Jack assembly

Claim 1

A JACK, COMPRISING: A BRACKET ADAPTED TO BE SECURED TO THE UNDERSIDE OF A STRUCTURE, SAID BRACKET BEING PROVIDED WITH A PAIR OF PARALLEL SIDE WALLS HAVING ALIGNED, VERTICAL SLOTTED OPENINGS THERETHROUGH ADJACENT THEIR FORWARD EDGES; A TUBULAR LEG MEMBER SUPPORTED BY AND NORMALLY DEPENDING FROM SAID BRACKET, THERE BEING MEANS ADJACENT THE UPPER END OF SAID LEG PIVOTALLY SECURING THE SAME TO AND BETWEEN SAID BRACKET SIDE WALLS IN A MANNER WHEREBY SAID LEG CAN BE SWUNG FORWARDLY AND UPWARDLY ABOUT SAID CONNECTION FROM ITS NORMAL VERTICAL POSITION TO A HORIZONTAL POSITION; A SHAFT LONGITUDINALLY ADJUSTABLY CARRIED IN AND PROJECTING FROM THE LOWER END OF SAID LEG, SAID SHAFT HAVING A BASE ON ITS LOWER END; A RETAINING BAR VERTICALLY SLIDABLY CARRIED BY AND BETWEEN THE SLOTTED OPENINGS IN SAID BRACKET SIDE WALLS, SAID RETAINING BAR BEING MOVABLE FROM A POSITION AT THE BOTTOM OF SAID SLOTTED OPENINGS WHEREIN IT PREVENTS UPWARD SWINGING MOVEMENT OF SAID PIVOTAL LEG MEMBER, TO A POSITION ADJACENT THE TOP OF SAID SLOTTED OPENINGS WHEREIN IT WILL NOT INTERFERE WITH THE UPWARD AND FORWARD SWINGING OF SAID LEG TO A HORIZONTAL POSITION; AND MEANS ON SAID JACK ADAPTED TO RELEASABLY MAINTAIN SAID LEG MEMBER IN A HORIZONTAL POSITION.