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).
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Patent number: 8512590Abstract: 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: GrantFiled: August 17, 2011Date of Patent: August 20, 2013Assignee: Hitachi Metals, Ltd.Inventors: Takashi Takami, Hiroshi Iwasaki, Yoshinori Kobayashi, Naoki Mochi, Ryuji Gotoh
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Patent number: 8303837Abstract: 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: GrantFiled: February 13, 2007Date of Patent: November 6, 2012Assignee: Hitachi Metals, Ltd.Inventors: Takashi Takami, Hiroshi Iwasaki, Yoshinori Kobayashi, Naoki Mochi, Ryuji Gotoh
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Publication number: 20120211910Abstract: 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: ApplicationFiled: August 17, 2011Publication date: August 23, 2012Applicant: HITACHI METALS, LTD.Inventors: Takashi TAKAMI, Hiroshi IWASAKI, Yoshinori KOBAYASHI, Naoki MOCHI, Ryuji GOTOH
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Patent number: 8021567Abstract: 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: GrantFiled: October 12, 2010Date of Patent: September 20, 2011Assignee: Hitachi Metals, Ltd.Inventors: Takashi Takami, Hiroshi Iwasaki, Naoki Mochi
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Patent number: 7906036Abstract: 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: GrantFiled: September 13, 2004Date of Patent: March 15, 2011Assignee: Neomax Co., Ltd.Inventors: Takashi Takami, Yasunobu Ogata
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Publication number: 20110024672Abstract: 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: ApplicationFiled: October 12, 2010Publication date: February 3, 2011Applicant: HITACHI METALS, LTDInventors: Takashi TAKAMI, Hiroshi IWASAKI, Naoki MOCHI
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Patent number: 7837893Abstract: 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: GrantFiled: March 10, 2006Date of Patent: November 23, 2010Assignee: Hitachi Metals, Ltd.Inventors: Takashi Takami, Hiroshi Iwasaki, Naoki Mochi
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Publication number: 20090218540Abstract: 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: ApplicationFiled: February 13, 2007Publication date: September 3, 2009Applicant: Hitachi Metals, Ltd.Inventors: Takashi Takami, Hiroshi Iwasaki, Yoshinori Kobayashi, Naoki Mochi, Ryuji Gotoh
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Publication number: 20090022992Abstract: 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: ApplicationFiled: March 10, 2006Publication date: January 22, 2009Applicant: HITACHI METALS, LTD.Inventors: Takashi Takami, Hiroshi Iwasaki, Naoki Mochi
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Patent number: 7169319Abstract: 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: GrantFiled: October 14, 2004Date of Patent: January 30, 2007Assignee: Neomax Co., Ltd.Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
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Publication number: 20060284136Abstract: 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: ApplicationFiled: September 14, 2004Publication date: December 21, 2006Inventors: Takashi Takami, Yasunobu Ogata
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Publication number: 20050098761Abstract: 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: ApplicationFiled: October 14, 2004Publication date: May 12, 2005Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
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Patent number: 6858156Abstract: 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: GrantFiled: January 16, 2003Date of Patent: February 22, 2005Assignee: Hitachi Metals, Ltd.Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
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Patent number: 6737011Abstract: 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: GrantFiled: November 9, 1999Date of Patent: May 18, 2004Assignee: Hitachi Metals, Ltd.Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
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Publication number: 20030168785Abstract: 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: ApplicationFiled: January 16, 2003Publication date: September 11, 2003Applicant: HITACHI METALS, LTD.Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
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Patent number: 6383407Abstract: 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: GrantFiled: February 16, 2001Date of Patent: May 7, 2002Assignee: Hitachi Metals, Ltd.Inventors: Yasunobu Ogata, Yutaka Kubota, Takashi Takami, Shuichi Shiina
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Publication number: 20010023933Abstract: 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: ApplicationFiled: February 16, 2001Publication date: September 27, 2001Inventors: Yasunobu Ogata, Yutaka Kubota, Takashi Takami, Shuichi Shiina
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Patent number: 6284150Abstract: 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: GrantFiled: September 23, 1999Date of Patent: September 4, 2001Assignee: Hitachi Metals, Ltd.Inventors: Yasunobu Ogata, Yutaka Kubota, Takashi Takami, Shuichi Shiina
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Patent number: 5958284Abstract: 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: GrantFiled: December 29, 1997Date of Patent: September 28, 1999Assignee: Hitachi Metals, Ltd.Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata