Patents Assigned to Unitta Company
  • Patent number: 7588507
    Abstract: An autotensioner comprises a torsion coil spring interposed between a base and a rocking arm, and a tubular bushing provided between an inside surface of the base and an outside surface of the rocking arm. The torsion coil spring pushes and biases the rocking arm toward the bushing, and brings the pushing direction substantially in coincidence with the axial load direction of the force, acting on a stepped bolt supporting the rocking arm, from a belt. When the belt tension becomes high, the arm axial center displaces slightly from the base axial center, an extremely large first damping force acts on the rocking arm. When the belt tension becomes low, the smaller second damping force acts on the rocking arm.
    Type: Grant
    Filed: September 25, 2001
    Date of Patent: September 15, 2009
    Assignee: Unitta Company
    Inventors: Kazumasa Ayukawa, Hiromi Matsuura
  • Publication number: 20080274846
    Abstract: An autotensioner comprises a torsion coil spring interposed between a base and a rocking arm, and a tubular bushing provided between an inside surface of the base and an outside surface of the rocking arm. The torsion coil spring pushes and biases the rocking arm toward the bushing, and brings the pushing direction substantially in coincidence with the axial load direction of the force, acting on a stepped bolt supporting the rocking arm, from a belt. When the belt tension becomes high, the arm axial center displaces slightly from the base axial center, an extremely large first damping force acts on the rocking arm. When the belt tension becomes low, the smaller second damping force acts on the rocking arm.
    Type: Application
    Filed: May 2, 2008
    Publication date: November 6, 2008
    Applicant: UNITTA COMPANY
    Inventors: Kazumasa AYUKAWA, Hiromi MATSUURA
  • Patent number: 7384355
    Abstract: An autotensioner comprises a torsion coil spring interposed between a base and a rocking arm, and a tubular bushing provided between an inside surface of the base and an outside surface of the rocking arm. The torsion coil spring pushes and biases the rocking arm toward the bushing, and brings the pushing direction substantially in coincidence with the axial load direction of the force, acting on a stepped bolt supporting the rocking arm, from a belt. When the belt tension becomes high, the arm axial center displaces slightly from the base axial center, an extremely large first damping force acts on the rocking arm. When the belt tension becomes low, the smaller second damping force acts on the rocking arm.
    Type: Grant
    Filed: July 6, 2005
    Date of Patent: June 10, 2008
    Assignee: Unitta Company
    Inventors: Kazumasa Ayukawa, Hiromi Matsuura
  • Publication number: 20050250609
    Abstract: An autotensioner comprises a torsion coil spring interposed between a base and a rocking arm, and a tubular bushing provided between an inside surface of the base and an outside surface of the rocking arm. The torsion coil spring pushes and biases the rocking arm toward the bushing, and brings the pushing direction substantially in coincidence with the axial load direction of the force, acting on a stepped bolt supporting the rocking arm, from a belt. When the belt tension becomes high, the arm axial center displaces slightly from the base axial center, an extremely large first damping force acts on the rocking arm. When the belt tension becomes low, the smaller second damping force acts on the rocking arm.
    Type: Application
    Filed: July 6, 2005
    Publication date: November 10, 2005
    Applicant: UNITTA COMPANY
    Inventors: Kazumasa Ayukawa, Hiromi Matsuura
  • Patent number: 6908676
    Abstract: A transmission belt comprising a belt body and a cord. The belt body is made of a rubber composition. The cord is comprised of poly-p-phenylene benzobisoxazole fiber. The cord is embedded in the belt body. The belt body and the cord are formed into an integral whole by vulcanizing the rubber composition. The surface of the cord is subjected to a primary treatment involving coating a mixture of an epoxy compound and latex and heat treating, and a secondary treatment involving coating a resorcinol-formalin-latex adhesive and heat treating.
