Abstract: An interlock mechanism for a tractor transmission having a creeper gear arrangement is disclosed wherein the operation of the tractor engine is halted whenever the creeper arrangement is left in a condition conducive to incurring unwanted creep. The interlock mechanism is in the form of an electrical circuit operably connected to the fuel shutoff valve to halt the flow of fuel to the tractor engine whenever the creeper arrangement is left in a neutral state with the clutch engaged. The interlock mechanism provides electrical power to the fuel shutoff valve under normal operating conditions. Switches associated with the operative components of the transmission control the flow of electrical current through the interlock circuit.

Abstract: An electronically-controlled fuel injection system for internal combustion engines. When the engine is in an accelerating condition, an amount of fuel supplied to the engine is increased by means of an incremental value. It is discriminated whether or not a predetermined time period has elapsed from the time the rotational speed of the engine increased above a predetermined value, or from the time gear shifting was completed, while the engine is in the accelerating condition. The incremental value is limited to a predetermined upper limit if the former exceeds the latter before the lapse of the predetermined time period, whereby sudden increase in the engine rotational speed can be prevented.

Abstract: Determination of the engagement of a lockup clutch is performed in a system for integrally controlling an automatic transmission and an engine, wherein gear stages can be automatically switched in accordance with a preset map, the lockup clutch of a torque converter is engageable during at least one gear stage, and engine torque is changed during shifting to maintain satisfactory shift characteristics. The engagement is determined not only in response to an engaging signal of the lockup clutch from the computer, but also in consideration of a time lag after the engaging signal is turned ON. Alternatively, engagement is determined by detecting the rotary speeds of the engine and the turbine of the torque converter when the engaging signal is ON. As a result, mistaken determinations of engagement of the lockup clutch are avoided.

Abstract: Shifting of a marine propulsion device transmission drivingly connecting a drive shaft to an internal combustion engine and including a rotatable member operable to shift the transmission between forward drive, reverse drive and neutral positions in response to rotation of a shift lever is assisted by an arrangement including a pin or element pivotally connected to a push-pull assembly operated by a main control and carried by the shift lever. The shift assistance arrangement includes a spring which retains the element in a normal position relative to the shift lever when shift resistance to movement of the transmission from an "in gear" to the neutral position is less than a predetermined level and permits displacement of the element relative to the shift lever from the normal position when the shift resistance is above that predetermined level. The shift assistance arrangement also includes a switch operable when actuated to selectively interrupt engine ignition.

Abstract: 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.

Abstract: In the regulation of a motor-drive unit for a motor vehicle having a heat-engine and a continuously variable ratio transmission, in a clutch-engaged phase the heat-engine fuel feed is controlled so that it is a function of the displacement of the accelerator pedal of the vehicle and of the speed of the heat-engine such that the power delivered by the engine is substantially equal to the power required for that displacement of the accelerator pedal. In addition, the transmission ratio is controlled so that the speed of the heat-engine approaches an ideal speed which depends upon the power required and is predetermined for operation of the motor-drive unit which is optimalized in accordance with a chosen criterion. Operation is thus obtained with, for example, minimum consumption or pollution while taking into account, in the transient phase, the operation desired by the driver.