[go: up one dir, main page]

US2751440A - Magnetic recording-play-back heads - Google Patents

Magnetic recording-play-back heads Download PDF

Info

Publication number
US2751440A
US2751440A US175402A US17540250A US2751440A US 2751440 A US2751440 A US 2751440A US 175402 A US175402 A US 175402A US 17540250 A US17540250 A US 17540250A US 2751440 A US2751440 A US 2751440A
Authority
US
United States
Prior art keywords
play
plates
contact members
heads
cores
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US175402A
Inventor
John E Deturk
John H Macneill
Gibbs Norman Eliot
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Raytheon Co
Original Assignee
Raytheon Manufacturing Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Raytheon Manufacturing Co filed Critical Raytheon Manufacturing Co
Priority to US175402A priority Critical patent/US2751440A/en
Application granted granted Critical
Publication of US2751440A publication Critical patent/US2751440A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • G11B5/29—Structure or manufacture of unitary devices formed of plural heads for more than one track

Definitions

  • This ⁇ invention relates to magnetic .recording and playback heads, and more particularly .to devices of the general character indicated especially adapted for simultaneous .multiple-channel operation.
  • the main object .of .the present ⁇ invention to eliminate the foregoing disadvantages by providing a head which consists of a plurality-of thin, stacked, single-channel umts which are complete in themselves, which -carry .their own terminals, Aand which maintain proper inter-relationship for their entire useful lives.
  • :It is another object of the present invention to provide a multiple 'head in which each single-channel unit is a duplicate of each other unit, whereby the single units are interchangeable within a particular multiple head, and the multiple heads are likewise interchangeable in the apparatus in which they are employed.
  • a magnetizable core provided with pole pieces spaced by a non-magnetic insert to define a working gap has a coil wound thereon.
  • the coil has its ends electrically connected, respectively, to Contact members. Bonded to the side surfaces of the core and contact members are duplicate plastic plates, said plates being provided with recesses receptive of the windings on the core and bosses engaging contact members.
  • the units thus far described are stacked with magnetic shields therebetween and the assembly is held together and maintained in fixed interrelau'onship by locating rods passing through apertures in the shields, side plates and cores.
  • Magnetic heads embodying the features of the present invention have been constructed and found to have the advantages previously referred to, said advantages having been long sought, for example, in digital computing equipment and data filing systems.
  • the chief virtue of the heads of the present invention is their extreme thinness, heads of .070 inch having been constructed whih permit eticient employment of the medium on which the recording is accomplished.
  • Fig. 4l is an'exploded side elevational view showing the components making up each single-channel unit
  • Fig. 2 is aside elevational view of a partially assembled single-channel unit
  • Fig. 3 is a similar view of the same completely assembled.
  • Fig. 4 is an edge view of an assembled multiple head incorporating a plurality of the single-channel units shown in Fig. 3.
  • the numeral 10 generally designates a dat magnetizable core consisting-of amain rectangular portion 1l, a transverse, substantially'rectangular portion 12 at one end of said main portion, and a transverse, substantially triangular portion 13 at the other end of said main portion.
  • the rectangular portions 12 having abutting inner surfaces 14 to complete the magnetic circuit
  • the ⁇ triangular portions 1.3 constituting pole pieces, having flattened portions -ISYadapted to support an insert 16 of nomnagnetic material therebetween to dene a working'gap.
  • v'Each 'of the-'cores 10 has a coil 17 wound on the'main portion 11 thereof, the coils being series-connected by splicing together the lower ends thereof, as at 1S, the upper, free ends thereof being connected, respectively, to contact members 19 and 20.