    Type: Grant
    Filed: January 22, 2002
    Date of Patent: June 21, 2005
    Assignee: Unitta Company
    Inventors: Hiroshi Sogabe, Shigehiro Isshiki, Hiroyuki Yamamoto
  • Patent number: 6767303
    Abstract: An autotensioner comprises a cup-shaped stationary member, an arm rotatably attached to an opening of the stationary member. An axial bore is formed in the bottom of the stationary member. A rocking wall extending to the bottom is provided at the arm. A first friction member is provided between the rocking wall and the inner wall of the opening. The first friction member is gripped between the rocking wall and the inner wall. A rocking shaft extending to the bottom is provided at the center of a lid portion of the arm. The rocking shaft is inserted in the axial bore. A second friction member is provided between the rocking shaft and the axial bore. The first friction member and the second friction member are formed of a synthetic resin mainly comprised of PPS, exhibit high limited PV factors, and exhibit low coefficients of friction.
    Type: Grant
    Filed: January 30, 2002
    Date of Patent: July 27, 2004
    Assignee: Unitta Company
    Inventor: Kazumasa Ayukawa
  • Patent number: 6605014
    Abstract: Toothed belt comprises teeth and bottoms which are alternately formed at one surface of the toothed rubber layer of the toothed belt. A fabric is provided at the outer surface of the teeth and the bottoms. A back rubber layer is integrally provided at the other surface of the toothed rubber layer. A plurality of cords are interposed at the interface between the toothed rubber layer and the back rubber layer. A large number of modified microfibers are intermixed throughout the toothed rubber layer. The modified microfibers consist of a copolymer of polyolefin and nylon fiber. The modified microfibers are oriented in the length direction of the toothed belt as a whole.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: August 12, 2003
    Assignee: Unitta Company
    Inventors: Shigehiro Isshiki, Tsutomu Tokunaga, Yoshitaka Sato
  • Publication number: 20030022746
    Abstract: An autotensioner comprises a cup-shaped stationary member, an arm rotatably attached to an opening of the stationary member. An axial bore is formed in the bottom of the stationary member. A rocking wall extending to the bottom is provided at the arm. A first friction member is provided between the rocking wall and the inner wall of the opening. The first friction member is gripped between the rocking wall and the inner wall. A rocking shaft extending to the bottom is provided at the center of a lid portion of the arm. The rocking shaft is inserted in the axial bore. A second friction member is provided between the rocking shaft and the axial bore. The first friction member and the second friction member are formed of a synthetic resin mainly comprised of PPS, exhibit high limited PV factors, and exhibit low coefficients of friction.
    Type: Application
    Filed: January 30, 2002
    Publication date: January 30, 2003
    Applicant: UNITTA COMPANY
    Inventor: Kazumasa Ayukawa
  • Patent number: 6497632
    Abstract: An autotensioner having a support shaft affixed to a base, and a cup of a swing member provided swingably about the support shaft. The cup opens to the base and houses inside it a torsion coil spring for biasing the pulley in the direction tensioning the belt. A damping member braking the swing member is fixed to the base. A ring-shaped spring brings it into close contact with the inner circumferential surface close to the opening of the cup. The damping member frictionally slides with the inner circumferential surface at the time of swing of the swing member and supports the swing member in the radial direction at the base side from the bearing supporting the support shaft.
    Type: Grant
    Filed: November 29, 2000
    Date of Patent: December 24, 2002
    Assignee: Unitta Company
    Inventors: Kazumasa Ayukawa, Hiromi Matsuura
  • Publication number: 20020177499
    Abstract: An autotensioner comprises a torsion coil spring interposed between a base and a rocking arm, and a tubular bushing provided between an inside surface of the base and an outside surface of the rocking arm. The torsion coil spring pushes and biases the rocking arm toward the bushing, and brings the pushing direction substantially in coincidence with the axial load direction of the force, acting on a stepped bolt supporting the rocking arm, from a belt. When the belt tension becomes high, the arm axial center displaces slightly from the base axial center, an extremely large first damping force acts on the rocking arm. When the belt tension becomes low, the smaller second damping force acts on the rocking arm.
