Patent GB-509466-A (GB)
Title: Improvements relating to intermittent electric flash lamps
IPC: F21L4/00
Filed: 1938-01-12
Abstract: 509,466. Battery lamps ; electromagnetic interrupters ; road - traffic signs. MULLER GES., C. F. O. Jan. 12, 1938, Nos. 1091 and 1092. Convention dates, Jan. 13, 1937, and April 17, 1937. [Class 39 (ii)] [Also in Groups XVIII and XXXVII] A flashing electric lamp for use as a warning device adapted to be carried by pedestrians or mounted on a vehicle comprises a casing 1 which houses the lamp bulb 16 and an interchangeable box-like unit 25 containing an electromagnetic flashing-switch which acts continuously when supplied with current either from cells 14, 15 located in the casing, or from a separate current source to which the unit may be connected, e.g. the battery of a motor car. In the example, the flashing-unit comprises a pivoted spindle 38 mounted between needlehearings and carrying an armature consisting of two arcuate members 41, 42 of soft iron which co-operate with a, field magnet 44 mounted on the lid of the unit casing 30. The field magnet has a high resistance winding, one end of which is connected to the pole 49 of the battery, the other end being connected to a contact spring 46 forming one of a pair 46, 47 mounted on insulating blocks at opposite corners of the casing 30. The spindle 38 carries a contact pin 45 of non-oxidizing metal such as tungsten which, in the position shown, is held in contact with the contact spring 46 by means of a spiral spring 40 acting in known manner. When the main controlling switch is closed, the field magnet is excited by current flowing through it from the supply 48, thence through contact 46, pin 45 and spiral spring 40 to the casing, the other pole of the supply being also earthed on the casing. The armature is thereby swung anti-clockwise until the pin 45 contacts with contact-spring'47, thus closing the circuit of the lamp 52 through pin 45, spiral spring 40 and the casing. The lamp is lighted until the counter-action of spring 40 breaks contact between members 47, 45, the cycle of operations being repeated when contact 46, 45 is restored. The casing of the flashing unit is provided with insulated contact members so arranged that the bulb socket contacts 22, 29 and a battery contact are connected thereto on insertion of the unit into the lamp casing. The lamp casing 1 may be made of wood, metal or insulating material with slots 2, 3 therein to receive straps, whereby it may be attached to the arm or leg of a pedestrian. Alternatively, it may be mounted on a bracket for attachment to the rear of a vehicle. The Specification as open to inspection under Sect. 91 describes also a mercury interrupter, and a construction of centrifugal control switch, Fig. 9 (Cancelled), within a housing 64 which is interposed in the tachometer drive of a motor vehicle, the contact arm 69 of the switch being adapted to swing outwardly on to a cupshaped contact 67 when the vehicle attains a predetermined speed, thereby short-circuiting the flashing apparatus and producing a steady continuous lighting of the rear lamp. This subject-matter does not appear in the Specification as accepted.