Abstract: A sprue structure is specifically designed to facilitate the rapid filling of molded polystyrene patterns with molten metal. It comprises a down sprue and parallel columnar members that are connected to the down sprue. The flow of molten metal is initially downward through the first columnar member and then it reverses direction to flow upwardly through second and third columnar members so that the patterns to be cast receive molten metal as it travels upwardly through the second and third columnar members. This decreases the amount of pyrolyzation products that could otherwise flow through in-gates and into the patterns to be cast.

Abstract: A standing push/pull exercise machine includes a frame with first and second frame sections located on opposite sides of a midplane, and defining a standing exercise position therebetween. Each frame section includes a pivotal lever which is pivotal against a selected weight resistance, preferably along a movement path which converges toward the midplane with respect to the forward facing direction of an exerciser. One of the frame sections and its corresponding levers is located further rearward of the other frame section and lever, and it is adapted for movement against a weight resistance via a pushing motion, while the other lever is adapted for movement against a weight resistance via a pulling motion.

Abstract: A fuel supply system for a marine propulsion system having an electronically controlled fuel injection system eliminates the need for a vapor separator. The system pumps an excessive amount of fuel through a plumbed fuel supply loop and cools recirculated fuel to cool all the components in the plumbed fuel supply loop, i.e. a continuous duty, constant displacement fuel pump; a pressure regulator; and a water separating fuel filter. Recirculated fuel flows from the pressure regulator to the water separating fuel filter as does make-up fuel from a fuel tank. The fuel stream from the water separating fuel filter flows to the low-pressure side of the fuel pump, which pumps the fuel through the plumb fuel supply loop. A fuel injection portion of the fuel flows to the engine for combustion, while the remaining portion of the fuel is recirculated. The recirculated portion of the fuel is cooled, preferably using a water-cooled heat exchanger.

Abstract: A jet propelled watercraft has a coupling assembly to couple an engine crankshaft to a jet pump impeller shaft. The coupling assembly can accommodate substantial engine crankshaft vibrations, yet effectively isolates the jet pump impeller shaft from transverse movement. The coupling assembly includes an engine crankshaft coupling head, an intermediate coupler, an impeller shaft coupling head, and two elastomeric isolators positioned between each of the coupling heads and the intermediate coupler. The intermediate coupler is supported exclusively by the elastomeric isolators, and is allowed to tilt transverse to the rotational axis of the intermediate coupler to accommodate engine crankshaft displacement. The coupling assembly is practical for personal watercraft because, although elastomeric isolators wear or shred quickly in the presence of transverse misalignment, elastomeric isolators provide significant durability in the presence of a reasonable amount of angular displacement.

Abstract: A personal watercraft jet propulsion system has a hull design and an intake housing to optimize the structural integrity of the hull, and facilitate efficient installation of the jet propulsion system without sacrificing proper alignment of the components of the jet propulsion system. The watercraft hull includes a recess defined by an inclined bulkhead spanning between two substantially vertical sidewalls. The inclined bulkhead contains an opening between the engine compartment within the hull and the components of the jet propulsion system. The intake housing mounts to the inclined bulkhead to cover the opening. The intake housing has coplanar mounting surfaces surrounding the opening in the bulkhead. Proper alignment of the pump components requires only that the intake housing be mounted properly to the inclined bulkhead.

Abstract: A jet propulsion system for a personal watercraft provides a converging stator that can be manufactured using die-cast manufacturing techniques. The stator preferably has a stator housing having a substantially cylindrical inner surface, a stator hub, and seven equally spaced stator vanes supporting the hub coaxially in the stator housing. The cylindrical inside surface of the stator housing does not extend rearward as far as a conventional housing for a converging stator. The coaxial hub has a converging diameter portion that is located at least in part downstream or rearward of the stator housing. Rearward of the stator housing, the stator vanes extend from the stator hub to an outer free edge. With this configuration, a converging stator can be manufactured using aluminum die-cast manufacturing techniques.

