Patents by Inventor Yoshiyuki Yasutomi
Yoshiyuki Yasutomi 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: 20040197738Abstract: The present invention provides a dental ceramic frame (10, 20, 30, 50) which is superior in terms of mechanical strength characteristics compared with conventional bridge-shaped ceramic frames that have glass joining layers or frames consisting of porous ceramics impregnated with glass.Type: ApplicationFiled: January 27, 2004Publication date: October 7, 2004Inventors: Kiyoko Ban, Toshio Sakakibara, Yoshiyuki Yasutomi, Yorinobu Takigawa, Hiroya Abe
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Patent number: 5876659Abstract: Fiber bundle reinforced composite material useful for various high temperature structural members having excellent strength, toughness and resistance to oxidation and a process for producing the same. The fiber bundle reinforced composite material is reinforced with fiber bundles each having a plurality of continuous inorganic fibers bundled with medium such as carbon, being oriented in one, two or three directions, or randomly in the matrix which is reinforced with nano-sized particles precipitated. The fiber bundle reinforced composite material has a desired orientation of fibers and enables production of fiber bundle reinforced composite members having excellent strength and toughness.Type: GrantFiled: July 24, 1997Date of Patent: March 2, 1999Assignee: Hitachi, Ltd.Inventors: Yoshiyuki Yasutomi, Shigeru Kikuchi, Yukio Saito, Kunihiro Maeda
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Patent number: 5851675Abstract: An apparatus comprising a plurality of sliding members, at least one of the sliding members being a self-lubricating-function sliding member characterized by containing a precursor compound which produces a solid-lubricating compound during sliding by reacting with an atmosphere in which the sliding member is used or a component of a material with which the sliding member is in sliding contact.Type: GrantFiled: May 30, 1995Date of Patent: December 22, 1998Assignee: Hitachi, Ltd.Inventors: Tomohito Oyagi, Mitsuo Nakagawa, Junji Sakai, Yoshiyuki Yasutomi, Takahiko Okouchi
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Patent number: 5736198Abstract: The surface of a member formed of at least one kind of ceramics, metals and C/C composites, is covered with an outermost surface oxide covering layer having a stability against the environment in the atmospheric air at 1500.degree. C.; and a self-recoverable layer as an intermediate layer formed between the outermost surface oxide covering layer and the surface of the member. The self-recoverable layer has an oxidizing rate greater than that of the outermost surface covering layer for recovering cracks generated on the outermost surface covering layer, and a compound produced by the self-recoverable layer has the same phase as in the outermost surface covering layer. To achieve the optimum self-recovering function at high temperatures, the outermost surface oxide covering layer may be made of a stable oxide having a vapor pressure of 1.times.10.sup.-4 /m.sup.2 or less in the atmospheric air at 1500.degree. C.Type: GrantFiled: November 13, 1995Date of Patent: April 7, 1998Assignee: Hitachi, Ltd.Inventors: Yoshiyuki Yasutomi, Shigeru Kikuchi, Yukio Saito, Mitsuo Nakagawa, Motoyuki Miyata
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Patent number: 5625153Abstract: A method of estimating non-destructively the life expectancy of ceramic members, at least a surface layer of which is made of ceramics, is disclosed. The method comprises measuring a variation in at least one of physical characteristics of said ceramic members including color, grain size, electroconductivity and Young's modulus and estimating the life expectancy of the ceramic members on the basis of the predetermined relationship between the life of said ceramics and the physical characteristics. The method is excellent in estimation of the life expectancy of ceramic members of gas turbines or nuclear fusion reactor since the life expectancy of the members to be inspected can easily be estimated in a short time without fracturing the members.Type: GrantFiled: December 18, 1995Date of Patent: April 29, 1997Assignee: Hitachi, Ltd.Inventors: Yuichi Sawai, Yoshiyuki Yasutomi, Motoyuki Miyata, Hideki Tamaki, Katsuo Wada
