Patents by Inventor Masahisa Sobue
Masahisa Sobue 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: 7031166Abstract: A silicon nitride sintered body comprising Mg and at least one rare earth element selected from the group consisting of La, Y, Gd and Yb, the total oxide-converted content of the above elements being 0.6–7 weight %, with Mg converted to MgO and rare earth elements converted to rare earth oxides RExOy. The silicon nitride sintered body is produced by mixing 1–50 parts by weight of a first silicon nitride powder having a ?-particle ratio of 30–100%, an oxygen content of 0.5 weight % or less, an average particle size of 0.2–10 ?m, and an aspect ratio of 10 or less, with 99–50 parts by weight of ?-silicon nitride powder having an average particle size of 0.2–4 ?m; and sintering the resultant mixture at a temperature of 1,800° C. or higher and pressure of 5 atm or more in a nitrogen atmosphere.Type: GrantFiled: November 30, 2004Date of Patent: April 18, 2006Assignee: Hitachi Metals, Ltd.Inventors: Hisayuki Imamura, Shigeyuki Hamayoshi, Tsunehiro Kawata, Masahisa Sobue
-
Publication number: 20050094381Abstract: A silicon nitride sintered body comprising Mg and at least one rare earth element selected from the group consisting of La, Y, Gd and Yb, the total oxide-converted content of the above elements being 0.6-7 weight %, with Mg converted to MgO and rare earth elements converted to rare earth oxides RExOy. The silicon nitride sintered body is produced by mixing 1-50 parts by weight of a first silicon nitride powder having a ?-particle ratio of 30-100%, an oxygen content of 0.5 weight % or less, an average particle size of 0.2-10 ?m, and an aspect ratio of 10 or less, with 99-50 parts by weight of ?-silicon nitride powder having an average particle size of 0.2-4 ?m; and sintering the resultant mixture at a temperature of 1,800° C. or higher and pressure of 5 atm or more in a nitrogen atmosphere.Type: ApplicationFiled: November 30, 2004Publication date: May 5, 2005Inventors: Hisayuki Imamura, Shigeyuki Hamayoshi, Tsunehiro Kawata, Masahisa Sobue
-
Patent number: 6846765Abstract: A silicon nitride sintered body comprising Mg and at least one rare earth element selected from the group consisting of La, Y, Gd and Yb, the total oxide-converted content of the above elements being 0.6-7 weight %, with Mg converted to MgO and rare earth elements converted to rare earth oxides RExOy. The silicon nitride sintered body is produced by mixing 1-50 parts by weight of a first silicon nitride powder having a particle ratio of 30-100%, an oxygen content of 0.5 weight % or less, an average particle size of 0.2-10 ?m, and an aspect ratio of 10 or less, with 99?50 parts by weight of ?-silicon nitride powder having an average particle size of 0.2-4 ?m; and sintering the resultant mixture at a temperature of 1,800° C. or higher and pressure of 5 atm or more in a nitrogen atmosphere.Type: GrantFiled: September 20, 2001Date of Patent: January 25, 2005Assignee: Hitachi Metals, Ltd.Inventors: Hisayuki Imamura, Shigeyuki Hamayoshi, Tsunehiro Kawata, Masahisa Sobue
-
Publication number: 20020164475Abstract: A silicon nitride sintered body comprising Mg and at least one rare earth element selected from the group consisting of La, Y, Gd and Yb, the total oxide-converted content of the above elements being 0.6-7 weight %, with Mg converted to MgO and rare earth elements converted to rare earth oxides RExOy. The silicon nitride sintered body is produced by mixing 1-50 parts by weight of a first silicon nitride powder having a &bgr;-particle ratio of 30-100%, an oxygen content of 0.5 weight % or less, an average particle size of 0.2-10 &mgr;m, and an aspect ratio of 10 or less, with 99-50 parts by weight of &agr;-silicon nitride powder having an average particle size of 0.2-4 &mgr;m; and sintering the resultant mixture at a temperature of 1,800° C. or higher and pressure of 5 atm or more in a nitrogen atmosphere.Type: ApplicationFiled: September 20, 2001Publication date: November 7, 2002Applicant: HITACHI METALS, LTD.Inventors: Hisayuki Imamura, Shigeyuki Hamayoshi, Tsunehiro Kawata, Masahisa Sobue
-
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
-
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
-
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
-
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
-
