Patents by Inventor Takashi Takami

Takashi Takami 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: 8512590
    Abstract: A method for producing a sintered ferrite magnet having an M-type ferrite structure and represented by: Ca1?x?yRxBayFe2n-zCoz, (by atomic ratio), where 0.3?1?x?y?0.65, 0.2?x?0.65, 0.001?y?0.2, 0.03?z?0.65, 4?n?7, and 1?x?y>y. The method includes mixing a Ca compound, an R element compound, a Ba compound, an iron compound and a Co compound as starting materials; calcining the starting materials to obtain calcined bodies; pulverizing the calcined bodies to obtain a calcined powder; providing recycled materials having an M-type ferrite structure and being represented by the above formula; pulverizing the recycled materials to obtain a recycled material powder; mixing the recycled material powder with the calcined powder to form a moldable material; molding the moldable material to obtain green bodies; and sintering the green bodies to obtain the sintered ferrite magnet.
    Type: Grant
    Filed: August 17, 2011
    Date of Patent: August 20, 2013
    Assignee: Hitachi Metals, Ltd.
    Inventors: Takashi Takami, Hiroshi Iwasaki, Yoshinori Kobayashi, Naoki Mochi, Ryuji Gotoh
  • Patent number: 8303837
    Abstract: A rotating machine comprising a sintered ferrite magnet having an M-type ferrite structure, comprising Ca, an R element that is at least one of rare earth elements and indispensably includes La, Ba, Fe and Co as indispensable elements, and having a composition represented by the formula: Ca1-x-yRxBayFe2n-zCoz, wherein (1?x?y), x, y, z and n represent the contents of Ca, the R element, Ba and Co, and a molar ratio, meeting 0.3?1?x?y?0.65, 0.2?x?0.65, 0.001?y?0.2, 0.03?z?0.65, 4?n?7, and 1?x?y>y; a bonded magnet comprising ferrite powder having the above composition and a binder, and a magnet roll, at least one magnetic pole portion of which is made of the above bonded magnet.
    Type: Grant
    Filed: February 13, 2007
    Date of Patent: November 6, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Takashi Takami, Hiroshi Iwasaki, Yoshinori Kobayashi, Naoki Mochi, Ryuji Gotoh
  • Publication number: 20120211910
    Abstract: A rotating machine comprising a sintered ferrite magnet having an M-type ferrite structure, comprising Ca, an R element that is at least one of rare earth elements and indispensably includes La, Ba, Fe and Co as indispensable elements, and having a composition represented by the formula: Ca1?x?yRxBayFe2n?zCoz, wherein (1?x?y), x, y, z and n represent the contents of Ca, the R element, Ba and Co, and a molar ratio, meeting 0.3?1?x?y?0.65, 0.2?x?0.65, 0.001?y?0.2, 0.03?z?0.65, 4?n?7, and 1?x?y>y; a bonded magnet comprising ferrite powder having the above composition and a binder, and a magnet roll, at least one magnetic pole portion of which is made of the above bonded magnet.
    Type: Application
    Filed: August 17, 2011
    Publication date: August 23, 2012
    Applicant: HITACHI METALS, LTD.
    Inventors: Takashi TAKAMI, Hiroshi IWASAKI, Yoshinori KOBAYASHI, Naoki MOCHI, Ryuji GOTOH
  • Patent number: 8021567
    Abstract: A sintered ferrite magnet having an M-type ferrite structure and comprising Ca, an R element which is at least one rare earth element indispensably including La, Ba, Fe and Co as indispensable elements, which is represented by Ca1-x-yRxBayFe2n-zCoz, wherein (1?x?y), x, y, z and n are numbers representing the amounts of Ca, the R element, Ba and Co and a molar ratio, meeting 0.2?x?0.65, 0.001?y?0.2, 0.03?z?0.65, and 4?n?7.
    Type: Grant
    Filed: October 12, 2010
    Date of Patent: September 20, 2011
    Assignee: Hitachi Metals, Ltd.
    Inventors: Takashi Takami, Hiroshi Iwasaki, Naoki Mochi
  • Patent number: 7906036
    Abstract: A sintered ferrite magnet having a basic composition represented by the general formula: A1?x?y+aCax+bRy+cFe2n?zCoz+dO19 (atomic ratio), wherein a, b, c and d represent the amounts of an A element, Ca, an R element and Co added in the pulverization step of an oxide magnet material, which are numerals meeting the conditions of 0.03?x?0.4, 0.1?y?0.6, 0?z?0.4, 4?n?10, x+y<1, 0.03?x+b?0.4, 0.1?y+c?0.6, 0.1?z+d?0.4, 0.50?[(1?x?y+a)/(1?y+a+b)]?0.97, 1.1?(y+c)/(z+d)?1.8, 1.0?(y+c)/x?20, and 0.1?x/(z+d)?1.2.
