Abstract: The present invention relates to a locking device (4) for a wire line core drilling system comprising an inner tube (2) by means of which core samples are collected, and an outer tube (1) connected to a drill bit, which locking device is applied in the rear end of the inner tube. The locking device (4) comprises locking members (7, 9) so designed that, when the inner tube has been inserted into the outer tube and has assumed the correct position inside the outer tube for drilling, in one and the same movement it simultaneously effects mechanical locking of the inner tube (2) in relation to the outer tube (1) and release of a gripping means (10; 25) of an accompanying device (5; 26) connected to the inner tube.

Abstract: The present invention relates to a method for a valve, which valve comprises a movable valve body (6) having a first side (9) facing a means for supplying pressurized fluid and influenced in the supply direction by a force from said fluid, and a second side (11) influenced in opposite direction by a force from said fluid, which valve is provided with at least one connection (8) connecting the first side (9) of the valve body with the second side (11) of the valve body, and also comprising a spring (20) for opening the valve by displacing the valve body from a closed position to an open position, said method comprising the following steps: a pressurized fluid is supplied to the valve in closed position so that the valve remains closed; the supply of pressurised fluid to the closed valve ceases, a force equalization then occurs between said first (9) and second (11) sides thereby enabling the spring to open the valve, and a pressurized fluid is supplied to the valve in open position and the valve remains open.