US3348012A - Contact structure for an electric vacuum switch - Google Patents

Contact structure for an electric vacuum switch Download PDF

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Publication number
US3348012A
US3348012A US527124A US52712466A US3348012A US 3348012 A US3348012 A US 3348012A US 527124 A US527124 A US 527124A US 52712466 A US52712466 A US 52712466A US 3348012 A US3348012 A US 3348012A
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US
United States
Prior art keywords
contact
annular
ridge
contact surface
vacuum switch
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
US527124A
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English (en)
Inventor
Knapton Arthur George
Reece Michael Peter
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.)
Associated Electrical Industries Ltd
Original Assignee
Associated Electrical Industries 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.)
Filing date
Publication date
Application filed by Associated Electrical Industries Ltd filed Critical Associated Electrical Industries Ltd
Application granted granted Critical
Publication of US3348012A publication Critical patent/US3348012A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/60—Switches wherein the means for extinguishing or preventing the arc do not include separate means for obtaining or increasing flow of arc-extinguishing fluid
    • H01H33/66—Vacuum switches
    • H01H33/664—Contacts; Arc-extinguishing means, e.g. arcing rings
    • H01H33/6642—Contacts; Arc-extinguishing means, e.g. arcing rings having cup-shaped contacts, the cylindrical wall of which being provided with inclined slits to form a coil
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00—Contacts
    • H01H1/02—Contacts characterised by the material thereof
    • H01H1/0203—Contacts characterised by the material thereof specially adapted for vacuum switches

