Patents by Inventor Kensuke Ioku
Kensuke Ioku 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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Patent number: 7549241Abstract: An arm direction changeover valve (11) is provided in an arm block (20). A first pilot check valve (18) is provided in a first block (21). A second pilot check valve (19) is provided in a second block (22). The three blocks, i.e., the arm block (20), the first block (21), and the second block (22) are arranged side by side. The first block (21) and the second block (22) are arranged to be contiguous to each other. Accordingly, an increase in size can be prevented even if a float mechanism and a multi-direction changeover valve are formed integrally with each other.Type: GrantFiled: July 7, 2006Date of Patent: June 23, 2009Assignee: Nabtesco CorporationInventors: Kensuke Ioku, Jun Nakano, Yasunori Hatanaka
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Patent number: 7350353Abstract: To provide a hydraulic circuit with a compact and simple structure while securing the amount of a hydraulic oil necessary for right and left running motors so as to prevent the limitation of a running speed. A first system has a changing valve for a right side running motor and a changing valve for a first actuator, and a second system has a changing valve for a left side running motor and a changing valve for a second actuator. The changing valves for the right side and the left side running motors and the changing valves for the first and second actuators are tandem-connected, respectively.Type: GrantFiled: March 29, 2006Date of Patent: April 1, 2008Assignee: Nabtesco CorporationInventor: Kensuke Ioku
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Patent number: 7263924Abstract: To simplify a circuit structure and a path structure in a hydraulic circuit having a pilot check valve and an overload relief valve and to reduce the size of a gear. The hydraulic circuit includes a pump port; a tank port; a first actuator port; a second actuator port; a first supply and discharge port; a second supply and discharge port; a direction changing valve; a first pilot check valve; a second pilot check valve; a first pilot path; and a first overload relief valve. The direction changing valve has a neutral position to communicate the first supply and discharge port with the tank port. The first overload relief valve is arranged in parallel with the first pilot check valve and is arranged between the first supply and discharge port and the first actuator port.Type: GrantFiled: March 29, 2006Date of Patent: September 4, 2007Assignee: Nabtesco CorporationInventor: Kensuke Ioku
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Publication number: 20070006491Abstract: An arm direction changeover valve (11) is provided in an arm block (20). A first pilot check valve (18) is provided in a first block (21). A second pilot check valve (19) is provided in a second block (22). The three blocks, i.e., the arm block (20), the first block (21), and the second block (22) are arranged side by side. The first block (21) and the second block (22) are arranged to be contiguous to each other. Accordingly, an increase in size can be prevented even if a float mechanism and a multi-direction changeover valve are formed integrally with each other.Type: ApplicationFiled: July 7, 2006Publication date: January 11, 2007Applicant: Nabtesco CorporationInventors: Kensuke Ioku, Jun Nakano, Yasunori Hatanaka
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Publication number: 20060249016Abstract: To simplify a circuit structure and a path structure in a hydraulic circuit having a pilot check valve and an overload relief valve and to reduce the size of a gear. The hydraulic circuit includes a pump port; a tank port; a first actuator port; a second actuator port; a first supply and discharge port; a second supply and discharge port; a direction changing valve; a first pilot check valve; a second pilot check valve; a first pilot path; and a first overload relief valve. The direction changing valve has a neutral position to communicate the first supply and discharge port with the tank port. The first overload relief valve is arranged in parallel with the first pilot check valve and is arranged between the first supply and discharge port and the first actuator port.Type: ApplicationFiled: March 29, 2006Publication date: November 9, 2006Applicant: Nabtesco CorporationInventor: Kensuke Ioku
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Publication number: 20060236688Abstract: To provide a hydraulic circuit with a compact and simple structure while securing the amount of a hydraulic oil necessary for right and left running motors so as to prevent the limitation of a running speed. A first system has a changing valve for a right side running motor and a changing valve for a first actuator, and a second system has a changing valve for a left side running motor and a changing valve for a second actuator. The changing valves for the right side and the left side running motors and the changing valves for the first and second actuators are tandem-connected, respectively.Type: ApplicationFiled: March 29, 2006Publication date: October 26, 2006Applicant: Nabtesco CorporationInventor: Kensuke Ioku
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Patent number: 7059237Abstract: In a multiple-switching valve having a bucket-leveling function, there are provided a diverged passage, which is diverged from a merged passage and connects with an unloading passage or a tank passage, and a switching valve to disconnect and connect the diverged passage. The switching valve allows a pressured oil drained from a rod-side chamber of a boom cylinder via a directional switching valve for boom to be supplied to the merged passage flow in the diverged passage, thereby preventing the pressure oil from being supplied to a head-side chamber of the bucket cylinder. Accordingly, the bucket-leveling function can be cancelled properly, thereby improving the operation of the multiple-directional switching valve.Type: GrantFiled: May 18, 2004Date of Patent: June 13, 2006Assignee: NABCO LimitedInventors: Kensuke Ioku, Jun Nakano
