driving mechanism, for example motor  20  and gearbox  22  connected to the shaft  16 . The invention further includes a compression roller  24 , which is located proximate the mandrel  12  and which is fixed to a compression roller shaft  26  that is substantially parallel to the mandrel shaft  16 . Thus, the rotational axis of mandrel  12  is substantially parallel to the rotational axis of compression roller  24 . The compression roller  24  is adjustable such as by means of an actuator  28  fixed to the roller shaft  26  whereby the spacing  30  (see FIG. 2) between the compression roller  24  and the mandrel  12  may be adjusted to vary or maintain the amount of compression on the in-fed materials  14 . A feed table  32  located upstream of the mandrel  12  and compression roller  24  directs in-fed compressible materials  14  between the mandrel  12  and compression roller  24  as the material  14  is wound upon the mandrel  12 . In one example of the present invention, not shown, the feed table  32  includes a jig plate to ensure proper alignment of the in-fed materials  14  with respect to the mandrel  12  and compression roller  24 . A disc brake  34  may be attached to the roller shaft  26  to control rotation of the compression roller  24 .  
         [0019]    The apparatus  10  further includes a packing material dispenser  36  which supplies packing material  38 , such as paper, plastic or fiber material, to a surface  40  of the in-fed compressible materials  14  as they are fed through the mandrel  12  and compression roller  24 . The packing material is then wound with the compressed in-fed material to create a barrier layer between successive turns of the rolled material. In this manner, the barrier layer protects successive layers of in-fed material such as foam and prevents adhesion of the successive layers. The packing material dispenser  36  may further include a guide roller  42 , pinch rollers  44 ,  46 , and a tension roller  48  to aid in directing packing material  38  to the in-fed compressible material  14  and also to maintain proper tension and alignment of the packing material  38 .  
         [0020]    A bearing plate  50  is located at a second end  52  of the mandrel shaft  16 , opposite the drive motor  20 , and is movable to expose an end of the mandrel  12  so that a finished roll of material  54  may be removed from the mandrel  12 . The invention further includes a roll handler  58  for facilitating easy removal of the finished rolls  54 . In the exemplary embodiment of FIG. 1, the roll handler  58  is a trough-shaped cradle that is pivotally connected to a support (not shown) and can be placed in a first position near the end of the mandrel  12  for receiving a finished roll of material  54 . A stripper bar  60  associated with the mandrel  12  aids in removing a finished roll  54  from the collapsed mandrel  12  onto the roll handler  58 . The roll handler  58  may then be placed in a second position (shown in phantom) to permit operators to subsequently remove the roll  54  from the machine  10 .  
         [0021]    As depicted more fully in FIGS. 2 and 3, the collapsible mandrel  12  may include a series of elongated plates  62  attached to the mandrel shaft  16  and positioned about the shaft  16  in an overlapping arrangement to create a substantially tubular surface  64  along the length of the shaft  16 . The plates  62  are slidably connected to the shaft  16  and may move toward or away from the shaft  16  along radially extending paths  66  to increase or decrease the diameter  67  of the tubular surface  64  formed by the overlapping plates  62 . Rods  68  connected to each plate  62  engage a cam  70  attached to the shaft  16 , whereby rotational operation of the cam  70  causes the plates  62  to move either toward or away from the shaft  16  to correspondingly collapse or expand the mandrel diameter  67 .  
         [0022]    Referring to FIGS.  4 A- 4 C, the method of the present invention, as it relates to operation of the exemplary apparatus  10  of FIGS.  1 - 3 , will be described. The spacing  30  between the mandrel  12  and compression roller  24  is adjusted to provide a desired amount of compression in the in-fed compressible material  14 . Packing material  38  from the packing material dispenser  36  is fed through the guide roller  42 , pinch rollers  44 ,  46 , and tension roller  48  and then directed between the compression roller  24  and mandrel  12  while the mandrel  12  is turned to wind an initial length of packing material  38  upon the mandrel  12 , as depicted in FIG. 4A. In-fed compressible material  14 , which is supported on feed table  32 , is directed between the mandrel  12  and compression roller  24 . The motor  20  (FIG. 1) is started and the mandrel  12  rotates to wind up the in-fed compressible material  14  and packing material  38  as it is compressed between the mandrel  12  and compression roller  24 . The actuator  28  (FIG. 1) attached to the compression roller shaft  26  may be operated to vary the spacing  30  between the mandrel  12  and compression roller  24  as the roll  54  gets bigger, as can be seen in FIG. 4B, to maintain uniform compression in the roll  54 . When a sufficient amount of compressible material  14  has been wound upon the mandrel  12 , the motor  20  is stopped. The finished roll  54  is secured, for example, with tape, straps, or other suitable material, and bearing plate  50  (FIG. 1) is moved to expose an end of the mandrel  12 . The mandrel  12  is then collapsed, as depicted in FIG. 4C, so that the finished roll  54  may be removed from the mandrel  12  under the operation of the stripper bar  60  (FIG. 1). The stripper bar  60  pushes the finished roll  54  into the roll handler  58  (FIG. 1) and the roll handler  58  then pivots to a second position so that operators can maneuver the finished roll  54  away from the machine  10 .  
         [0023]    While the present invention has been illustrated by the description of an embodiment thereof, and while the embodiment has been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of applicant&#39;s general inventive concept.