Patents by Inventor Kenji Shirai

Kenji Shirai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4986613
    Abstract: A hydraulic braking system for an automotive vehicle having a power source for generating a hydraulic power pressure, a reservoir, a master cylinder, a hydraulic booster for actuating the master cylinder in response to depression of a brake pedal and a plurality of wheel brake cylinders for braking respective road wheels, which are divided into a first group of wheel brake cylinders communicating with the master cylinder and a second group of wheel brake cylinders communicating with the hydraulic booster. An auxiliary cylinder is disposed between the master cylinder and the first group of wheel brake cylinders to which a hydraulic braking pressure from the master cylinder is directly applied in its inoperative condition, and it increases the hydraulic braking pressure in response to depression of the brake pedal in its operative condition which is made when the hydraulic power pressure, for example, is less than the hydraulic braking pressure by a predetermined difference.
    Type: Grant
    Filed: July 28, 1989
    Date of Patent: January 22, 1991
    Assignees: Aisin Seiki Kabushiki Kaisha, Toyota Jidosha Kabushiki Kaisha
    Inventors: Michiharu Nishii, Genji Mizuno, Yoshihisa Nomura, Masahiko Kato, Kenji Shirai, Junichi Tanoue
  • Patent number: 4887869
    Abstract: A pair of spaced apart large-diameter and small-diameter lands between which a fluid chamber is defined are formed on a second piston in a tandem cylinder to which an anti-skid device is added. Booster pressure is applied to the fluid chamber to act on the large-diameter land in a manner fluidly locking the second piston against movement despite a reduction in pressure in the first and second pressure chambers during operation of the anti-skid device. As a result, the movement of the brake pedal in the normal direction of depression is prevented when the anti-skid devices operates.
    Type: Grant
    Filed: October 19, 1988
    Date of Patent: December 19, 1989
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Michiharu Nishii, Genji Mizuno, Yoshihiko Tada, Yoshihisa Nomura, Masahiko Kato, Kenji Shirai, Junichi Tanoue
  • Patent number: 4876853
    Abstract: A tandem master cylinder with a booster used for a hydraulic actuator such as an automotive brake system. The master cylinder has a first and a second independently movable presser piston disposed in tandem in a first housing such that the presser pistons and the first housing define a first and a second pressure chamber. The booster has a first power piston advanced by a fluid pressure in a first power chamber formed in a second housing, to advance the first presser piston. The booster has a valve operable due to a relative movement between the first power piston, and an operating member for operating said booster, whereby the fluid pressure in the first power chamber is controlled according to an operating force applied to the operating member.
    Type: Grant
    Filed: February 5, 1987
    Date of Patent: October 31, 1989
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kenji Shirai, Yoshihisa Nomura
  • Patent number: 4848853
    Abstract: A hydraulic brake system includes a master cylinder for generating a brake fluid pressure in response to a brake pedal, a power fluid source for generating a power fluid pressure by increasing a brake fluid to a predetermined pressure. A dynamic fluid pressure control apparatus supplies the brake fluid pressure to regulate the power fluid pressure from the power fluid pressure source in response to the brake pedal. A plurality of wheel cylinders of each wheel for the vehicle are fluidically communicated with a dynamic fluid pressure control apparatus and the master cylinder via a fluid passage separated into plural control systems.
    Type: Grant
    Filed: October 19, 1988
    Date of Patent: July 18, 1989
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Genji Mizuno, Michiharu Nishii, Yoshihiko Tada, Yoshihisa Nomura, Masahiko Kato, Kenji Shirai, Junichi Tanoue
  • Patent number: 4812777
    Abstract: A manually/electrically operated brake system for applying a brake to a wheel of a vehicle, including a master cylinder operated by a brake operating member, to generate a manually controlled braking pressure according to an operation of the brake operating member, a wheel brake cylinder for applying a brake to the wheel, a primary fluid passage for connecting the master cylinder to the wheel brake cylinder, an electrically controlled pressure generating device for generating an electrically controlled braking pressure to produce a required braking effect determined based on at least one of an operating force and an operating stroke of the brake operating member, and a switching device provided in the primary fluid passage, for applying the electrically controlled braking pressure to the wheel brake cylinder while disconnecting the master cylinder from the wheel brake cylinder when the electrically controlled pressure generating device is normally functioning, and for applying the manually controlled braking
    Type: Grant
    Filed: July 8, 1987
    Date of Patent: March 14, 1989
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Kenji Shirai
  • Patent number: 4800724
    Abstract: This brake booster is for a vehicle whose tandem type brake master cylinder has a first piston and a second piston operating in tandem, with first and second pressure chamber and a reservoir chamber for the second brake fluid supply pressure chamber being defined in it. The brake booster has a power piston, one side of which is presented to an actuating pressure chamber, and which is driven by supply of pressurized brake fluid to that actuating pressure chamber so as to push the first piston of the master cylinder so as to expel fluid from the first and second pressure chambers towards the vehicle brakes. Brake fluid is supplied by a valve to the booster actuating pressure chamber upon brake pedal depression. A conduit is provided for directly conducting fluid from the actuating pressure chamber of the brake booster to the reservoir chamber for the second pressure chamber of the master cylinder.
    Type: Grant
    Filed: December 29, 1986
    Date of Patent: January 31, 1989
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Makoto Asahara, Kenji Shirai
  • Patent number: 4773224
    Abstract: In this portless type master cylinder device, a cylinder bore is formed in a body thereof, and a piston member is fitted in the cylinder bore and is slidably movable from an initial axial position therein and defines a pressure chamber in cooperation with the cylinder bore. An intake valve communicates between the cylinder chamber and the fluid reservoir via a fluid flow path, and is opened when the piston member is in its initial axial position while it is closed when the piston member moves through more than a determinate relatively small axial distance from its initial axial position.