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Patent number: 5581039Abstract: To provide diagnosis of service life and maintenance requirements, a sintered ceramic body which in use is subjected to stress and undergoes change with time as a result of the stress is provided with an electrically conductive element in contact with the sintered ceramic material The element has a measurable electrical resistance which increases in dependence on the change of the ceramic body. This permits information to be obtained about said change of said body. Measuring means for the electrical resistance is connected to the conductive element. The electrically conductive element as seen in cross-section, may comprise a bundle of elongate members such as fibers or whiskers.Type: GrantFiled: November 10, 1994Date of Patent: December 3, 1996Assignee: Hitachi, Ltd.Inventors: Yoshiyuki Yasutomi, Motoyuki Miyata, Shigeru Kikuchi, Yukio Saito
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Patent number: 5403674Abstract: The invention provides a conductor comprising a reaction-sintered body of a conductive nitride produced from a powder of at least one metal selected from Ti, Zr, V, Nb, Ta, Cr, Ce, Co, Mn, Hf, W, Mo, Fe, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Yb, Lu, Th and Ni, and a process for producing such conductor by heating a molding containing a metal powder in a nitriding gaseous atmosphere containing no CO gas.Type: GrantFiled: September 9, 1993Date of Patent: April 4, 1995Assignee: Hitachi, Ltd.Inventors: Yoshiyuki Yasutomi, Tadahiko Miyoshi, Masahisa Sobue, Nobuyuki Yamashita, Hiroshi Nagase, Kiyohiko Tanno, Shoji Arimoto, Fumio Jooraku
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Patent number: 5378417Abstract: Disclosed is a ceramic composite which comprises particles of at least one inorganic compound selected from the group consisting of a carbide, a nitride, an oxide, a boride, a silicide and an oxy-nitride and particles and whiskers of Si.sub.3 N.sub.4, Si.sub.2 N.sub.2 O or SiO.sub.2. This ceramic composite is small in volume change on sintering, and provides heat resistance. In addition, the composite can absorb thermal shock by its voids. It can be used in association with ceramic heaters, current collectors, commutators for starter motors and alternators, and in other areas.Type: GrantFiled: September 22, 1989Date of Patent: January 3, 1995Assignee: Hitachi, Ltd.Inventors: Yoshiyuki Yasutomi, Kousuke Nakamura, Hideki Kita, Masahisa Sobue
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Patent number: 5316987Abstract: Disclosed is a ceramic composite which comprises particles of at least one inorganic compound selected from the group consisting of a carbide, a nitride, an oxide, a boride, a silicide and an oxy-nitride and particles and whiskers of Si.sub.3 N.sub.4, Si.sub.2 N.sub.2 O or SiO.sub.2. This ceramic composite is small in volume change on sintering, and provides heat resistance. In addition, the composite can absorb thermal shock by its voids. It can be used in association with ceramic heaters, current collectors, commutators for starter motors and alternators, and in other areas.Type: GrantFiled: March 30, 1992Date of Patent: May 31, 1994Assignee: Hitachi, Ltd.Inventors: Yoshiyuki Yasutomi, Kousuke Nakamura, Hideki Kita, Masahisa Sobue
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Patent number: 5271871Abstract: The invention provides a conductor comprising a reaction-sintered body of a conductive nitride produced from a powder of at least one metal selected from Ti, Zr, V, Nb, Ta, Cr, Ce, Co, Mn, Hf, W, Mo, Fe, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Yb, Lu, Th and Ni, and a process for producing such conductor by heating a molding containing a metal powder in a nitriding gaseous atmosphere containing no CO gas.Type: GrantFiled: September 3, 1991Date of Patent: December 21, 1993Assignee: Hitachi, Ltd.Inventors: Yoshiyuki Yasutomi, Tadahiko Miyoshi, Masahisa Sobue, Nobuyuki Yamashita, Hiroshi Nagase, Kiyohiko Tanno, Shoji Arimoto, Fumio Jooraku
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Patent number: 5252273Abstract: A casting method for manufacturing various types of ceramics products having an intricate configuration and a partly diversified wall thickness, such as compressor scroll blade and a screw rotor, by casting a slurry including ceramics, etc. in a mold, includes an arrangement wherein the mold is partly or entirely formed of a flexible gel material which can be melted by heating at a temperature lower than the boiling point of the dispersion medium, whereby the stresses generated when molding the product can be mitigated. Thus, the molding of a product having a high level of dimensional accuracy can be carried out with ease.Type: GrantFiled: May 23, 1991Date of Patent: October 12, 1993Assignee: Hitachi, Ltd.Inventors: Junji Sakai, Masahisa Sobue, Yoshiyuki Yasutomi