  • the members 1g and 20 are substantially rectangular in shape, except that their side edges are curved inwardly, as at 21 and 22, lugs 23 depending from the lower edges thereof, and olf-set tongues 24 extending from the upper edges thereof.
  • the plates 25 are also bonded to the side surfaces of the contact members 19 and 29, and, through the bosses 27 and 28, to each other, the curved edges 21 and 22 of said contact members engaging substantially elliptical bosses 28 formed on said plates, whereby said contact members are maintained in appropriate alignment.
  • Fig. 2 of the drawing most clearly shows the cores and contact members in position on one of the side plates, and it is to be noted that said cores and contact members lie in a common plane.
  • the single-channel unit completed by the addition of a second side plate, the completed unit being most clearly shown in Fig. 3 of the drawings.
  • a plurality of the units shown in Fig. 3 are stacked together with magnetic shields 29 between each pair, the assembly being held together and maintained in proper inter-relationship by locating rods 30 passing through openings 31 in the side plates 25, openings 32 in the cores 10, and, of course, aligned openings (no reference characters) in the shields 29.
  • the openings 32 are accurately located with respect to the surfaces 14 and 15, the openings 31 are slightly larger than the openings 32, and the rods 30 t the openings 32 precisely, so that, when the units are stacked as aforesaid, all of the abutting surfaces 14 and the working "ice gaps become accurately aligned with respect to each other and with respect to the rods 30.
  • the assembly is completed by suitable end plates 33 and 34.
  • the rods 30 may be extended beyond the end plate 33 or 34 and the extended portions utilized to eiect precision location of the entire assembly in the apparatus with which it is intended to be used.
  • the multiple head is extremely compact because of the extreme thinness of Yeach single-channel unit; the singlechannel units are so stacked and maintained in their assembly as to prevent misalignment; the individual units, being identical, are interchangeableyand the multiple heads themselves are of such construction as to enable interchangeability with like heads in the apparatus in which theyare intended to be used.
  • a multiple magnetic recording and play-back head comprising: an assembly of superposed units, each including :a magnetizable core providing pole pieces spaced to dene a working gap, a coil Wound upon said core, contact members electrically connected, respectively, to the ends of said coil, and support plates, having substantially greater mass than said core, bonded, respectively, to opposite sides of said core and said contact members, said plates incorporating recesses receptive of said coil, and bosses engaging said contact members; a magnetizable core providing pole pieces spaced to dene a working gap, a coil Wound upon said core, contact members electrically connected, respectively, to the ends of said coil, and support plates, having substantially greater mass than said core, bonded, respectively, to opposite sides of said core and said contact members, said plates incorporating recesses receptive of said coil, and bosses engaging said contact members; a magnetizable core providing pole pieces spaced to dene a working gap, a coil Wound upon said core, contact members electrically connected, respectively, to the ends
  • a multiple magneticrecording and play-back head comprising: an assembly of superposed units, each including a magnetizable core providing pole pieces spaced to dene a Working gap, a coil Wound upon said core, contact members electrically connected, respectively, to the ends of said coil, ⁇ and support plates bonded, respectively, to opposite sides of said core and said'contact members; and ia plurality of guide rods passing through apertures in said cores and Said plates to maintainsaid assembly of units in xed inter-relationship; the apertures in said cores being smaller than the apertures in said plates and providing a precise lit with said guide rods.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Magnetic Heads (AREA)

