Abstract:
A spool holder for a sewing machine, which holder finds particular use in a serger-style sewing machine, nests in the core of a thread spool and is matable with a spindle to generally maintain the thread spool in a stationary position for unwinding of the thread wound on the spool during a sewing operation, which spool holder may rotate on the spindle from the application of undue forces but is stable and strong enough to provide stability to the thread spool and its core.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to a spool holder for sewing machines. More particularly, the invention relates to a honeycomb-shaped spool-holder for holding a cone-shaped thread holder on a spindle of a serger-style sewing machine. 
   A variety of thread holders have been disclosed for use with sewing machines. The thread is commonly wound around a cone-shaped or cylindrical spool or core. A spool holder is generally inserted into the base of a thread holder or core prior to mounting on a sewing machine spindle for unwinding of the thread. A common thread bobbin and mated spool holder, which are mounted on a sewing machine spindle, will typically rotate and wobble as the thread is dispensed from the spool and bobbin with the spool holder rotating at a high angular velocity. 
   Some of these thread holders and spool holders have been specifically designed for use on serger-style sewing machine with the thread commonly wound around a cone-shaped spool. A spool holder is generally inserted in the base of the cone-shaped spool prior to mounting the mated pair onto a sewing machine spindle. During operation of the sewing machine, the mated spool holder and thread holder tend to jump and wobble as the thread unravels from the cone-shaped spool. In a serger-style sewing machine, the thread is typically unwound from the spool, and it is very desirable to maintain the cone-shaped spool holder in a stationary position to allow the thread to unwind from the spool as smoothly as possible rather than to allow the thread spool to rotate. 
   Preexisting spool holders for serger-style sewing machines suffer from various disadvantages, as they are generally of a weak construction and, easily crack or break during usage. Therefore, it is highly desirable to have an improved and durable spool holder capable of withstanding a wide range of dynamic forces, which may be experienced during a sewing operation. The present invention addresses this problem by providing a honeycomb-shaped spool-holder having an inner cylindrical hub, an outer conical member, and a plurality of partition walls extending in an axial direction therebetween in such manner as to sufficiently reinforce its overall structure to resist breakage during normal operations. 
   Further, the above-noted prior art spool holders may be suitable for a particular purpose, but they have not been found to have the strength and durability of the spool-holder of the present invention, and they have not been found to have the capability to maintain the spool in a relatively stable and stationary position on the spindle of a serger-style sewing machine. 
   SUMMARY OF THE INVENTION 
   A honeycomb-shaped spool-holder of relatively simple construction minimizes manufacturing costs, provides strength and durability, and provides relative stability to the retained thread-spool core, and thus to the thread wound thereon for ease of unraveling during sewing machine operation. 
   The invention has a honeycomb-shaped spool-holder with an inner cylindrical hub, an outer conical member, and a plurality of partition walls axially extending between the cylindrical hub and outer conical member. The partition walls reinforce the spool-holder structure to resist breakage of a spool holder during normal operations of a sewing machine, which spool holder has been mated with a thread-spool core. 
   The truncated conical or cylindrical exterior configuration of the spool-holder is provided in a size and shape to frictionally engage the interior surfaces of a cone-shaped thread-spool core. 
   The present invention is a honeycomb-shaped spool-holder for use with sewing machines, and more particularly with serger-style sewing machines. The serger-style sewing machines have at least one upstanding spool support spindle, and may have a plurality of support spindles. The honeycomb-shaped spool-holder has an inner cylindrical hub with a central bore extending therethrough for vertically receiving the spindle of a sewing machine. The spool-holder may freely rotate about the spindle as the thread unravels from the spool, although the thread generally unravels with minimal or no rotational movement of either the spool-holder or spool-thread core about the spindle. The spool-holder outer member has a truncated conical configuration, which is sized and shaped to frictionally engage the interior surfaces of a cone-shaped spool-core. As noted above, a plurality of partition walls extend in an axial direction between the inner hub and the outer member such that a spoke or honeycomb pattern is formed between the hub and the outer wall. The partition walls strengthen the structure of the spool holder to withstand a wide range of dynamic forces experienced by the spool-holder and thread-holding core, which dynamic forces result from thread being unwound from the thread-holding core. In addition, strains may be experienced by the spool-holder and the affixed core from occasional and inadvertent rotation of these components about the spindle when the aforementioned dynamic forces are great enough to rotate the mated spool-holder and core. 
   To the accomplishment of the above and related objects, the invention may be embodied in the form illustrated in the accompanying drawings. The drawings are merely illustrative and not a limitation. Variations of the invention structure are contemplated as being part of the invention, limited only by the scope of the claims. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
     In the drawing, like reference numerals refer to like elements. The drawings are briefly described as follows: 
       FIG. 1  is a diagrammatic perspective view of a preferred embodiment of a honeycomb-shaped spool holder of the present invention; 
       FIG. 2  is a top plan view of the honeycomb-shaped spool-holder; 
       FIG. 3  is an exploded view of the present honeycomb-shaped spool-holder, a cone-shaped thread holder, and an upstanding spool support spindle; 
       FIG. 4  illustrates a plurality of upright spindles on a base with a thread guide tree; and 
       FIG. 5  shows an upright spool-thread core. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 and 2  illustrate a preferred embodiment of honeycomb-shaped spool holder or means for holding  10  in accordance with the teaching of the present invention. An upstanding spool support spindle  33  is illustrated in  FIG. 3 , which spindle  33  holds spool holder  10  and sewing thread spool cores  38  extending upward from base plate  30  of spindle holder  60  noted in  FIG. 5 . Base plate  30  of spindle holder  60  includes a plurality of spindles  33  and thread guide tree  28  having several thread guides  26  attached to crossarm  24 , which guides  26  receive therethrough thread  35  from thread spool  36  for use in a sewing operation. Spool holder  10  holds thread spool  36 , which has cone-shaped spool core  38  with conventional sewing threads  35  wound thereon. 
