(under subclass 15) Subject matter wherein the holding device or anchor has a chamber therein, and expansion is caused by fluent pressure applied within the chamber.
SEE OR SEARCH THIS CLASS, SUBCLASS:
391, for an externally threaded fastener element (e.g., a bolt or screw) having fluent pressure separating means.
434, for an internally threaded fastener element (e.g., a nut) having plural moveable parts moved by fluent pressure.