OUTSOLE

Abstract: An outsole (10) comprising a sole component (14) of moldable material molded around an insert (12), which forms at least a portion of the wear surface of the outsole (10). The insert is cut (18), cement is applied to one surface, and, thereafter rigidly placed, cemented surface up, within a mold into which is injected the moldable material at elevated temperature. The moldable material flows around, and, in cooling, adheres to the insert in the mold.

Description: OUTSOLE Background of the Invention This invention relates to inserts in the tread surfaces of outsoles. It is well known in the art to provide inserts 5 in the wear surfaces of outsoles to thereby impart to the outsole various desirable characteristics, e.g., water proofing, cushioning, flexibility, increased friction, etc. It is desirable to enhance the adherence of such inserts to the remainder of the outsole and to 10 reduce the steps necessary in the manufacturing of such outsoles. Summary of the Invention In general, the invention features an outsole comprising a first sole component of oldable material, 15 and at least one other sole component around which is molded the first sole component, the other sole component forming at least a portion of the wear surface of the outsole. In its method aspect, the invention features . 20 cutting an insert component, applying an adhesive to the one surface of the insert component, rigidly securing the insert component within a mold with the one surface facing upward, closing the mold, and injecting moldable material, at elevated temperature into the mold, thereby ■• 25 allowing the moldable material to flow around and, in cooling, adhere to, the insert component. In preferred embodiments the moldable material is thermoplastic rubber; the insert component is open cell crepe rubber; the surface of the insert component 30 opposite the one surface is deskidded prior to insertion of the insert component in the mold; the insert component is uniformly approximately between 1/4 and 3/16 of an inch thick; and the durometer value of the insert component is greater than that of the moldable 35material. OMPI . ~VΫIFO V fa i. Rl.'A Other advantages and features of the invention will be apparent from the following description of the preferred embodiments thereof, and from the claims. Description of the Preferred Embodiment The structure and manufacture of the preferred embodiment of the invention will now be described, after first briefly describing the drawings. Drawings Fig. 1 is- a plan view of the wear surface of an outsole embodying the invention. Fig. 2 is a sectional view taken at 2-2 of Fig. 1. Fig. 3 is an isometric view of the upper surface of said outsole. Fig. 4 is an enlarged isometric view of a portion of the tread component of said outsole. Structure and Operation Referring to Figs. 1-3, outsole 10 has open-cell crepe rubber insert 12 (uniformly 1/4 to 3/16 of an inch thick) , surrounded by thermoplastic rubber (TPR) sole component 14. As shown, the upper surface of sole component 14 includes a plurality of apertures 16 which provide weight reduction and some shock absorption, as described in the application of Vijay K. Batra, "Outsole", Serial No. 270,795, filed June 1, 1981, in the United States Patent and Trademark Office. As shown in Figs. 1 and 4, insert 12 has transverse slits 18, formed in the manner described in U.S. Patent Nos. 3,124,986, 2,206,860 or 2,284,309, which extend inwardly of the wear surface of the insert, but which do not extend throughout its thickness. Advantageously, not only do slits 18 improve the anti-slipping properties imparted to the sole by the open cells 20 of the crepe rubber, but the weight of the sole is reduced by the presence of apertures 16. ΦxTzE _ OMP \$- > 7 ■ V I? Manufacture The outsole is made by first cutting, from a sheet of open-cell crepe rubber (uniformly approximately 1/4 to 3/16 of an inch thick) , one surface of which has been deskidded by slitting as described above, the piece to be used as insert 12. The unslit surface of insert 12, is then cleaned using a chlorinating solution (such as 3212 Upaco Satrate) , and thereafter, there is applied to that surface a suitable cement (e.g., Upaco 2108 or 3801) , which is allowed to dry. For Upaco 2108 or 3801, a minimum drying period of 8 hours in ambient conditions should be allowed, the preferred period being 16 hours. Should any warpage or distortion of insert 12 occur as a result of the application of the cement, the insert may be warmed to approximately 75°-90°F, to enable manual or mechanical restoration to its original shape. After cementing, insert 12 is placed, with the unslit cemented surface upward, in a mold (not shown) , having any conventional means for retaining the insert in a predetermined position within the mold, and having portions to produce apertures 16 in the upper surface of the heel portion of sole component 14. Having secured the insert in position in the mold, the mold is closed, and liquid TPR (e.g. E hart FM 72), at a temperature of approximately 300°F and at a pressure of approximately 3001bs per square inch, is injected thereinto by conventional means. After being injected into the mold, the TPR is allowed to cool and solidify for approximately 90 seconds, after which period the mold is opened, and outsole 10 removed. The preferred ranges for durometer values for the crepe rubber and the TPR are, respectively, 72-75 and 50-55. The durometer value for the crepe rubber must be such that, upon injection under pressure of the TPR into the mold, there is substantially no distortion of the crepe rubber insert. The heat and liquid state of the TPR, as it is introduced into the mold causes the adhesive to mix with the TPR, and, together, they flow to some degree, into the open cells 20 of the sides and upwardly facing surface of insert 12> thereby effecting an excellent bond between sole component 14 and insert 12. Secure bonding is particularly important at junction 22, around the tread surface perimeter of insert 12 which is subjected to significant stress, through flexion, when the outsole is in use. Further, the bonding of insert 12 to sole component 14 during the process of molding the TPR, eliminates a separate bonding step, thus reducing production costs. Other embodiments are within the following claims. For example, sole component 14 may be of any material capable of being molded as described above, e.g., PVC, polyurethane, or vulcanized rubber; insert 12 may be cut from a non-deskidded sheet of crepe rubber and the deskidding applied to the insert before its insertion into the mold or after the removal of outsole 10 from the mold; and deskidding may be accomplished by means other than slitting.