Abstract: A collapsible fuel tank system for use on aircraft and the like includes a plurality of nestable shell sections which, when assembled in proper edgewise orientation, form a shell for the fuel tank. A nose cone and a number of shell-reinforcing bulkheads are axially spaced within the fuel tank and have a ring-and-groove construction for facilitating manual assembly of a fuel tank. A preassembled fuel management system includes an elongated flexible liner encapsulating the bulkheads and having snap connections for quick attachment to the shell interior. All of the components of a plurality of fuel tanks are housed in a single container for shipping and handling purposes.

Abstract: A floating marine propeller wrench (18) is provided for removing a marine propeller nut (16), and comprises a floating member composed of a material selected to have a specific gravity less than or equal to 1.0, to enable floatation, yet strong enough to apply torque of at least 50 lb.ft. to the nut. The floating member is composed of chemically coupled long glass fiber reinforced polypropylene, particularly ten percent glass by weight, one percent foaming agent by weight, and the balance polypropylene. The material is also selected to provide a user detectable slight deflection (70) of a handle portion (24) when approximately 50 lb.ft. is applied to the nut by a socket portion (22), to provide a combined floating marine propeller wrench and torque meter.

Abstract: A bulk RF absorber and a method for constructing same. The absorber is composed of multiple sheets of a reticulated dielectric material, each sheet being coated with at least one layer of radiation absorbing material to create a radiation absorption gradient across a width dimension of the sheet. The sheets are stacked with their respective absorption gradients aligned to form the bulk absorber. In one embodiment, the coated sheets are constructed by lengthwise feeding the dielectric material through a sputtering region and interposing a partial mask between the sputtering material and the face of the dielectric material. The contour of an edge of the mask, the sputtering rate and feed rate determine the resulting absorption gradient of the coated dielectric material. In another embodiment, a dipping process is used to coat each sheet with radiation absorption material.

Abstract: An exhaust relief system for an outboard motor includes an exhaust chamber into which exhaust is discharged from the engine. A first passage in communication with the exhaust chamber provides contraction of the exhaust as the exhaust passes rearwardly, from which the exhaust is discharged into an expansion chamber which substantially surrounds the exhaust chamber. From the expansion chamber, the exhaust is routed through and contracted into a second passage in communication with the expansion chamber, after which it is discharged to atmosphere. The tortuous path provided by the exhaust relief system of the invention, along with the repeated expansion and contraction of the exhaust as it flows to atmosphere, provides a muffling effect at idle operation.

Abstract: A marine propulsion system has a conduit (14) connected between a water cooled internal combustion engine (4) and a remote fuel tank (12). The conduit has a first passage (16) supplying fuel from the tank to the engine, a second passage (18) supplying cooling water from the engine towards the tank, and a third passage (22) returning water from the second passage back to the engine. The passages are in heat transfer relation to the conduit.

Abstract: An annular permanent magnet rotor (8) is mounted around and fixed to a crankshaft (4) of an internal combustion engine (2) and has a plurality of circumferentially spaced magnetic poles (14) of sequentially alternating north-south polarity type, and a pole (18) reversed out of the alternating sequence. A first fixed stator (24) is provided by an annular ring concentric to the rotor (8) and has a plurality of poles (26) for magnetic flux coupling with the permanent magnet rotor poles (14). A second fixed stator (48) is axially spaced from the first stator (24) and has a pair of poles (50, 52) for magnetic flux coupling with the rotor (8). A first sensor coil (40) around the first stator (24) outputs a timing angle signal. Processing circuitry produces a series of digital pulses having ANGLE-defining edges occurring at fixed angular increments of crankshaft rotation.

Abstract: A hypereutectic aluminum-silicon casting alloy having particular use in casting cylinder blocks for marine engines. The alloy is composed by weight of 16% to 19% of silicon, 0.4 to 0.7% magnesium, up to 0.37% copper and the balance aluminum. With the stated silicon content the alloy has good fluidity and the precipitated silicon crystals provide excellent wear resistance. In addition, the alloy has a narrow solidification range of less than 150.degree. F., thereby providing the alloy with excellent castability. The copper content is maintained at a minimum so that the alloy has improved resistance to salt water corrosion.

