THE EJECTOR.
Fig. 36.
The position of the ejector in the cut can be clearly seen in [Fig. 36], where there is also a diaphragm to be seen under the deck where it is located when used to operate driver brakes. The ejector is operated on the same principle as the water injector, only it is used to lift air instead of water. A cross-section of the injector is shown in [Fig. 36]. When the engineer wishes to apply the brake, he pulls the handle 41 (broken off in the cut), which opens the valve B49, and admits steam to the body of the ejector A1. The steam rushes upward round the end of the tube 5, its velocity being accelerated in passing through the contracted opening left round the top of the tube. Passing through tubes 3 and 6, the steam shoots up in the form of a column with a hollow base; the tube 5, which is connected with the pipes and diaphragms on the train, forming this base. The effect of the steam passing out under these conditions is to induce a current through the tube 5, which draws up the valve B7, and sucks the air out of the pipes and diaphragms. A vacuum being thus formed in the diaphragms, the atmosphere presses the flexible ends together. This tendency to collapse is retarded by the brake-rod connections, and the latter receive a pull equal to the combined atmospheric pressure on the diaphragm. The brake-levers are arranged to transmit a proper tension to the brake-shoes for making the brake effective. A vacuum gauge placed on the front of the ejector enables the engineer to regulate the power as he wants it. The brake is released by pushing on the lever 24, which opens the valve 8, and admits air into the brake-pipes. The release-valve attachment is sidewise in vertical section cut through the handle, and is put separate for convenience of illustration.