Patents Assigned to Tokico Ltd.
  • Patent number: 6592345
    Abstract: There is provided a scroll compressor comprising: a fixed-side member comprising a casing and a fixed scroll member provided in the casing; a driving shaft rotatably provided in the casing; an orbiting scroll member orbitably provided at a distal end of the driving shaft; a suction opening provided in the fixed-side member; and a discharge opening provided in the fixed-side member. Each of the scroll members includes an end plate and a spiral wrap portion standing on the end plate. The wrap portion of the orbiting scroll member is adapted to overlap the wrap portion of the fixed scroll member so as to define a plurality of compression chambers. The suction opening communicates with the outermost compression chamber, and the discharge opening is adapted to discharge a compressed gas from an inner compression chamber.
    Type: Grant
    Filed: January 30, 2002
    Date of Patent: July 15, 2003
    Assignee: Tokico Ltd.
    Inventors: Kazutaka Suefuji, Hideaki Ikeda, Junichi Ikeda
  • Patent number: 6578360
    Abstract: A master cylinder including a cylinder having one end open to the outside. A secondary piston guide ring, a sleeve and a primary piston guide ring are adapted to be fitted in this order into the cylinder from the one open end. A piston is slidably fitted in an axial direction of the cylinder, into each of the secondary piston guide ring, the sleeve and the primary piston guide ring. A retainer is provided at the open end of the cylinder, and adapted to abut against the primary piston guide ring so as to prevent escape of the primary piston guide ring from the cylinder. An elastic member is provided between a rearward end portion of the sleeve and a forward end portion of the primary piston guide ring.
    Type: Grant
    Filed: October 31, 2001
    Date of Patent: June 17, 2003
    Assignee: Tokico Ltd.
    Inventors: Tomonori Mouri, Takato Ogiwara, Hiromi Ando, Naganori Koshimizu
  • Patent number: 6571921
    Abstract: A motor-driven disk brake is capable of functioning as a parking brake satisfactorily without degrading the brake operating feeling and impairing the function of operating as a motor-driven brake. A stator and rotor of an electric motor are provided in a caliper body floatably supported on a carrier. The rotation of the rotor is transmitted to a piston after being converted into rectilinear motion through a ball-and-ramp mechanism and an adjusting nut. The piston, together with a claw member, presses brake pads against a disk rotor. A rotation assisting device is provided between the rear end of the rotor and a motor casing. A rotary disk constituting the rotation assisting device is rotated through a wire extending from an external operating member.
    Type: Grant
    Filed: May 30, 2001
    Date of Patent: June 3, 2003
    Assignee: Tokico Ltd.
    Inventors: Yukio Ohtani, Tohma Yamaguchi, Takuya Usui
  • Publication number: 20030066719
    Abstract: An electric braking apparatus is disclosed in which a rotational movement from a motor is converted into linear movement that moves a brake piston to generate braking force. The electric brake apparatus can perform full parking brake function without sacrificing its original braking function. In operation, immediately after generation of braking force caused by rotation of the rotor 26, supply of electricity to the motor is turned off. After supply of electricity is turned off, however, the rotor 26 is restricted from returning to its original position due to an engagement with an engaging claw 54 via a claw wheel 50, thereby keeping the barking brake remain effective. When electricity is thereafter supplied to the motor, the rotor 26 generates rotational torque sufficiently strong to push down the engaging claw 54 for disengagement, thereby releasing the parking brake.
    Type: Application
    Filed: July 30, 2002
    Publication date: April 10, 2003
    Applicant: Tokico, Ltd.
    Inventors: Jun Watanabe, Takuya Usui, Hirotaka Oikawa
  • Patent number: 6491140
    Abstract: In an electric disc brake a stator and a rotor of an electric motor are disposed in a caliper body, and a rotation of the rotor is converted into a linear movement by a ball-ramp mechanism. Such linear movement is transmitted to a piston, so that brake pads are urged against a disc rotor by the piston and a pawl member. Two external gears are provided on the rotor and internal gears are provided on two discs of the ball-ramp mechanism so that, due to engagement between the external gears and the internal gears, the two discs of the ball-ramp mechanism are rotated with a given rotational ratio with respect to the rotor to cause differential movement which in turn causes one of the discs to shift, thereby advancing the piston.
    Type: Grant
    Filed: March 15, 2001
    Date of Patent: December 10, 2002
    Assignee: Tokico, Ltd.
