Patents Assigned to Tokico Ltd.
  • Patent number: 6189659
    Abstract: A disk brake in which a cylinder bore of a caliper is decentered toward the exit side in the rotational direction of a disk with respect to friction pads, and claw portions of the caliper are also decentered toward the exit side with respect to the friction pads. The entrance-side and exit-side claw portions have approximately the same wall thickness in the circumferential direction of the disk. When the brake is activated, the claw portions exhibit approximately the same rigidity so that the surface pressure of each claw portion pressing the outer friction pad can is kept uniform, and non-uniform.
    Type: Grant
    Filed: October 8, 1998
    Date of Patent: February 20, 2001
    Assignees: Tokico Ltd., Nissan Motor Co., Ltd.
    Inventors: Kazuhiro Doi, Tadashi Tamasho, Shinji Suzuki
  • Patent number: 6186289
    Abstract: A disc brake includes a carrier with an inner beam secured to a knuckle, a pair of in board and outboard brake pad assemblies located on opposite sides of a rotor and slideably supported on the carrier, and a caliper extending over the periphery of the rotor and axially moved to urge the in board and outboard brake pad assemblies into frictional engagement with the opposite sides of the rotor. The carrier is constructed so that the difference in natural frequency between a bending mode and a torsion mode is at least 300 Hz. The carrier has a moment of inertia of area/polar moment of inertia of area ratio of at least 0.75.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: February 13, 2001
    Assignee: Tokico Ltd.
    Inventors: Atsushi Takano, Youichi Kumemura, Hideaki Ishii
  • Patent number: 6182805
    Abstract: The flow of a hydraulic fluid caused by sliding movement of a piston is controlled through a sub-disk valve, a main disk valve and a disk valve to generate damping force. A coil is energized to urge a plunger in the valve closing direction against spring force from a spring, thereby adjusting the relief pressure of the disk valve and thus controlling the damping force. The pressure in a back-pressure chamber varies according to the relief pressure of the disk valve. Thus, the valve opening pressure of the main disk valve is also adjusted. An abrupt input is absorbed by relieving the pressure from the back-pressure chamber by deflection of the disk valve. Because “soft” damping force characteristics, which are often used, are maintained with a small electric current, the power consumption can be reduced.
    Type: Grant
    Filed: June 25, 1999
    Date of Patent: February 6, 2001
    Assignee: Tokico Ltd.
    Inventors: Akira Kashiwagi, Nobuyuki Ichimaru, Akinori Kurusu
  • Patent number: 6176494
    Abstract: When a road surface is judged to be undulating and rough, a parameter for a bad road to attain “soft” damping force characteristics is set with priority to setting of a parameter for an undulating road to attain “hard” damping force characteristics. Consequently, “soft” damping force characteristics are obtained to improve the ride quality. This order of the priority is adopted especially when a vehicle speed is low. When the vehicle speed is high, the order of the priority is reversed.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: January 23, 2001
    Assignee: Tokico, Ltd.
    Inventors: Nobuyuki Ichimaru, Masaaki Uchiyama
  • Patent number: 6173960
    Abstract: There is provided a seal apparatus for sealing against a rod, comprising a double seal including a rod seal and an O-ring which serves as a back-up ring for the rod seal. The double seal is provided in an annular groove formed on an inner circumferential surface of a rod guide which guides a sliding motion of the rod. An annular partition wall extends from the rod guide so that a force applied to the rod seal from the O-ring is shared between the rod seal and the partition wall. An annular protrusion is formed on a front end surface of the partition wall, so that when the rod seal is pressed with a large force toward the low-pressure side, the protrusion bites into a stepped surface of the rod seal and a front end surface of the rod seal is brought into contact with a low-pressure-side seal-bearing surface of the rod guide. The force applied to the rod seal is distributed to two sites.
    Type: Grant
    Filed: May 27, 1999
    Date of Patent: January 16, 2001
    Assignee: Tokico Ltd.
    Inventors: Yasuo Inose, Hiromi Machida
  • Patent number: 6158746
    Abstract: In the suspension control apparatus of the present invention, when a lateral acceleration differential value falls outside a lateral acceleration differential value range, a controller calculates a control input for an actuator, based on the lateral acceleration differential value, in preference to a lateral acceleration. Therefore, immediately after the start of rolling of a vehicle and just prior to the end of the rolling when the lateral acceleration differential value falls outside the lateral acceleration differential value range, the control input for the actuator is calculated based on the lateral acceleration differential value.
