Brunswick Corporation

Tru-fire Corporation

Herbert A Bankstahl

Neil A Newman

Wayne T Beck

John M Griffiths

Lyle M Forsgren

Robert B Weronke

Anthony L Debates

A caliper type bow string release includes a reversible trigger which is operable selectively in either the push fire mode or the pull fire mode. The caliper jaws of the release include automatic alignment and locking features, whereby movement of the string into a retaining notch engages the automatic locking mechanism and closes the release into a string retaining position until the release is fired by activation of the trigger. A complex cam surface is provided on the actuator for permitting incremental linear adjustment of the trigger force. In one embodiment, each jaw includes an arcuate socket in alignment with a complementary socket on the opposing jaw. A spherical member is received in the sockets. A head is secured to the spherical member and extends into the retaining notch; placement of the string against the head pivots the jaws to the closed position. In another embodiment, each jaw includes an arcuate synchronizing tab to be received in a concave arcuate recess in the complementary jaw. An automatic latching feature comprises a latch tab and complementary latch receiving seat on each jaw. The latch tab is adapted to intercept the bow string as it is introduced into the retaining notch to pivot the jaws closed.

Caliper type bow string release having push/pull trigger and automatic

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

A marine stern drive unit is mounted aft of the boat transom on a rigid lift arm in a manner allowing the drive unit to be independently trimmed or moved vertically up or down. The drive unit is pivotally attached to the aft end of the lift arm for trimming movement about a generally horizontal axis and the lift arm is pivotally attached to the boat to rotate about a second horizontal axis such that the drive unit is moved generally vertically. The boat engine is preferably mounted transversely and power transmission from the engine to the drive unit is provided by a flexible drive belt which is supported by the rigid lift arm. Separate trim and lift movement is supplied to the drive unit by individual fluid cylinders. The trim cylinder operatively interconnects the drive unit with the boat hull or the forward end of the lift arm. The lift cylinder operatively interconnects the boat hull and the lift arm at a point aft of its pivotal connection to the boat.

Stern drive lift and trim system

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 marine propulsion system includes a steerable lower gearcase portion and a drive mechanism including a chain drive for driving dual counterrotating propellers. The dual propellers are rotatably mounted to the lower steerable gearcase portion by means of inner and outer coaxially extending propeller shafts. A sprocket is mounted to each propeller shaft, and first and second chain portions extend between the propeller shaft sprockets and a pair of upper drive sprockets, preferably disposed above the water line during boat operation. Coaxially extending inner and outer drive shafts are interconnected with the engine output shaft, and are adapted for counterrotation in response to rotation thereof. The coaxial drive shafts are interconnected with the upper drive sprockets for driving such sprockets in opposite rotational directions, thereby resulting in movement of the first and second chain portions in opposite directions. The longitudinal axis of the inner and outer drive shafts defines the steering axis about which the lower steerable gearcase portion is pivotable.

Chain driven marine propulsion system with steerable gearcase and dual

A V-type four-stroke cycle internal combustion engine is provided with an exhaust manifold and an air intake manifold disposed in the valley of the V-engine, and arranged one above the other. The exhaust from the cylinders passes through exhaust passages formed in the cylinder heads which discharge exhaust into the valley of the V-engine for collection in a central exhaust cavity provided in the exhaust manifold. A single exhaust discharge outlet is in communication with the central exhaust cavity for discharging exhaust therefrom. The air intake manifold includes a series of air intake passages which supply air to the cylinders from within the valley of the V-engine. A series of cylinder head intake passages are provided with openings facing the valley of the V-engine for receiving air therefrom. The exhaust manifold is preferably water jacketed for cooling exhaust prior to its discharge from the engine, and the exhaust passages provided in the cylinder heads are also water jacketed. In a carbureted system, the water warmed by the exhaust acts to pre-heat air passing through the cylinder head air passages prior to its entry into the cylinders, which improves low-speed performance of the engine. The push rods are either disposed in a conventional arrangement wherein the cam shaft is located in the apex of the V-shape formed by the push rods, or may be disposed in an overhead arrangement when an overhead camshaft configuration is employed.

