Abstract: An electro-magnetic mechanism comprises a spring-operated rod (1) having a recess (1a) and a latching member (2) engageable in the recess to block motion of the rod. A release member (4) retains the latching member engaged in the recess (1a) in a first position of the release member and allows the latching member to be disengaged from the recess in a second position of the release member (4). A magnet (5) retains the release member in the first position and the mechanism includes an element such as a spring (7) for urging the release member (4) to the second position. A coil (8) is arranged to demagnetize the magnet (5) at least such that the release member moves to the second position, the latching member (2) is disengaged from the recess (1a) and the rod (1) moves axially by spring force.