US2482860A - Core for electromagnets - Google Patents

Core for electromagnets Download PDF

Info

Publication number
US2482860A
US2482860A US634965A US63496545A US2482860A US 2482860 A US2482860 A US 2482860A US 634965 A US634965 A US 634965A US 63496545 A US63496545 A US 63496545A US 2482860 A US2482860 A US 2482860A
Authority
US
United States
Prior art keywords
core
armature
pole face
shell
paramagnetic
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
US634965A
Inventor
Miller Charles Frank
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.)
PRICE ELECTRIC Corp
Original Assignee
PRICE ELECTRIC CORP
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 PRICE ELECTRIC CORP filed Critical PRICE ELECTRIC CORP
Priority to US634965A priority Critical patent/US2482860A/en
Application granted granted Critical
Publication of US2482860A publication Critical patent/US2482860A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
    • H01F7/081—Magnetic constructions
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
    • H01F7/10—Electromagnets; Actuators including electromagnets with armatures specially adapted for alternating current
    • H01F7/12—Electromagnets; Actuators including electromagnets with armatures specially adapted for alternating current having anti-chattering arrangements
    • H01F7/1205—Electromagnets; Actuators including electromagnets with armatures specially adapted for alternating current having anti-chattering arrangements having short-circuited conductors

Definitions

  • the invention relates to improvements in electromagnets, and more particularly to encased cores formed of paramagnetic powders.
  • One of the objects of the invention is to provide a core having an interior cf insulated compressed powdered iron or other paramagnetic material which has been finely divided and then compressed in such a way as to obtain a high density and more or less complete insulation of the paramagnetic particles.
  • Another object of the invention is to provide a shading arrangement for a core made of paramagnetic powders.
  • Another feature of the invention resides in the provision of a core whose shaded end is slightly conical in form so as to cause the armature to strike the pole face at a single point or at a region of very small area.
  • Still another feature of the invention resides in the provision of a hard center for a core of powdered material so as to withstand the impact of the armature when the end of the pole is made conical to provide a single point of contact.
  • Fig. 1 is a side elevation of a portion of an encased core of powdered paramagnetic material shown as provided with a shading ring in one end thereof;
  • Fig. 1a is an end view of the same
  • Fig. lb is a longitudinal section
  • Fig. 2 is a view similar to Fig. 1b in which the shaded end of the core is made conical to provide a single point contact for the armature;
  • Fig. 3 discloses a further modification wherein the shaded end is provided with a hard center.
  • reference numeral I denotes an outer shell which may be made of paramagnetic material, such as iron tubing, or it may be made of other material, paramagnetic or otherwise. Paramagnetic material, however, is preferred.
  • the shell as shown is circular in cross section, but other shapes may be employed if desired, although a shell of circular cross section is for many purposes preferred.
  • the shell may, however, be of any shape and may be seamless, cr with any variety of slots, seams or perforations.
  • the primary purpose of the outer shell is to give the inner core mechanical strength, but it may also be used to give the core magnetic, electrical or mechanical characteristics.
  • the inner core is formed of innetic material which has been finely divided and then compressed in such a way as to obtain a high density and more or less complete insulation of the paramagnetic particles.
  • the primary function of this interior is to reduce loss due to eddy currents when the magnetic flux in the core varies with time, as in the case of a pulsating or alternating ilux, but this type of interior may be used to give the core special electrical, mechanical or magnetic characteristics. This type of construction is found to give excellent mechanical control in the design of magnets and results in low eddy current losses in applications where the magnetic ilux varies with time.V
  • the core is preferably provided with a shading ring l2, which may be formed of copper, brass or other highly conductive material.
  • the outer periphery of the shading ring preferably forms a tight fit within the inner wall of the shell.
  • the shaded end of the core (the pole face) may be turned or otherwise shaped so that a slightly conical end I3 results.
  • This turned pole face serves to cause the armature to strike the pole face at a single point or at a region of very small area.
  • this arrangement is desirable for the purpose of reducing chatter of the armature when the magnetizing force, is periogil-,gy
  • the hard center l of the pole face may be either of paramagnetlc material, such as iron, where the eiciency of the joint between the pole face and the amature is' important, or it may be of non-magnetic material serving to form a magnetic breaker where there is danger of sticking due to remnant magnetism at the pcini-I of contact.
  • the core may be either some hard metal of alloy, or may be non-metallic material such as carborundum or the like.
  • an electromagnet having an armature, a core for the electromagnet comprising a compact cylindrical mass oi finely divided insulated pressed powdered iron particles, one end of the cylindrical mass being shaped to provide a conical pole face to cause the armature of the magnet to strike the pole face at a region of very small area, and a hard center embedded within said core and extending beyond the conical pole face to provide a small region of contact and to withstand the impact of the armature.
  • a core for an electromagnet comprising an outer shell of paramagnetic material, an inner core of compressed nely divided insulated paramagnetic particles within the shell, and shading means embedded in the core at one end thereof comprising an insert of solid highly conductive metal closely itting within the outer shell adjacent one end thereof.
  • a core for an electromagnet comprising an outer shell of paramagnetic material, an inner core of compressed iinely divided insulated paramagnetic particles Within the shell, and shading means embedded in the core at one end thereof comprising an insert of solid highly conductive metal closely fitting within the outer shell adjacent one end thereof, said shading means comprising a copper ring.
  • a core for an electromagnet comprising a shell of paramagnetic material of circular cross section, compressed iinely divided paramagnetic particles within the shell, said core having a conical pole face, and a shading ring of highly conductive metal such as copper embedded within the core and closely tting within the outer shell at the pole end thereof.
  • a core for an electromagnet comprising a shell of paramagnetic material of circular cross section, compressed finely divided paramagnetlc particles within the shell, said core having a conical pole face, and a hard center embedded within said core and extending beyond the conical pole face to provide asmall region of contact.
  • a core for an electromagnet comprising a shell of paramagnetic material of circular cross section, compressed finely divided paramagnetic particles within the shell, said core having a conical pole face at one end thereof, a shading ring of highly conductive metal .such as copper embedded within said core and closely fitting within the outer shell at the pole end thereof, and a hard center embedded within said core and extending beyond the conical pole face to provide a small region of contact.
  • a core for an electromagnet comprislngan outer shell oi paramagnetic material, an inner core of insulated pressed powdered iron within the shell, said core having a pointed pole face at one end thereof, a shading ring of highly conductive metal embedded Within said core and snugly iitting Within the end of the shell adjacentv said pointed pole face, and a hard center embedded within said core and extending beyond the conical pole face to provide a small region of contact.
  • a core for yan electromagnet comprising a compact cylindrical mass of compressed powdered paramagnetic particles, said core having a conical pole face at one end thereof, and a hard center embedded Within said core having a pointed end forming the tip of said conical pole face.
  • an electromagnet having a movable armature, an elongated core comprising a compact mass of ilnely divided paramagnetic particles, said core having a pole face at one end for engagement with said armature, and a hard center embedded within said core and projecting beyond the mass of particles to provide a point of contact with said armature.
  • an electromagnet having a movable armature, an elongated core comprising a compact mass of inely divided paramagnetic particles, said core having a pole face at one end for engagement with said armature, and a hard center embedded within said core and projecting beyond the mass of particles to provide a point of contact with said armature, said hard center being composed of carborundum.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Electromagnets (AREA)

Description

Sept. 27, 1949. C, F, MlLLER 2,482,860
CORE FOR ELECTROMAGNETS Filed Dec. 14, '1945 PARA MA 6'4/67/0 SHLL SHA a nv 6 am@ of Cop/2E@ @ma as of? orme-R MAH-19ML sf/A' .o /N a R//va :E .LG- 1 b 00,96 aF coMpasss-o /Msa A reo PA/er/ cz is ARMA TURE l1-LET... E
Exif.. E
HA R o CsA/NFR ARMA TURE SWW Patented Sept. 27, 1949 CORE FOR ELECTROMAGNETS Charles Frank Miller, Frederick, Md., assignor to Price Electric Corporation, Frederick, Md.'
Application December 14, 1945, Serial No. 634,965
1o claims. 1
The invention relates to improvements in electromagnets, and more particularly to encased cores formed of paramagnetic powders.
One of the objects of the invention is to provide a core having an interior cf insulated compressed powdered iron or other paramagnetic material which has been finely divided and then compressed in such a way as to obtain a high density and more or less complete insulation of the paramagnetic particles.
Another object of the invention is to provide a shading arrangement for a core made of paramagnetic powders.
Another feature of the invention resides in the provision of a core whose shaded end is slightly conical in form so as to cause the armature to strike the pole face at a single point or at a region of very small area.
Still another feature of the invention resides in the provision of a hard center for a core of powdered material so as to withstand the impact of the armature when the end of the pole is made conical to provide a single point of contact.
The invention will be more readily understood by reference to the accompanying drawing and the following detailed description.
In the drawings:
Fig. 1 is a side elevation of a portion of an encased core of powdered paramagnetic material shown as provided with a shading ring in one end thereof;
Fig. 1a is an end view of the same;
Fig. lb is a longitudinal section;
Fig. 2 is a view similar to Fig. 1b in which the shaded end of the core is made conical to provide a single point contact for the armature;
Fig. 3 discloses a further modification wherein the shaded end is provided with a hard center.
Referring to the drawings, reference numeral I denotes an outer shell which may be made of paramagnetic material, such as iron tubing, or it may be made of other material, paramagnetic or otherwise. Paramagnetic material, however, is preferred. The shell as shown is circular in cross section, but other shapes may be employed if desired, although a shell of circular cross section is for many purposes preferred. The shell may, however, be of any shape and may be seamless, cr with any variety of slots, seams or perforations. The primary purpose of the outer shell is to give the inner core mechanical strength, but it may also be used to give the core magnetic, electrical or mechanical characteristics.
The inner core, indicated at l l, is formed of innetic material which has been finely divided and then compressed in such a way as to obtain a high density and more or less complete insulation of the paramagnetic particles. The primary function of this interior is to reduce loss due to eddy currents when the magnetic flux in the core varies with time, as in the case of a pulsating or alternating ilux, but this type of interior may be used to give the core special electrical, mechanical or magnetic characteristics. This type of construction is found to give excellent mechanical control in the design of magnets and results in low eddy current losses in applications where the magnetic ilux varies with time.V
The core is preferably provided with a shading ring l2, which may be formed of copper, brass or other highly conductive material. The outer periphery of the shading ring preferably forms a tight fit within the inner wall of the shell.
In the case of an alternating current magnet the pull on the armature passes through zero twice during each complete cycle of the alternating current carried by the magnet coil. The function of the shading ring isto produce an outof-phase magnetic flux at the interface between the armature and the shaded end of the magnet core. This ux passes through the shading ring into the armature and returns through the encasing tube of the powdered iron core and thus completely encircles the shading ring. As a result of the phase difference between the local flux produced by the shading ring and the main ux the pull on the armature never becomes zero. As a result the force of attraction between the armature and the pole face does not pass through zero twice per cycle as in the case of the unshaded arrangements.
As shown in Fig. 2 the shaded end of the core (the pole face) may be turned or otherwise shaped so that a slightly conical end I3 results. This turned pole face serves to cause the armature to strike the pole face at a single point or at a region of very small area. With the armature indicated diagrammatically at i4 hinged in the conventional manner this arrangement is desirable for the purpose of reducing chatter of the armature when the magnetizing force, is periogil-,gy
sulated pressed powdered iron or other paramagthe purpose of illustration, but it will be obvious aceaeeo that numerous modifications and variations may be resorted to without departing from the spirit of the invention.
The hard center l of the pole face may be either of paramagnetlc material, such as iron, where the eiciency of the joint between the pole face and the amature is' important, or it may be of non-magnetic material serving to form a magnetic breaker where there is danger of sticking due to remnant magnetism at the pcini-I of contact. If of non-magnetic material the core may be either some hard metal of alloy, or may be non-metallic material such as carborundum or the like.
I claim:
1. 1n an electromagnet having an armature, a core for the electromagnet comprising a compact cylindrical mass oi finely divided insulated pressed powdered iron particles, one end of the cylindrical mass being shaped to provide a conical pole face to cause the armature of the magnet to strike the pole face at a region of very small area, and a hard center embedded within said core and extending beyond the conical pole face to provide a small region of contact and to withstand the impact of the armature.
2. A core for an electromagnet comprising an outer shell of paramagnetic material, an inner core of compressed nely divided insulated paramagnetic particles within the shell, and shading means embedded in the core at one end thereof comprising an insert of solid highly conductive metal closely itting within the outer shell adjacent one end thereof.
3. A core for an electromagnet comprising an outer shell of paramagnetic material, an inner core of compressed iinely divided insulated paramagnetic particles Within the shell, and shading means embedded in the core at one end thereof comprising an insert of solid highly conductive metal closely fitting within the outer shell adjacent one end thereof, said shading means comprising a copper ring.
4. A core for an electromagnet comprising a shell of paramagnetic material of circular cross section, compressed iinely divided paramagnetic particles within the shell, said core having a conical pole face, and a shading ring of highly conductive metal such as copper embedded within the core and closely tting within the outer shell at the pole end thereof.
5. A core for an electromagnet comprising a shell of paramagnetic material of circular cross section, compressed finely divided paramagnetlc particles within the shell, said core having a conical pole face, and a hard center embedded within said core and extending beyond the conical pole face to provide asmall region of contact.
6. A core for an electromagnet comprising a shell of paramagnetic material of circular cross section, compressed finely divided paramagnetic particles within the shell, said core having a conical pole face at one end thereof, a shading ring of highly conductive metal .such as copper embedded within said core and closely fitting within the outer shell at the pole end thereof, and a hard center embedded within said core and extending beyond the conical pole face to provide a small region of contact.
.7. A core for an electromagnet comprislngan outer shell oi paramagnetic material, an inner core of insulated pressed powdered iron within the shell, said core having a pointed pole face at one end thereof, a shading ring of highly conductive metal embedded Within said core and snugly iitting Within the end of the shell adjacentv said pointed pole face, and a hard center embedded within said core and extending beyond the conical pole face to provide a small region of contact.
8. A core for yan electromagnet, comprising a compact cylindrical mass of compressed powdered paramagnetic particles, said core having a conical pole face at one end thereof, and a hard center embedded Within said core having a pointed end forming the tip of said conical pole face.
9. In an electromagnet having a movable armature, an elongated core comprising a compact mass of ilnely divided paramagnetic particles, said core having a pole face at one end for engagement with said armature, and a hard center embedded within said core and projecting beyond the mass of particles to provide a point of contact with said armature.
10. In an electromagnet having a movable armature, an elongated core comprising a compact mass of inely divided paramagnetic particles, said core having a pole face at one end for engagement with said armature, and a hard center embedded within said core and projecting beyond the mass of particles to provide a point of contact with said armature, said hard center being composed of carborundum.
CHARLES FRANK MILLER.
REFERENCES CITED The following references are of record in the ille of this patent:
UNITED STATES PATENTS Number Name Date 724,060 Thomas, Jr Mar. 31, 1903 874,908 Fritts Dec. 24, 1907 928,547 Schureman July 20, 1909 1,005,857 Lindquist Oct. 17, 1911 2,141,890 Weis Dec. 27, 1938 2,356,577 Fuschaldo Aug. 22, 1944 2,427,872 Newman Sept. 23, 1947 OTHER REFERENCES Bergtold, Ser. No. 343,083,`May 18, 1943, (A. P. C. Publication)
US634965A 1945-12-14 1945-12-14 Core for electromagnets Expired - Lifetime US2482860A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US634965A US2482860A (en) 1945-12-14 1945-12-14 Core for electromagnets

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US634965A US2482860A (en) 1945-12-14 1945-12-14 Core for electromagnets

Publications (1)

Publication Number Publication Date
US2482860A true US2482860A (en) 1949-09-27

Family

ID=24545859

Family Applications (1)

Application Number Title Priority Date Filing Date
US634965A Expired - Lifetime US2482860A (en) 1945-12-14 1945-12-14 Core for electromagnets

Country Status (1)

Country Link
US (1) US2482860A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2597476A (en) * 1948-03-24 1952-05-20 Westinghouse Electric Corp Electromagnet
US2677024A (en) * 1951-09-24 1954-04-27 Welch Thomas Ross Relay
US2756371A (en) * 1951-08-10 1956-07-24 Milwankee Gas Specialty Compan Magnet frame and coil assembly for thermoelectric safety devices and mounting therefor
US2860403A (en) * 1953-06-30 1958-11-18 Warner Electric Brake & Clutch Method of making a pole piece unit for magnets
US2915683A (en) * 1954-09-20 1959-12-01 Alexander J Lewus Electromagnetic relays
US3117257A (en) * 1962-02-02 1964-01-07 Anderson Controls Inc Solenoid having a rotatable back stop for the plunger
US3472141A (en) * 1966-12-12 1969-10-14 Pentacon Dresden Veb Photographic camera shutter control
US4166262A (en) * 1976-11-15 1979-08-28 Detroit Coil Company Solenoid
US4833980A (en) * 1987-08-31 1989-05-30 Mannesmann Tally Corporation High efficiency coil posts for print hammer actuators
US20180130586A1 (en) * 2015-07-06 2018-05-10 Trumpf Laser Marking Systems Ag Devices and systems for deflecting a laser beam

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US724060A (en) * 1901-11-25 1903-03-31 Noah Thomas Jr Transforming system.
US874908A (en) * 1886-11-23 1907-12-24 Spencer B Prentiss Apparatus or means for the production, transmission, and distribution of electric currents.
US928547A (en) * 1907-09-20 1909-07-20 J L Schureman Company Electrical starting device.
US1005857A (en) * 1910-02-09 1911-10-17 Otis Elevator Co Alternating-current electromagnet.
US2141890A (en) * 1935-07-26 1938-12-27 Siemens Ag Variable inductance device
US2356577A (en) * 1940-02-12 1944-08-22 Fuscaldo Ottavio Electromagnetic control for injectors of internal-combustion engines
US2427872A (en) * 1943-03-24 1947-09-23 Rca Corp Tapered magnetic core

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US874908A (en) * 1886-11-23 1907-12-24 Spencer B Prentiss Apparatus or means for the production, transmission, and distribution of electric currents.
US724060A (en) * 1901-11-25 1903-03-31 Noah Thomas Jr Transforming system.
US928547A (en) * 1907-09-20 1909-07-20 J L Schureman Company Electrical starting device.
US1005857A (en) * 1910-02-09 1911-10-17 Otis Elevator Co Alternating-current electromagnet.
US2141890A (en) * 1935-07-26 1938-12-27 Siemens Ag Variable inductance device
US2356577A (en) * 1940-02-12 1944-08-22 Fuscaldo Ottavio Electromagnetic control for injectors of internal-combustion engines
US2427872A (en) * 1943-03-24 1947-09-23 Rca Corp Tapered magnetic core

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2597476A (en) * 1948-03-24 1952-05-20 Westinghouse Electric Corp Electromagnet
US2756371A (en) * 1951-08-10 1956-07-24 Milwankee Gas Specialty Compan Magnet frame and coil assembly for thermoelectric safety devices and mounting therefor
US2677024A (en) * 1951-09-24 1954-04-27 Welch Thomas Ross Relay
US2860403A (en) * 1953-06-30 1958-11-18 Warner Electric Brake & Clutch Method of making a pole piece unit for magnets
US2915683A (en) * 1954-09-20 1959-12-01 Alexander J Lewus Electromagnetic relays
US3117257A (en) * 1962-02-02 1964-01-07 Anderson Controls Inc Solenoid having a rotatable back stop for the plunger
US3472141A (en) * 1966-12-12 1969-10-14 Pentacon Dresden Veb Photographic camera shutter control
US4166262A (en) * 1976-11-15 1979-08-28 Detroit Coil Company Solenoid
US4833980A (en) * 1987-08-31 1989-05-30 Mannesmann Tally Corporation High efficiency coil posts for print hammer actuators
US20180130586A1 (en) * 2015-07-06 2018-05-10 Trumpf Laser Marking Systems Ag Devices and systems for deflecting a laser beam

Similar Documents

Publication Publication Date Title
US3460081A (en) Electromagnetic actuator with permanent magnets
US2275880A (en) Magnetic structure
US2482860A (en) Core for electromagnets
US3103603A (en) Alternating current synchronous reciprocating motor unit
US2609464A (en) Relay
US4306207A (en) Self-sustaining solenoid
US9923443B2 (en) Hollow magnetic metal core pulse energy harvesting generator
US3091725A (en) Electro-magnetic device
PL130707B2 (en) Anisotropic permanent magnet and method of making the same
US3805099A (en) Linear actuator
GB747736A (en) Improvements in or relating to devices comprising a circuit of highly-permeable material and a permanent magnet for producing a pre-magnetizing field in said circuit
US2497547A (en) Magnetic switch
US3252018A (en) Superconducting alternator
US1878919A (en) Driving system for loud speakers
US2802078A (en) Magnetic latch bi-stable relay
US2357834A (en) Vibrating converter
US3134867A (en) Multiple-flux electrical reed relay
US2933571A (en) Relay
US2180159A (en) Electromagnetic device
US3500086A (en) Magneto - electric pulse generator especially for igniting gas-operated devices
JPS55156309A (en) Magnetization of annular magnet
US2136337A (en) Electrical apparatus
US2942163A (en) Constant-impedance alternating current relay motor-devices
US3454825A (en) Composite magnet structure
US1630380A (en) Loud-speaker unit