Abstract: This automatic release and ejection locking mechanism for said equipment boxes, notably for aircraft comprises locking balls releasable from their locked condition by means of a piston constantly urged by a coiled compression spring to its release position. The locking means are held against the force of the ejection spring by means of an effort scalingdown device, so that the force to be applied to said device for keeping the locking action may be very moderate and the release can be obtained by reducing or cancelling the low retaining force exerted on the effort scaling-down device, for example by means of electromagnetic release means, in combination or not with a permanent magnet. (FIG.