US2676392A - Method of making filamentary electromagnetic transducers - Google Patents
Method of making filamentary electromagnetic transducers Download PDFInfo
- Publication number
- US2676392A US2676392A US324389A US32438952A US2676392A US 2676392 A US2676392 A US 2676392A US 324389 A US324389 A US 324389A US 32438952 A US32438952 A US 32438952A US 2676392 A US2676392 A US 2676392A
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- core
- winding
- filament
- filamentary
- secondary winding
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/17—Construction or disposition of windings
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/1272—Assembling or shaping of elements
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
- Y10T29/4906—Providing winding
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
- Y10T29/4906—Providing winding
- Y10T29/49064—Providing winding by coating
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49073—Electromagnet, transformer or inductor by assembling coil and core
Definitions
- FIG. 2 UCERS p i 1954 F. G. BUHRENDORF METHOD OF MAKING FILAMENTARY ELECTROMAGNETIC TRANSD 2 Sheets-Sheet 1 Original Filed Dec. 22, 1951 FIG. 2
- This invention relates to magnetic heads for use in recording and reproduction, and more particularly to the method of making filamentary type magnetic heads of the kind shown and described in my copending application Serial No. 5 ance with the present invention; I 262,950, filed December 22, 1951, of which the Fig. 6 is a plan view of an embodiment of the present application is a division. present invention in which the transformer core
- the object of this invention is to provide a high is a bar element; frequency magnetic recording and reproducing Fig. '7 is a sectional view taken on the line 7'! head which is economical tomanufacture and of Fig.6 which is efiicient in operation, particularly in the 'Fig. 81s a plan view of an embodiment of the recording and reproduction of microsecond elecpresent invention in which the transformer core trical pulses. is rectangular;
- Fig. 9 is a sectional view taken on the line 9--9 noted requirements are satisfactorily met by a of novel magnetic head which comprises a trans- Fig. 10 is a plan view of an embodiment of the former core carrying two windings.
- the primary present invention inwhich the transformer core winding, which is to be-connected to the assooiis triangular; and ated equipment, consists of a convenient number
- Fig. 11 is a sectional View taken on the line of turns of insulatednwire, such as enamel cov- I-l-H of Fig. 10; ered copper.
- the secondary e a v m e of a h permeability, ow os winding is closed. and consists .of one or several magnetic material such as ferrite.
- the endless turns terminated in a slender.
- filament of cone secondary winding 4 consists of one turn as shown ducting material disposed in a groove in the in Figs. 1, 2, '6,- 8 and 10 or a plurality of turns as outer peripheral face of the core. Flux surround: shown in Figs.
- the primary winding 8 An important feature of this invention resides. c mpr e a plurality f u ns of i su ated 10w in the structure of the secondary winding and resistance W u as'enamel Covered op the method of disposing said Winding directly on Wire, Wound in such manner as to be coupled the surface of the core when said core is made of cl y to th Core the Secondary Winding a reasonably non-conductive material such as The'number of turns in this winding is defined ferrite.
- Fig 1 is a plan View of an embodiment of the in which the filament lies at an angle with respect present invention in which th tran orm core ggr fi n igr lig ifii rrf ii zf ci se zfid z n gl i g :1 1tgrmdal and the secondary winding is a single mounting the filament sh 0111 d be located parallel to the axis of the core as shown in each of the Fig.
- the filament should lie in l 3 1S plan VleW of emb d nt 9 th a plane parallel to the surface "of therecord pre e inventionin which n me co e medium and normal to the direction of the rela- 5 toroidal an the y-winding cow/ 1. 9f tive motion of the recording hea d with respect in to the record medium;
- Fig. i is a view'in perspective of the secondary winding shown in Fig. 3
- Fig. 5 is a view in'perspective showing the actual dimensions of a magnetic head in accordeese
- the particular embodiments of this invention as shown in Figs. 1 to 11 are intended for use with a right circular cylindrical record medium revolving about its axis.
- the recording head is placed so that the filament clears the surface of the cylinder by 0.002 inch and the axis of the core of each of the embodiments, except the one shown in Figs. 6 and 7, is parallel to the axis of the cylinder.
