Patent ID: 7621356
Filing Date: 2009-11-24
Classification: B60D,B60S

Abstract:
1. A trailer jack comprising: (a) a mounting bracket adapted to be secured to a tongue of a trailer, the mounting bracket includes a U-shaped flange plate adapted to be clamped to the trailer tongue, the flange plate having a cylindrical stub attached to a planar surface thereof, the cylindrical stub including a plurality of bores extending diametrically therethrough, a tubular sleeve affixed to the tubular housing of the jack screw and adapted to receive the cylindrical stub therein, the tubular sleeve having a diametric bore formed therethrough and alignable with a selected one of the plurality of bores in the cylindrical stub, and a pin adapted to be inserted in aligned bores in the sleeve and stub; (b) a jack screw having an outer tubular housing and an inner tubular member concentrically disposed in the tubular housing with means for longitudinally displacing the tubular housing relative to the inner tubular member and with the mounting bracket affixed to the outer tubular housing; (c) a shroud secured to the lower end of the inner tubular member, the shroud having an axle journaled in bearings at a lower end of the shroud, the axle supporting a pair of wheels in side-by-side relation along with a first sprocket of a relatively large diameter affixed to the axle; (d) at least one shaft supporting a second sprocket of a relatively small diameter compared to the diameter of the first sprocket and said at least one shaft being journaled for rotation in the shroud, the one shaft being parallel to said axle; (e) an endless chain deployed about the first sprocket and the second sprocket; and (f) means for applying a torque to the one shaft.