Definitions

  • a vacuum switch contact having an annular ridge which provides the contact surface and is formed with inclined slots which extend into the ridge from the contact surface and divide that surface into discrete contact areas.
  • the ridge is provided with an internal or an external resilient skeleton which permits relative displacement of the contact areas so that they can accommodate irregularities in a surface against which the contact surface is pressed.
  • This invention relates to switch contacts of, or suitable for use in, electrical vacuum switches suitable for interrupting large currents.
  • the current normally flows in series through a pair of contacts located in a chamber which is either evacuated or contains a gas at a very low pressure, the two contacts being so arranged that they may be moved apart to interrupt the flow of current.
  • the surfaces of the two contacts through which the current flows should be in firm contact with each other over substantially the whole of their areas. However, this firm contact tends to be impeded by any Slight irregularities which may be present on the contacting surfaces.
  • An object of this invention is to provide a vacuum switch contact which to some degree reduces the above disadvantage.
  • a contact member suitable for use in a vacuum switch has an annular ridge which provides an annular contact surface and is formed with a plurality of substantially radial slots extending into the ridge from the annular contact surface to divide the annular contact surface into discrete contact areas, the slots being inclined to the longitudinal axis of the ridge and that part of the contact member forming the annular ridge having resilience permitting relative displacement of the contact areas to accommodate surface irregularities in a cooperating contact surface against which the contact surface is pressed.
  • a vacuum switch comprises an evacuable envelope, and a pair of relatively movable contact members disposed inside the envelope and having adjacent contact surfaces, one of the contact members having an annular ridge which provides an annular contact surface and which is formed with a plurality of substantially radial slots extending into the ridge from the annular contact surface to divide the contact surface into discrete contact areas, the slots being inclined to the longitudinal axis of the ridge and that part of the one contact member forming its annular ridge having resilience permitting relative displacement of the con- ICC tact areas to accommodate surface irregularities in the contact surface of the other contact member when the contact surfaces of the two contact members are pressed together.
  • both contact members of the pair are contact members in accordance with the invention in which case the slots in the two contact members are inclined in opposite directions.
  • FIGURE 1 is a perspective view of a vacuum switch contact in accordance with the invention.
  • FIGURE 2 is a fragmentary side view of an alternative form of the switch contact shown in FIGURE 1;
  • FIGURE 3 is a plan view of another form of the switch contact shown in FIGURE 1;
  • FIGURE 4 is a side view, partly in section, of a vacuum switch including a contact assembly embodying the in vention.
  • a contact member 1 suitable for use in an electrical vacuum switch has an annular contact surface 3 divided into a number of discrete contact areas such as 3A, 3B and 3C by a plurality of sub-' stantially radial slots 5 which extend into the member from the contact surface 3.
  • the slots 5 are inclined at an angle to the surface 3, and effectively divide the annulus into a plurality of contact elements 7 each of which provides one or more contact area(s).
  • the material from which the contact member 1 is formed has a resilience such that when the contact surface 3 is pressed firmly against a co-operating contact having minor surface itregularities, it permits relative displacement of the contact areas such as 3A, 3B and 3C so that the contact surface 3 tends to conform to the shape of the irregular surface.
  • the presence of a high spot on either the surface 3 or the corresponding surface of the co-operating contact member will not prevent firm contact between the majority of the contact areas and the surface of the co-operating contact.
  • the resilient material from which the contact member is formed can be a suitable alloy of copper and one or more metals which has a degree of resilience after baking at a temperature of 700 degrees centigrade for 12 hours.
  • a suitable alloy can conveniently consist of copper and one or more of the following metals in suitable proportions, iron, zirconium, titanium and chromium.
  • the required resilience may be provided by -a contact member 1 constructed as shown in FIGURE 2 and comprising a resilient skeleton 9 formed from a resilient ring 11 having a plurality of resilient fingers 13 secured thereto and embedded in a suitable metal casting.
  • the skeleton 9 can be of steel or other metal which does not anneal appreciably at 700 degrees centigrade, and the metal forming the casting can be copper.
  • the slots 5 are cut in the portions of the casting between the fingers 13.
  • the skeleton 9 can conveniently be formed from perforated strip to ensure a firm bond with the copper of the casting and the dimensions of the fingers 13 can be chosen to give the desired degree of resilience.
  • the resilience may be provided by suitable metal fibres or wires embedded in the copper casting.
  • Such wires or fibres can be of stainless steel, nickel-iron alloy, molybdenum, or tungsten, orientated in either a predetermined manner or a random manner. If the fibres are orientated in a random manner they should be of a substantially gas free metal to avoid any deleterious effects during out-gassing of the vacuum switch chamber, as some of the fibres are likely to be exposed when the slots 5 are cut.
  • the wires or fibres are orientated in a predetermined manner they are arranged to extend lengthwise along the contact elements 7 substantially parallel to the slots 5.
  • wires typically such wires would be about 0.5 millimetre in diameter and 'would be spaced about 1 millimetre apart.
  • wires are of a suitable refractory metal such as molybdenum or tungsten the ends of the wires can be arranged to extend to the contact surface '3.
  • the resilience is provided by inner and outer cylindrical shells 15 and 17 of a refractory metal such as molybdenum between which the copper body is cast, so that after the slots have been cut these shells act to stiffen the contact elements 7.
  • the vacuum switch comprises a chamber having a body 19 of electrically insulating material and two end plates 21 and 23 of electrically conductive material.
  • An aperture 25 is formed in end plate 21 and a movable conductor 27 extends through this aperture.
  • a bellows member 29 extends between the conductor 27 and the end plate 21 so as to seal the aperture 25 but permit movement of the conductor 27 relative to the end plate 21.
  • a fixed conductor 31 extends through the other end plate 23.
  • the adjacent ends of the conductors 27 and 31 are provided with contact members 1 having annular contact surfaces 3 divided into a number of discrete contact areas by slots 5 as previously described.
  • the slots 5 in the two contact members 1 are inclined in opposite directions.
  • the chamber is evacuated to a very low pressure of the order of mm. of Hg or less.
  • the resilience of the contact elements 7 perm-its relative displacement of the contact areas so that they can accommodate surface irregularities in the contact surface 3 of either contact member 1 so that each pair of opposed discrete contact areas makes contact with one another at at least one point.
  • a contact member suitable for use in a vacuum switch comprising:
  • a contact member as claimed in claim 1, wherein the resilient skeleton comprises an external skeleton formed by inner and outer cylindrical shells of a refractory metal having a cast copper body between them, the slots extending radially through the shells.
  • a contact member as claimed in claim 1, wherein the skeleton comprises an internal skeleton having a plurality of resilient fingers embedded in a suitable metal casting with the fingers extending into the ridge between the slots.
  • a vacuum switch comprising:
  • the resilient skeleton comprises an external skeleton formed by inner and outer cylindrical shells of a refractory metal having a cast copper body between them, the slots extending radially through the shells.
  • a vacuum switch as claimed in claim 7, wherein the skeleton comprises an internal skeleton having a plurality of resilient fingers embedded in a suitable metal casting with the fingers extending into the ridge between the slots.
  • a vacuum switch comprising:

Landscapes

  • Manufacture Of Switches (AREA)
  • High-Tension Arc-Extinguishing Switches Without Spraying Means (AREA)
  • Contacts (AREA)
US527124A 1965-02-16 1966-02-14 Contact structure for an electric vacuum switch Expired - Lifetime US3348012A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB6674/65A GB1100259A (en) 1965-02-16 1965-02-16 Improvements relating to vacuum switch contacts

Publications (1)

Publication Number Publication Date
US3348012A true US3348012A (en) 1967-10-17

Family

ID=9818750

Family Applications (1)

Application Number Title Priority Date Filing Date
US527124A Expired - Lifetime US3348012A (en) 1965-02-16 1966-02-14 Contact structure for an electric vacuum switch

Country Status (7)

Country Link
US (1) US3348012A (es)
BE (1) BE676601A (es)
CH (1) CH468708A (es)
DE (1) DE1254217B (es)
GB (1) GB1100259A (es)
NL (1) NL6601951A (es)
SE (1) SE324396B (es)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3150168A1 (de) * 1981-12-18 1983-06-30 Sachsenwerk, Licht- und Kraft-AG, 8000 München "elektrischer vakuumschalter"
US5597992A (en) * 1994-12-09 1997-01-28 Cooper Industries, Inc. Current interchange for vacuum capacitor switch

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3232708A1 (de) * 1982-08-31 1984-03-01 Siemens AG, 1000 Berlin und 8000 München Vakuumschaltroehre mit schraubenlinienfoermiger strombahn
US4553003A (en) * 1984-03-30 1985-11-12 Westinghouse Electric Corp. Cup type vacuum interrupter contact
DE3828556C1 (en) * 1988-08-23 1990-03-15 Sachsenwerk Ag, 8400 Regensburg, De Contact arrangement for a vacuum switch

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2900476A (en) * 1956-04-17 1959-08-18 Era Patents Ltd Electrical switching apparatus
US3014104A (en) * 1958-12-12 1961-12-19 Gen Electric Electrical contacts
US3089936A (en) * 1960-02-23 1963-05-14 Gen Electric Contact structure for an electric circuit interrupter
US3254189A (en) * 1961-05-15 1966-05-31 Westinghouse Electric Corp Electrical contact members having a plurality of refractory metal fibers embedded therein

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL244627A (es) * 1958-07-24
GB1020914A (en) * 1961-11-10 1966-02-23 Gen Electric Improvements in vacuum circuit interrupter
DE1251406B (es) * 1962-01-24
NL299341A (es) * 1964-03-11

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2900476A (en) * 1956-04-17 1959-08-18 Era Patents Ltd Electrical switching apparatus
US3014104A (en) * 1958-12-12 1961-12-19 Gen Electric Electrical contacts
US3089936A (en) * 1960-02-23 1963-05-14 Gen Electric Contact structure for an electric circuit interrupter
US3254189A (en) * 1961-05-15 1966-05-31 Westinghouse Electric Corp Electrical contact members having a plurality of refractory metal fibers embedded therein

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3150168A1 (de) * 1981-12-18 1983-06-30 Sachsenwerk, Licht- und Kraft-AG, 8000 München "elektrischer vakuumschalter"
US5597992A (en) * 1994-12-09 1997-01-28 Cooper Industries, Inc. Current interchange for vacuum capacitor switch

Also Published As

Publication number Publication date
BE676601A (es) 1966-07-18
GB1100259A (en) 1968-01-24
CH468708A (de) 1969-02-15
SE324396B (es) 1970-06-01
NL6601951A (es) 1966-08-17
DE1254217B (de) 1967-11-16

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