Abstract: A method for operating an internal combustion engine having multiple cylinders. A warm-up operation is carried out after the internal combustion engine has been started, during which a speed of the internal combustion engine is limited to a limit value. The limit value is selected during the warm-up operation at least temporarily as a function of a starting temperature of the internal combustion engine.

Abstract: A vehicle control device includes: a storage device that stores relation-defining data that is data for defining a relation between a state of a vehicle and an action variable; and an executing device configured to acquire the state, operate a drivetrain device based on a value of the action variable, derive a reward such that the reward is larger when the state of the drivetrain device based on the acquired state satisfies a predetermined criterion, perform an updating of the relation-defining data using an updating map, and restrict the updating of the relation-defining data such that an updating amount of the relation-defining data is smaller when the drivetrain device is subject to a predetermined restriction.

Abstract: A life-saving device, including: a buoyancy bag including a cavity; a wearable member including a housing; a controller including a single-chip microcomputer, a battery, a flip-flop, and an integrated circuit board; a gas generator including an input electrode terminal and a gas outlet. The single-chip microcomputer includes a plurality of pins and is disposed on the integrated circuit board; the battery, the flip-flop, and the input electrode terminal of the gas generator are respectively connected to the plurality of pins through the integrated circuit board; the housing includes a first chamber, and the battery, the single-chip microcomputer, and the integrated circuit board are disposed in the first chamber; the cavity of the buoyancy bag communicates with the gas outlet; and the buoyancy bag is deflated when in nonuse for convenience of storage, and inflated with gas produced by the gas generator to expand in an emergency.

Abstract: When control to maintain a constant engine rotation number is executed, the electronic control unit constantly monitors an error of detected throttle position data with respect to a desired throttle control value, executes a first stage of a failure judgment method to judge that a failure of a throttle control system has occurred in a case where an absolute value of the error exceeds a predetermined threshold value continuously for a predetermined time or longer, and executes a second stage of the failure judgment method to judge that a serious failure has occurred in the system in a case where a detected engine rotation number exceeds a predetermined rotation number continuously for a predetermined time or longer, to perform predetermined operations in accordance with the judgment results.

Abstract: A diaphragm carburettor comprises a diaphragm dosager (2) provided with a diaphragm (3) that separates a first chamber at constant pressure (4) from a second fuel dosaging chamber (5) intercepted by a valve controlled by the diaphragm, said valve being operatively connected with said diaphragm (3), the aforementioned carburettor also foreseeing an electromagnetic actuator (1) associated with said diaphragm (3) to control the opening and closing of said valve, where said actuator (1) also comprises at least one mobile coil (6) directly fixed to the diaphragm, and a fixed magnetic field generator (7) suitable for guiding said coil (6).

Abstract: An throttle valve is controlled by using an electric actuator. A cover for covering one end side of the throttle valve shaft is attached to a side wall of a throttle body. a throttle position sensor unit and an electronic control module for controlling the throttle valve is attached to an inner face of the cover. The throttle position sensor and the electronic control module are contiguous to each other and connected at a position contiguous thereto. The cover is provided with a connector portion for external connection of the electronic control module. A group of lead frames constituting terminals of the connector portion are embedded in the cover. Power source is supplied to a motor via the connector portion for external connection, the electronic control module and intermediary connectors provided at the cover. Thereby, by simplifying the cover for protecting the throttle valve.

Abstract: A marine vessel running controlling apparatus is applicable to a marine vessel which includes a propulsive force generating unit having an engine with an electric throttle. The apparatus includes a target characteristic storage unit which stores a target characteristic curve defining a target characteristic for an operation amount-engine speed characteristic, a target characteristic change inputting unit to be operated by an operator to change the shape of the target characteristic curve, and a target characteristic curve updating unit. The target characteristic change inputting unit includes an inflection point position change inputting unit and a curve shape change inputting unit to be operated by the operator.

Abstract: An throttle valve is controlled by using an electric actuator. A cover for covering one end side of the throttle valve shaft is attached to a side wall of a throttle body. A throttle position sensor unit and an electronic control module for controlling the throttle valve is attached to an inner face of the cover. The throttle position sensor and the electronic control module are contiguous to each other and connected at a position contiguous thereto. The cover is provided with a connector portion for external connection of the electronic control module. A group of lead frames constituting terminals of the connector portion are embedded in the cover. Power source is supplied to a motor via the connector portion for external connection, the electronic control module and intermediary connectors provided at the cover. Thereby, by simplifying the cover for protecting the throttle valve.

