Patent ID: 6299137
Filing Date: 2001-10-09
Classification: B66F,E04B,E04H,Y02A

Abstract:
An apparatus for progressively lifting a structure comprising;(a) at least two substantially identical positive displacement hydraulic pumps, each of the at least two hydraulic pumps for supplying substantially equal amounts of hydraulic fluid when driven at the same rate,(b) a power source for simultaneously driving the pumps at the same rate,(c) at least two sets of substantially identical telescoping jacks actuated by substantially identical hydraulic cylinders, each set of telescoping jacks having equal numbers of telescoping jacks including at least one telescoping jack, each telescoping jack comprising a base that supports the jack, the hydraulic cylinder of each telescoping jack mounted to the base and having a vertically extending and retracting piston rod capable of translation by a maximum stroke distance, each telescoping jack also including a series of telescoping masts mounted to the base including at least two masts, including a first mast and a last mast, the last mast mounted in relation to the base so that it can move vertically in relation to the base and the first mast mounted to the last mast so that it that can move vertically in relation to the first mast, the first mast having an attachment for attaching to a portion of the structure, a member for engaging the top end of the piston rod and a feature for locking its position to at least prevent downward movement thereof relative to the last mast, the last mast also having a member for engaging the top end of the piston rod and a feature for locking its position relative to the base to at least prevent downward movement thereof relative to the base, the first mast and its attachment bracket capable of being lifted by a distance greater than the hydraulic cylinder piston rod stroke distance if the first mast is lifted by a distance substantially corresponding to the hydraulic cylinder piston rod stroke distance and locked in relation to the last mast which is then lifted by the hydraulic cylinder in relation to the base,(d) at least two control valves that can be operated in unison for controlling the flow of hydraulic fluid that flows between each of the at least two pumps and each of the at least two sets of jacks, each of the at least two control valves hydraulically connected by hydraulic lines to one of the pumps and the hydraulic cylinders of one of the sets of jacks, each of the at least two control valves operable in at least two modes: a first mode for directing the flow of hydraulic fluid from the pump away from the hydraulic cylinders of a set of jacks so that the jacks do not raise and a second mode for directing the flow of hydraulic fluid from the pump toward the hydraulic cylinders of a set of jacks to cause the jacks to raise, so that as all of the as least two control valves are operated in unison in the second mode, all of the telescoping jacks raise at the same rate in a level fashion.