Abstract: A plastic oil pan (16) for an internal combustion engine (14) has an upper lip (18) for mating with the engine in sealing relation, sidewalls (21-24) depending downwardly below the lip, a bottom (26) extending between the sidewalls below the lip to provide a closed-bottom receptacle for holding engine oil, and a plurality of reinforcing walls (28, 30, 36, 38, 40) integrally formed along the sidewalls and increasing the mechanical strength of same to enable the plastic oil pan to support the engine when the latter rests on the oil pan during installation or repair procedures. A conduit (54) extends through the oil pan and passes engine coolant therethrough to cool the engine oil. Particular oil pan and conduit structure is disclosed.

Abstract: A pulse balancing system is provided for a multicylinder two-stroke cycle internal combustion engine in which each cylinder is provided with its own mechanism for supplying an air-fuel mixture thereto. The vacuum pulse balancing system of the invention comprises a plurality of passages interconnecting each cylinder with one of the air-fuel mixture supply devices associated with one of the other cylinders, and one-way check valves provided in the passages. With the vacuum pulse balancing system of the invention, a vacuum pulse created by the piston in one of the cylinders is transferred not only to the air-fuel mixture supply device associated therewith, but also to the air-fuel mixture supply device associated with one of the other cylinders. This alleviates back pressure which may otherwise be caused in the air-fuel mixture supply device associated with the other cylinder due to the on-again off-again suction of air-fuel mixture therefrom to its associated cylinder.

Abstract: A marine propulsion device is provided wherein a flexible bellows (33) surrounding the universal joint (20) disposed between a marine engine (5) and a stern drive unit (2) is mounted to rotate with the universal joint itself. The universal joint is disposed within a chamber (61) delineated by the bellows itself and by end caps (34,43) mounted to the universal joint shafts (25,30). Supports (53,56) for the universal joint bearings (54) are constructed to permit free flow of fluid around the bearings. A quantity of lubricating oil is supplied to the chamber and at least partially fills the chamber when the latter is at rest. Upon driving rotation of the device, the bellows and universal joint and lubricating oil all rotate together. The resultant centrifugal force causes the oil to flow radially outwardly through the bearing supports to lubricate the bearings, with the oil forming a rotating mass engaging the inner bellows face.

Abstract: A corrosion resistant coolant pump for placement in the cooling system of a marine drive includes a corrosion resistant member mounted to and rotatable with a drive shaft interconnected with and rotatable in response to the engine crankshaft. The corrosion resistant member is preferably a cup adapted for receiving and enclosing an end of the drive shaft, with a portion of the cup extending into a cavity formed in the coolant pump housing. The cavity is in communication with marine drive cooling system. An impeller is connected to the cup and housed within the cavity for pumping coolant through the system. The cup is interconnected with the drive shaft so as to be rotatable in response thereto, thereby driving the impeller in response to rotation of the drive shaft. A sealing mechanism is provided about the cup for sealing the cavity and preventing contact of coolant with the drive shaft.

Abstract: A fuel line cooler (34) is provided for a marine propulsion system (2) having a water cooled internal combustion engine (4) in a heat retentive compartment (5). The fuel line cooler (34) has an inlet (36) in communication with the source (14, 12) of cooling water for the engine (4), and has an outlet (38) for discharging water. The fuel line cooler (34) is cooled by sea water during running of the engine (4). Upon turn off of the engine (4), the cooled water in the fuel line cooler (34) is in heat transfer relation with the fuel and prevents vaporization and or spewing of the fuel.

Abstract: The manual operating cord for a deck-mounted electric trolling motor includes a handle which is demountably attachable to an arm of the pivotal motor support apparatus when the motor is in the operative or stowed position. The demountable handle assures that the operating cord will always be readily accesible to the operator in the boat to either raise the motor from its operative position or lower it thereto from its stowed position on the deck. The handle is demountably secured to one of the pivot arms of the motor support apparatus by frictional engagement between the legs of an elongated U-shaped slot in the handle and the lateral faces of the pivot arm.

Abstract: A marine stern drive unit (1) includes an assemblage of a propeller-carrying drive shaft housing (10), a bell housing (9) and gimbal housing (8). Mating flow-through passages (21, 23) are disposed in the drive shaft housing and bell housing, and a dual control valve system (30, 31) joins the passages at their juncture. The valve system is arranged to be open when the two housings are assembled, but closes automatically when the housings are disassembled to retain lubricant in the separate housing assembles when the latter are separated for servicing. The valve system includes a valve (31) in one of the passages (23) which is constructed to be snapped together and to be held firmly within the passage, but manually and quickly releasable therefrom when desired. The fluid passage (23, 26) in the bell housing communicates to the gimbal housing which has a sealed fitting (60) and a lubricant carrying portion (65) passing through the usual gimbal mounting hole (14) of the boat transom (2).

Abstract: A system for optimizing the operation of a marine drive of the type whose position may be varied with respect to the boat by the operation of separate lift and trim/tilt means includes an automatic control system which stores preselected drive unit positions for various operating modes and is operative to return the drive unit to any pre-established position by pressing a selected operating mode positioning button. The various operating modes may include cruising, acceleration, trolling and trailering position, any of which may be selectively modified to accomodate changes in both operating or environmental conditions. This system may incorporate other optimization routines and/or automatic engine protection systems to provide virtually complete push button operation for complex marine drive unit positioning mechanisms.

Abstract: An improved exhaust port throttling mechanism for a two-stroke engine. The engine includes a plurality of in-line cylinders each having an exhaust passage disposed to be closed during reciprocating movement of the piston. The exhaust passages communicate with a common exhaust chamber and a tubular valve member is mounted for rotation within the exhaust chamber. The valve member includes a plurality of apertures, each adapted to register with one of the exhaust passages. When used with a V-6 engine having two banks of in-line cylinders, a shaft is connected to each valve member and the corresponding ends of the shafts are interconnected by meshing gear segments.