Claims: Claims 1. An outsole comprising a first sole component of moldable material, and at least one other sole component around which is molded said first sole component, said other sole component forming at least a portion of the wear surface of said outsole. 2. The outsole of claim 1 wherein the wear surface of said other sole component is deskidded. 3. The outsole of claim 1 wherein said first sole component is thermoplastic rubber. 4. The outsole of claim 1 wherein said other sole component is open cell crepe rubber. 5. The outsole of claim 1 wherein said other sole component is uniformly between 1/4 and 3/16 of an inch thick. 6. The outsole of claim 1 wherein the durometer value of said other sole component is greater than that of said first sole component. 7. The outsole of claim 1 wherein a rim of said moldable material surrounds said portion to define said wear surface. 8. The outsole of claim 7 wherein said rim is substantially coplanar with said portion. 9. The outsole of claim 2 wherein said deskidding extends fully across the area of said wear surface of said other sole component. 10. A method of manufacturing an outsole, comprising cutting an insert component, applying an adhesive to one surface of said insert component, rigidly securing said insert component within a mold with said one surface facing upward ' , closing said mold, and injecting moldable material, at elevated temperature, into said mold, thereby allowing said moldable material to flow around, and, in cooling, adhere to, said insert component. _0 11. The method of claim 10 wherein said adhesive is allowed to partially cure prior to said insert component being placed in said mold. 12. The method of claim 10 wherein the durometer value of said insert component is greater than 5 that of said moldable material. 13. The method of claim 10 wherein said insert component is open cell crepe rubber. 14. The method of claim 10 wherein said moldable material is thermoplastic rubber. 20 15. The method of claim 10 wherein the surface of said insert component opposite the said one surface is deskidded prior to the insertion of said insert component in said mold. 16. The method of claim 15 wherein said 25 deskidding is applied to a sheet of material, from which said insert component is cut, prior to said cutting of said insert component.

Inventors: DEAN NORMAN, DEAN, NORMAN
Applicants: SPERRY TOP SIDER INC, SPERRY TOP-SIDER, INC.
Application year: 1983
Main classification: A43B13
IPC codes: A43B13, B29D31