Patents Assigned to Tokico Ltd.
  • Patent number: 6321633
    Abstract: The present invention provides a booster in which magnitude of output can be adjusted also by an operation of a solenoid mechanism. An armature (13) is shifted to the right (in FIG. 1) in opposition to a returning spring by applying electricity to a solenoid (39), with the result that a space (80) on one end of the armature is communicated with a constant pressure chamber (5) through a passage (T3). When an electromagnetic force acting on the armature (13) exceeds a predetermined value, a distal end of a valve member (28) is shifted to the right (in FIG. 1) via a cylindrical member (31) to open an atmospheric valve (34), thereby introducing the atmosphere into a variable pressure chamber (6). The pressure in the variable pressure chamber is applied to the other end of the armature and the difference in the pressure tends to move the armature toward its home position.
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: November 27, 2001
    Assignee: Tokico Ltd.
    Inventors: Toshio Takayama, Kunihiro Matsunaga, Takuya Obata
  • Patent number: 6322058
    Abstract: A pressure-receiving chamber in an actuator and an air chamber of an air spring for displacing a shutter in a piston rod communicate with other through an air passage provided in the piston rod. The air passage includes a small-diameter hole of a rod insertion hole in the piston rod and an air hole formed in a side wall of the piston rod. By this arrangement, an external pipe such as used in a conventional air suspension apparatus for enabling communication between the actuator and the air spring becomes unnecessary, and the pressure in the air chamber is introduced into the pressure-receiving chamber in the actuator through the air passage in the piston rod. Therefore, a problem such as leakage of air can be avoided, leading to a reduction in the number of necessary parts.
    Type: Grant
    Filed: December 21, 1999
    Date of Patent: November 27, 2001
    Assignee: Tokico Ltd.
    Inventors: Fujio Tanigawa, Akimasa Amemiya
  • Patent number: 6321887
    Abstract: When a hydraulic cylinder apparatus operates in a direction such that the same damping force as a skyhook damping force cannot be produced, a command signal is applied so as to operate an active system (a fluid supply/discharge valve) and supply or discharge a fluid relative to the hydraulic cylinder apparatus, to thereby provide compensation of the damping force and obtain a desired damping force (shock-absorbing function). It is unnecessary to continuously supply or discharge the fluid through the active system and energy consumption can be reduced as compared to a conventional active control.
    Type: Grant
    Filed: June 29, 2000
    Date of Patent: November 27, 2001
    Assignee: Tokico Ltd.
    Inventors: Akinori Kurusu, Masaaki Uchiyama, Kenichi Nakamura
  • Patent number: 6311492
    Abstract: A master cylinder realizes a stroke simulator function without the need to change the structure around a brake pedal and without impairing brake pedal feel, is easy to form by machining, and also facilitates a hydraulic fluid charging and air bleeding operation. A secondary piston is split to make the axial length thereof variable, thereby imparting the stroke simulator function to the secondary piston. By doing so, brake pedal feel is improved more than by separately adding a stroke simulator.
    Type: Grant
    Filed: February 16, 2000
    Date of Patent: November 6, 2001
    Assignee: Tokico Ltd.
    Inventors: Toshio Takayama, Kunihiro Matsunaga
  • Patent number: 6302248
    Abstract: The flow of a hydraulic fluid between connecting ports caused by sliding movement of a piston in a cylinder is controlled by a fixed orifice and the flow path area determined by ports that is varied by a spool, thereby directly controlling orifice characteristics. At the same time, the pressure in a pilot chamber is changed by the pressure loss between the ports to change the valve opening pressure of a main valve, thereby controlling valve characteristics. An orifice passage is provided in parallel to the ports. Thus, when the flow path area determined by the ports is restricted, variations in the flow path area attributable to machining accuracy or the like can be absorbed by the flow path area of the orifice passage provided in parallel to the ports. Therefore, stable “hard” damping force characteristics can be obtained.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: October 16, 2001
    Assignee: Tokico Ltd.
