Abstract: A latch body (10) incorporates spring-loaded latches (11) and (12) which secure the inner tube assembly in place by latching against a shoulder in an adaptor coupling. At the lower end of the latch body (10) there are water inlet ports (13), a landing shoulder (14) and water outlet ports (15). The valve mechanism (20) includes a piston (21) slidable within upper cylinder (22) above the inlet ports (12) which has a recess (23) at its upper end for receiving a ball (24) and a sealing flange (25), at its lower end. The upper cylinder (22) has a recess (26) in which part of the ball can seat to cock the piston. A second cylinder (27) between the inlet ports (13) and outlet ports (15) carries a spring guide (28) having a valve seat (30) at its upper end. A spring (31) acts against the sealing flange (25).

Abstract: An upper end (10) for the inner tube of a core drill has a marking device comprising a pendulum (350) or hard ball (30) which runs in a circumferential track (24). The marking device adapted to be carried within a tubular upper end casing (12) which surrounds a spindle (11) which supports the inner tube of the drill. An indent washer (25) is positionable below the marking device and is oriented relative to the casing. When the upper end (10) is lifted, the marking device is driven into contact with the washer (25) and makes an impression. The orientation of the impression reveals the orientation of the drill. The impressioned washer (25) can be used to assist in noting or marking the core orientation after the drill is removed from the earth.