Patent ID: 6896704
Filing Date: 2005-05-24
Classification: A61F,B25J

Abstract:
1. A movable finger for at least one of a plurality of fingers of a prosthesis, comprising: a base disposed between a one of a back and a palm of a hand and between an instep and a sole of a foot; a first intermediate portion having a rear end swingably connected to a tip of the base through a first support shaft; a second intermediate portion having a rear end swingably connected to a tip of the first intermediate portion through a second support shaft; and a fingertip having a rear end swingably connected to a tip of the second intermediate portion through a third support shaft, wherein an actuator to pull one end of a first thin string member is disposed in the base, an eccentric member is disposed in a connected portion between said base and said first intermediate portion, the eccentric member being supported by said first support shaft so as to be rotated with respect to said base and said first intermediate portion and having a winding portion of an inconstant distance from the first support shaft, said first thin string member is passed through a finger inner side of said first support shaft and wound on said winding portion of said eccentric member, the other end of the first thin string member is connected to a portion of said eccentric member on a side, where said winding portion is separated from said first support shaft, the portion of said eccentric member is connected to a portion of said first intermediate portion which is closer to the tip of the first intermediate portion than said first support shaft through a first intermediate portion pulling spring, and a first intermediate portion straightening spring is inserted between said first intermediate portion and said base to always urge the first intermediate portion to take a straightened posture with respect to said base, thus constituting a first intermediate portion bending mechanism, a pulley wound with a second thin string member disposed in said first intermediate portion so as to be moved in a longitudinal direction thereof, one end of the second thin string member is connected to said base through a finger outer side of said first support shaft, the other end of the second thin string member is connected to the portion of said eccentric member on a side separated from the first support shaft, a third thin string member, one end of the third thin string member being connected to a support shaft of said pulley, the other end thereof connected through the finger inner side of said second support shaft to a portion of said second intermediate portion closer to the tip of the second intermediate portion than said second support shaft, and a second intermediate portion straightening spring is inserted between said second intermediate portion and said first intermediate portion to always urge said second intermediate portion to take a straightened posture with respect to said first intermediate portion, thus constituting a second intermediate portion bending mechanism, and a fourth thin string member, one end of the fourth thin string member being connected through a finger outer side of the second support shaft to a portion of said first intermediate portion closer to the rear end of the second intermediate portion than said second support shaft, the other end thereof connected through a finger inner side of said third support shaft to a portion of the fingertip closer to the tip of the second intermediate portion than the third support shaft, and a fifth thin string member, one end of the fifth thin string member being connected through a finger inner side of the second support shaft to the portion of said first intermediate portion closer to the rear end of the second intermediate portion than said second support shaft, the other end thereof connected through a finger outer side of the third support shaft to a portion of said fingertip closer to the tip of the second intermediate portion than the third support shaft, thus constituting a fingertip bending mechanism.