Patents by Inventor Nobuaki Mitamura

Nobuaki Mitamura 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).

  • Publication number: 20030123770
    Abstract: A rolling bearing intended for longer life by improving seizure resistance and wear resistance in the circumstance with slip contact or in the circumstance where lubricant tends to be exhausted, which is manufactured by applying carburization or carbonitridation to an Si-added material to disperse and precipitate carbides or carbonitrides containing Si or Si—X (X=one or more of Mn, Mo, and Cr) thereby improving the seizure resistance and the wear resistance by the self-lubrication effect thereof, the size of the carbides or carbonitrides being preferably 10 &mgr;m or less for preventing flaking, and the area ratio for the carbides or carbonitrides being preferably 1.0-30% for obtaining sufficient self-lubrication effect.
    Type: Application
    Filed: December 6, 2002
    Publication date: July 3, 2003
    Applicant: NSK Ltd.
    Inventors: Sinji Fujita, Youicih Matsumoto, Yasuo Murakami, Nobuaki Mitamura, Shigeru Okita
  • Publication number: 20030072512
    Abstract: An object of the invention is to provide a small and low-cost variable polarization plane rotator that can control a rotation angle of the polarization plane easily, and an optical device using the same.
    Type: Application
    Filed: February 4, 2002
    Publication date: April 17, 2003
    Applicant: Fujitsu Limited
    Inventors: Hiroshi Nagaeda, Nobuaki Mitamura, Kazuaki Akimoto
  • Publication number: 20030021527
    Abstract: A movable mirror having a mirror surface reflecting a light input from an input fiber collimator is moved in an arrow (1) direction so that the reflection frequency of the input light reflected by an optical filter can be variable. The light is reflected plural times between the mirror surface and the optical filter, directed to a fixed mirror by the mirror surface, reflected by the fixed mirror, and is connected to an output fiber collimator. By moving the movable mirror in parallel, the reflection count of the light between the optical filter and the mirror surface is variable. Therefore, the wavelength characteristic of the light is obtained as an accumulated wavelength characteristic depending on the reflection count.
    Type: Application
    Filed: October 30, 2001
    Publication date: January 30, 2003
    Applicant: Fujitsu Limited
    Inventors: Nobuaki Mitamura, Norihisa Naganuma
  • Patent number: 6478894
    Abstract: At least any one of a bearing member (inner race, outer race and rolling element) is formed with a steel material containing 0.2 to 1.2 wt % of C, 0.7 to 1.5 wt % of Si, 0.5 to 1.5 wt % of Mo, 0.5 to 2.0 wt % of Cr, and 12 ppm or less of O. The bearing member is treated with carbonitriding, and thereafter, quenching and tempering so as to provide carbon concentration in the steel surface being 0.8 to 1.3 wt % and nitrogen concentration on the same being 0.2 to 0.8 wt %.
    Type: Grant
    Filed: July 22, 1999
    Date of Patent: November 12, 2002
    Assignee: NSK Ltd.
    Inventors: Nobuaki Mitamura, Kazuo Sekino, Yasuo Murakami
  • Publication number: 20020122256
    Abstract: Rays of light having respective wavelengths angular-dispersed and output from a VIPA plate are collected by a lens, and diffracted by a grating pair which is an optical path shift generation unit and optical path shift amount variation unit, and have a shift in a path of rays having different wavelengths. When the rays are reflected by a dispersion leveling three-dimensional mirror and input into the VIPA plate again, they are received by portions having different dispersion compensation amount of the three-dimensional mirror, thereby realizing different amounts of wavelength dispersion for respective wavelengths, and independently adjusting an amount of wavelength dispersion of the entire wavelengths of the WDM rays and the wavelength dispersion slope.
    Type: Application
    Filed: August 28, 2001
    Publication date: September 5, 2002
    Applicant: Fujitsu Limited
    Inventors: Nobuaki Mitamura, Yuichi Kawahata
  • Patent number: 6426022
    Abstract: A substrate 2 is autorotatably installed in a vacuum chamber 1 at an upper part thereof. MgF2 granules 3 as a film source material are put in a quartz boat 4 and mounted on a magnetron cathode 5. The magnetron cathode 5 is connected through a matching box 6 to a 13.56 MHz radio frequency power source 7. Cooling water 8 for holding the temperature of the magnetron cathode 5 constant flows on a lower face of the magnetron cathode 5. A side face of the vacuum chamber 1 is provided with gas introduction ports 9, 10 for introducing gas in the vacuum chamber 1. A shutter 11 is placed between the magetron cathode 5 and the substrate 2. This structure provides a process enabling forming a thin film at a high speed by sputtering, especially, a high speed sputtering enabling forming a thin fluoride film free of light absorption.