Abstract: A fuel line cooler (34) is provided for a marine propulsion system (2) having a water cooled internal combustion engine (4) in a heat retentive compartment (5). The fuel line cooler (34) has an inlet (36) in communication with the source (14, 12) of cooling water for the engine (4), and has an outlet (38) for discharging water. The fuel line cooler (34) is cooled by sea water during running of the engine (4). Upon turn off of the engine (4), the cooled water in the fuel line cooler (34) is in heat transfer relation with the fuel and prevents vaporization and or spewing of the fuel.

Abstract: A stern drive for a marine vessel is provided with a series of internal passageways that route the hydraulic fluid to the trim cylinders so that external hydraulic hoses can be eliminated.

Abstract: In a two stroke internal combustion engine (2) having a pair of spark plugs (28, 30) for each cylinder (6), a particular height and spacing ratio of the spark gaps (32,34) have been found to produce misfire-free running during idle. The ratio h/H should be less than 0.5, where h is the height of the spark gaps (32, 34) above the squish surface (20) or the top (60) of the cylinder sidewalls, and H is the height of the top (36) of the combustion chamber above such surface. The ratio d/D should be in the range of about 0.25 to 0.35, where d is the distance between the spark gaps (32, 34), and D is the inner diameter of the cylinder (6).

Abstract: A preassembled throttle cable and pulley assembly includes a pair of pulleys contained within pulley housings. A pair of throttle cables are strung around the pulleys in a predetermined manner and the cable ends are contained within the pulley housings. The pulleys are keyed so as to insure their attachment to a tiller and throttle linkage in a proper configuration.

Abstract: A sealed fuse holder (10) adapted to receive a fuse (14) having a fuse body (16) with a pair of spaced parallel male blade terminals (18, 20) extending therefrom, includes a resilient rubber electrically insulating receptacle (12) having a front face (26) with an opening (28) defining a cavity (30) extending rearwardly therefrom and having a back wall (32) spaced rearwardly from the front face and having side walls (28, 30) extending from the front face at the opening rearwardly to the back wall. A pair of spaced electrically conducting female terminal-receiving clips (22, 24) extend rearwardly from the back wall and receive respective blade terminals inserted rearwardly thereinto. A first seal (38) provides sealing from the front, and a second seal (12) including the back wall (32) provides sealing from the rear. The combination seals the electrical contact surfaces and the fusible link, and provides moisture-proof and explosion-proof sealing in marine application.

Abstract: A V-type four-stroke cycle internal combustion engine is provided with an exhaust manifold disposed in the valley of the V-shaped engine. The exhaust from the cylinders passes through the cylinder heads to an exhaust collection cavity formed in the exhaust manifold. The manifold is provided with water jackets above and below the exhaust collecting cavity to cool exhaust collected therein. An air intake manifold is also provided in the valley of the V-shaped engine, located above and adjacent the exhaust manifold. The air intake manifold has a central cavity, with induction tubes extending from the manifold to outside the valley of the V-engine for introducing air to the cylinders therefrom. The induction tubes provide induction tuning to the engine, to increase the torque provided by the engine. The arrangement of the engine components provides compact packaging for a V-type engine.

Abstract: A marine propeller (4) combines decreasing overall pitch from hub (6) to blade tip (20) and increasing progressiveness of pitch with increasing radii from hub to tip, and provides uniform loading from hub to tip. The balde has a maximum transverse dimension (36, 46, 48) between the high pressure surface (16) of the blade and a straight line chord (34, 34a, 34b) between the leading edge (22) and the trailing edge (24) of the blade. The ratio of this maximum transverse dimension to the length of the chord is ever increasing from hub to tip. A parabolic blade rake along the maximum radial dimension line (50) of the blade is provided in combination.

Abstract: A graphic image represented by a two-level pel-to-pel definition is compressed by one-dimensional redundancy reduction coding using an entropy preserving algorithm which allows for real time reduction of the pel-to-pel data without any loss in image resolution. The compressed data is concatenated for transmission and then separated and decoded back to a pel-to-pel format for defining a facsimile image.

Abstract: An apparatus is provided for generating a random (mezzotint) screen for producing halftone copies of continuous tone documents. The random screen comprises a matrix of random numbers representing a sequence of digital reference values with respect to which video (scan) signals are compared for producing halftone picture elements (pels). The apparatus comprises a first and a second random number generator, the first being disposed for providing an initial or starting state for the second, in response to applied clock pulses. Using the supplied starting state, the second random number generator produces the random screen reference values in response to applied clock signals. The random screen reference values produced by the apparatus permits minimum halftone dot size (i.e., the size of the dot used in producing halftone images) to be varied, and halftone patterns to be selectively repeated or not repeated.

Abstract: A tandem dual-head lithographic duplicator is equipped for operation in alternative modes, i.e., either for duplexing by printing on opposite faces of the copy sheets in sequence, or for simplexing. In the simplexing mode the printing of the copy sheets is carried out on one head simultaneously with the cleanup and preparation operations on the other head, with a sequence of printing jobs being performed alternately on one printing head and then on the other while, in each case, the non-printing head is being prepared. Accordingly, substantially continuous simplexing operation can be achieved except in the case of very short printing runs.

Abstract: A diazo microfilm which is resistant to fading upon exposure to strong light for extended periods of time is provided. The fade-resistant diazo microfilm is produced by saponifying a cellulose alkanoate film to an extent defined by certain infrared absorption parameters.