Patent Publication Number: US-2006000938-A1

Title: Wire dispenser with frictional drag

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application claims the benefit of and priority from U.S. provisional application Ser. No. 60/584,914 filed on Jul. 1, 2004. 
    
    
     BACKGROUND AND BRIEF SUMMARY  
      The present invention relates generally to wire dispensers used by electricians, for example. More particularly, the present invention provides an inexpensive and adjustable frictional drag that prevents overspinning of wire as the wire is pulled off a rotating spool.  
      The prior art includes complicated wire feeding devices for use in automatic welding machines (U.S. Pat. No. 5,810,283). Complex braking mechanisms are also known to prevent binding or overspinning (U.S. Pat. Nos. 3,819,127; 3,796,392 and 4,124,176). The prior art also includes devices for rotatably mounting a spool of wire used by electricians (U.S. Pat. Nos. 4,548,368; 5,222,683; 6,086,013 and 6,523,777). Those devices either have no frictional drag or utilize a guide slot to frictionally engage the wire strand or a transverse rod to frictionally engage the outer circumference of the wire spool hub. The frictional engagement between the strand of wire and guide slot requires expensive and cumbersome equipment and the user must thread the wire strand through the guide slot. These devices do not lend themselves to the use of wire spools having flanges or hubs of different diameters.  
      There is a need for an inexpensive, easily used wire dispenser for electricians and others having a drag mechanism which prevents overspinning, allows the user to pull two or more sizes of wire from a single dispenser, does not require the use of special spools and does not require the user to thread the wire through a guide slot.  
      The present invention satisfies that need by providing a frictional collar that is preferably adjustable and engages the side of the spool, rather than the wire strand or the circumference of the spool. Two or more spools of different sizes may be mounted on the same shaft and one or more frictional collars of the present invention will create the desired drag on multiple spools simultaneously. The frictional collar is inexpensive, easy to use and quickly installed. It may be retrofitted onto existing wire caddies.  
      A primary object is to provide a portable wire dispenser for use by electricians (and other) which prevents overspinning by creating a frictional drag on the side of the wire spool.  
      A further object is to provide a wire dispenser which carries wire spools of different sizes and with wire of different thicknesses.  
      Another object is to provide a wire dispenser capable of handling multiple wire spools with independently adjustable drag on each separate spool.  
      A further object is to provide a frictional collar than can be retrofitted onto most existing wire caddies.  
      Further objects and advantages will become apparent from the following description and drawings, wherein: 
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       FIG. 1  is a front elevational view of one embodiment of the invention;  
       FIG. 2A  is a front elevational view of the friction collar means utilizes in the embodiment shown in  FIG. 1 ;  
       FIG. 2B  is a side elevational view of the friction collar shown in  FIG. 2A ;  
       FIG. 3  is a front elevational view of an alternate embodiment of the friction collar means;  
       FIG. 4  is a front elevational view of a further embodiment of the frictional collar means;  
       FIG. 5A  is a front elevational view of a further embodiment of a frictional collar means;  
       FIG. 5B  is yet another embodiment of a frictional collar means for use with the invention;  
       FIG. 6  is a front elevational view of an alternate embodiment of the invention showing multiple and different sized wire spools in use; and  
       FIG. 7  is a schematic representation showing the independent adjustability of the frictional drag.  
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a front elevational view showing one embodiment of the invention. A spool of electrical, single conductor wire is shown as  20  and is carried by a conventional wire caddy  40 . Only a portion of wire caddy  40  is shown in  FIG. 1  for clarity. Wire caddy  40  can be of various designs known, such as shown in U.S. Pat. Nos. 4,548,368 and/or 5,222,683. A vertical frame member  41  is commonly made of steel rod and is welded to a horizontal foot  42 . Foot  42  is typically placed on the ground or floor (not shown) at a job site.  
      A horizontal spool carrying shaft  44  is welded to frame member  41  at their intersection  45 .  
      Spool  20  has first and second hubs  21  and  22  and carries a length of either single conductor or multi-conductor wire  30 . The free end  31  of wire  30  is pulled off spool  20  as needed.  
      The friction collar means  50  of the present invention includes a body  51 , a passageway  52  that slidably engages shaft  44 , and a connector means  60 . Connector means  60  as shown in  FIG. 1  is a bolt which threads through one side of body  51  and is tightened against shaft  44 .  
      As shown in  FIG. 1 , as the free end  31  of wire  30  is pulled off spool  20 , hub  21  frictionally engages frame member  41  and hub  22  frictionally engages friction collar means  50 . The strength of the drag caused by friction collar means  50  on spool  20  varies with the axial force  70  applied by the user to friction collar means  50  as connector means  60  is tightened. Alternatively, two friction collars will be utilized, one on either side of spool  20 , to avoid friction between frame  41  and spool  20 .  