Abstract: An throttle valve is controlled by using an electric actuator. A cover for covering one end side of the throttle valve shaft is attached to a side wall of a throttle body. a throttle position sensor unit and an electronic control module for controlling the throttle valve is attached to an inner face of the cover. The throttle position sensor and the electronic control module are contiguous to each other and connected at a position contiguous thereto. The cover is provided with a connector portion for external connection of the electronic control module. A group of lead frames constituting terminals of the connector portion are embedded in the cover. Power source is supplied to a motor via the connector portion for external connection, the electronic control module and intermediary connectors provided at the cover. Thereby, by simplifying the cover for protecting the throttle valve.

Abstract: A control system for a throttle valve actuating device is disclosed. The throttle valve actuating device includes a throttle valve of an internal combustion engine and an actuator for actuating the throttle valve. A control object model is defined by modeling the throttle valve actuating device. The throttle valve actuating device is controlled based on a controlled object model so that an opening of said throttle valve coincides with a target opening.

Abstract: A throttle device in the intake section of an internal combustion engine; the throttle device including a housing part, which contains a flow cross section for an air flow. In the housing part, bearing points are provided for a throttle valve device, which can be actuated by means of an actuating drive. The actuating drive can be inserted into a receiving housing, which has first and second guide surfaces that permit the installation of the actuating drive. Fastening means are provided on the circumference surface of the receiving housing and can accommodate a closing and contacting element, which contacts electrical contacts of the actuating drive.

Abstract: An induction control system for an internal combustion engine and an operator for controlling the control valve. The system operates so as to move the control valve between an unrestricted flow position and another position wherein the flow velocity or direction is changed. The valve is moved between these positions at varying rates depending upon the engine running condition so as to provide quicker response under some conditions than others.

Abstract: A remote control assembly for rotating a throttle-valve shaft (18) rotatably mounted in a carburetor (14) including a control housing (22) having threaded fasteners for attaching the control housing (22) to a carburetor (14). A throttle conduit (28) is connected to the control housing (22) and a throttle core element (30) is movably supported in the throttle conduit (28) for movement in response to accelerator pedal inputs. A cruise control conduit (34) is connected to the control housing (22) and a cruise control core element (38) is movably supported in the cruise control conduit (34) for movement in response to cruise control inputs. A throttle pulley (40) is rotatably mounted in the control housing (22) and the throttle core element (30) is connected to the throttle pulley (40) for rotating the throttle pulley (40) in response to the movement of the throttle core element (30).

Abstract: An apparatus for automatically controlling the activation of the throttle on a carburetor on the engine of a drag race car before the start of the race while staging the car. The apparatus eliminates some of the tasks a driver must perform during the process of staging and launching a race vehicle on the starting line(such as physically depressing the throttle pedal) using a starting line throttle actuation system for Pro tree and Full tree modes for controlling the throttle opening. In both Pro and Full tree modes, the staging process is simplified by allowing the driver to stage with the throttle pedal pre-depressed in the wide open down position, with the actual opening of the throttle controlled by the starting line throttle actuation control system. The apparatus has the driver use the same staging procedure for both Pro tree and Full tree races, thus eliminating separate training that has been required for Pro and Full tree races.

Abstract: A control system for influencing the speed of a motor vehicle. The invention is characterized in that the retarder controller and the pertaining servomechanism already available in a vehicle with an installed retarder is in traction operation additionally utilized for throttling the drive engine down when a presettable allowed maximum value of the speed is exceeded.

Abstract: A running control apparatus for an automobile prevents an abnormal running state by depressing a brake pedal even when a fault takes place in the component(s) of the control apparatus. When a detected brake pedal depression stroke exceeds a predetermined value, an electric power supply to a throttle actuator is interrupted to thereby allow a throttle valve to assume a fully closed position.

Abstract: A constant-speed cruising control system for vehicles comprises a car-speed sensor, a command switch group, a car-speed memory, an actuator for driving a throttle, and a control mechanism which has a cruising control function, a resuming control function after cancelling the cruising control and controls the vehicle speed so as to coincide with a reset cruising speed stored in reponse to a reset operation during the resuming control by driving the throttle in the decelerative direction of the vehicle for the time given by subtracting set initialize time from the sum total of time the throttle is controlled in the accelerative direction of the vehicle during the time from the operation of the resume switch till the reset operation. It is possible to solve the undershooting of the vehicle speed at the transitional time from the acceleration state to the cruising state at the constant-speed.

