| 摘要 |
A mechanism for selectively locking a stationary element and a movable element mounted on the stationary element. The mechanism comprises a pawl block mounted within a casing for sliding movement in opposite first and second directions along a first axis substantially transverse to an engagement surface on the stationary element. The pawl block has a substantially "V"-shaped cavity defined by two ramp surfaces which, together with the engagement surface, define a substantially triangular recess. A striated roller member is mounted within the recess for simultaneous circumferential engagement with the engagement surface and at least one of the inclined ramp surfaces when the pawl block is in its locking configuration. A wedge block is movable in opposite third and fourth directions along a second axis generally transverse to the first axis, between a blocking position, whereat the wedge block wedgingly engages the pawl block into the locking configuration, and a withdrawn position, whereat the wedge block is removed from such wedging engagement so as to permit movement of the pawl block from the locking configuration to an unlocked configuration. |
