Patent GB-677789-A (GB)
Title: Improvements in or relating to electric pocket lamps
IPC: F21L4/00
Filed: 1949-09-02
Abstract: 677,789. Electric battery lamps. SCHNEIDER, E. Sept. 2, 1949 [Sept. 21, 1948], No. 22824/49. Class 39(ii) The bulb of an electric battery lamp is mounted within a screw-threaded metal socket 6 in a cylindrical pot-like member 4 of insulating material which is rotatable axially in a cup-shaped seating 3, Fig. 1, for switching purposes, the bulb socket being formed with an extending contact tongue which is bent around the edge of the base of the cylindrical member 4 and lies within a longitudinal groove on the exterior, so that when the member 4 is rotated into the requisite position the contact tongue is engaged by a spring-pressed stud 12 at the end of a conducting-strip 13 which completes the lamp circuit. Two or more such grooves may be provided, each containing a contact tongue connected to a tapping on a wire resistance wound in a groove around the rotatable cylinder, whereby the light may be dimmed progressively. The conducting strip 13, which partly encircles the cup 3, is mounted on the casing by a rivet through an offset central portion of the strip, and the free end of the strip is arranged to abut against a vertical contact spring 14 of the battery. 'The other contact spring or terminal 16 abuts against the resilient offset end of a contact strip 15 which has a vertical portion provided with an aperture to fit over an axial pin 10 secured in the bottom of the cup 3 and forming the central contact of the bulb socket, the strip 15 and the pin 10 being held in electrical connection by a split-ring around the pin. A part of the contact strip 15 is located between a pair of outward projections 17 on the bottom surface of the cup 3, which serve to hold it against rotary movement. Projections or lugs 18 on the inside wall of the casing maintain the battery in position. The battery casing may be in two separable parts, both made of insulating material and comprising a front part 1 and rear part 2, fastened together at their upper ends by means of a pair of lugs 19, Fig. 2, projecting outwardly from the front part into the rear part, the lugs 19 and adjacent sides of the rear part 2 being provided with registering apertures to receive securing-pins therethrough. In the example the securing-pins are provided by the inturned ends of a wire carrying-handle 20. At their lower ends the casing parts may be secured together by a hinge or, as shown, by a pin 22 on one part engaging within an ear 23 projecting from the other part. Fig. 6 shows a modification wherein the part 24 of a two-part casing 24, 25 has a vertical cup 26 formed in its upper end to receive a rotary pot-like switching-member and bulb holder 4 provided with an axial contact pin 10, so that when the two casing parts are placed together an aperture in a lug 32 on the part 25 is positioned to receive the lower end of the contact pin which thus assists in holding the parts together. At the lower end of the casing an ear or loop 23 formed at the centre of a two-part compression spring 29 secured in the part 24 engages a button 22 mounted in the part 25. The coupling between the axial contact pin and one terminal of the battery is provided by a sheet metal device comprising an annular potrion 29a, Fig. 8, supporting a spring loop 30 into which the contact pin is pressed, while a bent U-shaped tongue 29a<SP>1</SP> is pushed upon an insulating supporting pillar 27 integral with the casing, in a position to bear upon one terminal of the battery. A similar supporting pillar receives the bent offset end of a metal strip 31 which connects the other battery terminal to the contact 12 co-operating with switch contacts located within diametrically opposite depressions 11b in the rotary switch member 4. Depressions 11a at 90 degrees to the depressions 11b, and without contact members therein, provide " off " positions into which contact 12 clicks.