Adjustable electromagnetic vibrator

Claim 1

An electromagnetic vibrator for imparting vibrations to a materials handling device, said vibrator comprising: a housing including a base plate, a peripheral sidewall projecting axially from said base plate, and an outer plate on said sidewall near the end thereof opposite the base plate; securement means on said housing for mounting the vibrator on a materials handling device; a ferromagnetic core secured in said housing; a wire coil received on said core facing outwardly of the housing base plate and constructed and arranged for connection to a supply of pulsating electric current; a ferromagnetic armature disposed in the housing adjacent the core; a weight disposed exteriorly of the housing, adjacent the outer plate; first opening means being defined through the outer plate; first stud means extending through the opening means and connecting the weight to the armature to provide an assembly capable of reciprocating as a unit; second opening means being defined through the weight; second stud means mounted on the housing and extending through the second opening means; first compression coil spring means carried on the second stud means between the weight and the housing; securement means mounted on said second stud means on the opposite side of the weight from the housing, said securement means being mounted for adjustment toward and away from the housing; and second compression coil spring means carried on the second stud means between the weight and the securement means; whereby said assembly is counter-balanced to an adjustable level, and the securement means may be adjusted to vary said level to thereby vary the air gap between the armature and the core and coil.