   In  FIGS. 1 and 2 , spool holder  10  has outer member  43 , which has an overall truncated conical shape configured for frictionally engaging interior surface  38   a  of cone shaped spool core  38 . Honeycomb shaped spool holder  10  has bottom end  10   b  and top end  10   t , where the diameter of top end  10   t  may be smaller than the diameter of bottom end  10   b , which creates a tapered and truncated conical exterior configuration. It is not requisite that top end  10   t  be smaller than bottom end  10   b , which would make spool holder  10  generally cylindrical. Flange  37  extends radially from bottom end  10   b  of spool holder  10  to retain thread-spool core  38  with sewing thread  35  against downward movement on spool holder  10 . 
   Spool holder  10  includes inner cylindrical hub  39  with central bore  41  extending there through for vertically receiving spindle  33  of a sewing machine. In a preferred embodiment, central bore  41  of spool holder  10  has central longitudinal axis  42  and is sized to allow holder  10  to engage or mate with spindle  33 , which restricts or inhibits rotation of spool holder  10  and cone-shaped spool core  38  as thread  35  is unraveled and dispensed from spool core  38 . Alternatively, interior surface  41   a  of hub  39 , which is shown as a cylinder, may be tapered from bottom end  10   b  to top end  10   t  to frictionally secure spool holder  10  on spindle  33 . The noted taper in central bore  41  would be wider at bottom end  10   b  and more narrow at top end  10   t  but the taper should be adequate to initially receive spindle  33  at least one-half the length between bottom end  10   b  and top end  10   t . The precise mechanism inhibiting the rotation of spool holder  10  and core  38  is not asserted, but may be due to the weight of thread spool  36 , frictional engagement between spool holder  10  and spindle  33 , the resistance between similar materials or any other mechanism. 
   A plurality of partition walls  45  extends in an axial direction between inner hub  39  and outer member  43  such that a honeycomb or spoke pattern is formed as shown in  FIG. 2 . Partition walls  45  help to sufficiently strengthen spool holder  10  to resist a wide range of dynamic forces. These dynamic forces may be applied while spool holder  10  is constrained against rotation about spindle  33 , as thread  35  is unraveled or unwound from spool core  38 . If slippage of core  38  on spool holder  10  occurs, or if the mated core  38  and spool holder  10  slip on spindle  33  during unraveling of thread  35  from core  38 , spool holder  10  is adequately strengthened to allow rotation of either spool holder  10  or core  38  thereon. Spool holder  10  may be constructed of any suitable lightweight and durable material, such as plastic, nylon, rubber, which specific requisite grade of such materials may be selected based upon their specified characteristics noted by the manufacturer. 
   Honeycomb shaped spool holder  10  is vertically mounted on a sewing machine by extending an upstanding spool support post or spindle  33  through central bore  41  of spool holder  10 . A cone-shaped thread holder  38  with thread  35  wound thereon is placed over spool holder to, which is mounted about upstanding support post  33 . Cone-shaped holder  38  with thread  35  and honeycomb-shaped spool holder  10  are mated with and retained on spindle  33  while thread is unraveled from cone-shaped core  38 . Although central bore  41  snugly engages spindle  33  in the normal operating mode, it is known that undue forces may be imposed on thread  35 , and thus cone holder  38 , during operation of sewing machine  62  and the unraveling of thread  35 . Therefore, holder  10  may slip whenever rotational forces above the usual operating mode are imposed on spool holder  10 . In addition, spool holder  10  has a very durable construction to avoid breaking or cracking during normal usage. The present structure provides strength to spool holder  10  to resist fracture when excess stresses from thread unwinding induce rotation of spool holder  10  on spindle  33 . 
   In an alternative situation, spindle  33  may have a tapered or arcuate footing  47  to contact central bore  41  at bottom end  10   b , which may provide added frictional engagement between spool holder  10  and spindle  33 . This engagement would provide further resistance to rotational movement of spool holder  10  and cone-shaped core  38 . This is not a limitation as to the operation of spool holder  10 , as the specific embodiment of the spool holder for a desired application may utilize a frictional engagement between spindle  33  and spool holder hub interior surface  41   a.    
   In addition, ridges, nodes or protuberances  49  on interior surface  41   a , as noted in  FIG. 1 , may provide a more secure or frictional contact with spindle  33 . The added contact between protuberances  49  and spindle  33  would further resist rotation of spool holder  10 . The shape of ridges, nodes or protuberances  49  in  FIG. 1  is not a limitation, but is illustrative, and these ridges may have any appropriate shape. 
   Similarly in  FIG. 1 , ridges, nodes or protuberances  51  may be provided on outer member external surface  10   e  to engage spool core inner surface  38   a  and to retain spool core  38  on holding means  10 . 
   Many specific details contained in the above description merely illustrate preferred embodiments and are not to be construed as a limitation on the scope of the invention. Many other variations are possible.