Abstract: A robot having an arm and an adapted actuating mechanism of a parallelogram construction, formed of vertical arms having the forward and rearward movement regulated within a fixed range, parallel rods having the up and down movement regulated within a fixed range, upper links and a forward horizontally extending horizontal arm is supported by side plates. At least the above mentioned vertical arms are provided with an X-axis driving device and the parallel rods are provided with a Z-axis driving device and means to balance the load of the work and arm mechanism.

Abstract: A parallelogram arm assembly having a vertical arm for suspending a load at lower end thereof and a pair of horizontal arms one of which is guided in a horizontal path is provided. The other horizontal arm is guided in a vertical path. The paths are defined in a supporting structure which is mounted rotatably on a standard or the like. Apparatus, such as a piston/cylinder actuator is provided for maintaining in cooperation with the parallelogram a floating balanced state of the arm assembly independently of the loaded or no-load state.