Patents by Inventor Yuji Kurematsu
Yuji Kurematsu 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: 20240102520Abstract: To provide a cam clutch unit that is easy to handle before assembly, with its components prevented from lifting or detachment, and that allows production with fewer machining steps and a lower level of difficulty, while also enabling unit thickness reduction. The cam clutch unit of the present invention includes: a plurality of cams arranged between an inner race and an outer race; a cage ring having a plurality of pocket portions that restrict relative circumferential movements of the cams; and an annular spring that biases the cams. The cams have an engagement step adapted to engage with the spring on one axial end face. The cage ring has a plurality of hook portions that restrict an axial movement of the annular spring. The hook portions have a pressing part that allows the spring to press the cams towards the other axial end.Type: ApplicationFiled: July 14, 2023Publication date: March 28, 2024Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Akira Morita, Hirokazu Tsuneda, Yuji Kurematsu
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Patent number: 11913503Abstract: To provide a simple-structured cam clutch that does not require precise control and is operable with a smaller drive force and less prone to damage on cam surfaces or inner and outer raceways. The cam clutch includes a plurality of cams circumferentially arranged between an inner race and an outer race and supported by a cage member, and a selector capable of changing an orientation of the cams. The selector includes a driven part allowing a rotation angle thereof to be controlled relative to the inner race or outer race to which the cage member is fixedly attached, and a selector body circumferentially displaceable relative to the driven part in a resilient manner by a spring-loaded mechanism. The selector body includes a cam orientation control protrusion capable of changing the orientation of the cams by making contact with the cams.Type: GrantFiled: April 18, 2023Date of Patent: February 27, 2024Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Eiichi Nakagawa, Tsubasa Sugiya, Yuji Kurematsu
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Publication number: 20240026940Abstract: An object of the present invention is to provide a positive clutch that has a high rigidity and simple structure, reduces friction loss, prevents noise generation, allows a size reduction, and helps extend a service life. The object is achieved by the following configuration: Roller support parts are formed on one of an outer circumferential surface of the inner race and an inner circumferential surface of the outer race, and pocket parts are formed on the other one of the inner race and outer race. The clutch is configured to stop relative rotation of the inner race and outer race by holding the rollers, which are disposed between the inner race and the outer race, between the roller support parts and pocket parts in the circumferential direction.Type: ApplicationFiled: July 10, 2023Publication date: January 25, 2024Applicant: TSUBAKIMOTO CHAIN CO.Inventor: Yuji Kurematsu
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Patent number: 11846329Abstract: To provide a simple-structured cam clutch that does not require precise control, uses a smaller drive force, provides improved clutch operation stability and high responsiveness, and offers more mode switch options. The cam clutch includes a plurality of cams circumferentially arranged between an inner race and an outer race. The cams are arranged in a plurality of rows adjacent each other in a direction of rotation axis. The cam clutch has a selector that allows a rotation angle thereof to be controlled relative to the inner race or the outer race. The selector has a cam orientation control surface capable of changing the orientation of at least one row of cams by making contact with a cam surface. The cam orientation control surface includes a cam release portion radially protruded toward the cams more than a cam actuator portion and moving the cams to a non-operating orientation.Type: GrantFiled: March 7, 2023Date of Patent: December 19, 2023Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Yuji Kurematsu, Tsubasa Sugiya, Eiichi Nakagawa
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Publication number: 20230366438Abstract: To provide a simple-structured cam clutch that does not require precise control and is operable with a smaller drive force and less prone to damage on cam surfaces or inner and outer raceways. The cam clutch includes a plurality of cams circumferentially arranged between an inner race and an outer race and supported by a cage member, and a selector capable of changing an orientation of the cams. The selector includes a driven part allowing a rotation angle thereof to be controlled relative to the inner race or outer race to which the cage member is fixedly attached, and a selector body circumferentially displaceable relative to the driven part in a resilient manner by a spring-loaded mechanism. The selector body includes a cam orientation control protrusion capable of changing the orientation of the cams by making contact with the cams.Type: ApplicationFiled: April 18, 2023Publication date: November 16, 2023Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Eiichi Nakagawa, Tsubasa Sugiya, Yuji Kurematsu
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Patent number: 11767891Abstract: To provide a cam clutch unit that reduces the number of machining steps and level of difficulty of cam clutch production and reduces rotation resistance caused by rollers. The cam clutch unit includes: a plurality of cams and a plurality of rollers circumferentially arranged between an inner race and an outer race that are coaxial and rotatable relative to each other; a cage ring having a plurality of pocket portions that restrict circumferential relative movements of the cams and the rollers; and an annular spring that biases the cams. The cams each have, on one axial end face, an engagement step that can engage with the spring. The cage ring has a plurality of hook portions that restrict axial movements of the annular spring.Type: GrantFiled: January 6, 2023Date of Patent: September 26, 2023Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Akihiro Fukuda, Hirokazu Tsuneda, Yuji Kurematsu