Description

June 19, 1956 J, E, DE TURK ET AL 2,751,440
MAGNETIC RECORDING-PLAY-BACK HEADS Filed July 22, 1950 2 Sheets-Sheet' 1 nr EY June 19, 1956 J. E. DE TURK ET A1. 2,751,440
MAGNETIC REcoRnmG-PLAY-BACK HEADS 2 Sheets-Sheet 2 Filed July 22 1950 Y /,9 2a .Jllll l' l l FVG. 4-
/A/l/E A/ 7' 0195 JOHN E. aTl/EK J/M/ hf Mac-NEILL United States Patent O MAGNETC 4RECORDING-PLAY-BACK VHEADS Jo'hnE. ADe'lurk, Cambridge, John H. MacNell, Stoughton, and Norman TEliot Gibbs, Waltham, Mass., assignors to Raytheon.Manufacturing Company, Newton, fMass., a corporationof Delaware Application July 22, 1950, SerialNo. 175,402
2 Claims. (Cl. 179-1001) This `invention relates to magnetic .recording and playback heads, and more particularly .to devices of the general character indicated especially adapted for simultaneous .multiple-channel operation.
Existing .devices of this type possess certain-disadvantages. For example, they are bulky; Athey require eX- treme accuracy in their fabrication .and assembly; -they arediicult to replace without risk of loss of synchronism of theinformation recorded on the various channels; and .they are disturbed by an undue amount of cross-talk between said channels.
It is, therefore, the main object .of .the present `invention to eliminate the foregoing disadvantages by providing a head which consists of a plurality-of thin, stacked, single-channel umts which are complete in themselves, which -carry .their own terminals, Aand which maintain proper inter-relationship for their entire useful lives.
:It is another object of the present invention to provide a multiple 'head in which each single-channel unit is a duplicate of each other unit, whereby the single units are interchangeable within a particular multiple head, and the multiple heads are likewise interchangeable in the apparatus in which they are employed.
It is still another object of the present invention to provide a multiple head which requires greatly diminished accuracy in the mounts adapted to receive the same in the apparatus in which they are employed.
It is still another object of the present invention to provide a multiple head which is extremely compact and still incorporates effective shielding for reducing interchannel interference to acceptable limits.
These and other objects of the present invention, which will become more apparent as the detailed description thereof progresses, are attained, broadly, in the following manner.
A magnetizable core provided with pole pieces spaced by a non-magnetic insert to define a working gap has a coil wound thereon. The coil has its ends electrically connected, respectively, to Contact members. Bonded to the side surfaces of the core and contact members are duplicate plastic plates, said plates being provided with recesses receptive of the windings on the core and bosses engaging contact members. The units thus far described are stacked with magnetic shields therebetween and the assembly is held together and maintained in fixed interrelau'onship by locating rods passing through apertures in the shields, side plates and cores.
Magnetic heads embodying the features of the present invention have been constructed and found to have the advantages previously referred to, said advantages having been long sought, for example, in digital computing equipment and data filing systems. The chief virtue of the heads of the present invention is their extreme thinness, heads of .070 inch having been constructed whih permit eticient employment of the medium on which the recording is accomplished.
In the accompanying specification there shall be described, and in the annexed drawings shown, an illusl 2,751,440 Patented June 19, 1956 trative embodiment of the lmagnetic recording-play-back head of the present invention. vIt is, however, to be clearly Aunderstood-that the present invention is not to be limited to 'the Vexact details herein shown and described for purposes of illustration only, inasmuch as changes therein may be `made without the exercise of invention and within the true Aspirit and scope of the claims Vhereto appended.
In -said drawing:
Fig. 4l is an'exploded side elevational view showing the components making up each single-channel unit;
Fig. 2 is aside elevational view of a partially assembled single-channel unit;
Fig. 3 is a similar view of the same completely assembled; and
Fig. 4 is an edge view of an assembled multiple head incorporating a plurality of the single-channel units shown in Fig. 3.
Referring now more in detail to the aforesaid illustrative embodiment of the present invention, with particular referencetto Figs. l, V2 and 3 of the drawings, the numeral 10 generally designates a dat magnetizable core consisting-of amain rectangular portion 1l, a transverse, substantially'rectangular portion 12 at one end of said main portion, and a transverse, substantially triangular portion 13 at the other end of said main portion. As will hereinafter be more fully-described, two such cores are employed, the rectangular portions 12 having abutting inner surfaces 14 to complete the magnetic circuit, and the `triangular portions 1.3, constituting pole pieces, having flattened portions -ISYadapted to support an insert 16 of nomnagnetic material therebetween to dene a working'gap.