    Inventors: Takuya Usui, Yukio Ohtani
  • Patent number: 6474454
    Abstract: A pilot chamber is formed at the back of a disk valve for each of the fluid flow systems for the extension and compression strokes. Damping force in a low piston speed region is controlled with a pressure control valve. The valve opening pressure of the disk valve is controlled by varying a pilot pressure introduced into the pilot chamber from a cylinder's hydraulic fluid chamber through a cut portion in a piston bolt and an orifice groove formed in a fixed member supporting the disk valve, thereby controlling damping force in a high piston speed region. A sharp pressure change occurring when the stroke direction of a piston rod changes is attenuated by the restricting action of the orifice groove so as not to be readily transmittable to the pilot chamber.
    Type: Grant
    Filed: May 30, 2001
    Date of Patent: November 5, 2002
    Assignee: Tokico Ltd.
    Inventors: Takuya Matsumoto, Takashi Nezu
  • Patent number: 6430927
    Abstract: A reservoir flange portion is formed in a leg portion of a reservoir so as to protrude beyond a seal member in a direction of a cylinder body and to extend radially outward. An annular retaining member, which has an outer diameter larger than the outer diameter of the reservoir flange portion and an inner diameter smaller than the outer diameter of the reservoir flange portion, is interposed between an engaging surface of the reservoir flange portion of the reservoir and an engaging surface of the seal member. By this arrangement, retention of the reservoir relative to the seal member and the cylinder body is markedly improved by means of the retaining member having an outer diameter larger than the outer diameter of the reservoir flange portion.
    Type: Grant
    Filed: November 30, 2000
    Date of Patent: August 13, 2002
    Assignee: Tokico Ltd.
    Inventors: Fumiaki Uno, Shinji Kajiro
  • Patent number: 6434460
    Abstract: By passing the vertical acceleration through a phase adjusting filter and a gain adjusting filter, the phase of the vertical acceleration is advanced by 49 degrees so that the phase difference with respect to the actual relative velocity becomes 180 degrees in the neighborhood of the vehicle body resonance point, thereby making the phase of the vertical acceleration, in effect, coincident with the phase of the relative velocity. In the neighborhood of the vehicle body resonance point (1 Hz), the gain of the estimated relative velocity takes a small value. In frequency regions other than the neighborhood of the vehicle body resonance point, the gain of the estimated relative velocity is increased. Consequently, the controlled variable in the neighborhood of the vehicle body resonance point increases, and the controlled variable in higher frequency regions decreases. Damping force is adjusted in correspondence to the controlled variable.
    Type: Grant
    Filed: July 25, 2001
    Date of Patent: August 13, 2002
    Assignee: Tokico Ltd.
    Inventors: Toru Uchino, Nobuyuki Ichimaru, Masaaki Uchiyama, Takahide Kobayashi
  • Patent number: 6427986
    Abstract: An air chamber (53) of a damping force adjusting mechanism (49) disposed in a hydraulic shock absorber (3) of a damping force adjusting type communicates with an air chamber (7) of an air spring through a tubular path (57). A free piston (51) is transferred in accordance with the pressure of the air chamber and a spool (46) is transferred to shift a damping force. The damping force presents a soft characteristic both on the extending side and on the retracting side in a usual status, presents a hard characteristic on the extending side and a soft characteristic on the retracting side when the pressure of the air chamber is high, and presents a soft characteristic on the extending side and a hard characteristic on the retracting side when the pressure of the air chamber (7) is low. The damping force can be obtained, which approximates the damping force control on the basis of a so-called sky-hook theory.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: August 6, 2002
    Assignee: Tokico, Ltd.
    Inventors: Hiroshi Sakai, Akinori Kurusu, Nobuyuki Ichimaru, Takao Kohara, Satoshi Ohsawa
  • Patent number: 6425312
    Abstract: The present invention provides a brake booster that, although simple in construction, capable of adjusting the braking force derived by operation of a solenoid mechanism without worsening the braking response. In the brake booster according to the present invention, when a movable member (34) is shifted toward the rear side by electromagnetic force of a solenoid (31), the shifting movement is transmitted to a valve seat member (21) through pins (50) to open an atmospheric valve (27) through which air is introduced into a variable pressure chamber (9,10), whereby a pressure difference is created between the variable pressure chamber and a constant pressure chamber and generates booster output (thrust output force).
    Type: Grant
    Filed: March 21, 2001
    Date of Patent: July 30, 2002
    Assignee: Tokico, Ltd.
