| 摘要 |
<p>A method of making a sound projector of unitary construction for a vehicle horn. A projector body (12) and projector cover (14) are molded of heat weldable plastic material as complementary parts to provide a unitary structure when the parts are joined together. The body (12) is molded with a spiral wall member (28) which defines an open channel (18) extending from a central opening (22) in the body (12) to a bell (24) at the outer peripheral turn. The wall member (28) is formed with one or more wall edges which are of substantially uniform thickness and which are adapted to be engaged by flat surfaces (52, 54) on the cover (14). The cover (14) is placed on the body (12) and the parts are subjected to relative rectilinear vibration to friction weld the parts together at the interface.</p> |
