Patents Assigned to Tokico Ltd.
  • Patent number: 5092428
    Abstract: A drum brake in which a parking brake is incorporated. A parking brake lever is mounted in the interior of a vehicle and is operable to pull a parking lever through a cable. The rotation of the parking lever causes a pair of brake shoes to be forced tightly against a brake drum. This results in the generation of a braking force. A stopper member is provided to limit the maximum angular position of the parking brake. This design prevents contact of the parking lever with a rotary shaft due to excessive pulling of the parking lever and thus damage of the rotary shaft as well as the parking lever.
    Type: Grant
    Filed: July 19, 1990
    Date of Patent: March 3, 1992
    Assignee: Tokico Ltd.
    Inventors: Kinzo Kobayashi, Hideaki Ishii, Masahiko Yamamoto
  • Patent number: 5090726
    Abstract: A suspension control system for controlling the attitude of a vehicle has a hydraulic fluid supply source mechanism connected to a suspension unit of the vehicle through a hydraulic fluid supplying and discharging device for controlling the supply and discharge of hydraulic fluid to and from the suspension unit. The hydraulic fluid supply source mechanism includes a pump and a reservoir tank. The hydraulic fluid supply source mechanism further includes an unload line connecting a discharging port of the pump to the reservoir tank and an unload valve disposed in the unload line. The unload valve has an electromagnetic proportional valve and is controlled such that the current to be supplied thereto gradually increases and decreases when the valve is opened and closed, respectively.
    Type: Grant
    Filed: September 18, 1990
    Date of Patent: February 25, 1992
    Assignee: Tokico, Ltd.
    Inventor: Kenichi Nakamura
  • Patent number: 5090294
    Abstract: A pneumatic booster includes a casing, a valve body axially movably disposed in the casing and having a tubular portion extending backward to the outside of the casing and open at the rear end thereof, a set of a power piston and a diaphragm fixedly mounted on the valve body and partitioning the interior of the casing into a constant pressure chamber communicating with a negative pressure source and a variable pressure chamber adapted to selectively communicate with the negative source and the ambient air, a valve unit disposed in the tubular portion of the valve body for selectively placing the variable pressure chamber in communication with the negative pressure source and the ambient air, an input rod extending into the tubular portion of the valve body for actuating the valve unit, and an output rod connected to the valve body.
    Type: Grant
    Filed: November 1, 1990
    Date of Patent: February 25, 1992
    Assignee: Tokico Ltd.
    Inventor: Mitsuhiro Endou
  • Patent number: 5085300
    Abstract: A hydraulic damper according to the present invention includes a cylinder, working fluid disposed in the cylinder, a piston partitioning the cylinder into two fluid chambers and including passages therethrough for providing fluid communication between the two fluid chambers, and a damping force generation mechanism. The damping force generation mechanism includes a large diameter valve disc mounted adjacent the passages, a smaller diameter valve disc stacked against the large diameter valve disc, an inner pressure chamber formed adjacent and in fluid communication with the passages, and an outer pressure chamber formed adjacent and in fluid communication with the passages and formed radially outwardly of the inner pressure chamber. A partition wall is formed between the inner and outer pressure chambers and a passage is formed through the partition wall for communicating between the inner and outer pressure chambers.
    Type: Grant
    Filed: October 23, 1989
    Date of Patent: February 4, 1992
    Assignee: Tokico Ltd.
    Inventors: Tetsuo Kato, Tomio Imaizumi
  • Patent number: 5080446
    Abstract: A hydraulic pressure control device of a load sensing type is provided. The hydraulic pressure control device includes a spring support disposed on a vehicle body side or wheel side for supporting a suspension spring, a support member tiltably disposed in the spring support for supporting a load of the suspension spring at three support portions, and a hydraulic pressure control valve mounted on the support member for controlling hydraulic pressure supplied to a braking unit mounted on a wheel from a source for generating hydraulic braking pressure. Thus, at least a portion of the force applied to one of the support portions can be applied to a control piston of the hydraulic pressure control valve.
    Type: Grant
    Filed: September 11, 1990
    Date of Patent: January 14, 1992
    Assignee: Tokico Ltd.