    Type: Grant
    Filed: September 20, 2001
    Date of Patent: July 30, 2002
    Assignee: Olympus Optical Co., Ltd.
    Inventors: Ken Kawamata, Nobuaki Mitamura
  • Patent number: 6413188
    Abstract: A toroidal type continuously variable transmission, includes: at least one pair of disks concentrically disposed on each other and rotatably supported independent from each other; a trunnion swingable about a pivot shaft; a displacement shaft including a support shaft portion and a pivot shaft portion that are parallel and eccentric to each other, the support shaft portion rotatably supported to the circular hole of the trunnion through a radial bearing, the pivot shaft portion being protruded from an inner surface of the middle portion of the trunnion; a power roller nipped between the concave surfaces of the pair of disks while being rotatably supported on an outer circumferential surface of the pivot shaft portion; and a thrust bearings located between the power roller and the inner surface of the middle portion of the trunnions. An eccentric quantity of the displacement shaft being a distance between the support shaft portion and the pivot shaft portion is within a range from 5 mm to 15 mm.
    Type: Grant
    Filed: June 22, 2001
    Date of Patent: July 2, 2002
    Assignee: NSK Ltd.
    Inventors: Takashi Imanishi, Nobuo Goto, Makoto Fujinami, Hiroshi Kato, Nobuaki Mitamura, Hiroyuki Itoh, Seiji Higuchi, Hiroshi Fukushima
  • Publication number: 20020033480
    Abstract: A substrate 2 is autorotatably installed in a vacuum chamber 1 at an upper part thereof. MgF2 granules 3 as a film source material are put in a quartz boat 4 and mounted on a magnetron cathode 5. The magnetron cathode 5 is connected through a matching box 6 to a 13.56 MHz radio frequency power source 7. Cooling water 8 for holding the temperature of the magnetron cathode 5 constant flows on a lower face of the magnetron cathode 5. A side face of the vacuum chamber 1 is provided with gas introduction ports 9, 10 for introducing gas in the vacuum chamber 1. A shutter 11 is placed between the magetron cathode 5 and the substrate 2. This structure provides a process enabling forming a thin film at a high speed by sputtering, especially, a high speed sputtering enabling forming a thin fluoride film free of light absorption.
    Type: Application
    Filed: September 20, 2001
    Publication date: March 21, 2002
    Applicant: Olympus Optical Co., Ltd.
    Inventors: Ken Kawamata, Nobuaki Mitamura
  • Patent number: 6358440
    Abstract: A substrate 2 is autorotatably installed in a vacuum chamber 1 at an upper part thereof. MgF2 granules 3 as a film source material are put in a quartz boat 4 and mounted on a magnetron cathode 5. The magnetron cathode 5 is connected through a matching box 6 to a 13.56 MHz radio frequency power source 7. Cooling water 8 for holding the temperature of the magnetron cathode 5 constant flows on a lower face of the magnetron cathode 5. A side face of the vacuum chamber 1 is provided with gas introduction ports 9, 10 for introducing gas in the vacuum chamber 1. A shutter 11 is placed between the magnetron cathode 5 and the substrate 2. This structure provides a process enabling forming a thin film at a high speed by sputtering, especially, a high speed sputtering process enabling forming a thin fluoride film free of light absorption.
    Type: Grant
    Filed: September 23, 1999
    Date of Patent: March 19, 2002
    Assignee: Olympus Optical Co., Ltd.
    Inventors: Ken Kawamata, Nobuaki Mitamura
  • Patent number: 6332714
    Abstract: An induction-hardened rolling bearing device used by disposing rolling elements in a raceway track member, with excellent cold drawability and improved wear resistance and extended service life, in which ingredients of an alloy for the raceway track member contain, from 0.40 to 0.90% of C, from 0.05 to 0.80% of Si, from 0.10 to 2.0% of Mn, from 0.05 to 0.50% of Ti and 0.03% or less of N, on the weight basis, induction hardening is applied at least to the raceway surface of the raceway track member, and Ti carbide and Ti carbonitride each having an average particle diameter of from 5 to 100 nm are dispersed on the surface and in the steels of the raceway track member to make the hardness of the raceway surface to HRC 59 or more.
    Type: Grant
    Filed: June 24, 1999
    Date of Patent: December 25, 2001
    Assignees: NSK Ltd., Sanyo Special Steel Co., Ltd.
