US3864753A - Transducer head with spacer material made of stainless steel - Google Patents

Transducer head with spacer material made of stainless steel Download PDF

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Publication number
US3864753A
US3864753A US358698A US35869873A US3864753A US 3864753 A US3864753 A US 3864753A US 358698 A US358698 A US 358698A US 35869873 A US35869873 A US 35869873A US 3864753 A US3864753 A US 3864753A
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US
United States
Prior art keywords
stainless steel
transducer head
tape
tracking circuits
magnetic
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
US358698A
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English (en)
Inventor
Robert Sidney Becker
Eric Frank Painter
Gerrard Charles Rickard
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.)
GRESHAM INFOMAG Ltd
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GRESHAM INFOMAG Ltd
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.)
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Publication date
Application filed by GRESHAM INFOMAG Ltd filed Critical GRESHAM INFOMAG Ltd
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Publication of US3864753A publication Critical patent/US3864753A/en
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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
    • G11B5/187—Structure or manufacture of the surface of the head in physical contact with, or immediately adjacent to the recording medium; Pole pieces; Gap features
    • G11B5/255—Structure or manufacture of the surface of the head in physical contact with, or immediately adjacent to the recording medium; Pole pieces; Gap features comprising means for protection against wear
    • 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
    • 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
    • G11B5/295—Manufacture

