Tokyo-TECH 100 N Hand : Three-fingered eight-DOF hand with a force-magnification mechanism

This paper presents Tokyo-TECH 100 N Hand, a three-fingered eight-degree of freedom hand that can generate a large grasp force of 100N. All fingers are 90 mm in length and the weight of the hand is 941 g. The hand can generate a large grasp force with a force-magnification mechanism whereas all joints can perform a high speed motion of over 200 deg/s with a high-speed driving mechanism. The high-speed driving mechanism consists of a feed screw and nut with a low reduction ratio. We propose a simple and small three-dimensional toggle mechanism for the force-magnification mechanism. The toggle mechanism thrusts the feed screw and nut of the high-speed driving mechanism when the finger is in contact with an object. It can maintain a large grasp force without energy consumption. We experimentally verify the force and speed performances.