Door closing door checks

Claim 1

IN A DOOR CHECK INCLUDING A CYLINDER HAVING A HEAD AT EACH END THEREOF, A PISTON RECIPROCABLE IN SAID CYLINDER HAVING A PISTON ROD EXTENDING THROUGH ONE CYLINDER HEAD, SPRING MEANS IN SAID CYLINDER CONSTANTLY URGING SAID PISTON TOWARD THE OTHER CYLINDER HEAD, THE SAID CYLINDER AND PISTON ROD BEING CONNECTABLE TO A DOOR FRAME AND DOOR IN A MANNER TO CAUSE SAID PISTON TO MOVE IN ONE DIRECTION AND COMPRESS SAID SPRING RESPONSIVE TO MANUALLY OPENING SAID DOOR, SAID SPRING CAUSING SAID PISTON TO MOVE IN THE OPPOSITE DIRECTION AFTER SAID DOOR HAS BEEN OPENED TO CLOSE THE SAME, SAID CYLINDER HAVING A BLEED IN THE OTHER OF SAID HEADS ADAPTED TO REGULATE THE RATE OF THE SAID SPRING CLOSING OF SAID DOOR, AN AUTOMATIC HOLD-OPEN AND MANUAL RELEASE MEANS COMPRISING A SPRING LOADED SLIDING ELEMENT CARRIED BY SAID ONE CYLINDER HEAD BIASED TOWARD SAID PISTON ROD, SAID PISTON ROD HAVING A GROOVE THEREIN SUITABLY LOCATED TO RECEIVE SAID LATCH ELEMENT WHEN SAID DOOR IS SWUNG FULLY OPEN WHEREBY TO MAKE SAID DOOR CHECK INOPERATIVE TO CLOSE THE SAME, AND A SINGLE RELEASE BUTTOM CONNECTED TO SAID LATCH ELEMENT EXTENDING FROM ONE SIDE OF SAID ONE CYLINDER HEAD MANUALLY PUSHABLE TO RELEASE SAID LATCH AND PERMIT SAID DOOR CHECK TO FUNCTION NORMALLY TO CLOSE THE DOOR.