US Patent 7438506 Jack for carrying and installing mine panels

A jack includes a base, a guide extending from the base, and an extensible member having an extensible fit with the guide and extending from the guide to have a free end. A support is located at the free end of the extensible member. An actuator is capable of extending the extensible member. The guide and extensible member have portions which are laterally offset with respect to the base and the support such that when the support is in pressure engagement with a panel, the laterally offset portions are disposed adjacent one side of the panel to leave an area between opposite sides of the panel substantially unobstructed.