A jig for progressive welding of lap joints in thermoplastic webbing - for rapid mounting of fittings without mechanical damage

摘要

Loop ends are made in thermoplastic webbing by welding a lap joint formed by doubling back the end of the webbing and passing the interface progressively between pressure rolls located beneath a heating jet. The heater is a radiant gas or electric element located between heatsheilds to prevent overheating of adjacent parts of the webbing: pref. the distance between the heater and the roll nip is variable. One of the rollers is power driven and the nip pressure is adjustable. Used for securing buckles or other fittings more rapidly and reliably than by use of stitched or rivetted joints and without weakening the webbing by local perforations.