Encapsulated fastener and method and tooling for manufacturing same

Abstract

An encapsulated fastener includes a nut adapted to receive a bolt. The nut is encapsulated by an encapsulation including an extension, which includes a tube adapted for receiving a portion of the bolt and a flange adapted for engaging a face of the nut. The encapsulation extension is placed on the nut in an overmolding tool, wherein an encapsulation base is injection molded over a portion of the encapsulation extension. The encapsulation base encapsulates the nut, except for its bore, which is sealed off during the overmolding process by a spring-mounted mandrel. Alternative embodiments of the invention include tubes with different configurations for contacting the bolt whereby the tube or cylinder is reinforced. A method and tooling for manufacturing the encapsulated fastener are also provided.

1 . An encapsulated nut, which comprises:
 a nut with first and second faces, an internally-threaded bore extending between and open at said faces and at least one sidewall;   an encapsulation extension including a tube with proximate and distal ends and a tube bore open at said proximate end and generally aligned with said nut bore;   said encapsulation extension having a flange located at said tube proximate end and engaging a respective nut face;   an encapsulation base encapsulating said nut, said flange and said tube proximate end, said encapsulation base having an opening at the other face of said nut, said opening providing access to said nut and tube bores;   said nut having a shoulder at said nut face; and   said encapsulation base having a foot extending into said nut shoulder.