Patents by Inventor Kazuo Takiguchi
Kazuo Takiguchi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20210047803Abstract: There is provided a hydraulic drive device for a working machine with which a number of times of maintenance can be reduced. A controller (20) opens a first on-off valve (25a), closes a second on-off valve (25b), switches a first directional switching valve (30a) to a first position (A), and switches a second directional switching valve (30b) to a third position (C), thereby pressure oil from a hydraulic pump (1a) is supplied from the first on-off valve to an actuator (5a) through the first directional switching valve. When history data of the first on-off valve is determined to satisfy a prescribed condition, the controller closes the first on-off valve, opens the second on-off valve, switches the first directional switching valve to a second position (B), and switches the second directional switching valve to a fourth position (D), thereby pressure oil from the hydraulic pump is supplied from the second on-off valve to the actuator through the second directional switching valve.Type: ApplicationFiled: August 5, 2019Publication date: February 18, 2021Inventors: Yoshifumi TAKIMOTO, Kazuo TAKIGUCHI, Chinori IIO, Jun OKAMURA, Hiromasa TAKAHASHI
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Patent number: 10907323Abstract: There is provided a hydraulic drive device for a working machine with which a number of times of maintenance can be reduced. A controller (20) opens a first on-off valve (25a), closes a second on-off valve (25b), switches a first directional switching valve (30a) to a first position (A), and switches a second directional switching valve (30b) to a third position (C), thereby pressure oil from a hydraulic pump (1a) is supplied from the first on-off valve to an actuator (5a) through the first directional switching valve. When history data of the first on-off valve is determined to satisfy a prescribed condition, the controller closes the first on-off valve, opens the second on-off valve, switches the first directional switching valve to a second position (B), and switches the second directional switching valve to a fourth position (D), thereby pressure oil from the hydraulic pump is supplied from the second on-off valve to the actuator through the second directional switching valve.Type: GrantFiled: August 5, 2019Date of Patent: February 2, 2021Assignee: Hitachi Construction Machinery Co., Ltd.Inventors: Yoshifumi Takimoto, Kazuo Takiguchi, Chinori Iio, Jun Okamura, Hiromasa Takahashi
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Patent number: 10443746Abstract: A main spool (24) has a throttle passage (30) that, when the main spool (24) moves to an axial other side against a first return spring (27) in a main spool insertion hole (13), communicates a pilot pressure chamber (25) with a first tank port (15) and limits a flow amount of hydraulic oil to be discharged to the first tank port (15) from the pilot pressure chamber (25). When the main spool (24) moves to the axial other side along the main spool insertion hole (13), the throttle passage (30) communicates the pilot pressure chamber (25) with the first tank port (15) before a state where a first pump port (17) is communicated with an output port (16) and a state where the output port (16) is blocked from the first tank port (15).Type: GrantFiled: January 16, 2017Date of Patent: October 15, 2019Assignee: Hitachi Construction Machinery Co., Ltd.Inventors: Jun Okamura, Takeshi Kobayashi, Mitsuhiro Yoshimoto, Kazuo Takiguchi, Masakazu Andou, Yoshifumi Takimoto
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Publication number: 20180245700Abstract: A main spool (24) has a throttle passage (30) that, when the main spool (24) moves to an axial other side against a first return spring (21) in a main spool insertion hole (13), communicates a pilot pressure chamber (25) with a first tank port (15) and limits a flow amount of hydraulic oil to be discharged to the first tank port (15) from the pilot pressure chamber (25). When the main spool (24) moves to the axial other side along the main spool insertion hole (13), the throttle passage (30) communicates the pilot pressure chamber (25) with the first tank port (15) before a state where a first pump port (17) is communicated with an output port (16) and a state where the output port (16) is blocked from the first tank port (15).Type: ApplicationFiled: January 16, 2017Publication date: August 30, 2018Inventors: Jun OKAMURA, Takeshi KOBAYASHI, Mitsuhiro YOSHIMOTO, Kazuo TAKIGUCHI, Masakazu ANDOU, Yoshifumi TAKIMOTO
