GB797892A - Flashing or twinkling electric incandescent lamp - Google Patents

Abstract

797,892. Flashing electric lamps. LUMALAMPAN AKTIEBOLAG. May 23, 1955 [June 12, 1954], No. 14826/55. Class 39(2) A flashing lamp in which a length of filament is short-circuited periodically by a bimetal strip is characterized by the filament being supported at its ends and at one or more intermediate points, the bimetal strip being fixed adjacent to and in electrical contact with one point of support and arranged to make electrical contact with another point of support when affected by the heat from the length of filament with which the strip is associated. In one arrangement a filament 5, 6 of inverted V-shape has its apex supported by a resilient wire 9 which has its lower end sealed within a glass bead 7, the two ends of the filament being connected to leading in wires 3, 4 also sealed within the bead 7. A single bimetal strip 10 fixed to the upper end of the wire 9 extends downwardly so that in its inoperative position it bisects the angle between the parts 5, 6 of the filament. When, however, the filament is energized, the bimetal strip is heated and warps, e.g. to the left, where it contacts the inturned end of the leading-in wire 3 and short-circuits the left-hand limb of the filament. In a modification, Figs. 2a and 2b (not shown) two bimetal strips extend downwardly between the limbs of an inverted V-shaped filament from a common support and by making the limbs of different lengths, three different degrees of brightness may be obtained when either or both filaments is, or are, energized. In a further modification, Fig. 3b, a substantially straight filament 6 stretched longitudinally with its ends connected between two leading-in wires 3, 4, is provided with an intermediate support comprising a wire 13 which is supported by the glass bead 7 holding the leading-in wires in position and has its upper portion offset and secured to the filament, the offset end 13a forming a contact for the lower-end of a bimetal strip 14 extending downwardly from an upper connecting point with the offset upper end of the longitudinal leading-in wire 3. The position of the point of connection between the offset portion of the intermediate supporting wire 13 and the filament may be varied so that different lower lengths 6 are obtained. Specification 694,660 is referred to.