- the axis of the core of the embodiment shown in Figs. 6 and '7 is normal to the axis of the cylinder.
- the secondary winding may be applied directly to the surface of the core 2. It has been found that the following procedure will provide a satisfactory secondary winding.
- a fine groove i4 substantially 0.003 inch deep and 0.002 inch wide and substantially parallel to the axis of the head is cut in the edge of the core.
- the entire core is then coated, by means of a process such as the Brashears silvering process, with a thin coating of metallic silver and given an electrodeposited copper flash.
- the entire core will have, at this point of the process, a cop-per coating approximately 0.0001 inch thick.
- the core is then masked with a stop-off lacquer, such as nitrocellulose lacquer, to form an electrical path around the core such as the single turn path shown in Fig.
- a copper or silver plating 0.003 inch thick is then applied to the core.
- the lacquer is removed with a suitable solvent, such as acetone, and the entire core is etched until the surfaces previously masked are free of applied metal.
- the final operation is to lap off the surplus metal on either side of the groove Hi, which is completely filled with copper, or silver, so that only a slender filament 3 will remain to complete the winding at that point.
- the filament 5 should be flush with the surface of the outer edge of the core. It should not be underflush and should not extend beyond the outer edge of the core.
- the width of the filament should be as narrow as practicable. Widening oi the filament widens the recorded spot or area on the record medium and also reduces the efficiency of the recording head.
- the present invention eliminates the high concentration of flux which occurs at the pole tips in magnetic heads having conventional air-gaps and, therefore, permits the use of ferrite or other similar materials which, although saturating easily, have other characteristics which are most desirable for the recording and reproduction of high frequencies.
- ferrite has extremely high resistivity and as a result the eddy currents in the present invention are very low. This important feature is desirable for efficient operation in the recording and reproduction of microsecond electrical pulses.
- the embodiment of the present invention in which the secondary winding is a single turn will provide satisfactory results, particularly at the higher frequencies.
- the embodiment of the present invention in which the secondary winding consists of a plurality of turns and the primary is wound directly over the secondary may be used to greater advantage in those applications where closer cou-- pling between the primary and secondary windings may be desirable.
- the conductor of the secondary winding of each of the embodiments of the present invention should have as large a cross-sectionaspossible
- the area of said cross-section being limited only by the distributed capacity in a turn of the winding. It has been found that the optimum average width of the conductor of the secondary winding is equal to substantially one-tenth the average length of the magnetic path in the core.
- an electromagnetic transducer including a magnetic core and a conductive winding disposed directly thereon, said winding having a substantially uniform predetermined thickness and including a segment of predetermined filamentary width, which comprises disposing in the outer peripheral face of said core a groove having a depth equal to said predetermined winding thickness and a width equal to said predetermined segment width, depositing a relatively thin first coating of low resistance metal on the surface of said core, aiiixing a material to the surface of said coated core in such manner as to form an unmasked surface pattern of said conductive winding, plating said core to add a second coating of low resistance metal to the unmasked portion of said coated core which includes said groove, said second coating having a thickness equal to said predetermined winding thickness, removing said masking material, and etching the entire surface said core to remove said first thin coating of low resistance metal from that portion of the core surface which had been masked.