Abstract: A throttle valve control apparatus for an internal combustion engine, which is high in driving safety, enabling the vehicle to cruise in an automatic manner while preventing a run-away condition of the vehicle includes a throttle valve in an intake pipe of the engine fixedly mounted on a valve shaft which is rotatably supported by the intake pipe, and a rotary disk rotatably mounted on the valve shaft and biased by a return spring to rotate relative to the valve shaft in the valve closing direction. The rotary disk is operatively connected with the accelerator pedal so that the rotary disk rotates relative to the valve shaft by operation of the accelerator pedal. A rotation-transmitting mechanism is connected between the rotary disk and the throttle lever for transmitting the rotation of the rotary disk to the throttle lever.

Abstract: A fixed speed control device including a predetermined vehicle operating speed controller, a release time limit set-up system, a release switch system, and a memory system, which are all electronically connected to an electronic control circuit. The fixed operating speed control device controls the speed of a vehicle so that it is commesurate with a specified preset vehicle speed, and can release itself from the controlled speed when a deviation exceeds a specified value, and properly adopt one of ten control branches to meet various requirements of vehicle operation.

Abstract: A traction control system includes a control rod connected to a throttle lever and being slidable with respect to a housing to which an accelerator pedal is connected. The control rod is movable in response to a driving wheel acceleration slip signal so as to return the throttle lever. A control device controls the movement of the control rod. A set spring acts between the control rod and the housing. The set spring has such a spring force that the set spring is not compressed by the pressing-down of the accelerator pedal in the absence of the driving wheel acceleration slip signal, so that the control rod can be moved together with the housing. The spring force of the set spring is such that during the above movement of the control rod, the set spring is compressed when the accelerator pedal is strongly pressed down.

Abstract: The governor of the invention consists of an output solenoid having a plunger operatively connected to the mechanism to be controlled. The output solenoid is a "bang-bang" type such that full power or no power is delivered to the solenoid even for small errors between the desired operating condition and actual condition of the mechanism to be controlled. The output solenoid is connected in a hydraulic circuit with a control solenoid having a control valve such that the movement of the fluid through this circuit is regulated by the control solenoid. The control solenoid is of the proportional type such that the control valve's position is directly related to the difference between the actual operating condition and the desired operating condition of the mechanism to be controlled.

Abstract: A device for interacting with a throttle of a carburetor to produce a second, constant idle speed having a ram arm with a first end engaging the throttle when the ram arm is in a forward position; a vacuum-operable diaphragm attached to the ram arm for moving the ram arm to the forward position upon application of vacuum pressure; and solenoid-operated means for further maintaining the ram arm in the forward position.

Abstract: The invention relates to a speed control system for a multiple engine air conditioning system in which two or more engines are used to drive respective compressors for operation of two or more heat pump circuits. According to the invention, the engine speed control system has a negative pressure generating circuit connected in common to the intake manifolds of two or more engines.

Abstract: A vehicle speed control device in a vehicle having a variable speed engine and drive train arrangement connecting the engine to a drive wheel therefore includes a foot pedal movable in first and second directions, a vehicle speed transducer arrangement for generating a signal in response to vehicle speeds in excess of a predetermined speed and a control arrangement for varying the value of the predetermined speed. A throttle arrangement is responsive to movement of the foot pedal in the first direction for increasing the vehicle speed and is responsive to movement of the foot pedal in the second direction for decreasing the vehicle speed. A coupling arrangement transfers movement of a movable actuator to the foot pedal, to move the foot pedal in the first and second directions. A regulating arrangement is responsive to the signal of the speed transducer arrangement for regulating the vehicle speed at or just below the predetermined speed.

Abstract: A displacement device for a throttle valve of an internal combustion engine in idling condition, has a housing, a diaphragm which is arranged in a chamber in the housing and is operatively connected to the throttle valve, a spring in the chamber, which spring acts with one end against the diaphragm, a vacuum connection to the one chamber, a connection for atmospheric pressure, a coil, and an armature which is axially displaceable in the coil, a valve body being firmly connected to the armature and keeping a connection for atmospheric pressure open or closed corresponding to its instantaneous position. A single connection for atmospheric pressure leads to the chamber and is kept open or closed by the valve body. The connection for vacuum is also kept open or closed by the valve body, the two connections being opened alternately. The valve body is acted on by the spring. The coil current is provided as control variable for the position of the throttle valve.

