| 主权项 |
1. An apparatus comprising:
a shaft having a proximal end, a distal end, and a helical surface located at the distal end; a housing which rotatably receives the proximal end of the shaft, wherein the housing includes a locking mechanism in communication with an internal engagement mechanism wherein the internal engagement mechanism is connected to the proximal end of the shaft, wherein the locking mechanism is movable such that the locking mechanism can be located in a first position which locates the internal engagement mechanism such that the internal engagement mechanism is located in a free position allowing the housing to rotate freely relative to the shaft in response to rotating the housing in both directions, wherein the locking mechanism is movable such that the locking mechanism can be located in a second position which engages the internal engagement mechanism such that the internal engagement mechanism prevents rotation of the shaft relative to the housing in at least one direction; and an attachment point, wherein the attachment point is connected at a proximal end of the housing. |
