Outboard Marine Corporation

Robert G Dretzka

James L Holt

Guy D Payne

The invention provides a marine propulsion device having a lower unit including a power transmission mechanism comprising a bevel gear having a first clutch element, a propeller shaft having a second clutch element and mounted for rotational movement and for axial movement between a neutral position and an engaged position with the propeller shaft clutch element in driven engagement with the first clutch element, a collar mounted on the propeller shaft for common movement therewith and for axial movement relative to the propeller shaft and into a frictional driving engagement with the bevel gear to effect rotation of the propeller shaft at a rate less than the rotational rate of the bevel gear, and a spring biasing the propeller shaft to the neutral position, the spring being overcome to afford movement of the propeller shaft to the drive position in response to propeller shaft rotation.

Lower gearcase shift mechanism for marine propulsion device

Ignition pulses derived from an engine ignition coil primary are fed to the input of an ignition interruption circuit that employs an integrated circuit timer. The state of the output terminal of the timer is governed by an RC time constant circuit and by trigger signals supplied by a trigger circuit in response to occurrence of each ignition pulse. The timer output is coupled to the gate of an SCR which when it receives gate current as a result of the timer output being in a high state becomes conductive and bypasses ignition pulses to ground to thereby lower engine rpm to a preset minimum in which case gate current is removed and at least enough ignition pulses are allowed to be unbypassed for keeping the engine running above stalling speed. The timer, in effect, compares the interval between pulses with its time constant. When the intervals are longer than the time constant period the timer output remains low and provides no gate current, but when the opposite condition exists gate current is supplied until the intervals between ignition pulses equal or exceed the time constant period.

Marine propulsion unit having ignition interruption means to assist

Disclosed herein is a marine propulsion device and apparatus and methods for assisting transmission shifting thereof. The marine propulsion device includes an internal combustion engine and a reversing transmission having a pair of bevel gears and a clutch dog movable between a neutral position out of engagement with the bevel gears and forward and reverse drive positions in full engagement with one of the bevel gears. The marine propulsion device also includes a shift assistance arrangement included in a shift mechanism for axially moving the clutch dog between the neutral and drive positions, and which includes a load sensing lost motion shift lever arrangement having a first switch which is actuated when the resistance to axially moving the clutch dog into a drive position exceeds an upper limit. The shift assistance arrangement also includes an ignition interruption circuit responsive to actuation of the first switch for selectively interrupting the ignition of the internal combustion engine to reduce the engine torque transmitted to the bevel gears to effect relative angular displacement of the clutch dog and the bevel gears to thereby assist the shift mechanism in moving the clutch dog into and out of a drive position. The ignition interruption circuit includes a control circuit having a first timer for providing a plurality of successive timed cycles, each cycle including an ignition-kill interval and an ignition-on interval, and also having a second timer for establishing an overall cycle during which the first timer is operative, subject to the first switch.

Growing community of inventors

South Milwaukee, WI, United States of America

Robert G Dretzka