Patents by Inventor Yudai Takagi
Yudai Takagi 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: 12013021Abstract: To provide a rotating member and a forming method thereof that allow formation of protrusions biting into an opposite surface to achieve high slip torque with a simple configuration. The rotating member includes a boss part and an anti-slip surface at least on one of both axial end faces of the boss part. The anti-slip surface has a plurality of corrugated rib parts, which includes a main groove and at least one auxiliary groove extending parallel to the main groove, with a ridge protruding higher than the anti-slip surface between the main groove and the auxiliary groove.Type: GrantFiled: August 6, 2020Date of Patent: June 18, 2024Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Osamu Yoshida, Yudai Takagi
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Patent number: 11499620Abstract: To provide a sprocket that reduces the influence of tension fluctuations concurrent with load torque variations to suppress noise and vibration, and that prevents an increase in tension fluctuations, noise, and vibration even when the chain tension is low and the load torque is small, and in regions where engagement between the chain and sprocket is free of the influence of tension. The sprocket has a plurality of seating points for the chain when the chain sits under no load set between adjacent pairs of the teeth such that their radial positions change in a circumferentially continuous manner. The radial positions of the seating points under no load have a variation pattern in which the radial positions increase and decrease depending on circumferential positions of the seating points.Type: GrantFiled: October 23, 2019Date of Patent: November 15, 2022Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Yuji Kurematsu, Yudai Takagi, Yuki Mizuno
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Patent number: 11198173Abstract: To provide a rotating member that allows formation of protrusions to be dug into an opposite surface with a simple configuration, and that can prevent a direction-dependent reduction of anti-slip effect and provide sufficient slip prevention in the direction of torque as well as in the radial direction, and a method of forming this rotating member. The rotating member has a boss and an anti-slip surface on at least one of both axial end faces of the boss. The anti-slip surface includes a plurality of crater-like depressions each having a peripheral protrusion. At least some of the plurality of crater-like depressions are arranged serially to form a plurality of crater chains.Type: GrantFiled: July 9, 2019Date of Patent: December 14, 2021Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Yudai Takagi, Yuji Kurematsu
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Patent number: 11125304Abstract: An orifice member is disposed in a plunger including a plunger hole that forms a hydraulic chamber in conjunction with a plunger housing hole in a housing. The orifice member includes a deformed fitting section deformed to fit on the inner circumferential surface of the plunger hole, a communication section that causes a surface in contact with the top surface on the front side of the plunger hole and a surface on the hydraulic chamber side to communicate, and an orifice groove that communicates with the communication section and an external relief hole provided in the plunger on the surface in contact with the top surface on the front side of the plunger hole to constitute an orifice.Type: GrantFiled: February 27, 2019Date of Patent: September 21, 2021Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Masanori Watanabe, Yudai Takagi, Yuji Kurematsu
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Publication number: 20210102613Abstract: To provide a rotating member and a forming method thereof that allow formation of protrusions biting into an opposite surface to achieve high slip torque with a simple configuration. The rotating member includes a boss part and an anti-slip surface at least on one of both axial end faces of the boss part. The anti-slip surface has a plurality of corrugated rib parts, which includes a main groove and at least one auxiliary groove extending parallel to the main groove, with a ridge protruding higher than the anti-slip surface between the main groove and the auxiliary groove.Type: ApplicationFiled: August 6, 2020Publication date: April 8, 2021Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Osamu Yoshida, Yudai Takagi
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Patent number: 10871208Abstract: Provided is a tensioner with which efficiency of recirculation of oil can be improved and dependency on oil supplied from an oil pump or the like can be reduced. The tensioner includes a pressure adjustment mechanism, wherein the pressure adjustment mechanism includes a cylinder portion and a piston that is disposed in the cylinder portion so as to be capable of moving in a front-rear direction and that divides an interior space into an oil storage chamber and an adjustment space, and a liquid-tight state is maintained between the cylinder portion and the piston in all positions between a position of the piston where the piston has moved closest to the oil storage chamber side and a position of the piston where the piston has moved closest to the adjustment space side.Type: GrantFiled: October 1, 2018Date of Patent: December 22, 2020Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Osamu Yoshida, Masanori Watanabe, Yudai Takagi, Yuji Kurematsu
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Patent number: 10851876Abstract: A tensioner capable of keeping oil pressure in an oil pressure chamber stable is provided. In the tensioner, a flow amount control mechanism includes a flow amount control member set inside a control space so as to be able to approach and separate from the oil pressure chamber, a control biasing unit, a first restricting part and a second restricting part. The flow amount control member and the inner wall of the control space are provided such that the flow resistance of a first control flow passage, which is exhibited when the flow amount control member contacts the first restricting part, is larger than the flow resistance of a second control flow passage, which is exhibited when the flow amount control member contacts the second restricting part.Type: GrantFiled: March 13, 2018Date of Patent: December 1, 2020Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Masanori Watanabe, Yudai Takagi
