Patents Assigned to Tokico Ltd.
  • Patent number: 5480216
    Abstract: A load-responsive hydraulic control apparatus includes a valve operating member for opening a valve portion capable of permitting and preventing a master cylinder from communicating with the rear wheel cylinders of a rear wheel brake system. A plunger is provided for receiving hydraulic pressure from a branch path branched from the rear wheel brake system between the valve portion and the master cylinder and for opening the valve portion via the valve operating member when the received hydraulic pressure reaches predetermined hydraulic shifting pressure. An inertia valve blocks the branch path when predetermined deceleration is achieved.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: January 2, 1996
    Assignee: Tokico, Ltd.
    Inventor: Kunihiro Matsunaga
  • Patent number: 5476029
    Abstract: A pneumatic booster comprises a piston dividing a housing into front and rear chambers, the front chamber being is constant communication with a vacuum source, the rear chamber being selectively supplied with an atmospheric pressure source or a compressed air source, wherein a valve body of the piston includes a bore having a retainer mounted within, and an input rod movable within the retainer and having a compressed air passage extending therein, the bore of the valve body also having a first rear control valve and a second front control valve, such that movement of the input rod opens the first rear control valve to allow atmospheric air into the booster chamber and a further movement of the input rod opens the second front control valve to allow compressed air into the booster chamber, resulting in an increased output force of the booster.
    Type: Grant
    Filed: September 20, 1994
    Date of Patent: December 19, 1995
    Assignee: Tokico Ltd.
    Inventors: Hiromi Ando, Nobumaro Osaka, Yasuhiko Amari
  • Patent number: 5472268
    Abstract: The present invention relates to a brake fluid pressure control apparatus provided with a flow valve which, during the normal operation, when a spool is in the stationary position, a master cylinder communication port is communicated with a wheel cylinder communication port while the pump communication port is closed, and during an antiskid control operation, a pump communication port and a wheel cylinder communication port are communicated, as well as a switching device to switch between the first and the second conditions. In the first condition, a master cylinder communication port is communicated with the output fluid passage of the master cylinder while the communication between the pump communication port and the master cylinder communication port is shut off.
    Type: Grant
    Filed: October 7, 1993
    Date of Patent: December 5, 1995
    Assignee: Tokico Ltd.
    Inventors: Hiromi Ando, Kunihiro Matsunaga
  • Patent number: 5460636
    Abstract: An impurity scavenging system which scavenges impurities of off-gases discharged from a clean room of a production line for semiconductors. The impurity scavenging system has a gas introduction line through which gas to be processed (hereinafter referred as GSP) is discharged, a scavenging unit which stores scavenging liquid, a condenser for condensing vaporized liquid from the scavenging unit, a first pump which pumps the GSP of a discharging line connected with the downstream side of the condenser, a liquid source, a cleaning liquid line which connects the discharging line to a drain and a first valve having ports, including a first port connected with the condenser, a second port connected with the first pump, and a third port connected with one end of the cleaning line another end of which is connected to the drain, thereby selectively enabling a connection from the condenser to the first pump and a connection from the condenser to the cleaning line.
    Type: Grant
    Filed: November 30, 1993
    Date of Patent: October 24, 1995
    Assignees: Tokico Ltd., Mitsubishi Corporation
    Inventors: Hiroyuki Harada, Tsutomu Koinuma, Terufumi Iwata, Michio Nitta
  • Patent number: 5442915
    Abstract: The present invention provides a brake fluid pressure generator comprising a barometric pressure booster and a master cylinder interlocked to each other at an interlocking portion which has a stepped configuration. A return spring is attached to the stepped portion of the interlocking portion. A stopper is fixed to the large diameter part of the interlocking portion. The return spring has a diameter larger than the small diameter part of the interlocking portion. Because the interlocking portion comes inside the return spring when they come closer, the overall length of the master cylinder and the barometric pressure booster is made smaller. Configuration of the return spring remains simple and the number of members is maintained small.
    Type: Grant
    Filed: October 29, 1993
    Date of Patent: August 22, 1995
    Assignee: Tokico Ltd.
