Patent ID: 6257887
Filing Date: 2001-07-10
Classification: A61C,B29C

Abstract:
A dental hand instrument comprising;an elongated handle formed of a thermosetting plastic,a metal working tip inserted into one end of said handle,said handle having a bore provided in said one end adapted to initially accommodate a shank end of said tip under stress conditions,said shank end including a scored circumferential surface area adjacent the terminal end thereof within said bore, said scored surface being embedded into said handle by flow of the plastic material thereof into the scored surface to form a mechanical non slip connection therebetween to prevent said tip from turning during use,the thermosetting plastic material immediately adjacent said bore being bonded to said shank end free from internal stress forces,said handle and tip being subjected to heat treatment to partially melt at least the surface portion of the thermosetting plastic immediately adjacent the surface of said shank end so as to firmly secure said tip in said handle, to bind said shank end in solid plastic-to-metal contact along said shank end, and to relieve internal stress forces within the plastic material of said handle.