Patents by Inventor Kohji Maki
Kohji Maki 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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Patent number: 7157912Abstract: At least one superconducting shim coil is wound around a cylinder member disposed approximately coaxially with a group of superconducting main coils, and the positions in the winding center locus in an axial direction change approximately in accordance with a function where a sine or cosine function with a cycle of (360/m) degrees (m; an integer of one or more) in a circumferential direction is mixed with a sine or cosine function with a cycle of (360/(m+2)) degrees.Type: GrantFiled: June 27, 2005Date of Patent: January 2, 2007Assignee: Hitachi, Ltd.Inventors: Kohji Maki, Tsuyoshi Wakuda
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Patent number: 7141977Abstract: To access a measurement space located at the center of the magnet, an access port is provided in the direction of the magnet's axis, a clearance is provided in the coil winding portion, and another access port passes through the clearance so that a sample can be positioned perpendicularly to the coil axis. According to this configuration, an access port passing through the coil winding portion can be smaller than the access port passing through the coil axis, a sample is inserted from the access port, and a probe is inserted from the access port passing through the magnet axis, and thus the clearance can be minimized.Type: GrantFiled: April 2, 2004Date of Patent: November 28, 2006Assignee: Hitachi, Ltd.Inventors: Tsuyoshi Wakuda, Michiya Okada, Tomomi Kikuta, Kohji Maki, Hiroshi Morita, Shuichi Kido, Tomoo Chiba, Hideo Tsukamoto
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Patent number: 7138734Abstract: In order to reduce load supported by a support mechanism for supporting a movable part so as to prevent the movable part from moving in a horizontal direction when stress is generated thereon in the horizontal direction, there is provided a drive unit including a primary side having a magnetic body around which a coil is wound, and a secondary side having a plurality of permanent magnets, the primary side including magnetic poles and step portions provided on the magnetic poles. The width of each step portion is smaller than the width of each permanent magnet.Type: GrantFiled: May 10, 2005Date of Patent: November 21, 2006Assignee: Hitachi, Ltd.Inventors: Houng Joong Kim, Kohji Maki, Yasuo Morooka, Isamu Numata, Hisao Tadokoro, Takeo Morimoto, Yasunori Sannohe, Hiroshi Ueno, Hideki Shimane
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Patent number: 7093687Abstract: An angle-torque sensor has: a torque detection coil that detects a change in state quantity in a mechanism to detect a relative angle made between input axis and output axis of a torsion bar to be twisted by a torque; an angle detection coil that detects a change in state quantity in a mechanism to detect a rotation angle of a reduction axis which rotates with a rotation being transmitted from the input axis or output axis and being reduced by a reduction mechanism; a torque detection circuit that detects the relative angle from the output of the torque detection coil; and an angle detection circuit that detects the rotation angle from the output of the angle detection coil.Type: GrantFiled: April 7, 2005Date of Patent: August 22, 2006Assignee: Hitachi Cable, Ltd.Inventors: Ryoso Masaki, Satoru Kaneko, Kohji Maki, Ryoichi Menju
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Patent number: 7057327Abstract: A vehicular alternator is provided which can effectively utilize the magnetic flux of a permanent magnet disposed between claw-type magnetic poles and can improve an output of the alternator. The vehicular alternator comprises a rotor and a stator constituted by coiling stator windings over a stator core, the rotor comprising a pair of claw-type magnetic poles arranged in an opposed relation, a permanent magnet disposed between adjacent two of a plurality of claws provided on the pair of claw-type magnetic poles, and field windings coiled radially inward of the plurality of claws. Each of the plurality of claws of the rotor is formed to have a shape coming into contact with the whole of a magnetic pole surface of the permanent magnet.Type: GrantFiled: August 30, 2001Date of Patent: June 6, 2006Assignee: Hitachi, Ltd.Inventors: Hiroshi Kanazawa, Kenji Miyata, Kaoru Kawabata, Kohji Maki, Kazuo Tahara, Susumu Sasaki, Ryoichi Takahata
