GB364942A - Improvements in or relating to electric lamp holders - Google Patents

Abstract

364,942. Electric lamp holders. IDE,. G. H. and BENTLEY, H. L., Magnet Works, Landor Street, Birmingham. March 20, 1931, No. 8560. [Class 39 (ii).] An electric lamp holder adapted for seriesconnection is provided with a short-circuiting: arm d, Figs. 1 and 4, adapted normally to span. two contact members c<1>, c<2> connected to the spring plungers c which engage the lamp contacts, and a slidable pin f, Fig. 3, which operates to lift the short-circuiting arm when a lamp is inserted into the holder. The short-circuiting arm d is L-shaped and is located within a. correspondingly shaped recess a<1> in the porcelain body a of the holder, the short limb d<1> of the arm being held by a fastening screw e and pressed downwardly by a spring e<1>. The ends. of the other limb d<2> of the contact arm normally make contact with heads c<1>, c<2> of two screws, and the centre portion of the limb d<2> is cranked upwardly at d<3> to receive an insulating roller f<2> on the upper part f<1> of an L-shaped slidable pin f. The lower end of the pin f does not protrude as far as the spring plungers c. Upon the insertion of a lamp into the socket the pin f is moved. inwardly to displace the contact arm d from the contacts c<1>, c<2>, so that current flows through the lamp filament by way of the contacts c. The device may be applied to a lamp holder provided with a switch of either the turnbutton or pushbar type, for example as described in Specification 313,356, [Class 38 (v), Electric switches &c.].