Abstract: A seat suspension is provided that has a damper unit which is connected between the seat and the chassis on which the seat is mounted. The damper can be switched between soft and hard settings. The damper switching is controlled based on the relative position of the seat and one of the relative or absolute velocity of the seat. When the seat and the chassis are moving in the same direction the damper is set to soft, (producing a low damping effect), while when the seat and chassis are moving in opposite directions the damper is switched to hard (producing a high damping effect).

Abstract: A system for controlling a fluid pressure such a brake fluid pressure of a vehicle includes a pressure control cylinder having a control piston for varying a pressure of a confined fluid, and a motor for producing a mechanical force for actuating the control piston. To reduce the load of the motor, a hydraulic assist circuit is interposed between the motor and the control piston. The hydraulic assist circuit creates a hydraulic assist pressure by receiving the force of the motor, and converting the assist pressure into a linear motion of the control piston. The mechanical force of the motor is converted to hydraulic assist pressure through a pressurizing piston. The hydraulic assist pressure created by the pressurizing piston is exerted against a working piston. The working piston is connected to the control piston.

Abstract: A system for controlling a fluid pressure includes a pressure modulating cylinder unit having a piston and a cylinder housing defining first and second fluid chambers separated by the piston, a cutoff valve unit for isolating the first and second chambers from a pressure source and from each other, and a motor unit for pushing and pulling the piston to vary the fluid pressure in the first chamber. When the system is used for controlling a brake fluid pressure of a vehicle, the first chamber is connected with a wheel cylinder, and the valve unit is arranged to isolate the wheel cylinder and the first and second chambers from a master cylinder.

Abstract: A suspension control system for automotive vehicles automatically adjusts the damping strength of variable shock absorbers or other dampers in accordance with road surface conditions as recognized by frequency analysis of a vehicle height or vibration sensor signal. The sensor signal reflects vertical displacement of the vehicle body from the road surface and includes high-frequency components due solely to displacement of the wheels or unsprung mass relative to the road surface and low-frequency components due to displacement of the vehicle body or sprung mass. The sensor signal is filtered into these separate frequency bands, the amplitude of each of which is compared to a corresponding reference level.

Abstract: A slip suppressive drive control system derives an optimal wheel slippage for slip control mode operation on the basis of an actual engine speed, a vehicle speed and the wheel speed of a driving wheel. A target engine speed is derived based on the derived optimal wheel slippage so that optimal wheel slippage is obtained at the target engine speed. The system is responsive to wheel slippage which is derived on the basis of the vehicle speed and wheel speed on the driving wheel, to perform slip control mode operation by performing fuel cut-off to shut down fuel supply for the engine in order to adjust the actual engine speed to the target engine speed.

Abstract: A suspension control system for automotive vehicles automatically adjusts the damping strength of variable shock absorbers or other dampers in accordance with road surface conditions as recognized by frequency analysis of a vehicle height or vibration sensor signal. The sensor signal reflects vertical displacement of the vehicle body from the road surface and includes high-frequency components due solely to displacement of the wheels or unsprung mass relative to the road surface and low-frequency components due to displacement of the vehicle body or sprung mass. The sensor signal is filtered into these separate frequency bands, the amplitude of each of which is compared to a corresponding reference level.

Abstract: An anti-skid brake control system is associated with a control system for a power train which controls power train operation mode between a four-wheel drive mode, in which all four wheels are coupled with an automotive internal combustion engine to be distributed torque according to a controlled distribution ratio of an engine driving torque, and a two-wheel drive mode, in which two auxiliary driving wheels are disconnected from the engine to be free from engine driving torque and two driving wheels are connected to the engine to receive the engine driving torque. The anti-skid brake control system is so associated with the power train control system as to normally set the power train operation mode into the two-wheel drive mode during active state of anti-skid brake control, and to set the power train operation mode into the four-wheel driven mode in response to wheel slippage at the primary driving wheels greater than a predetermined threshold value.

Abstract: A mechanism for supporting a head carriage provided with a magnetic head to magnetically record still image information or the like into a magnetic disc or reproduce such information therefrom. In the support mechanism, the two ends of a lead screw having a threaded portion almost in the center portion thereof are respectively received by two bearings each having two, substantially perpendicularly intersecting surfaces, and the head carriage, which can be guided and moved by the lead screw, is also provided with two, substantially perpendicularly intersecting surfaces touchable with a shaft of the lead screw. By energizing the head carriage in a given direction by a spring, the head carriage two intersecting surfaces can be brought into contact with the lead screw and the lead screw can be brought into contact with the intersecting surfaces of the respective bearings.

Abstract: An anti-skid brake control system comprises a limiter which provides an upper limit of variation of wheel speed indicative data. The limited wheel speed indicative data is derived with respect to each wheel. The greatest limited wheel speed indicative data is selected as vehicle body speed indicative initial data. The anti-skid brake control system derives a projected vehicle body speed indicative data by adding an integrated value of a longitudinal acceleration to the aforementioned vehicle body speed indicative initial data. The integrated value is provided with a predetermined offset value for compensating for error caused in a longitudinal acceleration sensor.

Abstract: An anti-skid brake control system two mutually different mode for projecting the vehicle body speed representative data. In the first mode, the vehicle body speed representative data is derived on the basis of an instantaneous wheel speed data which is latched upon initiation of vehicular braking operation or upon detection of vehicular braking deceleration, and an integrated value of a longitudinal acceleration indicative signal. On the other hand, in a second mode, the vehicle body speed representative data is derived on the basis of the initially latched instantaneous wheel speed data and a fixed value of wheel deceleration gradient data. A first vehicle body speed representative data derived through the first mode of operation and a second vehicle body speed representative data derived through the second mode of operation are selectively used as the vehicle body speed representative data.

