Patent GB-191303882-A (GB)
Title: Method and Apparatus for Suppressing the Interruption Arc on Electric Switches.
Inventor: BURSTYN WALTHER
IPC: H01H9/54
Filed: 1913-02-14
Granted: 1914-02-12
Abstract: 3882. Burstyn, W. Feb. 14. Sparking, preventing.-The poles of a switch are connected to an auxiliary circuit containing a source of electric shocks, such as a charged condenser or an alternator, the shock being timed to occur at or about the instant of opening the switch and counter to the spark-producing electromotive force, so as to suppress or quench the arc. In the case of a charged condenser, a discharge is produced at the proper moment by closing an auxiliary switch. The shock may be applied after the arc has been formed provided it has not been drawn to a length greater than ¢ mm. to 1¢ mm. The spark contacts may be of silver, copper, platinum, platinoiridium, or tungsten, and may be artificially cooled or placed in an atmosphere of hydrogen. Fig. 1 shows one arrangement. A main switch s in a circuit p containing electrical apparatus a is connected to an auxiliary circuit containing a condenser c, an inductance i, and an auxiliary switch r. By means of a connexion through a resistance w, the condenser is charged as soon as the switch s is closed, the switch r remaining open. Just before or at the moment when the switch s is to be opened, the switch r is closed and the condenser is discharged across the poles of the switch s. Fig. 2 shows a modification in which the charged condenser d is in a separate circuit fed by a battery and the discharge produced by closing the switch r is transmitted to the poles of the switch s through a transformer t. Fig. 5 shows an arrangement in which an alternator e, driven continually or switched in at the required, moment furnishes arc-quenching current for a number of separate switches s. Further modifications of the charged condenser arrangement have the following additional features: -Placing a battery in the charging connexion through the resistance w, Fig. 1, in order to raise the potential of the condenser; omitting this connexion and charging through the switch r; substituting a twoposition switch for the two separate switches s, r; arranging that the discharge is not produced until the arc has been drawn to a certain length; placing an unprotected switch of larger current capacity in series or parallel with the protected switch; adapting the arrangement to a double-pole switch so that a single charged condenser is applied to both poles; and adding aluminium cells, mercury-vapour valves, uncharged condensers, inductance coils, and resistances to the above-described arrangements. Figs. 9, 12, and 14 indicate the construction of different types of switches embodying the invention. The construction shown in Fig. 9 comprises pivoted main switch contact-members s, n formed with arcing-horns, and an auxiliary switch constituted by a pivoted spring finger having two contacts v, x. That shown in Fig. 12 comprises a larger capacity switch h in series with the sparking-switch s, each of the switches s, r being constituted by a set of paralleldisposed contacts mounted on a push-rod k. Fig. 14 shows a rotary interrupter in which the brush 7 corresponds to the switch s shown in Fig. 1, and the brush 2 to the switch r. The brushes wipe a metal disk having an insulating- segment and are adjusted in position until the apparatus works sparklessly. A heavier brush 3 is employed in parallel. The invention may be applied also to Morse keys, motor controllers, dynamo collectors, automatic starters, Tyrill regulators, maximum cut-outs, current limiters, advertising-lamp switches, relays, and oscillatory or rotary converter switches.