Patent ID: 6630094
Filing Date: 2003-10-07
Classification: E05D,Y10T

Abstract:
A method of making a tear-resistant, flexible hinge structure comprising the steps of:a) providing a hard, flat metallic platen; b) placing a heat resistant, non-conductive barrier sheet on said platen; c) providing a metallic conductive die having at least three parallel rows of alternating projections and intervening depression therebetween, wherein said rows of alternating projections and intervening depressions are arranged in staggered relationship whereby each projection is contiguous to 2, 3, to or 4 depressions, and each depression is contiguous to 2, 3, to or 4 projections; d) providing a pressure producing structure over said metallic platen, and control means therefor to advance said pressure producing structure towards said metallic platen and to withdraw said pressure producing structure away from said metallic platen; e) securing said metallic conductive die to said pressure producing structure; f) providing heating means to heat said metallic conductive die to a predetermined temperature when it is in place on said pressure producing structure; g) providing a source of radio frequency energy, and connecting it between said metallic conductive die and said metallic platen; h) placing at least a strip of flexible plastics sheet material from which said flexible hinge structure is to be formed, on said barrier material; i) pre-heating said metallic conductive die to a temperature of 160Â° F. to 200Â° F.; j) advancing said pre-heated metallic conductive die against said flexible plastics material so as to contact the same with pressure; k) providing stop means to assure that said pre-heated metallic conductive die does not advance so far as to contact said barrier material but advances to a distance away from said barrier material which is less than the original thickness of said flexible plastics material; l) after step (j) has continued for a first predetermined period of time, turning on said source of radio frequency energy for a second predetermined period of time; m) after said source of radio frequency energy has been turned off following step (l), permitting said metallic conductive die to remain in place for a third predetermined period of time; n) withdrawing said metallic conductive die away from said barrier material and said flexible plastics material so as to reveal a formed flexible plastics hinge structure having at least three parallel rows of alternating flat and raised portions; and o) permitting said formed flexible hinge structure to cool.