Abstract: A vehicle speed control system compares current vehicle speed against a target vehicle speed and automatically controls the position of the throttle valve of an engine in accordance with the difference therebetween for reducing the difference. A plurality of brake switches are provided. The system terminates the control of the position when at least one of the switches detects a depression of the brake pedal. If at least one of the switches does not detect the depression of the brake pedal when at least one of the switches detects it, an abnormality signal is generated for blocking commencement of the control of the position of the throttle valve. The abnormality signal is extinguished to enable the commencement of the control when all of the switches detect the depression of the brake pedal.

Abstract: A device for actuating a butterfly throttle valve of an internal combustion engine includes a hydraulic setting member for rotating a shaft of the throttle valve. The hydraulic setting member is driven by a branch flow of fuel delivered by a fuel pump and acting as pressure medium. The branch flow passes through a series of connection of adjustable throttles connected in a hydraulic bridge circuit. The throttles are adjusted by a regulating signal corresponding to the difference between an actual position signal delivered by a position sensor coupled to the throttle valve, and a desired position sensor coupled for example to a gas pedal of the motor vehicle.

Abstract: A pneumatic constant-velocity running apparatus employing a diaphragm type actuator in which a portion or the whole of a control circuit for the actuator is made of a hybrid IC and the hybrid IC portion with a protector is fixedly mounted onto the outer surface of an housing of the actuator. The apparatus is made compact and further be remarkably improved in an operation accuracy and in noise-proof property as well as in heat radiating property.

Abstract: In order to ensure that idling control is assuredly provided when the engine is subject to cold starts and the like, a solenoid which controls the modulation of a pressure signal via which a vacuum operated servo unit is controlled, is arranged to be fed an energization signal having a maximum energizing effect when a parameter indicative of the engine being started or having just been started is detected.

Abstract: A throttle actuator in an automatic shift mechanism of a geared transmission for shifting to overdrive automatically includes first and second displacement members capable of being displaced relative to each other, the first displacement member being connected to the accelerator pedal and the second displacement member being connected to the engine throttle, a spring interposed between the first and second displacement members for displacing them in unison, actuating means attached to the second displacement member for displacing it relative to the first displacement member for displacing it relative to the first displacement member to open or close the engine throttle, and a CPU for controlling operation of the first actuating means.

Abstract: An ajustable throttle connector for a vehicle speed control unit is disclosed. The adjustable throttle connector includes a throttle connector arm which is pivotally connected in an adjustable manner to a housing for the vehicle speed control unit. The adjustable pivotal connection is accomplished by forming a plurality of apertures in the throttle connector arm near the center thereof. A corresponding plurality of apertures are formed in the housing. A pin is inserted through a selected one of the apertures formed in the throttle connector arm and also through the corresponding one of the apertures formed in the housing to provide a fulcrum about which the throttle connector arm is free to pivot.

Abstract: A vacuum actuator for actuating the throttle valve of a vehicle is driven by a surge tank via three valves which are actuated by their respective solenoids. These solenoids are energized by their respective driver circuits. The input signal applied to each solenoid is compared with the output signal delivered from the solenoid by a comparator. The comparators for the solenoids are incorporated in a microcomputer. If any one of the comparators indicates disagreement between its two input signals, and if this disagreement persists for a given period, then the microcomputer deenergizes the corresponding solenoid. A timer for measuring the duration of the disagreement is also incorporated in the microcomputer. For example, the invention can be employed in a velocity-sustaining device for a vehicle.

Abstract: An idling speed control system for controlling idling rotational speed of an internal combustion engine. A vacuum-operated actuator having a diaphragm defining a vacuum chamber controls opening and closing of a throttle valve in response to pressures supplied from a change-over control valve to the vacuum chamber. The change-over control valve selectively supplies the vacuum chamber with a first control pressure for opening the throttle valve and a second control pressure for closing same. An electronic control unit generates an on-off control pulse signal having a pulse repetition period corresponding to rotational speed of the engine, one of on-period or off-period of the on-off control pulse signal having a predetermined constant value, and supplies the change-over control valve with the on-off control pulse signal.

Abstract: A constant-speed running control device is provided, which comprises car speed detecting means for detecting the current car speed of a vehicle, memory means for storing a given car speed, an actuator for controlling a throttle valve, setting means for causing the memory means to store the given car speed, releasing means for releasing the control of the actuator, electronic control means for controlling the actuator in such a direction as to cause the difference between the stored car speed held in the memory means and the current car speed detected by the car speed detecting means to disappear, temperature detecting means, and low-temperature release means for actuating the releasing means in response to the output of the temperature detecting means, whereby the control of the actuator is released through the releasing means when an ambient temperature lowers to thereby prevent erroneous operation and enhance reliability.