- an electromagnetic transducer including a transformer core and a closed conductive winding disposed directly thereon, said winding having a substantially uniform predetermined thickness and including a segment of predetermined filamentary width, which comprises disposing in the outer peripheral face of said core a groove having a depth equal to said predetermined winding thickness and a width equal to said predetermined segment width, depositing a relatively thin first coating of low resistance metal on the-surface of said core, affixing a masking material to the surface of said coated core in such manner as to form an unmasked surface pattern of said conductive winding, plating said core to add a second coating of low resistance metal to the unmasked portion of said coated core which includes said groove, said second coating having a thickness equal to said predetermined winding thickness, removing said masking material, etching the entire surface of said core to remove said first thin coating of low resistance metal from that portion of the core surface which hadbeen masked, removing surplus metal from either side of said groove to define said predetermined filamentary width, and disposing an
Description
UCERS p i 1954 F. G. BUHRENDORF METHOD OF MAKING FILAMENTARY ELECTROMAGNETIC TRANSD 2 Sheets-Sheet 1 Original Filed Dec. 22, 1951 FIG. 2
//v l/EN TOP E 6. BUHPENDORF By W ATTORNEY April 27, 1954 F. G. BUHRENDORF 2,676,392
METHOD OF MAKING FILAMENTARY ELECTROMAGNETIC TRANSDUCERS Original Filed Dec. 22, 1951 2 Sheets-Sheet 2 FIG. 6 FIG. 7 /0 MIME/V701? E G. BUHRE/VDORF A T TOPNEV Patented Apr. 27, 1954 METHOD OE MAKING FILAMENTARY ELEQTRQMAGNETIC TRANSDUCERS Frederick G. Buhrendorf, Westfield, N. J.,' assignor' to Bell Telephone LaboratorieSi Incorporated, New York, N Y., a corporation of New York O ina a t n D e r 22, 1, S r
No. 252.959- Divided and'this application De tember t l9 2,.S ia 24.389
zfllaims.
This invention relates to magnetic heads for use in recording and reproduction, and more particularly to the method of making filamentary type magnetic heads of the kind shown and described in my copending application Serial No. 5 ance with the present invention; I 262,950, filed December 22, 1951, of which the Fig. 6 is a plan view of an embodiment of the present application is a division. present invention in which the transformer core The object of this invention is to provide a high is a bar element; frequency magnetic recording and reproducing Fig. '7 is a sectional view taken on the line 7'! head which is economical tomanufacture and of Fig.6 which is efiicient in operation, particularly in the 'Fig. 81s a plan view of an embodiment of the recording and reproduction of microsecond elecpresent invention in which the transformer core trical pulses. is rectangular;
In accordance with this inventionv the above- Fig. 9 isa sectional view taken on the line 9--9 noted requirements are satisfactorily met by a of novel magnetic head which comprises a trans- Fig. 10 is a plan view of an embodiment of the former core carrying two windings. The primary present invention inwhich the transformer core winding, which is to be-connected to the assooiis triangular; and ated equipment, consists of a convenient number Fig. 11 is a sectional View taken on the line of turns of insulatednwire, such as enamel cov- I-l-H of Fig. 10; ered copper. wire, the number of turnsbeing de- Referring now to the accompanying drawings fined by the associated equipment and the struc- 2 is the core of the'magnetic head and is preftural limitations of the core. The secondary e a v m e of a h permeability, ow os winding is closed. and consists .of one or several magnetic material such as ferrite. The endless turns terminated in a slender. filament of cone secondary winding 4 consists of one turn as shown ducting material disposed in a groove in the in Figs. 1, 2, '6,- 8 and 10 or a plurality of turns as outer peripheral face of the core. Flux surround: shown in Figs. 3 and 4 of a low resistance material ing this filament, when current is induced in it, such as copper or silver, and is terminated in a is usedto record on the magnetic medium in slender filament of low resistance, conducting much the same manner as in conventional air, material 6 which is flush with the surface of the gap type heads. In reproduction, current induced O t r edge 0 i ofthe Core: It 16150 be n in this filament generates a flux .in-the core and, stood that an endless secondary winding conby virtue of the transformeraction, a voltage is sisting of a plurality of turns may also be emdelivered to the associated equipment by the ployed with each of the transformer cores shown larger primary winding. in Figs. 6, 8 and 10. The primary winding 8 An important feature of this invention resides. c mpr e a plurality f u ns of i su ated 10w in the structure of the secondary winding and resistance W u as'enamel Covered op the method of disposing said Winding directly on Wire, Wound in such manner as to be coupled the surface of the core when said core is made of cl y to th Core the Secondary Winding a reasonably non-conductive material such as The'number of turns in this winding is defined ferrite. 