Abstract: An all-plastic, swivel caster assembly has horn and stem molded as a homogeneous unit of plastic. A wheel of molded plastic or plastic-rubber combination, supports the assembly. In one version, the horn sidewalls have fingers forming keyhole-shaped slots receiving grooved end portions of a plastic axle borne by the wheel. The axle retaining fingers normally secure the axle in the horn, but are sufficiently resilient to enable intentional removal of the wheel and axle assembly from the horn without tools, for cleaning. In another version, the horn sidewalls have apertures receiving a plastic axle which has a head on one end and a circumferential groove at the other end. An axle cap located at the outside face of one horn sidewall has a slot received on the axle groove, and retains the axle in assembly. The cap has a detent boss received in a detent recess in the horn sidewall to keep the cap, and thereby the axle, in place.

Abstract: The legs of a swivel caster assembly horn are mounted to a pair of horizontally-spaced beam plates which are pivoted to the legs ahead of the swivel axis. The caster wheel is mounted on an axle behind the swivel axis. A pair of urethane springs is mounted to the horn legs ahead of the pivot axis. A bolt across the front ends of the beams receives collars, each collar having a threaded transverse aperture which is screwed onto threads on the lower ends of bolts whose upper ends have heads with flanges which bear downward on a spring cap plate bearing downward on the tops of the springs, whereby the load on the caster horn is applied by lever action to the springs which are pre-loaded by the collars screwed onto the bolts.