Abstract: A constant speed running apparatus has a surge tank for storing a vacuum for driving a vacuum actuator, a vacuum switch for judging the amount of vacuum stored in the surge tank, and a vacuum pump activated when the amount of vacuum stored in the tank decreases so as to supply the vacuum to the tank. When a switch for starting a constant speed running is actuated, the pump is activated for a predetermined period of time to replenish the vacuum before the vacuum switch is activated. Accordingly, it is possible to maintain the internal pressure in the surge tank at a sufficiently high level when a constant-speed running control is started, and consequently improve the response of the actuator.

Abstract: An idling speed control system for controlling idling rotational speed of an internal combustion engine. A vacuum-operated actuator having a diaphragm defining a vacuum chamber controls opening and closing of a throttle valve in response to pressures suppliedfrom a change-over control valve to the vacuum chamber. The change-over control valve selectively supplies the vacuum chamber with a first control pressure for opening the throttle valve and a second control pressure for closing same. An electronic control unit generates an on-off control pulse signal having a pulse repetition period corresponding to rotational speed of the engine, one of on-period or off-period of the on-off control pulse signal having a predetermined constant value, and supplies the change-over control valve with the on-off control pulse signal.

Abstract: An idling control for an Otto engine comprises a throttle valve positioned in a suction pipe of an engine intake manifold; a pneumatic cylinder unit operably engaged with said throttle valve by means of a positioning leg; a three-way flow control valve in fluid communication with said pneumatic cylinder unit, said valve having respective input conduits for atmospheric pressure and vacuum, and having means for alternatively transmitting said atmospheric pressure and said vacuum to said pneumatic cylinder unit, said transmitting means including opposing coils and a pulse generator having an adjustable pulse duty factor, said coils being connected to push-pull outputs of said pulse generator, the alternative positions of said control valve being determined in accordance with said duty factor, said duty factor being applied to said opposing coils simultaneously; said three-way flow control valve further includes valve seats for said input conduits and a membrane-like, freely-movable ferromagnetic valve plate havi

Abstract: An idling speed control system for controlling idling rotational speed of an internal combustion engine. A vacuum-operated actuator having a diaphragm defining a vacuum chamber controls opening and closing of a throttle valve in response to first and second control pressures supplied from a change-over control valve to the vacuum chamber. An electronic control unit generates, in response to an on-off control pulse signal having a period corresponding to rotational speed of the engine, one of on-period and off-period of the on-off control pulse signal having a predetermined constant value, and supplies the change-over control valve with the control pulse signal. Preferably, a detector is connected to the electronic control unit for detecting a change in the magnitude of a load on the engine and supplying the electronic control unit with an output signal indicative of the detected change in the load magnitude.

Abstract: A vacuum-operated actuator controls opening and closing of a throttle valve in an intake passage of an internal combustion engine in response to pressure in a vacuum chamber thereof. A change-over control valve supplies the vacuum chamber, selectively, with first and second control pressures for opening and closing the throttle valve, respectively. An electronic control unit controls the engine idling rotational speed by generating an on-off control pulse signal having a period corresponding to the engine rotational speed, and supplying the change-over control valve with the on-off control pulse signal to cause same to supply the vacuum chamber with the first or second control pressure.

Abstract: An automatic speed controller for use of a vehicle. The automatic speed controller maintains the actual vehicle speed into a preset vehicle apeed. The controller has a vacuum type actuator which is operated by a diaphragm. The diaphragm is actuated buy controlling the volume of an atmospheric pressure to that of a vacuum pressure. If the controller is out of order by any troubles, the atmospheric pressure is positively introduced into the actuator, thereby preventing the actual vehicle speed from being more than the preset vehicle speed.

Abstract: An automatic speed control mechanism for motorcycles or the like having a wire operating mechanism for positively connecting the accelerator grip to the throttle control of the engine. The automatic speed control includes a vacuum operated motor that is connected to the throttle wire system through a lost motion connection so that the manual throttle operation can operate unencumbered by the automatic speed control system.