    Inventors: Toshio Takayama, Kunihiro Matsunaga, Takuya Obata
  • Patent number: 6412884
    Abstract: A solenoid-controlled valve has first and second valve bodies axially movably provided in a bore of a cylinder. A first spring is interposed between an end of th valve and the first valve body, a second spring is interposed between the two valve bodies, and an electromagnetic force generating device has a movable member which causes the two valve bodies to move in association with each other. Valve opening and closing modes of the two valve bodies are changed in a plurality of stages according to the displacement of the movable member. A restricting portion restricts relative displacement of the two valve. bodies away from each other so that the influence of the urging force of the second spring on the driving force of the electromagnetic force generating device becomes zero in the valve opening and closing mode in the final stage.
    Type: Grant
    Filed: September 24, 1999
    Date of Patent: July 2, 2002
    Assignee: Tokico Ltd.
    Inventors: Toshio Takayama, Masaru Sakuma, Kunihiro Matsunaga
  • Patent number: 6412788
    Abstract: A suspension control system includes a shock absorber adapted to be mounted between a vehicle body and a wheel axle and having a variable damping force, an actuator operatively connected to the shock absorber and adapted to adjust the damping force developed by the shock absorber, an accelerometer for detecting terrain conditions and outputting a corresponding terrain condition signal, and a controller including a detector for determining terrain conditions in response to the frequency of the terrain condition signal and adapted to control the actuator in response to the terrain conditions as determined. The controller is operable to increase the damping force by a predetermined amount over a predetermined period of time when the accelerometer determines that the terrain includes a bump.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: July 2, 2002
    Assignee: Tokico Ltd.
    Inventor: Nobuyuki Ichimaru
  • Patent number: 6386087
    Abstract: The present invention provides a control booster which is capable of appropriately detecting a pedal-operated brake operation during an automatic brake operation. For moving a stop key from a position on a side of a rear-side abutment surface (where a reaction force of a switch acting on a switch operating rod and a spring force of a switch spring are balanced) toward an intermediate position, when the stop key is located on a side of the rear-side abutment surface, only a return force of the spring acts on a contact operating element of the switch. On the other hand, when the stop key moves toward the intermediate position, an abutment portion is separated from the contact operating element (that is, the switch operating rod moves in a direction for separation relative to the switch), so that no load is applied to the contact operating element.
    Type: Grant
    Filed: February 9, 2001
    Date of Patent: May 14, 2002
    Assignee: Tokico Ltd.
    Inventors: Toshio Takayama, Kunihiro Matsunaga, Takuya Obata
  • Patent number: 6374967
    Abstract: A damping force control type hydraulic shock absorber capable of generating stable damping force even if the flow rate of hydraulic fluid changes sharply. Hydraulic fluid chambers at the respective ends of valve members are cut off from the downstream ports of extension and compression pressure control valves by flange portions of the valve members. When the flow rate of hydraulic fluid increases sharply, even if the pressure in the downstream ports changes sharply owing to the flow resistance in check valves on the downstream side of the downstream ports, the pressure is not transmitted to the hydraulic fluid chambers. Therefore, there is no possibility of the slider moving under the influence of such a pressure change.
    Type: Grant
    Filed: November 30, 2000
    Date of Patent: April 23, 2002
    Assignee: Tokico Ltd.
    Inventors: Takuya Matsumoto, Takashi Nezu
  • Patent number: 6374958
    Abstract: A motor-driven disk brake has a first brake pad and a second brake pad disposed at opposite sides of a disk rotor, a piston disposed so as to face the first brake pad, a claw portion extending over the disk rotor and facing the second brake pad, and an electric motor disposed in the vicinity of the piston. A ball ramp mechanism for converting rotation of the electric motor to a linear motion is disposed between the first brake pad and the electric motor. When the motor is operated, the piston is reciprocally moved by the ball ramp mechanism, to thereby enable application and removal of a braking force relative to the disk rotor by the brake pads.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: April 23, 2002
    Assignee: Tokico Ltd.
