Abstract: A vehicle speed control system is disclosed which is primarily intended for heavy vehicles and which is arranged to `anticipate` an uphill section of road immediately following a downhill section, so as to prevent loss of momentum gained on the downhill section. A comparator compares an actual speed signal Vs with a driver-settable desired speed signal Vr and produces an error signal. A level changing circuit produces an output equal to Vr in normal circumstances, but which follows Vs when the vehicle accelerates downhill. This output is fed through a memory via a switch which is open when an acceleration-deceleration unit detects that the vehicle has reached the foot of the hill. This memory therefore stores a signal Vr' representing the speed at that time, and the comparator therefore increases the engine power when the vehicle speed has fallen below this augmented reference speed, instead of waiting for the speed to fall to the original reference.

Abstract: Linkage is disclosed for adjusting the position of a diesel engine injection pump control rack in dependence on the position of the driver's accelerator pedal and also on a system for automatically maintaining the vehicle speed at a desired value. The injection pump rack is positioned by means of a pneumatic piston-cylinder assembly and connecting linkage. The pressure in the piston-cylinder assembly is adjusted by means of a driver-controlled valve in a supply line from a pressure source, and this valve is adjusted by the driver's accelerator pedal. A normally open valve is also connected in the pressure circuit and a normally closed exhaust valve is provided. When the automatic speed control system is in operation, the driver fully opens the driver-controlled valve (by fully depressing his foot pedal) and the automatic system adjusts the other valves to hold the speed at the desired value.

Abstract: An automatic speed control system is disclosed in which an error signal Ve, representing the speed error of the vehicle, is added to a ramp voltage, ramping between fixed values, to produce a control signal Vc. Two comparators compare Vc with upper and lower limits, respectively, so as to produce a pulse train on one of two lines depending on the sign of the error and having a mark-space ratio depending on the magnitude of the error. A circuit responds to the first pulse to occur in the pulse train from one of the two comparators when the vehicle is accelerating towards and overshooting a new desired speed and, via a switching circuit, lowers the upper limit applied to that comparator so as to lengthen the first pulses and help to reduce overshoot of the desired speed. When the vehicle ceases accelerating, the upper limit is switched back to the desired value, and is also switched back to its original setting when the speed falls by a preset amount.

Abstract: An actuator which forms part of speed control apparatus for controlling the forward speed of a vehicle, or the rotational speed of an engine, where it is desired to bring the speed control apparatus into operation at the discretion of the operator, has a reversible electric motor which receives a speed correction signal related to the difference between the actual speed and the desired speed. An electromagnetic clutch is provided which includes a rotor driven by the motor, and a clutch ring mounted via a spring from a pulley having a double-acting connection to the throttle lever of the engine. The clutch is energized on engagement of the speed control to bring the rotor and clutch ring into driving engagement, whereby the throttle lever is driven by the electric motor via the pulley and double-acting connection.At any instant, the position of the clutch ring and pulley corresponds with that of the throttle lever.

Abstract: For cooling the working face of mechanical working elements, such as bearings, rotary seals and friction devices, the cooling fluid flows through a passage which is located behind the working face and contains a porous thermally-conductive mass having interconnecting pores. The conductive material of the porous mass is in intimate thermal contact with the wall behind the working face and acts as a heat exchanger having an extended heat transfer surface. The porous mass preferably comprises a sintered highly-conductive material.

Abstract: A vehicle speed control system is disclosed in which a signal Vs representing actual vehicle speed is, when the vehicle is running at a desired speed, momentarily fed into, and then stored in, a memory. The memory therefore produces a signal representing desired speed. An error amplifier compares the signal Vm with a signal Vf which represents actual vehicle speed and which is derived from Vs via a filter. Any speed error causes a drive circuit to adjust the throttle of the vehicle engine so as to tend to correct the vehicle speed error. The vehicle-speed-dependent signal Vf is derived from the actual speed of the engine of the vehicle, and this signal is also fed to a comparator which compares it with a reference signal Vr representing an upper or lower limit for engine speed. When the comparison indicates that the engine speed has exceeded the level represented by the reference Vr (e.g.

Abstract: A motor vehicle speed-control system includes a bellows chamber having a movable wall connected to the engine throttle. The pressure of the gas in the chamber is controlled by two electromagnetic valves, the first electromagnetic valve being energized with electrical pulses to repetitively connect the bellows chamber alternatively to atmosphere and vacuum, and the second electromagnetic valve being spring-biassed so that, when deenergized, it vents the chamber to atmosphere to ensure rapid closure of the throttle, and when energized, closes the said vent. An auxiliary fail-safe brake-pedal valve is provided. An audible signal is produced by a flow of air in the event of malfunctioning of the actuator device.

Abstract: A vehicle speed system is described in which an electrical signal representing actual vehicle speed is compared with a stored signal representing desired vehicle speed. Any speed error is used in a servo loop to generate a control signal which tends to reduce the error to zero. In addition, signals representing the actual and desired vehicle speeds are compared in a comparator unit so as to produce a disabling signal when the actual vehicle speed either exceeds the desired speed by more than a predetermined amount, or falls below the desired speed by more than a predetermined amount, (e.g. because road conditions prevent the vehicle engine from driving the vehicle at or close to the desired speed). This enabling signal is used to switch the control system out of operation.

Abstract: A flow control means has two opposed co-operating faces between which fluid is introduced at an inlet zone so as to flow radially towards at least one downstream zone, one face being loaded or loadable towards the other face and comprising a pressure-deflectable elastic or elastically loaded element which is deflectable to provide a clearance between the co-operating faces which is convergent towards the or each downstream zone.