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Patent number: 10837527Abstract: To provide a tensioner capable of keeping, with a simple structure, oil pressure in an oil pressure chamber stable. The tensioner includes a pressure adjusting mechanism that adjusts oil pressure in the oil pressure chamber. The pressure adjusting mechanism includes a cylinder part, a piston unit set inside the cylinder part so as to be able to approach and separate from the oil pressure chamber, and piston biasing units that bias the piston unit toward the oil pressure chamber. A liquid tight seal condition is kept between the cylinder part and the piston unit at any position between a position where the piston unit has moved closest to the oil pressure chamber and a position where the piston unit has moved closest to the adjustment space. The piston biasing units include at least two piston springs.Type: GrantFiled: July 25, 2018Date of Patent: November 17, 2020Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Masanori Watanabe, Yudai Takagi, Osamu Yoshida, Yuji Kurematsu
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Patent number: 10683913Abstract: Provided is a tensioner which can ensure, with a simple structure, both the stability of the installation state of a check valve and the capacity of an oil storage chamber. A tensioner has a plunger, a housing, a check valve, and a coil spring. The plunger has a front-side plunger part having a pressing front end portion, and a rear-side plunger part disposed on the rear side of the front-side plunger part and having a valve movement restricting portion. The check valve is disposed on the rear side of the valve movement restricting portion. The coil spring is disposed so that one end thereof is in contact with a housing bottom portion and the other end thereof is in contact with the rear side of the check valve.Type: GrantFiled: September 19, 2017Date of Patent: June 16, 2020Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Munehiro Maeda, Yuji Kurematsu, Osamu Yoshida, Yudai Takagi
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Publication number: 20200158223Abstract: To provide a sprocket that reduces the influence of tension fluctuations concurrent with load torque variations to suppress noise and vibration, and that prevents an increase in tension fluctuations, noise, and vibration even when the chain tension is low and the load torque is small, and in regions where engagement between the chain and sprocket is free of the influence of tension. The sprocket has a plurality of seating points for the chain when the chain sits under no load set between adjacent pairs of the teeth such that their radial positions change in a circumferentially continuous manner. The radial positions of the seating points under no load have a variation pattern in which the radial positions increase and decrease depending on circumferential positions of the seating points.Type: ApplicationFiled: October 23, 2019Publication date: May 21, 2020Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Yuji Kurematsu, Yudai Takagi, Yuki Mizuno
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Publication number: 20200101517Abstract: To provide a rotating member that allows formation of protrusions to be dug into an opposite surface with a simple configuration, and that can prevent a direction-dependent reduction of anti-slip effect and provide sufficient slip prevention in the direction of torque as well as in the radial direction, and a method of forming this rotating member. The rotating member has a boss and an anti-slip surface on at least one of both axial end faces of the boss. The anti-slip surface includes a plurality of crater-like depressions each having a peripheral protrusion. At least some of the plurality of crater-like depressions are arranged serially to form a plurality of crater chains.Type: ApplicationFiled: July 9, 2019Publication date: April 2, 2020Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Yudai Takagi, Yuji Kurematsu
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Publication number: 20190323580Abstract: An orifice member is disposed in a plunger including a plunger hole that forms a hydraulic chamber in conjunction with a plunger housing hole in a housing. The orifice member includes a deformed fitting section deformed to fit on the inner circumferential surface of the plunger hole, a communication section that causes a surface in contact with the top surface on the front side of the plunger hole and a surface on the hydraulic chamber side to communicate, and an orifice groove that communicates with the communication section and an external relief hole provided in the plunger on the surface in contact with the top surface on the front side of the plunger hole to constitute an orifice.Type: ApplicationFiled: February 27, 2019Publication date: October 24, 2019Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Masanori Watanabe, Yudai Takagi, Yuji Kurematsu
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Publication number: 20190107178Abstract: Provided is a tensioner with which efficiency of recirculation of oil can be improved and dependency on oil supplied from an oil pump or the like can be reduced. The tensioner includes a pressure adjustment mechanism, wherein the pressure adjustment mechanism includes a cylinder portion and a piston that is disposed in the cylinder portion so as to be capable of moving in a front-rear direction and that divides an interior space into an oil storage chamber and an adjustment space, and a liquid-tight state is maintained between the cylinder portion and the piston in all positions between a position of the piston where the piston has moved closest to the oil storage chamber side and a position of the piston where the piston has moved closest to the adjustment space side.Type: ApplicationFiled: October 1, 2018Publication date: April 11, 2019Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Osamu Yoshida, Masanori Watanabe, Yudai Takagi, Yuji Kurematsu
