Abstract: Articulated support arm apparatus for use by an operator which comprises a base and first and second arms supported by said base. A work device is supported by said arms. A dual axis joint interconnects said first and second arms. The joint is movable between locked and unlocked positions. In the unlocked position the work device is movable by the operator to a desired position and in a locked position the work device is held in a predetermined position.

Abstract: A foot retaining strap for a swim fin having a pocket for receiving a wearer's foot. The strap includes a spring laced through a molded neoprene heel pad for comfort. The ends of the springs are secured to opposite sides of the foot pocket opening of the swim fin. The wearer's foot is held in the pocket under tension of the spring which holds the foot pad against the wearer's heel. Overstretching of the spring is prevented by a nonstretchable cord strung inside the spring, with the ends of the cord also affixed to the sides of the fin. The length of the cord is such that it prevents the spring from being stretched beyond its elastic limit.

Abstract: A gauge for measuring pressure is described having a casing, a transparent lens, a faceplate bearing indicia and indices, a primary depth pointer, a maximum depth pointer, and a rack-and-pinion gear assembly for moving the pointers relative to the indicia and the indices. In the rack-and-pinion gear assembly there is provided a spring-biased rack, a pinion gear and a flexible diaphragm. The pinion gear is mounted on a shaft supporting the primary depth pointer. The rack is threadably coupled to the gear and adapted to be moved linearly for turning the gear and the shaft. The diaphragm is mounted in a selected manner in a bore in the casing in contact with one end of the rack. The opposite end of the rack is in contact with a spring. A change in ambient pressure relative to the pressure within the casing moves the diaphragm and rack against the spring and rotates the pointers. The maximum pressure indiciator, which is driven by the primary depth pointer, is provided for indicating maximum pressure.

Abstract: A decompression analog computer and indicator includes an ambient pressure sensing chamber exposed to hydrostatic pressure as experienced by the diver. The pressure in sensing chamber produces a flow of fluid between the sensing chamber and a pair of parallel connected second chambers via the intermediary of first and second diffusion membranes introducing a delay to simulate different tissues of the body. Each of the second chambers has a movable wall portion operatively connected to a spring biased pressure responsive indicating piston. The indicating pistons move to and fro in a track overlying at indicating scale visible to the diver. The indicators indicate uptake and release of nitrogen by different tissues within the body and indicate to the diver when decompression is necessary.