| 摘要 |
810,742. Electric heating. BULL, J. March 18, 1957 [May 29, 1956], No. 16616/56. Class 39(3) A tool for the heat sealing of plastic film comprises a rigid plate 1 of insulating material and a handle 2 incorporating a trigger-operated switch which controls the power supply to a heater tape 3 extending along the front edge of the plate. The tape extends into slots at the plate sides and is connected to terminal plates 4, and spring- loaded plungers 9 keep the tape taut. In operation the tape is fed with a low voltage and is pressed against the layers of film to be sealed. The tool may be associated with foot pedal means which operates the heater circuit and brings the tool into contact with the plastic films. |
