Electro-magnetic release mechanism

aaaAn electro-magnetic mechanism comprises a spring-operated rod having a recess and a latching member engageable in the recess to block motion of the rod. A release member retains the latching member engaged in the recess 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. A magnet retains the release member in the first position and the mechanism includes an element such as a spring for urging the release member to the second position. A coil is arranged to demagnetize the magnet at least such that the release member moves to the second position, the latching member is disengaged from the recess and the rod moves axially by spring force.