    Inventors: Hiromichi Takemura, Nobuaki Mitamura, Yasuo Murakami, Tomonobu Yoshikawa, Shuhei Kitano, Kazuhiko Hiraoka
  • Patent number: 6328669
    Abstract: A toroidal type continuously variable transmission, includes: at least one pair of disks concentrically disposed on each other and rotatably supported independent from each other; a trunnion swingable about a pivot shaft; a displacement shaft including a support shaft portion and a pivot shaft portion that are parallel and eccentric to each other, the support shaft portion rotatably supported to the circular hole of the trunnion through a radial bearing, the pivot shaft portion being protruded from an inner surface of the middle portion of said trunnion; a power roller nipped between the concave surfaces of the pair of disks while being rotatably supported on an outer circumferential surface of the pivot shaft portion; and a thrust bearings located between the power roller and the inner surface of the middle portion of the trunnions. An eccentric quantity of the displacement shaft being a distance between the support shaft portion and the pivot shaft portion is within a range from 5 mm to 15 mm.
    Type: Grant
    Filed: June 25, 1999
    Date of Patent: December 11, 2001
    Assignee: NSK Ltd.
    Inventors: Takashi Imanishi, Nobuo Goto, Makoto Fujinami, Hiroshi Kato, Nobuaki Mitamura, Hiroyuki Itoh, Seiji Higuchi, Hiroshi Fukushima
  • Publication number: 20010046921
    Abstract: A toroidal type continuously variable transmission, includes: at least one pair of disks concentrically disposed on each other and rotatably supported independent from each other; a trunnion swingable about a pivot shaft; a displacement shaft including a support shaft portion and a pivot shaft portion that are parallel and eccentric to each other, the support shaft portion rotatably supported to the circular hole of the trunnion through a radial bearing, the pivot shaft portion being protruded from an inner surface of the middle portion of said trunnion; a power roller nipped between the concave surfaces of the pair of disks while being rotatably supported on an outer circumferential surface of the pivot shaft portion; and a thrust bearings located between the power roller and the inner surface of the middle portion of the trunnions. An eccentric quantity of the displacement shaft being a distance between the support shaft portion and the pivot shaft portion is within a range from 5 mm to 15 mm.
    Type: Application
    Filed: June 22, 2001
    Publication date: November 29, 2001
    Applicant: NSK LTD.
    Inventors: Takashi Imanishi, Nobuo Goto, Makoto Fujinami, Hiroshi Kato, Nobuaki Mitamura, Hiroyuki Itoh, Seiji Higuchi, Hiroshi Fukushima
  • Patent number: 6210542
    Abstract: A substrate 2 is autorotatably installed in a vacuum chamber 1 at an upper part thereof. MgF2 granules 3 as a film source material are put in a quartz boat 4 and mounted on a magnetron cathode 5. The magnetron cathode 5 is connected through a matching box 6 to a 13.56 MHz radio frequency power source 7. Cooling water 8 for holding the temperature of the magnetron cathode 5 constant flows on a lower face of the magnetron cathode 5. A side face of the vacuum chamber 1 is provided with gas introduction ports 9, 10 for introducing gas in the vacuum chamber 1. A shutter 11 is placed between the magnetron cathode 5 and the substrate 2. This structure provides a process enabling forming a thin film at a high speed by sputtering, especially, a high speed sputtering process enabling forming a thin fluoride film free of light absorption in a high speed by sputtering.
    Type: Grant
    Filed: November 4, 1998
    Date of Patent: April 3, 2001
    Assignee: Olympus Optical Co., Ltd.
    Inventors: Ken Kawamata, Nobuaki Mitamura
  • Patent number: 6196946
    Abstract: A power roller of a power roller bearing in a half-toroidal type continuously variable transmission is manufactured as follows. In step S1, a work used as material is heated up to a temperature suitable for forging. In step S2, the work is pressed by using a first die set, with its end face being held. In step S3, the work is forged by using a second die set. The work is formed into a work having a curved face corresponding to a traction surface, a hole corresponding to a center hole, and a recess corresponding to a raceway groove. In step S4, the work is punched by using a third die set. In step S5, the work is subjected to a cutting process and a heating process, thereby obtaining the power roller.
    Type: Grant
    Filed: January 21, 1999
    Date of Patent: March 6, 2001
    Assignee: NSK Ltd.
    Inventors: Hiroyuki Sawai, Takafumi Kuwano, Nobuo Gotou, Takashi Imanishi, Nobuaki Mitamura
  • Patent number: 6176806
    Abstract: A cam disk for use in a loading cam mechanism of a toroidal type continuously variable transmission comprises a first projecting portion, a second projecting portion, a flange portion, a cam surface, a bearing raceway and a corner section. The cam disk has metal flows along the cam surface, metal flows along a surface of the raceway, and metal flows along a surface of the corner section. To produce the cam disk, material is shaped into a predetermined form through a first forging step using a first die unit, a second forging step using a second die unit, a third forging step using a third die unit, a finishing step, etc. The metal flows are also formed in these steps.
    Type: Grant
    Filed: July 7, 1999
    Date of Patent: January 23, 2001
    Assignee: NSK Ltd.