    Inventor: Kazunari Komatsu
  • Patent number: 5433513
    Abstract: The controller in tills anti-skid control apparatus sets the brake pressure of the oil cylinder of one wheel to one of the hydraulic pressure reduction mode and the hydraulic pressure holding mode when the one wheel has been judged to be showing an increasing speed and when the pair of wheels in which the one wheel is not included has been judged to show an increasing slippage in condition that the controller does not detect the slip of each wheel.
    Type: Grant
    Filed: April 29, 1994
    Date of Patent: July 18, 1995
    Assignee: Tokico Ltd.
    Inventor: Toshio Takayama
  • Patent number: 5431259
    Abstract: A damping force control type hydraulic shock absorber has a piston that has main hydraulic fluid passages and valve mechanisms and also has a piston rod connected thereto. One side of the cylinder of the shock absorber is provided with a damping force control mechanism having a guide member and a shutter, which open and close a bypass passage, and a valve mechanism that generates damping force by controlling the flow of hydraulic fluid through the bypass passage. Damping force characteristics are changed by rotating the shutter with a rotary actuator. Since the damping force control mechanism is provided on the side of the cylinder and the piston is provided with only the main hydraulic fluid passages and the valve mechanisms, the size of the piston assembly is relatively small. Accordingly, the stroke of the piston rod can be increased.
    Type: Grant
    Filed: November 18, 1993
    Date of Patent: July 11, 1995
    Assignee: Tokico, Ltd.
    Inventors: Yoichi Mizutani, Takao Nakadate, Takashi Nezu
  • Patent number: 5409090
    Abstract: A damping force control type hydraulic shock absorber includes a cylinder having a hydraulic fluid sealed therein. A piston is slidably fitted in the cylinder to divide the inside of the cylinder into two chambers. A main hydraulic fluid passage provides communication between the two chambers and has a damping force generating mechanism. A bypass passage also provides communication between the two chambers. A cylindrical guide member is provided in the bypass passage to provide communication between two portions of the bypass passage which lead to the two chambers, respectively, through ports provided in the side wall of the guide member. A cylindrical shutter is rotatably fitted in the guide member. The shutter has openings capable of aligning with the ports. The ports and the openings cooperate to provide a damping force which changes generally linearly as the shutter rotates.
    Type: Grant
    Filed: May 27, 1993
    Date of Patent: April 25, 1995
    Assignee: Tokico Ltd.
    Inventors: Akira Kashiwagi, Takashi Nezu, Takao Kohara
  • Patent number: 5404973
    Abstract: In a damping force control type hydraulic shock absorber according to the invention, an extension-side bypass passage extends through an extension-side chamber (17b) in a shutter (17). A check valve (28) allows the flow of hydraulic fluid only during the extension stroke. A contraction-side bypass passage extends through a contraction-side chamber (17a) in the same shutter (17). Disk valves (30) allow the flow of hydraulic fluid only during the contraction stroke. By rotating the shutter (17), alignment between an extension-side inlet port (31) and an extension-side inlet opening (34) changes and alignment between a contraction-side inlet port (32) and a contraction-side inlet opening (33) also changes, thereby controlling the passage area of each of the extension- and contraction-side bypass passages, and thus enabling different damping force characteristics to be simultaneously selected for the extension and contraction sides.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: April 11, 1995
    Assignee: Tokico Ltd.
    Inventors: Tetsuo Katoh, Takao Nakadate
  • Patent number: 5402867
    Abstract: A cylinder (7) having a hydraulic fluid sealed therein is fitted with a piston (8) having a piston rod (9) connected thereto. The piston rod (9) is provided with a bypass passage (B) (generating relatively small damping force). The passage area of the bypass passage (B) is controlled by varying the area of orifices formed by guide ports (21 and 22) and shutter ports (24 and 25) by rotating a shutter (23), thereby changing damping force characteristics. Auxiliary ports (34 and 35) are provided to open into the guide ports (21 and 22), respectively.
    Type: Grant
    Filed: March 9, 1994
    Date of Patent: April 4, 1995
    Assignee: Tokico Ltd.