    Inventor: Takao Nakadate
  • Patent number: 6302497
    Abstract: A vehicle brake control system includes a brake booster divided into a constant pressure chamber permanently communicating with a vacuum source, and a variable pressure chamber selectively communicating with the constant pressure chamber. The brake booster includes a first servo mechanism designed to develop a differential pressure between the two chambers, and a second servo mechanism. A master cylinder is operatively connected to the brake booster to create hydraulic pressure in response to the output of the brake booster, and hydraulic lines connect the master cylinder and the wheel cylinders. Pressure charging valves allow and block communication between the master and the wheel cylinders. Pressure relief valves between the pressure charging valves and the wheel cylinders selectively release the hydraulic pressure from the hydraulic lines.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: October 16, 2001
    Assignee: Tokico Ltd.
    Inventor: Toshio Takayama
  • Publication number: 20010025565
    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: Application
    Filed: March 21, 2001
    Publication date: October 4, 2001
    Applicant: Tokico, Ltd.
    Inventors: Toshio Takayama, Kunihiro Matsunaga, Takuya Obata
  • Patent number: 6290034
    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 detectors. Usual control for the actuators are performed on the basis of the vertical accelerations detected by the vertical acceleration detectors. A control signal adjustor 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 detector or a rate of change thereof exceeds a preset reference value.
    Type: Grant
    Filed: July 13, 1999
    Date of Patent: September 18, 2001
    Assignee: Tokico Ltd.
    Inventor: Nobuyuki Ichimaru
  • Patent number: 6283259
    Abstract: A hydraulic shock absorber includes an inner cylinder filled with a working oil, an outer cylinder, and a reservoir defined between the inner and outer cylinders. A piston is slidably disposed within the inner cylinder so as to divide the interior of the inner cylinder into an upper cylinder chamber and a lower cylinder chamber. A piston rod is connected to the piston. A tubular member is disposed between the inner and outer cylinders and has a radial port. A damper mechanism is attached to the outer cylinder so as to control the flow of the working oil to produce a damping resistance. The outer cylinder includes a mounting projection with a substantially flat top surface on which the damper mechanism is secured. A sleeve has one end inserted into the port of the tubular member and the other, flanged end terminating at the top surface of the mounting projection. A first sealing element is secured between the sleeve and the port to provide a seal between the sleeve and the tubular member.
    Type: Grant
    Filed: September 25, 1998
    Date of Patent: September 4, 2001
    Assignee: Tokico Ltd.
    Inventor: Takao Nakadate
  • Patent number: 6272858
    Abstract: A master cylinder includes a cylinder, a piston slidably provided in the cylinder, an annular cup seal held on an inner circumferential surface of the cylinder, and a relief port formed in the piston. The piston and the cylinder define a pressure chamber for generating fluid pressure in front of the piston, and the cylinder and an outer circumferential surface of the piston define a fluid supply chamber which communicates with a reservoir. The cup seal is adapted to slide against the outer circumferential surface of the piston to separate the fluid supply chamber from the pressure chamber. The relief port provides communication between the pressure chamber and the fluid supply chamber. A control taper surface is formed on the outer circumferential surface of the piston rearwardly from the relief port. The control taper surface is tapered toward the front of the piston and is capable of abutting against an inner circumferential surface of the cup seal.
    Type: Grant
    Filed: September 15, 1999
    Date of Patent: August 14, 2001
    Assignee: Tokico Ltd.
    Inventors: Eiichi Takano, Takato Ogiwara, Hiromi Ando
  • Patent number: 6269918
    Abstract: The flow of a hydraulic fluid caused by sliding movement of a piston in a cylinder is controlled by a disk valve and extension- and contraction-side main valves, thereby generating damping force. By controlling the valve opening pressures of the disk valve as a pressure control valve with respect to extension- and compression-side valve seats with a proportional solenoid actuator, damping force can be directly controlled independently of the piston speed. Moreover, the pressures in pilot chambers are changed to control the valve opening pressures of the extension- and compression-side main valves. Because the disk valve is placed between the extension- and compression-side valve seats, it is possible to simultaneously select different damping force characteristics for the extension and compression sides.
    Type: Grant
    Filed: December 28, 1999
    Date of Patent: August 7, 2001
    Assignee: Tokico Ltd.