v'Each 'of the-'cores 10 has a coil 17 wound on the'main portion 11 thereof, the coils being series-connected by splicing together the lower ends thereof, as at 1S, the upper, free ends thereof being connected, respectively, to contact members 19 and 20. The members 1g and 20 are substantially rectangular in shape, except that their side edges are curved inwardly, as at 21 and 22, lugs 23 depending from the lower edges thereof, and olf-set tongues 24 extending from the upper edges thereof.
A pair of substantially rectangular plastic side plates 25, having rectangular openings 26 separated by elongated bosses 27, is bonded to the side surfaces of the cores 10, the openings 26 being receptive of the coils 17 wound upon said cores. The plates 25 are also bonded to the side surfaces of the contact members 19 and 29, and, through the bosses 27 and 28, to each other, the curved edges 21 and 22 of said contact members engaging substantially elliptical bosses 28 formed on said plates, whereby said contact members are maintained in appropriate alignment.
Fig. 2 of the drawing most clearly shows the cores and contact members in position on one of the side plates, and it is to be noted that said cores and contact members lie in a common plane. The single-channel unit completed by the addition of a second side plate, the completed unit being most clearly shown in Fig. 3 of the drawings.
As best seen in Fig. 4 of the drawings, a plurality of the units shown in Fig. 3 are stacked together with magnetic shields 29 between each pair, the assembly being held together and maintained in proper inter-relationship by locating rods 30 passing through openings 31 in the side plates 25, openings 32 in the cores 10, and, of course, aligned openings (no reference characters) in the shields 29. The openings 32 are accurately located with respect to the surfaces 14 and 15, the openings 31 are slightly larger than the openings 32, and the rods 30 t the openings 32 precisely, so that, when the units are stacked as aforesaid, all of the abutting surfaces 14 and the working "ice gaps become accurately aligned with respect to each other and with respect to the rods 30. The assembly is completed by suitable end plates 33 and 34.
If desired, the rods 30 may be extended beyond the end plate 33 or 34 and the extended portions utilized to eiect precision location of the entire assembly in the apparatus with which it is intended to be used.
This completes the description of the aforesaid illustrative embodiment of the magnetic recording and playback heads of the present invention.
It will be noted from all of the foregoing that the multiple head is extremely compact because of the extreme thinness of Yeach single-channel unit; the singlechannel units are so stacked and maintained in their assembly as to prevent misalignment; the individual units, being identical, are interchangeableyand the multiple heads themselves are of such construction as to enable interchangeability with like heads in the apparatus in which theyare intended to be used.
Other objects and advantages of the device of the present invention will readily occur to those skilled in the art to which the same relates.
What is claimed is:V
1. A multiple magnetic recording and play-back head comprising: an assembly of superposed units, each including :a magnetizable core providing pole pieces spaced to dene a working gap, a coil Wound upon said core, contact members electrically connected, respectively, to the ends of said coil, and support plates, having substantially greater mass than said core, bonded, respectively, to opposite sides of said core and said contact members, said plates incorporating recesses receptive of said coil, and bosses engaging said contact members; a
magnetic shield, substantially coextensive with said plates, disposed intermediate each pair of said units; and a plurality of guide rods passing through apertures in said cores, plates and shields to maintain said units in fixed 4V inter-relationship, with said Working gaps in alignment with each other. t
2. A multiple magneticrecording and play-back head comprising: an assembly of superposed units, each including a magnetizable core providing pole pieces spaced to dene a Working gap, a coil Wound upon said core, contact members electrically connected, respectively, to the ends of said coil, `and support plates bonded, respectively, to opposite sides of said core and said'contact members; and ia plurality of guide rods passing through apertures in said cores and Said plates to maintainsaid assembly of units in xed inter-relationship; the apertures in said cores being smaller than the apertures in said plates and providing a precise lit with said guide rods.
References Cited in the file of this patent UNITED STATES PATENTS 2,195,192 Y Schuller Mar. 26, 1940 2,456,767 Camras Dec. 21, 1948 2,493,742 Begun Ian. 10, 1950 2,513,617 Begun July 4, 1950 2,513,653 Kornei f July 4,/1950 2,517,808 Sziklai Aug. 8, 1950 2,523,576 Kornei Sept. 26, 1950 2,535,480 Begun Dec. 26, 1950 2,536,272 Friend Jan. 2, 1951 2,538,405 Zenner Jan. 16, 1951 2,540,654 Cohen Feb. 6, 1951 2,549,771 Camras Apr. 24, 1951 2,551,935 Flood May 8, 1951 2,563,445 Zenner Aug. 7, 1951 2,574,707 Pettus Nov. 13, 1951 2,574,898 Behren Nov. 13, 1951 2,590,292 Anderson Mar. 25, 1952 2,618,709 Eckert Nov. 18, 1952,
US175402A 1950-07-22 1950-07-22 Magnetic recording-play-back heads Expired - Lifetime US2751440A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US175402A US2751440A (en) 1950-07-22 1950-07-22 Magnetic recording-play-back heads

