Patents by Inventor Naosumi Tada

Naosumi Tada 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).

  • Patent number: 6680129
    Abstract: Chain parts and other steel articles are provided with hard, wear-resistant carbide coatings by tumbling them in a heated retort with a particulate mix which includes a source of vanadium and/or niobium. The steel substrate comprises a steel having at least 0.2% carbon, preferably 0.7-1.2%. Where the chromium content of the steel is 4-12%, preferably 4-8%, the chemical deposition process includes drawing a small amount of chromium from the steel substrate into the vanadium or niobium carbide coating, where it is distributed substantially homogeneously, helping to provide adhesion strength to the coating.
    Type: Grant
    Filed: October 28, 2002
    Date of Patent: January 20, 2004
    Assignee: BorgWarner Inc.
    Inventors: Yumin Wang, Yoshito Hanayama, Doug Fornell, Naosumi Tada, Kunihiko Mishima
  • Patent number: 6676550
    Abstract: A blade tensioner is configured with a blade shoe having a chain sliding face, several plate-spring-like blade springs stacked on the reverse side of chain sliding face of the blade shoe in order to apply a spring force to the blade shoe, and spacer members provided between respective adjoining blade springs and brought in contact with corresponding blade springs at least at two points separated from each other by a fixed distance. In such case, the blade springs contact the spacer members at a fixed span. Accordingly, the damping factor of the overall blade spring or system is constant, so that the damping performance of the blade tensioner can be stabilized.
    Type: Grant
    Filed: June 11, 2001
    Date of Patent: January 13, 2004
    Assignee: Borg-Warner Automotive K.K.
    Inventor: Naosumi Tada
  • Patent number: 6641496
    Abstract: A blade tensioner includes a blade shoe having a chain slide face, a plurality of blade springs for applying spring force to the blade shoe, and a spacer member interposed between the adjacent blade springs. Each of the blade springs is in the shape of a leaf spring. The blade springs are positioned and layered on the opposite side of the blade shoe from the chain slide face. The spacer member preferably contacts the corresponding blade spring at two contact points apart from each other at a uniform distance. In the blade tensioner of this invention, the blade spring contacts the spacer member at a constant span, which causes the damping coefficient of the whole blade spring to be constant and also causes the damping performance of the blade tensioner to be stable.
    Type: Grant
    Filed: December 18, 2001
    Date of Patent: November 4, 2003
    Assignee: BorgWarner Inc.
    Inventor: Naosumi Tada
  • Patent number: 6612953
    Abstract: A blade tensioner is configured with blade shoe having chain sliding face, base that supports base part of blade shoe while allowing it to pivot freely, and blade spring in which base part is fixed to tip part of blade shoe. Warped part provided at the tip contacts inner face of blade shoe, and curved part provided at the midpoint of base contacts sliding face of base. In this case, the damping force of the blade tensioner increases due to sliding resistance generated between warped part of blade spring and inner face and between curved part and sliding face.
    Type: Grant
    Filed: June 1, 2001
    Date of Patent: September 2, 2003
    Assignee: Borg Warner Morse TEC Japan K.K.
    Inventor: Naosumi Tada
  • Patent number: 6607850
    Abstract: Chain parts and other steel articles are provided with hard, wear-resistant carbide coatings by tumbling them in a heated retort with a particulate mix which includes a source of vanadium and/or niobium. The steel substrate comprises a steel having at least 0.2% carbon, preferably 0.7-1.2%. Where the chromium content of the steel is 4-12%, preferably 4-8%, the chemical deposition process includes drawing a small amount of chromium from the steel substrate into the vanadium or niobium carbide coating, where it is distributed substantially homogeneously, helping to provide adhesion strength to the coating.
    Type: Grant
    Filed: October 28, 2002
    Date of Patent: August 19, 2003
    Assignee: BorgWarner, Inc.
