III–E–10

This pump is used to transfer oxygen from large high pressure cylinders to the small army breathing apparatus cylinders.

On the outside of the wooden case in white painted letters is the marking: "Sauerstoff - Umfüllpumpe". A metal instruction plate on the pump also refers to it by the same name, however, it may be also called a "Sauerstoff-Handumfüllpumpe".

The pump is contained in a field gray, steel reinforced, wooden case measuring 37 x 24.2 x 15.5 inches. The case is provided with a removable lid held in position by four lat-ches and also with two carrying handles located on the ends of the case. The case has two sets of bolt openings which correspond to the bolt open-ings in the base of the pump frame. One set is in the side of the case used to bolt the pump for shipment while the other is in the removable lid to be used to mount the pump in a working position. In one corner of the case is a small wooden box, probably meant for spare left. Also inclu-ded in the case are three metal pressure hoses (used to connect the pump to the oxy-gen cylinders), an operation and description sheet, a parts list and a drawing of the ap-paratus.

The pump itself weighs 123 pounds. It consists of a piston rod, each end of which operates in a cylinder fitted with suction and pressure valves, the two suction valves being attached to one line and the two pressure valves to another. The suction line leads to the connection fitting of the oxygen stock bottle, the pressure line to the con-necting fitting of the breathing apparatus cylinder. The piston rod slides up and down the cylinders operating the pressure valve in one and the suction valve in the other. Since both valves open only in the direction from the stock bottle to the breathing set cylin-der, a return flow to the stock bottle is impossible. The oxygen is therefore forced by the piston into the breathing set cylinder; there are gauges on both the pressure and suction sides.

The two cylinders are fastened to the pump frame which is mounted up-right on a cast iron stand, the piston rod being operated by a hand lever.

III–E–10