40 by the associated equipment to which it is to be The nature of the invention and its distinguishc n e d b means of t terminal Wires and ing features and advantages will be more clearly l2, and 7 5 ctl limitations of h C understood from thefollowing detailed descriph f y 35 may be Obtained with tion and the accompanying drawings in which: P m accgrdance l the Present invention Fig 1 is a plan View of an embodiment of the in which the filament lies at an angle with respect present invention in which th tran orm core ggr fi n igr lig ifii rrf ii zf ci se zfid z n gl i g :1 1tgrmdal and the secondary winding is a single mounting the filament sh 0111 d be located parallel to the axis of the core as shown in each of the Fig. 2 1s a View in perspectiveof the secondary embodiments of the present invention wmfimg m E For optimum results the filament should lie in l 3 1S plan VleW of emb d nt 9 th a plane parallel to the surface "of therecord pre e inventionin which n me co e medium and normal to the direction of the rela- 5 toroidal an the y-winding cow/ 1. 9f tive motion of the recording hea d with respect in to the record medium;
a plurality of turns;
2 Fig. i is a view'in perspective of the secondary winding shown in Fig. 3
Fig. 5 is a view in'perspective showing the actual dimensions of a magnetic head in accordeese The particular embodiments of this invention as shown in Figs. 1 to 11 are intended for use with a right circular cylindrical record medium revolving about its axis. The recording head is placed so that the filament clears the surface of the cylinder by 0.002 inch and the axis of the core of each of the embodiments, except the one shown in Figs. 6 and 7, is parallel to the axis of the cylinder. The axis of the core of the embodiment shown in Figs. 6 and '7 is normal to the axis of the cylinder.
In the preparation of the magnetic head, the secondary winding may be applied directly to the surface of the core 2. It has been found that the following procedure will provide a satisfactory secondary winding. A fine groove i4 substantially 0.003 inch deep and 0.002 inch wide and substantially parallel to the axis of the head is cut in the edge of the core. The entire core is then coated, by means of a process such as the Brashears silvering process, with a thin coating of metallic silver and given an electrodeposited copper flash. The entire core will have, at this point of the process, a cop-per coating approximately 0.0001 inch thick. The core is then masked with a stop-off lacquer, such as nitrocellulose lacquer, to form an electrical path around the core such as the single turn path shown in Fig. 2 or the path consisting of a plurality of turns shown in Fig. 4. A copper or silver plating 0.003 inch thick is then applied to the core. After the plating operation the lacquer is removed with a suitable solvent, such as acetone, and the entire core is etched until the surfaces previously masked are free of applied metal. The final operation is to lap off the surplus metal on either side of the groove Hi, which is completely filled with copper, or silver, so that only a slender filament 3 will remain to complete the winding at that point.
The filament 5 should be flush with the surface of the outer edge of the core. It should not be underflush and should not extend beyond the outer edge of the core. The width of the filament should be as narrow as practicable. Widening oi the filament widens the recorded spot or area on the record medium and also reduces the efficiency of the recording head.
The present invention eliminates the high concentration of flux which occurs at the pole tips in magnetic heads having conventional air-gaps and, therefore, permits the use of ferrite or other similar materials which, although saturating easily, have other characteristics which are most desirable for the recording and reproduction of high frequencies. For example, ferrite has extremely high resistivity and as a result the eddy currents in the present invention are very low. This important feature is desirable for efficient operation in the recording and reproduction of microsecond electrical pulses.
It has been found that the embodiment of the present invention in which the secondary winding is a single turn, as shown in Figs. 1, 2, 6, 8 and 10, will provide satisfactory results, particularly at the higher frequencies. The embodiment of the present invention in which the secondary winding consists of a plurality of turns and the primary is wound directly over the secondary, as shown in Figs. 3 and 4, may be used to greater advantage in those applications where closer cou-- pling between the primary and secondary windings may be desirable.
The conductor of the secondary winding of each of the embodiments of the present invention should have as large a cross-sectionaspossible,
the area of said cross-section being limited only by the distributed capacity in a turn of the winding. It has been found that the optimum average width of the conductor of the secondary winding is equal to substantially one-tenth the average length of the magnetic path in the core.
It is to be understood that the above-described arrangements are illustrative of the application of the principles of the invention. Other arrangements may be devised by those skilled in the art without departing from the spirit and scope of the invention.
