Door operating apparatus

Claim 1

AN AUTOMATIC DOOR OPENING APPARATUS FOR A GARAGE FORMED WITH AN ACCESS OPENING HAVING A HEADER AT ITS UPPER DIMENSION, SAID APPARATUS COMPRISING A DOOR HAVING FRONT BACK WALLS DEFINING TOP, SIDE AND BOTTOM DOOR EDGES BETWEEN THEM, SAID DOOR BEING MOVABLE BETWEEN A CLOSED POSITION IN WHICH IT IS SUBSTANTIALLY VERTICAL AND BLOCKS ACCESS THROUGH SAID OPENING AND AN OPEN POSITION IN WHICH SAID ACCESS IS UNBLOCKED, MEANS CONTINUOUSLY URGING SAID DOOR FOR MOVEMENT AT LEAST INITIALLY IN THE SUBSTANTIAL DIRECTION OF ITS VERTICAL AXIS PAST SAID HEADER TOWARD SAID OPEN POSITION, MEANS FOR RETAINING SAID DOOR IN SAID CLOSED POSITION, SAID RETAINING MEANS INCLUDING A PAIR OF SPACED BRACKETS FIXED TO SAID DOOR AT SAID TOP EDGE AND EXTENDING UPWARDLY FROM SAID TOP EDGE, SAID BRACKETS BEING FORMED WITH ALIGNED APERTURES, A ROLLER JOURNALED IN SAID APERTURES FOR ROTATION ABOVE SAID DOOR BETWEEN THE PLANES OF SAID FRONT AND BACK WALLS, AND A TONGUE FIXED TO A SOLENOID MOUNTED ON SAID HEADER, SAID TONGUE ABUTTING SAID ROLLER WHEN SAID DOOR IS IN SAID CLOSED POSITION TO BLOCK MOVEMENT OF SAID DOOR FROM SAID CLOSED POSITION, AN ELASTIC FLUID RESERVOIR DISPOSED NEAR SAID DOOR IN POSITION TO ENABLE A VEHICLE APPROACHING SAID DOOR TO CONTACT AND COMPRESS A PORTION OF SAID RESEVOIR, AND A SWITCH FOR CONVERTING A CHANGE IN FLUID PRESSURE IN SAID RESERVOIR INTO A CHANGE IN QUANTITY OF ELECTRICAL ENERGY, SAID CHANGE IN ELECTRICAL ENERGY CAUSING SAID SOLENOID TO WITHDRAW SAID TONGUE FROM A POSITION ABUTTING SAID ROLLER TO PERMIT SAID DOOR TO MOVE TOWARD SAID OPEN POSITION.