Waterproof shoes with thermoplastic polyurethane (TPU) insteps

This present invention describes a system of waterproof shoes with thermoplastic polyurethane (TPU) insteps, including vamp, instep and sole, in which the waterproof welt coated with waterproof glue is gummed on the seam between the vamp and the sole; the metal section, instep, mid-sole and inner welt is formed in integration by injecting with TPU polyurethane, in which the outer and inner welts are gummed with glue and sewn firmly with threads on the opposite sides of the instep; a metal piece is put between the thin bottom and the filling materials on the bottom side of the instep. The waterproof methods (the waterproof outer surface of the instep, and the waterproof welt coated with waterproof glue and gummed on the seam between the vamp and the sole reach the purpose of saving the materials and labor, obtaining the waterproof effects which is even better than those of the traditional waterproof shoes and may provide more functionality and better visual effects.

FIELD OF THE INVENTION

This present invention relates to kinds of shoe that particularly concern waterproof shoes having a thermoplastic polyurethane (TPU) instep system.

BACKGROUND OF INVENTION

Traditional waterproof shoes are usually made with waterproof materials for the vamp, and the seams are coated with waterproof glue. The inner lining comprises a sock made of waterproof materials. The seams are gummed with waterproof welts and the sock's sole is coated with a waterproof film. The inner lining may, though it is not ideal for the shoe bottom, obtain a good waterproof capacity, but the production procedure is quite complicated, time-consuming, and a waste of manpower. In view of the sewing machine process: firstly, the vamp (19) of the traditional waterproof shoes generally consists of the toe-cap, the back quarter, and the back corner; waterproof glue may be coated at the seams for better waterproof results. Secondly, the waterproof film (26) must be gummed on the sock (20) and the mid-bottom (25) after they are connected to each other, to obtain better results for the sock's bottom. In view of the formation, the production procedure of traditional waterproof shoes is very complicated. As shown inFIG. 1, there are two gaps and one line of needle holes after the vamp (19). The TPU mid-sole (24) is fixed with a steel wire and then sewn with a full line to the outer welt. Water may permeate into the shoe along the seams between the outer welts (21) and the vamp (19); first through the needle holes of the sewing lines (27) on the outer welts, then through the seams between the mid-sole (24) and the vamp (19). The water may not permeate inside the socks, but the comfort degree for wearing the shoes would be seriously affected.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide kinds of waterproof shoes with a new type of combined waterproof system to avoid the defects of the current process.

For the above-mentioned purpose, the following process scheme shall be used in the present invention.

A kind of waterproof shoe having a thermoplastic polyurethane instep system comprises a vamp, an instep, and a sole. The importance is that the waterproof welt is gummed on the seam between the vamp and the sole and coated with waterproof glue. The metal section, instep, mid-sole and inner welt are formed by integration by injection with polyurethane (PU). The TPU shell and welt are stitched together. The thin mid-sole having a plurality of holes is stitched onto the flange of the welt. The shell with mid-sole attached is put into a mold and material containing PU is poured into the mold to form the outsole. The outer and inner welts are gummed with glue and sewn firmly with threads on the opposite sides of the instep. A metal piece is put between the thin bottom and the filling materials on the bottom side of the instep.

The said inner welts are substantially square-shaped.

The vamp and the top of the instep may be sewed with 18K machine after they are coated with glue.

The whole inner sock (lining) is waterproof in the traditional waterproof shoe. By the present invention, it is charged that the inner sock for the vamp above the instep is waterproof, and the outer surface of the vamp is made of waterproof materials, with their seams being covered with waterproof glue. The outer layer of the instep shall be waterproof. The seams between the vamp and the instep shall be gummed with the waterproof welts and coated with waterproof glue. The said method(s) shall conserve materials and manpower, while obtaining even better waterproof results than those of the traditional waterproof shoe, and may further produce more functionality and better visual effects.

Some specific characteristics of the present invention:1. The bottom edges of the shoe side and the mid-sole are formed by integration with no seams on the sole bottom, thus increasing the waterproof function.2. The design for the appearance is creative and innovative, and is a breakthrough from the traditional waterproof shoe.3. The outer welts are sewn directly to the TPU welts, formed by injection, with threads, which shall be better in tensile strength.4. The materials of the instep have better grease resistance, acid resistance and alkali resistance than those of the normal rubber. The material also has better bending resistance and is not easily broken.5. It shows the design idea “regarding the human as the foundation”. The embodiment of the present invention is comfortable and safe for wearing in the winter with improved cold resistance, thermal insulation, and wear-and-tear resistance.

These and other embodiments of the present invention are further made apparent, in the remainder of the present document, to those of ordinary skill in the art.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

The structural diagrams of an important part of the detailed description of the present invention are shown inFIG. 2AandFIG. 2B, referring also toFIG. 3andFIG. 4. The procedure of making said instep of said waterproof shoes comprises of first sewing a vamp (10) to an instep (1) with an 18K machine. Next, a waterproof welt is gummed onto the sewing seams and coated with a waterproof glue. A sock (11) is then stuck firmly to said vamp (10) and instep (1) by a coating of glue. A metal section (2) is placed within the instep (1) and integrated with mid-sole (13) and the inner welt (12) by injection with TPU. The outer welts (3) and inner welts (12) are gummed on the opposite sides along said instep (1). The outer welts (12) are sewn tightly to said inner welts with the thread (4). Filling materials, such as an EVA (5) are placed under the bottom side of said mid-sole (13). A metal piece (6) and a thin rubber bottom (7) are placed under said filling materials. The thin rubber bottom (7) and the outer welts (3) are sewn tightly to the outer side of the welts with the full line (8). Furthermore, the outsole (9) which may be made of various materials is stuck onto the thin bottom. This method shall obtain better waterproof effects than those of the traditional waterproof shoes, which conforms to the ergonomic principles. Two important points in the production procedure are described below:(1) The waterproof welts should be stuck on the seams between the instep (1) and the vamp (10), and then coated thoroughly with waterproof glue.(2) Do not damage the mid-sole when sewing said welts.

An embodiment of the present invention is an instep system, as shown inFIGS. 5-9, comprising a shell50having a built in ply rib51(FIG. 5), a welt60(FIG. 6), a filler material61to provide support to an article of footwear, a steel shank63for stability in a heel area, a mid-sole70stitched onto welt60(FIG. 7), and an outsole80(FIG. 8). Shell50comprises an upper portion and a connecting bottom portion. Shell50may be made of TPU material. Ply rib51is configured about a perimeter of a bottom side of shell50. Welt60is stitched to ply rib51. Welt60may be made from a polyvinyl chloride (PVC) material or other thermoplastic material. Filler material61may comprise of Ethylene-vinyl acetate (EVA) or other elastomeric materials. Filler material61is cemented into place on an outside bottom portion of shell50. Steel shank63is secured in place on top of filler material61at a location about a heel area, as shown inFIG. 6. Mid-sole70is attached to a flange of welt60to secure filler material61and steel shank63in place. Mid-sole70has holes71to allow polyurethane (PU) material to pass through and fill gaps between mid-sole70and bottom portion of shell52.

In an embodiment of the present invention outsole80is integrally molded with shell50, as shown inFIG. 8. Shell50is placed in a mold and PU material is poured to form outsole80. The PU material flows through holes71in mid-sole70filling the space between mid-sole70and bottom portion of shell52not occupied by filler material61.

In another embodiment, a removable insole90, as shown inFIG. 9, may be inserted into an interior of shell50for added comfort for the user.

Another embodiment of the present invention is a method of making an instep system. The method, as shown inFIG. 10comprises the steps of: forming a shell made of TPU material100, attaching a welt to the ply rib110, securing filler material to outside bottom portion of shell120, attaching steel shank on top of filler material at a location about a heel area130, stitching mid-sole onto the flange of welt140, forming outsole by placing shell in a mold and pouring PU material into the mold150.

Two important points in the production procedure are described below:

(1) The welts are coated thoroughly with waterproof glue.

(2) Care should be taken not to damage the mid-sole when sewing said welts.

In traditional waterproof shoes, the whole of inner socks are the main waterproof part. Now it is changed. In the present invention, the inner socks of the vamp above the instep are the main waterproof part, and the outer vamp is made of waterproof materials. Waterproof glue is coated onto the seams. The outer instep is waterproof for the whole instep part. Waterproof welts are gummed to the seams of the vamp and the insteps, and waterproof glue is coated onto them. Said methods save materials and manpower, and thus obtain even better waterproof results than those of traditional waterproof shoes at a lower cost.

Throughout the description and drawings, example embodiments are given with reference to specific configurations. It will be appreciated by those of ordinary skill in the art that the present invention can be embodied in other specific forms. Those of ordinary skill in the art would be able to practice such other embodiments without undue experimentation. The scope of the present invention, for the purpose of the present patent document, is not limited merely to the specific example embodiments of the foregoing description, but rather is indicated by the appended claims. All changes that come within the meaning and range of equivalents within the claims are intended to be considered as being embraced within the spirit and scope of the claims.