A new or improved method of and apparatus for producing 'gas caps' in miners' safety lamps for demonstration and examination purposes

摘要

465,373. Gas caps in miners' safety lamps. MANCHESTER COLLIERIES, Ltd., and EDWARDS, G. Jan. 29, 1936, No. 2621. [Class 75 (iv)] Gas caps are produced in a miners' safety lamp for demonstration and like purposes by burning the lamp in a cap-forming atmosphere within an inspection chamber, the convection currents set up by the lamp drawing into the chamber further air which draws in the inflammable vapour to create the cap-forming atmosphere. The lamp e stands on a bush d1 surrounding a central orifice d in the floor of an observation chamber a1 having one or more glass windows c, the lamp being held in position by a self-sealing sheet rubber flap g and a clamping ring g1. The windows c are provided with slots o to receive one or more apertured members p each carrying a flexible inspection hood q having a strap q1 for attachment to the face of the user. Blank shutters may be provided for the unused windows. The chamber a1 is separated by a partition b from a compartment a2 housing a container h for volatile hydrocarbon. The container h is connected to an annular member i, around which the middle of the wick j passes, and which is screwed on to a boss l carried by the partition b. Screwed into the outer end of the member i is an open-ended tube k, the inner end of which forms a valve to engage a seating on the boss l. Air entering the tube k passes through a shield bl to the bottom of the lamp chamber a1. The tube k is provided with an operating disc k1 and with. a flanged extension k2 to form a gas-tight joint. The disc k1 may be marked with a pointer to co-operate with a scale m surrounding the flange k2, whereby definite percentages of gas may be indicated. A bridge member n prevents the entry of any large obstruction. The amount of hydrocarbon drawn in by the air is controlled by the exposure of the wick according to the adjustment of the valve by the disc k1. According to the Provisional Specification, the walls of the inspection chamber may be opaque and one of them fitted with lenses or binocular openings for observation of the flame.