Patent Application
20090320325
1. Field
Footwear.
2. Description of the Related Art
A popular casual shoe is a thong sandal. A thong sandal can be easily slipped on and off the foot. People generally wear thong sandals in warm weather (e.g., at the beach) or indoors (e.g., in a gym locker room), as the sandal exposes much of the foot. In many instances wearing a thong sandal is uncomfortable for the first time or the first several times as a person's foot must adjust to the contact between the foot and the thong strap. Although some variations of thong sandals exist, there is a need for a thong sandal that provides more comfort to the wearer.
The invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
Sole 105 at upper side 110 receives strap 120 through posts (also referred to as prongs or plugs) 220, 230, 240 that extend through to the underside of sole 210. While
Strap 120 is composed of a base piece 130 that forms the main body of the strap 120 and includes the posts 220, 230, 240 that are attached to the sole 105. Base piece 130 is a polymer material (e.g., synthetic rubber, thermal plastic urethane (TPU), thermal plastic rubber (TPR), polyvinyl chloride (PVC), or any combination of these materials, etc.). One way a base piece may be formed is by using a mold, where a polymer material in liquid form is poured or injected into the mold to set, thus creating a molded polymer strap of flexible, closed cell material. Accordingly, base piece 130 and posts 220, 230 and 240 are integrally formed as a single unit. As noted above, a strap formed solely of a polymer mold (with a hardness property of 65-70 PSI) without any added padding can cause discomfort to the foot of a person wearing the shoe because of the friction created from contact between the rubber base piece 130 and the foot. The discomfort is generally centered on areas of the foot with the greatest or heaviest contact to the strap, such as between the big toe and the second toe (in contact with a toe post of the strap) and the upper surface of the foot near the big toe and the second toe (in contact with the two main portions of the strap).
In one embodiment, the strap 120 is also composed of a padding piece 140 attached to the underside of base piece 130. Padding piece 140 provides a cushion between base piece 130 and the foot, alleviating discomfort that might otherwise be caused by friction between base piece 130 and the foot. Padding piece 140 is made of a material that provides more cushion than base piece 130, such as neoprene, ethylene vinyl acetate (EVA), cotton, organic fabric, or synthetic material (e.g., an open cell polymer or polymer gel). Padding piece 140 is thus compressible in response to the force of the foot against padding piece 140 to provide such cushion, whereas base piece 130 is generally not compressible in response to the force of the foot against base piece 130 and causes discomfort to the foot. Padding piece 140 is stitched, glued, taped, and/or fused to base piece 130. Padding piece 140 may also wrap around post 220 and may be connected to post 220 or connected to itself around the post (e.g., free ends of padding piece 140 are stitched together).
In one embodiment, base piece 130 has a body, exclusive of posts 220, 230 and 240, that has a generally uniform thickness, e.g., on the order of 0.1 to 0.25 inches. Alternatively, base piece 130 may be molded with an inset (concave) space or an underside (side intended to face sole 105) so that padding piece 140 may be placed inside the inset space of base piece 130. Collectively, the arrangement of base piece 130 having an inset and padding piece 140 form a strap of generally uniform thickness forms an even surface at the underside portion of the strap 120, with padding piece 140 not protruding or not significantly protruding from the underside surface of base piece 130. Rather, the edges of the underside surface of base piece 130 around the inset space are at an approximately equivalent surface level with padding piece 140.
Padding piece 140 may be of various sizes. In one embodiment, padding piece 140 is a single piece that covers the entire underside of base piece 130 (at the two main portions) and wraps around post 220 (the toe portion of base piece 130) that would be situated between the big toe and the second toe.
To manufacture a thong sandal, base piece 130, padding piece 140, and sole 105 are created separately and subsequently assembled. Padding piece 140 is attached to base piece 130 via stitching, gluing, taping, or fusing. Then, strap 120 (composed of padding piece 140 attached to base piece 130) is attached to sole 105 by securing posts 220, 230, 240 of the strap to sole 105. The posts 220, 230, 240 are inserted through openings 225, 235 respectively, through the entire width of the sole 105, such that the posts 220, 230, 240 are visible from the underside view of the sole 105. In one embodiment, only posts 220, 230240 of base piece 130 are inserted through openings 225, 235 and 245, respectively, of sole 105. In other words, padding piece 140 is not also inserted in or through the openings.
When a person is walking, the movement of the foot 410 causes contact between the foot 410 and the strap 120 and is particularly discomforting around the area of most friction 420. The padding of the strap 120 may cover the entire underside surface of the strap 120 (and the part of the strap 120 between the big toe and the second toe) or the padding may be limited to the portion of the strap 120 that creates the most friction with the foot 410.
The padding piece may be a single piece of various sizes. For example, the padding pieces 140, 510, 520, 560 of
The padding piece may be made of multiple padding parts. FIGS. 10-12depict padding pieces of three (530A, 530B, 530C, 540A, 540B, 540C) or five parts (550A, 550B, 550C, 550D, 550E). Further variations are recognized of different numbers of padding parts.
In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
