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 RFID reader system for tracking and locating RFID tags is described, along with an antenna suitable for use in this system, and an antenna configuration apparatus for use in this system. The system offers an antenna configuration that is cost-effective and easily reconfigurable, in which antennas with integral tuning components can be moved or replaced with antennas of a similar or different format. An end user is therefore able to easily reconfigure his or her platform in the field, in order to account for different products or different product orientations. Specific orientations of the reader antennae will furthermore increase system functionality by permitting multiple tag locations on the product.

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: 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 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 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: 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.

Abstract: A watercraft propulsion device having a forward and a rearward foil in nested relationship for reciprocal oscillating movement in opposite directions having a foil angle greater than 0.degree. and less than 60.degree..

Abstract: A wall thruster for surface or submarine vessels that is cavitation resistant and does not require a hull duct. The invention comprises an impeller mounted in a swirl chamber such that seawater is rotated under pressure. The water is then discharged through streamlined nozzles in a direction to minimize mixing with the flow of the water being drawn into the impeller.

Abstract: A fluid control valve which avoids wear, cavitation, and high noise level operation and yet is substantially nonclogging. The valve includes a valve nozzle means having at least one preloaded member biased so as to close the valve nozzle means below a preselected incoming fluid pressure. Incoming fluid is spun tangentially within an annular whirl chamber, and then passed through a labyrinth passageway comprising a series of inwardly spaced concentric sleevelike annuli. The concentric sleevelike annuli are so constructed that they may be inserted into a pre-existing plug valve.

Abstract: A fluid control valve and its method of use, the valve having a plurality of annular fluid control elements stacked within a housing, and resilient means for biasing the fluid control elements in a spaced apart relationship in order to provide for fluid flow between the fluid control elements, the fluid control elements forming a seat adapted to receive the resilient means and also including means for producing an interference fit about the periphery of the fluid control elements adjacent the center space within the annular stack of fluid control elements.

Abstract: Axial flow turbomachinery having an impeller with a plurality of contoured blades mounted within a diffuser throat and about a central rotatable hub. This blade shape is defined by the ratio of the blade root and tip chords to the minimum midsection blade chord, which is between about 1.25 and about 2.25. The ratio of blade pitch at the root and tip sections as compared with the blade midsection pitch is preferably between about 1.0 and about 1.4.This configuration of a preferred diffuser is described by the following relationship: ##EQU1## Where A.sub.t is the diffuser cross-sectional area at the diffuser throat, A.sub.o is the diffuser cross-sectional area at the outlet, l is the diffuser length from the diffuser throat to the diffuser outlet, x is a distance along the diffuser measured from the diffuser throat toward the diffuser outlet, A.sub.x is the diffuser cross-sectional area x distance from the diffuser throat and n is a value between about 2 and about 4.

Abstract: A fluid control valve and its method of use, the valve having a plurality of annular fluid control elements stacked within a housing, and resilient means for biasing the fluid control elements in a spaced apart relationship in order to provide for fluid flow between the fluid control elements the fluid control elements forming a seat adapted to receive the resilient means and also including means for producing an interference fit about the periphery of the fluid control elements adjacent the center space within the annular stack of fluid control elements.