| 摘要 |
1,264,418. Seaming non-metallic sheet material. BRANSON INSTRUMENTS Inc. 24 June, 1969 [3 July, 1968], No. 31766/69. Heading B5K. Two thermoplastic members 20, 22 which are superposed to define an interface 26 are bonded together by engaging an exposed face 21 of the member 20 with a sonically or ultrasonioally vibrating tool 16, urging the tool 16 into the member 20 until the frontal surface 30 thereof is disposed in proximity to the interface 26 whereby to cause, responsive to the dissipation of (ultra)sonic energy, molten thermoplastic material 40, 42 to flow at the interface between the members 20, 22, and permitting the molten material to harden. The members 20, 22 may be made of acrylonitrile - butadiene - styrene plastics material and are positioned on a support 24. The tool 16 is made of aluminium or titanium and forms a mechanical amplitude transformer fitted to a piezoelectric or magnetostrictive transducer connected to an electrical high-frequency generator. The tool 16 is formed with a projection 31 extending coaxially from an annular stop member 34 and having an axial length substantially equal to the thickness of the member 20 but may be slightly less than or greater than this dimension. An annular recess 32 is provided in the tool 16 to accommodate softened thermoplastic material displaced by the projection 31. After cessation of the vibrations, the tool 16 is temporarily retained in its inserted position whilst the material 40, 42 hardens. The tool 16 produces a spot weld in the form of a blind 46, Fig. 4, surrounded by an annular bead 44. |