Definitions

  • An electromagnetic transducer head comprises a plurality of magnetic tracking circuits with screening Foreign Application ity ata means between the individual circuits and in order to May 9, 1972
  • Great Britain 21638/72 overcome the adverse effects of differential wear as between the magnetic circuit pole pieces and the in- [52]
  • U.S. Cl 360/121, 360/122, 360/125 termediate spacer material used is made of stainless [51] Int. Cl Gllb S/12, G1 lb 5/22, G1 lb 5/26 steel in place of the conventional non-magnetic mate- [58] Field of Search l79/l00.2 C, 100.2 MD; rials such as brass, aluminium and plastics materials.
  • the tracking circuits may be fitted into slots in a stain- 122 less steel blank or a blank of conventional nonmagnetic material may be used with stainless steel [56] References Cited spacers fitted in between the tracking circuits.
  • This invention relates generally to electromagnetic transducer heads, and is more particularly concerned with tape recording and/or playback heads.
  • a body blank of brass, aluminium, or a suitable plastics material is grooved to hold a plurality of magnetic circuits comprising pole pieces each carrying an electrical winding.
  • the body blank is additionally grooved between each of the grooves carrying the magnetic circuits, and into these additional grooves are fitted screens, for example of a magnetic alloy such as Mumetal.
  • screens for example of a magnetic alloy such as Mumetal.
  • This conventional construction has been found to have considerable disadvantages when used with magnetic tape due t the differential wear rate as between the magnetic circuit pole pieces and the intermediate spacer material such as brass, aluminium, or plastics material for example.
  • This differential wear has the effect of causing the surface of the magnetic circuit pole pieces over which the tape moves to become concave.
  • this also causes the coating of the tape to be damaged, resulting in tape wear and the deposition of oxide particles on to the transducing head.
  • an electromagnetic transducer head comprising a body blank having a surface over which a tape is adapted to pass, a plurality of magnetic tracking circuits supported in said blank each with a pole piece face flush with said surface, and screening means between the respective tracking circuits, characterised in that the land areas between the tracking circuits and over which the tape is adapted to pass are at least partially of stainless steel.
  • the body blank is of stainless steel and is grooved to receive said tracking circuits and screening means.
  • the body blank is of nonmagnetic material and has inserts at least partially of stainless steel fitted therein between the tracking circuits.
  • the land area between each pair of adjacent tracking circuits is of stainless steel adjacent to each tracking circuit with said screening means substantially midway between the tracking circuits.
  • FIG. 1 is a plan view of the two body parts of a singlegap recording head with a gap spacer indicated schematically therebetween;
  • FIG. 2 is a side view of one of the body parts of FIG. 1 taken to the line AA of FIG. 1;
  • FIG. 3 is a sectional view of one of the body parts of FIG. 1 taken along the line BB of FIG. 1;
  • FIG. 4 is a schematic illustration of a modified embodiment of transducing head in accordance with the invention.
  • FIG. 5 is a schematic representation of a modified form of spacer for use with the embodiment shown in FIG. 4.
  • FIG. 1 shows schematically the two basic body parts of a recording/playback transducer head which when assembled together and secured by dowel pins and screws have a gap spacer positioned therebetween.
  • the two body parts are indicated generally at 10 and 11, the gap spacer at 12, and an associated magnetic tape is shown at 13, the arrows indicating its direction of movement over the head.
  • the body part 10 for example, (the body part 11 is the same in construction and is therefore not separately described) this comprises a body blank which is first provided with a plurality of parallel slots 14 into which screens 16 of a magnetic alloy, such as Mumetal for example, are fitted. Wider but shallower slots 18 are then out between each pair of screen slots 14 and receive individual magnetic tracking circuits as shown more clearly in FIGS. 2 and 3.
  • the slots 14 and 18 are cut directly into the inside face 19 of the body blank.
  • Each of the magnetic tracking circuits comprises a pole piece 20 of a magnetic material such as Mumetal having a pole tip 22 and a heel 24.
  • Each pole piece 20 is formed by a stack of laminations and has a winding 26 formed around the central smaller cross-section portion.
  • the coil 26 is connected to terminal pins on a terminal board 28.
  • the body blank 10 (and the body blank 11 also), which has conventionally been made of brass, aluminium, or a plastics materiahis made of stainless steel.
  • the slots 14 and 18 are machined into the stainless steel body blank with the result that the pole tips 22 of the pole pieces 20 are separated by land areas 30 of stainless steel divided by the screens 16. It has been found that this replacement of the conventional materials for the lands 30 between the tracking circuits by stainless steel has a most beneficial effect on the wear of the head, and in particular on the differential wear between the pole tips 22 and the lands 30. It also results in less damage to the tape 13 and in a reduction in the deposition of oxide particles from the tape on the head.
  • FIG. 4 shows an alternative embodiment of transducer head in accordance with the present invention which has the advantage as compared with the embodiment shown in FIGS. 1 to 3 that it is not necessary to machine the slots 14 and 18 in a stainless steel blank.
  • the body blank 10 of FIG. 4 is made of brass, aluminium, a plastics material, or any other suitable easily machinable material including those which are conventionally used.
  • a rectangular cross-section portion of the blank is first removed to a depth indicated by reference numeral 40 and then a plurality of relatively shallow grooves 41 are machined in this recessed body blank.
  • the individual magnetic tracking circuits comprising the pole pieces 20 are fitted between the grooves 41.
  • each of the spacers 46 is formed by the combination of a plurality of rectangular laminations of stainless steel, preferably the stainless steel alloy of the composition referred to above.
  • each of the spacers 46 includes a screen 48 of Mumetal for example, the screen preferably being at the centre of the spacer.
  • the screen 48 is of the same depth and height as the spacer laminations and may have a lateral dimension transversely of the direction of movement of the tape 13 approximately equal to one third of the overall lateral thickness of the spacer 46.
  • FIG. S- shows a modified form of spacer for use in an embodiment similar to that shown in FIG. 4 where, in order to accommodate the thickness of the windings 26 on the pole pieces 20 each spacer 50 comprises a Mumetal screen 52 which is provided with stainless steel spacer laminations 53 only at its ends adjacent to the pole tip 22 and heel 24 of the pole pieces.
  • a separate, or additional, improvement is obtained in certain configurations of magnetic circuit and spacer size ratios, by replacing a number of magnetic circuit laminations with stainless steel laminations, for example every fifth lamination of the stack.
  • the wear rate of the parts of the magnetic transducer head can be controlled for individual circumstances of utilisation to provide desired wear characteristics.
  • a multi-track tape electromagnetic transducer head comprising a body having a surface over which a tape is adapted to pass, a plurality of respective magnetic tracking circuits supported in said body and each having a pole piece having a face flush with and forming part of said surface, each said face contacting a respective longitudinally extending area of said tape for the transfer of information between the associated magnetic and the associated area of the tape, characterised in that said surface is at least partially of stainless steel between said magnetic tracking circuits.
  • a multi-track electromagnetic transducer head comprising a body blank having a surface over which a tape is adapted to pass in contact with said surface, a plurality of respective magnetic tracking circuits supported in said blank and each having a pole piece having a face flush with and forming part of said surface, each said face contacting a respective longitudinally extending area of said tape for the transfer of inform ation between the associated magnetic circuit and the associated area of the tape, screening means between the respective tracking circuits, and land areas between the tracking circuits and forming parts of said surface, the improvement comprising said land areas being formed of stainless steel.
  • each insert comprises a screening plate co-extensive with the adjacent tracking circuits and portions of stainless steel on each side of the screening plate adjacent to said pole piece faces with a gap therebelow to accommodate windings on the tracking circuit pole pieces.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Magnetic Heads (AREA)
US358698A 1972-05-09 1973-05-09 Transducer head with spacer material made of stainless steel Expired - Lifetime US3864753A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2163872A GB1416534A (en) 1972-05-09 1972-05-09 Transducer head

Publications (1)

Publication Number Publication Date
US3864753A true US3864753A (en) 1975-02-04

Family

ID=10166312

Family Applications (1)

Application Number Title Priority Date Filing Date
US358698A Expired - Lifetime US3864753A (en) 1972-05-09 1973-05-09 Transducer head with spacer material made of stainless steel

