Mechanical time delay security latches and methods

A method of controlling access to a region of an aircraft, the method comprising:

• providing a barrier that is movable between a closed position, in which access to the region of the aircraft is restricted by the barrier, and an open position, in which access to the region of the aircraft is unrestricted by the barrier;
• providing a time-delay latch for the barrier, the latch comprising:
• a housing;
• a fluid chamber contained within the housing for holding fluid within the fluid chamber;
• a pin that extends through the fluid chamber and is axially movable within and through the fluid chamber from an unlatched position, in which the latch is configured to resist movement of the barrier, to a latched position, in which the barrier is movable without resistance from the latch, and from the latched position to the unlatched position;
• and
• a release frame movably secured within the housing;
• positioning the pin in the latched position, in which the release frame engages with the pin to prevent the axial movement of the pin, relative to the fluid chamber;
• and
• moving the release frame to disengage the release frame from the pin, such that the pin automatically moves from the latched position to the unlatched position;
• wherein moving the pin between the latched position and the unlatched position requires a prescribed duration of time to elapse, which is more time than is needed to move the pin from the unlatched position into the latched position.

An aircraft comprising:

• a region of the aircraft to which access must be temporarily restricted;
• a barrier that is movable between a closed position, in which access to the region of the aircraft is restricted by the barrier, and an open position, in which access to the region of the aircraft is unrestricted by the barrier;
• and
• a time-delay latch for the barrier, the latch comprising:
• a housing;
• a fluid chamber contained within the housing for holding fluid within the fluid chamber;
• a pin that extends through the fluid chamber and is axially movable within and through the fluid chamber from an unlatched position, in which the latch is disengaged from the barrier to allow movement of the barrier, to a latched position, in which the latch is engaged with the barrier to restrict movement of the barrier, and from the latched position to the unlatched position;
• and
• a release frame movably secured within the housing;
• wherein the release frame is configured, when the pin is in a latched position, to engage with the pin to prevent the axial movement of the pin and, when the pin is in an unlatched position, to disengage from the pin to allow the axial movement of the pin;
• wherein the axial movement of the pin between the latched position and the unlatched position requires a prescribed duration of time to elapse;
• and
• wherein the latch is configured such that axial movement of the pin between the unlatched position and the latched position occurs faster than the prescribed duration of time.