       FIG. 2A  is a front elevational view of one embodiment of friction collar means  50  of  FIG. 1 . Body  51  is aluminum, and has a passageway  52  that slidably engages shaft  44 . Connector means  60  is a bolt  61  which threads into threaded passageway  62  in body  51 .  FIG. 2B  is a side elevational of the collar means  50  of  FIG. 2A .  
       FIG. 3  is a front elevational view of an alternate frictional collar means  150 . Grooves  155  and  156  are formed in the face  158  of body  151  that bears against hub  22  of spool  20  shown in  FIG. 1 . Grooves  155  and  156  increase the friction between collar  150  and spool  20 .  
       FIG. 4  illustrates another embodiment of friction collar means  250  wherein a layer of frictional material  280 , such as ceramic materials used on brake pads, for example, is carried by face  258  of body  251 .  
       FIG. 5A  illustrates a preferred embodiment of friction collar means  350  wherein a wave spring  390  is carried by face  358 . Wave spring  390  applies a constant axial force and a constant frictional drag to wire spool  20 . A layer of frictional material  380  is optionally carried by wave spring  390  as shown in  FIG. 5B .  
       FIG. 6  illustrates how the frictional collar means  50  may be used in conjunction with two or more spools of wire.  
      On one side of member  41  a friction collar  450  is attached to shaft  44  adjacent member  41 . Wire spool  420  is slid onto shaft  44  and adjacent collar  450 . Collar  550  is slid onto shaft  44 , appropriate axial pressure is applied and collar  550  is tightened. Wire spool  520  is slid onto shaft  44  and then collar  650  is slid onto shaft  44 , axial pressure applied and collar  650  is tightened onto shaft  44 . Wire on spools  420  and  520  can now be fed simultaneously if desired, and there will be no overspinning! Spools  420  and  520  each have a friction collar bearing against each hub. This feature allows the use of greater drag on spool  420  than on spool  520 , if desired. Friction collars  450 ,  550  and  650  prevent axial drifting or motion of wire spools  420  and  520 .  
      Alternately, spools  620  and  720  can be slid onto shaft  44  with spool  620  frictionally engaging member  41  and spool  720  frictionally engaging spool  620 . Collar  750  is now slid onto shaft  44 , axial pressure applied and collar  750  tightened onto shaft  44 . Spools  620  and  720  now both have frictional drag from a single collar  750 . Both spools  620  and  720  will turn when wire is pulled off either spool. If the user only wants wire from spool  620 , and no wire from spool  720 , he simply takes the free end of the wire from spool  720  and attaches it to one of the hubs of spool  720 . Spool  720  will rotate with spool  620 , but no wire will come off spool  720 .  
      Connectors other than standard bolts may be utilized for connector means  60 , for example, Allen screws or thumbscrews.  
       FIG. 7  illustrates how friction collars  850 ,  950  and  1050  create independently adjustable frictional drag on wire spools  820  and  920 . Spools  820  and  920  are “interleaved” between collars  850 ,  950  and  1050 . The term “interleaving,” as used herein and in the claims, means an alternating array of friction collars and spools so that no two adjacent spools frictionally engage each other and that a friction collar is placed at each end of a plurality of spools. Each of frictional collars  850 ,  950  and  1050  uses the wavespring design shown in  FIG. 5A . The user first loads collar  850  onto shaft  44  and tightens connector means  860  securely to shaft  44 . Spool  820  and collar  950  are then slid onto shaft  44 . The user then applies an axial force F 1  to collar  950  as connector means  960  is tightened. Force F 1  is transmitted by wavesprings  890  and  990  to hubs  821  and  822 . Spool  920  and collar  1050  are then slid onto shaft  44 . A different, larger axial force F 2  is applied to hub  922  by pressing collar  1050  in the direction toward the center of spool  920  as shown by arrows F 2  Connector means  1060  is tightened securely to shaft  44  as axial force F 2  is applied. The result is that the larger spool  920  has a larger frictional drag F 2  applied to it than the drag F 1  applied to spool  820 . The amount of drag applied to each spool ( 820  and  920 ) is independent and independently adjustable. Pulling wire off spool  920  will not cause spool  820  to spin. Spools  820  and  920  are held in place axially on shaft  44  and cannot drift or slide on shaft  44 . Spools  820  and  920  may be of different sizes and carry wire of different thicknesses. More than two spools of wire can be loaded on shaft  44 .  
      As noted above, the friction collars described herein can be retrofitted onto existing wire caddies. Furthermore, each friction collar may carry one or two wavesprings.  
      The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teaching. The embodiments were chosen and described to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best use the invention in various embodiments and with various modifications suited to the particular use contemplated. The scope of the invention is to be defined by the following claims.