HYDRAULIC DOUBLE TELESCOPIC PROP

摘要

The double telescopic prop is composed of an external cylindrical jacket tube (1), an inner tube (2) displaceable therein, and a run-out piston rod (3). The hydraulic fluid used for run-out of both prop stages is conducted via a connection (14) to the inner tube (2) piston (5) and via a check valve to the piston (7) of the piston rod (3). The upper prop is run in when the hydraulic liquid flows into the outer ring area (11) between the cylindrical jacket tube (1) and the inner tube (2) via the connection (17). An advantageous size ratio of maximum 8.5:1 is provided for upper prop run-in between the piston surface of the inner tube (2) and the ring surface of the ring area (11).