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Publication number: 20230296144Abstract: To provide a simple-structured cam clutch that does not require precise control, uses a smaller drive force, provides improved clutch operation stability and high responsiveness, and offers more mode switch options. The cam clutch includes a plurality of cams circumferentially arranged between an inner race and an outer race. The cams are arranged in a plurality of rows adjacent each other in a direction of rotation axis. The cam clutch has a selector that allows a rotation angle thereof to be controlled relative to the inner race or the outer race. The selector has a cam orientation control surface capable of changing the orientation of at least one row of cams by making contact with a cam surface. The cam orientation control surface includes a cam release portion radially protruded toward the cams more than a cam actuator portion and moving the cams to a non-operating orientation.Type: ApplicationFiled: March 7, 2023Publication date: September 21, 2023Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Yuji Kurematsu, Tsubasa Sugiya, Eiichi Nakagawa
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Patent number: 11761496Abstract: To provide a simple-structured cam clutch that does not require precise control, uses a smaller drive force for forcibly changing cam postures, and provides improved clutch operation stability and high responsiveness. The cam clutch includes a plurality of cams circumferentially arranged between an inner race and an outer race and supported by a cage member, and a selector allowing a rotation angle thereof to be controlled relatively to the inner race or the outer race to which the cage member is fixed. The selector has a cam posture control surface in contact with cam surfaces of the cams and capable of causing the cams to change posture thereof. The cam posture control surface includes a cam release portion radially protruded toward the cams more than a cam actuator portion and causing the cams to change posture thereof to a non-operating posture.Type: GrantFiled: February 7, 2023Date of Patent: September 19, 2023Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Yuji Kurematsu, Tsubasa Sugiya, Eiichi Nakagawa
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Publication number: 20230250855Abstract: To provide a simple-structured cam clutch that does not require precise control, uses a smaller drive force for forcibly changing cam postures, and provides improved clutch operation stability and high responsiveness. The cam clutch includes a plurality of cams circumferentially arranged between an inner race and an outer race and supported by a cage member, and a selector allowing a rotation angle thereof to be controlled relatively to the inner race or the outer race to which the cage member is fixed. The selector has a cam posture control surface in contact with cam surfaces of the cams and capable of causing the cams to change posture thereof. The cam posture control surface includes a cam release portion radially protruded toward the cams more than a cam actuator portion and causing the cams to change posture thereof to a non-operating posture.Type: ApplicationFiled: February 7, 2023Publication date: August 10, 2023Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Yuji Kurematsu, Tsubasa Sugiya, Eiichi Nakagawa
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Publication number: 20230228302Abstract: To provide a cam clutch unit that reduces the number of machining steps and level of difficulty of cam clutch production and reduces rotation resistance caused by rollers. The cam clutch unit includes: a plurality of cams and a plurality of rollers circumferentially arranged between an inner race and an outer race that are coaxial and rotatable relative to each other; a cage ring having a plurality of pocket portions that restrict circumferential relative movements of the cams and the rollers; and an annular spring that biases the cams. The cams each have, on one axial end face, an engagement step that can engage with the spring. The cage ring has a plurality of hook portions that restrict axial movements of the annular spring.Type: ApplicationFiled: January 6, 2023Publication date: July 20, 2023Applicant: TSUBAKIMOTO CHAIN CO.Inventors: Akihiro Fukuda, Hirokazu Tsuneda, Yuji Kurematsu
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Patent number: 11585414Abstract: To provide a simple-structured chain drive mechanism that can reduce the noise generated when the chain sits on the sprocket, prevent deterioration of power transmission efficiency, and retard the progress of wear on the sprocket or chain. The chain drive mechanism includes a sprocket having a plurality of teeth, and a chain having a plurality of link plates and configured to be put around the sprocket. The sprocket includes a pair of flanges protruding circumferentially around the sprocket such as to sandwich the plurality of teeth from sides. The chain includes a pair of seat portions on both sides of the chain so that the flanges abut on the seat portions from a circumferential direction of the sprocket when the chain sits.Type: GrantFiled: October 24, 2019Date of Patent: February 21, 2023Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Takahiro Kadono, Yuji Kurematsu
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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: 11493114Abstract: To provide a simple-structured chain guide with improved durability and capable of preventing detachment or breakage of a supplementary member and of reliably reducing vibration and noise. The chain guide includes a supplementary member made of a different material from a guide body. The supplementary member is configured to have an engaging hole, which allows attachment of the supplementary member to a side face of a support wall part provided between a guide part and a base part of the guide body.Type: GrantFiled: December 27, 2019Date of Patent: November 8, 2022Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Yuji Kurematsu, Kaori Mori