Patent number: 5266860Abstract: A commutator has a central support supporting a plurality of conductive segments separated by a plurality of insulative segments. In addition to providing an insulative function between the conductive segments, the dielectric constant, the area, and the thickness of the insulative segments are chosen so that they provide a capacitive effect, which capacitive effect suppresses current peaks during operation of the commutator. Preferably, the dielectric constant is greater than 10. The central support may include a metal shaft and an insulating ring, which insulating ring is preferably of material with a lower dielectric constant thereby to suppress-shorting between the shaft and the conductive segments. It is particularly advantageous if the conductive and insulative segments are of ceramics material since this provides good wear resistance. In further alternatives, capacitors are formed between the conductive segments by rings or other bodies of insulative materials of a suitably high dielectric constant.Type: GrantFiled: March 17, 1992Date of Patent: November 30, 1993Assignee: Hitachi, Ltd.Inventors: Akio Chiba, Masahisa Sobue, Kazuo Tahara, Nobuyuki Yamashita, Shun Suzuki
-
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
-
Patent number: 5208502Abstract: Ceramics material are not resistant to tensile force, though they are resistant to compression force. Therefore, ceramics materials, when used as the material of a commutator of an electric rotary machine, tends to be cracked and broken due to tensile stress generated in the inner peripheral portion of the commutator when the latter is press-fitted on the rotor shaft of the machine. The invention is aimed at obviating the above-described problem, so as to make it possible to produce a sliding current collector of an electric rotary machine from a ceramics material. To this end, according to the invention, an annular gap is formed between the inner peripheral surface of the ceramics commutator and the other peripheral surface of the rotary shaft and the gap is filled with a resin such as a thermosetting resin which is then thermally set to form a resin layer by which the commutator is bonded to the rotor shaft.Type: GrantFiled: February 27, 1992Date of Patent: May 4, 1993Assignees: Hitachi, Ltd., Hitachi Koki Co., Ltd.Inventors: Nobuyuki Yamashita, Kazuo Tahara, Akio Chiba, Masahisa Sobue, Toshimi Abukawa, Shin'ichi Sakamoto, Shun Suzuki
-
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
-
Patent number: 5138221Abstract: The present invention relates to an inorganically insulated heater having a long life for use in air flow sensors, cathode ray tube cathode heaters etc., wherein the distribution of inorganic insulating particles of the whole insulating layer is made uniform and thereby the development of cracks and the like in the insulating layer is reduced and breaking of wire and dielectric breakdown occur with difficulty even at high temperatures and under strong vibrations.Type: GrantFiled: June 28, 1990Date of Patent: August 11, 1992Assignee: Hitachi, Ltd.Inventors: Toshiaki Arato, Toshiaki Narisawa, Masahisa Sobue, Nobuyuki Koganezawa
-
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
-
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
-
Patent number: 4941251Abstract: A roller for rolling mill comprising an entirely non-metallic sintered body composed principally of at least one material selected from silicon carbide, silicon nitride, sialon, alumina and zirconia and having a relative density which is at least 96% of the theoretical density, the roller having an initial crown in the range of -300 .mu.m to +300 .mu.m, is provided. This roller for rolling mill has a high hardness and high wear resistance and can be used as a work roll.Type: GrantFiled: June 2, 1989Date of Patent: July 17, 1990Assignee: Hitachi, Ltd.Inventors: Masahisa Sobue, Sensuke Okada, Kimihiko Akahori, Keiichi Kuniya, Toshimi Sasaki, Toshiyuki Kajiwara, Tomoaki Kimura, Mitsuo Nihei
-
Patent number: 4839949Abstract: A roller for rolling mill comprising an entirely non-metallic sintered body composed principally of at least one material selected from silicon carbide, silicon nitride, sialon, alumina and zirconia and having a relative density which is at least 96% of the theoretical density of the sintered body, the roller having an initial crown in the range of -300 .mu.m to +300 .mu.m, is provided. This roller for rolling mill has a high hardness and high wear resistance and can be used as a work roll.Type: GrantFiled: May 12, 1987Date of Patent: June 20, 1989Assignee: Hitachi, Ltd.Inventors: Masahisa Sobue, Sensuke Okada, Kimihiko Akahori, Keiichi Kuniya, Toshimi Sasaki, Toshiyuki Kajiwara, Tomoaki Kimura, Mitsuo Nihei