Patent ID: 6893006

Claim:
A multi-speed drop leg mechanical jack for use with a trailer, the jack comprising: first and second housing seections telescopically moveable relative to each other, said first housing section connected to said trailer to be raised or lowered; a drop leg in non-geared sliding engagement with said second housing section and selectively engageable therewith along a range of telescopic positions so as to be engagable with the ground; a drive mechanism for creating telescopic movement between said first and second housing sections so as to raise or lower said object relative to the ground; a gearbox mounted to said first housing section, the gearbox comprising: a gear housing having an inner surface defined by gear housing teeth; a plurality of planet gears, each of the plurality of planet gears having teeth, the teeth in meshing engagement with the gear housing teeth; a planetary carrier connected to the plurality of planet gears, the carrier having an inner surface defined by planetary carrier teeth; a sun gear having sun gear teeth, the sun gear axially slideable between a working high gear in which the sun gear teeth are in meshing engagement with the planetary carrier teeth and a working low gear in which the sun gear teeth are in meshing engagement with the teeth of the plurality of planetary gears wherein the working high gear and the working low gear each have a turns per inch (TPI) parameter and each of the TPI parameters is selected at least in part to complement the drop leg; and wherein said drive mechanism utilizes said gearbox to provide said working high gear or said working low gear to support loads encountered during the raising or lowering said trailer.