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US175402A US2751440A (en) 1950-07-22 1950-07-22 Magnetic recording-play-back heads

Publications (1)

Publication Number Publication Date
US2751440A true US2751440A (en) 1956-06-19

Family

ID=22640098

Family Applications (1)

Application Number Title Priority Date Filing Date
US175402A Expired - Lifetime US2751440A (en) 1950-07-22 1950-07-22 Magnetic recording-play-back heads

Country Status (1)

Country Link
US (1) US2751440A (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2916560A (en) * 1955-07-30 1959-12-08 Mathez Robert Sound head of a magnetic tape recorder
US2921143A (en) * 1955-05-31 1960-01-12 Ampex Multiple channel head assembly
US2923779A (en) * 1953-11-02 1960-02-02 Epsylon Res & Dev Co Ltd Electro-magnetic recording heads
US3047674A (en) * 1959-03-31 1962-07-31 Astatic Corp Recording and reproducing head for magnetic tape
US3065311A (en) * 1958-09-15 1962-11-20 Ibm Magnetic transducer
US3069755A (en) * 1955-11-21 1962-12-25 Texas Instruments Inc Method for making multi-unit electromagnetic head
US3080642A (en) * 1956-02-06 1963-03-12 John P Woods Method of manufacturing magnetic recording heads
US3327313A (en) * 1955-08-23 1967-06-20 Ncr Co Multiple head unit
JPS5121721Y1 (en) * 1970-04-20 1976-06-05

Citations (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2195192A (en) * 1938-11-23 1940-03-26 Licentia Gmbh Sound translating apparatus
US2456767A (en) * 1945-11-29 1948-12-21 Armour Res Found Combination of magnetic transducing and erasing heads
US2493742A (en) * 1945-08-22 1950-01-10 Brush Dev Co Magnetic transducing core for magnetic record transducers
US2513653A (en) * 1947-01-22 1950-07-04 Brush Dev Co Magnetic record transducing head
US2513617A (en) * 1946-08-06 1950-07-04 Brush Dev Co Magnetic recording and reproducing
US2517808A (en) * 1948-12-22 1950-08-08 Rca Corp Image recording and reproducing apparatus
US2523576A (en) * 1946-08-02 1950-09-26 Kornei Otto Ring-type magnetic recordtransducing head
US2535480A (en) * 1945-08-27 1950-12-26 Brush Dev Co Magnetic recording and reproducing
US2536272A (en) * 1948-12-02 1951-01-02 Rca Corp Magnetic recording-reproducing head
US2538405A (en) * 1948-04-27 1951-01-16 Armour Res Found Electromagnetic transducer head assembly
US2540654A (en) * 1948-03-25 1951-02-06 Engineering Res Associates Inc Data storage system
US2549771A (en) * 1946-08-16 1951-04-24 Armour Res Found Magnetic transducer head
US2551935A (en) * 1947-04-24 1951-05-08 Plastic Wire & Cable Corp Electrical attachment plug
US2563445A (en) * 1951-08-07 Mount for magnetic transducing
US2574707A (en) * 1948-12-29 1951-11-13 Rca Corp Magnetic head and mount therefor
US2574898A (en) * 1947-12-06 1951-11-13 Indiana Steel Products Co Electromagnetic transducer head assembly
US2590292A (en) * 1949-11-01 1952-03-25 Rca Corp Shielded magnetic sound-head and tape-guide assembly
US2618709A (en) * 1949-07-16 1952-11-18 Eckert Mauchly Comp Corp Cylindrical contact magnetic head

