Abstract: A jet propulsion device and method for controlling movement of the jet propulsion device, where liquid inlets are positioned at a distance from the surface of the device. Preferably, the inlets are positioned in the stabilizing fins of the device. When the device reaches a certain speed, a Riabouchinsky cavity forms around the device, and the radius of the Riabouchinsky cavity is substantially equal to the distance between the inlets and the longitudinal axis of the device.

Abstract: A jet propulsion device and method for controlling movement of the jet propulsion device, where liquid inlets are positioned at a distance from the surface of the device. Preferably, the inlets are positioned in the stabilizing fins of the device. When the device reaches a certain speed, a Riabouchinsky cavity forms around the device, and the radius of the Riabouchinsky cavity is substantially equal to the distance between the inlets and the longitudinal axis of the device.

Abstract: An outboard motor assembly for use as external propulsion for a watercraft includes a drive assembly, a shaft assembly, and an impeller-jet assembly coupled to the shaft assembly. The impeller-jet assembly includes an inlet stator, an exit stator, an impeller, and an external housing surrounding the stators and impeller. The inlet stator contains a plurality of blades, forcing the flow of water into an optimum direction for the impeller. The exit stator also contains a plurality of blades, which are configured to direct the flow from the impeller, removing the twist and resulting in a more efficient flow of water. The exit stator is tapered such that each blade is thicker at the trailing edge than at the leading edge, to create a circular array of separate nozzles with gaps between them.

Abstract: An outboard motor assembly for use as external propulsion for a watercraft includes a drive assembly, a shaft assembly, and an impeller-jet assembly coupled to the shaft assembly. The impeller-jet assembly includes an inlet stator, an exit stator, an impeller, and an external housing surrounding the stators and impeller. The inlet stator contains a plurality of blades, forcing the flow of water into an optimum direction for the impeller. The exit stator also contains a plurality of blades, which are configured to direct the flow from the impeller, removing the twist and resulting in a more efficient flow of water. The exit stator is tapered such that each blade is thicker at the trailing edge than at the leading edge, to create a circular array of separate nozzles with gaps between them.

Abstract: An outboard motor assembly for use as external propulsion for a watercraft includes a drive assembly, a shaft assembly, and a impeller-jet assembly coupled to the shaft assembly. The impeller-jet assembly includes an inlet stator, an exit stator, a impeller, and an external housing surrounding the stators and impeller. The inlet stator contains a plurality of blades, forcing the flow of water into an optimum direction for the impeller. The exit stator also contains a plurality of blades, which are configured to direct the flow from the impeller, removing the twist and resulting in a more efficient flow of water. The exit stator is tapered to create a more efficient flow of water. The center portion of the impeller contains a hub with an exhaust vent. In the alternative, a duct can be positioned adjacent to the outlet stator such that air is directed into the flow from the outlet.

Abstract: An outboard motor assembly for use as external propulsion for a watercraft includes a drive assembly, a shaft assembly, and a impeller-jet assembly coupled to the shaft assembly. The impeller-jet assembly includes an inlet stator, an exit stator, a impeller, and an external housing surrounding the stators and impeller. The inlet stator contains a plurality of blades, forcing the flow of water into an optimum direction for the impeller. The exit stator also contains a plurality of blades, which are configured to direct the flow from the impeller, removing the twist and resulting in a more efficient flow of water. The exit stator is tapered to create a more efficient flow of water. The center portion of the impeller contains a hub with an exhaust vent. In the alternative, a duct can be positioned adjacent to the outlet stator such that air is directed into the flow from the outlet.

Abstract: A screen system for marine thrusters having at least one constrictor for reducing exit jet cross-sectional area to increase exit jet velocity of a thruster.

Abstract: A screen system for marine thrusters is devised having directionally streamlined screens with geometrically-shaped contoured gratings capable of imparting thrust-enhancing effects, thereby permitting high operational efficiency and the ability to operate with little or no reduction in thrust due to cavitation.

Abstract: A screen system for marine thrusters is devised having directionally streamlined screens with geometrically-shaped contoured gratings capable of imparting thrust-enhancing effects, thereby permitting high operational efficiency and the ability to operate with little or no reduction in thrust due to cavitation.

Abstract: A means of sealing a rotating shaft against high fluid pressure with low friction torques, low leakage and low wear. This accomplished by use of sealing assembly comprising a sliding and a floating seal assembly separated by a lubricant filled chamber. The sliding seal is exposed to the high pressure environment which is kept isolated from the drive means by the chamber. Thus, the high pressure environment leaks into the chamber rather than the environment of the drive means and the non-harmful lubricant leaks slowly into the drive means environment.

