Abstract: A method is provided for measuring a pressure of a hydraulic fluid that is supplied from a hydraulic fluid control device (1) to a operation device (6). The method includes measurement of a first pressure (Pm) and a second pressure (Pa). The first pressure is the pressure of the hydraulic fluid within a first flow path (P3 to P8) connecting a pressure control unit (3) and the operation device. The second pressure is the pressure of the hydraulic fluid within a second flow path (P11, P12) connecting an accumulator (22) and the pressure control unit. Then, a stabilization time (T) is determined. The stabilization time is the time when a pressure gradient per unit time of the second pressure become to be smaller than a predetermined value. Thereafter, a pressure (Pw) of the hydraulic fluid at the operation device is determined based on the first pressure that is measured at the stabilization time or at a time immediately after the stabilization time.

Abstract: A piston-cylinder mechanism includes a cylinder (50) that defines a cylindrical bore (51). Two pistons (52, 53) are disposed within the cylindrical bore, so that a first pressure chamber (57), a second pressure chamber (58) and a third pressure chamber (59) are defined within the cylindrical bore. The first pressure chamber and one of the second and third pressure chambers individually receive a supply of a pressurized fluid. The pressurized fluid is delivered individually from the second pressure chamber and the third pressure chamber to respective external devices (16, 17). A valve (60; 160) is arranged between one of the second pressure chamber and the third pressure chamber and the corresponding external device. The valve is operable to open and close when the one of the second pressure chamber and the third pressure chamber is expanded and contracted, respectively, due to the movement of the pistons.

Abstract: A hydraulic pressure control device is provided which is capable of pressure reduction and pressure increase by electronic control without changing over hydraulic circuits, and which is reliable and simple in structure, and a vehicle brake device using it is provided. A pressure chamber and an offset spring are added to a hydraulic pressure control valve in which by moving a spool valve to a position corresponding to brake operating force, thereby changing over connections between the output port and the discharge port and between the output port and the input port and adjusting the degrees of opening of valve portions, thereby controlling the hydraulic pressure at the output port to a value corresponding to the brake operating force. By introducing a pressure P1 adjusted by a pressure-adjusting valve into the pressure chamber and lowering the hydraulic pressure in the pressure chamber in the range of P1 to 0 for pressure reduction by electronic control.

Abstract: A method of controlling a pump-driven type vehicle hydraulic brake system which can suppress pulsation of brake hydraulic pressure and makes it possible to accurately and quickly apply brake hydraulic pressure is provided. Using an equation between the pressure rising speed of the hydraulic pressure in the master cylinder and the approximate required driving force of the motor, the driving force of the motor is set from the pressure rising speed of the detected hydraulic pressure. The driving force of the motor is controlled to minimize the hydraulic pressure difference between the brake hydraulic pressure increased by the preset driving force and the hydraulic pressure in the master cylinder, thereby bringing the brake hydraulic pressure substantially close to the hydraulic pressure in the master cylinder.

Abstract: A poppet type solenoid valve used in an electronically controlable vehicle hydraulic brake system is proposed which suppresses sound and vibration and simultaneously eliminates malfunction.

Abstract: A method of controlling a hydraulic pressure source-drive type vehicle hydraulic brake system which would not make the driver feel a delay in the effect of braking, and in which the braking force acts quickly and reliably even during urgent braking. A stroke sensor for detecting the pedal depressed amount in the initial play area is provided. By activating a motor for a pump for supplying brake fluid to a wheel cylinder beforehand when the stroke sensor detects that the pedal depressed amount has reached a predetermined threshold, the time needed to depress the brake pedal to the terminal position of the initial play area and the delay time in response of the actuation of the motor are overlapped to shorten the time from the start of depressing of the brake pedal to the actuation of the brake.

Abstract: A pressure-responsive type pressure holding valve is proposed which serves to hold the hydraulic pressure in a circuit connected to a spool valve. A piston valve biased by a spring is mounted in a housing formed with a valve chamber, a small-diameter bore and a large-diameter bore. The outer periphery of the small-diameter portion of the piston valve is sealed by a seal member. A first port opened and closed by a valve head at the tip of the piston valve is connected to a circuit that needs pressure holding, a second port to a circuit in which minute leak can occur, and a third port to a source of hydraulic pressure for opening the valve.

Abstract: A hydraulic pressure control device is provided in which a proportional pressure control valve is actuated by operating the brake pedal to adjust the hydraulic pressure supplied from a pressure source to the wheel brakes to a value corresponding to the pedal operating amount. Also, a brake device for a vehicle using it is provided. The proportional pressure control valve is integrated with a hydraulic pressure generator to transmit the input from the brake pedal to a spool valve in the control valve through a first piston, first spring, second piston and second spring of the hydraulic pressure generator. If the pressure source or the wheel brakes in a first line fail, after the second piston has made a full stroke, brake fluid in a fluid chamber is pressurized, so that the hydraulic pressure generated is supplied to wheel brakes in a second line through a copy valve which is open.

Abstract: A hydraulic pressure control device is proposed in which using a proportional pressure control valve having a built-in spool valve, the hydraulic pressure for wheel brakes is adjusted to a value corresponding to the magnitude of an external force applied to the spool valve, non-electrical pressure adjustment can be done both in a normal state and in an emergency, and the structure is simplified. The brake pedal is coupled through a spring to the spool valve of the proportional pressure control valve having a solenoid for generating a spool-driving force, and the brake pedal force is applied to the spool valve as an external force so that not only in an emergency but in a normal state, pressure is adjusted by the brake pedal force.