What is claimed is:
i. The method of making an electromagnetic transducer including a magnetic core and a conductive winding disposed directly thereon, said winding having a substantially uniform predetermined thickness and including a segment of predetermined filamentary width, which comprises disposing in the outer peripheral face of said core a groove having a depth equal to said predetermined winding thickness and a width equal to said predetermined segment width, depositing a relatively thin first coating of low resistance metal on the surface of said core, aiiixing a material to the surface of said coated core in such manner as to form an unmasked surface pattern of said conductive winding, plating said core to add a second coating of low resistance metal to the unmasked portion of said coated core which includes said groove, said second coating having a thickness equal to said predetermined winding thickness, removing said masking material, and etching the entire surface said core to remove said first thin coating of low resistance metal from that portion of the core surface which had been masked.
2. The method of making an electromagnetic transducer including a transformer core and a closed conductive winding disposed directly thereon, said winding having a substantially uniform predetermined thickness and including a segment of predetermined filamentary width, which comprises disposing in the outer peripheral face of said core a groove having a depth equal to said predetermined winding thickness and a width equal to said predetermined segment width, depositing a relatively thin first coating of low resistance metal on the-surface of said core, affixing a masking material to the surface of said coated core in such manner as to form an unmasked surface pattern of said conductive winding, plating said core to add a second coating of low resistance metal to the unmasked portion of said coated core which includes said groove, said second coating having a thickness equal to said predetermined winding thickness, removing said masking material, etching the entire surface of said core to remove said first thin coating of low resistance metal from that portion of the core surface which hadbeen masked, removing surplus metal from either side of said groove to define said predetermined filamentary width, and disposing an open winding on said core.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,647,474 Seymour Nov. 1, 192'? 1,767,715 Stoekle June 24, 1930 2, 6 11 Arlt -1 Jan. 5, 193? 2,230,913 Schuller Feb. 4, 1941 2,538,405 Zenner Jan. 1 1951 2,616,994 Luhn Nov. 4, 1952
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Application Number | Priority Date | Filing Date | Title |
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US324389A US2676392A (en) | 1951-12-22 | 1952-12-05 | Method of making filamentary electromagnetic transducers |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US262950A US2677019A (en) | 1951-12-22 | 1951-12-22 | Magnetic head and method of making same |
US324389A US2676392A (en) | 1951-12-22 | 1952-12-05 | Method of making filamentary electromagnetic transducers |
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US2676392A true US2676392A (en) | 1954-04-27 |
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US324389A Expired - Lifetime US2676392A (en) | 1951-12-22 | 1952-12-05 | Method of making filamentary electromagnetic transducers |
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Cited By (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2756280A (en) * | 1953-04-21 | 1956-07-24 | Rca Corp | Multiple magnetic head construction |
US2879340A (en) * | 1953-03-11 | 1959-03-24 | Burroughs Corp | Magnetic transducing means |
US2896025A (en) * | 1955-06-21 | 1959-07-21 | Francis D Wetherill | Electrostatic loudspeaker |
