Patent ID: 7390035

Claim:
A self-latching device for latching, in a predetermined position, two members which are otherwise moveable relative to one another, the device comprising: (a) a latch arm having a housing with a mounting for displaceably mounting the latch arm on a first of the two members, the latch arm being displaceable along a path through the housing, the latch arm having a latch portion mounted to extend from the housing when in a latching position; (b) a retaining element adapted to be mounted on the second of the two members and providing a latching shoulder for engagement with the latch portion of the latch arm to prevent relative movement of the members from the predetermined position; (c) at least one of the latch arm and the retaining element providing a magnetic field and the other having magnetic properties arranged to cause latching engagement of the latch arm with the latching shoulder under the influence of the magnetic field when the members are in the predetermined position, whereby relative movement of the two members is substantially prevented but the latch arm is displaceable under applied force away from the retaining element to a retracted position so that the members may be moved apart; (d) a resilient biasing element associated with the latch arm to bias it towards the retracted position, but with a biasing force on the latch arm which is less than the force imparted on the latch arm by the magnetic field when the members are located in the predetermined position; (e) an actuator movably mounted on the housing and extending from the housing transversely to the path of displacement of the latch portion for receiving a displacement force to displace the latch arm from its latching position to its retracted position, whereby the two members may be moved apart away from the predetermined position; (f) a connector for connecting the actuator and the latch arm to transmit the displacement force from the actuator to the latch arm so that it can be displaced from its latching position to its retracted position and for leaving the actuator free to move relative to the connector upon removal of the displacement force; and (g) a second biasing element for returning the actuator to its initial position on removal of the displacement force leaving the biasing element to maintain the latch arm and connector substantially in its retracted position, whereby when in the predetermined position the latch arm is displaceable under the magnetic forces against the biasing means to re-establish its latching position; and (h) wherein the connector comprises a carriage with spaced guides for sliding along tracks in the housing, the latch arm is in the form of an elongate pin and the biasing element is in the form of a helical compression biasing spring mounted around the pin.