    Inventor: Kunihiro Matsunaga
  • Patent number: 5072812
    Abstract: A hydraulic shock absorber includes a cylinder, a piston axially slidably fitted in the cylinder so as to divide the interior of the cylinder into a first cylinder chamber and a second cylinder chamber, and a damping force generating mechanism mounted on the piston for generating damping force by controlling the flow of the working fluid between the two chambers. The damping force generating mechanism comprises first and second passages and first and second recesses. The first passage is formed through the piston oblique to the axis of the piston and connects the first and second cylinder chambers. The first recess is formed in one end of the piston on the side of the outlet end of the first passage so as to include the outlet end of the first passage. The second passage is formed through the piston parallel to the axis of the piston, at a circumferential position differing from that of the first passage, and connects the first and second cylinder chambers.
    Type: Grant
    Filed: December 29, 1989
    Date of Patent: December 17, 1991
    Assignee: Tokico Ltd.
    Inventor: Tomio Imaizumi
  • Patent number: 5069605
    Abstract: A scroll fluid machine, such as a scroll vacuum pump or a scroll compressor, is disclosed and is capable of discharging substantially oil-free fluid. The scroll fluid machine comprises a casing, a drive shaft having an eccentric shaft portion, a scroll rotor supported on the eccentric portion of the drive shaft for revolution and having a scroll wrap, a scroll stator having a scroll wrap and attached to the open end of the casing with its scroll wrap in engagement with that of the scroll rotor to define a closed fluid compressing space together with the scroll wrap of the scroll rotor. Thrusts acting on the scroll rotor are sustained by thrust bearing portions formed in the end surface of the scroll stator, and an annular sealing member preformed of a flexible material in a U shape is disposed in a space defined between and by the scroll rotor and the scroll stator to isolate the closed fluid compressing space from the interior of the casing.
    Type: Grant
    Filed: March 14, 1990
    Date of Patent: December 3, 1991
    Assignee: Tokico Ltd.
    Inventors: Takashi Saitoh, Kohji Fukui
  • Patent number: 5065062
    Abstract: A motor-drive industrial robot which can be used as a painting robot is mainly constructed by a direct-drive motor, a fixed portion such as a base, and a movable portion such as a rotary table, an arm etc. The direct-drive motor for driving the movable portion is constructed by a rotor and a stator. Preferably, the stator is attached to the fixed portion, while the rotor is attached to the movable portion. In order to avoid the generation of sparks in the flammable atmosphere, this robot is designed as the explosion-proof construction, so that the protective gas ie enclosed within the direct-drive motor. This protective gas is supplied into an annular space formed between the rotor and stator via a through hole formed through the stator or rotor. In addition, this annular space is sealed such that the protective gas is not leaked from the direct-drive motor.
    Type: Grant
    Filed: October 19, 1989
    Date of Patent: November 12, 1991
    Assignee: Tokico Ltd.
    Inventors: Satoshi Uehara, Yukio Ohtani, Yoshiko Iriyama
  • Patent number: 5064032
    Abstract: A hydraulic shock absorber includes a damping force regulating valve constructed of a plurality of valve bodies for opening and closing one of passages connecting two chambers, a spring member provided on each valve body for biasing the valve body onto a valve seat, a plunger mounted on the valve bodies, and a solenoid into which the plunger extends for moving the plunger under a force corresponding to the value of the current fed to the solenoid to successively move the valve bodies. The passage is able to be opened and closed by controlling the current value so that a damping force is generated by controlling a flow of the hydraulic fluid in the passages, thus allowing the shock absorber to exhibit a plurality of damping force characteristics.
    Type: Grant
    Filed: March 2, 1990
    Date of Patent: November 12, 1991
    Assignee: Tokico Ltd.
    Inventor: Masahiro Ashiba
  • Patent number: 5058486
    Abstract: A pneumatic booster has a housing which includes a forward shell and a rearward shell, and a diaphragm which is installed inside the housing and secured at the outer peripheral portion thereof to the housing. The diaphragm has a bead formed on the outer peripheral portion thereof. The rearward shell has a bead retaining portion which has a bead retaining groove that opens radially outward. The forward shell has an outer peripheral portion. The bead is received into the bead retaining groove across one edge portion of the bead retaining groove and clamped between the groove and the outer peripheral portion of the forward shell. The dimensions of the bead and the bead retaining portion are set so that the inner diameter of the bead is greater than the outer diameter of the edge portion of the bead retaining groove. Thus, the rearward shell and the diaphragm can be assembled together without the need to bend the diaphragm in advance, and the assembly process is correspondingly facilitated.
