Patent GB-190819202-A (GB)
Title: Improvements in or relating to Apparatus for Igniting Miners Safety Lamps.
Inventor: HAILWOOD ERNEST ARTHUR
IPC: F21L23/00
Filed: 1908-09-12
Granted: 1909-09-13
Abstract: 19,202. Hailwood, E. A. Sept. 12. [Patent of Addition to No. 28,255, A.D. 1907.] Miners' safety lamps.- Apparatus for electrically igniting miners' safety lamps is provided with improved casings or chambers, doors, doorattaching devices, and electric switches in connexion with such doors. In one form, Fig. 1, there are two chambers, which may be formed in one casting, a chamber A for the coil F, and a chamber B for the generator or accumulator G. The coil chamber A is provided with a circular screw-threaded opening to receive a threaded door C', attached by means of a hinged plate D having a slot D<1> for the reception of a handle or boss on the door, so that the door is free to be unscrewed. The plate D is hinged at D<2>, and the end D<3> is suitably hinged or turned around a bar E<1>, which serves as hinge for an outer or long door E. This outer door covers the circular door and closes the generator chamber B, and may be constructed with flanges E<2> or distancepieces, which leave a ventilation gap around the opening of the generator chamber. Additional guarded ventilation gaps V may be provided. In the generator chamber B an insulator G<1> prevents the terminals from accidentally touching the walls of the chamber, and the terminals may be arranged as shown in Figs. 1 and 5, the conductors G<7>, G<10> being electrically connected by springs G<5>, G<9> surrounded by insulating-sleeves G<3>, G<8>. The door E is provided with a locking- device, such as L, L<1>, to which a padlock can only be attached when the circular door C<1> is driven right home. The lamp ignition contact-piece in the base of the lamp chamber terminates in the chamber A,. and insulated wires lead into the upper portion J above the lamp chamber, containing guard ahd sweep gear and switch mechanisms ; and to ensure a flame-tight joint, the cover J<1> screws on to the body J and is locked by a device such as L<3>. The screwing-down of the cover J<1> causes an insulated contact member S to bridge a gap in the electric circuit. Other switches may be arranged to close only on the closing of the door of the lamp chamber. In a modification, the circular door and dooropening are not threaded, and the door is arranged to bridge a gap in the electric circuit when firmly closed. To ensure a flame-tight joint, a rubber ring is fixed around the opening, or on a flange on the door, by means of a junk ring or by set-screws &c. The door may be secured by a bayonet-joint arrangement, Fig. 3, in which projections C<2> on the door are pressed into angle recesses C<3>, which on their longer arms slope slightly inwards to tighten the door on its seat, and the projections C<2> may operate switches hidden in the recesses C<3>. The circular door may be secured to the casing by a ring and chain, or by a hinge as shown in Fig. 1. The bayonet-joint, may be dispensed with, in which case the closing and locking of the long door will press the door C' home and ensure a name-tight joint. In a further form, Fig. 7, a single chamber is employed, coil or dynamo M is used instead of an accumulator, and the outer door E is dispensed with. The door C<1> is threaded, and switch members S, not diametrically opposite, are closed on the complete screwing-home of the door C<1>. A handle H is mounted on a shaft H<1>, which carries a clutch member such as H<2> engaging a ratchet member M<3> on the dynamo shaft when the door C' is shut, so that the dynamo may then be actuated. The door C' may have a lock device L, and a fuse may be inserted in the electric circuit.. In a further modification there are two chambers, a rectangular lamp chamber having a circular door somewhat of the type shown in Fig. 1, and a generator chamber. A sliding door or rod is arranged so that it can only be closed when the circular door is closed, and the sliding door &c. has an aperture which will then coincide with the handle shaft and dynamo shaft, so that only then can the dynamo be operated. If an accumulator is used, the aperture may coincide with push or switch members. The sliding door or rod may take the place of the long door E in the other forms of the apparatus. According to the Provisional Specification, the circular door may be dispensed with, being replaced by a suitable projection on the long door, which makes the coil chamber perfectly gas-tight, while permitting ventilation of the generator chamber.