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Patent number: 11493120Abstract: To provide a sprocket that reduces the influence of tension fluctuations concurrent with load torque changes to suppress noise and vibration and that allows for a weight reduction while retaining high strength as well as enables high productivity, and a drive mechanism that uses this sprocket. Sprocket teeth are configured by providing a cushioning layer on tooth faces of tooth portions of a sprocket base body made of a high-rigidity material. The sprocket teeth include the cushioning layer that varies in thickness.Type: GrantFiled: February 26, 2020Date of Patent: November 8, 2022Assignee: TSUBAKIMOTO CHAIN CO.Inventor: Yuji Kurematsu
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Patent number: 11448292Abstract: To provide a tensioner that can keep the oil pressure in an oil pressure chamber stable and consistently generate suitable reaction force and damping force to impact loads to reduce looseness in the chain and noise. A piston is set such as to partition an inner space of a plunger into an adjustment space on the front side and the oil pressure chamber on the rear side, a piston restricting member restricting the movement of the piston toward the adjustment space. An oil relief mechanism is configured to cause the piston to move forward when oil pressure in the oil pressure chamber rises so as to discharge oil inside the oil pressure chamber to the outside. The piston restricting member has an orifice function that can control the amount of discharged oil.Type: GrantFiled: May 19, 2020Date of Patent: September 20, 2022Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Yuichiro Ishikawa, Osamu Yoshida, Yuji Kurematsu, Masanori Watanabe
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Patent number: 11402009Abstract: In a sprocket including a cushion ring coming into contact with link plates of a chain, the cushion ring includes, on an outer circumferential surface, a plurality of convex sections coming into contact with the link plates, and the plurality of convex sections are provided at corresponding positions to tooth tips at identical pitches to a plurality of teeth and include convex sections having different shapes.Type: GrantFiled: July 2, 2019Date of Patent: August 2, 2022Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Kaori Mori, Yuji Kurematsu
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Patent number: 11320027Abstract: An object of the present invention is to provide a tensioner that enables a sufficient amount of stroke for the plunger to be secured and allows for size and weight reductions without changing the size of the tensioner body. In the tensioner according to the invention, an oil supply path that supplies oil from outside to an oil reservoir chamber formed inside the plunger includes an oil supply space formed between an inner circumferential surface of the plunger bore and an outer circumferential surface of the plunger. The oil supply space is formed by a front-end communication groove formed on an inner circumferential surface of the plunger bore and communicating with a tensioner body oil supply hole, and a rear-end communication groove formed on an outer circumferential surface of the plunger and causing the front-end communication groove to communicate with a plunger oil supply hole.Type: GrantFiled: July 1, 2020Date of Patent: May 3, 2022Assignee: TSUBAKIMOTO CHAIN CO.Inventor: Yuji Kurematsu
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Patent number: 11248682Abstract: The problem to be solved is to provide a tensioner lever that inhibits friction-induced wear or seizure on a surface of a pivoting support boss contacting a shoulder bolt so that high durability is achieved, and that is easily producible and enables cost reduction. As a solution to the problem noted above, the tensioner lever includes a shoe having a traveling surface, a lever body, and a pivotal support boss provided at a proximal end of the lever body to allow a distal end thereof to swing. The shoe and the lever body are integrally formed and assembled together by double injection molding. The lever body includes a slide bearing member, and a connecting part that connects the slide bearing member and the shoe. The slide bearing member, the connecting part, and the shoe are made of the same synthetic resin, and configured as a continuous one-piece component.Type: GrantFiled: March 10, 2020Date of Patent: February 15, 2022Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Hiroshi Hashimoto, Yuji Kurematsu, Kaori Mori
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Patent number: 11231092Abstract: An object of the present invention is to provide a chain guide that eliminates the burden of assembling a guide shoe and a base member together, and prevents the guide shoe from being limited in its movement in the longitudinal guiding direction relative to the base member to improve durability. The guide shoe and the base member of the chain guide according to the invention are united by being integrally molded. The chain guide includes a fixed engaging part where the guide shoe engages with the base member such that the guide shoe is restricted from moving in the longitudinal guiding direction relative to the base member, and a movable engaging part where the guide shoe engages with the base member such that the guide shoe is slidable relative to the base member. A molding gate mark is positioned at or near the fixed engaging part.Type: GrantFiled: October 9, 2019Date of Patent: January 25, 2022Assignee: TSUBAKIMOTO CHAIN CO.Inventors: Yoshitaka Iwasaki, Kaori Mori, Yuji Kurematsu
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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