US2907007A (en) * | 1954-03-29 | 1959-09-29 | British Telecomm Res Ltd | Magnetic recording equipment |
US2919312A (en) * | 1953-03-20 | 1959-12-29 | Siemens Ag | Magnetic heads |
US2921143A (en) * | 1955-05-31 | 1960-01-12 | Ampex | Multiple channel head assembly |
US2963777A (en) * | 1953-03-11 | 1960-12-13 | Burroughs Corp | Methods of making magnetic transducing means |
US3016427A (en) * | 1956-08-24 | 1962-01-09 | North American Aviation Inc | Saturable magnetic head |
US3017614A (en) * | 1954-09-13 | 1962-01-16 | Rca Corp | Magnetic storage device |
US3024318A (en) * | 1955-10-04 | 1962-03-06 | Philips Corp | Glass gap spacer for magnetic heads |
US3042999A (en) * | 1958-10-29 | 1962-07-10 | Ibm | Method of fabricating magnetic printer write heads |
US3055987A (en) * | 1959-11-25 | 1962-09-25 | Litton Ind Of California | Transducer assembly |
US3057967A (en) * | 1958-05-21 | 1962-10-09 | Ibm | Magnetic transducer |
US3068554A (en) * | 1956-12-21 | 1962-12-18 | Ibm | Magnetic core memory making process |
US3080642A (en) * | 1956-02-06 | 1963-03-12 | John P Woods | Method of manufacturing magnetic recording heads |
US3094772A (en) * | 1956-07-26 | 1963-06-25 | Philips Corp | Method of producing magnetic heads with accurately predetermined gap heights |
US3106617A (en) * | 1958-12-24 | 1963-10-08 | Rca Corp | Magnetic recording and reproducing head |
US3130134A (en) * | 1957-01-09 | 1964-04-21 | Ibm | Plated circuit magnetic core array |
US3145452A (en) * | 1958-03-24 | 1964-08-25 | Iit Res Inst | Method of making a magnetic head |
US3163720A (en) * | 1959-02-05 | 1964-12-29 | Webcor Inc | Magnetic head |
US3175049A (en) * | 1960-07-15 | 1965-03-23 | Minnesota Mining & Mfg | Magnetic scanning head |
US3177297A (en) * | 1959-06-16 | 1965-04-06 | Sony Corp | Boundary displacement multi-channel magnetic head |
US3183579A (en) * | 1960-05-31 | 1965-05-18 | Rca Corp | Magnetic memory |
US3188400A (en) * | 1961-01-09 | 1965-06-08 | Ampex | Ferrite coating |
US3223983A (en) * | 1958-09-25 | 1965-12-14 | Burroughs Corp | Retentive data store and material |
US3233046A (en) * | 1960-11-04 | 1966-02-01 | William D Moehring | Magnetic head assembly |
US3239914A (en) * | 1959-11-13 | 1966-03-15 | Sony Corp | Method of making magnetic heads |
US3243519A (en) * | 1961-04-06 | 1966-03-29 | Burroughs Corp | Electromagnetic transducer with twisted wire core |
US3246384A (en) * | 1961-04-25 | 1966-04-19 | Gen Instrument Corp | Method of making a transducer |
US3249700A (en) * | 1960-09-27 | 1966-05-03 | Philips Corp | Magnetic heads with means for preventing side erosion |
US3258542A (en) * | 1961-04-17 | 1966-06-28 | Ampex | Wedge-shaped magnetic transducer |
US3268987A (en) * | 1959-05-11 | 1966-08-30 | Adams Edmond | Method of making transducer head cores |
US3341667A (en) * | 1962-03-19 | 1967-09-12 | Ibm | Magnetic transducer with single piece core |
US3383759A (en) * | 1966-02-18 | 1968-05-21 | Gen Motors Corp | Method of producing a transducer |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1647474A (en) * | 1923-10-25 | 1927-11-01 | Frederick W Seymour | Variable pathway |
US1767715A (en) * | 1927-02-19 | 1930-06-24 | Central Radio Lab | Electrical resistance |
US2066511A (en) * | 1935-07-20 | 1937-01-05 | Bell Telephone Labor Inc | Wiring device |
US2230913A (en) * | 1936-03-03 | 1941-02-04 | Licentia Gmbh | Magnetic sound recorder |
US2538405A (en) * | 1948-04-27 | 1951-01-16 | Armour Res Found | Electromagnetic transducer head assembly |
US2616994A (en) * | 1948-05-06 | 1952-11-04 | Ibm | Rotary switch |
-
1952
- 1952-12-05 US US324389A patent/US2676392A/en not_active Expired - Lifetime
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1647474A (en) * | 1923-10-25 | 1927-11-01 | Frederick W Seymour | Variable pathway |
