Abstract:
A sheet of flexible and resilient polymer material is rolled into a tubular configuration and inserted into the shaft of a boot deeply enough to reach the vamp and quarters from which the shaft uses. The rolled sheet, when released, expands under the bias of its own resiliency and bears against the inside of the shaft, thus stabilizing the shaft in an upright position above the quarters and vamp. The upper end of the rolled sheet projects above the upper margin on the shaft, and here the sheet may bear a trademark or other indicia.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates in general to footwear and more particularly to shape retainer and method for stabilizing the shaft of a boot. 
     The footwear industry offers a variety of stylish boots which women find particularly appealing during the winter months and in inclement weather. The typical boot has a vamp and quarters that are attached to a sole which leads back to an elevated heel. The vamp surrounds the wearer&#39;s foot and merges into a shaft which extends upwardly past the wearer&#39;s ankle along the wearer&#39;s calf. Usually the shaft has a zipper which extends from its upper margin downwardly to the sole to enable the wearer to insert her foot through the shaft and into the vamp. 
     The vamp, while being flexible, is small enough and has enough rigidity to maintain its shape when the boot is not worn. The same holds true with regard to the quarters. But the shaft does not. It usually folds over immediately above the quarters. This makes boots difficult to display in shoe stores and shoe departments of department stores. Moreover, it leaves the boots with creases which in time may develop into cracks in the leather. Apart from that, a fold in the shaft of a boot restricts the circulation of air through the interior of the vamp, and thus inhibits evaporation of moisture from within the vamp. 
     To be sure, foam stuffers exist for insertion into the shafts of boots, but they are difficult to install and often do not provide enough rigidity to maintain the shaft upright. Mechanical boot shapers with sides that are urged apart by springs also exist, but they are even more difficult to insert, and furthermore do not reach down into the quarters where the greatest support is required. Then there are cardboard expanders which are bent into a somewhat bowed configuration and fitted into the shafts to hold the shafts open in shoe boxes, but they are not suitable for displays. 
     SUMMARY OF THE INVENTION 
     The present invention resides in a boot having a shaft which extends upwardly from the vamp and quarters of the boot and is stabilized in an upright position with a sheet of flexible and resilient polymer material that is in at least a bowed condition and expanded against the inside surface of the shaft. The invention also resides in the method of stabilizing a boot shaft with a bowed sheet of resilient polymer material. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a boot having the shape retainer, constructed in accordance with and embodying the present invention, in the shaft of the boot to stabilized the shaft; 
     FIG. 2 is a perspective view of the polymer sheet that forms the shape retainer, when the sheet is open, yet slightly bowed; 
     FIG. 3 is a plan view of the polymer sheet; 
     FIG. 4 is a perspective view of the boot with the rolled polymer sheet aligned with the boot shaft for insertion into the shaft where the sheet forms the shape retainer; and 
     FIG. 5 is a sectional view taken along line  5 — 5  of FIG.  1 . 
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF INVENTION 
     Referring now to the drawings, a shape retainer A (FIG. 1) fits into a boot B where it serves to maintain the boot B generally in the shape it would have if worn. As such, the shape retainer A enables a new boot B to be displayed attractively in retail shoe stores and departments. It further enables a boot B, when not worn by the purchaser, to be stored neatly in a condition that fosters the circulation of air through the interior of the boot B. The shape retainer A also minimizes the development of creases which, apart from being unsightly, may develop into cracks in the leather. The shape-retainer fits boots B of a variety of sizes and styles. 
     The boot B has (FIGS. 1 &amp; 4) a sole  2  including a shank  4  and a heel seat  6  to which an elevated heel  8  is attached. In addition, the boot B has an upper  10  which is formed usually from leather or some other flexible material, perhaps of a synthetic composition. In any event, the upper  10  includes vamp  12  which is attached at the foreportion of the sole  2  and is configured to extend over the user&#39;s foot ahead of the ankle. In addition, the upper  10  has two quarters  14  into which the vamp  12  merges and they lie along the sides and back of the user&#39;s foot generally above the user&#39;s heel and below the user&#39;s ankle. Finally, the upper  10  includes a shaft  16  into which the vamp  12  and two quarters  14  merge. Indeed, the shaft  16  extends upwardly from the vamp  12  and quarters  14  at the region of the user&#39;s ankle and completely covers the user&#39;s ankle as well as at least the lower portion of the user&#39;s calf. The shaft  16  terminates at an upper margin  18  and contains a zipper  20  which extends downwardly from the upper margin  18  through the quarter  14  at the inside of the user&#39;s foot and terminates near the shank  4  of the sole  2 . 
     While the vamp  12  and quarters  14  will flex, particularly in the regions above the shank  4  of the sole  2 , the vamp  12  in its toe region and the quarters  14  in the heel region contain a stiffening material. This material imparts a measure of rigidity to the vamp  12  and quarters  14  and enables them to retain their shape in the absence of the user&#39;s foot. The shaft  16  is considerably more flexible and exhibits an inclination to fold, primarily in the region where it merges into the vamp  12  and quarters  14 . Of course, a folded shaft  16  appears unsightly in a display and furthermore establishes creases at the fold. Moreover, even if the shaft  16  remains upright, it usually does not present a uniform exterior surface, but instead, one marked by a depression or two, and this also detracts from the appearance of the display. The shaft  16  of a boot B that has seen use should remain upright for the further reason of allowing air to circulate through the interior of the vamp and thereby evaporate moisture. The shape retainer A occupies the entirety of the shaft  16  and further extends through the quarters  14  to the heel seat  6 . It not only maintains the shaft  16  upright, but further gives the shaft  16  a uniform exterior appearance devoid of depressions or creases and prevents creases from developing in it. 