Abstract: A system for controlling the speed of a motor vehicle comprises means deriving a first electrical signal having a mean level related to the actual speed of the vehicle and an alternating component whose amplitude is related to the actual speed of the vehicle, means storing a second electrical signal having a mean level related to a desired value for the vehicle speed and substantially free of any alternating component, means arranged to compare the first and second electrical signals whereby to produce an error signal having a mean level related to the difference, if any, between the actual and desired vehicle speeds and an alternating component related to the actual vehicle speed, and speed correcting means responsive to the amplitude of the error signal for correcting the actual speed of the vehicle.

Abstract: A vehicle speed control system is disclosed where the vehicle speed is automatically controlled by an electro-pneumatic actuator subjected to the controlled application of sub-atmospheric pressure. A dump valve is normally held closed by an energized electrical coil but opens when the coil is de-energized and connects the actuator to atmosphere and shuts off the control system. The coil is connected to an electrical power source through a disabling switch which is intended to be opened automatically when the driver operates the vehicle brakes and thus overrides the control system. To ensure that the override is effective even if the disabling switch fails to open, a brake-pedal operated switch connects one end of the coil to the same terminal of the power supply as is connected to the other end of the coil by the disabling switch. Therefore, when the brakes are operated both sides of the coil receive the same potential and the coil is de-energized even if the disabling switch fails to open.

Abstract: A positive clearance radial face seal characterized in that at least one of its two opposed sealing faces comprises a pressure-deflectable elastic or elastically loaded element which deflects, in steady state operating conditions, to provide a clearance between the sealing faces which converges in the radial direction towards the downstream zone of the seal, the deflection changing with variations in the operating conditions in a manner tending to restore the steady state clearance.

Abstract: The invention relates to an actuator device for a motor vehicle speed-responsive system, the device being operable to actuate the throttle valve or the like of the internal combustion engine of the vehicle. The actuator device comprises a bellows device defining a first chamber partly bounded by a movable wall and a fixed wall, and communicating with two further chambers defined by associated housings carried by the said fixed wall. One of the further chambers contains a first electro-magnetic control valve fed by a D.C. voltage, and operable to control an orifice through which the first chamber communicates with atmosphere. The other of the further chambers contains a second electro-magnetic control valve fed both by said D.C. voltage and by a pulsed voltage, and operable to control both an orifice through which the first chamber communicates with atmosphere and an orifice through which the first chamber communicates with a source of gas at sub-atmospheric pressure.

Abstract: A system for limiting the engine-driven speed of a vehicle (e.g. a truck) includes an override circuit to enable engine power to be produced when the vehicle exceeds the pre-set speed, provided that the vehicle is decelerating rapidly, such as occurs when the vehicle has coasted down a steep incline and is then running uphill. The system may include an interlock to prevent the override action until the engine power has first been reduced to a predetermined minimum.

Abstract: A system for controlling the speed of a motor vehicle has a speed detector which produces a first electrical signal having a mean level relating to the actual speed of the vehicle and an alternating component whose amplitude is also related to the actual speed of the vehicle. A memory is provided for storing a second electrical signal which has a mean level related to the required vehicle speed and which is substantially free of any alternating component. A comparator compares the first and second electrical signals and therefore produces an error signal which has a mean level corresponding to the difference (if any) between the actual and required vehicle speed and an alternating component related to the actual vehicle speed. A servo responds to the amplitude of the error signal to adjust the actual speed of the vehicle towards the required value.

Abstract: The invention relates to a mechanism for actuating the carburetor throttle or fuel injection pump rack of an internal combustion engine. The mechanism comprises a ball screw device including an axially fixed nut rotatable by a reversible electric motor to axially reciprocate a screw concentrically within the nut and connected to the engine throttle or rack. Within and axially fixed relative to the nut is a caged ball arrangement which, when the cage is allowed to rotate, couples the nut to the screw to produce said axial displacement, but when the cage is blocked against rotation, causes the nut to freewheel. Stops carried by the screw are provided to engage and block the cage at each end of the axial travel of the screw to determine the stroke length thereof, and limit switches are provided actuated at each end of the stroke, to reverse the motor.

Abstract: A circuit arrangement is disclosed for protecting against overload electrical equipment such as an electric motor, and any mechanical equipment driven thereby, such as a power actuator. Two light emitting diodes are connected in parallel with each other (with opposite polarity) and in parallel with a series impedance in the power supply circuit of the motor so that each produces a light output in response to an overload current of appropriate polarity in the motor. Associated with each diode is a respective phototransistor which responds to the light output from the associated diode and, via a respective control circuit, operates a switch to interrupt the load current.

Abstract: In an electronic speed responsive system for a motor vehicle, a first voltage proportional to an actual speed of the vehicle is compared with a reference voltage representing a desired cruise speed in order to produce an output error signal related to the difference between said first voltage and said reference voltage, the desired cruise speed is stored in a memory, and a control logic and safety circuit for rendering the system operative and inoperative has a memory cancel facility which cancels the previously memorized cruise speed stored in the memory when a driver of the vehicle makes an action associated with bringing the vehicle into, or preparatory to driving the vehicle from, a parked condition.

Abstract: In a data processing system and method, particularly for processing data derived from a gauge which is measuring the thickness of continuous metal strip issuing from a metal processing plant, the value of the measurement data is sampled at successive time instants and the sampled values are processed such as to derive their mean and standard deviations. The successive time instants are randomly or psuedo-randomly distributed in time so as to avoid the possibility of the values of the data samples being affected by, or failing to record, any cyclical variations in the measurement data. The processed data may be used to exert a control function on the processing plant.