Show lamp approved by bureau of mines M ines contributed D two improved forms oll oi GE G E miners lamp have been recently appi approved oved by the bureau of mines approval nos 13 and schedule 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 the lamps are identical the cap lamp is a steel shell lined with fibre fabre insulation and contains the reflector of porcelain enameled steel and prospher pher bronze spring contacts rigidly mounted these latter hold the mazda lamp bulb in such manner that it is shattered and expelled from the contacts by a bow 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 gaseous air double steel hooks electrically welded mill Q G E form 0 miners portable electric lamp outfit showing exterior and interior views together and riveted to the shell provide means for attaching the lamp to the miners cap the cap lamp is waterproof and weighs about four ounces the weight on the cap is about six or eight ounces depending on how the lamp and cable are worn the lamp is a one half candlepower candle power wire drawn mazda with a guaranteed life of hours it has two contact bases and a single filament running straight through the bulb together with the reflector produces a well diffused illumination at an angle of degrees A forty three inch cable connects the lamp to the battery this is ample for the unrestricted movement of the miner it is double twisted strand copper rubber coated individually laid together and the whole rubber coated the weight is about eight ounces this construction gives a strong light flexible king cable of low resistance protection at each end is afforded by steel spring armor I 1 double at the battery and single at the lamp the cable is fastened in the lamp and battery cover entrance bushings by rubber pack ings secured with lock nuts it will stand a very heavy strain without loosening or putting undue strain on the terminals 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 hinge pin when the cover is closed prospher pher bronze spring contacts on the inside engage the terminal studs of the battery at three points on each stud insuring perfect contact with maximum contact surface these contacts are mounted on fibre fabre insulating blocks riveted to the cover and exert a constant pressure on the studs preventing loose contact or movement of the battery in the case the cover locks with a very simple pimple rugged self acting double latch lock that unlocks with a key tampering 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 and parts which are engaged by the lock otherwise it is identical with the form C both forms have approximate outside dimensions men of thickness two inches height six and one half inches and width eidth five nv inches total weights are form C t four pounds seven ounces form D four pounds thirteen ounces all metal parts are finished with a semitransparent acid proof baking varnish which gives a very serviceable and pleasing gray fin finish 1 sh the battery is an ironclad iron clad egide ironclad iron iroll clad positive plate and egide negative it is guaranteed to give service tor for not less than ten and three quarter hours per charge throughout a period of two 0 years the plates are contained in a medium hard rubber non case ribbed vertically for strength and sealed with a special vent and filling plug the cover is so constructed that the pressure of the contacts on the terminals strengthens the seal all parts of the entire outfit are interchangeable ter changeable no gas is generated on discharge and explosions are therefore impossible automatic charging racks are not part of the equipment but can be furnished to take care of any requirements each battery space on the charging board is provided with the proper resistance unit so that regardless of the number of batteries on oil caliari charge ge the proper current is automatically maintained the phosphor bronze spring contacts are of such form and arrangement ran gement that the battery cannot be inserted incorrectly the proper polarity is absolutely necessary to secure contact A single motion of the hand places the battery on the charging board and automatically cuts it into the charging circuit the advantages of this outfit are summed up as follows ignition of mine gas is impossible neither battery 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 impossible it will operate submerged in water safe durable efficient and easy to wear the light cannot be extinguished except by intentional disabling the outfit may be sealed so tampering will be rendered visible |