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Patent number: 7032378Abstract: There is provided a flow divider system in a hydraulic circuit for a work machine including a boom cylinder and a bucket cylinder. The flow divider system divides a pressured oil drained from a one-boom cylinder into an other-bucket cylinder and a tank via a first orifice, a second orifice and a flow dividing valve, maintaining a specified pressure difference between pressures downstream the first and second orifices. The first and second orifice are configured of a variable orifice respectively, and in the event that the oil flow from the one-boom chamber decreases, respective opening degrees of the first and second orifices are controlled so as to be reduced. Accordingly, changing of a divisional ratio of oil flow can be suppressed properly regardless of a small oil flow drained from the boom cylinder.Type: GrantFiled: May 18, 2004Date of Patent: April 25, 2006Assignee: Nabco LimitedInventors: Kensuke Ioku, Jun Nakano
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Publication number: 20040250677Abstract: There is provided a flow divider system in a hydraulic circuit for a work machine including a boom cylinder and a bucket cylinder. The flow divider system divides a pressured oil drained from a one-boom cylinder into an other-bucket cylinder and a tank via a first orifice, a second orifice and a flow dividing valve, maintaining a specified pressure difference between pressures downstream the first and second orifices. The first and second orifice are configured of a variable orifice respectively, and in the event that the oil flow from the one-boom chamber decreases, respective opening degrees of the first and second orifices are controlled so as to be reduced. Accordingly, changing of a divisional ratio of oil flow can be suppressed properly regardless of a small oil flow drained from the boom cylinder.Type: ApplicationFiled: May 18, 2004Publication date: December 16, 2004Applicant: NABCO LimitedInventors: Kensuke Ioku, Jun Nakano
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Publication number: 20040231505Abstract: In a multiple-switching valve having a bucket-leveling function, there are provided a diverged passage, which is diverged from a merged passage and connects with an unloading passage or a tank passage, and a switching valve to disconnect and connect the diverged passage. The switching valve allows a pressured oil drained from a rod-side chamber of a boom cylinder via a directional switching valve for boom to be supplied to the merged passage flow in the diverged passage, thereby preventing the pressure oil from being supplied to a head-side chamber of the bucket cylinder. Accordingly, the bucket-leveling function can be cancelled properly, thereby improving the operation of the multiple-directional switching valve.Type: ApplicationFiled: May 18, 2004Publication date: November 25, 2004Applicant: NABCO LimitedInventors: Kensuke Ioku, Jun Nakano
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Patent number: 6799424Abstract: A hydraulic circuit comprises a first and a second merging line capable of supplying pressure oil from a third pump for a third circuit to directional control valves in a first and a second circuit, respectively, and a merging valve for selectively communicating or cutting off the first and the second merging line with or from the third pump. The merging valve has a first shift position at which the third pump is connected to the second merging line, and a second shift position at which the third pump is connected to the first and the second merging line. The merging valve is shifted continuously between the shift positions. The hydraulic circuit can efficiently distribute pressure oil supplied from the third pump to the first and/or second circuit as well, and can prevent lowering of the operability of each of actuators connected to the first or second circuit.Type: GrantFiled: November 6, 2002Date of Patent: October 5, 2004Assignee: Nabco, Ltd.Inventors: Kensuke Ioku, Hitoshi Segawa
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Publication number: 20030089106Abstract: A hydraulic circuit comprises a first and a second merging line capable of supplying pressure oil from a third pump for a third circuit to directional control valves in a first and a second circuit, respectively, and a merging valve for selectively communicating or cutting off the first and the second merging line with or from the third pump. The merging valve has a first shift position at which the third pump is connected to the second merging line, and a second shift position at which the third pump is connected to the first and the second merging line. The merging valve is shifted continuously between the shift positions. The hydraulic circuit can efficiently distribute pressure oil supplied from the third pump to the first and/or second circuit as well, and can prevent lowering of the operability of each of actuators connected to the first or second circuit.Type: ApplicationFiled: November 6, 2002Publication date: May 15, 2003Applicant: Nabco, Ltd.Inventors: Kensuke Ioku, Hitoshi Segawa
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Patent number: 5243820Abstract: When a hydraulic circuit for driving actuators of a construction machine or the like includes a single hydraulic pump and a plurality of direction changeover valves connected to the hydraulic pump for controlling the respective actuators, operation of one of the direction changeover valves may result in undesirable change in the output oil pressure of the other direction changeover valves. The inventive hydraulic circuit includes means for driving a regulator of the hydraulic pump in response to any oil puressure change at the inlets of the direction changeover valves corresponding to the output oil pressure change, thereby compensating for the pressure change.Type: GrantFiled: June 18, 1991Date of Patent: September 14, 1993Assignee: Nippon Air Brake Kabushiki KaishaInventors: Ken-ichi Shimoura, Kensuke Ioku, Hiroaki Sakai
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Patent number: 5107753Abstract: An automatic pressure control device built in a hydraulic actuator driving circuit for driving a plurality of actuators of a construction machine or the like by a single hydraulic pump through respective pilot changeover valves is provided for automatically shuttling the changeover valve of each actuator to reduce its demanded flow rate and uniformly control the operation speeds of all actuators. To this end, the device is arranged to drain an excessive flow rate of the hydraulic pump through a series connection of a flow rate control valve controlled by the highest load pressure of the actuators and a resistance passage including a shuttle and to control the pilot pressure of each pilot changeover valve in response to a pressure at the junction of the series connection.Type: GrantFiled: August 8, 1991Date of Patent: April 28, 1992Assignee: Nippon Air Brake Kabushiki KaishaInventor: Kensuke Ioku