Novel mechanism with a twist in the tale

Details a new type of screwing mechanical hand which has been developed. There are three distinguishing features on the structures and functions of the mechanical hand: it can perform both screwing and unscrewing automatically; it has no special driver for its finger grasp and release but adopts some specific mechanisms and structures for this process; and the preset screwing torque is used to control the release of the fingers. Describes the main parts and operating process of the hand; the structure and movements of the wrist and hand; and the principle behind the grasp and release mechanism.