CASTER CAPABLE OF GETTING OVER STEP

摘要

PROBLEM TO BE SOLVED: To solve the problem that it is desirable to realize a caster that can get over a step, which is most difficult in operating an instrument such as a wheelchair and a carriage that carries and moves a person and an article, and can be easily and safely operated by anyone and mounted on a wheel chair, a carriage and the like, which are commercially available.SOLUTION: An auxiliary wheel assembly 4 for getting over a step is provided at a front position of a caster type front wheel 8. Because the auxiliary wheel assembly 4 gets caught in a step 9 when using only the front wheel 8 and the auxiliary wheel assembly 4 and therefore cannot get over the step 9, a link mechanism 12 is provided between a screw for fixing a front wheel part and a portion for revolving the front wheel. In the front wheel 8 is provided a front wheel cover 19 and arranged the auxiliary wheel assembly 4 constituted of an auxiliary wheel 1, an auxiliary wheel 2, an auxiliary wheel frame and a return spring 23 for the auxiliary wheel assembly, with a B shaft 6 at a front part of the front wheel cover 19 as a fulcrum. Even if the auxiliary wheel assembly 4 gets caught in the step 9, centers of gravity of a wheelchair, a carriage and the like are retreated by retreating and floating up the front wheel 8 and the auxiliary wheel assembly 4 by oscillation of the link mechanism 12, allowing the wheelchair, the carriage and the like to easily get over the step 9.