Patent ID: 7423392
Filing Date: 2008-09-09
Classification: B60S

Abstract:
1. A trailer jack system for engaging ground to raise and support a trailer, said trailer jack system comprising, in combination: an electric linear actuator securable to the trailer and having an electric motor; wherein the electric linear actuator includes a vertically extending housing, vertically extending leg coaxially extending and retracting from a bottom of the housing to engage and disengage the ground, and a mounting bracket for securing the housing to the trailer; wherein a total travel of the electric linear actuator includes a free travel portion when linear actuator is disengaged from the ground so that the electric linear actuator is unloaded and a work travel portion when the linear actuator is engaged with the ground so that the electric linear actuator is loaded; a source of electric power operably connected to the electric motor; a controller operably connecting the electric motor and the source of electric power so that a first voltage is automatically supplied to the electric motor when the electric linear actuator is traveling in the free travel portion and a second voltage is automatically supplied to the electric motor when the electric linear actuator is traveling in the work travel portion; an operator input switch which can be released while the electric linear actuator is traveling in the free travel portion and the electric linear actuator will continue to travel in the free travel portion but the input switch must be continuously depressed while the electric linear actuator is traveling in the work travel portion in order for the electric linear actuator to continue traveling in the work travel portion; and wherein the first voltage is greater than the second voltage.