Patent ID: 7040056

Claim:
A gear shaft assembly for actuating linear movement of an object attached thereto, the gear shaft assembly comprising a lower channel assembly, the lower channel assembly comprising: (a) a threaded rod; (b) a first gear adjacent an end of the threaded rod; (c) a second gear engageable with the first gear and attached to the end of the threaded rod; (d) a mechanism for driving the first gear against the second gear; (e) at least one threaded journal bearing threaded on the correspondingly threaded rod; (f) at least one bearing housing supporting the at least one journal bearing; (g) a movable carrier arm mounted on the threaded rod and attachable to the object; wherein, when the mechanism for driving the first gear against the second gear is activated, the first gear drives the second gear, rotating the threaded rod, and moving the carrier arm on the threaded rod.