    Type: Application
    Filed: September 25, 2001
    Publication date: November 28, 2002
    Applicant: UNITTA COMPANY
    Inventors: Kazumasa Ayukawa, Hiromi Matsuura
  • Publication number: 20020142147
    Abstract: A transmission belt comprising a belt body and a cord. The belt body is made of a rubber composition. The cord is comprised of poly-p-phenylene benzobisoxazole fiber. The cord is embedded in the belt body. The belt body and the cord are formed into an integral whole by vulcanizing the rubber composition. The surface of the cord is subjected to a primary treatment involving coating a mixture of an epoxy compound and latex and heat treating, and a secondary treatment involving coating a resorcinol-formalin-latex adhesive and heat treating.
    Type: Application
    Filed: January 22, 2002
    Publication date: October 3, 2002
    Applicant: UNITTA COMPANY
    Inventors: Hiroshi Sogabe, Shigehiro Isshiki, Hiroyuki Yamamoto
  • Patent number: 6406397
    Abstract: A toothed belt includes a toothed rubber layer having teeth formed on a surface thereof and containing a plurality of short fibers entirely distributed therein. The surface of the toothed rubber layer, on which the teeth are formed, is covered with a cover fabric. A back rubber layer is integrally applied to the other surface of the toothed rubber layer. A plurality of cord elements is disposed across a width of the belt and is intervened between the toothed rubber layer and the back layer in such a manner that a portion of each cord element is embedded in the toothed rubber layer, and the remaining portion thereof is embedded in the back rubber layer. The short fibers are entirely distributed in the toothed rubber layer and are regularly oriented.
    Type: Grant
    Filed: May 31, 2000
    Date of Patent: June 18, 2002
    Assignee: Unitta Company
    Inventors: Shigehiro Isshiki, Tsutomu Tokunaga, Yoshitaka Sato
  • Publication number: 20020010044
    Abstract: An autotensioner comprises a support shaft affixed to a base, and a cup of a swing member provided swingably about the support shaft. The cup opens to the base and houses inside it a torsion coil spring for biasing the pulley in the direction tensioning the belt. A damping member braking the swing member is fixed to the base. A ring-shaped spring brings it into close contact with the inner circumferential surface close to the opening of the cup. The damping member frictionally slides with the inner circumferential surface at the time of swing of the swing member and supports the swing member in the radial direction at the base side from the bearing supporting the support shaft.
    Type: Application
    Filed: November 29, 2000
    Publication date: January 24, 2002
    Applicant: UNITTA COMPANY
    Inventors: Kazumasa Ayukawa, Hiromi Matsuura
  • Publication number: 20010051555
    Abstract: Toothed belt comprises teeth and bottoms which are alternately formed at one surface of the toothed rubber layer of the toothed belt. A fabric is provided at the outer surface of the teeth and the bottoms. A back rubber layer is integrally provided at the other surface of the toothed rubber layer. A plurality of cords are interposed at the interface between the toothed rubber layer and the back rubber layer. A large number of modified microfibers are intermixed throughout the toothed rubber layer. The modified microfibers consist of a copolymer of polyolefin and nylon fiber. The modified microfibers are oriented in the length direction of the toothed belt as a whole.
    Type: Application
    Filed: May 14, 2001
    Publication date: December 13, 2001
    Applicant: UNITTA COMPANY
    Inventors: Shigehiro Isshiki, Tsutomu Tokunaga, Yoshitaka Sato
  • Patent number: 6264578
    Abstract: The tensioner comprises a cup fixed to an engine block and a pivot shaft which is fixed to a bolt engagement portion of the cup. The pivot shaft is inserted into a pivot bearing, and an arm is pivotally attached to the pivot shaft. The arm is biased by a torsion coil spring to rotate in a direction tensioning the belt. A sleeve having an axially extending slit is attached to an outer surface of the bolt engagement portion. One end of a coil spring is wound around the pivot bearing, and the other end is wound around the sleeve. The coil spring and the sleeve minutely deform by the rotation of the arm to generate a damping force. A damping force acting upon the arm when tensioning the belt is smaller than the damping force acting upon the arm when the belt is loosened.