Abstract: A blade and method for fabrication of a blade for use on a hub for rotation in a fluid that enjoys the benefits of a skewed blade without the disadvantages. This is accomplished through the use of alternating clockwise skewed and counterclockwise skewed sections formed along the leading edge. In bidirectional applications the alternating clockwise and counterclockwise skewed sections are formed along both edges.

Abstract: A propulsion system capable of more efficiently accomplishing all that the prior art propulsion systems can accomplish and additionally providing for manuevers that had hereto been unavailable with purely stern-driven craft through the use of a first and second devices for generating propulsion mounted at the rear of the craft to be driven. The two devices for propulsion are arranged one over the other so that the centerlines are substantially aligned vertically. A movable rudder is mounted substantially vertically at the rear of the craft parallel to the centerline of and in the effluent streams of said first and second propulsion devices. A fixed fin array is also mounted at the rear of the craft in the effluent streams of said first and second propulsion devices just forward of the rudder.

Abstract: A propulsion system capable of more efficiently accomplishing all that the prior art propulsion systems can accomplish and additionally providing for maneuvers that had hereto been unavailable with purely stern-driven craft through the use of a first and second method for generating propulsion mounted at the rear of the craft to be driven. The two methods for propulsion are arranged one over the other so that the centerlines are substantially aligned vertically. A movable rudder is mounted substantially vertically at the rear of the craft parallel to the centerline of and in the effluent streams of said first and second propulsion method. A fixed fin array is also mounted at the rear of the craft in the effluent streams of said first and second propulsion method just forward of the rudder.

Abstract: A ductless wall thruster for a marine vessel has a housing with a plenum chamber therein and, at a forward end of the housing, at least one inlet opening surrounding an outlet opening. An impeller is rotatably mounted within the housing so that when the impeller is rotated, it draws water into the housing and discharges it through the outlet opening to create a thrust. Preferably, there is a plurality of equally dimensioned inlet openings defined by stationary vanes inclined in a direction opposite the normal direction of rotation of the impeller. The outlet opening is preferably defined on a forward end of a central impeller housing in which the impeller is mounted, with the impeller having a flow area therethrough which is greater than the flow are through the outlet opening.

Abstract: An exercise method which provides increased heart rates and respiration while introducing variable resistance to the exercise through a combination of muscular resistance aided by mechanical force transference. The invention uses a force transfer member to transfer the force resulting from the extension or flexion of one muscle to a force resisting the extension or flexion of another muscle.

Abstract: A generally tubular-shaped or cylindrical vehicle for operation in a fluid medium is formed with a bluff or stubby afterbody and utilizes an actuator disc type propeller of approximately one-half to three-fourths of the diameter of its housing at its rear for propulsion. The propeller, in addition to driving the vehicles, is spaced from the body such that it inducts half or more of the boundary layer flow, thereby acting to draw the flow smoothly over the after part of the vehicle with a minimum of flow separation and turbulence and drag caused thereby. Steering in pitch and yaw is provided by a plurality of fins located just forward of the bluff rear surface of the vehicle. In this location the fins are more than usually effective, hence smaller than customary, because they are exposed to a fluid velocity which is near or above free stream velocity rather than at a lower velocity which is usual in vehicles having tapered afterbodies.

Abstract: A propulsion system capable of more efficiently accomplishing all that the prior art propulsion systems can accomplish and additionally providing for manuevers that had hereto been unavailable with purely stern-driven craft through the use of a first and second apparatus for generating propulsion mounted at the rear of the craft to be driven. The two apparatusses for propulsion are arranged one over the other so that the centerlines are substantially aligned vertically. A movable rudder is mounted substantially vertically at the rear of the craft parallel to the centerline of and in the effluent streams of the first and second propulsion apparatus. A fixed fin array is also mountede at the rear of the craft in the effluent streams of said first and second propulsion apparatus just forward of the rudder.

Abstract: An exercise method and device which provides increased heart rates and respiration while introducing variable resistance to the exercise through a combination of muscular resistance aided by mechanical force transference. The invention uses a force transfer member attached to a pivot assembly and cross members adjustably attached to the force transfer member to transfer the force resulting from the extension or flexion of one muscle to a force resisting the extension or flexion of another muscle.

Abstract: A thruster for use underwater having a rotor which may be optionally rotated either clockwise or counterclockwise. The rotor includes blading, perferably radially symmetrical about the rotor radius line, and a limited discharge area such that fluid is discharged from said limited discharge in a direction substantially perpendicular to a rotor radius line passing through the approximate center of the limited discharge area.

Abstract: A self retracting screen for turbomachinery comprised of a number of interlocking wires, the wire ends being pivotally attached to the periphery of the normal inlet of the turbomachinery. Preferably, the wires are elliptical, or streamlined, in cross-section such that the major diameters of the elliptical cross-section of the wires when the screen is closed are substantially parallel to the turbomachinery inlet stream.