APPARATUS FOR SENDING EARTH AND SAND UNDER PRESSURE.

摘要

The device for sending earth and sand under pressure, consisting of an outer cylinder (16), an inner cylinder (19) adapted to be moved by a first piston (21), which is slidably provided in the outer cylinder. The piston moves in such a manner that the open end portion (19a) faces the interior of the earth and sand tank (10) and is displaced towards and away from the inlet (11a) of a force feed pipe (11). A piston rod (20) drives a third piston (23) provided in the inner cylinder (19) and is used to force feed the earth and sand. The first piston provided in the outer cylinder is made annular, and the end portion (20b) of the piston rod is extended through the end portion (19b) of the inner cylinder (19) and first annular piston (21). A second piston (22) provided at the same end portion (20b) is slidable in the outer cylinder (16).