Abstract: A control method of a hydraulic pressure source-driving type vehicle hydraulic brake system is provided in which water hammering or worsening of the brake feeling does not occur when brake liquid is replenished through a replenish passage. A motor for driving a pump is actuated at a full driving force with an on-off valve in the brake liquid replenish passage opened in the stage in which the hydraulic pressure difference between the master cylinder pressure and the brake hydraulic pressure is small. Also, in the stage in which the brake hydraulic pressure is increased, so that the hydraulic pressure difference from the master cylinder hydraulic pressure has entered a predetermined range, a solenoid valve in the replenish passage is closed to return to the normal control in which the driving force of the motor is controlled so as to correspond to the hydraulic pressure difference.

Abstract: A method of controlling a pump-driven type vehicle hydraulic brake system which can suppress pulsation of brake hydraulic pressure and makes it possible to accurately and quickly apply brake hydraulic pressure is provided. Using an equation between the pressure rising speed of the hydraulic pressure in the master cylinder and the approximate required driving force of the motor, the driving force of the motor is set from the pressure rising speed of the detected hydraulic pressure. The driving force of the motor is controlled to minimize the hydraulic pressure difference between the brake hydraulic pressure increased by the preset driving force and the hydraulic pressure in the master cylinder, thereby bringing the brake hydraulic pressure substantially close to the hydraulic pressure in the master cylinder.

Abstract: A control method of a hydraulic pressure source-driven type vehicle hydraulic pressure brake system in which no irritating noises or vibrations are produced during stoppage of the vehicle and which does not consume electric power in waste. When the vehicle stops and the surroundings become quiet, by detecting stoppage of the vehicle by a sensor for detecting the rotation of a wheel, stopping a motor for a pump for producing brake hydraulic pressure, and opening a solenoid valve in a master cylinder passage bringing the master cylinder and the wheel cylinder into communication with each other, it is possible to prevent noises or vibrations from the motor and wasteful consumption of electric power.

Abstract: A control method of a hydraulic pressure source-driving type vehicle hydraulic brake system is provided in which water hammering or worsening of the brake feeling does not occur when brake liquid is replenished through a replenish passage. A motor for driving a pump is actuated at a full driving force with an on-off valve in the brake liquid replenish passage opened in the stage in which the hydraulic pressure difference between the master cylinder pressure and the brake hydraulic pressure is small. Also, in the stage in which the brake hydraulic pressure is increased, so that the hydraulic pressure difference from the master cylinder hydraulic pressure has entered a predetermined range, a solenoid valve in the replenish passage is closed to return to the normal control in which the driving force of the motor is controlled so as to correspond to the hydraulic pressure difference.

Abstract: A method of controlling a hydraulic pressure source-drive type vehicle hydraulic brake system which would not make the driver feel a delay in the effect of braking, and in which the braking force acts quickly and reliably even during urgent braking. A stroke sensor for detecting the pedal depressed amount in the initial play area is provided. By activating a motor for a pump for supplying brake fluid to a wheel cylinder beforehand when the stroke sensor detects that the pedal depressed amount has reached a predetermined threshold, the time needed to depress the brake pedal to the terminal position of the initial play area and the delay time in response of the actuation of the motor are overlapped to shorten the time from the start of depressing of the brake pedal to the actuation of the brake.

Abstract: An electrostatic recording medium is disclosed comprising a recording layer, a conductive layer, and a support, the conductive layer being a dried coating film of a mixture composed of (A) a polyurethane binder resin prepared by reaction of a polyester and a polyisocyanate, and (B) a predispersion of carbon black.

Abstract: An electrostatic recording member comprising a recording layer, an electrically conductive layer and a support, wherein the electrically conductive layer is composed of from 2 to 40 parts by weight of electrically conductive micro-fine powder dispersed in from 60 to 98 parts by weight of an organic polymer binder, and has a surface resistivity of 10.sup.6 to 10.sup.8 Ohms.

Abstract: An electrostatic recording medium for use in an electrographic process for forming an electrostatic latent image, and method for making such a recording medium, which includes a base, a resistance layer on the base, an adhesive layer on the resistance layer and a recording layer laminated to the resistance layer through the adhesive layer, the adhesive layer being made of a mateial so that the volume resistivity of the resultant recording medium is relatively unaffected by changes in humidity conditions.

Abstract: An electrostatic printing apparatus having a transfer medium with a charge retentive surface for forming an electrostatic latent image, and a developer to develop the electrostatic latent image on the transfer medium for transfer to a support material. An array of printing electrodes supported by a flexible insulator abutting the transfer medium are uniformly spaced from the transfer medium.

Abstract: A display and printing method using an electrochromic imaging material. The electrochromic material forms a colored image in response to the formation of an image pattern on a photoconductive surface. The electrochromic material is between an electrode and the photoconductive surface when image formation takes place. The image may be utilized in a display device or in printing.

Abstract: An electrostatic printing method for developing an electrostatic latent image on a recording member by first developing the image by the "electrostatic developing" method in which a liquid developer comprising an insulating liquid vehicle and a solid colorant is electrostatically attracted and applied only to the electrostatic latent image, and then further developing the image, by "liquid developing" in which an insulating liquid miscible with the vehicle used in the electrostatic developing step and containing substantially no coloring matter is applied to the image and non-image areas on the recording member, whereby some of the solid colorant attracted to the electrostatic image is charged and migrates to any image portion not developed by the electrostatic developing step.