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
  • H01H1/0201—Materials for reed contacts

Definitions

• the contacts members generally at the ends of resilient conductors are jointly present in a closed space filled with a shield gas.
• the conductors consist of magnetic material by which the contact can be opened or closed with the aid of coils or permanent magnets placed outside the envelope.
• This non-metal-containing layer may entirely consist of carbon, graphit, phosphorus, sulphur, silicon or metal oxide and may have a thickness of between 0.001 and atm and the outer layer consists of ruthenium and rhodium.
• the non-metal is present in a finely divided form in a metal having a melting point of less that l500C in a total layer thickness of at least 0.] ,um.
• the relevant layers on the contacts according to this patent application may be provided by cathodic sputtering of the relevant materials, by electrolytic coprecipitation, by vapour deposition or by electrophoresis,
• plane contact erosion can be realized in a simple manner in a contact device in a hermetically closed envelope filled with a shield gas, which device is characterized by the presence on the surface of the moving contacts of separate particles having a size of from 0.01 to pm of a material having a specific resistance of not more than 10 Qcm in a quantity of at least 1 particle per sq.mm while the surface of the contact members consists of metal having a thickness of at least 1 pm and a hardness of at least 100 Vickers.
• the particles in a method of manufacturing the switching device may be formed in a non-adherent manner on the surface of the contact members by effecting at their surface hydrolysis of chlorides which form compounds of the desired kind.
• the size of the particles exceeds 10 am they are pulverized during the initial period by switching the switching device so that after a relatively small number of switching operations the required quantity of particles is formed.
• Reed contacts are coated with a 3 ,um thick molybdenum layer by cathodic sputtering at a voltage of 1,500 V, a current intensity of 1.2 A and subsequently coated with a 0.1 pm thick layer of ruthenium at a voltage of 1,500 V and a current intensity of 0.4 A under an argon pressure of 10 mm Hg. Subsequently carbon particles are provided by immersion in a freon suspension. The reed contacts are subsequently sealed pairwise in a glass envelope and lifetested. This lifetest is effected in an unloaded condition and under the socalled crosspoint load in which cable discharges over 45, 75 and Ohm with cable lengths of 1, 2, 20 and 100 meters are performed under a direct voltage of 50 Volt. The contact coating exhibits in all these experiments a plane erosion and a low resistance of less that mOhm at at least 100 X 10 switching operations in the unloaded condition. The requirement of at least 0.5 3 X 10 switching operations in a loaded condition is easily satisfied.
• Reed contacts are coated in the same manner as in example 1 with a 0.1 pm thick gold layer and subsequently provided with ruthenium particles by immersion in a suspension of ruthenium powder in freon (particle size 0.l 1 am).
• the contacts sealed in an envelope equipped with these materials have properties which are equivalent to those of example 1.
• Reed contacts whose parts to be sealed within the envelope is approximately 7 mm long and 0.5 mm wise and which consist of nickel iron are coated in a cathode sputtering device with a film of gold having a thickness of 0.1 pm.
• the argon pressure during sputtering is 10" mm Hg, the voltage is 1,500 V and the current is 0.5 A.
• a loose layer of carbon particles is provided by immersion in a suspension of carbon particles in freon.
• This cantata: coating has plane erosion and a low resistance in case 0f loaded switching. The results obtained are also equivalent to those with the contacts of example 1.
• a switching device as claimed in claim 1 characterized in that a film having a thickness of 0.01 1.0 pm is present on the hard surface layer and that this layer consists of metal having a specific resistance which is less that 10 Qcm.

Landscapes

• Contacts (AREA)
• Manufacture Of Switches (AREA)
• Switch Cases, Indication, And Locking (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=19818821

Family Applications (1)

Country Status (11)

Cited By (1)

Families Citing this family (4)

Citations (3)

• 1973
  • 1973-05-09 NL NL7306444A patent/NL7306444A/xx not_active Application Discontinuation
• 1974
  • 1974-04-20 DE DE2419043A patent/DE2419043C3/de not_active Expired
  • 1974-05-03 US US466714A patent/US3916132A/en not_active Expired - Lifetime
  • 1974-05-06 CH CH615374A patent/CH600524A5/xx not_active IP Right Cessation
  • 1974-05-06 GB GB1977374A patent/GB1451124A/en not_active Expired
  • 1974-05-06 SE SE7405993A patent/SE393215B/xx unknown
  • 1974-05-06 IT IT22325/74A patent/IT1010436B/it active
  • 1974-05-07 BE BE144033A patent/BE814677A/fr not_active IP Right Cessation
  • 1974-05-07 ES ES426027A patent/ES426027A1/es not_active Expired
  • 1974-05-08 JP JP49050349A patent/JPS5015065A/ja active Pending
  • 1974-05-08 FR FR7415875A patent/FR2229127B1/fr not_active Expired
• 1981
  • 1981-07-08 JP JP56105747A patent/JPS5763713A/ja active Pending

Patent Citations (3)

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