Patents Assigned to Tokico Ltd.
  • Patent number: 5975258
    Abstract: A damping force control type hydraulic shock absorber of the present invention includes a cylindrical valve member. One end of the cylinder valve member is closed. Also, the shock absorber includes annular inner and outer seal portions, and a valve seat provided there-between, all of which project from an inner wall of a bottom portion of the valve member and are concentric with one another. A disk valve is secured at an inner peripheral portion thereof to the inner seal portion and abuts at an outer peripheral portion thereof on the valve seat. A retainer disk stacks on the disk valve. An annular seal ring abuts at an inner peripheral portion thereof of an outer peripheral edge portion of the retainer disk, and is secured at an outer peripheral portion thereof to the outer seal portion. A blocking member is connected to an open end of the valve member so that a pilot chamber is formed by the retainer disk, the seal ring and the blocking member.
    Type: Grant
    Filed: November 7, 1997
    Date of Patent: November 2, 1999
    Assignee: Tokico, Ltd
    Inventors: Takashi Nezu, Naoki Makita
  • Patent number: 5975252
    Abstract: Two shim plates provided for a friction pad are arranged to be slidable relative to each other in the circumferential direction of a disk, thereby suppressing the transmission of rotational force from the disk to a caliper through the friction pad and so forth during a braking operation. A friction pad including a lining and a backing plate is disposed between the disk and an outer leg portion of the caliper. An inner shim plate is integrally mounted on the back of the backing plate. An outer shim plate is disposed between the inner shim plate and the outer leg portion of the caliper in such a manner as to be slidable relative to the inner shim plate in the circumferential direction of the disk. During a braking operation, when the friction pad pressed by the caliper is circumferentially displaced by being dragged by the disk, the inner shim plate, together with the friction pad, slides relative to the outer shim plate, thereby reducing rotational force transmitted from the disk to the caliper.
    Type: Grant
    Filed: May 15, 1998
    Date of Patent: November 2, 1999
    Assignees: Tokico, Ltd., Nissan Motor Co., Ltd.
    Inventors: Shinji Suzuki, Hideaki Ishi, Kazuhiro Doi, Tadashi Tamasho
  • Patent number: 5968102
    Abstract: The present invention provides a suspension control apparatus which can perform good suspension control regardless of change in temperature. The suspension control apparatus comprises a transistor capable of being turned ON/OFF in response to a level of a PWM signal, a current sensor for detecting current flowing through a proportional solenoid, and a controller for adjusting a duty ratio of the PWM signal on the basis of the comparison between a current data detected by the current detecting means and a previously set reference data to correct command current. The current actually flowing through the proportional solenoid is measured, and the duty ratio of the PWM signal is adjusted to obtain a desired damping force on the basis of the measured current. With this arrangement, if a temperature of the proportional solenoid is increased to increase resistance thereof due to application of current to the proportional solenoid, the applied current is corrected to provide the desired damping force.
    Type: Grant
    Filed: March 14, 1997
    Date of Patent: October 19, 1999
    Assignee: Tokico Ltd.
    Inventors: Nobuyuki Ichimaru, Hiroshi Sakai, Masaaki Uchiyama
  • Patent number: 5960915
    Abstract: The present invention provides a hydraulic shock absorber in which a damping force can be changed nearly linearly as a valve body driven by a proportional solenoid is displaced, by utilizing ports and a oil groove which can easily be formed by a conventional machine tool such as a drilling machine or a lathe. Oil passages and an annular groove connected to the oil passages are formed in a surface of a cylindrical guide portion along which a plunger can slide, and, circular oil passages and an annular groove connected to and offset from the oil passages are formed in a surface of a plunger. The oil passages and annular groove in the plunger can easily be formed by a conventional machine tool such as a drilling machine or a lathe. When an oil path is opened, the oil passages are firstly opened and then the associated annular groove is opened. Thus, a damping force can be changed nearly linearly, and response to the switching of the damping force can be improved.
    Type: Grant
    Filed: August 7, 1997
    Date of Patent: October 5, 1999
    Assignee: Tokico, Ltd.
    Inventors: Takashi Nezu, Akira Kashiwagi
  • Patent number: 5954163
    Abstract: In the disk brake of the present invention, each arm of the carrier has a projecting pad guide, and each friction pad has recesses fitted onto the pad guides of the carrier. Each pad spring has integrally formed therewith a generally U-shaped guide plate which is bent along the pad guide and resiliently engaged with and presses against the pad guide to thereby mount the pad spring on the arm of the carrier. Each recess of the friction pads includes a groove at a position corresponding to at least one bent portion of the guide plate, which is separated from a corner portion of the pad guide and deformed into a projection toward the recess.