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Publication number: 20140033699Abstract: A travel control device for a work vehicle includes: a hydraulic pump; a plurality of hydraulic motors connected to the hydraulic pump in parallel through a closed-circuit connection, that drive different wheels with pressure oil delivered from the hydraulic pump; a slip detection device that detects a slip occurring at each of the wheels; and a flow control device that reduces, upon detection of a slip occurring at any of the wheels by the slip detection device, a quantity of pressure oil supplied to a hydraulic motor for driving the wheel at which the slip has been detected, among the plurality of hydraulic motors.Type: ApplicationFiled: October 16, 2013Publication date: February 6, 2014Applicant: Hitachi Construction Machinery Co., Ltd.Inventors: Tsutomu Udagawa, Eiji Egawa, Tsukasa Toyooka, Makoto Sugaya, Hideo Sorata, Tsuyoshi Nakamura, Akira Nakayama, Kazuo Takiguchi, Kensuke Satou
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Patent number: 8585156Abstract: A travel control device for a work vehicle includes: a hydraulic pump; a plurality of hydraulic motors connected to the hydraulic pump in parallel through a closed-circuit connection, that drive different wheels with pressure oil delivered from the hydraulic pump; a slip detection device that detects a slip occurring at each of the wheels; and a flow control device that reduces, upon detection of a slip occurring at any of the wheels by the slip detection device, a quantity of pressure oil supplied to a hydraulic motor for driving the wheel at which the slip has been detected, among the plurality of hydraulic motors.Type: GrantFiled: November 1, 2006Date of Patent: November 19, 2013Assignee: Hitachi Construction Machinery Co., Ltd.Inventors: Tsutomu Udagawa, Eiji Egawa, Tsukasa Toyooka, Makoto Sugaya, Hideo Sorata, Tsuyoshi Nakamura, Akira Nakayama, Kazuo Takiguchi, Kensuke Satou
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Patent number: 7712565Abstract: A hydro-static transmission travel system for a working machine enables the working machine to travel over a range from low speed to high speed with a simplified circuit arrangement. By referring to a machine traveling speed (vehicle speed) based on a detected signal from a rotation sensor, a controller computes respective target tilting amounts of hydraulic motors 10, 20 and controls the tilting amount for the hydraulic motors and a clutch. Depending on whether the traveling speed exceeds a setting speed as a reference boundary, the controller selectively switches over a drive mode between low-speed four-wheel drive, in which travel units 12, 22 are both driven, and high-speed two-wheel drive, in which the front-wheel side hydraulic motor 10 is controlled to zero displacement and only the rear-wheel side travel unit 22 is driven.Type: GrantFiled: March 6, 2006Date of Patent: May 11, 2010Assignee: Hitachi Construction Machinery Co., Ltd.Inventors: Tsutomu Udagawa, Eiji Egawa, Akira Nakayama, Kazuo Takiguchi, Tsukasa Toyooka, Makoto Sugaya, Kensuke Sato
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Publication number: 20090127928Abstract: A travel control device for a work vehicle includes: a hydraulic pump; a plurality of hydraulic motors connected to the hydraulic pump in parallel through a closed-circuit connection, that drive different wheels with pressure oil delivered from the hydraulic pump; a slip detection device that detects a slip occurring at each of the wheels; and a flow control device that reduces, upon detection of a slip occurring at any of the wheels by the slip detection device, a quantity of pressure oil supplied to a hydraulic motor for driving the wheel at which the slip has been detected, among the plurality of hydraulic motors.Type: ApplicationFiled: November 1, 2006Publication date: May 21, 2009Inventors: Tsutomu Udagawa, Eiji Egawa, Tsukasa Toyooka, Makoto Sugaya, Hideo Sorata, Tsuyoshi Nakamura, Akira Nakayama, Kazuo Takiguchi, Kensuke Satou
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Patent number: 7500360Abstract: A hydraulic drive system comprises directional flow control valves (10a-f) for selectively supplying a hydraulic fluid from a first hydraulic pump (1a, 1b), inflow control valves (201-203) disposed respectively in branch lines (150A-C) branched from a supply line (100) for supplying a hydraulic fluid delivered from a second hydraulic pump (3a, 3b) to rod pushing-side chambers (5aA, 5bA, 6A, 7A) of hydraulic cylinders, a bypass flow control valve (204) disposed in a line (104) connecting the supply line (100) and a reservoir (2), and a controller (31) for computing control variables corresponding to operation command signals from control levers (32, 33) and controlling the inflow control valves (201-203) and the bypass flow control valve (204) in accordance with the computed control variables. Thus, the number of flow control valves and the length of piping required for their connection can be reduced, and a total pressure loss can be further reduced.Type: GrantFiled: August 29, 2003Date of Patent: March 10, 2009Assignee: Hitachi Constuction Machinery Co., Ltd.Inventors: Tsutomu Udagawa, Kazuo Takiguchi, Masami Ochiai, Takashi Yagyuu, Yukihiko Sugiyama, Mitsuo Aihara
