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Show BUREAU OF MINES APPROVES THIS LAMP Two improved forms of Ct-E miners' Inmp have been recently approved by the United States bureau bu-reau of mines (Appnnal Nos. 13 and 13 A, Schedule Sched-ule 6-A). "Form C" has a case of drawn and folded sheet steel, while the "Form D" battery container consists of one-eighth inch aluminum alloy casting, 91 per cent pure aluminum. Otherwise Other-wise the lamps are Identical. The cap lamp is a steel shell lined with fibre insulation and contains the reflector of porcelain porce-lain enameled steel and phospher bronze spring contacts rigidly mounted. These latter hold the Mazda lamp bulb in such manner that it is shattered shat-tered and expelled from the contacts by n blow that would be only sufficient to crack or chip the glass bulb as usually mounted. This prevents the heated filament coming in contact with inflammable in-flammable gaseous air. Double steel hooks electrically welded together and riveted to the shell provides means for attaching at-taching the lamp to the miner's cap. The cap lamp is waterproof and weighs about four ounces. The weight on the cap is about six or eight ounces, depending upon how the lamp and cable are worn. (i. 1). Form C, Miners' Portable Electric Lamp Outfit, Showing Exterior nnd Interior Views. Courtesy Halt Irfike Mining Itcvlew The lamp is a one-half candlejwwcr wire drawn mazda with a guaranteed life of three hundred hours. It has two contact bases, and a single filament running straight through the bulb together to-gether with the reflector produces a well diffused dif-fused illumination at an angle of a hundred nnd thirty degrees. A forty-threc-inch cable connects con-nects the lamp to the battery. This is ample for the unrestricted movement of the miner. It is doubletwisted, strand copper, rubber coated individually, laid together and the whole rubber coated. The weight is about eight ounces. This construction gives n strong, light, flexible, nonkinking cable, of low resistance. Protection at each end is afforded by steel spring nrmor, double at the battery and single at the lamp. The cable is fastened In the lamp and battery bat-tery cover entrance bushings by rubber packings pack-ings secured with lock nuts. It will stand n very heavy strain without loosening or putting undue strain on the tcrminnls of the conductor. The case for the "Form C" is of two pieces of drawn sheet steel folded and electrically welded with horizontal corrugations on the front. The cover is of cast aluminum in one piece, including entrance bushing and hingepln. When the cover is closed phospher bronze spring contacts on the inside engage the terminal studs of the battery at three points on each stud, insuring perfect I contact with a maximum contact surface. These contacts are mounted on fibre insulating blocks riveted to the cover nnd exert a constant pressure pres-sure on the studs, preventing loose contnet or movement of the battery in the case. The cover locks with a very simple, rugged, sclfacting, double latch lock that unlocks with a key. Tampering Tam-pering is impossible without detection. The case for the "Form D" is of aluminum alloy, one-eighth inch thick in a single piece with hinge slot, belt straps nnd parts which arc engaged en-gaged by the lock. Otherwise it is identical with the "Form C." Both forms have approximate outside dimensions of: Thickness two Inches, height six nnd one-naif inches, nnd width five inches. Total weights arc "Form C," four pounds seven ounces; "Form D," four pounds thirteen ounces. All metal parts are finished with a semi-transparent, acid-proof, baking vnrnish, which gives a very serviceable and pleasing gray finish. The bnttery is an "iron-clad oxide" (Iron-clad positive plate and "cxlde" negative). It is guaranteed guar-anteed to glvo service for not less thnn ten nnd three-quarter hours per chnrgo throughout a period of two years. The plates arc contained in a medium hard rubber, non-spllinblc case, ribbed vertically for strength nnd sealed with a special vent and filling plug. The cover is so construct-, cd that the pressure of the contacts on the ter , initials strengthens the seal. All parts of the I entire outfit arc interchangeable. No gas is generated on discharge and explosions are therefore there-fore impossible. Automatic charging racks are not part of tie equipment but can be furnished to take care of any requirements. Each battery space on the charging board is provided with the proper resistance re-sistance unit, so that, regardless of the number of batteries on charge, the proper current is an-1 tomatically maintained. The phospher bronze spring contacts arc of such form and arrange-1 merit that the bnttery cannot be inserted incorrectly. incor-rectly. Tho proper jolnrity is absolutely necessary neces-sary to secure contact. A single motion of the hand places the battery on the charging board and automatically cuts it into the charging circuit. cir-cuit. The advantages of this outfit are ignition of mine gas is impossible; neither bnttery nor lamps can be short circuited ; the battery gives a full, steady illumination for the entire shift; failures, except as the result of accident, are im-possible; im-possible; it will operate submerged In water; safe, durable, efficient and easy to wear; the light cannot be extinguished except by intentional inten-tional disabling; the outfit may be sealed, so tampering will be rendered visible. |