US1767715A (en) * | 1927-02-19 | 1930-06-24 | Central Radio Lab | Electrical resistance |
US2066511A (en) * | 1935-07-20 | 1937-01-05 | Bell Telephone Labor Inc | Wiring device |
US2230913A (en) * | 1936-03-03 | 1941-02-04 | Licentia Gmbh | Magnetic sound recorder |
US2538405A (en) * | 1948-04-27 | 1951-01-16 | Armour Res Found | Electromagnetic transducer head assembly |
US2616994A (en) * | 1948-05-06 | 1952-11-04 | Ibm | Rotary switch |
Cited By (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2963777A (en) * | 1953-03-11 | 1960-12-13 | Burroughs Corp | Methods of making magnetic transducing means |
US2879340A (en) * | 1953-03-11 | 1959-03-24 | Burroughs Corp | Magnetic transducing means |
US2919312A (en) * | 1953-03-20 | 1959-12-29 | Siemens Ag | Magnetic heads |
US2756280A (en) * | 1953-04-21 | 1956-07-24 | Rca Corp | Multiple magnetic head construction |
US2907007A (en) * | 1954-03-29 | 1959-09-29 | British Telecomm Res Ltd | Magnetic recording equipment |
US3017614A (en) * | 1954-09-13 | 1962-01-16 | Rca Corp | Magnetic storage device |
US2921143A (en) * | 1955-05-31 | 1960-01-12 | Ampex | Multiple channel head assembly |
US2896025A (en) * | 1955-06-21 | 1959-07-21 | Francis D Wetherill | Electrostatic loudspeaker |
US3024318A (en) * | 1955-10-04 | 1962-03-06 | Philips Corp | Glass gap spacer for magnetic heads |
US3080642A (en) * | 1956-02-06 | 1963-03-12 | John P Woods | Method of manufacturing magnetic recording heads |
US3094772A (en) * | 1956-07-26 | 1963-06-25 | Philips Corp | Method of producing magnetic heads with accurately predetermined gap heights |
US3016427A (en) * | 1956-08-24 | 1962-01-09 | North American Aviation Inc | Saturable magnetic head |
US3068554A (en) * | 1956-12-21 | 1962-12-18 | Ibm | Magnetic core memory making process |
US3130134A (en) * | 1957-01-09 | 1964-04-21 | Ibm | Plated circuit magnetic core array |
US3145452A (en) * | 1958-03-24 | 1964-08-25 | Iit Res Inst | Method of making a magnetic head |
US3057967A (en) * | 1958-05-21 | 1962-10-09 | Ibm | Magnetic transducer |
US3223983A (en) * | 1958-09-25 | 1965-12-14 | Burroughs Corp | Retentive data store and material |
US3042999A (en) * | 1958-10-29 | 1962-07-10 | Ibm | Method of fabricating magnetic printer write heads |
US3106617A (en) * | 1958-12-24 | 1963-10-08 | Rca Corp | Magnetic recording and reproducing head |
US3163720A (en) * | 1959-02-05 | 1964-12-29 | Webcor Inc | Magnetic head |
US3268987A (en) * | 1959-05-11 | 1966-08-30 | Adams Edmond | Method of making transducer head cores |
US3177297A (en) * | 1959-06-16 | 1965-04-06 | Sony Corp | Boundary displacement multi-channel magnetic head |
US3239914A (en) * | 1959-11-13 | 1966-03-15 | Sony Corp | Method of making magnetic heads |
US3055987A (en) * | 1959-11-25 | 1962-09-25 | Litton Ind Of California | Transducer assembly |
US3183579A (en) * | 1960-05-31 | 1965-05-18 | Rca Corp | Magnetic memory |
US3175049A (en) * | 1960-07-15 | 1965-03-23 | Minnesota Mining & Mfg | Magnetic scanning head |
US3249700A (en) * | 1960-09-27 | 1966-05-03 | Philips Corp | Magnetic heads with means for preventing side erosion |
US3233046A (en) * | 1960-11-04 | 1966-02-01 | William D Moehring | Magnetic head assembly |
US3188400A (en) * | 1961-01-09 | 1965-06-08 | Ampex | Ferrite coating |
US3243519A (en) * | 1961-04-06 | 1966-03-29 | Burroughs Corp | Electromagnetic transducer with twisted wire core |
US3258542A (en) * | 1961-04-17 | 1966-06-28 | Ampex | Wedge-shaped magnetic transducer |
US3246384A (en) * | 1961-04-25 | 1966-04-19 | Gen Instrument Corp | Method of making a transducer |
US3341667A (en) * | 1962-03-19 | 1967-09-12 | Ibm | Magnetic transducer with single piece core |
US3383759A (en) * | 1966-02-18 | 1968-05-21 | Gen Motors Corp | Method of producing a transducer |
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