Patent ID: 6379606
Filing Date: 2002-04-30
Classification: B29C

Abstract:
A method of making a part by individually thermoforming two separate sheets of thermoformable material including the steps of:successively indexing each of said two sheets in individual clamping frames mounted at different locations on a transfer structure through at least one heating station for successively heating each sheet during successive heating cycles by indexing movement of said transfer structure; indexing a first one of said sheets held in one of said clamping frames from said heating station into a forming station after undergoing a heating cycle by indexing movement of said transfer structure, and positioning said first sheet in a first tooling set including a mold and a plug assist; thermoforming said first sheet in said first tooling set into a formed first part piece; thereafter indexing a second one of said sheets and another of said clamping frames in which said second sheet is held, said another clamping frame mounted to said transfer structure at a location on said transfer structure trailing said location of said first sheet and clamping frame, said indexing occurring after said second sheet has undergone a succeeding heating cycle; positioning said second sheet in a second tooling set in said forming station including a mold and plug assist, said second tooling set offset from said first tooling set; thermoforming said second sheet in said second tooling set into a formed second part piece; the improvement wherein one of said positioning steps includes the step of shuttling one of said sheets and clamping frames by relative movement on said transfer structure from a first shifted position to a second shifted position in order to align said one of said sheets with an associated tooling set in said forming station.