GB682053A - Improvements relating to air-blast switches - Google Patents

Abstract

682,053. Air-blast switches. CZECHOSLOVAK HEAVY ENGINEERING WORKS, NATIONAL CORPORATION, and GROSSE, V. May 14, 1948 [April 21, 1948], No. 11087/51. [Divided out of 681,985, under which a Specification was laid open to inspection, Nov. 16, 1948.] Class 38 (v) An air-blast switch has main interrupting contacts 1, 2 connected in parallel with auxiliary interrupting contacts 3, 4 in series with a resistor (not shown), and an isolator 6, the sequence of operation being that the contacts 1, 2 open first, the opening movement of the isolators is initiated and the contacts 3, 4 are then opened. When compressed air is admitted to the chamber (not shown), surrounding the contacts 1, 2, it acts on a piston 12 to open the contacts 1, 2, an arc-extinguishing blast flowing out of the chamber through the nozzle contact 2. When a desired separation of the contacts 1, 2 has occurred, piston 12 uncovers a port 15 and compressed air is applied to the piston 23 to open the isolator 6. Just before the movable contact of the isolator has separated from its fixed contact, the piston 23 uncovers a port 16 and admits compressed air to the chamber 8 of the auxiliary interrupter to open the contacts 3, 4 and to provide an arc-extinguishing blast through the nozzle contact 3. Springs 9, 10 reclose the contacts 1, 2 and 3, 4 when the blast ceases and the isolator is reclosed when air is supplied through a pipe 41 to the "closing" piston 24. The Specification as open to inspection under Sect. 91, also includes the subject-matter of Specifications 691,168 and 691,169, This subject-matter does not appear in the Specification as accepted.