    Type: Grant
    Filed: July 18, 1990
    Date of Patent: October 22, 1991
    Assignee: Tokico Ltd.
    Inventor: Mitsuhiro Endo
  • Patent number: 5046315
    Abstract: A master cylinder includes a cylinder defining a cylinder bore therein with one end of the cylinder being open, a sleeve fitted into the cylinder bore, a piston slidably disposed in the sleeve, and a stopper mounted on the one end of the cylinder for abutting against the sleeve to prevent the sleeve from coming off the cylinder. The sleeve includes at least two sleeve members fitted into the cylinder bore in serial disposition from the inner end to the open end of the cylinder bore. A cup seal is disposed between two adjacent sleeve members of the aforementioned at least two sleeve members. The master cylinder further includes a resilient member for forcing one inner sleeve member of the two adjacent sleeve members onto the other sleeve member of the two adjacent sleeve members, thereby forcing the other sleeve member toward the stopper.
    Type: Grant
    Filed: November 16, 1989
    Date of Patent: September 10, 1991
    Assignee: Tokico, Ltd.
    Inventors: Yoshihiro Nakamura, Naganori Koshimizu, Hideaki Ishii
  • Patent number: 5041991
    Abstract: A data conversion system for an industrial robot system comprises a first read/write apparatus loaded with a first recording disk recorded with a control data produced by a mother robot and a first scale data specifying a maximum rotational angle and a minimum rotational angle of an arm of the mother robot about a rotational axis, for reading out the control data and the first scale data from the recording disk, a second read/write apparatus loaded with a second recording disk recorded with a second scale data specifying a maximum rotational angle and a minimum rotational angle of an arm about a rotational axis of a duty robot for reading out the second scale data from the second recording disk, and a processor supplied with the control data and first scale data from said first read/write apparatus and further supplied with the second scale data from the second read/write apparatus for modifying the control data in proportion to ratio of the first and second scale data.
    Type: Grant
    Filed: March 14, 1989
    Date of Patent: August 20, 1991
    Assignee: Tokico Ltd.
    Inventor: Kazuyuki Fujiki
  • Patent number: 5035306
    Abstract: An adjustable damping force hydraulic shock absorber comprising a cylinder, a piston partitioning the interior of the cylinder into two chambers, a plurality of passages through which working fluid contained in the cylinder flows when the piston axially moves in the cylinder, a damping force generating mechanism for generating a damping force by controlling the flow of the working fluid through the passages, and a damping force regulating valve capable of regulating the damping force by opening or closing one specific passage of the plurality of passages.
    Type: Grant
    Filed: December 14, 1989
    Date of Patent: July 30, 1991
    Assignee: Tokico Ltd.
    Inventor: Masahiro Ashiba
  • Patent number: 5033590
    Abstract: A brake friction pad is provided with a recessed portion in one side of a backing plate and a riveting projection on the other side of the backing plate and a wear limit warning piece for a lining secured to the one side of the backing plate is riveted to the projection. The projection is formed with a plurality of steps. The wear limit warning piece is secured to the backing plate with an uppermost projecting portion of the projection fitted in a hole formed in the wear limit warning piece.
    Type: Grant
    Filed: March 19, 1990
    Date of Patent: July 23, 1991
    Assignee: Tokico Ltd.
    Inventors: Kinzo Kobayashi, Shinichi Nakayama
  • Patent number: 5029515
    Abstract: A pneumatic booster comprising a housing, a power piston separating the inside of the housing into a constant pressure chamber and a variable pressure chamber, a valve body attached to the power piston, an output shaft, a plunger slidably received in a bore in the valve body, an input shaft and a valve mechanism in the bore for selectively communicating the variable pressure chamber with a negative pressure source or the atmospheric pressure, the valve mechanism including a valve member mounted on the inner wall of the bore, a first valve seat formed on the inner wall of the bore and a second valve seat formed on the plunger.
    Type: Grant
    Filed: August 31, 1990
    Date of Patent: July 9, 1991
    Assignee: Tokico Ltd.