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Publication number: 20060109006Abstract: A magnet for an NMR an analyzer includes a superconductor coil which is operated under a permanent current mode so as to generate a magnetic field in a space surrounded by the superconductor coil, and which enables a sample to be inserted into a measurement space in the magnetic space for analization. The superconductor coil includes a first access port for enabling access to the measurement space and a second access port for enabling insertion of the sample into the measurement space in a direction different from a direction of the first access port. An effective diameter of the first access port is larger than an effective diameter of the second access port when the effective diameters of the first and second access ports are defined as a diameter of a cylinder that is insertable into the first and second access ports.Type: ApplicationFiled: January 12, 2006Publication date: May 25, 2006Inventors: Tsuyoshi Wakuda, Michiya Okada, Tomomi Kikuta, Kohji Maki, Hiroshi Morita, Shuichi Kido, Tomoo Chiba, Hideo Tsukamoto
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Patent number: 7049913Abstract: The present invention provides a superconductivity magnet apparatus for generating a uniform magnetic field suitable for NMR applications. The superconductivity magnet apparatus has an access port for allowing an access to the center of the magnetic field from an external position separated away from the center in a direction other than the axial direction of a split-type superconductivity electromagnet employed in the magnet apparatus. In the superconductivity magnet apparatus, a gap exists between first and second superconductivity coil blocks facing each other to form the split-type superconductivity electromagnet. To put it in detail, the access port allows an access to a measurement space at the center of the magnet by way of the gap. A configuration element of the magnet such as a coil bobbin is cut out for providing the access port. An area including a deficiency portion caused by the cutout portion or the like is filled up with a material having a relative magnetic permeability in the range 1.Type: GrantFiled: February 26, 2004Date of Patent: May 23, 2006Assignee: Hitachi, Ltd.Inventors: Tsuyoshi Wakuda, Kohji Maki, Mitsuyoshi Tsuchiya, Michiya Okada, Hideo Tsukamoto, Souji Kajiura, Shuichi Kido
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Publication number: 20060091736Abstract: The conventional linear drive apparatus has the problem that in constructing a linear motor of a multiphase structure by connecting a plurality of armature units, the length of the armature becomes longer in proportion to the number of the phases, thus limiting the locations where the apparatus can be installed. The problem is solved by a linear drive apparatus comprising a plurality of armature units 3 formed by a magnetic material on which a conductor coil 4 is disposed, and an armature comprising an arrangement of the armature units 3. The armature units 3 comprise a plurality of opposing portions having opposing magnetic pole teeth. The magnetic pole teeth of adjacent opposing portions are arranged in an interdigitated manner. A secondary member 6 is disposed between magnetic pole teeth of the opposing portions. The armature units 3 comprise the coil 4 arranged on opposite sides thereof in an alternating manner.Type: ApplicationFiled: December 12, 2005Publication date: May 4, 2006Inventors: Houng Kim, Kohji Maki, Misao Tadokoro, Hideki Shimane, Hitoshi Shibata, Keijiro Sakai
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Patent number: 7004694Abstract: The conventional linear drive apparatus has the problem that in constructing a linear motor of a multiphase structure by connecting a plurality of armature units, the length of the armature becomes longer in proportion to the number of the phases, thus limiting the locations where the apparatus can be installed. The problem is solved by a linear drive apparatus comprising a plurality of armature units 3 formed by a magnetic material on which a conductor coil 4 is disposed, and an armature comprising an arrangement of the armature units 3. The armature units 3 comprise a plurality of opposing portions having opposing magnetic pole teeth. The magnetic pole teeth of adjacent opposing portions are arranged in an interdigitated manner. A secondary member 6 is disposed between magnetic pole teeth of the opposing portions. The armature units 3 comprise the coil 4 arranged on opposite sides thereof in an alternating manner.Type: GrantFiled: August 13, 2003Date of Patent: February 28, 2006Assignee: Hitachi, Ltd.Inventors: Houng Joong Kim, Kohji Maki, Hisao Tadokoro, Hideki Shimane, Hitoshi Shibata, Keijiro Sakai
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Publication number: 20050285597Abstract: At least one superconducting shim coil is wound around a cylinder member disposed approximately coaxially with a group of superconducting main coils, and the positions in the winding center locus in an axial direction change approximately in accordance with a function where a sine or cosine function with a cycle of (360/m) degrees (m; an integer of one or more) in a circumferential direction is mixed with a sine or cosine function with a cycle of (360/(m+2)) degrees.Type: ApplicationFiled: June 27, 2005Publication date: December 29, 2005Inventors: Kohji Maki, Tsuyoshi Wakuda
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Patent number: 6975048Abstract: A drive apparatus overcomes the problems of ensuring accurate mounting of a plurality of armature coils relative to a plurality of magnetic pole position detectors, limitations concerning the location for mounting, and the extension of primary-side length. The drive apparatus comprises a primary side including an arrangement of a plurality of armatures each having a core made of a magnetic material with coil windings. It also comprises a secondary side including a permanent magnet movably supported relative to the armatures via a gap. A magnetic pole position detector is disposed between adjacent armatures.Type: GrantFiled: July 28, 2003Date of Patent: December 13, 2005Assignee: Hitachi, Ltd.Inventors: Houng Joong Kim, Kohji Maki, Hisao Tadokoro, Hideki Shimane, Hitoshi Shibata, Keijirou Sakai
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Publication number: 20050264107Abstract: To reduce the magnetic flux leakage through the gap between magnetic pole teeth of an armature so as to reduce the magnetic attraction force generated between the armature and a needle, an armature unit is provided with two magnetic poles, on the top of which are magnetic pole teeth protruding toward the opposing magnetic pole, where the magnetic pole teeth of the magnetic pole are arranged at two heights, upper and lower, and the magnetic pole teeth of the opposing magnetic pole are arranged at two heights, upper and lower, so that the magnetic flux flows upward and downward alternately between the upper and lower magnetic pole teeth. The needle equipped with permanent magnets moves relatively in the gap between the upper and lower magnetic pole surfaces of the armature unit.Type: ApplicationFiled: May 9, 2005Publication date: December 1, 2005Inventors: Kim Joong, Hiroshi Katayama, Kohji Maki
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Publication number: 20050200209Abstract: In order to reduce load supported by a support mechanism for supporting a movable part so as to prevent the movable part from moving in a horizontal direction when stress is generated thereon in the horizontal direction, there is provided a drive unit including a primary side having a magnetic body around which a coil is wound, and a secondary side having a plurality of permanent magnets, the primary side including magnetic poles and step portions provided on the magnetic poles. The width of each step portion is smaller than the width of each permanent magnet.Type: ApplicationFiled: May 10, 2005Publication date: September 15, 2005Inventors: Houng Kim, Kohji Maki, Yasuo Morooka, Isamu Numata, Hisao Tadokoro, Takeo Morimoto, Yasunori Sannohe, Hiroshi Ueno, Hideki Shimane
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Patent number: 6943465Abstract: To reduce the magnetic flux leakage through the gap between magnetic pole teeth of an armature so as to reduce the magnetic attraction force generated between the armature and a needle, an armature unit is provided with two magnetic poles 1 and 2, on the top of which are magnetic pole teeth 11a, 12b, 21b, and 22a protruding toward the opposing magnetic pole, where the magnetic pole teeth of the magnetic pole 1 are arranged at two heights, upper and lower, and the magnetic pole teeth of the opposing magnetic pole 2 are arranged at two heights, upper and lower, so that the magnetic flux flows upward and downward alternately between the upper and lower magnetic pole teeth. The needle 6 equipped with permanent magnets moves relatively in the gap 8 between the upper and lower magnetic pole surfaces of the armature unit.Type: GrantFiled: March 29, 2004Date of Patent: September 13, 2005Assignee: Hitachi, Ltd.Inventors: Houng Joong Kim, Hiroshi Katayama, Kohji Maki
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Publication number: 20050173181Abstract: An angle-torque sensor has: a torque detection coil that detects a change in state quantity in a mechanism to detect a relative angle made between input axis and output axis of a torsion bar to be twisted by a torque; an angle detection coil that detects a change in state quantity in a mechanism to detect a rotation angle of a reduction axis which rotates with a rotation being transmitted from the input axis or output axis and being reduced by a reduction mechanism; a torque detection circuit that detects the relative angle from the output of the torque detection coil; and an angle detection circuit that detects the rotation angle from the output of the angle detection coil.Type: ApplicationFiled: April 7, 2005Publication date: August 11, 2005Inventors: Ryoso Masaki, Satoru Kaneko, Kohji Maki, Ryoichi Menju
