Abstract: A roller assembly facilitates travel of a watercraft hull on a floating dock having a longitudinal, keel-receiving valley with a pair of flanking ridges supporting opposite sides of the hull during docking and launching of the craft. Pockets in the ridges contain wheels mounted on circumferential planes parallel to the ridges for rotation on axles seated in the pockets. The upper portions of the wheels protrude above the crests of the ridges and the axle end bearing portions cooperate with the seats in the pockets to list the circumferential planes toward the valley and approximately perpendicular to the hull sides. For optimal performance, two or more roller assemblies can be arranged in-line and spaced apart longitudinally in each of the ridges. A brake stops the docking motion of the watercraft onto the dock. Multiple docks can be serially connected without use of special tools or underwater assembly steps.

Abstract: In a lift for mooring a boat stern-on, a pair of horizontally spaced guide members is fixed to the sea wall. A frame is fixed to a pair of substantially parallel hydro-pneumatic buoyancy tanks to provide a flotation platform for supporting the hull of the boat. The stern end of each of the tanks is connected to the guide members. The guide members limit movement of the platform away from the sea wall and along the sea wall but permit vertical reciprocation of the stern ends of the lift tanks in unison and restrict the lift from listing during operation.

Abstract: A plastic rotationally molded polyethylene buoyancy tank for boat lifts allows connection of steel to lengthwise grooves molded into each side of the buoyancy tank. Preferably, a plastic bulkhead is formed within the tank during its molding process. A segment of framing steel is bracketed between a pair of inwardly tapered compressible opposed grips. The compressible grips each have outwardly tapered slots with mating tapered rigid inserts. With the inserts partially seated on the grips, the grips are slipped lengthwise or pressed laterally into their respective grooves. Bolts extending through the grips into threaded holes in the inserts are tightened to pull the grips over their tapered inserts. This spreads and compresses the grips in their respective grooves, locking the brackets and connecting steel in place on top of the tanks.

Abstract: A plastic rotationally molded polyethylene buoyancy tank for boat lifts allows connection of steel to lengthwise grooves molded into each side of the buoyancy tank. Preferably, a plastic bulkhead is formed within the tank during its molding process. A segment of framing steel is bracketed between a pair of inwardly tapered compressible opposed grips. The compressible grips each have outwardly tapered slots with mating tapered rigid inserts. With the inserts partially seated on the grips, the grips are slipped lengthwise or pressed laterally into their respective grooves. Bolts extending through the grips into threaded holes in the inserts are tightened to pull the grips over their tapered inserts. This spreads and compresses the grips in their respective grooves, locking the brackets and connecting steel in place on top of the tanks.

Abstract: In a lift for mooring a boat stern-on, a pair of horizontally spaced guide members is fixed to the sea wall. A frame is fixed to a pair of substantially parallel hydro-pneumatic buoyancy tanks to provide a flotation platform for supporting the hull of the boat. The stern end of each of the tanks is connected to the guide members. The guide members limit movement of the platform away from the sea wall and along the sea wall but permit vertical reciprocation of the stern ends of the lift tanks in unison and restrict the lift from listing during operation.

Abstract: In a lift for mooring a boat stern-on, a pair of horizontally spaced guide members is fixed to the sea wall. A frame is fixed to a pair of substantially parallel hydro-pneumatic buoyancy tanks to provide a flotation platform for supporting the hull of the boat. The stern end of each of the tanks is connected to the guide members. The guide members limit movement of the platform away from the sea wall and along the sea wall but permit vertical reciprocation of the stern ends of the lift tanks in unison and restrict the lift from listing during operation.

Abstract: A plastic rotationally molded polyethylene buoyancy tank for boat lifts allows connection of steel to lengthwise grooves molded into each side of the buoyancy tank. Preferably, a plastic bulkhead is formed within the tank during its molding process. A segment of framing steel is bracketed between a pair of inwardly tapered compressible opposed grips. The compressible grips each have outwardly tapered slots with mating tapered rigid inserts. With the inserts partially seated on the grips, the grips are slipped lengthwise or pressed laterally into their respective grooves. Bolts extending through the grips into threaded holes in the inserts are tightened to pull the grips over their tapered inserts. This spreads and compresses the grips in their respective grooves, locking the brackets and connecting steel in place on top of the tanks.

Abstract: In a lift for mooring a boat stern-on, a pair of horizontally spaced guide members is fixed to the sea wall. A frame is fixed to a pair of substantially parallel hydro-pneumatic buoyancy tanks to provide a flotation platform for supporting the hull of the boat. The stern end of each of the tanks is connected to the guide members. The guide members limit movement of the platform away from the sea wall and along the sea wall but permit vertical reciprocation of the stern ends of the lift tanks in unison and restrict the lift from listing during operation.

Abstract: An antenna system adapted to provide antenna beams having various characteristics, such as various beam widths and/or different orientations, is disclosed. In a preferred embodiment, the antenna system is adapted to provide forward link signals in wide antenna beams while providing reverse link signals in narrow antenna beams. In the preferred embodiment multiple forward link wide beams are provided to allow uniform radiation of forward link signals throughout a desired area, such as a sector of a cell, while multiple non-overlapping narrow antenna beams are provided in the reverse link. In the preferred embodiment passive or parasitic antenna elements are utilized in the antenna array to provide symmetric current distribution in the antenna array to provide multiple beams having uniform characteristics.

Abstract: Systems and methods for providing antenna beams having reduced grating and side lobes when steered off of the antenna broadside are disclosed. According to the present invention an arrangement of antenna elements suitable for use in generating antenna beams steered at greater angles off of the antenna broadside is utilized with a beam feed network consistent with the antenna beams being steered at the greater angles and reduced antenna element spacing to provide the reduced grating and side lobes. A preferred embodiment utilizes a 2n+1 Butler matrix coupled to 2n+1 antenna columns spaced according to the present invention to provide 2n antenna beams.