    Inventors: Yumin Wang, Yoshito Hanayama, Doug Fornell, Naosumi Tada, Kunihiko Mishima
  • Patent number: 6582765
    Abstract: Chain parts and other steel articles are provided with hard, wear-resistant carbide coatings by tumbling them in a heated retort with a particulate mix which includes a source of vanadium and/or niobium. The steel substrate comprises a steel having at least 0.2% carbon, preferably 0.7-1.2%. Where the chromium content of the steel is 4-12%, preferably 4-8%, the chemical deposition process includes drawing a small amount of chromium from the steel substrate into the vanadium or niobium carbide coating, where it is distributed substantially homogeneously, helping to provide adhesion strength to the coating.
    Type: Grant
    Filed: June 26, 2001
    Date of Patent: June 24, 2003
    Assignee: BorgWarner, Inc.
    Inventors: Yumin Wang, Yoshito Hanayama, Doug Fornell, Naosumi Tada, Kunihiko Mishima
  • Publication number: 20030104255
    Abstract: Chain parts and other steel articles are provided with hard, wear-resistant carbide coatings by tumbling them in a heated retort with a particulate mix which includes a source of vanadium and/or niobium. The steel substrate comprises a steel having at least 0.2% carbon, preferably 0.7-1.2%. Where the chromium content of the steel is 4-12%, preferably 4-8%, the chemical deposition process includes drawing a small amount of chromium from the steel substrate into the vanadium or niobium carbide coating, where it is distributed substantially homogeneously, helping to provide adhesion strength to the coating.
    Type: Application
    Filed: October 28, 2002
    Publication date: June 5, 2003
    Inventors: Yumin Wang, Yoshito Hanayama, Doug Fornell, Naosumi Tada, Kunihiko Mishima
  • Publication number: 20030098093
    Abstract: Chain parts and other steel articles are provided with hard, wear-resistant carbide coatings by tumbling them in a heated retort with a particulate mix which includes a source of vanadium and/or niobium. The steel substrate comprises a steel having at least 0.2% carbon, preferably 0.7-1.2%. Where the chromium content of the steel is 4-12%, preferably 4-8%, the chemical deposition process includes drawing a small amount of chromium from the steel substrate into the vanadium or niobium carbide coating, where it is distributed substantially homogeneously, helping to provide adhesion strength to the coating.
    Type: Application
    Filed: October 28, 2002
    Publication date: May 29, 2003
    Inventors: Yumin Wang, Yoshito Hanayama, Doug Fornell, Naosumi Tada, Kunihiko Mishima
  • Patent number: 6524202
    Abstract: A blade-type tensioner for chain drives which is suitable for use as a tensioner on the timing chain of a motor vehicle engine. The present invention is a chain tensioner particularly suited for use in confined spaces having a blade spring element mechanically interlocked with a plastic shoe. The shoe may be of rigid filled nylon and engages the chain to be tensioned. The spring element is interlocked to the plastic shoe by having ends inserted into grooves formed in the opposite ends of the shoe. The shoe has a metal bushing fixed in one end. The shoe is rotatably attached to a metal pin inserted through the bushing, the pin being fixed to a base.
    Type: Grant
    Filed: January 12, 2000
    Date of Patent: February 25, 2003
    Assignee: Borg-Warner Automotive, K.K.
    Inventors: Naosumi Tada, Shinji Tsuruta
  • Publication number: 20020142872
    Abstract: A blade tensioner is configured with a blade shoe provided with a chain sliding face, several plate-spring-like blade springs stacked on the reverse side of the chain sliding face of the blade shoe in order to apply a spring force to the blade shoe, and friction plates provided respectively between adjoining blade springs to increase the dampening of the blade tensioner.
    Type: Application
    Filed: June 13, 2001
    Publication date: October 3, 2002
    Applicant: Borg-Warner Automotive K.K.
    Inventor: Naosumi Tada
  • Publication number: 20020119852
    Abstract: A chain pin includes a carbide layer that is principally composed of vanadium carbide, but also contains a small quantity of chromium carbide formed on the top of the steel forming the base metal of the chain pin. A boundary layer (i.e., chrome-rich layer) is formed in the boundary region between the carbide layer and the base metal. The vanadium carbide content decreases sharply and the chromium carbide content increases sharply in the boundary layer. Since the carbide layer formed on the top of the base metal consists principally of vanadium carbide, it is possible to prevent peeling from the surface of the carbide layer. Moreover, the boundary layer between the carbide layer and the base metal contains a relatively large quantity of chrome, so the bonding force between the base metal and the carbide layer is increased via the boundary layer. This prevents the carbide layer from peeling from the base metal. Thus, even at high surface pressures, it is possible to improve the wear resistance of the pin.
    Type: Application
    Filed: November 21, 2001
    Publication date: August 29, 2002
    Inventors: Naosumi Tada, Yukio Yoshida, Rihei Yoshikawa, Ike Kiyoshi
  • Publication number: 20020119848
    Abstract: A blade tensioner includes a blade shoe having a chain slide face, a plurality of blade springs for applying spring force to the blade shoe, and a spacer member interposed between the adjacent blade springs. Each of the blade springs is in the shape of a leaf spring. The blade springs are positioned and layered on the opposite side of the blade shoe from the chain slide face. The spacer member preferably contacts the corresponding blade spring at two contact points apart from each other at a uniform distance. In the blade tensioner of this invention, the blade spring contacts the spacer member at a constant span, which causes the damping coefficient of the whole blade spring to be constant and also causes the damping performance of the blade tensioner to be stable.
    Type: Application
    Filed: December 18, 2001
    Publication date: August 29, 2002
    Inventor: Naosumi Tada
  • Patent number: 6440020
    Abstract: A blade-type chain tensioner includes a blade shoe having a chain sliding face, a blade spring biasing the blade shoe toward an associated chain, and a bracket to rotatably support the fixed end of the blade shoe. The length of the blade spring is shorter than that of the chain sliding face of the blade shoe. The first end of the blade spring is attached onto the fixed end of the blade shoe and slidably contacts the distal end of the bracket at a contact point located between the fixed and free ends of the shoe.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: August 27, 2002
    Assignee: Borg-Warner Automotive, K.K.
    Inventor: Naosumi Tada
  • Publication number: 20020115511
    Abstract: According to an embodiment of the invention, blade tensioner is configured with blade shoe having chain sliding face, base that supports base part of blade shoe while allowing it to pivot freely, and blade spring in which base part is fixed to tip part of blade shoe. Warped part provided at the tip contacts inner face of blade shoe, and curved part provided at the midpoint of base contacts sliding face of base. In this case, the damping force of the blade tensioner increases due to sliding resistance generated between warped part of blade spring and inner face and between curved part and sliding face.
    Type: Application
    Filed: June 1, 2001
    Publication date: August 22, 2002
    Applicant: Borg-Warner Automotive K.K.
    Inventor: Naosumi Tada
  • Patent number: 6435993
    Abstract: A hydraulic chain tensioner comprises a hollow plunger slidably received within the bore of a housing. A spring pushes the plunger in the protruding direction, and a pressure relief valve assembly and an air vent disc that are integrally incorporated on the upper end at the tip of the plunger. The air vent disc has a disc shape including a first and second face. An outer periphery is formed with a through-hole. The outer diameter of the air vent disc is slightly smaller than the inner diameter of the plunger. The first face is formed with a spiral groove and the circumferential edge portion of the first face is formed with a radius. The starting end of groove is disposed at the radius and the terminal end of the groove is centrally located on the first face.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: August 20, 2002
    Assignee: BorgWarner Inc.
    Inventor: Naosumi Tada
  • Publication number: 20020069539
    Abstract: A blade tensioner is configured with a base, a blade shoe having a chain sliding face provided on base, and several plate-spring-like blade springs stacked on the reverse side of the chain sliding face of the blade shoe in order to apply a spring force to blade shoe. A base part of blade shoe is provided in such a manner that it can pivot freely on the base, and a friction material is provided at the part where a tip part of the blade shoe contacts a sliding face of the base. In addition, respective edge parts of the blade springs are inserted into respective slots on the blade shoe.
