The present invention relates generally to casters, and more particularly to, casters having springs to absorb shock and vibrations.
Casters have been employed to protect loads being transported by motorized or non-powered material handling equipment from damage due to rough and uneven surfaces, and obstacles that strike the caster wheels. Shock from obstacles or uneven surfaces may be greatly reduced by using spring loaded casters. The shock dampening effect of spring loaded casters reduces wear on the wheel, caster and conveyance as well. Noise may also be greatly reduced when spring loaded casters are used.
Typically, a spring loaded caster may be a swivel or rigid caster where the wheel and axle assembly is supported with two or more springs to absorb shock and vibrations caused by uneven surfaces, foreign objects and other irregularities of the wheel-engaging surface. Once the spring loaded caster encounters any interference, the springs are compressed so as to absorb the shock, which protects the load from possible damage or sliding off the conveyance.
In one embodiment of the present invention, a pivotable spring loaded caster includes a support plate adapted to be affixed to the underside of an article to be transported. A swivel bearing assembly is attached at a top side to the underside of the support plate. Two caster legs depend downwardly from the rotatable portion of the swivel bearing assembly. The caster legs are spaced apart and preferably substantially parallel with each other. Each of the caster legs includes an elongated slot for receiving an axle. A pair of spring brackets is provided that are of a generally L-shaped configuration and are disposed on an outer surface of a corresponding caster leg. The spring bracket may include a wear plate.
A spring sleeve is disposed on the underside of one leg of each of the spring brackets. Additionally, two or more spring block assemblies are provided. Each spring block assembly includes an axle-receiving segment that includes a passage for receiving an axle therethrough. On each spring block, a spring is held in place by a spring pin and is received in the corresponding spring sleeve. A wheel is provided in the space between the caster leg and an axle that holds the various parts components together is threaded through the spring block assemblies, caster legs, and the wheel.
In an alternate embodiment, the rigid spring loaded caster is provided which lacks the swivel bearing assembly of the first embodiment of the present invention. Instead, the two caster legs depend downwardly from the underside of the support plate. Preferably, in this alternate embodiment, first and second wear plates are provided on each of the spring brackets.