Patent ID: 7384265

Claim:
An orthodontic force mechanism, comprising: an elongated jack screw having a pair of end portions, at least one of which is threaded, and a central spindle section between the end portions, which spindle section has at least two radial holes therein; a pair of nut housings mounted on the end portions of the jack screw, at least one of which is threadedly coupled to a threaded end portion of the jack screw; and a lock mechanism mounted on the central spindle section, which lock mechanism includes a detent configured to engage an end opening of each of the radial holes in the spindle section when such hole is in alignment with the detent, such that the spindle cannot rotate relative to the lock mechanism when the detent is inserted into a hole, and is free to rotate relative to the lock mechanism when the detent is clear of a hole, wherein the detent can be moved out of engagement with a hole using a tool inserted into that hole from its opposite end such that a distal end of the tool pushes the detent out of the hole, wherein the lock mechanism comprises a housing having an outwardly opening recess and a bearing surface in engagement with the jack screw, wherein a spring is disposed in the recess and confined for compression between the detent and the housing.