Abstract: A Level Floor Room Extension for expandable and retractable rooms in vehicles employs a subfloor movable from a horizontal stored position beneath the vehicle floor, through an intermediate horizontal position, to an elevated horizontal position, to provide a continuously level floor extending from the interior vehicle floor, over the subfloor, to the slide out room floor.

Abstract: A Level Floor Room Extension for expandable and retractable rooms in vehicles employs a subfloor movable from a horizontal stored position beneath the vehicle floor, through an intermediate horizontal position, to an elevated horizontal position, to provide a continuously level floor extending from the interior vehicle floor, over the subfloor, to the slide out room floor.

Abstract: An extendable room comprises accordion type ceiling and wall panels which fold within panel covers when the room is retracted, thereby taking up much less interior space and leaving the interior of the primary structure just as attractive, albeit smaller, as prior to retraction. The wall and ceiling panels are hinged together with tongue and groove connections and are secured in the flat, extended configuration by steel cables running through the panels. The side walls also include windows which may be made clear and opaque electronically. The secondary floor is retractable below the floor of the primary structure when the room is retracted, permitting the room extension floor to become the primary floor.

Abstract: An apparatus for extending and retracting one structure with respect to another which utilizes a pivoting mechanism rather than the standard linear mechanisms known in the art. The mechanism further utilizes a torsion bar connected between the distal ends of the actuator for synchronizing the movement of the actuators to prevent binding and twisting. A first embodiment utilizes a flat chain and a pair of circular guides to maintain the torsion bar in a horizontal plane, while a second embodiment of the invention utilizes a four-bar linkage system.

Abstract: An apparatus for extending and retracting one structure with respect to another which utilizes a pivoting mechanism rather than the standard linear mechanisms known in the art. The mechanism further utilizes a torsion bar connected between the distal ends of the actuator for synchronizing the movement of the actuators to prevent binding and twisting. A first embodiment utilizes a flat chain and a pair of circular guides to maintain the torsion bar in a horizontal plane, while a second embodiment of the invention utilizes a four-bar linkage system.

Abstract: An apparatus for synchronizing the extension and retraction of linear actuators. A quadrilateral structure is formed by means of the support base, a pair of actuators, and a crossmember, with a sensor positioned so as to detect variations in the shape of the quadrilateral. The sensor functions in cooperation with the actuator control mechanism to vary power to the actuators in response to the changes in shape which occur due to slight variations in actuator speed of movement.