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Publication number: 20190063562Abstract: To provide a tensioner capable of keeping, with a simple structure, oil pressure in an oil pressure chamber stable. The tensioner includes a pressure adjusting mechanism that adjusts oil pressure in the oil pressure chamber. The pressure adjusting mechanism includes a cylinder part, a piston unit set inside the cylinder part so as to be able to approach and separate from the oil pressure chamber, and piston biasing units that bias the piston unit toward the oil pressure chamber. A liquid tight seal condition is kept between the cylinder part and the piston unit at any position between a position where the piston unit has moved closest to the oil pressure chamber and a position where the piston unit has moved closest to the adjustment space. The piston biasing units include at least two piston springs.Type: ApplicationFiled: July 25, 2018Publication date: February 28, 2019Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Masanori Watanabe, Yudai Takagi, Osamu Yoshida, Yuji Kurematsu
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Patent number: 10094449Abstract: Provided is a chain tensioner that can always provide a suitable reaction force and damping force to various tension fluctuations of the chain, has a simple structure, is easy to produce, and also enables a reduction in the production cost. The chain tensioner 100 has a plunger 120 inserted in a plunger bore 111, and biasing means 140 for biasing the plunger in a protruding direction of the plunger. A plurality of biasing means 140 are accommodated so as to freely expand and contract inside a high pressure chamber 101 and arranged in series along the protruding direction of the plunger 120, with a separator plate 130 interposed therebetween. The separator plate 130 has one or more oil passages that adjust oil flow.Type: GrantFiled: April 11, 2016Date of Patent: October 9, 2018Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Yudai Takagi, Masatoshi Sonoda
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Publication number: 20180274637Abstract: A tensioner capable of keeping oil pressure in an oil pressure chamber stable is provided. In the tensioner, a flow amount control mechanism includes a flow amount control member set inside a control space so as to be able to approach and separate from the oil pressure chamber, a control biasing unit, a first restricting part and a second restricting part. The flow amount control member and the inner wall of the control space are provided such that the flow resistance of a first control flow passage, which is exhibited when the flow amount control member contacts the first restricting part, is larger than the flow resistance of a second control flow passage, which is exhibited when the flow amount control member contacts the second restricting part.Type: ApplicationFiled: March 13, 2018Publication date: September 27, 2018Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Masanori Watanabe, Yudai Takagi
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Publication number: 20180087628Abstract: Provided is a tensioner which can ensure, with a simple structure, both the stability of the installation state of a check valve and the capacity of an oil storage chamber. A tensioner has a plunger, a housing, a check valve, and a coil spring. The plunger has a front-side plunger part having a pressing front end portion, and a rear-side plunger part disposed on the rear side of the front-side plunger part and having a valve movement restricting portion. The check valve is disposed on the rear side of the valve movement restricting portion. The coil spring is disposed so that one end thereof is in contact with a housing bottom portion and the other end thereof is in contact with the rear side of the check valve.Type: ApplicationFiled: September 19, 2017Publication date: March 29, 2018Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Munehiro Maeda, Yuji Kurematsu, Osamu Yoshida, Yudai Takagi
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Patent number: 9541174Abstract: Provided is a chain tensioner that can, with a simple structure, supply sufficient and necessary oil when restarted after a long time after the stop of oil supply, and control pressing force in accordance with operating conditions during the drive, thereby reducing vibration of the chain not only when restarted but also during the drive. In a chain tensioner 100 in which a plunger 120 inserted in a plunger bore of a tensioner body 110 is biased outward by biasing means 140 provided in an oil pressure chamber 101 to be extendable and contractible, an oil supply hole 114, an oil supply space 102, and a plunger hole 124 that together form a continuous oil supply passage is formed in such a shape that an oil amount changes in accordance with a position of the plunger 120.Type: GrantFiled: March 18, 2015Date of Patent: January 10, 2017Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Yuji Kurematsu, Yudai Takagi
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Publication number: 20160305512Abstract: Provided is a chain tensioner that can always provide a suitable reaction force and damping force to various tension fluctuations of the chain, has a simple structure, is easy to produce, and also enables a reduction in the production cost. The chain tensioner 100 has a plunger 120 inserted in a plunger bore 111, and biasing means 140 for biasing the plunger in a protruding direction of the plunger. A plurality of biasing means 140 are accommodated so as to freely expand and contract inside a high pressure chamber 101 and arranged in series along the protruding direction of the plunger 120, with a separator plate 130 interposed therebetween. The separator plate 130 has one or more oil passages that adjust oil flow.Type: ApplicationFiled: April 11, 2016Publication date: October 20, 2016Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Yudai Takagi, Masatoshi Sonoda
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Publication number: 20150292602Abstract: Provided is a chain tensioner that can, with a simple structure, supply sufficient and necessary oil when restarted after a long time after the stop of oil supply, and control pressing force in accordance with operating conditions during the drive, thereby reducing vibration of the chain not only when restarted but also during the drive. In a chain tensioner 100 in which a plunger 120 inserted in a plunger bore of a tensioner body 110 is biased outward by biasing means 140 provided in an oil pressure chamber 101 to be extendable and contractible, an oil supply hole 114, an oil supply space 102, and a plunger hole 124 that together form a continuous oil supply passage is formed in such a shape that an oil amount changes in accordance with a position of the plunger 120.Type: ApplicationFiled: March 18, 2015Publication date: October 15, 2015Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Yuji Kurematsu, Yudai Takagi