Patent Application
20130125420
This invention relates to shoes generally, more particularly to shoes with comfortable fit features that adjust to the size of the foot.
Shoes are made in many sizes, for men, women and children. Since feet sizes vary remarkably between individuals, commercially available, ready-to-wear shoes are made in numerous sizes. These sizes vary from sizes 3.5 to 15 for men, sizes 5 to 13.5 for women and sizes 5 to 13 for children. In order to find a reasonable semblance of custom-fit for the customers, shoe manufacturers make all shoes in all of the above sizes and often in ½ sizes. Even with such a wide variety of sizes of available shoes, often the wearer will find their shoes not fit perfectly. This is due to the fact that not only the length of their feet but also the width will determine how well they tolerate the shoes. In the case of children, the growth in size of their feet, commensurate with their overall growth often makes the parents' task of finding a good fit daunting. And, they will necessitate frequent replacement with larger and larger size shoes.
The present invention addresses all of the above issues adequately. By providing expandable (but still sturdy) stretches of elastic material at strategic locations in the top portion of the shoes, it is anticipated that only a few sizes of shoes will be necessary for all age groups and both genders. It is further anticipated that a vast majority of adults will fall within one medium size; this is so because it is easy with this invention to expand sufficiently to accommodate a significant range of feet sizes.
Prior art patents on shoes as in EP1529456 teach an expandable orthopedic type shoe that expands to accommodate a swollen foot.
In U.S. Pat. No. 3,404,468 a shoe has stitching moved inward forming somewhat of a U where the sides join the sole wherein the foot is able to expand widthwise. This patent is called “Moccasin Shoe” and it provides for expandable width and a comfortable feeling due to the fact that the leather upper is attached to the sole inboard of the edges so that the shoe can stretch. None of these shoes provides a way for the shoe to adjust to accommodate larger sizes because they fail to provide expansion upward, sideways and lengthwise.
An expandable shoe has a top portion, a pair of side portions, a back portion, a sole, a heel and a first elastic member. The first elastic member joins the top portion to the pair of side portions at a critical location which is at the junction of the top portion and the side portions. The first elastic member is in the shape of an inverted “U” extending along the front of the shoe. The expandable shoe may further have a second elastic member joining the back portion to the side portions at the critical locations at the junctions of the back and side portions and the junctions of the back and the rear of the sole. The second elastic member is in the shape of an upright “U”.
Preferably, the heel is adjustable to be positioned in various positions along the rear of the shoe. The heel location on the sole is adjustable to match the stretched shoe length. The sole may have a joint slidable to allow the length of the shoe to increase. The sole has an interlocking surface mating with a complimentary interlocking surface on the heel to fix the heel location on the shoe. The heel and sole are affixed together at the interlocking surfaces and clamped together by a fastener.
The first elastic member is stretchable to allow the shoe to move in the length, width or height directions in response to the size of the foot.
The second elastic member is stretchable to allow the rear of the shoe to move in the width or length direction in response to the size of the foot.
The expandable shoe can be made of a leather or any suitable upper construction material including the top portion, side portions and back portion. The first elastic member is made of a braided elastic material. The braided elastic is a composition of polyester and rubber. The second elastic member is made of a braided elastic material. The first elastic member can stretch a distance at least twice its unstretched width or length. Similarly, the second elastic member can stretch a distance at least twice its unstretched width or length.
The invention will be described by way of example and with reference to the accompanying drawings in which:
With reference to
With reference to
In each of the embodiments,
The stretched version of the shoe is illustrated in
An optional, but important aspect of the present invention has a heel 40 that is adjustable that can be positioned in various positions along the rear of the shoe 10. The heel 40, as shown, is fastened by a male threaded fastener member 50 to a female fastener member 60 affixed to the underside of the shoe 10 in the sole 18 as shown in
While the shoe 10 as defined in the exemplary embodiment has a leather upper construction of the various components of the one or more sides 14, top 12 and back 16 of the shoe 10 it is also understood that synthetic materials and/or cloth or woven materials could be used in conjunction with the stretchable elastomeric members 20, 30. The bottom of the shoe 10 preferably can be a combination of rubber heel and sole or leather sole and rubber heel, it makes no difference to the inventive features of the shoe 10 which material is chosen for the sole 18.
It is preferred that both the front inverted “U” 20 and the rear vertical “U” 30 be made of an elastic material that is strong yet stretchable, one example being a braided elastic material. These braided elastic materials are manufactured using a composition of materials such as polyester and rubber and are available in many colors and widths. Braided elastic is often used in waistbands, sleeves, necklines and leg bands. This kind of elastic is also used in casings. It becomes narrower when sewn through as the needle pierces the rubber causing a loss of stretch or recovery. This is an important phenomenon in that the present invention preferably utilizes sewn seams so that it can create non-stretch zones in the location of the stitching or weaving to the tops and sides of the elastomeric material. This non-stretch zone provides a secure attachment of the inverted and vertical “U” members 20, 30 to the other parts of the shoe 10. The elastomeric members 20, 30 can be folded or doubled up in the stitch areas if so desired to provide additional stiffness and strength in the regions of attachment. Preferably, however, the overlap of the elastomeric members 20, 30 is such that multiple stitching can be applied. When the elastomeric members 20, 30 are attached they are designed in such a way to be shrink resistant and to stay unaffected by chlorine or salt water which makes them an attractive addition to a shoe in that they can be made in a variety of colors and patterns that greatly enhance the visual appearance of the shoe 10. However, this elastic material can be made very durable and strong so that it can easily provide the necessary performance needed in a shoe. The stretch zone provided between the joined top 12 and sides 14 or the sides 14 and back portion 16 of the shoe 10 is dependent on the elastomeric member 20 or 30 and can enable the shoe 10 to increase by at least two sizes. This stretch can be facilitated by providing more or less stretch within the elastic material such that the stretch can be more or less dependent on the performance requirements of the shoe 10. It is important that the shoe 10 fit snugly on the wearer's foot and not too loosely that it becomes uncomfortable during normal wear. To accomplish this, the selection of the elastic material must be such that it has a proper amount of stretch, however, is not so stretch-resistant that as the foot swells, the elastic material will resist so strongly that it is uncomfortable to wear. To balance this, adjustments must be made in the elastic material so that it has the proper amount of stretch over a proper amount of distance to accommodate an adjustment in shoe size. Ideally, as illustrated in the various embodiments, the braided material will stretch at least two times its length. Accordingly, if two shoe sizes are needed and the two sizes are greater than a half an inch, then the stretch must be able to accommodate half an inch to increase for an example in length. Accordingly, the stretch can be adjusted smaller so that less stretch is provided, these things are tunable and the shoe can be made in such a fashion that it may only adjust one size, or preferably, two or more sizes by the type or amount of elastic material used between the various components. This and the stretchability of the members 20 and 30 provides for the increase in shoe size.
While the shoe in the illustrated embodiments shows a front portion as an inverted “U” with a combination with a rear portion and an adjustable heel, it is understood that the shoe could be manufactured with only the front portion expandable or only the rear portion expandable. In such a case, the expandable rear portion preferably is as shown in
Variations in the present invention are possible in light of the description of it provided herein. While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is, therefore, to be understood that changes can be made in the particular embodiments described, which will be within the full intended scope of the invention as defined by the following appended claims.
