Abstract: A locking device for locking a first part of a container to a second part of the container when the container is in a first position and releasing the first part when the container is in a second position, the locking device comprising latch means attached to the first part of the container; a housing disposed on or in the second part of the container; and a moveable member arranged for movement in said housing; such that in said first position said latch means engages said housing to prevent the first part from separating from the second part of the container and in said second position the moveable member, under the action of gravity, engages the latch means to displace the latch means from the housing thereby releasing the first part from the second part of the container enabling ejection of any contents of the container.