Patents by Inventor Itsushi Nakamura
Itsushi Nakamura 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: 7094974Abstract: A polymer SP insulator comprising an FRP core 1, a sheath 2 having a plurality of sheds 6 provided on outer periphery of FRP core 1, and metal-end-fittings 3, 4 crimped to upper and lower ends of FRP core 1, in which a flat plate 11 for adjusting the overall length dimension after crimping the metal-end-fitting 4 is assembled in the inner bottom of the metal-end-fitting 4, and the overall length dimension is uniformly adjusted by the thickness of the flat plate 11. Further, a stress concentration portion such as cross groove is provided in the outer bottom of the lower Metal-end-fitting 4, and prevents instability by deformation of flange 8 when crimping the Metal-end-fitting 4. In this configuration, in spite of the structure of crimping metal-end-fittings at upper and lower ends of the FRP core, the overall length tolerance, parallelism and eccentricity can be suppressed.Type: GrantFiled: November 23, 2005Date of Patent: August 22, 2006Assignee: NGK Insulators, Ltd.Inventors: Yasushi Ohkawa, Itsushi Nakamura
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Publication number: 20060131063Abstract: A polymer SP insulator comprising an FRP core 1, a sheath 2 having a plurality of sheds 6 provided on outer periphery of FRP core 1, and metal-end-fittings 3, 4 crimped to upper and lower ends of FRP core 1, in which a flat plate 11 for adjusting the overall length dimension after crimping the metal-end-fitting 4 is assembled in the inner bottom of the metal-end-fitting 4, and the overall length dimension is uniformly adjusted by the thickness of the flat plate 11. Further, a stress concentration portion such as cross groove is provided in the outer bottom of the lower Metal-end-fitting 4, and prevents instability by deformation of flange 8 when crimping the Metal-end-fitting 4. In this configuration, in spite of the structure of crimping metal-end-fittings at upper and lower ends of the FRP core, the overall length tolerance, parallelism and eccentricity can be suppressed.Type: ApplicationFiled: November 23, 2005Publication date: June 22, 2006Applicant: NGK INSULATORS, LTD.Inventors: Yasushi Ohkawa, Itsushi Nakamura
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Patent number: 6472604Abstract: A seal construction of a polymer insulator has a core member, an outer cover member including a sheath portion and sheds, which is arranged on an outer surface of the core member, and a securing metal fitting is arranged on each end of the core member. A tip portion of the sheath portion is arranged between the securing metal-fitting and the core member, and a sealant is arranged between an inner surface of the securing metal fitting and an outer surface of the tip portion of the sheath portion. The seal construction mentioned above includes a small rib projecting radially outward from the sheath portion of the outer cover member. The small rib has a side surface connected to an open end portion of the securing metal fitting via the sealant, and the sealant does not protrude from a portion between the side surface of the small rib and the open end portion of the securing metal fitting.Type: GrantFiled: March 9, 2001Date of Patent: October 29, 2002Assignee: NGK Insulators, Ltd.Inventors: Itsushi Nakamura, Takashi Imakoma
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Publication number: 20010020544Abstract: A seal construction of a polymer insulator has a core member, an outer cover member including a sheath portion and sheds, which is arranged on an outer surface of the core member, and securing metal fittings arranged on both ends of the core member, wherein a tip portion of the sheathe portion is arranged between the securing metal fitting and the core member and a sealant is arranged between an inner surface of the securing metal fitting and an outer surface of the tip portion of the sheath portion. The seal construction mentioned above has constructions: a small rib projected from the sheath portion of the outer cover member is arranged; a side surface of the small rib is connected to the open end portion of the securing metal fitting via the sealant; and the sealant is not protruded from a portion between the side surface of the small rib and the open end portion of the securing metal fitting.Type: ApplicationFiled: March 9, 2001Publication date: September 13, 2001Applicant: NGK Insulators, Ltd.Inventors: Itsushi Nakamura, Takashi Imakoma
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Patent number: 6055717Abstract: A securing method of a polymer insulator including the steps of inserting an FRP core into a depression portion of a metal member having an open end portion, and connecting the metal member to the FRP core by compressing the FRP core and the metal member is disclosed. The improvement includes the steps of: determining a first region defining a part of a compression portion of the metal member, to which a compression pressure is applied, from a side of the open end portion; determining a second region defining the other part of the compression portion in succession with the first region; and controlling a deformation of the first region in such a manner that a deformation amount of the first region is increased gradually toward the second region.Type: GrantFiled: March 23, 1998Date of Patent: May 2, 2000Assignee: NGK Insulators, Ltd.Inventors: Itsushi Nakamura, Yasushi Ohkawa, Tomio Suzuki, Eiji Kitagami
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Patent number: 5814728Abstract: A nondestructive inspection method of inspecting a securing defect of a polymer insulator having an FRP core, an outer cover portion arranged around the FRP core, and at least one metal member secured to at least one end of the FRP core, includes the steps of; measuring an acoustic emission signal generated when the metal member is secured to the FRP core by using compression dies; and determining whether or not the securing defect is generated on the basis of the acoustic emission signal in process. Moreover, the disclosed apparatus performs the nondestructive inspection method mentioned above.Type: GrantFiled: March 27, 1997Date of Patent: September 29, 1998Assignee: NGK Insulators, Ltd.Inventors: Yasushi Okawa, Itsushi Nakamura, Tomio Suzuki, Masahiro Hori
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Patent number: 4658092Abstract: An explosion-preventing suspension insulator includes an insulator body and a metal cap and a metal pin both being bonded to the insulator body by means of cement. A synthetic resin based electrical insulating film having a Young's modulus of elasticity of from 20,000 to 80,000 kgf/cm.sup.2 is provided in a specific thickness on the inner surface of the metal cap and the outer surface of the metal pin at a portion where the metal pin is buried into the cement. The preferred thickness of each electrical insulating film is from 600 to 1,500 .mu.m.Type: GrantFiled: March 17, 1986Date of Patent: April 14, 1987Assignee: NGK Insulators., Ltd.Inventors: Itsushi Nakamura, Shigeo Mori, Hiroshi Nozaki