    Type: Application
    Filed: June 12, 2001
    Publication date: June 13, 2002
    Applicant: Borg-Warner Automotive K.K.
    Inventor: Naosumi Tada
  • Publication number: 20020072442
    Abstract: A blade tensioner is configured with a blade shoe having a chain sliding face, several plate-spring-like blade springs stacked on the reverse side of chain sliding face of the blade shoe in order to apply a spring force to the blade shoe, and spacer members provided between respective adjoining blade springs and brought in contact with corresponding blade springs at least at two points separated from each other by a fixed distance. In such case, the blade springs contact the spacer members at a fixed span. Accordingly, the damping factor of the overall blade spring or system is constant, so that the damping performance of the blade tensioner can be stabilized.
    Type: Application
    Filed: June 11, 2001
    Publication date: June 13, 2002
    Applicant: Borg-Warner Automotive K.K.
    Inventor: Naosumi Tada
  • Publication number: 20020039941
    Abstract: A blade-type tensioner for chain drives which is suitable for use as a tensioner of the timing chain of a motor vehicle engine. The present invention is a chain tensioner particularly suited for use in confined spaces having a blade spring element mechanically interlocked with a plastic shoe. The shoe may be of rigid filled nylon and engages the chain to be tensioned. The spring element is interlocked to the plastic shoe by having ends inserted into grooves formed in the opposite ends of the shoe. The shoe is rotatably fixed to a base by way of a pin. The groove at the fixed end of the shoe extends towards the tip of the fixed end of the shoe past the pin attachment point. The groove at the free end of the shoe extends toward the tip of the free end of the shoe past the point at which the free end of the shoe bears upon a sliding surface formed on the base.
    Type: Application
    Filed: November 8, 2001
    Publication date: April 4, 2002
    Applicant: Borg-Warner Automotive, K.K.
    Inventors: Kensuke Nakamura, Ryohei Adachi, Naosumi Tada, Shinji Tsuruta
  • Patent number: 6364796
    Abstract: A blade-type tensioner for chain drives which is suitable for use as a tensioner on the timing chain of a motor vehicle engine. The present invention is a chain tensioner particularly suited for use in confined spaces having a blade spring element mechanically interlocked with a plastic shoe. The shoe may be of rigid filled nylon and engages the chain to be tensioned. The spring element is interlocked to the plastic shoe by having ends inserted into grooves formed in the opposite ends of the shoe. The shoe is rotatably fixed to a base by way of a pin. The groove at the fixed end of the shoe extends towards the tip of the fixed end of the shoe past the pin attachment point. The groove at the free end of the shoe extends toward the tip of the free end of the shoe past the point at which the free end of the shoe bears upon a sliding surface formed on the base.
    Type: Grant
    Filed: January 13, 2000
    Date of Patent: April 2, 2002
    Assignee: Borg-Warner Automotive K.K.
    Inventors: Kensuke Nakamura, Ryohei Adachi, Naosumi Tada, Shinji Tsuruta
  • Patent number: 6358168
    Abstract: A hydraulic tensioner for an engine timing chain includes a housing having a bore. The end portion of a plunger is slidably fitted into the bore. The end of an oil inlet provided in an engine block is fitted with a seal cap having a C-shaped cross section and an outside concavity. The hydraulic tensioner utilizes the concavity as an oil reservoir. Oil passages are formed in the housing to connect an oil chamber with the concavity. The seal cap has an orifice to connect the oil inlet with the concavity. The present invention results in decreased space occupied by and reduced manufacturing cost for a hydraulic tensioner having an oil reservoir.
    Type: Grant
    Filed: February 11, 2000
    Date of Patent: March 19, 2002
    Assignee: Borg-Warner Automotive K.K.
    Inventor: Naosumi Tada