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Patent number: 5200373Abstract: The present invention is a composite ceramic structure having a porosity of 5 to 40% by volume comprising particles selected from the group consisting of grains and whiskers of at least one inorganic compound AB, where B is oxygen, nitrogen or carbon and A is any metal so the difference in electronegativity between A and B is less than 1.7; or particles selected from the group consisting of grains and whiskers of an inorganic compound, where there is a difference of 1.7 and higher between the components, and having layers of the inorganic compound AB formed on the surfaces of the particles. The particles are bonded together by silicon nitride particles having an average particle size of less than 0.2 micron.Type: GrantFiled: March 18, 1991Date of Patent: April 6, 1993Assignee: Hitachi, Ltd.Inventors: Yoshiyuki Yasutomi, Seiji Watahiki, Junji Sakai, Akio Chiba, Tadahiko Miyoshi, Masahisa Sobue
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Patent number: 5130055Abstract: Disclosed is a ceramic composite which comprises particles of at least one inorganic compound selected from the group consisting of a carbide, a nitride, an oxide, a boride, a silicide and an oxy-nitride and particles and whiskers of Si.sub.3 N.sub.4, Si.sub.2 N.sub.2 O or SiO.sub.2. This ceramic composite is small in volume change on sintering and superior in heat resistance and besides can absorb thermal shock by its voids. It can be used as ceramic heaters, current collectors, commutators for starter motor and alternator and the like.Type: GrantFiled: March 26, 1990Date of Patent: July 14, 1992Inventors: Yoshiyuki Yasutomi, Kousuke Nakamura, Hideki Kita, Masahisa Sobue
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Patent number: 5085806Abstract: The invention provides a conductor comprising a reaction-sintered body of a conductive nitride produced from a powder of at least one metal selected from Ti, Zr, V, Nb, Ta, Cr, Ce, Co, Mn, Hf, W, Mo, Fe, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Yb, Lu, Th and Ni, and a process for producing such conductor by heating a molding containing a metal powder in a nitriding gaseous atmosphere containing no CO gas.Type: GrantFiled: March 6, 1989Date of Patent: February 4, 1992Assignee: Hitachi, Ltd.Inventors: Yoshiyuki Yasutomi, Tadahiko Miyoshi, Masahisa Sobue, Nobuyuki Yamashita, Hiroshi Nagase, Kiyohiko Tanno, Shoji Arimoto, Fumio Jooraku
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Patent number: 5045922Abstract: An installation structure of integrated circuit devices, in which two or more types of integrated circuit devices of different base materials are installed onto the same installation substrate. Since the installation structure has a construction according to different characteristics such as a thermal conductivity, heat generation amount, thermal expansion coefficient and the like of the integrated circuit devices made of different materials, the reliability of each device and its connection and the reduction of the costs required for the cooling method can be presented.Type: GrantFiled: September 17, 1990Date of Patent: September 3, 1991Assignee: Hitachi, Ltd.Inventors: Hironori Kodama, Satoru Ogihara, Hideo Arakawa, Hirokazu Inoue, Yoshiyuki Yasutomi, Tadahiko Miyoshi
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Patent number: 4923829Abstract: Composite ceramic materials and a method of the same are disclosed, in which a ceramic material mainly containing silicon nitride, and at least one compound selected from a group consisting of nitrides, carbides, borides, silicides, oxides and oxynitrides of elements belonging to IIIa, IIIb, IVa, IBb, Va, VIa and VIII are combined to form a sintered body, and particles and whiskers of the ceramic material and compound are interlocked with each other and fixed so that the sintered body has a porosity of 5 to 30%. In the above composite ceramics, the particle of the compound are coupled with each other through the whisker or particle of the ceramic material. Accordingly, the composite ceramics are small in charge rate of size due to sintering, and are excellent in tenacity, heat resisting property and thermal shock resisting property. Further, the resistivity of the sintered body can be varied by changing the mixture ratio of ceramic material and compound.Type: GrantFiled: February 17, 1989Date of Patent: May 8, 1990Assignee: Hitachi, Ltd.Inventors: Yoshiyuki Yasutomi, Yasuo Matsushita, Kousuke Nakamura