    Inventors: Kiyoshi Okubo, Hiroyuki Itoh, Nobuaki Mitamura, Nobuo Goto, Makoto Fujinami, Hiroshi Kato, Takashi Imanishi
  • Patent number: 6174085
    Abstract: A linear guide bearing device includes a rail, a bearing supported by the rail and rectilinearly movable along the axial direction of the rail, and rolling members interposed between the rail and the bearing to roll along with motion of the bearing. At least one of the rail and the bearing is made of induction-hardened steel including 0.6 to 0.9 wt % of carbon, 0.05 to 0.25 wt % of silicon, 0.3 to 0.9 wt % of manganese, 0.1 to 0.5 wt % of chromium, 0.2 to 1.0 wt % of molybdenum, and residual portion as iron and unavoidable impurities, and the induction-hardened steel has a total content of carbon, manganese, and molybdenum, which satisfies predetermined inequalities.
    Type: Grant
    Filed: January 5, 1999
    Date of Patent: January 16, 2001
    Assignee: NSK Ltd.
    Inventors: Tomonobu Yoshikawa, Nobuaki Mitamura
  • Patent number: 6174258
    Abstract: There is provided a trunnion for a toroidal continuously variable transmission in which the material is strengthened against the wear and plastic deformation of a trunnion. The trunnion includes a base portion having a body portion, which connects and supports a base end portion of a displacement shaft at a surface intermediate portion, and a pair of plate portions, in which an edge apart from the body portion is a tip end edge, and a pair of axis (shaft) portions protruding from the outside surfaces of the plate portions in opposite directions to each other. The toroidal continuously variable transmission is characterized in that at least the rolling surface of a radial needle bearing for supporting the tilted rotation of the trunnion has a hardness not lower than HRC55, and a core portion has a hardness not lower than HRC20 and not higher than HRC45.
    Type: Grant
    Filed: October 29, 1998
    Date of Patent: January 16, 2001
    Assignee: NSK Ltd.
    Inventors: Takashi Imanishi, Nobuo Goto, Hiroshi Kato, Nobuaki Mitamura
  • Patent number: 6174257
    Abstract: An outer race of a thrust ball bearing supporting a thrust load applied to a power roller is rotatably supported around a displacement shaft. A portion in which the contact pressure between an outer race track and the rolling surface of a rolling member is high changes so that the fatigue of the outer race track does not progress locally. Also, the power roller and the outer race are subjected to predetermined treatment and working. Irrespective of a great thrust load applied during operation, stress is alleviated and the lubricating property of the portion of contact is made good to thereby prevent cracks or early wear from occurring.
    Type: Grant
    Filed: July 1, 1998
    Date of Patent: January 16, 2001
    Assignee: NSK Ltd.
    Inventors: Takashi Imanishi, Nobuaki Mitamura, Nobuo Goto, Makoto Fujinami, Hiroshi Kato
  • Patent number: 6171414
    Abstract: A rolling bearing comprises races including an inner race and an outer race formed of an alloy steel material; and a plurality of rolling elements formed of a ceramic material and interposed between the inner race and the outer race in such a manner as to be capable of rolling, wherein at least one of the inner race and the outer race is formed of an alloy steel containing 0.7-1.5 wt. % Si, 0.5-2.0 wt. % Cr, and 0.5-2.0 wt. % Mo in a steel, and is subjected to carbonitriding treatment on the surface of the alloy steel material. The rolling bearing excels in the durability and heat resistance even if it is used in a high-temperature high-speed environment, and does not cause a noise fault.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: January 9, 2001
    Assignees: NSK Ltd., Ishikawajima-Harima Heavy Industries Co., Ltd.
    Inventors: Nobuaki Mitamura, Kazuo Sekino, Takaaki Koike, Yukio Takahashi, Mikio Yamaguchi
  • Patent number: 6165100
    Abstract: At least one of input/output disks, a power roller and a cam disk of a toroidal type continuously variable transmission is formed of a high-cleanness steel in which a size of a maximum inclusion is estimated by the following extremum statistical process. In step S1, a plane including a central line of the high-cleanness steel is cut out in a direction of rolling of the high-cleanness steel. In step S2, a portion d of the cut-out cross-section, which is defined by 40% of a diameter D in the vicinity of the central line, is used as a to-be-tested surface. In step S3, a test reference area S.sub.0 is set at an area not less than 300 mm.sup.2 within the to-be-tested surface, and a root of an area of the maximum inclusion is measured five times or more. In step S4, a maximum inclusion distribution straight line is obtained. In step S5, the root, that is, the size of the area of the maximum inclusion within an estimation area S is estimated.
    Type: Grant
    Filed: November 6, 1998
    Date of Patent: December 26, 2000
    Assignees: NSK Ltd., Sanyo Special Steel Co., Ltd.
    Inventors: Nobuaki Mitamura, Tomonobu Yoshikawa, Yasuo Murakami