Patent Citations (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2563445A (en) * 1951-08-07 Mount for magnetic transducing
US2195192A (en) * 1938-11-23 1940-03-26 Licentia Gmbh Sound translating apparatus
US2493742A (en) * 1945-08-22 1950-01-10 Brush Dev Co Magnetic transducing core for magnetic record transducers
US2535480A (en) * 1945-08-27 1950-12-26 Brush Dev Co Magnetic recording and reproducing
US2456767A (en) * 1945-11-29 1948-12-21 Armour Res Found Combination of magnetic transducing and erasing heads
US2523576A (en) * 1946-08-02 1950-09-26 Kornei Otto Ring-type magnetic recordtransducing head
US2513617A (en) * 1946-08-06 1950-07-04 Brush Dev Co Magnetic recording and reproducing
US2549771A (en) * 1946-08-16 1951-04-24 Armour Res Found Magnetic transducer head
US2513653A (en) * 1947-01-22 1950-07-04 Brush Dev Co Magnetic record transducing head
US2551935A (en) * 1947-04-24 1951-05-08 Plastic Wire & Cable Corp Electrical attachment plug
US2574898A (en) * 1947-12-06 1951-11-13 Indiana Steel Products Co Electromagnetic transducer head assembly
US2540654A (en) * 1948-03-25 1951-02-06 Engineering Res Associates Inc Data storage system
US2538405A (en) * 1948-04-27 1951-01-16 Armour Res Found Electromagnetic transducer head assembly
US2536272A (en) * 1948-12-02 1951-01-02 Rca Corp Magnetic recording-reproducing head
US2517808A (en) * 1948-12-22 1950-08-08 Rca Corp Image recording and reproducing apparatus
US2574707A (en) * 1948-12-29 1951-11-13 Rca Corp Magnetic head and mount therefor
US2618709A (en) * 1949-07-16 1952-11-18 Eckert Mauchly Comp Corp Cylindrical contact magnetic head
US2590292A (en) * 1949-11-01 1952-03-25 Rca Corp Shielded magnetic sound-head and tape-guide assembly

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2923779A (en) * 1953-11-02 1960-02-02 Epsylon Res & Dev Co Ltd Electro-magnetic recording heads
US2921143A (en) * 1955-05-31 1960-01-12 Ampex Multiple channel head assembly
US2916560A (en) * 1955-07-30 1959-12-08 Mathez Robert Sound head of a magnetic tape recorder
US3327313A (en) * 1955-08-23 1967-06-20 Ncr Co Multiple head unit
US3069755A (en) * 1955-11-21 1962-12-25 Texas Instruments Inc Method for making multi-unit electromagnetic head
US3080642A (en) * 1956-02-06 1963-03-12 John P Woods Method of manufacturing magnetic recording heads
US3065311A (en) * 1958-09-15 1962-11-20 Ibm Magnetic transducer
US3047674A (en) * 1959-03-31 1962-07-31 Astatic Corp Recording and reproducing head for magnetic tape
JPS5121721Y1 (en) * 1970-04-20 1976-06-05

Similar Documents

Publication Publication Date Title
US2756280A (en) Multiple magnetic head construction
US2535480A (en) Magnetic recording and reproducing
US2915812A (en) Method of constructing magnetic heads
US2785038A (en) Magnetic transducer
US2272821A (en) Telegraphone
US2751440A (en) Magnetic recording-play-back heads
US3700827A (en) Magnetic head including thin magnetic film separated by a gap spacer
US2700588A (en) Digital computing machine
US2523576A (en) Ring-type magnetic recordtransducing head
US3327313A (en) Multiple head unit
US2618709A (en) Cylindrical contact magnetic head
US2658114A (en) Magnetic recording-reproducing device
US3222461A (en) Magnetic head construction
US2908770A (en) Magnetic recording-reproducing
US3311711A (en) Resilient core holder for pressing head sections into alignment
US2861135A (en) Magnetic heads and replaceable pole cap assemblies therefor
US2513617A (en) Magnetic recording and reproducing
US3157748A (en) Magnetic transducer
US2807676A (en) Magnetic head assemblies
GB801904A (en) Improvements in and relating to multi-channel transducer head assemblies
US2790966A (en) Magnetic recording and reproducing device
US2927974A (en) Magnetic transducer
US2848556A (en) Magnetic recording transducer
GB1423520A (en) Manufacture of magnetic transducing heads
US2655562A (en) Erasing head for magnetic recording