| 摘要 |
817,913. Welding by electric heating. PFAFF A. G., G. M. Jan. 4, 1957 [Jan. 12, 1956], No. 380/57. Class 39(3) [Also in Groups VIII and XXII] A machine for uniting or sealing thermoplastic sheet material includes an electric heating unit 9 which may be swung from the non-operative position shown to a position in which a V-shaped heater element 16 formed of sheet material is positioned between a feed guide 6 and pressure rollers 3, 5. The element 16, which has recesses 20 resulting in a more effective heating of the apex portion of the V, may be mechanically strengthened by a ceramic filler. Current supply terminals 14 are connected to the element by parallel strips 10 which may be of copper, the unit also consisting of insulating members 13, 19 and metal side plates 11. The element may be secured to the connection strips 10 by clamping, welding or riveting. Pressure welding of ductile metal sheets or foil with or without thermoplastic coating is also specified. |