    Type: Grant
    Filed: September 25, 1997
    Date of Patent: September 21, 1999
    Assignee: Tokico Ltd.
    Inventors: Shinji Suzuki, Takahiro Tokunaga
  • Patent number: 5951116
    Abstract: A plurality of electrical fluid pressure control valves or a plurality of groups each comprised of a plurality of electrical fluid pressure control valves are operatively associated with respective power supply replays. The electrical fluid pressure control valves and a plurality of electrical switch valves are connected in parallel to a power source. A plurality of failure sensors are associated with the respective electrical fluid pressure control valves or the respective groups so as to detect whether an electrical system failure in any one of the electrical fluid pressure control valves or the groups occurs. If occurs, failure control unit is operable to control a corresponding one of the power supply relays so as to cause a corresponding one of the electrical switch valves to selectively connect a corresponding one of the wheel cylinders to a master cylinder.
    Type: Grant
    Filed: February 10, 1998
    Date of Patent: September 14, 1999
    Assignee: Tokico Ltd.
    Inventors: Mitsuhiro Nagasaka, Toshio Takayama
  • Patent number: 5950482
    Abstract: A tubular member to be shaped comprises a first portion to be shaped and a second portion other than the first portion. A punch having a projection is inserted into the tubular member and the tubular member is pressed between a die having a recess and an anvil within a range where elastic deformation of the second portion occurs, to thereby form the first portion into an outwardly projecting portion. When the first portion is to be formed into an inwardly projecting portion, a die having a recess is inserted into the tubular member and the tubular member is pressed between a punch having a projection and an anvil within a range where elastic deformation of the second portion occurs, to thereby form the first portion into the inwardly projecting portion.
    Type: Grant
    Filed: March 12, 1998
    Date of Patent: September 14, 1999
    Assignee: Tokico, Ltd.
    Inventors: Junichi Nagasawa, Makoto Kitamura, Yuichi Kobayashi, Osamu Kato
  • Patent number: 5949683
    Abstract: A robot control apparatus does not require an expert to perform programming, prepare teaching data or reprogram the motions of a work robot. The controller for the robot accepts the teaching point instructed by a beginner operator, and computes the start and end points in a track from the input teaching points. The controller also computes target start and end points in each of the passes in the track based on the current track points and the overspray width input by the operator and automatically allows for the overspray width. The control apparatus therefore facilitates operation of painting tasks which conventionally required a labor-intensive effort in reprogramming by an expert operator.
    Type: Grant
    Filed: December 19, 1995
    Date of Patent: September 7, 1999
    Assignee: Tokico Ltd.
    Inventors: Yusuke Akami, Noriaki Saisaka, Tatsuya Rembutsu
  • Patent number: 5947233
    Abstract: A disc brake includes a carrier with a pair of axially and outwardly extending arms. A pair of pad springs are mounted to the inner side of the arms. Each of the pad springs has a pair of return springs. The return springs extend radially of a rotor and have respective projections. Each of the return spring is made by bending an elongated tongue. A pair of backing plates are attached to a corresponding pair of friction pads and have lugs. A wear warning element is attached adjacent to the lug of each backing plate and has a bent portion. Each of the projections is resiliently in contact with the inner side of the bent portion so as to constantly urge the backing plate and the friction pad in a direction away from the rotor.
    Type: Grant
    Filed: July 7, 1997
    Date of Patent: September 7, 1999
    Assignees: Tokico Ltd., Nissan Motor Co., Ltd.
    Inventors: Kinzo Kobayashi, Naganori Koshimizu, Kazuhiro Doi, Tadashi Tamasho, Tomihiro Suenaga
  • Patent number: 5943937
    Abstract: A pressure differential operated brake booster includes a housing, a diaphragm assembly adapted to divide the interior of the housing into a constant pressure chamber and a variable pressure chamber, a valve body carried by the diaphragm assembly, a valve mechanism arranged within the valve body and including a plunger connected to an input rod, and a reaction assembly disposed between the plunger and an output rod. The valve mechanism is operable to develop a pressure differential across the diaphragm assembly to transmit its movement to the output rod and feed part of the resulting reaction force back to the input rod through the reaction assembly and the plunger. The reaction assembly includes a front reaction disk and a separate rear reaction disk having a diameter less than that of the front reaction disk and greater than that of the plunger. The front reaction disk is disposed between the valve body and the output rod. The valve body has at its front end a recess to receive the rear reaction disk.