    Inventors: Takuya Usui, Yukio Ohtani
  • Patent number: 6371262
    Abstract: The flow of a hydraulic fluid, which occurs under a sliding movement of a piston in a cylinder, is directly controlled by virtue of an extension-stroke pressure control valve and a compression-stroke pressure control valve. At the same time, the pressure in a back pressure chamber is varied, to thereby adjust the valve opening pressure for a main disk valve. This enables control of a damping force over a wide range. In each of the extension-stroke and compression-stroke pressure control valves, a thrust is generated in a slider due to a difference in pressure-receiving areas between a stepped portion of the slider and a sub disk valve in a valve chamber. The valve opening pressure is controlled, according to the balance between the thrust of the slider and a thrust of a proportional solenoid. By reducing the difference in the pressure-receiving areas in the valve chamber, the load applied to the proportional solenoid can be reduced.
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: April 16, 2002
    Assignee: Tokico Ltd.
    Inventors: Tetsuo Katou, Takashi Nezu, Takao Nakadate
  • Patent number: 6349806
    Abstract: In a cylinder body of a cylinder apparatus of the present invention for a brake fluid pressure control system, primary and secondary pistons having different pressure-receiving areas are provided. A pressure chamber between the primary and secondary pistons is communicated with a reservoir through flow passages formed between the cylinder body and a sleeve and between the sleeve and the secondary piston. In normal operation of the brake fluid pressure control system, the cylinder apparatus serves as a stroke simulator by releasing the fluid in the pressure chamber through the flow passages to the reservoir and contracting a spring in the pressure chamber. In the event of a failure of the system, the cylinder apparatus serves as a tandem master cylinder in which the flow passages are closed by a seal member in accordance with movement of the secondary piston, and the primary and secondary pistons move, while substantially no contraction of the spring in the pressure chamber occurs.
    Type: Grant
    Filed: September 15, 1999
    Date of Patent: February 26, 2002
    Assignee: Tokico Ltd.
    Inventors: Toshio Takayama, Kunihiro Matsunaga
  • Patent number: 6332622
    Abstract: The pilot suspension apparatus of the present invention is capable of biasing a damping valve in a direction for closing the valve, due to application of a pilot pressure. The suspension apparatus comprises at least one pair of hydraulic shock absorbers which are capable of controlling a damping force and which are connected by a connecting pipe. The at least one pair of hydraulic shock absorbers are provided at front and rear wheels or left and right wheels on the same side of a vehicle or are provided in a diagonally shaped relationship. A control valve is provided so as to control the pilot pressure. The control valve is adapted to be controlled by application of a differential pressure which is generated between respective cylinders of the at least one pair of shock absorbers.
    Type: Grant
    Filed: February 25, 2000
    Date of Patent: December 25, 2001
    Assignee: Tokico, Ltd.
    Inventors: Kenichi Nakamura, Takashi Nezu, Yoshiko Mihara
  • Patent number: 6329071
    Abstract: Using a chrome plating bath containing organic sulfonic acid, plating is conducted by application of a pulse current to thereby form a crack-free lower chrome layer on a steel substrate. The lower chrome layer has a compressive residual stress of 100 MPa or more and a crystal grain size of from 9 nm to less than 16 nm. Subsequently, by application of a direct current, a cracked upper chrome layer is formed on the lower chrome layer, to thereby obtain a chrome plated part. The lower chrome layer imparts the chrome plated part with heat resistance and corrosion resistance, and the upper chrome layer imparts the chrome plated part with wear resistance and good sliding properties.
    Type: Grant
    Filed: November 2, 1999
    Date of Patent: December 11, 2001
    Assignee: Tokico Ltd.
    Inventors: Yuichi Kobayashi, Junichi Nagasawa, Shoichi Kamiya, Toshiyuki Fukaya, Hiromi Yamauchi, Kazuo Watanabe
  • Patent number: 6325182
    Abstract: The present invention provides a motor driven brake system for generating and releasing braking forces by reciprocal movement of a pair of pads disposed at opposite sides of a disk having an axis. The system comprises a single electric motor, an output portion adapted to be rotated by the electric motor, a first pad pressing member for pressing a first pad against the disk a second pad pressing member for pressing a second pad against the disk, a first converting mechanism and second converting mechanism. The first converting mechanism converts rotation of the output portion to a linear motion so as to move the first pad pressing member reciprocally along the axis of the disk. The second converting mechanism converts rotation of the output portion to a linear motion so as to move the second pad pressing member reciprocally along the axis of the disk.
    Type: Grant
    Filed: March 22, 1999
    Date of Patent: December 4, 2001
    Assignee: Tokico, Ltd.
    Inventors: Tohma Yamaguchi, Youichi Kumemura, Yukio Ohtani, Takuya Usui