    Type: Grant
    Filed: March 22, 1999
    Date of Patent: December 12, 2000
    Assignee: Tokico, Ltd.
    Inventors: Masaaki Uchiyama, Nobuyuki Ichimaru
  • Patent number: 6155391
    Abstract: A hydraulic shock absorber of a damping force adjustable type generates a damping force by controlling the flow of an oily fluid caused to occur by the slidable movement of the piston in the cylinder by means of a subsidiary disc valve, a main disc valve and a disc valve mounted on the plunger. The damping force is controlled directly regardless of the piston speed by controlling the relief pressure of the disc valve in accordance with an electric current applied to a coil. The pressure in a back pressure chamber is varied with the relief pressure of the disc valve and the pressure for opening the main disc valve is controlled, thereby extending the scope of controlling the damping force. Further, an excessive rise in the damping force can be controlled due to a rapid input, and an impact can be absorbed by allowing the disc valve to bend and relieving oily fluid in the back pressure chamber.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: December 5, 2000
    Assignee: Tokico Ltd.
    Inventors: Akira Kashiwagi, Takashi Nezu
  • Patent number: 6147498
    Abstract: A device for detecting a fault in a solenoid valve prevents a feeding system from supplying a drive current to a solenoid valve coil which actuates the solenoid valve from being damaged at the time of detection of the fault. The feeding system is provided with a first switch installed between one end of the solenoid valve coil and a battery, a second switch installed between the other end of the solenoid valve coil and a ground, and a plurality of wires for connecting the battery, the first and second switches and the solenoid valve coil. A test power supply system is connected to one end or the other end of the solenoid valve coil and supplies a micro test current to the solenoid valve coil when a current from the battery to the solenoid valve coil is cut off.
    Type: Grant
    Filed: February 18, 1998
    Date of Patent: November 14, 2000
    Assignee: Tokico Ltd.
    Inventors: Osamu Sumiya, Toshio Takayama, Kazumoto Sano
  • Patent number: 6119829
    Abstract: A hydraulic shock absorber includes disc valves seated on valve seats, and annular retainer discs having a diameter less than that of the valve seat. The retainer discs are guided by spacers and axially separable from the disc valves. Annular seal discs are disposed downstream of the disc valves. The inner periphery of the seal discs is partly overlapped with the outer periphery of the retainer discs. The outer peripheral edge of the retainer discs is in substantially linear contact with the disc valves. This arrangement restricts frictional resistance between the disc valves and the retainer discs when the disc valves are flexed and opened.
    Type: Grant
    Filed: September 23, 1998
    Date of Patent: September 19, 2000
    Assignee: Tokico Ltd.
    Inventor: Takao Nakadate
  • Patent number: 6112864
    Abstract: A pin slide mechanism 3 comprises a pair of support portions 23, 24 on a carrier 1 secured to a non-rotating portion of a vehicle. A support portion 24 provided on a tip end of an arm 28 extends from the carrier 1 inwardly of the vehicle. By slidably fitting a cylindrical portion 27 provided on a caliper body 2 via a sleeve 26 onto a pin portion 25a of a pin/bolt 25, the caliper body 2 is secured to the support portions 23, 24. The caliper has an increased weight by containing an electrically-driven device therein, and is supported by the support portions 23, 24 in a straddle-mounted fashion to prevent inclination of the caliper during braking.
    Type: Grant
    Filed: March 22, 1999
    Date of Patent: September 5, 2000
    Assignee: Tokico Ltd.
    Inventors: Shinji Suzuki, Tadaaki Nakamura
  • Patent number: 6092816
    Abstract: A cylinder 3 is fitted with a piston 5. A pump rod 12 is fitted into a pump tube 11 in a piston rod 6 to form a pump chamber 13. An oil tank 17 is connected to the pump chamber 13 by a line 16 through a switching valve mechanism 18. An accumulator tank 20 is connected to the cylinder 3 by a line 19 through a switching valve 21. Normally, the switching valve 21 is closed, and a switching valve 26 is set to a position (a) in which the fluid flows to the pump chamber through a check value 27. By using the pump chamber 13 and check valves 23 and 27, a hydraulic fluid is supplied from the oil tank 17 to the accumulator tank 20 by the extension and contraction of the piston rod 6, thereby accumulating the pressurized hydraulic fluid in the accumulator tank 20. By opening the switching valve 21, the cylinder 3 is pressurized to raise the vehicle height.
