Operating arm for a manipulator with length adjustment by telescoping means

Claim 1

An operating arm for a manipulator with length adjustment by telescoping means having an inner structure including a number of concentric tubes for transmitting the various functions of the operating arm, said concentric tubes being rotatably supported at their upper ends by antifriction bearings which are supported coaxially and on top of each other within a transmission carriage which itself is slidably disposed in an outer tube of an upper portion of the telescoping means, and which has roller housings rotatably supported thereon and drive shafts disposed outside the center of the carriage and slidably extending through the roller housing but being operatively associated therewith so as to transmit their rotation to said roller housings while sliding therein, said roller housings having spur gear structures associated therewith, and said concentric tubes having spur gear structures at their upper ends in engagement with the spur gear structures of the respective drive shafts for rotating said concentric tubes, said transmission carriage consisting of a housing with top and bottom covers, the upper side of said top cover having one end of a chain connected thereto, said chain extending over a driven sprocket which is mounted on an intermediate support sheet arranged above the transmission carriage in the outer telescopic tube and operatively connected to an additional drive shaft disposed in the outer telescopic tube to permit upward and downward movement of the transmission carriage, said transmission carriage having a recess formed at its circumference and a counterweight slidably supported in the outer telescopic tube by means of a rail extending in axial direction through said recess and guiding said counterweight during movement thereof counter to the movement of said carriage, said counterweight being engaged with said rail by rollers and being connected to the other end of said chain.