    Inventors: Takao Nakadate, Takashi Nezu, Akira Kashiwagi
  • Patent number: 5397175
    Abstract: The present invention presents an economical fluid pressure control device particularly applicable to controlling the fluid pressure in the wheels of an automobile provided with an antiskid capability so that the unpleasant pedal kickbacks are prevented under various operating conditions of the wheels. This is achieved by providing at least two wheel cylinders for one pressure generation source, a reservoir and a pump. A flow valve provided on each of the wheel cylinders is provided with a simple flow switching device which control the position of a spool, disposed inside the flow valve, which assumes a stationary position for non-antiskid operation mode and a operation position for antiskid operation mode. When one of the wheels is in the antiskid operation mode, and the other wheel is in non-antiskid operation mode, the brake fluid discharged from the pump is not allowed to enter the flow valve disposed in the non-antiskid operation mode.
    Type: Grant
    Filed: February 16, 1993
    Date of Patent: March 14, 1995
    Assignee: Tokico Ltd.
    Inventors: Kunihiro Matsunaga, Toshio Takayama, Hiromi Ando
  • Patent number: 5397094
    Abstract: A device for supporting a saddle of a bicycle, a mountain bike, etc., which includes a support frame, a guide tube secured to the support frame, and a tubular support member upwardly biased by a spring means. The projecting end portion of the tubular support member is connected to a mounting member for the saddle so that the support member and the saddle mounting member are movable relative to each other in a direction transverse to the longitudinal axis of the support member. The saddle mounting member is swingably connected to the guide tube.
    Type: Grant
    Filed: December 23, 1992
    Date of Patent: March 14, 1995
    Assignee: Tokico, Ltd.
    Inventors: Tadao Aoyama, Tetsuo Yasumaru, Masayuki Saito
  • Patent number: 5386892
    Abstract: In the disclosed hydraulic shock absorber, damping force characteristics are adjusted in accordance with the frequency of stroke, and the damping force is made small at the time when the directions of stroke are changed from one to the other. Cylinder upper and lower chambers are communicated with each other through main hydraulic fluid passage and first and second bypass passages. During the extension stroke, the second bypass passage is cut off by a check valve, and a shutter in the first bypass passage is slid in accordance with the frequency of stroke by the fluid flowing through an orifice passage to regulate the passage area of the first bypass passage. During the contraction stroke, the first bypass passage is cut off by a check valve, and a shutter in the second passage is slid in accordance with the frequency of stroke by the fluid flowing through an orifice passage to regulate the passage area of the second bypass passage.
    Type: Grant
    Filed: September 17, 1993
    Date of Patent: February 7, 1995
    Assignee: Tokico, Ltd.
    Inventor: Masahiro Ashiba
  • Patent number: 5384706
    Abstract: A suspension system for a vehicle which has a hydraulic cylinder that extends and retracts in accordance with a change in the distance between a vehicle body and an axle to vary the volumetric capacity of a working chamber defined therein, an accumulator connected to the working chamber in the hydraulic cylinder, a control valve controlling the flow rate of oil charged into and discharged from the accumulator and the hydraulic cylinder, and a vehicle level sensor detecting a change in the above-described distance. The suspension system further has a control unit that controls the control valve, on the basis of a flow control signal obtained by multiplying the detected signal from the vehicle level sensor by an amplification factor, so as to restore the vehicle to a neutral state. The control unit is arranged to increase the amplification factor when the amount of the extension or retraction of the hydraulic cylinder is close to the extent of the full stroke thereof.
    Type: Grant
    Filed: October 20, 1993
    Date of Patent: January 24, 1995
    Assignee: Tokico Ltd.
    Inventors: Masaaki Uchiyama, Kenichi Nakamura, Takashi Nezu, Hidekatsu Ozaki
  • Patent number: 5368142
    Abstract: A damping force control type of hydraulic shock absorber includes a cylinder in which a piston is fitted to define two chambers. A main hydraulic fluid passage extends between the chambers, and a damping force generating mechanism is provided in the passage. A bypass passage is also provided between the two chambers. Two check valves are provided in the bypass passage and allow hydraulic fluid to flow in opposite directions, respectively, through the bypass passage. A first hydraulic fluid passage bypasses the first check valve and a second hydraulic fluid passage bypasses the second check valve. A control valve is provided to vary the sectional area of each of the first and second hydraulic fluid passages.