    Inventors: Akinori Kurusu, Takashi Nezu
  • Patent number: 6269732
    Abstract: A pneumatic booster includes a valve mechanism for introducing atmospheric air into a variable-pressure chamber in accordance with the movement of a plunger, propelling a power piston due to differential pressure generated between the variable-pressure chamber and a constant-pressure chamber and transmitting force by which the power piston is propelled through a valve body to an output shaft. The valve mechanism includes a poppet valve mechanism including a seal surface capable of abutting against an annular atmospheric valve seat formed in the plunger and a seal surface capable of abutting against an annular negative pressure valve seat formed on an inner surface of the valve body. The annular atmospheric valve seat of the plunger is located in a position forward in a direction of propelling of the power piston relative to the negative pressure valve seat and is substantially aligned with the negative pressure valve seat in an axial direction.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: August 7, 2001
    Assignee: Tokico Ltd.
    Inventors: Hiromi Ando, Mitsuhiro Endo, Atsuya Koshu
  • Patent number: 6270064
    Abstract: In a self-pumping type hydraulic shock absorber, an outer cylinder is provided to cover an outer circumferential surface of a cylinder. The outer cylinder is formed to have a small-diameter portion, a mid-diameter portion and a large-diameter portion. A reservoir is formed between the large-diameter portion and the cylinder to communicate with upper and lower cylinder chambers. A cylinder member is fitted onto the mid-diameter portion and the large-diameter portion of the outer cylinder to form an oil tank between the cylinder member and the outer cylinder. A suspension spring (a coil spring) is provided between a spring seat attached to the small-diameter portion of the outer cylinder and a spring seat connected to a piston rod. Thus, the reservoir and the oil tank are provided inside the coil spring, so that each of the reservoir and the oil tank can be made to have a sufficiently large volume and the hydraulic shock absorber requires less space for mounting.
    Type: Grant
    Filed: June 30, 1999
    Date of Patent: August 7, 2001
    Assignee: Tokico Ltd
    Inventor: Junya Tachikawa
  • Patent number: 6267572
    Abstract: A scroll fluid machine requiring no crank shaft to orbitably support an orbiting scroll member and capable of being reduced in overall size in the axial direction. In a casing, two fixed scroll members are provided on the axis of the casing, and an electric motor is provided between the fixed scroll members. Eccentric bearings each having an outer ring, an intermediate ring and an inner ring are provided between the electric motor and the fixed scroll members. The inner periphery of each intermediate ring is formed with an axis eccentric with respect to the axis of the casing. Orbiting scroll members are integrated with the inner rings through an orbiting shaft. The orbiting shaft is caused to orbit by rotating a rotating shaft with the electric motor, thereby causing the orbiting scroll members to orbit relative to the fixed scroll members.
    Type: Grant
    Filed: October 28, 1999
    Date of Patent: July 31, 2001
    Assignee: Tokico Ltd.
    Inventors: Kazutaka Suefuji, Mineo Takahashi, Taisuke Torigoe
  • Patent number: 6250436
    Abstract: A motor-driven brake apparatus has a motor and a ball screw that converts rotational motion of the motor into rectilinear motion of a screw member. A position detector detects a stroke position of the screw member. A controller controls the motor on the basis of the result of detection by the position detector. The controller controls the motor so as to change the clearance between an inner pad (outer pad) and a disk according to vehicle running conditions.
    Type: Grant
    Filed: July 29, 1999
    Date of Patent: June 26, 2001
    Assignee: Tokico Ltd.
    Inventors: Hirotaka Oikawa, Tohma Yamaguchi, Youichi Kumemura, Toshio Takayama, Masaru Sakuma
  • Patent number: 6247561
    Abstract: In the disk brake, mounting portions of the caliper of a disk brake extending toward the entrance side and the exit side with respect to the rotation direction of the disk. Relative to the rotation direction, the length of the mounting portion on the entrance side is greater than that of the mounting portion on the exit side so that the cylinder portion is offset toward the exit side. Further, the mounting portion on the entrance side has thickenings formed to extend in a longitudinal direction thereof, so that with respect to the direction of the axis of the disk, the thickness of the mounting portion on the entrance side is greater than that of the mounting portion on the exit side. During braking, when a bending moment acts on the caliper, which can cause inclination of the caliper relative to the disk, flexural rigidity of the mounting portion on the entrance side is higher than that of the mounting portion on the exit side.