    Type: Grant
    Filed: April 10, 1998
    Date of Patent: July 25, 2000
    Assignee: Tokico Ltd
    Inventors: Chigaya Sekine, Tetuo Katoh, Kenichi Nakamura
  • Patent number: 6079793
    Abstract: A brake control system includes a master cylinder for developing a brake fluid pressure in response to brake pedal displacement, wheel cylinders mounted to front and rear wheels and adapted to develop a braking force, an actuator for feeding the brake fluid pressure to the respective wheel cylinders, and a controller adapted to enable the actuator to provide a controlled brake fluid pressure to the respective wheel cylinders. Two switch valves are adapted to normally prevent fluid communication between the master cylinder and the wheel cylinders and in the event of a system failure, permit fluid communication between the master cylinder and the wheel cylinders and prevent fluid communication between the actuator and the wheel cylinders. The switch valves are mounted solely to the wheel cylinders of the front wheels.
    Type: Grant
    Filed: October 10, 1997
    Date of Patent: June 27, 2000
    Assignee: Tokico Ltd.
    Inventors: Toshio Takayama, Kunihiro Matsunaga
  • Patent number: 6079526
    Abstract: A damping force control type hydraulic shock absorber is provided having a broad damping force control range and is capable of obtaining appropriate damping force over the entire piston speed range from a low speed region to a high speed region. A piston is fitted in a cylinder, and a reservoir is connected to the cylinder. A cylinder upper chamber and the reservoir are communicated through a main passage in which a main damping valve is provided. The cylinder upper and lower chambers are communicated through an extension sub-passage in which an extension sub-damping valve and an extension variable orifice are provided. The cylinder lower chamber and the reservoir are communicated through a compression sub-passage in which a compression sub-damping valve and a compression variable orifice are provided.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: June 27, 2000
    Assignee: Tokico Ltd.
    Inventors: Takashi Nezu, Akira Kashiwagi, Takao Nakadate
  • Patent number: 6074177
    Abstract: The present invention provides an air compressor which includes an air drier filled with a drying agent and having a first passage for supplying compressed air to one air supplied part while absorbing moisture from the compressed air by passing the compressed air through the drying agent (27) and a second passage (28a) for supplying the compressed air to another air supplied part without passing the compressed air through the drying agent. The air supplied through the first passage returns through the same passage to dry the drying agent.
    Type: Grant
    Filed: March 16, 1999
    Date of Patent: June 13, 2000
    Assignee: Tokico Ltd.
    Inventors: Kan Kobayashi, Takashi Onuma
  • Patent number: 6067490
    Abstract: In the suspension control apparatus of the present invention utilizing a PWM type proportional solenoid valve, in which a current in a form such that a dithering current is superimposed on a target current is applied to a solenoid, when the average intensity of the applied current falls outside a predetermined range, a ratio between a time period during which the PWM signal having a decrease duty ratio is applied and a time period during which the PWM signal having an increase duty ratio is applied is changed so that an amplitude of the dithering current can be maintained at a predetermined level. Therefore, an undesirable increase in hysteresis with respect to a damping force can be suppressed, to thereby ensure good reponsivity for controlling a damping force, regardless of the average intensity of the applied current.
    Type: Grant
    Filed: February 25, 1998
    Date of Patent: May 23, 2000
    Assignee: Tokico, Ltd.
    Inventors: Nobuyuki Ichimaru, Tohma Yamaguchi
  • Patent number: 6058340
    Abstract: A suspension control apparatus includes a variable damping coefficient type shock absorber disposed between sprung mass and unsprung mass of a vehicle and an actuator for setting and adjusting a damping coefficient of the variable damping coefficient type shock absorber on the basis of a control signal. An upward and downward absolute velocity detector for detecting an upward absolute velocity and a downward absolute velocity of the vehicle is provided. A control unit changes a signal from the upward and downward absolute velocity detector in accordance with a running condition of the vehicle to obtain a control target signal. A control signal generator outputs the control signal for the actuator on the basis of the control target signal from the control unit.