    Type: Grant
    Filed: September 13, 2004
    Date of Patent: March 15, 2011
    Assignee: Neomax Co., Ltd.
    Inventors: Takashi Takami, Yasunobu Ogata
  • Publication number: 20110024672
    Abstract: A sintered ferrite magnet having an M-type ferrite structure and comprising Ca, an R element which is at least one rare earth element indispensably including La, Ba, Fe and Co as indispensable elements, which is represented by Ca1?x?yRxBayFe2n?zCoz, wherein (1?x?y), x, y, z and n are numbers representing the amounts of Ca, the R element, Ba and Co and a molar ratio, meeting 0.2?x?0.65, 0.001?y?0.2, 0.03?z?0.65, and 4?n?7.
    Type: Application
    Filed: October 12, 2010
    Publication date: February 3, 2011
    Applicant: HITACHI METALS, LTD
    Inventors: Takashi TAKAMI, Hiroshi IWASAKI, Naoki MOCHI
  • Patent number: 7837893
    Abstract: A sintered ferrite magnet having an M-type ferrite structure and comprising Ca, an R element which is at least one rare earth element indispensably including La, Ba, Fe and Co as indispensable elements, which is represented by Ca1-x-yRxBayFe2n-zCoz, wherein (1-x-y), x, y, z and n are numbers representing the amounts of Ca, the R element, Ba and Co and a molar ratio, meeting 0.2?x?0.65, 0.001?y?0.2, 0.03?z?0.65, and 4?n?7.
    Type: Grant
    Filed: March 10, 2006
    Date of Patent: November 23, 2010
    Assignee: Hitachi Metals, Ltd.
    Inventors: Takashi Takami, Hiroshi Iwasaki, Naoki Mochi
  • Publication number: 20090218540
    Abstract: A rotating machine comprising a sintered ferrite magnet having an M-type ferrite structure, comprising Ca, an R element that is at least one of rare earth elements and indispensably includes La, Ba, Fe and Co as indispensable elements, and having a composition represented by the formula: Ca1-x-yRxBayFe2n-zCoz, wherein (1?x?y), x, y, z and n represent the contents of Ca, the R element, Ba and Co, and a molar ratio, meeting 0.3?1?x?y?0.65, 0.2?x?0.65, 0.001?y?0.2, 0.03?z?0.65, 4?n?7, and 1?x?y>y; a bonded magnet comprising ferrite powder having the above composition and a binder, and a magnet roll, at least one magnetic pole portion of which is made of the above bonded magnet.
    Type: Application
    Filed: February 13, 2007
    Publication date: September 3, 2009
    Applicant: Hitachi Metals, Ltd.
    Inventors: Takashi Takami, Hiroshi Iwasaki, Yoshinori Kobayashi, Naoki Mochi, Ryuji Gotoh
  • Publication number: 20090022992
    Abstract: A sintered ferrite magnet having an M-type ferrite structure and comprising Ca, an R element which is at least one rare earth element indispensably including La, Ba, Fe and Co as indispensable elements, which is represented by Ca1-x-yRxBayFe2n-zCoz, wherein (1-x-y), x, y, z and n are numbers representing the amounts of Ca, the R element, Ba and Co and a molar ratio, meeting 0.2?x?0.65, 0.001?y?0.2, 0.03?z?0.65, and 4?n?7.
    Type: Application
    Filed: March 10, 2006
    Publication date: January 22, 2009
    Applicant: HITACHI METALS, LTD.
    Inventors: Takashi Takami, Hiroshi Iwasaki, Naoki Mochi
  • Patent number: 7169319
    Abstract: A ferrite magnet having a basic composition represented by the following general formula: (A1?xRx)O.n[(Fe1?yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R is at least one of rare earth elements including Y, M is at least one element selected from the group consisting of Co, Mn, Ni and Zn, and x, y and n are numbers meeting the conditions of 0.01?x?0.4, [x/(2.6n)]?y?[x/(1.6n)], and 5?n?6, and substantially having a magnetoplumbite-type crystal structure, is obtained by uniformly mixing a compound of Sr and/or Ba with an iron compound; calcining the resultant uniform mixture; adding a compound of the R element and/or the M element to the resultant calcined powder at a pulverization step thereof; and sintering the resultant mixture. The compound of the R element and/or the M element may be added at a percentage of more than 0 atomic % and 80 atomic % or less, on an element basis, at a mixing step before calcination.
