US2108275A - Electromagnetic device and method of making same - Google Patents

Electromagnetic device and method of making same Download PDF

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Publication number
US2108275A
US2108275A US16872A US1687235A US2108275A US 2108275 A US2108275 A US 2108275A US 16872 A US16872 A US 16872A US 1687235 A US1687235 A US 1687235A US 2108275 A US2108275 A US 2108275A
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US
United States
Prior art keywords
armature
pole
supporting surfaces
faces
electromagnetic device
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
US16872A
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English (en)
Inventor
Vermeulen Roelof
Arend Thomas Van Urk
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.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
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 Philips Gloeilampenfabrieken NV filed Critical Philips Gloeilampenfabrieken NV
Application granted granted Critical
Publication of US2108275A publication Critical patent/US2108275A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R11/00—Transducers of moving-armature or moving-core type
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R11/00—Transducers of moving-armature or moving-core type
    • H04R11/08—Gramophone pick-ups using a stylus; Recorders using a stylus

Definitions

  • the present invention relates to electromagnetic devices and to methods of making same, and pertains more particularly to electromagnetic-acoustic devices.
  • the invention will be described in connection with electromagnetic sound devices for recording, but can be also applied to reproducing devices, etc.
  • Devices according to the invention are espe- 10 cially well adapted for use in the method of sound recording described in U. S. Patent No. 1,919,116 to J. A. Miller.
  • the pole pieces of the device are rigidly secured to members of nonmagnetic material, which members are provided with surfaces upon which the armature is suspended; the pole faces and the surfaces of suspension lying in the same plane.
  • pole pieces be rigidly secured to the members of nonmagnetic material so that their relative position thereto will not be influenced by shock and vibration, and it is preferable that the pole faces and the suspension surfaces be finished in one operation so as to lie in the same plane.
  • the armature and its means of suspension form a single piece of magnetic material of uniform thickness.
  • the armature is mounted on the surface of the nonmagnetic member to which the pole piece is secured, with the interposition of suitable spacers.
  • the distance between the armature and the pole piece is governed only by the thickness of the spacer.
  • Figure 1 is a side elevation of an electromagnetic recorder in accordance with the invention partly sectionized along line II of Fig. 2;
  • Figure 2 is a side view of Figure 1 partly sectionized along the line 11-11 of Fig. 1;
  • Fig. 3 is a partly sectionized plan view of the 5 recorder shown in Figure l with the upper pole piece assembly removed;
  • Fig. 4 is a perspective view of one of the pole pieces shown in Figs. 1 and. 2, and
  • Fig. 5 is an exploded perspective view of the 10 recorder of Fig. 1 with the coils omitted for simplicity.
  • the electromagnetic recorder consists of two pole piece assemblies AA, each comprising a U-shaped member E of nonl5 magnetic material, for instance copper, and is provided with two plane end-faces 9-9 servin to support an armature l of magnetic material. Rigidly secured to each of the members '
  • the pole faces 8-8 and the faces 9-9 5 are finished so as to lie in the same plane, this being preferably effected in a single operation, for instanceby somilling or grinding the faces 88 and 9-9 that they lie exactly in the same plane.
  • the armature I (see Figs. 3 and 5) is formed of 39 a flat piece of magnetic material of uniform thickness, for instance of soft iron. Its central portion 2 is substantially square and projects on one side in a centrally extension 3, to which a recording cutter or needle I6, is removably se- 35 cured by means of a screw H.
  • the square 2 of the armature I extends on each side into narrow neck portions 4-4 to end in two rectangular suspension portions 5-5 which are provided with clearance holes 2ll2ll. 40
  • the portions 4-4 serve to provide the torsional forces to the armature; when in operation the armature portion 2 tends to vibrate about the longitudinal axis of the portions 44.
  • the coils l2l2 Arranged one on each side of the portions 4-4 and encircling the portion 2 with a clearance sufficient to prevent any contact therewith, are two coils l2l2.
  • 2l2 carry the impressed amplified current, whereas for reproducing devices such coils carry the induced current. In either case the coils may be in series or in parallel.
  • the coils l2--l2 are secured in a fixed position, for example by means of a wooden wedge I3,
  • the pole piece assemblies AA are arranged with their respective faces 99 opposing each other with the interposition of the armature l; the latter being spaced from the faces 99 by spacers ID.
  • the whole device is secured together into a rigid unit by four bolts I I, passing through the clearance holes 20 of the armature, and through corresponding bores in the members 1---! and in spacers ID.
  • the distance between the surfaces of the armature portion 2 and the pole faces 88 is determined by the thickness of the spacers I[ll0, and due to this the device may be quickly and accurately assembled or taken apart and reassembled Without requiring special tools or skill.
  • the armature I should be comparatively rigid and for this purpose, as has been shown, is made integral with its means of suspension and has the same thickness. However, in other electromagnetic devices, for instance loudspeakers, the armature is preferably suspended in a less rigid manner.
  • the portions shown as 44 and 5--5 can be made of different material from that of the central portions 2, whereby portions 4-4 and 55 are rigidly secured to the central portion, for instance by soldering or welding.
  • the magnetic field in which the armature vibrates may be supplied by a permanent magnet l4, secured in good magnetic contact with the pole pieces 6-6 by means of screws 15-15. While the magnet I4 is shown as having the shape of a bar, magnets of other shapes, for example horseshoe magnets, may be also used. Instead of using a permanent magnet, an electromagnet may also be used, in which case a source of supply for energizing the electromagnet is required.
  • An electromagnetic device comprising, a coil, means for producing a magnetic field, a member of non-magnetic material having supporting surfaces lying in a common plane, a pole piece rigidly secured to said member and having pole faces lying in the plane of said supporting surfaces, an armature adjacently disposed to said pole faces, and means for suspending said armature from the supporting surfaces of said member.
  • An electromagnetic device comprising, a coil, means for producing a magnetic field, a member of non-magnetic material having supporting surfaces lying in a common plane, a pole piece rigidly secured to said member and having pole faces lying in the plane of said supporting surfaces, an armature disposed adjacent to said pole faces, and means including spacers for suspending the armature from the supporting surfaces of said member.
  • An electro-acoustic device for cutting a sound track on a film carrier comprising a coil, means for producing a magnetic field, a member of non-magnetic material having supporting surfaces lying in a common plane, a pole piece rigidly secured to said member and having pole faces lying in the plane of said supporting surfaces, an armature disposed adjacent to said pole faces, a cutting tool connected with said armature, and means for suspending said armature from the supporting surfaces of said member.
  • An electromagnetic device comprising a coil, means for producing a magnetic field, two members of non-magnetic material having supporting surfaces, the supporting surfaces of each member lying in a common plane, a pole piece rigidly secured to each of said members and having pole faces lying in the plane of the supporting surfaces of their respective member, an armature disposed adjacent to said pole faces, and means for flexibly suspending said armature from the supporting surfaces of said member, said means being clamped between the supporting surfaces of said members.
  • An electromagnetic device comprising a coil, means for producing a magnetic field, a member of non-magnetic material having supporting surfaces lying in a common plane, a pole piece rigidly secured to said member and having pole faces lying in the plane of said supporting surfaces, a flat piece of magnetic material of uniform thickness suspended from the supporting surfaces of said member with the interposition of spacers, said fiat piece serving as an armature and as a flexible suspension therefor.
  • An electromagnetic device comprising a coil, means for producing a magnetic field, two U- shaped members of non-magnetic material, each member having two supporting surfaces lying in a common plane, a pole piece rigidly secured to each of said members and having two pole faces lying in the plane of the supporting surface of its respective non-magnetic member, a fiat piece of magnetic material having a uniform thickness, said piece having an armature portion, suspension portions and intermediate torsional portions, spacers between said suspension portions and the supporting surfaces of said non-magnetic members to space the armature portion from said pole faces, and means for clamping said non-magnetic members, spacers and flat piece together.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
US16872A 1934-05-17 1935-04-17 Electromagnetic device and method of making same Expired - Lifetime US2108275A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE441747X 1934-05-17

Publications (1)

Publication Number Publication Date
US2108275A true US2108275A (en) 1938-02-15

Family

ID=6518428

Family Applications (1)

Application Number Title Priority Date Filing Date
US16872A Expired - Lifetime US2108275A (en) 1934-05-17 1935-04-17 Electromagnetic device and method of making same

Country Status (5)

Country Link
US (1) US2108275A (zh)
BE (1) BE409329A (zh)
FR (1) FR789737A (zh)
GB (1) GB441747A (zh)
NL (1) NL43098C (zh)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2444336A (en) * 1946-01-30 1948-06-29 Lionel B Cornwell Electrical sound translating device
US2454425A (en) * 1943-12-23 1948-11-23 Shure Bros Magnetic translating device
US2498671A (en) * 1945-01-26 1950-02-28 Int Standard Electric Corp Sound reproducer or recorder head

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2454425A (en) * 1943-12-23 1948-11-23 Shure Bros Magnetic translating device
US2498671A (en) * 1945-01-26 1950-02-28 Int Standard Electric Corp Sound reproducer or recorder head
US2444336A (en) * 1946-01-30 1948-06-29 Lionel B Cornwell Electrical sound translating device

Also Published As

Publication number Publication date
NL43098C (zh)
FR789737A (fr) 1935-11-05
GB441747A (en) 1936-01-24
BE409329A (zh)

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