US2717296A - Electrical switch contacts - Google Patents

Electrical switch contacts Download PDF

Info

Publication number
US2717296A
US2717296A US379844A US37984453A US2717296A US 2717296 A US2717296 A US 2717296A US 379844 A US379844 A US 379844A US 37984453 A US37984453 A US 37984453A US 2717296 A US2717296 A US 2717296A
Authority
US
United States
Prior art keywords
contact
contacts
switch
copper
oxide
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
US379844A
Other languages
English (en)
Inventor
Robert T Foley
Orin P Mccarty
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.)
General Electric Co
Original Assignee
General Electric 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 General Electric Co filed Critical General Electric Co
Priority to US379844A priority Critical patent/US2717296A/en
Priority to JP1973954A priority patent/JPS318220B1/ja
Application granted granted Critical
Publication of US2717296A publication Critical patent/US2717296A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00—Contacts
    • H01H1/02—Contacts characterised by the material thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00—Contacts
    • H01H1/12—Contacts characterised by the manner in which co-operating contacts engage
    • H01H1/36—Contacts characterised by the manner in which co-operating contacts engage by sliding
    • H01H1/365—Bridging contacts
    • 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
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/26—Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension

Definitions

  • This invention relates to electric switch contacts and more particularly to electric switch contacts which operate with a strong applied pressure forcing them tgether. Such contacts are used in tap changing switches .for changing the taps of a transformer. When used in an oil-filled transformer the switch is usually mounted below the surface of the insulating and cooling liquid with which the tank is substantially lled.
  • a typical tap changing switch of the nonarcing duty tap changer type is described in Patent 2,255,501-Blume. While the present switch may be incorporated in a transformer of a type described in the Blume patent it may also be used in certain inert atmospheres as will be more fully described hereinafter.
  • lt is an object of the present invention to provide non-galling contact surfaces which are easily produced.
  • lt is another object of the invention to improve the operation of tap changing switches in which the contact members are normally required slidably to engage one another at pressures of from to 75 pounds.
  • the present invention is based on the discovery that ordinary copper contacts will not gall from sliding contact provided a very thin coating of copper oxide is applied to the contacting surfaces.
  • the invention is directed to an electrical contact comprising a conducting base, and a layer of copper oxide 0.0020.008 mil in thickness overlying the base, the layer of copper oxide serving as a contacting surface.
  • Fig. l of the drawing is a broken perspective View partly' in section of a load ratio adjuster switch
  • Fig. 2 is a side elevation view partly in section of the switch shown in Fig. l
  • Fig. 3 is an enlarged sectional view of a single set of switch contacts.
  • a tap changer or load ratio adjuster switch utilized to change the taps 2,717,296 Patented Sept. 6, 1955 of a transformer (not shown).
  • These switches which normally operate immersed in oil, have a center support post 10 terminating in a stationary circular contact plate 11.
  • a rotatable crank or selector shaft 12 Coaxial with the support post 10 is a rotatable crank or selector shaft 12 on which is mounted a crank arm 13 terminating at its outer end in a pair over-and-under radial slots 14 and 14a, respectively, which maintain a pair of spaced Contact supports 15 in a radial position.
  • the contact supports 15 serve as bases for mounting a pair of clamping contacts 16 at their inner end and clamping contacts 17 at their outer end.
  • the inner clamping contacts 16 are in contact with the contact plate 11 and the outer clamping contacts 17 make selective Contact with one of a plurality of stationary contact terminals 18.
  • Clamping pressure by the contacts 16 against the contact plate 11 and contacts 17 against a particular one of the terminals 18 is maintained by a spiral compression biasing spring 19 mounted upon a bolt Z1 extending in free movement through the contact supports 15.
  • the spring 19, which desirably exerts a pressure of ten pounds or more against the Contact supports 15, works against the head of the bolt 21 and a washer 22 maintained on the opposite end of the bolt 21 by a Cotter pin 23.
  • Figs. l and 2 the heavy shading of the contact surface indicates a coating of copper oxide. All contacting surfaces are provided with such coatings. These coatings are shown more clearly in Fig. 3 though their thickness has been greatly exaggerated for purposes 0f clarity of illustration. Also shown in Fig. 3 is an underlying layer of copper over a base metal. lf the base metal is composed of copper, as is normally the case, there will be no separate copper layer as shown in Fig. 3. However, the base metal may be a less expensive metal than copper in which case it is necessary to coat it with copper before applying the contacting coating of copper oxide.
  • the contacts of this invention may be used in inert media such as oil or atmospheres consisting of nitrogen or the rare gases. Such media provide surrounding environments which are neither oxidizing nor reducing to copper. Performance is also satisfactory where the contacts are submerged in a dielectric oil and exposed to an inert atmosphere periodically.
  • inert media such as oil or atmospheres consisting of nitrogen or the rare gases.
  • An electrical contact member comprising a conducting base, and a layer of copper oxide 0002-0008 mil in thickness overlying said base, said layer of copper oxide serving as a contacting surface.
  • switch contacts comprising a conducting base, and a layer of copper oxide 0002-0008 mil in thickness overlying said base, saidlayers of copper oxide serving as the contacting surfaces of said switch contacts.
  • An oil immersed switch comprising co-operating switch contacts adapted to slidably engage one an0ther at pressures of 10 to 75 pounds, the surfaces of said contacts which are engaged by one another having thereon a coating of copper oxide having a thickness of from 0002-0008 mil.
  • a nonarcing duty tap changer switch for use in an inert medium comprising, in combination, a plurality of stationary Contact members symmetrically distributed around a common axis, and a movable con tact member for selective slidable contact with stationary contact members at contact pressures of from l0 to 75 pounds, the contact surfaces of said stationary contact members and said movable Contact member having thereon thin surface coatings of copper oxide o a thickness of from 0002-0008 mil.