    Type: Grant
    Filed: October 14, 2004
    Date of Patent: January 30, 2007
    Assignee: Neomax Co., Ltd.
    Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
  • Publication number: 20060284136
    Abstract: A sintered ferrite magnet having a basic composition represented by the general formula: A1?x?y+aCax+bRy+cFe2n?zCoz+dO19 (atomic ratio), wherein a, b, c and d represent the amounts of an A element, Ca, an R element and Co added in the pulverization step of an oxide magnet material, which are numerals meeting the conditions of 0.03?x?0.4, 0.1?y?0.6, 0?z?0.4, 4?n?10, x+y?1, 0.03?x+b?0.4, 0.1?y+c?0.6, 0.1?z+d?0.4, 0.50?[(1?x?y+a)/(1?y+a+b)]?0.97, 1.1?(y+c)/(z+d)?1.8, 1.0?(y+c)/x?20, and 0.1?x/(z+d)?1.2.
    Type: Application
    Filed: September 14, 2004
    Publication date: December 21, 2006
    Inventors: Takashi Takami, Yasunobu Ogata
  • Publication number: 20050098761
    Abstract: A ferrite magnet having a basic composition represented by the following general formula: (A1-xRx)O.n[(Fe1-yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R is at least one of rare earth elements including Y, M is at least one element selected from the group consisting of Co, Mn, Ni and Zn, and x, y and n are numbers meeting the conditions of 0.01?x?0.4, [x/(2.6n)]?y?[x/(1.6n)], and 5?n?6, and substantially having a magnetoplumbite-type crystal structure, is obtained by uniformly mixing a compound of Sr and/or Ba with an iron compound; calcining the resultant uniform mixture; adding a compound of the R element and/or the M element to the resultant calcined powder at a pulverization step thereof; and sintering the resultant mixture. The compound of the R element and/or the M element may be added at a percentage of more than 0 atomic % and 80 atomic % or less, on an element basis, at a mixing step before calcination.
    Type: Application
    Filed: October 14, 2004
    Publication date: May 12, 2005
    Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
  • Patent number: 6858156
    Abstract: A ferrite magnet having a basic composition represented by the following general formula: (A1?xRx)O.n[(Fe1?yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R is at least one of rare earth elements including Y, M is at least one element selected from the group consisting of Co, Mn, Ni and Zn, and x, y and n are numbers meeting the conditions of 0.01?x?0.4, [x/(2.6n)]?y?[x/(1.6n)], and 5?n?6, and substantially having a magnetoplumbite crystal structure, is obtained by uniformly mixing a compound of Sr and/or Ba with an iron compound; calcining the resultant uniform mixture; adding a compound of the R element and/or the M element to the resultant calcined powder at a pulverization step thereof; and sintering the resultant mixture. The compound of the R element and/or the M element may be added at a percentage of more than 0 atomic % and 80 atomic % or less, on an element basis, at a mixing step before calcination.
    Type: Grant
    Filed: January 16, 2003
    Date of Patent: February 22, 2005
    Assignee: Hitachi Metals, Ltd.
    Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
  • Patent number: 6737011
    Abstract: A ferrite magnet having a basic composition represented by the following general formula: (A1−xRx)O.n[(Fe1−yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R is at least one of rare earth elements including Y, M is at least one element selected from the group consisting of Co, Mn, Ni and Zn, and x, y and n are numbers meeting the conditions of 0.01≦x≦0.4, [x/(2.6n)]≦y≦[x/(1.6n)], and 5≦n≦6, and substantially having a magnetoplumbite crystal structure, is obtained by uniformly mixing a compound of Sr and/or Ba with an iron compound; calcining the resultant uniform mixture; adding a compound of the R element and/or the M element to the resultant calcined powder at a pulverization step thereof; and sintering the resultant mixture. The compound of the R element and/or the M element may be added at a percentage of more than 0 atomic % and 80 atomic % or less, on an element basis, at a mixing step before calcination.
    Type: Grant
    Filed: November 9, 1999
    Date of Patent: May 18, 2004
    Assignee: Hitachi Metals, Ltd.
    Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
  • Publication number: 20030168785
    Abstract: A ferrite magnet having a basic composition represented by the following general formula: (A1-xRx)O.n[(Fe1-yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R is at least one of rare earth elements including Y, M is at least one element selected from the group consisting of Co, Mn, Ni and Zn, and x, y and n are numbers meeting the conditions of 0.01≦x≦0.4, [x/(2.6n)]≦y≦[x/(1.6n)], and 5≦n≦6, and substantially having a magnetoplumbite-type crystal structure, is obtained by uniformly mixing a compound of Sr and/or Ba with an iron compound; calcining the resultant uniform mixture; adding a compound of the R element and/or the M element to the resultant calcined powder at a pulverization step thereof; and sintering the resultant mixture. The compound of the R element and/or the M element may be added at a percentage of more than 0 atomic % and 80 atomic % or less, on an element basis, at a mixing step before calcination.
    Type: Application
    Filed: January 16, 2003
    Publication date: September 11, 2003
    Applicant: HITACHI METALS, LTD.
    Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
  • Patent number: 6383407
    Abstract: A ferrite powder for bonded magnets having a substantially magnetoplumbite-type crystal structure and an average diameter of 0.9-2 &mgr;m, the ferrite powder having a basic composition represented by the following general formula: (A1−xRx)O.n[(Fe1−yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba; R is at least one of rare earth elements including Y, La being indispensable; M is at least one element selected from the group consisting of Co, Mn, Ni and Zn; and x, y and n are numbers meeting the conditions of 0.01≦x≦0.4, [x/(2.6n)]≦y≦[x/(1.6n)], and 5≦n≦6, (Si+Ca) being 0.2 weight % or less, and (Al+Cr) being 0.13 weight % or less, can be produced by mixing iron oxide containing 0.06 weight % or less of (Si+Ca) and 0.
    Type: Grant
    Filed: February 16, 2001
    Date of Patent: May 7, 2002
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yasunobu Ogata, Yutaka Kubota, Takashi Takami, Shuichi Shiina
  • Publication number: 20010023933
    Abstract: A ferrite powder for bonded magnets having a substantially magnetoplumbite-type crystal structure and an average diameter of 0.9-2 &mgr;m, the ferrite powder having a basic composition represented by the following general formula: (A1-xRx)O.n[(Fe1-yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba; R is at least one of rare earth elements including Y, La being indispensable; M is at least one element selected from the group consisting of Co, Mn, Ni and Zn; and x, y and n are numbers meeting the conditions of 0.01≦x≦0.4, [x/(2.6n)]≦y≦[x/(1.6n)], and 5≦n≦6, (Si+Ca) being 0.2 weight % or less, and (Al+Cr) being 0.13 weight % or less, can be produced by mixing iron oxide containing 0.06 weight % or less of (Si+Ca) and 0.
    Type: Application
    Filed: February 16, 2001
    Publication date: September 27, 2001
    Inventors: Yasunobu Ogata, Yutaka Kubota, Takashi Takami, Shuichi Shiina
  • Patent number: 6284150
    Abstract: A ferrite powder for bonded magnets having a substantially magnetoplumbite-type crystal structure and an average diameter of 0.9-2 &mgr;m, the ferrite powder having a basic composition represented by the following general formula: (A1-xRxO.n[Fe1-yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba; R is at least one of rare earth elements including Y, La being indispensable; M is at least one element selected from the group consisting of Co, Mn, Ni and Zn; and x, y and n are numbers meeting the conditions of 0.01≦x≦0.4, [x/(2.6n)]≦y≦[x/(1.6n)], and 5≦n≦6, (Si+Ca) being 0.2 weight % or less, and (Al+Cr) being 0.13 weight % or less, can be produced by mixing iron oxide containing 0.06 weight % or less of (Si+Ca) and 0.
    Type: Grant
    Filed: September 23, 1999
    Date of Patent: September 4, 2001
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yasunobu Ogata, Yutaka Kubota, Takashi Takami, Shuichi Shiina
  • Patent number: 5958284
    Abstract: The ferrite magnet having a composition represented by the general formula: (A.sub.1-x R.sub.x)O.multidot.n?(Fe.sub.1-y M.sub.y).sub.2 O.sub.3 ! (by atomic ratio), wherein A is Sr and/or Ba, R is at least one element selected from the group consisting of La, Nd, Pr, Sm, Eu and Gd, La being indispensable, M is at least one element selected from the group consisting of Mn, Co and Ni, and x, y and n meet 0.05.ltoreq.x.ltoreq.0.5, x/(2.4n).ltoreq.y.ltoreq.x/(1.6n) and 5.4.ltoreq.n.ltoreq.6.0, respectively is produced by preparing a starting material powder having the above composition and an average particle size of 0.4-0.7 .mu.m, and subjecting the starting material powder to molding in a magnetic field and then to sintering.
    Type: Grant
    Filed: December 29, 1997
    Date of Patent: September 28, 1999
    Assignee: Hitachi Metals, Ltd.
    Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata