Abstract: An actuation block for a train of segments, that can be used as a manual interface terminating by a finger grip (31) of the user, comprises a base (1) fixed to the hand or arm of the user and two or three motors (5, 32) oriented so that their main extension direction, or the direction of their output shaft, is parallel to a first pivoting segment (16) of the train. The actuation block is thus compact. Applications may include control arms or, on the contrary, force return arms.

Abstract: An actuation block for a train of segments, that can be used as a manual interface terminating by a finger grip (31) of the user, comprises a base (1) fixed to the hand or arm of the user and two or three motors (5, 32) oriented so that their main extension direction, or the direction of their output shaft, is parallel to a first pivoting segment (16) of the train. The actuation block is thus compact. Applications may include control arms or, on the contrary, force return arms.

Abstract: The interface consists of a sleeve (1) attached around the user's forearm and a grip element (3) comprising touch-sensitive actuators (12) which press against the tips of the fingers and thumb-actuated control buttons (13). Actuators (6, 7, 11) connect the grip element (3) to the sleeve (1) and allow to move the latter in a noticeable manner in response to impulses from the environment, and the sleeve has a wireless displacement sensor. Hence, in the best embodiments of the invention, the user avails of two very different means both for giving commands (buttons 13 and sensor 14) and for receiving a response from the virtual environment (actuators 6, 7 and 11 and the touch-sensitive actuators 12). This interface is light and easy to use. It can be used to explore virtual environments for, visiting a location, entertainment, educational purposes, et cetera.

Abstract: The linking component between two parts that contributes to maintaining them at a distance that is determined but adjustable comprises a jack with a screw and a nut. The movement of the jack is controlled by a motor. Universal joints are disposed between the two parts and the screw and the nut respectively, and the axes of rotation of one of the universal joints passes through the center of the nut. If play present in the assembly causes the screw to become skewed relative to the nut, the nut tilts freely until its axis is in line with that of the screw, thereby eliminating the flexion stresses caused by the cantilever on the screw. The component may be used to regulate the angle between two hinged sections of a robot arm.