    Type: Grant
    Filed: July 28, 1999
    Date of Patent: June 19, 2001
    Assignee: Tokico, Ltd.
    Inventors: Kazuhiro Doi, Tadashi Tamasho, Tsutomu Hamabe, Hideaki Ishii, Takahiro Tokunaga
  • Patent number: 6231321
    Abstract: This invention pertains to an air compressor having a cylinder head with an air supply passage communicating with a discharge hole. First and second exhaust passages are arranged in parallel between the air supply passage and an exhaust port. A pilot-operated switching valve is located at an intermediate position in the first exhaust passage. A solenoid-operated exhaust valve is located at an intermediate position in the second exhaust passage. The solenoid-operated exhaust valve is selectively opened or closed by an externally supplied electric current, thereby controlling a pilot pressure applied to a valving element of the pilot-operated switching valve. The valving element is rested on or separated from a valve seat by the pilot pressure. The compressed air discharge speed can be increased without increasing the size of the cylinder head, and vehicle height adjustment, for example, can be made in a reduced period of time.
    Type: Grant
    Filed: July 29, 1999
    Date of Patent: May 15, 2001
    Assignee: Tokico Ltd.
    Inventors: Hiroshi Fukudome, Yoichi Mizutani, Kan Kobayashi
  • Patent number: 6223867
    Abstract: A disk pass portion for receiving a part of a disk is provided between a cylinder portion and an outer claw portion of a caliper body at the inner peripheral side of a bridge portion of the caliper body. A pair of mounting portions extend arcuately from both sides of the bridge portion to lie outside the disk pass portion with respect to the radial direction of the disk. A pair of sliding pins are secured to the distal ends of the mounting portions through pin bolts and slidably fitted in pin-fitting holes provided in a mounting member supporting the caliper. When the brake is activated, friction pads are pressed against the disk by the caliper. At this time, deformation of the caliper by reaction forces from the disk is small around the area where proximal portions of the mounting portions are connected to the caliper body.
    Type: Grant
    Filed: October 7, 1998
    Date of Patent: May 1, 2001
    Assignees: Tokico LTD, Nissan Motor Co., Ltd.
    Inventors: Kazuhiro Doi, Tadashi Tamasho, Hideaki Ishii, Takahiro Tokunaga, Joichi Yokoo, Shinji Suzuki
  • Patent number: 6210137
    Abstract: A scroll fluid machine having a lubrication pump provided between sliding contact surfaces of an orbiting scroll member and a thrust bearing in a casing. The pump has an orbiting member accommodating recess provided in the sliding contact surface of the thrust bearing. An orbiting member projects from the sliding contact surface of the orbiting scroll member into the recess. A slide plate defines a suction chamber and a discharge chamber in the recess. As the orbiting scroll member orbits, the orbiting member orbits in the recess, causing a lubricant contained in the casing to be sucked from a suction passage and delivered to the inside of a boss portion accommodating an orbiting bearing.
    Type: Grant
    Filed: December 28, 1999
    Date of Patent: April 3, 2001
    Assignee: Tokico Ltd.
    Inventors: Yoshio Kobayashi, Susumu Sugiura, Kiminori Iwano, Yasuhiko Sekino, Katsushi Hidano, Susumu Sakamoto, Junichi Nagasawa, Toshitsugu Suzuki
  • Patent number: 6203118
    Abstract: When a stroke speed exceeds a reference value of a stroke speed threshold value, a solenoid is energized to tract an armature, thereby opening an atmospheric valve independently of the position of a plunger. Consequently, power pistons, together with an output rod, are moved forward by a thrust corresponding to a pressure difference between a constant-pressure chamber and a variable-pressure chamber to perform a full-power braking operation. A reaction-adjusting mechanism contributes to an improvement in safety by functioning in such a way that when the part of the reaction force from the output shaft that is transmitted to an input rod reaches a predetermined value, a boosting ratio is increased, so that the reference value of the stroke speed threshold value can be set high to prevent unnecessary braking.
    Type: Grant
    Filed: September 22, 1998
    Date of Patent: March 20, 2001
    Assignee: Tokico Ltd.
    Inventors: Toshio Takayama, Masaru Sakuma, Kunihiro Matsunaga