    Inventor: Mitsuhiro Endo
  • Patent number: 5018608
    Abstract: A hydraulic shock absorber comprising a cylinder, a partition member for partitioning the interior of the cylinder into two chambers and a damping force generating mechanism for regulating the oil flow through a communication passageway formed through the partition member and connecting the two chambers with each other. The damping force generating mechanism comprises a disk valve seated on a seat formed on the partition member and adapted to open in response to the oil pressure in the communication passageway; a damping force regulating chamber arranged on the side of the disk valve remote from the partition member; an oil passageway for connecting the damping force regulating chamber to the communication passageway; an orifice disposed in the oil passageway to restrict the area of the oil passageway for oil flow therethrough; and fulcrum member arranged in the damping force regulating chamber and in contact with the disk valve for providing a fulcrum for the disk valve to deflect.
    Type: Grant
    Filed: May 16, 1990
    Date of Patent: May 28, 1991
    Assignee: Tokico Ltd.
    Inventor: Tomio Imaizumi
  • Patent number: 5018796
    Abstract: A hydraulic pressure control valve for use in a brake system of a vehicle includes a valve member having a first projection which extends into an annular groove, in which a sealing member is disposed, when the valve member is at a predetermined position. Either the valve member or a cap that is disposed at an inlet port of the valve has a second projection through which the valve member can abut against the cap when the valve member moves toward the cap. The dimensions of the first and second projections are determined so that the distal end of the first projection is positioned so as to prevent the sealing member from coming out of the annular groove even when the valve member abuts against the cap. Thus, the sealing member is surely prevented from coming out of the annular groove when the hydraulic pressure control valve is assembled to the vehicle body, or when it is reassembled after being overhauled.
    Type: Grant
    Filed: May 11, 1990
    Date of Patent: May 28, 1991
    Assignee: Tokico Ltd.
    Inventors: Takashi Ishimaki, Toshio Simura
  • Patent number: 5004265
    Abstract: A suspension system effects attitude control of a vehicle by supplying and discharging a pressure fluid to and from a suspension unit disposed between the body of the vehicle and a wheel. The suspension system employs a variable displacement pump to constitute a pressure source for supplying a pressure fluid to the suspension unit and controls the pump by a control mechanism such that the discharge of the pump is maintained at a substantially constant level, thereby enabling the load applied to the engine of the vehicle to be maintained at a substantially constant level, and thus achievinhg an increase in output of the engine.
    Type: Grant
    Filed: September 19, 1989
    Date of Patent: April 2, 1991
    Assignee: Tokico Ltd.
    Inventor: Yoich Mizutani
  • Patent number: 5000041
    Abstract: Disclosed is a control apparatus for correcting the measurement of flow rates for use with a turbine-type flow meter in which the rotation of a turbine rotating in response to the flow velocity of fluid to be measured is detected to produce pulses which are, in turn, integrated to measure the flow rate of the fluid. The apparatus operates to obtain a value representing the rate of reduction in the flow rate from the pulse cycle in order to detect a first time at which the reduction rate increases above a first predetermined value and a second time at which the reduction rate decreases below a second predetermined value, produce a correction value on the basis of the pulse cycle at the second time and the time lag between the first and second times, and integrate pulses other than those generated in the period of time between the first and second times, adding the correction value from the correction value producing means to the integrated value.
    Type: Grant
    Filed: May 10, 1989
    Date of Patent: March 19, 1991
    Assignee: Tokico Ltd.
    Inventors: Yoshikazu Miyamoto, Kimio Toriyabe, Kazuo Tsuge, Hideaki Ikeda, Teruhisa Kojima, Masayuki Komaki, Yutaka Morita, Takatoshi Murakami, Yasuo Sato, Yasuo Koketu
  • Patent number: 4997068
    Abstract: A hydraulic damper for use in a vehicle capable of adjusting a damping force in accordance with road conditions. The hydraulic damper includes a cylinder chamber divided into two chambers by a piston, a bypass passage formed in the piston for communicating the two chambers, a plurality of damping force generation valves adaped to generate the damping forces in the extension side and the contraction side strokes, and a shutter for controlling the flow passage area of the bypass passage. Rotation of the shutter permits selective switching of the damping force generation valves to provide various kinds of damping force characteristics as suitable for the road condition.
    Type: Grant
    Filed: June 6, 1989
    Date of Patent: March 5, 1991
    Assignee: Tokico Ltd.
    Inventor: Masahiro Ashiba