Snap-in means for mounting electrical devices or the like in a support panel aperture

Claim 1

In a toggle switch assembly adapted to be snap-in mounted from the back of a panel through a hole in the panel and having an insulating base housing switch contacts, a switch frame covering the base, and a pivotal toggle lever for actuating the switch contacts, wherein the improvement comprises an elongated bushing extending from said switch frame and pivotally supporting said toggle lever, said bushing having an outer end portion adapted to be inserted into the panel mounting hole, a helical garter spring having an outermost toroidal diameter and a helical diameter, said outermost toroidal diameter being larger than the diameter of the panel mounting hole when said garter spring is in its normally expanded state, an annular groove in said bushing outer end portion for retaining said garter spring to form a subassembly including said garter spring and said bushing outer end portion, said groove having an upper portion for retaining said garter spring in its normally expanded state, a lower portion of sufficient radial depth to receive said garter spring, when squeezed radially inwardly to a compressed state of reduced toroidal diameter without reducing said helical diameter, wherein said subassembly can pass through the panel mounting hole, and an inner wall inclining radially inwardly and downwardly from said upper portion to said lower portion, and biasing means adapted to urge said bushing in an axial direction away from the back of the support panel after mounting, whereby during insertion of said subassembly as a unit into the panel mounting hole, the outer helical surface of said garter spring engages the back rim of the hole and said garter spring is thereby squeezed to said compressed state in said groove lower portion and, as the approximate center of said garter spring moves past the front rim of the hole, said garter spring thereafter is guided along said groove inner wall, as it expands toward its normally expanded position, to said groove upper portion where a portion of the outer helical surface of said garter spring engages the front rim of the hole and is held thereagainst by said biasing means.