Landscapes

  • Contacts (AREA)
US379844A 1953-09-14 1953-09-14 Electrical switch contacts Expired - Lifetime US2717296A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US379844A US2717296A (en) 1953-09-14 1953-09-14 Electrical switch contacts
JP1973954A JPS318220B1 (xx) 1953-09-14 1954-09-14

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US379844A US2717296A (en) 1953-09-14 1953-09-14 Electrical switch contacts

Publications (1)

Publication Number Publication Date
US2717296A true US2717296A (en) 1955-09-06

Family

ID=23498949

Family Applications (1)

Application Number Title Priority Date Filing Date
US379844A Expired - Lifetime US2717296A (en) 1953-09-14 1953-09-14 Electrical switch contacts

Country Status (2)

Country Link
US (1) US2717296A (xx)
JP (1) JPS318220B1 (xx)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3040150A (en) * 1958-09-05 1962-06-19 Hamilton Watch Co Watch contact post
US3092703A (en) * 1960-07-07 1963-06-04 United Carr Fastener Corp Electrical switch assembly
US3180961A (en) * 1962-06-13 1965-04-27 Cutler Hammer Inc Electrical contact with mating surface area having an integral frusto-conical nib thereon
US3192351A (en) * 1961-05-08 1965-06-29 Fansteel Metallurgical Corp Electrical contact disc
US3302270A (en) * 1962-11-09 1967-02-07 Photocircuits Corp Method of wear-resistant coating a commutator contact surface
US3742170A (en) * 1971-09-30 1973-06-26 Westinghouse Electric Corp Loud tap changer by-pass switch contact assembly and material composition thereof
US3824355A (en) * 1972-06-27 1974-07-16 Asea Ab De-energized tap changer for transformers with polyphase sliding contact assembly
US5523535A (en) * 1992-07-09 1996-06-04 Asea Brown Boveri Ab On-load tap changer
US9824832B2 (en) 2015-05-27 2017-11-21 Abb Schweiz Ag Contact unit for a tap changer and a tap selector comprising the contact unit

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2255501A (en) * 1939-12-12 1941-09-09 Gen Electric Electric switch
US2282249A (en) * 1939-03-21 1942-05-05 Westinghouse Electric & Mfg Co Centrifugal device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2282249A (en) * 1939-03-21 1942-05-05 Westinghouse Electric & Mfg Co Centrifugal device
US2255501A (en) * 1939-12-12 1941-09-09 Gen Electric Electric switch

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3040150A (en) * 1958-09-05 1962-06-19 Hamilton Watch Co Watch contact post
US3092703A (en) * 1960-07-07 1963-06-04 United Carr Fastener Corp Electrical switch assembly
US3192351A (en) * 1961-05-08 1965-06-29 Fansteel Metallurgical Corp Electrical contact disc
US3180961A (en) * 1962-06-13 1965-04-27 Cutler Hammer Inc Electrical contact with mating surface area having an integral frusto-conical nib thereon
US3302270A (en) * 1962-11-09 1967-02-07 Photocircuits Corp Method of wear-resistant coating a commutator contact surface
US3742170A (en) * 1971-09-30 1973-06-26 Westinghouse Electric Corp Loud tap changer by-pass switch contact assembly and material composition thereof
US3824355A (en) * 1972-06-27 1974-07-16 Asea Ab De-energized tap changer for transformers with polyphase sliding contact assembly
US5523535A (en) * 1992-07-09 1996-06-04 Asea Brown Boveri Ab On-load tap changer
US9824832B2 (en) 2015-05-27 2017-11-21 Abb Schweiz Ag Contact unit for a tap changer and a tap selector comprising the contact unit

Also Published As

Publication number Publication date
JPS318220B1 (xx) 1956-09-22

Similar Documents

Publication Publication Date Title
US2717296A (en) Electrical switch contacts
US4064381A (en) Pushbutton switch assembly having floating type bridging contact and lost motion actuator
US2611062A (en) Switch
US2417967A (en) Contact element
US2812406A (en) Electrical contact
US2949592A (en) Adjustable transformer with stabilized contact track
US2469878A (en) Switch contact
US3467800A (en) Reversible cam actuating mechanism for electric switches
GB957644A (en) Improvements in and relating to electric switches
US3715694A (en) Solenoid switch,particularly cryogenic switch
US1770839A (en) Electric contact
US2680174A (en) Electric switch contact
US3214558A (en) Contact arrangement exhibiting reduced material migration
US2647974A (en) Electric switch contact assembly
US2399943A (en) Electrical regulating apparatus
US1833757A (en) Electric contact structure
CN108231439B (zh) 电触头材料
US2331191A (en) Circuit interrupting means
US3360618A (en) Transfer switch for tap-changing transformers convertible for adaptation to a wide range of currents
US3742170A (en) Loud tap changer by-pass switch contact assembly and material composition thereof
US2399944A (en) Electrical regulating apparatus
US2926229A (en) Anti-chatter switching device
US3188589A (en) Electrical commutating surface
US1470758A (en) Rheostat
US3649795A (en) Electrical contacts