Linear-motion telescopic mechanism and robot arm having linear-motion telescopic mechanism

A linear-motion telescopic mechanism according to the present invention includes a plurality of block members by which an arbitrary arm length is achieved in such a manner that the plurality of block member are rigidly connected to each other so as to elongate a linear-motion telescopic joint (J). On the other hand, by separating the plurality of block members one by one from a rigid alignment of the plurality of block members, the linear-motion telescopic joint (J) is contracted. The block members unfixed from the rigid alignment are still serially connected but not in a rigid manner. That is, the block members thus unfixed can be flexed in any directions, and therefore can be housed inside a support member in a compact manner. This arrangement can provide a linear-motion telescopic mechanism (i) which enhances safety by eliminating such a risk, inevitable for a typical robot arm having an elbow joint, that an object around the robot arm gets caught between arm sections when the elbow joint is closed, and (ii) which can reduce a space to be occupied by the robot arm.