Induction heating appts. for plastics extruder

摘要

An induction heating appts. for plastics extruders employs induction coils with E-shaped cores. The coils are mounted in a 2-piece housing which is clamped on the extruder barrel by spring tension. The extruder barrel (1) is heated by induction coils (2,2a,3,3a) in which the coil is wound on the central arm (4,4a,5,5a) of an E-shaped laminated iron core. The coils are magnetically coupled to the barrel by an interlayer (6,6a,7,7a) which covers the core. Pairs of coils are mounted in a 2-piece housing (8,9) which is assembled and clamped on the barrel (1) periphery by means of threaded pins (13), carrying washers (15) and nuts (16,17). Disc spring stacks (14) are interposed between the washers (15) and housings (8,9), so that the housings and coils are urged into contact with the barrel by spring pressure. In another embodiment, the appts. may be adapted to a cylindrical extruder barrel.