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Publication number: 20070235241Abstract: A hydro-static transmission travel system for a working machine enables the working machine to travel over a range from low speed to high speed with a simplified circuit arrangement. By referring to a machine traveling speed (vehicle speed) based on a detected signal from a rotation sensor, a controller computes respective target tilting amounts of hydraulic motors 10, 20 and controls the tilting amount for the hydraulic motors and a clutch. Depending on whether the traveling speed exceeds a setting speed as a reference boundary, the controller selectively switches over a drive mode between low-speed four-wheel drive, in which travel units 12, 22 are both driven, and high-speed two-wheel drive, in which the front-wheel side hydraulic motor 10 is controlled to zero displacement and only the rear-wheel side travel unit 22 is driven.Type: ApplicationFiled: March 6, 2006Publication date: October 11, 2007Inventors: Tsutomu Udagawa, Eiji Egawa, Akira Nakayama, Kazuo Takiguchi, Tsukasa Toyooka, Makoto Sugaya, Kensuke Sato
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Patent number: 7175155Abstract: The control valve apparatus holds a seat valve member in a position seated on a valve seat to thereby prevent a backward flow even if the pressure in the inlet chamber side becomes lower than the pressure in the outlet chamber side. With a pilot control valve member is in a closed state, when the pressure in the inlet chamber is higher, a pressurized medium is introduced to the control pressure chamber via a first valve unit and is cut off from the outlet chamber by a second valve unit. When the pressure in the outlet chamber is higher, the pressurized medium is introduced to the control pressure chamber via the second valve unit and is cut off from the outlet chamber by the first valve unit.Type: GrantFiled: April 22, 2005Date of Patent: February 13, 2007Assignee: Hitachi Construction Machinery Co., Ltd.Inventors: Kazuo Takiguchi, Masami Ochiai, Tsutomu Udagawa, Katsumi Ueno, Takashi Yagyu, Yukihiko Sugiyama, Mitsuo Aihara
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Publication number: 20050242310Abstract: The control valve apparatus holds a seat valve member in a position seated on a valve seat to thereby prevent a backward flow even if the pressure in the inlet chamber side becomes lower than the pressure in the outlet chamber side. With a pilot control valve member is in a closed state, when the pressure in the inlet chamber is higher, a pressurized medium is introduced to the control pressure chamber via a first valve unit and is cut off from the outlet chamber by a second valve unit. When the pressure in the outlet chamber is higher, the pressurized medium is introduced to the control pressure chamber via the second valve unit and is cut off from the outlet chamber by the first valve unit.Type: ApplicationFiled: April 22, 2005Publication date: November 3, 2005Inventors: Kazuo Takiguchi, Masami Ochiai, Tsutomu Udagawa, Katsumi Ueno, Takashi Yagyu, Yukihiko Sugiyama, Mitsuo Aihara
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Publication number: 20050175485Abstract: A hydraulic drive system has directional flow control valves (10a-f) for selectively supplying a hydraulic fluid, inflow control valves (201-203) disposed respectively in branch lines (150A-C) branched from a supply line (100) for supplying a hydraulic fluid to rod pushing-side chambers (5aA, 5bA, 6A, 7A) of hydraulic cylinders. A bypass flow control valve (204) is disposed in a line (104) connecting the supply line (100) and a reservoir (2). A controller (31) is provided for computing control variables corresponding to operation command signals from control levers (32, 33) and controlling the inflow control valves (201-203) and the bypass flow control valve (204) in accordance with the computed control variables. As a result, the number of flow control valves and the length of piping required for connection of the flow control valves can be further cut, and a total pressure loss can be further reduced.Type: ApplicationFiled: August 29, 2003Publication date: August 11, 2005Inventors: Tsutomu Udagawa, Kazuo Takiguchi, Masami Ochiai, Takashi Yagyuu, Yukihiko Sugiyama, Mitsuo Aihara
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Patent number: 4251425Abstract: A stabilized polycarbonate resin composition comprising a polycarbonate resin and a benzenephosphonate of the general formula ##STR1## wherein R.sub.1 and R.sub.2, independently from each other, are selected from the class consisting of hydrogen, alkyl groups having 1 to 22 carbon atoms and cycloalkyl groups having 5 to 10 carbon atoms, at least one of R.sub.1 and R.sub.2 being other than hydrogen. A stabilized colored polycarbonate resin composition is also provided by further incorporating a pigment and/or dye.Type: GrantFiled: December 12, 1978Date of Patent: February 17, 1981Assignee: Teijin Chemicals, Ltd.Inventors: Osamu Ohara, Kazuo Takiguchi