Patents by Inventor Yasuhito Tanaka

Yasuhito Tanaka 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: 6116393
    Abstract: In an annular space between a pulley and a shaft body disposed coaxially with each other, a one-way clutch is interposed in an intermediate range in an axial direction and rolling bearings are disposed on both sides in the axial direction of the one-way clutch. A tightening distance for fitting between the one-way clutch and pulley is set to be smaller than that between the rolling bearing and pulley. Due to this structure, in a condition in which an excessive radial load acts upon the pulley, that radial load acts on not the one-way clutch but the rolling bearings on both sides thereof, so that a clutch operation of the one-way clutch can be carried out stably.
    Type: Grant
    Filed: September 23, 1998
    Date of Patent: September 12, 2000
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Junya Ooitsu, Yasuhito Tanaka, Hajime Tazumi, Yoshitaka Nakagawa
  • Patent number: 6095301
    Abstract: A pulley unit comprising two inner and outer annular bodies disposed coaxially and a one-way clutch interposed in an annular space between both the annular bodies, both ends in the axial direction of the annular space being sealed by a seal and at least the sealed portion of at least one seal being hidden by an annular member mounted to the inner annular body. By this structure, the sealed portion by the seal is protected from a direct splash of water, so that invasion of water through the sealed portion becomes unlikely to occur.
    Type: Grant
    Filed: September 22, 1998
    Date of Patent: August 1, 2000
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Hideki Fujiwara, Yasuhito Tanaka, Yoshitaka Nakagawa, Hajime Tazumi, Junya Ooitsu
  • Patent number: 6093991
    Abstract: An alternator pulley includes a driving member driven and rotated via a belt from an output shaft of an engine. A driving member is disposed on an inner surface of the driving member and a one-way clutch is interposed between the driving and driven member. The one-way clutch includes rollers capable of rolling in a locked side direction along which a rotating power of the driving member is transmitted to the driven member or a free side direction along which the rotating powder is interrupted. Depending on a relative speed difference between the driving member and the driven member, the rollers are biased for pressing in the locked side direction and a torque value of the pressing is set preferably to less than 4 Nm.
    Type: Grant
    Filed: January 21, 1998
    Date of Patent: July 25, 2000
    Assignee: Koyo Seiko Co., Ltd.
    Inventor: Yasuhito Tanaka
  • Patent number: 5879254
    Abstract: A pulley has a hub fixed to a rotating shaft. An outer wheel is disposed on the outer periphery of the hub and around which a belt is suspended, and a unidirectional clutch is interposed between the hub and the outer wheel. A cam face for forming a wedged space of the unidirectional clutch is formed at the inside of the pulley, whereby the unidirectional clutch is switched between a free state and a locked state through the rotational variation of the hub which rotates integrally with the rotating shaft to reduce the transmission of the rotational variation from the hub to the outer wheel. Further, the unidirectional clutch can operate stably without suffering the effect of the rotational centrifugal force.
    Type: Grant
    Filed: August 5, 1997
    Date of Patent: March 9, 1999
    Assignee: Koyo Seiko Co., Ltd.
    Inventor: Yasuhito Tanaka
  • Patent number: 4965263
    Abstract: This invention relates to pyridazinone derivatives of the general formula: ##STR1## [wherein R.sup.1 stands for a hydrogen atom or a lower alkyl group; R.sup.2 for a hydrogen atom or a lower alkyl group; and A for (i) a ring selected from a benzene ring, a furan ring, a thiophene ring and a pyridine ring (on which ring 1-3 substituents or atoms selected from amino groups, nitro groups, lower alkanoylamino groups, hydroxyl groups, lower alkanoyloxy groups, sulfamoyl groups and halogen atoms may be present), or (ii) a grouping of the formula: ##STR2## (wherein R.sup.3 stands for a hydrogen atom, a lower alkyl group, a phenyl(lower)alkyl, a hydroxyphenyl(lower)alkyl group, a lower alkylmercapto(lower)alkyl group, a benzylmercapto(lower)alkyl group, a guanidino(lower)alkyl group, a nitroguanidino(lower)alkyl group, an indolyl(lower)alkyl group, a carbamoyl(lower)alkyl group or a carboxy(lower)alkyl group, R.sup.4 for a hydrogen atom or a lower alkyl group, R.sup.
