Expandable shoe

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”.

TECHNICAL FIELD

This invention relates to shoes generally, more particularly to shoes with comfortable fit features that adjust to the size of the foot.

BACKGROUND OF THE INVENTION

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.

SUMMARY OF THE INVENTION

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” which substantially follows the outer periphery along the edges of the sole continuously from the front of the sole extending along the sides spaced by the side portion. 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.

DETAILED DESCRIPTION OF THE INVENTION

With reference toFIGS. 1A-8B, the expandable shoe made according to the present invention is illustrated. The shoe10as shown is in the style of a men's loafer. This is an exemplary embodiment illustrating the various design features of the inventive concept. It is understood that the shoe could be made in any number of styles in men's, women's or children's shoes. The shoes can be laced or otherwise slipped on as illustrated. The inventive concept is not limited to the exemplary shoe as illustrated but is provided only for purposes for defining the unique structure of the shoe as it relates to the various components which enable it to expand from an unstretched relaxed version by two or more shoe sizes in terms of length, width and height as required to accommodate various sizes of feet.

With reference toFIG. 1A, the shoe10is shown in a perspective view wherein the shoe10is relaxed and unstretched. As illustrated, the shoe10has an upper leather portion in the exemplary shoe embodiment. This upper leather portion has a top portion12, one or more side portions14and a back portion16. Connected to the upper leather portion is a sole18and a heel40. In addition, the expandable shoe10has a first elastic member20that joins the top portion12to the one or more side portions14at the junction of the top portion12and the side portions14. The first elastic member20is in the shape of an inverted “U” extending along the front of the shoe10rearwardly. As shown inFIG. 1A, in the rear portion of the shoe10there may be a second elastic member30which joins the back portion16to the one or more side portions14at the junction between the back portion16and the side portions14. This elastic member30is further attached to the rear of the sole18. In this fashion the second elastic member30is in the shape of an upright “U” as illustrated.

In each of the embodiments,FIGS. 1A,2A,3A,4A,5A,6A and7A the shoe10is shown in its unstretched or relaxed position. As shown in the side view ofFIG. 2A, phantom lines exterior of the shoe are provided that show how the shoe10can be stretched two or more shoe sizes in terms of length and width as well as height. This feature is accommodated in the front portion by the elastomeric member20. As shown, the elastomeric member20overlaps a portion of the side portions14and extends over the top12slightly. This provides a stretching zone that enables the top12connected to the one or more sides14of the shoe10to be affixed securely on the upper edges of the sides. The sides14along the bottom edges being attached directly to the sole18of the shoe10as is normally done, but the one or more side portions14are allowed to flex and stretch outwardly and lengthwise to accommodate larger feet and the top12affixed to the first elastic member20can move vertically.

The stretched version of the shoe is illustrated inFIGS. 1B,2B,3B,4B,5B,6B and7B. As can be seen, the shoe10, in the stretched version can stretch lengthwise, widthwise and heightwise as clearly illustrated in the various figures. As shown inFIG. 3B, the first elastomeric member is the inverted “U” which is directly spaced by the side portions and over the sole outer edges along the front and the sides of the shoe. As shown, the opening for the foot is spaced behind the first elastomeric member.

An optional, but important aspect of the present invention has a heel40that is adjustable that can be positioned in various positions along the rear of the shoe10. The heel40, as shown, is fastened by a male threaded fastener member50to a female fastener member60affixed to the underside of the shoe10in the sole18as shown inFIGS. 8A and 8B. As initially shown inFIG. 4A, the heel40is positioned such that it is secured against the sole18shown illustrated with the fastener50located in the slot52. When the heel40is moved rearwardly as illustrated inFIG. 4B, a gap54is created along each side of the heel40. Portions41of the heel40are fixed and provide lateral support as does the rear of the slidable heel portion42as illustrated inFIGS. 4A and 4B. As the fastener50is clamped, this heel portion42is securely affixed to the bottom of the shoe10. In order to accommodate the locking of the heel40to the bottom of the shoe10serrations53,55are provided that interlock. These complimentary locking serrations53and55enable the heel portion42when moved from the position shown inFIG. 8Awhich is a normal relaxed unstretched shoe of the smallest size to a larger size shown inFIG. 8Bto be locked in that position. When the heel40has the portion42moved rearwardly and secured by the fastener50as illustrated inFIG. 8Bthe serrations55are gapped to accommodate the lengthening of the shoe10in the rear portion16. This feature enables the shoe10to maintain a very stable base for the wearer so that his heel is fully supported and not overhanging the rearward portion of the heel40. The vertical shaped “U” is shown inFIGS. 6A,6B,7A and7B allow the shoe10to expand in a widthward direction at the rear of the shoe10shown best inFIG. 3Band also to extend lengthwise as best shown inFIG. 8B. This expansion of the rearward portion of the shoe10in conjunction with the forward expansion of the shoe10allowed by the first elastomeric member20means that the combination of the first and second elastomeric members20and30enable the shoe10to expand at least two or more sizes in terms of length and width dependent on the size of the foot. This advantageously allows the shoe10to fit comfortably and securely as the upper leather portions are secured to the sole18of the shoe10while the elastomeric members20,30provide a means for which the shoe10can expand and stretch so it will comfortably fit the foot as either the foot grows in the case of children or in the case of swelling of the foot due to an injury. Ideally the shoe10is purchased such that it fits under the normal conditions; however, as the foot size increases due to growth or injury the shoe10will expand to accommodate this.

While the shoe10as defined in the exemplary embodiment has a leather upper construction of the various components of the one or more sides14, top12and back16of the shoe10it is also understood that synthetic materials and/or cloth or woven materials could be used in conjunction with the stretchable elastomeric members20,30. The bottom of the shoe10preferably 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 shoe10which material is chosen for the sole18.

It is preferred that both the front inverted “U”20and the rear vertical “U”30be 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” members20,30to the other parts of the shoe10. The elastomeric members20,30can 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 members20,30is such that multiple stitching can be applied. When the elastomeric members20,30are 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 shoe10. 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 top12and sides14or the sides14and back portion16of the shoe10is dependent on the elastomeric member20or30and can enable the shoe10to 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 shoe10. It is important that the shoe10fit 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 members20and30provides 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 inFIGS. 2A and 2Band throughout the various embodiments with only a rear portion and the shoe could be manufactured normally without the addition of the expandable front portion if so desired. This may be helpful in women's shoes and or youth shoes wherein an expandable front portion may not be desired. Alternatively, the rear portion may be fixed and the front portion simply expandable and all these various combinations are well within the scope of the invention as claimed. In addition, due to the nature of the shoe10, as the shoe expands more than one size it was determined that the heel40preferably should be adjustable. This feature may or may not be necessary depending on the amount of stretch that is being attempted by the expandable shoe10. If, for example, the front portion of the shoe expands but not the rear, the heel40can be fixed and not adjustable. On the other hand, if the rear portion of the shoe10is adjustable, it is believed preferable the heel40be adjustable. Alternatively, if in fact the heel portion is not adjustable and rear portion is allowed to be expandable it is understood that the shoe10may slightly overlap the heel40. For this reason, it was determined that the heel40, in most occurrences, should be movable along with the rear portion. These and other alternative combinations are possible with the shoe10.