A boat trim control system that includes a boat having a bull and means such as trim tabs mounted to the hull for trimming attitude of the boat as the bull is propelled through the water. The system includes facility for selectively adjusting the trim tabs to maintain a desired boat attitude under varying load and sea conditions. A sensor is mounted on the boat hull to provide an electrical sensor signal as a function of boat attitude, and is connected to electronic control circuitry responsive to the sensor signal for determining attitude of the boat bull. This electronic control circuitry further includes facility for operator setting of a desired boat attitude. The electronic control circuitry is coupled to an operator display for indicating departure of actual boat attitude indicated by the sensor from the boat attitude desired by the operator, and/or to automatic control circuitry for automatically varying trim tab orientation with respect to the boat bull so as to maintain the boat attitude desired by the operator.

Boat trim control and monitor system

A two-stroke internal combustion engine has an air passageway for introducing air into a scavenging passageway communicating a combustion/actuating chamber disposed above a piston with a crankcase and an air-fuel supply passageway for introducing an air-fuel mixture from a carburetor into the combustion/actuating chamber. On the descending stroke of the piston, an exhaust port opens before a scavenging port formed at an upper end of the scavenging passageway opens, and an air-fuel mixture-feeding port disposed at a downstream end of the air-fuel supply passageway is opened a moment after the scavenging port is opened. Thus, air is introduced into the combustion/actuating chamber prior to the introduction of the air-fuel mixture.

Two-stroke internal combustion engine

A method of steering a watercraft propulsion device mounted to a transom plate and having a steering drive unit which allows the watercraft propulsion device to rotationally move about a swivel shaft. The method can include calculating a steering parameter for the steering drive unit in accordance with the degree of operator's steering wheel displacement, and operating the steering drive unit based on the calculated control physical quantity, in which the control physical quantity can be selected from a plurality of preset control physical quantities.

Method and system for steering watercraft

A grille shutter device adapted to be arranged at a front portion of a vehicle body, the grille shutter device including a main air inlet taking air to flow the air to a specific heat exchanger arranged in the vehicle body, a shutter mechanism arranged at the main air inlet, the shutter mechanism opening and closing to control a flow rate of the air flowing from the main air inlet to the specific heat exchanger, and a bypass air inlet allowing the air to bypass the shutter mechanism to guide the air to the specific heat exchanger.

Grille shutter device

A fuel delivery system for a fuel burning engine of a vehicle and a method of operating the fuel delivery system is provided. As one example, the method includes separating a first fuel and a second fuel from a fuel vapor on-board the vehicle, said fuel vapor including at least an alcohol component and a hydrocarbon component and said first fuel including a higher concentration of the alcohol component than the fuel vapor and the second fuel; condensing the separated first fuel from a vapor phase to a liquid phase; delivering the condensed liquid phase of the first fuel to the engine; and combusting at least the condensed liquid phase of the first fuel at the engine.

On-board fuel vapor separation for multi-fuel vehicle

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.

Operation optimizing system for a marine drive unit

A system for optimizing the operating efficiency of a boat by balancing fuel consumption against cruising speed utilizes a comparison between engine speed and boat speed to effect automatic positioning of the drive unit. The measurements of boat and engine speed before and after an incremental change in vertical position or trim position are used to calculate the percent changes in boat speed and engine speed which, in turn, are used in conjunction with selected minimum and maximum incremental percentages to effect subsequent alternate control strategies. Depending upon the relative difference in the percent changes in boat and engine speeds, including adjustments based on the minimum and maximum incremental percents, the system will automatically continue incremental movement of the drive unit in the same direction, hold the drive unit in its present position, or move the drive unit an incremental amount in the opposite direction. Operating efficiency is optimized by eliminating incremental drive unit movement which results in an engine speed increase and consequent increase in fuel consumption which is disproportionate in the increase in boat speed attained.

Fuel conserving cruise system for a marine drive unit

A dual counterrotating propeller drive mechanism for a marine propulsion system incorporates a torque splitting device which consists of a differential gear means and a ratio gear means. The torque splitting device assigns a selectable fixed fraction of the engine torque to each propeller regardless of power, thrust, and speed conditions. The rear one of the two propellers adjusts its rotational speed relative to the front propeller in response to changes in the front propeller's wake and in this way maintains optimum propulsive efficiency over a wide range of operating conditions. Furthermore, precise matching of front and rear propeller parameters for a given application is no longer required.

Torque splitting drive train mechanism for a dual counterrotating propeller marine drive system

A system for optimizing the speed of a boat at a paticular throttle setting utilizes sensed speed changes to vary the boat drive unit position vertically and to vary the drive unit trim position. The measurement of boat speed before and after an incremental change in vertical position or trim is used in conjunction with a selected minimum speed change increment to effect subsequent alternate control strategies. Depending on the relative difference in before and after speeds, the system will automatically continue incremental movement of the drive unit in the same direction, hold the drive unit in its present position, or move the drive unit an incremental amount in the opposite direction to its previous position. The alternate control strategies minimize the effects of initial incremental movement in the wrong direction, eliminate excessive position hunting by the system, and minimize drive unit repositioning which has little or no practical effect on speed.

Speed optimizing positioning system for a marine drive unit

A fuel supply system for an internal combustion engine comprises first and second fuel reservoirs connected in fluid communication with each other. The first fuel reservoir is a fuel vapor separator which has a vent conduit connected in fluid communication with a second fuel reservoir. Under normal operation, fuel vapor flows from the fuel vapor separator and into the second fuel reservoir for eventual discharge to the atmosphere. Any liquid fuel caused to flow out of the vent conduit of the fuel vapor separator is contained within the second fuel reservoir and prevented from being discharged into the cavity under the cowl of an outboard motor and eventually into a body of water in which the marine system is operated.

John M. Griffiths

Papers

Operation optimizing system for a marine drive unit

Fuel conserving cruise system for a marine drive unit

Torque splitting drive train mechanism for a dual counterrotating propeller marine drive system

Speed optimizing positioning system for a marine drive unit

Marine engine with primary and secondary fuel reservoirs