    Type: Grant
    Filed: February 14, 1989
    Date of Patent: October 23, 1990
    Assignee: Mitsui Toatsu Kagaku Kabushiki Kaisha
    Inventors: Takashi Nishina, Joji Kamiya, Yasuhito Tanaka, Tsutomu Katakami, Nobuyuki Fukazawa, Hajime Iizuka, Takuo Nakano
  • Patent number: 4639451
    Abstract: This invention relates to pyridazinone derivatives of the general formula: ##STR1## [wherein R.sup.1 stands for a hydrogen atom or a lower alkyl group; R.sup.2 for a hydrogen atom or a lower alkyl group; and A for (i) a ring selected from a benzene ring, a furan ring, a thiophene ring and a pyridine ring (on which ring 1-3 substituents or atoms selected from amino groups, nitro groups, lower alkanoylamino groups, hydroxyl groups, lower alkanoyloxy groups, sulfamoyl groups and halogen atoms may be present), or (ii) a grouping of the formula: ##STR2## (wherein R.sup.3 stands for a hydrogen atom, a lower alkyl group, a phenyl(lower)alkyl, a hydroxyphenyl(lower)alkyl group, a lower alkylmercapto(lower)alkyl group, a benzylmercapto(lower)alkyl group, a guanidino(lower)alkyl group, a nitroguanidino(lower)alkyl group, an indolyl(lower)alkyl group, a carbamoyl(lower)alkyl group or a carboxy(lower)alkyl group, R.sup.4 for a hydrogen atom or a lower alkyl group, R.sup.
    Type: Grant
    Filed: June 3, 1983
    Date of Patent: January 27, 1987
    Assignee: Mitsui Toatsu Kagaku-Kabushiki Kaisha
    Inventors: Tsutomu Katakami, Nobuyuki Fukazawa, Hajime Iizuka, Takashi Nishina, Joji Kamiya, Yasuhito Tanaka, Takuo Nakano
  • Patent number: 4523011
    Abstract: 6-(Substituted phenyl)-4,5-dihydro-3(2H)-pyridazinone compounds possessing strong platelet aggregation inhibiting activity and blood pressure depressing activity, having the general formula: ##STR1## wherein R.sup.1 is hydrogen or lower alkyl; R.sup.2 is hydrogen, lower alkyl, lower alkylthio or the grouping R.sup.5 --NH-- where R.sup.5 is lower alkyl; R.sup.3 is phenyl, pyridyl, benzyl, lower alkyl or a substituted phenyl group carrying at any desired position on the benzene ring thereof the grouping: ##STR2## where R.sup.1 has the same meaning as given above; R.sup.4 is hydrogen or halogen; n is 0 or 1; and when both R.sup.2 and R.sup.3 are lower alkyl groups, R.sup.2 and R.sup.3 may be combined together with the bridging member ##STR3## between them to form the structure: ##STR4## where m is 2 or 3, as well as physiologically acceptable acid-addition salts thereof, and processes for preparing them.
    Type: Grant
    Filed: March 28, 1984
    Date of Patent: June 11, 1985
    Assignee: Mitsui Toatsu Kagaku Kabushiki Kaisha
    Inventors: Tsutomu Katakami, Nobuyuki Fukazawa, Hajime Iizuka, Takashi Nishina, Joji Kamiya, Yasuhito Tanaka, Takuo Nakano
  • Patent number: 4521415
    Abstract: 6-(Substituted phenyl)-4,5-dihydro-3(2H)-pyridazinone compounds possessing strong platelet aggregation inhibiting activity and blood pressure depressing activity, having the general formula: ##STR1## wherein R.sup.1 is hydrogen or lower alkyl; R.sup.2 is hydrogen, lower alkyl, lower alkylthio or the grouping R.sup.5 --NH-- where R.sup.5 is lower alkyl; R.sup.3 is phenyl, pyridyl, benzyl, lower alkyl or a substituted phenyl group carrying at any desired position on the benzene ring thereof the grouping: ##STR2## where R.sup.1 has the same meaning as given above; R.sup.4 is hydrogen or halogen; n is 0 or 1; and when both R.sup.2 and R.sup.3 are lower alkyl groups, R.sup.2 and R.sup.3 may be combined together with the bridging member ##STR3## where m is 2 or 3, as well as physiologically acceptable acid-addition salts thereof, and processes for preparing them.
    Type: Grant
    Filed: December 28, 1982
    Date of Patent: June 4, 1985
    Assignee: Mitsui Toatsu Kagaku Kabushiki Kaisha
    Inventors: Tsutomu Katakami, Nobuyuki Fukazawa, Hajime Iizuka, Takashi Nishina, Joji Kamiya, Yasuhito Tanaka, Takuo Nakano