US Patent 7909074 Floor engaging device for workbench

A workbench includes a wheel device secured to a work table, four floor engaging extremities attached to the work table, four rotary members rotatably attached to the work table and engaged with the floor engaging extremities respectively for adjusting the work table up and down relative to the floor engaging extremities, and a coupling device for coupling the rotary members together and for allowing the rotary members to be rotated relative to the floor engaging extremities simultaneously and thus for allowing the work table to be adjusted up and down relative to the floor engaging extremities simultaneously. A hand wheel may be coupled to the coupling device for operating the coupling device.