Abstract: Apparatus includes an ignition system that repeats an ignition cycle by providing hydrogen and oxygen and also provides a control spark with a sufficient amount of energy for igniting a combustible mixture of hydrogen and oxygen. The combustion chamber is immersed in an aqueous fluid, fills with the same or other aqueous fluid, receives the hydrogen and oxygen therein, receive the control spark to ignite the combustible mixture of hydrogen and oxygen to cause a combustion reaction to occur and form steam that yields a specific amount of heat energy, and provides the aqueous fluid from the combustion chamber in response to the substantial increase in pressure on the aqueous fluid contained therein.

Abstract: Apparatus includes an ignition system that repeats an ignition cycle by providing hydrogen and oxygen and also provides a control spark with a sufficient amount of energy for igniting a combustible mixture of hydrogen and oxygen. The combustion chamber is immersed in an aqueous fluid, fills with the same or other aqueous fluid, receives the hydrogen and oxygen therein, receive the control spark to ignite the combustible mixture of hydrogen and oxygen to cause a combustion reaction to occur and form steam that yields a specific amount of heat energy, and provides the aqueous fluid from the combustion chamber in response to the substantial increase in pressure on the aqueous fluid contained therein.

Abstract: A rigid hull inflatable style boat constructed of rigid-shell modules. Modular gunwale sections are mounted to the trailing ends of a modular bow section to form the a flotation collar. Boats having greater/shorter lengths can be constructed by increasing or decreasing the number of gunwale modules. The bow and gunwale modules may be formed of molded polyethylene filled with hydrophobic foam material. The floor/hull module can be mounted at varying heights within the flotation collar to alter the performance characteristics of the craft. The hull module may have a V-shaped hydrodynamic contour, so that when the hull module is mounted relatively high within the collar the boat has a sponson-type hull form, and when the hull module is mounted relatively low within the flotation collar the boat has a V-type hull configuration.

Abstract: An exercise apparatus having foot beams (38a, 40a) rotatably mounted to an upright post member (140a) of a frame to rotate about a first axis (322). Hand levers (132a, 134a) are secured to pivot members (152a) pivotally mounted to the upright post member to rotate about a second axis (328). The hand levers are coupled by resilient linkage members (380) including elastomeric joints (382) to the foot levers so that as each foot lever rotates about the first axis, the corresponding hand lever normally rotates a related distance about the second axis. The linkage members are resiliently deformable to allow discontinuity between the rotation of the foot levers and hand levers when an exerciser exerts a differential force on the hand levers relative to the corresponding foot levers.

Abstract: An exercise apparatus having foot beams (38'",40'") rotatably mounted to an upright post member (140'") of a frame (138'"). Mounting blocks (242) are rotatably mounted to the upright post member above the foot beams to rotate about a first axis (248), and are linked by tie rods (136'") to the foot beams. Hand levers (132'" and 134'") are mounted to the mounting blocks by elastomeric torsion springs (256). Downward rotation of a foot beam results in rotation of the corresponding linked mounting block and hand lever about the first axis. Differential force exerted on the hand lever relative to the foot beam results in rotation of the hand lever about a second axis (284) and storage of energy by the elastomeric torsion spring. The hand lever is urged back to its nominal position by release of the stored energy.

Abstract: An exercise apparatus having a frame (12,22,32), a pair of foot beams (38,40) pivotally mounted to the frame, and a pair of elastomeric torsion springs (100,102) for urging each of the foot beams toward an upper position. Each of the elastomeric torsion springs comprises an annular elastomeric member (110) having a central bore (112). An outer casing (104) surrounds and is attached to the exterior surface of the elastomeric member and an inner casing (114) is disposed within and attached to the side wall of the central bore. The inner casing of each spring surrounds and is attached to a support arm (42,44) extending out from the frame of the exercise apparatus, and the outer casing of each spring is received in and attached to the side wall of an aperture (120) in a foot beam. As the foot beam is caused to rotate relative to the frame, the elastomeric member is torqued.

Abstract: An improved method for replicating a spiral groove pattern. The pattern is recorded in a photoresist layer which is then developed to reproduce the pattern in the photoresist layer. The pattern is transferred to a metal layer and formed in the surface of a plastic substrate. The improvement comprises the additional steps of asymmetrically irradiating the photoresist layer and removing the irradiated photoresist surface layer to produce a photoresist layer of uniform thickness.