method of ultrasonic welding of a sheet of thermoplastic elastic material on a part must be thermoplastic material.

摘要

A method of ultrasonically welding a sheet 8 of flexible thermoplastics material to a body 5 comprising a rigid thermoplastics material comprises placing the rigid body 5 on a first member 10, positioning the flexible sheet 8 on that part of the rigid body to which the sheet is to be welded, applying a second member 11 to the flexible sheet, which member 11 is provided with a multiplicity of projections 12, preferably pyramid-shaped, for engagement with the part of the body covered with the sheet, and emitting ultrasonic vibrations between the two members 10, 11 while an appropriate pressure is exerted on the pieces to be welded. As described, the body 5 is a bar to be supported in an aperture in a sun visor having two flexible thermoplastic skins 7, 8. After welding the skin 8 to the bar 5, the sun visor is turned over and the skin 7 is welded to the bar 5. Surplus material is cut away along joins 13, 14. In a modification, (Figure 5), both skins are joined to the bar in a single operation by providing both members with projections (12a). IMAGE