    Type: Grant
    Filed: May 30, 1997
    Date of Patent: August 31, 1999
    Assignee: Tokico Ltd.
    Inventor: Mitsuhiro Endo
  • Patent number: 5944153
    Abstract: The disclosed suspension control system includes actuators for adjusting damping forces of front and rear variable-damping force shock absorbers. Also provided are front and rear vertical acceleration detecting devices. Usual control for the actuators are performed on the basis of the vertical accelerations detected by the vertical acceleration detecting devices. Control signal adjusting means is provided to adjust a control signal to be sent to the actuator for the rear shock absorber such that the damping force of the rear shock absorber is reduced when the vertical acceleration detected by the front vertical acceleration detecting device or a rate of change thereof exceeds a preset reference value.
    Type: Grant
    Filed: September 29, 1997
    Date of Patent: August 31, 1999
    Assignee: Tokico Ltd.
    Inventor: Nobuyuki Ichimaru
  • Patent number: 5941508
    Abstract: A hydraulic shock absorber including a cylinder having a hydraulic fluid sealed therein, a reservoir connected to the cylinder so that a pressure is always transmitted between the cylinder and the reservoir and a self-pumping mechanism provided between the cylinder and an oil tank to effect feeding and discharge of the hydraulic fluid between the oil tank and the cylinder by extension and contraction of a piston rod, to thereby control a length of extension of the piston rod. The cylinder is connected to a pressure accumulating mechanism having a pressure accumulating tank and a switching valve mechanism. The switching valve mechanism is adapted to be switched to accumulate a pressure in the pressure accumulating tank or apply a pressure accumulated in the pressure accumulating tank to the cylinder.
    Type: Grant
    Filed: May 21, 1997
    Date of Patent: August 24, 1999
    Assignee: Tokico Ltd.
    Inventors: Hiroshi Murata, Chigaya Sekine
  • Patent number: 5934890
    Abstract: Joint guides comprise mutually opposing guide portions formed on a casing and mutually opposing guide portions provided on an orbiting scroll member. A plate spring is integrally attached to a part of each guide portion. Even when a load due to rotational torque from the orbiting scroll member acts on each slider from a loading-side guide portion, resilient force from the plate spring presses a sliding surface of the slider toward a sliding surface of the loading-side guide portion, thereby preventing the formation of a gap between the sliding surface of each slider and a convexly curved portion of the associated plate spring or between the sliding surface of each slider and the sliding surface of the associated guide portion, and thus preventing the occurrence of a rattle.
    Type: Grant
    Filed: May 20, 1997
    Date of Patent: August 10, 1999
    Assignee: Tokico Ltd.
    Inventors: Hiroyuki Mihara, Kazutaka Suefuji, Toshikazu Harashima, Yuji Komai
  • Patent number: 5934421
    Abstract: In a damping force control type hydraulic shock absorber, the flow path area of a port is changed by moving a spool according to an electric current supplied to an actuator, and thus the flow path area of a passage between cylinder upper and lower chambers is directly changed, thereby controlling orifice characteristics. Moreover, the pressure in a pilot chamber is changed according to the resulting pressure loss so as to change the valve opening pressure of a disk valve, thereby controlling valve characteristics. This enables the damping force characteristic control range to be widened. The pilot chamber is formed by the side wall of a valve member, the disk valve, a seal disk, and a seal member, also, the seal member has no sliding portion. It is therefore possible to minimize the leakage of hydraulic fluid and to obtain stable damping force characteristics. It is also possible to minimize variations in damping force with temperature changes.
    Type: Grant
    Filed: December 11, 1996
    Date of Patent: August 10, 1999
    Assignee: Tokico Ltd.
    Inventors: Takao Nakadate, Akira Kashiwagi, Takashi Nezu, Naoki Makita
  • Patent number: 5931451
    Abstract: An air-suspension system having a canister formed such that the inner diameter of an insert portion thereof is smaller than that of a tube mounting portion thereof to form a pressure-receiving portion between the insert and tube mounting portions. In addition, an air piston is formed such that the inner diameter of an insert portion thereof is smaller than that of a tube mounting portion thereof to form a pressure-receiving portion between the insert and tube mounting portions. When the pressure in an air chamber increases, the pressure-receiving portions receive the increased pressure to thereby strongly press the canister against a canister cap and the air piston against an air piston guide.
    Type: Grant
    Filed: March 12, 1997
    Date of Patent: August 3, 1999
    Assignee: Tokico Ltd.