    Type: Grant
    Filed: June 24, 1999
    Date of Patent: July 24, 2001
    Assignee: Unitta Company
    Inventor: Kazumasa Ayukawa
  • Patent number: 6117035
    Abstract: A toothed belt includes a front rubber layer having teeth formed in the front rubber layer. A plurality of short fibers are entirely distributed in the front rubber layer. A first side of the front rubber layer is covered with a cover fabric. A back rubber layer contacts a second side of the front rubber layer. A plurality of cord elements extend along a length of the belt and are interposed between the front rubber layer and the back rubber layer in such a manner that a portion of each cord element is embedded in the front rubber layer, and the remaining portion of each cord element is embedded in the back rubber layer.
    Type: Grant
    Filed: June 20, 1997
    Date of Patent: September 12, 2000
    Assignee: Unitta Company
    Inventors: Shigehiro Isshiki, Tsutomu Tokunaga, Yoshitaka Sato
  • Patent number: 6007897
    Abstract: A toothed belt has a plurality of teeth, which are arranged in the longitudinal direction thereof, and cords embedded in a back portion of the toothed belt. A facing fabric is covered over the teeth. The fabric used for the facing fabric is coated with latex. The solid deposition of latex is adjusted to between 50 and 200 wt % with respect to the weight of the base cloth.
    Type: Grant
    Filed: November 21, 1997
    Date of Patent: December 28, 1999
    Assignee: Unitta Company
    Inventors: Toshitaka Tamaki, Junji Yokoi
  • Patent number: 5803849
    Abstract: A belt tensioner has a tensioner and a tensioner arm. The tensioner cup has an opening, and the tensioner arm has a lid portion formed at one end. The lid portion is rotatably connected to the cup and extends so as to close the opening thereof. The tensioner also has a torsion spring provided in the cup to act between the cup and the arm so as to elastically urge the arm in a rotational direction. A damping member is secured to the lid portion of the arm such that an outer circumferential surface of the damping member is in sliding contact with an inner circumferential surface of the cup. Further, the tensioner has a ring-like spring provided in the damping member so as to elastically urge the damping member against the inner circumferential surface of the cup. The lid portion of the arm has at least two columnar pin-like elements protruding therefrom parallel with a swing axis of the lid portion of the arm, and the columnar pin-like elements are inserted in holes formed in the damping member.
    Type: Grant
    Filed: June 11, 1996
    Date of Patent: September 8, 1998
    Assignee: Unitta Company
    Inventor: Kazumasa Ayukawa
  • Patent number: 5584771
    Abstract: A power transmission belt includes a belt body having a tooth portion and made of a rubber stock of hydrogenated nitrile having a Mooney viscosity at 100.degree. C. of at least 90, whereby the internally generated heat of the belt body during use in a high temperature environment is suppressed. A cashew-modified phenol resin layer is formed at the outermost layer of the cords for bonding with the belt body. The cords are embedded in the longitudinal direction of the belt body.
    Type: Grant
    Filed: September 18, 1995
    Date of Patent: December 17, 1996
    Assignee: Unitta Company
    Inventors: Shigehiro Isshiki, Masami Sato, Yasuyuki Tatsumi, Yutaka Yoshimi
  • Patent number: 5501643
    Abstract: A power transmission belt comprised of a belt body having a tooth portion and made of a rubber stock of hydrogenated nitrile having a Mooney viscosity at 100.degree. C. of at least 90, whereby the internally generated heat of the belt body during use in a high temperature environment is suppressed. A cashew-modified phenol resin layer is formed at the outermost layer of the cords for bonding with the belt body. The cords are embedded in the longitudinal direction of the belt body.
    Type: Grant
    Filed: November 16, 1994
    Date of Patent: March 26, 1996
    Assignee: Unitta Company
    Inventors: Shigehiro Isshiki, Masami Sato, Yasuyuki Tatsumi, Yutaka Yoshimi