Elektrischer Schalter fuer ein diagnostisches Tascheninstrument

1,101,367. Surgical optical instruments. WELCH ALLYN, Inc. 5 Sept., 1966 [28 Sept., 1964], No. 39606/66. Heading ASR. [Also in Divisions F4 and G2] A diagnostic instrument, such as an otoscope, is fitted with a housing 14 containing a battery 15 and carrying a tubular metal socket 23 in which is an electric lamp bulb 21, the base contact of which engages one pole of the battery, the other contact of which is connected by a metal strip 33 to a spring plate carrying a hemispherical contact, the housing carrying a ring 30 of insulating material having a hole in which is mounted a brush in contact with the socket 23 so that turning the ring brings the contact into register with the hole to complete the circuit. The ring has a second hole closed by a piece of coloured insulating material to hold the ring in engagement with the contact to maintain the circuit open. The instrument has a head 11 with a viewing lens 16 at one end and an opening 18 at the other, a bundle of light conducting fibres 20 leading from the lamp 21 to the opening 18.