Patent GB-480377-A (GB)
Title: Improvements in or relating to electric switches having gas blast quenching of the arc
IPC: H01H33/12
Filed: 1936-10-23
Abstract: 480,377. Gas-blast switches. STRAUSS, (nÚe RUPPEL), F. Oct. 23, 1936, No. 28884. [A Specification was laid open to inspection under Sect. 91 of the Acts, April 24, 1937.] [Class 38 (v)] A switch comprises arcing-contacts between which only a light touching contact is adapted to be established, and the point of contact of said contacts is disposed in a chamber from the walls of which gases and vapours are generated by the arc, the chamber being closed at one end and open at the other to provide egress for the movable contact and the generated arc-quenching gases. Contacts normally carrying current in the " on " position of the switch are disposed outside the chamber and in parallel to the arcing-contacts. Fig. 1 shows a form in which the quenching contacts are separated in a tube 5, the inside at least of which comprises an insulating substance giving off quenching gas under arcaction such as amino plastics with fillings, an insulating adjustable filler rod 6 being provided and being preferably gas-evolving. The movable quenching contact 2 is tubular and co-operates with a fixed ring 1, whereas the movable working contact 4 is a split cylinder attached to carrier 7 and pressed by spring ring 9 against the fixed working contact 3. The are is drawn in the annular space between 5, 6 and the gases flow out of openings 10 in carrier 7. In a modification, Fig. 2 (not shown), the quenching contact 2 is movable relatively to carrier 7 against the action of a spring, so that additional movement can rapidly take place when excessive pressures occur on breaking large currents. In Fig. 3, the filler 6 is attached to the movable rod contact 2 and it and the working contacts 3, 4 are operated by a linkage 17 which subsequently opens a series disconnecting switch 16. The two halves of a cooling device- 21 for the gases surround the linkage on both sides, and may conduct current from ring 24 to pivot 23 of the switch 16. In Fig. 4 (not shown), the rod contact 2 and attached filler are fixed, and the tube 5 and contacts 1, 3 lowerable to open circuit. The Specification as open to inspection under Sect. 91 contained also the following. In a compressed-gas blast switch employing a nozzle for contact 1, the co-operating contact 2 is restrained by a pawl while the operating member, in opening 4, is stressing a spring. After a certain travel, the operating member trips the pawl, so permitting the spring to extract the movable contact from the nozzle contact and allowing the blast to flow, Fig. 5 (Cancelled, not shown). In Fig. 6 (Cancelled) the blast admitted at 37 is adapted when the pawl 35 is deflected, to raise a piston 38, carrying contact 2, so as to uncover exhaust openings 41, a spring 40 restoring the piston and contact. Deflection of the pawl 35 is produced by a spring (not shown) when the projection 39 on arm 16 moves past it. The working contact 4 is integral with arm 16 which, by means of contact 22 (which can also be without contact-pressure), maintains the circuit until after extinction of the arc between 1, 2. This subject-matter does not appear in the Specification as accepted.