Country Status (7)

Country Link
US (1) US3864753A (xx)
JP (1) JPS4962117A (xx)
DE (1) DE2323402A1 (xx)
FR (1) FR2184028B3 (xx)
GB (1) GB1416534A (xx)
IT (1) IT988179B (xx)
NL (1) NL7306398A (xx)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4170033A (en) * 1977-03-15 1979-10-02 Data Recording Instrument Company Limited Multi-track head with shielding elements interconnected with low resistance conductive paths
US4791718A (en) * 1985-09-27 1988-12-20 Kabushiki Kaisha Sankyo Seiki Seisakusho Method for assembling a magnetic head
WO1994018671A1 (en) * 1993-02-12 1994-08-18 Datacard Corporation Magnetic stripe read/write head
EP1184843A2 (en) * 2000-09-01 2002-03-06 Hewlett-Packard Company Head assembly
US20110182792A1 (en) * 2008-09-24 2011-07-28 Kimihito Suzuki Method for producing catalyst reforming tar-containing gas, method for reforming tar and method for regenerating catalyst for reforming tar-containing gas

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5219020A (en) * 1975-08-04 1977-01-14 Nippon Telegr & Teleph Corp <Ntt> Tertial distortion offsetting equipment

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2839614A (en) * 1953-06-18 1958-06-17 Leslie C Merrill Magnetic recording head
US2895015A (en) * 1953-09-17 1959-07-14 Rca Corp Magnetic record transducer
US3053940A (en) * 1957-05-20 1962-09-11 Thompson Ramo Wooldridge Inc Electromagnetic head
US3064333A (en) * 1959-06-29 1962-11-20 Ibm Method of making a magnetic transducer
US3316359A (en) * 1963-05-20 1967-04-25 Winston Res Corp Transducer head utilizing electro-magnetic shielding for cross-talk elimination
US3404242A (en) * 1965-06-14 1968-10-01 Hewlett Packard Co Magnetic head holding element

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2839614A (en) * 1953-06-18 1958-06-17 Leslie C Merrill Magnetic recording head
US2895015A (en) * 1953-09-17 1959-07-14 Rca Corp Magnetic record transducer
US3053940A (en) * 1957-05-20 1962-09-11 Thompson Ramo Wooldridge Inc Electromagnetic head
US3064333A (en) * 1959-06-29 1962-11-20 Ibm Method of making a magnetic transducer
US3316359A (en) * 1963-05-20 1967-04-25 Winston Res Corp Transducer head utilizing electro-magnetic shielding for cross-talk elimination
US3404242A (en) * 1965-06-14 1968-10-01 Hewlett Packard Co Magnetic head holding element

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4170033A (en) * 1977-03-15 1979-10-02 Data Recording Instrument Company Limited Multi-track head with shielding elements interconnected with low resistance conductive paths
US4791718A (en) * 1985-09-27 1988-12-20 Kabushiki Kaisha Sankyo Seiki Seisakusho Method for assembling a magnetic head
WO1994018671A1 (en) * 1993-02-12 1994-08-18 Datacard Corporation Magnetic stripe read/write head
US5535078A (en) * 1993-02-12 1996-07-09 Data Card Corporation Magnetic multi-track read/write head with recessed core gap structure and shield arrangement
EP1184843A2 (en) * 2000-09-01 2002-03-06 Hewlett-Packard Company Head assembly
EP1184843A3 (en) * 2000-09-01 2003-02-05 Hewlett-Packard Company Head assembly
US6639753B1 (en) 2000-09-01 2003-10-28 Hewlett-Packard Development Company, L.P. Method of forming a head assembly, a head assembly, and a linear tape drive
US20040125501A1 (en) * 2000-09-01 2004-07-01 Henze Richard H. Method of forming a head assembly, a head assembly, and a linear tape drive
US7111383B2 (en) * 2000-09-01 2006-09-26 Hewlett-Packard Development Company, L.P. Method of forming a head assembly
US20110182792A1 (en) * 2008-09-24 2011-07-28 Kimihito Suzuki Method for producing catalyst reforming tar-containing gas, method for reforming tar and method for regenerating catalyst for reforming tar-containing gas
US9090465B2 (en) * 2008-09-24 2015-07-28 Nippon Steel & Sumitomo Metal Corporation Method for producing catalyst reforming tar-containing gas, method for reforming tar and method for regenerating catalyst for reforming tar-containing gas

Also Published As

Publication number Publication date
IT988179B (it) 1975-04-10
GB1416534A (en) 1975-12-03
FR2184028A1 (xx) 1973-12-21
NL7306398A (xx) 1973-11-13
DE2323402A1 (de) 1973-12-13
JPS4962117A (xx) 1974-06-17
FR2184028B3 (xx) 1976-04-23

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