    Type: Grant
    Filed: December 4, 1992
    Date of Patent: November 29, 1994
    Assignee: Tokico Ltd.
    Inventors: Masahiro Ashiba, Takao Nakadate
  • Patent number: 5364122
    Abstract: A suspension control system for a vehicle includes a plurality of hydraulic cylinders interposed between the vehicle body and the respective axles of front right, front left, rear right and rear left wheels for controlling the vehicle height by the action of a hydraulic fluid charged into and discharged from the cylinders. A plurality of normally-closed charge-discharge valves are provided to correspond to respective of the hydraulic cylinders. When the hydraulic fluid is to be charged into or discharged from the hydraulic cylinders, among the charge-discharge valves, at least the left and right charge-discharge valves associated with either the front right and front left wheels or the rear right and rear left wheels are not opened simultaneously, but either of the left and right charge-discharge valves is selectively opened.
    Type: Grant
    Filed: April 1, 1993
    Date of Patent: November 15, 1994
    Assignee: Tokico Ltd.
    Inventor: Nobuyuki Ichimaru
  • Patent number: 5351790
    Abstract: A hydraulically adjustable suspension apparatus for an automobile has a proportional type of solenoid operated valve assembly for controlling the pressure or flow rate of a pressurized fluid introduced into a cylinder tube through a fluid passage. The fluid passage is formed in a piston rod so as to communicate a cylinder tube with a hydraulic control circuit. The solenoid operated valve assembly is integrally attached to either the piston rod or the cylinder tube outside of the cylinder tube.
    Type: Grant
    Filed: June 19, 1992
    Date of Patent: October 4, 1994
    Assignee: Tokico Ltd.
    Inventor: Hiromi Machida
  • Patent number: 5342080
    Abstract: A vehicle height control system has oil under pressure generated by a pump, the oil being charged into and discharged from a cylinder that is provided for each wheel through a charge-discharge valve. This action effects vehicle height control. The control system includes a gas spring that has two gas chambers and is connected to the cylinder. A pilot-controlled directional control valve has a pilot chamber and is provided on the gas spring so as to selectively communicate and cut off from each other the gas chambers. The directional control valve is drivable in response to charging and discharging of oil under pressure through a pilot line which is connected at one end thereof to the pilot chamber of the directional control valve and at the other end thereof to a passage connecting the charge-discharge valve and the pump.
    Type: Grant
    Filed: August 25, 1993
    Date of Patent: August 30, 1994
    Assignee: Tokico, Ltd.
    Inventor: Hiromi Machida
  • Patent number: 5335982
    Abstract: The present invention relates to a brake fluid pressure control apparatus in which a casing contains a pump communication port separately from a master cylinder communication port. A spool is also provided which limits the communication between the pump communication port and the master cylinder communication port in a manner such that the discharge pressure from the pump is not added directly to the master cylinder. Additionally, in the intake and discharge sides of the pump, a bypass channel is provided. In this bypass channel, a relief valve is provided which allows the escape of pressure force to the intake side of the pump in the case when the pressure force between the discharge side of the pump and the flow control valve increases to a high pressure.
    Type: Grant
    Filed: March 31, 1993
    Date of Patent: August 9, 1994
    Assignee: Tokico Ltd.
    Inventors: Hiromi Ando, Kunihiro Matsunaga, Kenji Sano, Satoru Suga
  • Patent number: 5327058
    Abstract: A control method for use in industrial robots, and particularly an advantageous control method for use in industrial robots having attached thereto and using work tools (for example, a spray gun having a state in which paint is sprayed and a state in which paint is not sprayed) having a plurality of operational states is disclosed. That is, it is a control method for use in industrial robots which teaches the first data, which determine the path of the robot, and the second data, which determine the position of the switching of the operational state of the work tool attached to the robot in the path, and controls the operation of the work tool by means of the switching of the operational state of the work tool based on the second data during the operation, based on the first data, of the robot.
    Type: Grant
    Filed: February 9, 1993
    Date of Patent: July 5, 1994
    Assignee: Tokico Ltd.
    Inventor: Tatsuya Rembutsu