Patent ID: 8459711

Claim:
A five-fingered hand device including a hand body mimicking a human hand and a drive unit, the hand body including a base having a palm and a back, and a thumb mechanism, an index finger mechanism, a middle finger mechanism, a ring finger mechanism, and a little finger mechanism corresponding respectively to a human five fingers and each having bending and stretching functions, the drive unit driving the five finger mechanisms of the hand body independently of each other, wherein the drive unit comprises: a plurality of driven fluid pressure cylinders installed in the hand body and actuating the finger mechanisms to bend and stretch independently of each other; a plurality of driving fluid pressure cylinders placed outside the hand body and connected via fluid pressure transmission pipes to the driven fluid pressure cylinders, respectively, the driving fluid pressure cylinders applying working fluid pressures to the driven fluid pressure cylinders independently of each other; and a control unit configured to adjust the working fluid pressures transmitted from the driving fluid pressure cylinders to the corresponding driven fluid pressure cylinders, to thereby control the bending and stretching of the finger mechanisms, the thumb mechanism and one or both of the index finger mechanism and the middle finger mechanism are considered as dexterous fingers which are each provided with a force sensor configured to detect a force acting on a fingertip portion thereof and which are caused by the control unit to perform a dexterous operation including a pinching operation with the fingertips, the finger mechanisms other than the dexterous fingers are considered as force fingers which are caused by the control unit to perform a force operation including a gripping operation in response to the operation of the dexterous fingers, metacarpophalangeal joints of the four finger mechanisms other than the thumb mechanism each include a first rotary shaft having an axis line parallel to a rotary shaft of a proximal interphalangeal joint and a second rotary shaft having an axis line crossing the axis line of the first rotary shaft, the metacarpophalangeal joint of the finger mechanism considered as the dexterous finger has both rotary shafts joined to piston rods of the different driven fluid pressure cylinders separately, and the metacarpophalangeal joint of the finger mechanism considered as the force finger has only the first rotary shaft joined to a piston rod of the driven fluid pressure cylinder, with the second rotary shaft rotating freely in accordance with the force operation.