Abstract: An anti-skid brake control system includes a device for detecting the friction level of a road surface. The system performs mutually different modes of arithmetic operation for deriving wheel acceleration data on the basis of wheel speed monitoring data. Respective modes of arithmetic operations are provided different levels of response characteristics and noise elimination levels adapted for road friction levels. The system selects one of the arithmetic operation modes for deriving the wheel acceleration data depending upon the friction level on the road surface.

Abstract: A mechanism for supporting a head carriage provided with a magnetic head to magnetically record still image information or the like into a magnetic disc or reproduce such information therefrom. In the support mechanism, the two ends of a lead screw having a threaded portion almost in the center portion thereof are respectively received by two bearings each having two, substantially perpendicularly intersecting surfaces, and the head carriage, which can be guided and moved by the lead screw, is also provided with two, substantially perpendicularly intersecting surfaces touchable with a shaft of the lead screw. By energizing the head carriage in a given direction by a spring, the head carriage's two intersecting surfaces can be brought into contact with the lead screw, and the lead screw can be brought into contact with the intersecting surfaces of the respective bearings.

Abstract: A suspension control system for an automotive vehicle automatically adjusts the damping strength of variable shock absorbers or other dampers in accordance with road surface conditions as recognized by frequency analysis of a vehicle height or vibration sensor signal. The sensor signal reflects vertical displacement of the vehicle body from the road surface and includes high-frequency components due solely to displacement of the wheels or unsprung mass relative to the road surface and low-frequency components due to displacement of the vehicle body or sprung mass. The sensor signal is filtered into these separate frequency bands and the amplitude of each is compared to a corresponding reference level to give an indication of the irregularities in the road surface. Specifically, a high-amplitude low-frequency component indicates large-scale bumps and dips capable of bouncing the vehicle whereas a strong high-frequency component reflects a rough-textured road surface, such as gravel.

Abstract: In order to ensure riding comfort and driving stability in an automotive suspension system, the nature of the effect of the damping force generated by the suspension system is observed. When the damping characteristics of the suspension system are too hard, resulting in amplification of vibrations in the suspension system, the damping characteristics are softened to ensure satisfactory riding comfort. Therefore, according to the present invention, an automotive suspension system has variable damping characteristics which depend on the nature of the damping force produced in response to bounding and/or rebounding motion of the vehicle so as to optimize damping characteristics to achieve both riding comfort and driving stability. In the preferred embodiment, a suspension control system uses the vibration frequency of a sprung mass and the relative speed between the sprung mass and an unsprung mass as control parameters representing the nature of damping force.

Abstract: A device for use in exhaust gases of internal combustion engines to detect changes in air/fuel ratio. The device has a body of a transition metal oxide, such as TiO.sub.2, with a first pair of electrodes attached thereto to measure a change in the resistance of the transition metal oxide in response to a change in the air/fuel ratio. The device includes a combination of a porous layer of an oxygen ion conductive solid electrolyte such as ZrO.sub.2 arranged such that the exhaust gas comes into contact with the transition metal oxide body always by diffusion through the solid electrolyte layer and a second pair of electrodes arranged so as to force a DC current to flow in the solid electrolyte from selected one of these electrodes to the other.

Abstract: An electrostatic type fuel measuring device comprises a pair of oppositely arranged electrodes separated by insulating spacers immersed in liquid fuel in a tank so that a variation of the electrostatic capacity between the electrodes due to a variation in the liquid fuel level is detected electrically and the fuel amount is measured and indicated.

Abstract: A vibration sensor for an automotive vehicle having a multi-peak vibration characteristic of wider responsiveness and of a higher S/N ratio. The vibration sensor comprises a plurality of piezoelectric vibrators so arranged that the piezoelectric voltage signals from the vibrators are synthesized in reverse polarity between two elements having two adjacent resonant frequencies, when the element are deformed in the same direction. Therefore, the voltages are synthesized in the same polarity, when engine knocking frequency lies between two adjacent sensor resonant frequencies, because a vibrator is 180 degrees out of phase with another adjacent vibrator.

Abstract: The flow rate is determined from the heat transferred from an electrically heated wire stretched in a fluid flow to the fluid. The wire is placed not on a plane normal to the flow but within a section of the fluid passage bounded by two spaced planes normal to the flow. Preferably the wire is composed of series of line segments which are distributed evenly not only around the central axis of the passage but also in the direction of the flow so that the heat release from the wire in its entirety corresponds to the mean value of fluid velocities at various points.

Abstract: In a control system for an internal combustion engine which receives a signal representing an operational parameter of the engine, a signal processor is disclosed which eliminates spurious signals. The processor comprises a memory which stores a plurality of sequential values of the signal, and an averager which averages at least some of the stored values and outputs the average as an output signal.

Abstract: In order to ensure riding comfort and driving stability in an automotive suspension system, the nature of the effect of the damping force generated by the suspension system is observed. When the damping characteristics of the suspension system are too hard, resulting in amplification of vibrations in the suspension system, the damping characteristics are softened to ensure satisfactory riding comfort. Therefore, according to the present invention, an automotive suspension system has variable damping characteristics which depend on the nature of the damping force produced in response to bounding and/or rebounding motion of the vehicle so as to optimize damping characteristics to achieve both riding comfort and driving stability. In the preferred embodiment, a suspension control system uses the vibration frequency of a sprung mass and the relative speed between the sprung mass and an unsprung mass as control parameters representing the nature of damping force.