Abstract: A hydraulic system maintains squareness while extending an object via two lift cylinder assemblies. A hydraulic circuit is connected to the cylinder assemblies, and includes synchronizer with multiple isolated chambers corresponding to the cylinder assemblies, a rod extending axially through the chambers, and pistons mounted on the rod and associated with the isolated chambers. The hydraulic circuit operably connects a pump to the synchronizer and to the cylinder assemblies for controlling and providing synchronized movement of the cylinder assemblies. The hydraulic circuit includes valving for an automatic re-synchronization cycle, fill cycle, and air purge cycle. The system is effective for moving large objects in a non-binding manner, such as an extendable room on a recreational vehicle, while maintaining accurate squareness.

Abstract: A lift table maintains levelness while lifting a support surface via two or more lift cylinder assemblies. A hydraulic circuit is connected to the cylinder assemblies, and includes synchronizer with multiple isolated chambers corresponding to the lift cylinder assemblies, a rod extending axially through the chambers, and pistons mounted on the rod and associated with the isolated chambers. An axial passageway extends continuously through the rod and is connected to first passageways for communicating hydraulic fluid to one side of the chambers. The hydraulic circuit operably connects a pump to the axial passageway of the synchronizer and to second passageways connected to the chambers and to the cylinder assemblies for controlling and providing synchronized movement of the at least two lift cylinder assemblies. The hydraulic circuit includes valving for an automatic re-synchronization cycle, fill cycle, and air purge cycle.

Abstract: A lift table maintains levelness while lifting a support surface via two or more lift cylinder assemblies. A hydraulic circuit is connected to the cylinder assemblies, and includes synchronizer with multiple isolated chambers corresponding to the lift cylinder assemblies, a rod extending axially through the chambers, and pistons mounted on the rod and associated with the isolated chambers. An axial passageway extends continuously through the rod and is connected to first passageways for communicating hydraulic fluid to one side of the chambers. The hydraulic circuit operably connects a pump to the axial passageway of the synchronizer and to second passageways connected to the chambers and to the cylinder assemblies for controlling and providing synchronized movement of the at least two lift cylinder assemblies. The hydraulic circuit includes valving for an automatic re-synchronization cycle, fill cycle, and air purge cycle.