Abstract: The present invention is a cylindrical linear fluid motor comprising a plurality of reciprocating rotary piston sleeve intermediate an inner coaxial hollow drive shaft and an outer coaxial cylindrical housing. Rotating disc valves at both ends of the sleeve piston control the sequential flow of high-pressure and low-pressure fluid through ports in both the drive shaft and the housing. High-pressure fluid acts on one end of the sleeve piston causing the piston to travel laterally along the drive shaft, with an inner set of roller balls in linear raceways ensuring no rotation between each piston and the drive shaft. The linear motion simultaneously affects exhausting of low-pressure fluid at the other end of the piston. Outer balls are seated in the housing and a sinusoidal circumferential raceway of each piston, to affect rotation in the piston from the lateral motion.

Abstract: The present invention is a safety jack having a propping mechanism comprised of a prop attached parallel to and jointly movable with the lifting arm, a storage well for receiving the prop in a retracted position, and a pin engagable with the prop to bias the prop and the body of the jack to prevent untimely lifting arm retraction.

Abstract: A modular toy construction system employing frictional channel connections, which supports combining an assortment of simple modular components without special tools. The system includes a series of post, panels and foundation pieces. Channels are pre-cut to allow the panels to slide into place, or for connectors to seat in the channels of adjacent pieces forming a clean joint between two channeled parts. Assembly in this fashion provides a friction fit and achieves substantial stability. This stability is present in completed and partially assembled structures, allowing whole projects or sections thereof to be moved during construction with minimal risk of structural collapse. The system supports the possibilities of a wide variety of configurations and specialty pieces, which may be added to effect distinct characteristics, features and looks.