Abstract: An integral hydraulic valve and cylinder assembly for power steering a marine drive. The assembly is operatively connected between the propulsion unit and the steering wheel of a boat and includes a common valve body for housing both the cylinder and the valve. A valve spool located within a spool-receiving bore formed in the valve body is axially slidable therein in response to movement of the steering wheel between neutral and operational positions for selectively establishing fluid communication of an inlet port with outlet ports and work passages in the valve body leading to the cylinder. A core wire is connected to the steering arm of the propulsion unit and is axially slidable within an internal bore in the valve body. In response to valve spool movement, hydraulic assistance is properly directed to aid in steering the boat.

Abstract: In a two cycle internal combustion engine (2) wherein heavy fuel ends accumulate in lower portions of the crankcase (8), recirculation means (36, 38) are provided for variably recirculating the heavy fuel ends back into the crankcase only at higher engine speeds for subsequent combustion. The heavy fuel ends are collected in a reservoir (36), and held therein at idle, to minimize engine smoke. The heavy fuel ends are released from the reservoir at higher engine speed for recirculation through a delivery line (40) which is selectively exposed by a throttle valve (24) to crankcase vacuum only at higher engine speed, whereby the heavy fuel ends are sucked from the reservoir through the delivery line and carburetor throat (26) into the crankcase.

Abstract: In a two cycle internal combustion engine having a water cooling system with a water valve (4) spring biased (64) to a normally closed condition and opened by water pressure in the engine block (14) to permit passage of water out of the block to a radiator or the like for increased cooling, an improvement is provided for keeping the water valve closed at idle without increased spring pressure such that the water valve remains closed at idle, notwithstanding block pressure, and thus enables the engine to warm up, and such that the water valve opens at higher engine speeds to afford proper cooling and prevent abnormally high water pressure in the block which would otherwise be caused by increased spring pressure. Engine crankcase pressure (6) is continually provided (24) to the valve to aid spring biased closing thereof.

Abstract: A marine propulsion system is provided with a valve (2) for automatically mixing fuel and oil for a two cycle crankcase compression internal combustion engine. The valve operates on a pressure differential, such as that supplied from the suction intake vacuum side of a fuel pump. Fuel is alternately and cyclicly directed by a transitioning shuttle spool valve (50) through respective transfer passages (34, 38) to opposite sides of a diaphragm (24) to drive the diaphragm in reciprocal movement such that in a first half cycle the diaphragm is driven in one direction and expels fuel from its one side, and in the second half cycle the diaphragm is driven in the other direction and expels fuel from its other side. A plunger (48) operatively couples the diaphragm to the directional shuttle spool valve through spring biased lost motion detent means (52). The directional shuttle spool valve is actuated between its alternate positions near the end of the plunger travel stroke in each direction.

Abstract: Clutch apparatus (2) for a marine drive lower gear case (4) includes a wrapped spring clutch (18) mounted to a propeller shaft (6) for engaging drive gear means (8) for driving the propeller shaft. The clutch is radially expandable to engage the drive gears along an axially extending friction face engagement surface.

Abstract: A marine drive for a boat includes a torque converter between the engine and propulsion unit. The torque converter has a slip condition in which a torque magnifying, fluid coupling is interposed between the engine and the propulsion unit. The slip of the torque converter enhances acceleration of the boat by permitting rapid increases in engine speed and power through relieving propeller loading of the engine. The torque converter has a lock-up condition in which the input and output shafts are directly and mechanically coupled together to provide highly efficient, sustained speed operation of the boat. A control operates the torque converter between the slip and lock-up conditions. This control may be obtained responsive to operating conditions in the engine or torque converter, such as engine speed, torque converter slip, throttle position, intake manifold vacuum, and engine ignition advance.