Abstract: A system and method are disclosed for avoiding nulls in a composite radiation pattern synthesized from a plurality of antenna beams. The disclosed invention teaches the use of delays in the signal paths associated with ones of the antenna beams utilized to synthesize the desired radiation pattern in order to avoid destructive combining of the signals. In a preferred embodiment delays are introduced in each antenna beam signal having a common attribute such as a common phase center. Accordingly, a minimum number of phase differential boundaries are introduced in order that certain communications, such as CDMA, are not adversely affected.

Abstract: A buoyant walkway module for a boatlift is formed from a plurality of pneumatically discrete elongated compartments. Each of the compartments has a substantially flat upper horizontal exterior surface and complementary exterior end surfaces. With the end of one such module in abutment with the complementary end of another such module, the upper horizontal surfaces lie in the same plane so as to provide a suitable walkway for the boatman. Preferably, the end surfaces are perpendicular to the horizontal surface so as to provide maximum stability in the walkway.With the modules positioned in end-to-end relationship, they are coupled together by a flat plate disposed across the upper exterior surface of their junction and by a pair of straps extending longitudinally across the lower exterior surface at their junction.

Abstract: Systems and methods are disclosed for providing calibration of the phase relationships of signals simulcast from a transmission system. In a preferred embodiment, a calibration signal is introduced into the transmission system and provided to various antenna elements. Samples of the calibration signal are taken at a point very near the antenna elements so as to sample phase shifts introduced by the transmission system. The signals of sets of the antenna elements are combined after sampling for transmission down the antenna mast to the active circuitry of the present invention. Accordingly, the present invention operates to selectively energize antenna elements of the sets so as to provide a single calibration signal down the combined signal path. Through reference to sampled signals one at a time, the present invention determines a necessary phase adjustment to result in the desired phase relationship of the signals at the antenna elements.

Abstract: An omni directional coverage multibeam antenna relief on a ground surface having simple conical shapes to provide beam steering is disclosed. One advantage of such a system is that the projected area is always constant and broadside to the intended direction resulting in limited scan loss effects. In the case of a cylinder as the conical shape, z-axis symmetry provides a constant antenna aperture projection in any azimuthal direction. Using this geometry, high level, side lobes are reduced considerably because of the natural aperture tapering from dispersion effects. Coverage area and power can be controlled by changing the ground surface angle and by selectively activating different antenna beam positions around the circumference of the ground surface, and by selectively changing the phase relationship between a given set of antenna beams. Likewise, beam down-tilt may be electrically realized by providing a phase differentiated signal to different antenna sections associated with an antenna beam.

Abstract: An omni directional coverage multibeam antenna composed of facets, or antenna modules, that make up a regular polygon of n sides inscribed in a circle of radius r which defines an adjustable composite conical surface. The disclosed antenna modules are independent antenna arrays creating an independent beam. One advantage of such a system is that the radiated wave front associated with such antenna modules is always substantially broadside to the array resulting in limited scan loss effects. Furthermore, the independence of the disclosed antenna modules is important as it allows each module's beam to be either electrically or mechanically steered to affect elevation or azimuthal beam control. Additionally, by employing trapezoidal shaped antenna modules, a minimum radome diameter is achieved that covers this antenna system.

Abstract: A system and method for providing distributed amplification of a plurality of input signals is disclosed. The preferred embodiment of the disclosed invention utilizes two substantially different matrixes to dissect an input signal for amplification and subsequent recombination. The unique matrixes disclosed provide for the distributed amplification of any even number of input signals, therefore reducing the number of linear power amplifiers required where a number of input signals other than a power of two are used.

Abstract: A buoyant walkway module for a boatlift is formed from a plurality of pneumatically discrete elongated compartments. Each of the compartments has a substantially flat upper horizontal exterior surface and complementary exterior end surfaces. With the end of one such module in abutment with the complementary end of another such module, the upper horizontal surfaces lie in the same plane so as to provide a suitable walkway for the boatman. Preferably, the end surfaces are perpendicular to the horizontal surface so as to provide maximum stability in the walkway.With the modules positioned in end-to-end relationship, they are coupled together by a flat plate disposed across the upper exterior surface of their junction and by a pair of straps extending longitudinally across the lower exterior surface at their junction.

Abstract: A multiple beam antenna array utilizing strategically placed parasitic elements to control side lobe levels is disclosed. Two specific arrangements of such parasitic elements are taught. A first preferred arrangement of parasitic elements provides for their placement between a ground plane and a plane of active antenna elements. An alternative preferred arrangement of parasitic elements provides for their placement both between a ground plane and a plane of active antenna elements, as well as in front of the active antenna elements. Both such embodiments provide improved side lobe control over a similar antenna system without parasitic elements. Moreover, the characteristics of the main lobe are improved by both embodiments.

Abstract: A lift for docking a personal watercraft from a body of water has a shell with a cradle for supporting the watercraft and an open end for horizontally receiving the watercraft. A buoyant filler within the shell floats it with its open end approximately aligned with the water surface. A replaceable skid plate substantially centered on the open end of the shell engages the tapered bow portion of the watercraft during the docking process and guides the watercraft into substantially a centered position on the shell and raises the watercraft upwardly and drives the shell downwardly as the watercraft is horizontally transferred onto the shell from the body of water. The shell has two pairs of posts, one pair extending forwardly from the front and one pair rearwardly from the back, one proximate each of the sides of the shell. Each post has a flange about its free end.