| 摘要 |
A folding wheelchair comprises a framework, a seat and a backrest mounted on said framework. Two front caster wheels permit steering and two large rear wheels permit propulsion. The framework comprises two symmetrical lateral rectangular frames mounted to be moved away from or brought back toward each other by a jointing device, each lateral rectangular frame comprising at least one lower and one upper horizontal side-bar spaced by one front and one rear vertical side-bar. The jointing device comprises a compass-member having two legs whose outer ends are rotatively mounted around two parallel supporting pins, each of which is disposed within the corresponding lateral frame of the framework. Two pieces of canvas are provided, which are parallelly stretched between the lower and the upper horizontal side-bars of the lateral frames and are located on opposite sides of the compass, one of these pieces of canvas comprising the seat. One of the legs of the compass comprises a shoulder located at a pivotal joint between the legs, the shoulder overlapping and abutting a portion of the end of the other leg when the compass-member is extended, whereby the shoulder limits the extending movement of the compass. The shoulder abuts that other leg when the legs have passed over-center upon extension of the compass, the tension in the canvas preventing unwanted collapse of the compass. |
