Joining together metal and plastic parts - by positioning e.g. aluminium@ casting in mould and e.g. injecting thermoplastic polymer to fill space and shrink onto lugs when cool

摘要

One metal and one plastic component are joined together, partic. in the open roof of a car, by means of a linkage with two parts; the first part is formed on the metal component which is positioned in a mould for it; the plastic is then cast so that the second part is produced engaging the first. Injection moulding can be used instead of casting. ADVANTAGE - Method eliminates the problems of earlier methods namely having to produce an additional link pin, needing to produce holes and the pin to close dimensional tolerances etc. In an example, of members of an open car roof system an arm (8) is first produced e.g. by pressure die casting in aluminium. It is then placed in an appropriate injection mould to produce the operating member (6) of e.g. polyoxymethylene or polyamide and the polymer is injected to fill the cavity. Linkage pins (14,15) projecting from both sides of the arm (8) and integral with it (8) are thus polymer-coated also. The member (6) shrinks upon cooling so that holes (11,12) in the member (6) provides a seating for the pins (14,15), and the arm (8) is permanently fixed between the member (6) and attachment (13).