GB594563A - Electric discharge tube - Google Patents

Abstract

594,563. Discharge lamps. LUMALAMPAN AKTIEBOLAG. March 9, 1945, No. 5896. Convention date, Feb. 18, 1944. [Class 39 (i)] [Also in Groups XXXV and XXXVII] In an electric discharge lamp, the preheating circuit for an electrode 5 is opened by the action of a bimetallic strip 4 against a contact arm 7 included in the circuit, in response to the heat from the electrode ; the bimetallic strip is not included in the preheating circuit. As shown, the electrode holder 6 is normally connected with the wire 8 for preheating by the resilient arm 7. The bimetal 4 secured to electrode holder 3 disconnects the arm 7 from the wire 8 (Fig. 2c) on being heated by the electrode. Both the bimetal and the contact arm may alternatively be mounted on the same holder 6. The electrode at each end of the lamp may be provided with a relay, the two relays being connected in series. The Specification as open to inspection under Sect. 91 comprises also an arrangement in which the thermal relay is outside the lamp, in which case the heat to operate the bimetal is supplied by an incandescent body which may participate in the light emission from the lamp, connected in series with the discharge path of the lamp. This subject-matter does not appear in the Specification as accepted.