Use of a blind rivet to retain a mechanical frame into a plastic base

Abstract

An apparatus for securing a mechanical frame to the base of a circuit breaker. The mechanical frame includes a U-shaped tab defined by first and second legs extending from the bottom of the frame. Each leg has an interior edge and an exterior edge. The interior edges of the legs are separated from one another by a predetermined distance, and at least one of the legs includes a lateral groove across its interior edge. The base includes a generally rectangular slot into which the tab is inserted. At the center of the slot is a cylindrical void extending through the circuit breaker base. A blind rivet having a head portion and a body portion, is inserted into the cylindrical void from the outside of the base such that the body portion of the rivet is between the legs of the tab. The blind rivet is then mechanically upset causing the body portion of the rivet to expand into the lateral groove in the tab and to pull the object securely toward the base. One leg of the U-shaped tab has a tang extending from its exterior edge. When the legs are spread by the force of the expanding rivet, the tang bites into the plastic base and further helps to hold the mechanical frame securely in the base.