Four-stroke V-engine with central exhaust and intake manifolds

A marine drive (2) includes a lower drive unit (4) having a strut portion (6) and a torpedo portion (10) which are blended along a blended portion (30) such that all horizontal cross-sections through the blended portion and the strut portion have outer profiles defining smooth continuous non-concave surface elements continuously curved convex along the entire front to back length thereof, and such that all vertical cross-sections through the strut portion, blended portion and torpedo portion have outer profiles defining a central zone (62) of concave outer surface elements wherein the degree of concave curvature continually increases front to back.

Marine drive unit with reduced drag

A chain drive marine propulsion system employs dual counterrotating propellers. The propellers are mounted to concentric propeller shafts disposed in the lower end of a depending gearcase. The concentric propeller shafts are each provided with a lower sprocket engaging a chain. A counterrotation mechanism is provided for driving the chains in opposite directions, thereby resulting in counterrotation of the propellers. Various embodiments for driving the chains in opposite directions are disclosed.

Chain drive marine propulsion system with dual counterrotating propellers

A marine propulsion system is provided with dual counterrotating propellers, and a shaft and gear arrangement for driving the propellers. In a preferred embodiment, the marine propulsion system includes a depending gearcase having a steerable lower portion which is pivotable about a steering axis relative to an upper gearcase portion. A pair of coaxial drive shafts extend longitudinally through the gearcase, and are interconnected with the engine output shaft so as to rotate in opposite directions in response to rotation of the output shaft. The counterrotating propellers are preferably mounted to a pair of coaxial propeller shafts, and appropriate gearing is disposed between the coaxial propeller shafts and the coaxial drive shafts to drive the propeller shafts, and thereby the propellers, in opposite rotational directions. In a preferred embodiment, the gearing includes counterrotating gears fixed to the counterrotating drive shaft so as to provide cancelling gear torque loads about the steering axis. The counterrotating propellers likewise provide cancelling propeller torque loads to further accommodate steering of the steerable gearcase portion.

Gear driven marine propulsion system with steerable gearcase and dual

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

In a stern drive for watercraft, of the type using a gimbal ring to support the external propulsion unit, the gimbal ring is provided with an upper vertical square bore, a slot across the bore, and clamping bolts to provide full engagement with the square sides of a steering swivel shaft.

Stern drive gimbal arrangement

The male cone member of a cone clutch mechanism has two springs, each encircling cam faces on the male cone member and bearing against the forward and reverse clutch gears, respectively, to bias the cone member away from its center or neutral position toward either the forward or reverse clutch gear. An eccentric roller on the shift actuator shaft engages with a circumferential groove in the male cone member to provide a vibrating force against the member for shifting. The shift means uses a cam and bell crank mechanism to convert axial movement of the shift controller to rotary movement of the actuator shaft.

Shifter linkage for a cone clutch

A cone clutch mechanism has its forward and reverse clutch gears supported by bearings mounted on the housing, with a main shaft supported by bearings mounted on the housing in the same planes as the forward and reverse gear bearings. The male cone member is biased by two springs, each encircling cam faces on the member and bearing against the forward and reverse clutch gears, respectively, to bias the cone member away from its center or neutral position.

Cone clutch

A flexible bellows assembly covers the universal drive coupling connecting between a marine stern drive unit and the inboard engine. The flexible bellows includes a rectangular bead at the periphery of one end and is tubular shaped at the other end. The tubular shaped end is sealably clamped over a projecting portion of the transom bracket and the rectangular bead end is sealably contained within a clamping chamber formed by complimentary portions of the stern drive unit housing and the bell housing portion of the pivot mounting assembly.

Flexible bellows end connection in a marine stern drive

A marine stern drive includes an inboard engine having an exhaust passageway connected to an outboard drive unit having an exhaust passageway. A transom bracket assembly positioned between the engine and the drive unit permits vertical pivoting of the drive unit for steering and horizontal pivoting of the drive unit for steering and horizontal pivoting of the drive unit for trimming. The improvement includes a first exhaust pipe connected to the inboard engine and a second exhaust pipe connecting to the drive unit. The first exhaust pipe extends outward through the transom of the boat and has an open end position centered on and adjacent the vertical pivot axis and below the vertical pivot axis. The second exhaust pipe extends towards and ends in alignment with the end position of the first exhaust pipe to form an interface which includes an opening between the pipe ends.

Growing community of inventors

Fond du Lac, WI, United States of America

Herbert A Bankstahl