| 摘要 |
An improved disc brake plastic piston (11) has a metallic cap or face (19) which provides a means of attaching a brake shoe or a brake shoe assembly, or provides a dust boot groove, or, in a most preferred mode, the metallic cap component provides both a brake shoe retaining means and a dust boot groove. The piston is comprised of a cylindrical plastics body having an open end (15) and a closed end (13). At least one ring bead (17) can extend from the wall of the piston body contiguous to, or near, the open end. The bead or beads are suitably ejector beads utilized in the molding operation. The metallic cap (19) extends over the end wall of the open end of the cylindrical body and is secured to the body by being snap fitted or clamped over the ring bead. Alternative means for anchoring the metallic cap may be provided, such as by crimping the interior lip of the metallic cap or by providing threads on the internal or external walls of the piston adjacent to the open end of the piston, and corresponding or matching threads on the metallic cap. <IMAGE> |
