Patent ID: 8500357

Claim:
A locking device interacting with a drive member and comprising: an inner element ( 1 ) and an outer tube ( 3 ); wherein the inner element ( 1 ) has a first free end that projects from, and is axially displaceable from, a first end of the outer tube; a locking member ( 4 ) provided on the other end of the inner element ( 1 ), said locking member ( 4 ) permitting the inner element ( 1 ) and the outer tube ( 3 ) to be releasably locked at various axial positions relative to each other; an axially aligned torsion rod ( 7 ); and an operating member ( 5 ); wherein the locking member ( 4 ) comprises: an axially aligned thread ( 35 ), a tubular locking sleeve ( 9 ) that is slotted by at least one axially aligned slot ( 13 ), said slot including a wedge-shaped cut-out ( 113 ) with wedge surfaces ( 16 ) that are essentially tangentially aligned with the locking sleeve ( 9 ), and a wedge ( 14 ) having wedge surfaces ( 15 ), such that when said locking sleeve ( 9 ) is acted upon by a drive member ( 41 ) having a thread groove ( 42 ), said wedge surfaces are displaced along and relative to interacting wedge surfaces ( 16 ) of the locking sleeve ( 9 ), whereby the locking sleeve ( 9 ) is pressed against the outer tube to thereby axially lock the inner element ( 1 ) and the outer tube ( 3 ) relative to each other, and wherein said displacement caused by rotation of the drive member ( 41 ) about an axis that is essentially collinear with a longitudinal axis of the inner element ( 1 ), which is actuated by the torsion rod ( 7 ) being operated by the operating member ( 5 ), thereby causing the thread groove ( 42 ) to interact with the thread ( 35 ).