    Type: Grant
    Filed: December 22, 1994
    Date of Patent: May 2, 2000
    Assignee: Tokico Ltd.
    Inventors: Masaaki Uchiyama, Taro Uyama, Yoshiko Matsumura, Nobuyuki Ichimaru
  • Patent number: 6047795
    Abstract: A disk brake mounting member having a pair of left and right arms spaced apart from each other in the circumferential direction of a disk. A pair of left and right pin holes are formed in the left and right arms, respectively, with different bore diameters. The pin holes are fitted with sliding pins, respectively, which support a caliper slidably in the axial direction of the disk. The arms are previously provided with left and right projections near the respective open ends of the pin holes so as to be in symmetry with each other. At least one of the projections is formed into a shape different from that of the other when the pin holes are formed in the arms by machining. Also disclosed is a method of producing the disk brake mounting member. According to this method, a mounting member is first cast to have left and right projections. One of the projections is then cut off.
    Type: Grant
    Filed: May 19, 1997
    Date of Patent: April 11, 2000
    Assignee: Tokico Ltd.
    Inventors: Kinzo Kobayashi, Yukio Tanaka, Shinji Suzuki, Kouichi Masuko
  • Patent number: 6035636
    Abstract: In the master cylinder of the present invention, a cylindrical portion of a grommet seal includes at least two outer sealing projections on an outer circumferential surface thereof, an inner sealing projection on an inner circumferential surface thereof at a position corresponding to a recess between the outer sealing projections, and an abutting portion adapted to abut against a positioning stepped portion provided in a supply fitting of a reservoir. When the supply fitting is inserted into the grommet seal fitted in a boss of a cylinder body, deformation of the inner sealing projection is relieved by a cavity constituted by the recess between the outer sealing projections. When a hydraulic pressure is applied to the cylindrical portion of the grommet seal, because the abutting portion of the grommet seal abuts against the positioning stepped portion of the supply fitting of the reservoir, the cylindrical portion is axially compressed, so that sealability of the sealing projections can be improved.
    Type: Grant
    Filed: March 16, 1998
    Date of Patent: March 14, 2000
    Assignee: Tokico Ltd.
    Inventors: Takato Ogiwara, Kenji Sano
  • Patent number: 5996748
    Abstract: A piston is slidably fitted in a cylinder for dividing the interior of the cylinder into upper and lower cylinder chambers. A reservoir is connected to the piston. A primary passage communicates between the upper cylinder chamber and the reservoir. The primary passage includes a primary damping valve. A secondary passage is connected to the primary passage to bypass the primary damping valve. A constant orifice, a filter, and a damping force adjusting valve are provided in the secondary passage. The primary damping valve includes a pilot line. The pilot line is connected downstream of the filter. The flow resistance of the damping force adjusting valve is directly adjusted by changing the cross sectional flow area of the damping force adjusting valve. The valve opening pressure of the primary damping valve is adjusted by changing the pilot pressure introduced from the pilot line. When the filter becomes clogged, the primary passage ensures the flow of the hydraulic fluid.
    Type: Grant
    Filed: March 12, 1997
    Date of Patent: December 7, 1999
    Assignee: Tokico Ltd.
    Inventors: Takashi Nezu, Akira Kashiwagi
  • Patent number: 5997106
    Abstract: A brake fluid pressure control system includes an external source of fluid pressure, a wheel cylinder, and a fluid pressure control valve disposed between the external source of fluid pressure and the wheel cylinder. A controller is operable to control the fluid pressure control valve whereby fluid pressure under control is fed from the external source of fluid pressure to the wheel cylinder. When a change in pressure within the wheel cylinder occurs, a fail safe valve is operable to disconnect the wheel cylinder from the fluid pressure control valve and instead, connect the wheel cylinder to a master cylinder. Inspection of the fail safe valve is carried out by disconnecting the wheel cylinder from the control valve when no brake is applied, feeding fluid pressure from the external source of fluid pressure to the wheel cylinder, and detecting a change in pressure within the wheel cylinder. An alert device is provided to give a warning in the event of a system failure.
    Type: Grant
    Filed: October 8, 1997
    Date of Patent: December 7, 1999
    Assignee: Tokico Ltd.
    Inventor: Toshio Takayama