    Inventor: Hirohide Onami
  • Patent number: 5924703
    Abstract: The present invention provides a suspension control apparatus including dither amplitude setting device which is adapted to set the amplitude of the dithering current to be superimposed on the command current is set to a small value in a region in which a damping force generated by the shock absorber changes at a high rate relative to changes in intensity of the current applied to the solenoid. The present invention also provides a suspension control apparatus including dither frequency setting device which is adapted to set the frequency of the dithering current to a high frequency in a region in which a damping force generated by the shock absorber changes at a high rate relative to changes in intensity of the current applied to the solenoid and set the frequency of the dithering current to a low frequency in a region other than the above-mentioned region.
    Type: Grant
    Filed: December 8, 1997
    Date of Patent: July 20, 1999
    Assignee: Tokico Ltd.
    Inventor: Nobuyuki Ichimaru
  • Patent number: 5921281
    Abstract: A fluid passage switching valve includes a core structure provided with an input passage extending from an input port. The input passage opens on an outer peripheral surface of the core structure at such a position that when a plunger is in a fluid cut-off position, the input passage is closed by an inner surface of the plunger, and as the plunger moves toward a fluid passing position, the input passage is opened and communicated with an input port-side fluid chamber. An output port is communicated with an output port-side fluid chamber. The plunger has a communicating bore which provides communication between the input and output port-side fluid chambers. The pressure-receiving area of the plunger in relation to the input port-side fluid chamber is approximately the same as that of the plunger in relation to the output port-side fluid chamber over the entire travel range of the plunger.
    Type: Grant
    Filed: March 17, 1998
    Date of Patent: July 13, 1999
    Assignee: Tokico Ltd.
    Inventors: Toshio Takayama, Kunihiro Matsunaga
  • Patent number: 5921166
    Abstract: A cylinder apparatus including a piston slidably fitted in a cylinder having a hydraulic fluid sealed therein. A piston rod is connected at one end thereof to the piston. The other end portion of the piston rod extends as far as the outside of the cylinder through a seal block fitted to an open end portion of the cylinder. The seal block retains a double seal including a rod seal that is in sliding contact with the piston rod and an O-ring that resiliently biases the rod seal toward the piston rod. The seal block is provided with a projection extending between the O-ring and the rod seal to bear a part of biasing force applied to the rod seal from the O-ring. The projection is provided at a side of the O-ring and rod seal which is remote from the piston.
    Type: Grant
    Filed: April 25, 1997
    Date of Patent: July 13, 1999
    Assignee: Tokico, Ltd.
    Inventors: Hiromi Machida, Tetsuo Katoh, Yasuo Inose, Hiroshi Murata
  • Patent number: 5901820
    Abstract: A piston is slidably fitted in a cylinder for dividing the interior of the cylinder into upper and lower cylinder chambers. The upper cylinder chamber communicates with the lower cylinder chamber through a check valve. The lower cylinder chamber communicates with a reservoir through a check valve. The upper cylinder chamber communicates with the lower cylinder chamber through an extending side damping valve. The lower cylinder chamber communicates with the reservoir through a contracting side damping valve. A piston rod is connected to the piston. When the piston rod is in an extending stroke, a damping force is generated by the extending side damping valve. When the piston rod is in a compressing stroke, a damping force is generated by the contracting side damping valve. The reservoir includes a connecting hole having an opening. A baffle plate is provided within the reservoir and above the opening of the connecting hole.
    Type: Grant
    Filed: January 22, 1997
    Date of Patent: May 11, 1999
    Assignee: Tokico Ltd.
    Inventors: Akira Kashiwagi, Takashi Nezu, Takao Nakadate
  • Patent number: 5901815
    Abstract: A disk brake includes a carrier secured to a fixed part of a vehicle, a rotor fixed to a vehicle wheel, a caliper slidably mounted to the carrier, a pair of inboard and outboard pad assemblies for operative braking coaction with the rotor, and a pair of pad springs adapted to slidably support the inboard and outboard pad assemblies. The carrier includes an inboard member, an outboard member, and a pair of opposite side members each having a pair of opposite guide grooves. The pad springs each include a bridge portion, and a pair of legs depending from opposite ends of the bridge portion. The legs each include a pair of pad guides fit into the guide grooves.
    Type: Grant
    Filed: November 13, 1997
    Date of Patent: May 11, 1999
    Assignee: Tokico Ltd.
    Inventors: Kinzo Kobayashi, Sinji Suzuki, Takahiro Tokunaga