GB609211A - Improvements in and relating to electric lamp bases and holders - Google Patents

Abstract

609,211. Lamp caps and holders. BRITISH THOMSON-HOUSTON CO., Ltd. April 10, 1945, No. 8856. Convention date, April 12, 1944. [Class 38 (i)] A lamp base 23, Fig. 1, for a photoflash bulb of the type described in Specification 586,129, comprises a web portion 37 and a square rim portion 39 surrounding a circular cavity having an annular groove 41 for the reception of the neck 22 of a lamp bulb 21. The lead-in wires 24, 25 for the bulb pass through apertures 26, 27 in the web portion, their outer ends being sealed into further apertures 28, 29 so as to form two contacts 30, 31, the said apertures being so positioned that the said contacts are disposed eccentrically on the base. Two arcuate support-engaging flanges 43 are formed on opposite sides of the rim 39. Fig. 4 shows a holder for the base comprising a plate 56 having an aperture 57 shaped for the passage therethrough of the base, the latter then being rotated through 90 degrees so that the flanges 43 engage the under surface of the plate and the contacts 30, 31 engage leaf-spring contacts 58, 59 secured to the plate and having aligned grooves 60, 61 respectively, to prevent further rotation of the base. This holder may be modified, Figs. 6 and 7, (not shown) by the addition of two straight wire spring members disposed in slots along the straight sides of the aperture in the plate and projecting slightly therefrom so that subsequent to the straight forward insertion of the base, they clip-over the straight sides thereof. A further modification, Fig. 8, for a plurality of lamps, comprises a spring strip 72 having its edges 73, 74 bent back to form a slot for the reception of the square portion of the base when the latter is inserted through an aperture 78 in the central portion 75 of the strip. The base is then moved longitudinally of the strip, until the flanges 43 spring into a cavity 77. Figs. 10-12 (not shown) illustrate a similar modification in which the bent over edges of the strip have a square depression with which the square portion of the base registers after insertion through an aperture in the face of the strip and subsequent rotation. In further modifications of the base, the flanges 43 may be coplanar with the web portion 37 or the bottom of the base may be circular, the top in this case having two straight parallel surfaces for indexing. The Specification as open to inspection under Sect. 91 also shows a holder for the base. Fig. 4 (Cancelled), which is also disclosed in Specification 586,129, comprising circularlydisposed resilient spring fingers 44 having bevelled ridges 47 which snap over the base flanges 43 and retain the contacts 30, 31 in contact with a central, spring-loaded stud contact 45 and a helical spring contact 46, respectively. This subject-matter does not appear in the Specification as accepted.