APPARATUS FOR WELDING PARTS FROM POLYMERIC MATERIALS Russian patent published in 1994 - IPC

FIELD: welding of parts from polymeric materials. SUBSTANCE: apparatus has welding unit, forming die mounted centrally of welding unit and multiple-position table with spring-biased forming punches. Inner and outer welding punches are loosely mounted on forming punches for restricted displacement in vertical plane. Welding unit mounted on movable cross-piece is made in the form of inner and outer hollow punches. Punches are mounted concentrically with respect to forming die opposite welding punches mounted on multiple-position table. Outer and inner punches are made from materials having different coefficients of heat passage. Inner welding punches are provided with mechanism for controlled feeding of heat flux to welding zone. Inner welding punch mounted on movable cross-piece is loosely positioned between forming die and outer welding punch. Apparatus is further provided with cutting die which is rigidly mounted on multiple-position table concentrically with respect to outer welding punch. Outer surface of outer welding punch, which mounted on cross-piece, is spaced from inner surface of cutting die edge by distance equal to 1/40-1/60 of thickness of parts to be welded. Working surfaces of forming die, forming punches and inner welding punches are covered by anti-adhesion coating. Working surfaces of outer welding punches are covered with titanium nitride coating. Forming die and forming punches are provided with cooling system. EFFECT: high quality of welding parts. 4 cl, 11 dwg