| 主权项 |
1. An implantable treatment device adapted to be fixed or interlinked to bone, which generates unidirectional progressive movement by a member generating reciprocating motion in the same direction, using friction based means allowing unidirectional movement, the means allowing unidirectional movement comprising a second member disposed adjacent to an inner rod or an outer tube, the second member, or the inner rod or the outer tube, having a tapered portion having a slanted surface, wherein the tapered portion expands in the direction of movement of the inner rod or the outer tube, and wedge means disposed between the slanted surface of the second member, or the inner rod or outer tube, and a planar surface of the second member, or the inner rod or outer tube, extending parallel to the direction of movement of the inner rod or outer tube, the wedge means being selected from a group consisting of rolls, balls, barrel-shaped members or sprags, each wedge mean individually forming a line contact with the second member, or the inner rod or outer tube at a contact site with the line contact being substantially non-parallel to the direction of movement, wherein friction due to movement of the inner rod or the outer tube causes the wedge means to move to a first position of greater distance between the slanted surface and the planar surface when the inner rod or the outer tube is moved in the direction of movement, thereby allowing movement of the inner rod or outer tube in the direction of movement, and causes the wedge means to move to a second position of lesser distance between the slanted surface and the planar surface when the inner rod or the outer tube is moved against the direction of movement, thereby wedging the wedge means between the slanted surface and the planar surface at the line contact and preventing movement of the inner rod or outer tube against the direction of movement. |