Abstract: A throttle control apparatus for an internal combustion engine for a motor cycle, comprising a manually operated rotatable throttle actuating grip member, a first linkage cable for providing driving connection selectively in one of two opposite directions from the grip member to the engine throttle valve, a control circuit for producing a control signal when actuated, drive means responsive to the control signal for producing a driving force in one direction, a throttle regulator unit for providing driving connection from the drive means to the throttle valve, and a second linkage cable for transmitting the driving force to the throttle regulator unit.

Abstract: A position control device for use in association with a foot pedal member controlling the fuel flow to an engine of a vehicle. The device includes an elongated and hollow chamber means and an actuator piston slidably disposed in the chamber means and movable between first and second positions therein. The first position represents a position of maximum fuel supply to the engine. Structure separately supporting the foot pedal member is provided for movement between first and second positions but permitting an operative connection of the foot pedal member to the actuator piston for movement along a path.

Abstract: An automatic speed control mechanism for a motorcycle embodying an actuator device for automatically positioning the throttle of the engine. The automatic device is able to generate sufficient force so as to overcome the normal closing bias of the throttle but has insufficient force to resist throttle closing movement of the manual actuator so that the operator may manually override the automatic speed control and reduce the speed of the motorcycle.

Abstract: Two embodiments of automatic speed control devices for motorcycles that permits release of the device from automatic mode in response to throttle closing movement of the accelerator grip. In one embodiment, the release is effective by permitting a protective sheath of a wire actuator of the throttle mechanism to move in response to throttle closing movement of the accelerator grip and this movement is employed to actuate a switch. In another embodiment, a control wire and surrounding housing afford a switch that is closed when the accelerator grip is moved in a closing direction.

Abstract: A modulated vehicle cruise control system includes a source of vacuum, a servo transducer or control unit connected to the source of vacuum, an engine throttle position servo connected to the servo, a speed sensor and a logic circuit or command module. A modulator is disposed in series with and between the control unit and the source of vacuum. The modulator limits opening movement of the engine throttle by modulating communication of vacuum to the servo to prevent inefficient engine operation.

Abstract: An actuator for controlling the pressure in an internal space defined by a spring-biased diaphragm and a housing by solenoid valve. The internal space is selectively communicated with a negative pressure port or an atmospheric pressure port through a first solenoid valve. The pressure in the internal space is determined by the ratio of a time period in which it is communicated with the negative pressure port to a time period in which it is communicated with the atmospheric pressure port, and the position of the diaphragm is determined accordingly. Another solenoid valve for releasing negative pressure is included for safety. To the housing fixed are a microcomputer for receiving status signals from a vehicle speed sensor, clutch ON/OFF sensor, brake ON/OFF sensor, etc. to generate a solenoid valve opening and closing signal, and a printed board incorporating an electrical driver adapted to energize the solenoid valve in response to said signal.

Abstract: A device for controlling the throttle position of a carburetor during an accelerator release stage, in accordance with the speed of the engine. The device includes a vacuum motor which acts on a control lever associated with the carburetor throttle and which is in fluid communication with the intake suction manifold of the engine and with the atmosphere. An electromagnet device is energized by a control device which receives signals representing various engine parameters as detected by sensing devices. The electromagnet device includes a movable keeper including a bushing which slides between a pair of abutments under the effect of the magnetic field created by the electromagnets of the electromagnet device and of a spring which opposes the force applied by the magnetic field. The bushing includes a valve member which controls a pipe in order to place the vacuum motor in communication with the atmosphere.

Abstract: In a rotational speed control apparatus for an internal combustion engine in which a signal-responsive diaphragm, whose controlling position is determined by a controlled negative pressure signal, is provided with a valve member controlling to negative pressure acting upon a driving diaphragm controlling the opening of a throttle valve, the negative pressure acting upon the driving diaphragm, when the controlled negative pressure signal is detected to be not normal, is controlled to be shifted to the level at which the driving diaphragm is rendered substantially non-operable.

Abstract: A pneumatically operated speed governor (26) moves an engine throttle member (10) for controlling the speed of a vehicle. The governor includes a pneumatically operated actuator having an output connected to the engine throttle member. A pivotally mounted valve member (44) is positioned intermediate a vacuum supply orifice (46) and an atmospheric air orifice (48) and supplies a pneumatic signal to the actuator. An internal speed sensor (82) responsive to vehicle speed has an output member (100) which reacts against an improved, self-wiping minimum speed switch (102) and a set-speed control member (52) which in turn reacts against the pivotally mounted valve member (44) for varying the position of the valve member as the vehicle speed tends to fall below or rise above a predetermined set speed.