first and second decompression locks;

said first decompression lock includes a first support carriage;

said second decompression lock includes a second support carriage;

each said support carriage includes a swivelling locking latch longitudinally displaceable in a base;

said displacement of said support carriage is achieved by pressure acting on slide bevels;

a common spring;

said common spring acts between said first and second support carriages;

each of said decompression locks includes a locked and an unlocked position;

each said support carriage is temporarily displaced against the force of said common spring during a change in position from locked position to unlocked position;

each said support carriage includes a leaf spring whose outer end holds said swivelling locking latch in a locked position and releases it when a certain excess pressure is reached;

each said leaf spring has one arm and the outer end of said leaf spring arm exerts pressure resiliently on said swivelling locking latch and engages releasably in a notch of said swivelling locking latch;

said first and second decompression locks are located adjacent to one another on said base to act in offset opposite directions;

said outer end of said swivelling locking latch of said first decompression lock and said outer end of said swivelling locking latch of said second decompression lock are offset in relation to one another and point in opposite directions; and,

said common spring resides between support carriages exerting pressure to move said support carriages in their displacement direction.