Patent GB-478068-A (GB)
Title: Improvements in or relating to lamps for use in mines and other places
IPC: F21V33/00
Filed: 1936-07-14
Abstract: 478,068. Miners' &c. lamps. OLDHAM & SON, Ltd., and HOLT, jun., H. July 14, 1936, No. 19557. [Classes 39 (ii), 75 (i), 75 (iii), and 75 (iv)] For use by miners and others, an oil lamp and an electric lamp are assembled to form a composite unit, the oil lamp serving as a gas detector and being movable relatively to the electric lamp from an upright operative position to an inverted inoperative position. The oil lamp is lit by means of a wire or filament rendered incandescent by current from the electric lamp, it is removably hinged or pivoted to the electric lamp, and when in the inoperative position preferably lies close thereto. In the form shown, a battery container 1 is made of moulded rubber, ebonite composition, or synthetic resin, and is formed interiorly into two or more compartments and exteriorly with ribs 1<1>. A cover for the container is formed by two annuli 6, 7 cast integrally, or rigidly interconnected, and provided with projections 12 to receive the steel hooks 14 of a leather handle 13. A two-filament bulb 9 fits into a brass or like sleeve 15 which carries an insulation pin 16 provided with spring loaded plungers serving as contacts for the bulb, these parts being carried by an arm 19 which is slidable along the inner surface of the annulus 6 by means of a knob 20 for focusing the bulb with respect to a reflector 8. The annulus 6 also carries an insulating block 21 for two differently-sized charging sockets 23, 24 which, after charging, are covered by an external sliding shutter which is sealed by a lead rivet. Additional plug holes for charging purposes may also be provided on the side of the container 1. The annulus 7 also contains a switch 11 for the bulb 9 operated by an external knob. The oil lamp comprises a reservoir 38 to which a combustion chamber 39 is hinged at 72, the chamber 39 carrying a lug 82 to cover a screw 83 for the filling hole, sealing being effected by means of a screw and lead rivet. The wick 42 is encased in a tube 60 surrounded by a sleeve 60<1> connected to a bracket 61 which receives one end of a rod 62 encased in a sleeve 64 and moved up and down to adjust the wick by means of a knob 63. The sleeve 60<1> is enclosed by a fixed tube 84. The chamber 39 is provided with an observation window 66 and with ventilation holes protected by two or more concentrically arranged gauzes 70. The upper gauzes 40 are surrounded by a cover 75 having internal baffles 76, 77 opposite its outlet holes. The cover carries a flanged ring 78 which screws into the chamber' 39 and is correctly located by means of a spring-loaded pin 79. The wick 42 is lit by a filament 41 which is pushed into position and connected to the battery only when the switch 40<1> is depressed. The oil lamp is pivoted to the electric lamp by means of a pin 53 and pivots 43, 65 cast on the cover 6. The oil chamber 38 is formed with an inter-compartment wall 54 which accommodates a circular piece of ebonite 52 carrying a crescent-shaped contact 51 into which is screwed one end of a conducting member 55 surrounded by an insulating sleeve 56. The other end of the member 55 carries a spring- controlled carriage 57 for the filament 41, the carriage being operated by means of the switch 40. The crescent-shaped contact 51 co-operates with a spring-loaded contact 50 (not shown) on the hinge, the arrangement being such that the current can be supplied to the filament only when the oil lamp is in the upright operative position. The Provisional Specification refers to the use of a magnetic lock for the sliding shutter of the charging sockets, a single filament bulb with a corresponding switch, and to a leaf spring for supporting the igniting filament, the latter being made of platinum, platinum alloy, or the material known under the Registered Trade Mark " Nichrome."