    Type: Grant
    Filed: October 15, 1986
    Date of Patent: September 27, 1988
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Shigeru Sakamoto, Kenji Shirai, Haruo Sugimoto, Masaaki Okuyama
  • Patent number: 4736768
    Abstract: A relief valve used for hydraulic devices such as the master cylinder for motor vehicles, comprising a housing for passing hydraulic fluid therethrough to adjust the hydraulic pressure, a ball valve disposed in the housing, a coil spring for pushing the ball valve in the housing and plural finger-like portions formed in the inside of the housing to resiliently nip the ball valve so as to prevent the vibration of ball valve in the direction of diameter of the housing at the time of releasing hydraulic fluid through the inside of the housing, thereby making it possible to avoid the generation of strange noise by the vibration of ball valve. It is desirable to form the surface of valve body or the valve body side surface of the finger-like portions so that it has a surface roughness within a specific range in order to make the noise prevention effect more perfect.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: April 12, 1988
    Assignees: Aisin Seiki Kabushiki Kaisha, Toyota Jidosha Kabushiki Kaisha
    Inventors: Kaoru Tsubouchi, Kaoru Nakamura, Chiaki Ochiai, Genji Mizuno, Kenji Shirai, Shigeru Sakamoto
  • Patent number: 4421362
    Abstract: In an anti-skid brake control system incorporated with dual hydraulic braking circuits for independently controlling respective braking fluids supplied to the right and left rear-wheel brake cylinders from a tandem master cylinder, an electronic anti-skid brake control apparatus is incorporated with one of the hydraulic braking circuits for decreasing the pressure applied to one of the rear-wheel brake cylinders from the master cylinder in response to an electric signal indicative of a predetermined wheel locking condition, and a modulator valve assembly is incorporated with the other hydraulic braking circuit to cooperate with the anti-skid brake control apparatus so as to control the pressure applied to the other rear-wheel brake cylinder in response to activation of the anti-skid brake control apparatus.
    Type: Grant
    Filed: October 29, 1981
    Date of Patent: December 20, 1983
    Assignee: Toyota Jidosha Kogyo Kabushiki Kaisha
    Inventors: Kenji Shirai, Fumio Nakagawa
  • Patent number: 4333550
    Abstract: A disc brake comprises a disc rotor, a pair of braking pad assemblies consisting of a friction pad and a backing plate, a transmitting member for transmitting urging force from an actuator to the braking pad assembly, a stopper for limiting the movement amount of the braking pad assembly in the rotational direction of the disc rotor, and a pad return spring. The total thickness of the backing plate plus the transmitting member is made variable through a slant surface made on both members respectively in a complementary contacting state.
    Type: Grant
    Filed: May 20, 1980
    Date of Patent: June 8, 1982
    Assignee: Toyota Jidosha Kogyo Kabushiki Kaisha
    Inventor: Kenji Shirai
  • Patent number: 4314216
    Abstract: A mechanical filter having at least a pair of mechanical vibrators which are arrayed approximately in parallel with each other in regard to their longitudinal axes, and two couplers which are coupled to the pair of mechanical vibrators. According to the mechanical filter one of the pair of mechanical vibrators undergoes the vibration of the order of an odd number and the other one undergoes the vibration of the order of an even number in the same vibration mode, or both of them undergo the vibration of the order of an odd number or even number in the same vibration mode. Furthermore, these mechanical vibrators have such a mechanical size that they will vibrate at their required order of vibration and at their respective resonance frequencies, and the two couplers are so constructed that they will be differentially coupled to the pair of mechanical vibrators approximately at right angles therewith.
    Type: Grant
    Filed: November 9, 1979
    Date of Patent: February 2, 1982
    Assignee: Fujitsu Limited
    Inventors: Takashi Gounji, Yoshihiko Kasai, Kenji Shirai
  • Patent number: 4299311
    Abstract: A disc brake comprises a rotatable brake disc, and a pad assembly disposed in opposed relation to the pressure bearing surface of the brake disc. The pressure bearing surface of the brake disc is inclined diametrically thereof, and the pad assembly is adapted to displace diametrically of the brake disc so as to engage the pressure bearing surface of the brake disc, whereby there is provided a clearance between the press surface of the pad assembly and the brake disc, which clearance is large enough to prevent the dragging phenomenon.
    Type: Grant
    Filed: November 23, 1979
    Date of Patent: November 10, 1981
    Assignee: Toyota Jidosha Kogyo Kabushiki Kaisha
    Inventors: Kenji Shirai, Minoru Takeuchi
  • Patent number: 4289216
    Abstract: A disc brake free from dragging torque while being in non-braking state. In this brake, a gap between the friction surface of a rotary disc and the acting surface of an actuator for urging a braking pad assembly onto the disc is made progressively larger into a wedge shape toward the axis of the disc. The torque receiving surface of a torque receiving member is made so slant as to produce a component for moving the pad assembly in a direction away from the axis of the disc in a wedging manner into the gap. The pad assembly is of corresponding shape to the above-mentioned gap and the torque receiving surface.
    Type: Grant
    Filed: February 12, 1980
    Date of Patent: September 15, 1981
    Assignee: Toyota Jidosha Kogyo Kabushiki
    Inventors: Kenji Shirai, Hidetoshi Shimizu, Junichi Tanoue