     The shape retainer A basically comprises a sheet  30  of polymer resin that is flexible, but not to the extent that it can be folded and creased or take on a permanent set other than a slight bow. When flexed and released, it should revert to generally its original shape. Even so, when unrestrained, the sheet  30  may possess a slight bow that facilitates rolling it into a coil or tube (FIG.  2 ). It should be translucent or opaque. Suitable polymers include polycarbonate or polyvinyl chloride having a thickness ranging between 0.015 to 0.020 inches and preferably 0.015 inches. 
     The sheet  30  when fully open (FIG. 3) has a straight lower edge  32  and an arcuate upper edge  34  which curves away from the bottom edge  32 . It also has side edges  36  connecting the lower and upper edges  30  and  32 . For the most part, the side edges  36  are straight, but near their lower ends they curve inwardly toward and intersect the straight lower edge  32 . The two side edges  36  are equal in length and converge slightly toward the lower margin  32 . 
     The sheet  30  is symmetrical about a centerline X (FIGS. 2 &amp; 3) which bisects the lower edge  32  and the upper edge  36 . Its side edges  36  converge toward the lower edge  32 , lying at an angle of between 3° and 7° with respect to the centerline X and preferably at an angle of about 5°. 
     The width of the sheet  30  at the upper ends of the side edges  36 , that is the distance between the side edges  36  where they intersect the upper edge  34 , should be between 5% and 10% greater than the circumference of the shaft  16  on the boot B at the upper margin  18  on the shaft  16 . The width of the sheet  30  immediately above the inwardly curved regions of the side edges  36 , that is the distance between the lower levels of the straight portions of the side edges  36 , should be between 5% and 10% greater than the circumference of the shaft  16  where the vamp  12  and quarters  16  merge into the shaft B. The arcuate upper margin  34  at its intersection with the centerline X rises between 1½ and 3 inches above the upper ends of the side margins  36  and preferably about 2 inches. The height of the sheet  30  at its side margins  36  is about equal to the distance between the heel seat  6  at the bottom of the two quarters  14  and the upper margin  18  at the upper end of the shaft  16 . 
     Typically, the sheet  30  is about 13.6″ wide at the upper ends of its side edges  36  and is about 11.6 inches wide where the side edges  36  begin to curve inwardly. The lower edge  32  between the curved corners, that is the straight portion of the lower edge  32 , is about 7.8 inches wide. The height along the center line X is about 15.25 inches, but can range between 12.25 and 16.25 inches. 
     In its lower region the sheet  30  may have graduations  38  (FIGS. 2 &amp; 3) at equal intervals, each parallel to the lower edge  32 , to provide guidance in reducing the height of the sheet  30  so as to better accommodate shorter boots B. Along is its exposed upper region, indicia such as an advertising message or trademark  40 , may be applied to the sheet  30 . The region between the graduations  38  and the trademark  40  may contain instructions for using the shape-retainer A or other information. 
     To install the shape retainer A in the boot B, the slightly bowed sheet  30  is converted into a tubular configuration having a width less than the smallest interior dimension of the shaft  16  (FIG.  4 ). To this end, following the curvature of the slightly bowed sheet  30 , one of its side edges  36  is brought over and against one face of the sheet  30  generally in the region of its centerline X, giving the portion leading up to that side edge  36  a much more pronounced curvature. Then, the remaining portion of the sheet  30 , that is the portion leading up to the other side edge  36 , is wrapped around the previously curved portion. The other side edge  36  lies along the other face of the sheet  30 . This converts the sheet  30  into a tubular configuration having a diameter less than the minimum width of the shaft  16 . Of course, the rolled sheet  30 , under the bias imparted by its own resiliency, seeks to expand and open, so one must grasp it tightly to prevent expansion. 
     The rolled sheet  30 , while tightly gripped, is then inserted into the shaft  16  of the boot B at the upper margin  18  of the shaft  16  with the lower edge  32  of the sheet  30  leading (FIG.  4 ). Indeed, while maintained in its contracted tubular configuration the rolled sheet  30 , is lowered through the shaft  16  and between the two quarters  14  until its lower edge  32  bottoms out against the heel seat  6 . The rolled sheet  30  is rotated until the centerline X lies at the front of the shaft  16 , whereupon the grip on the rolled sheet  30  is released. The rolled sheet  30  opens under the natural resiliency of the polymer and the sheet  30  expands against the interior surfaces of the shaft  16 , (FIG.  5 ), thus forming the shape retainer A. It gives the exterior surface of the shaft  16  a smooth appearance unblemished by depressions or creases. Just as significantly, the shaft  16  remains upright over the vamp  12  and the two quarters  14 . The arcuate upper edge  34  of the sheet  30  rises above the upper margin  18  of the shaft  16 , leaving the trademark  40  exposed below that upper edge  34  and above the upper margin  18  of the shaft  16 . At this time a final adjustment in the form of a slight rotation of the shape-retainer A may be made to insure that the trademark  40  is presented forwardly and centered with respect to the vamp  12 . 
     To prolong the resiliency of the polymer of the sheet  30 , the sheet may be rolled in opposite directions upon successive uses.