Shock absorbing post assembly for crutch and bicycle seat applications

Abstract

A shock absorbing post assembly includes an outer tube, inner shaft, guide elements, and spring member. The outer tube has an exterior surface with circumferential portions along an outer cylinder encompassing the outer tube and outer races formed longitudinally between opposite ends of and spaced apart circumferentially about the outer tube. The outer races are within the outer cylinder between and inwardly of the circumferential portions of exterior surface. The inner shaft is received in and partially extends above the outer tube and has an exterior surface with circumferential portions along an inner cylinder encompassing the inner shaft and inner races formed longitudinally between opposite ends of and spaced apart circumferentially about the inner shaft in alignment with outer races of the outer tube so as to provide pairs of aligned outer and inner races. The inner races are within the inner cylinder between and inwardly of the circumferential portions of the exterior surface of the inner shaft. Guide elements are between and extend within pairs of aligned outer and inner races so as to permit reciprocatory sliding movement of the inner shaft relative to the outer tube and thereby allow the inner shaft to extend from and retract into the outer tube between extended and depressed positions. The spring member is disposed in the outer tube below the inner shaft so as to yieldably support the inner shaft at the extended position relative to the other tube while permitting the inner shaft to retract into the outer tube toward the depressed position in response to the post assembly receiving a shock impact thereon.