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Patent number: 6926115Abstract: An angle-torque sensor has: a torque detection coil that detects a change in state quantity in a mechanism to detect a relative angle made between input axis and output axis of a torsion bar to be twisted by a torque; an angle detection coil that detects a change in state quantity in a mechanism to detect a rotation angle of a reduction axis which rotates with a rotation being transmitted from the input axis or output axis and being reduced by a reduction mechanism; a torque detection circuit that detects the relative angle from the output of the torque detection coil; and an angle detection circuit that detects the rotation angle from the output of the angle detection coil.Type: GrantFiled: July 31, 2003Date of Patent: August 9, 2005Assignee: Hitachi Cable, Ltd.Inventors: Ryoso Masaki, Satoru Kaneko, Kohji Maki, Ryoichi Menju
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Publication number: 20050134414Abstract: The present invention provides a superconductivity magnet apparatus for generating a uniform magnetic field suitable for NMR applications. The superconductivity magnet apparatus has an access port for allowing an access to the center of the magnetic field from an external position separated away from the center in a direction other than the axial direction of a split-type superconductivity electromagnet employed in the magnet apparatus. In the superconductivity magnet apparatus, a gap exists between first and second superconductivity coil blocks facing each other to form the split-type superconductivity electromagnet. To put it in detail, the access port allows an access to a measurement space at the center of the magnet by way of the gap. A configuration element of the magnet such as a coil bobbin is cut out for providing the access port. An area including a deficiency portion caused by the cutout portion or the like is filled up with a material having a relative magnetic permeability in the range 1.Type: ApplicationFiled: February 26, 2004Publication date: June 23, 2005Inventors: Tsuyoshi Wakuda, Kohji Maki, Mitsuyoshi Tsuchiya, Michiya Okada, Hideo Tsukamoto, Souji Kajiura, Shuichi Kido
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Patent number: 6876108Abstract: Disclosed herewith a compact linear motor provided with a plurality of magnetic pole teeth and used to increase the thrust force by canceling a magnetic attractive force working between the primary member and the secondary member. The linear motor comprises a primary member and a secondary member. The primary member includes cores formed with a magnetic material and an electromagnetic coil wound on the cores while the secondary member supported so as to be capable of moving relatively with respect to the primary member with a gap therebetween. In the linear motor, the coil that is wound commonly on the cores is also disposed between adjacent magnetic pole teeth.Type: GrantFiled: August 20, 2003Date of Patent: April 5, 2005Assignee: Hitachi, Ltd.Inventors: Kohji Maki, Houng Joong Kim, Yasuo Morooka, Keijirou Sakai, Hitoshi Shibata, Hideki Shimane, Hisao Tadokoro, Takashi Kobayashi
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Publication number: 20040257082Abstract: To access a measurement space 3 located at the center of the magnet, an access port is provided in the direction of the magnet's axis, a clearance 12 is provided in the coil winding portion, and another access port passes through the clearance so that a sample can be positioned perpendicularly to the coil axis. According to this configuration, an access port passing through the coil winding portion can be smaller than the access port passing through the coil axis, a sample is inserted from the access port, a probe is inserted from the access port passing through the magnet axis, and thus the clearance can be minimized.Type: ApplicationFiled: April 2, 2004Publication date: December 23, 2004Inventors: Tsuyoshi Wakuda, Michiya Okada, Tomomi Kikuta, Kohji Maki, Hiroshi Morita, Shuichi Kido, Tomoo Chiba, Hideo Tsukamoto
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Patent number: 6825581Abstract: To reduce the magnetic flux leakage through the gap between magnetic pole teeth of an armature so as to reduce the magnetic attraction force generated between the armature and a needle, an armature unit is provided with two magnetic poles 1 and 2, on the top of which are magnetic pole teeth 11a, 21b, and 22a protruding toward the opposing magnetic pole, where the magnetic pole teeth of the magnetic pole 1 are arranged at two heights, upper and lower, and the magnetic pole teeth of the opposing magnetic pole 2 are arranged at two heights, upper and lower, so that the magnetic flux flows upward and downward alternately between the upper and lower magnetic pole teeth. The needle 6 equipped with permanent magnetic moves relatively in the gap 8 between the upper and lower magnetic pole surfaces of the armature unit.Type: GrantFiled: November 1, 2001Date of Patent: November 30, 2004Assignee: Hitachi, Ltd.Inventors: Kim Houng Joong, Hiroshi Katayama, Kohji Maki