Protecting Mine Rescue Workers from Gas 



A new type of breathing apparatus sup- 

 plies oxygen in just the right quantities 



IN January, 1914, the director of the 

 Bureau of Mines commissioned Mr. 

 WilHam E. Gibbs, a mechanical engineer 

 of New York City, to design a new type of 

 apparatus for use in mine disasters. 



The new apparatus has many points 

 of superiority over those which have 

 been used formerly. By means of a 

 special device, oxygen is supplied to the 

 wearer at the rate it is used. 

 While sufficient is available 

 when the wearer is working, 

 none is wasted when he is 

 resting. The harder a man 

 works the more oxygen is 

 necessary for him. 



The flow of oxygen 

 may be regulated by 

 means of a valve which 

 is very easy to operate. 

 When this reducing 

 valve is attached to a 

 cylinder of gas, it is 

 possible to admit oxy- 

 gen to the breathing bag 

 in the exact quantity re- 

 quired by the user. 



The new breathing ap- . 

 paratus is constructed of x.'^^^j^" 

 metal, with the excep- 

 tion of a rubber gasket. 

 All parts of the apparatus 

 are mounted on a frame 

 of steel tubing which is 

 carried on the back. When in use, the 

 entire apparatus is protected by an alum- 

 inum cover. The oxygen is carried in a 

 cylinder or bottle at the bottom of the ap- 

 paratus. This cylinder has a stop valve 

 connected with the reducing valve, from 

 which the gas passes by way of a tube past 

 the safety valve within the breathing bag. 

 The safety valve has a 

 whistle in its outlet. 

 This whistle gives warn- 

 ing of leakage at the 

 reducing valve. When 

 the wearer breathes, air 

 from the breathing bag 

 lifts the inhalation 

 valve and passes 

 through a flexible tube 

 and mouthpiece to the 



lungs. The exhaled breath passes to the 

 exhalation valve down a flue to the ab- 

 sorber where it is converted, then up 

 through the cooling can, where it loses its 

 heat, and then into the breath- 

 ing bag. When the supply of 

 oxygen in the bag gets low, the 

 flap opens the admission valve 

 and a fresh supply enters. 



The absorbing can contains 

 twenty vertically arranged 

 sheets of fine iron-wire 

 gauze, held parallel to 

 each other one-fifth of 

 an inch apart. Before 

 being inclosed in the can 

 this bundle of gauze 

 sheets is dipped into 

 molten caustic soda con- 

 taining twenty per cent 

 of water. The mixture 

 solidifies on the 



itKing 



._j5afety 

 valve 



Reducing vaVvfe 



.Carbon- dioxide 

 absofbeK 



A mine rescue worker wearing the new 

 breathing apparatus. The aluminum 

 cover is broken away to show interior 



The reducing valve automatically regu- 

 lates the flow of oxygen from the tank 



on 

 gauze when cool, 

 forming reinforced 

 plates about one- 

 sixteenth of an inch 

 thick. This makes 

 an absorber of carbon 

 dioxide. The plates 

 maintain a uniform sur- 

 face from which the con- 

 densed and chemically 

 produced moisture con- 

 stantly drains away, car- 

 rying with it the newly formed sodium 

 carbonate. The capacity of this absorber 

 is practically constant, until the active 

 material is all used. 



The apparatus is completed by a pressure 

 gage (finimeter) which is read by touch 

 instead of by sight, because, in the dark- 

 ness of a mine disaster, it would be im- 

 practicable to depend 

 on sight. This gage 

 sounds an alarm when 

 the oxygen in the cylin- 

 der has been reduced 

 beyond the point of 

 safety. 



Instead of a helmet 

 a simple mouthpiece 

 and nose clip are used 

 with the apparatus. 



830 



