Patent ID: 7543410

Claim:
A door operator, comprising: a pneumatic gas source; a pneumatic motor coupled to a door; a first pilot valve in fluid communication between the pneumatic gas source and the pneumatic motor, wherein the first pilot valve rests in a neutral position that does not allow the passage of gas from the gas source to the pneumatic motor, thereby maintaining the pneumatic motor unactuated; and a first check valve and a second check valve in fluid communication with the first pilot valve, wherein the pneumatic gas source delivers gas to the first pilot valve to maintain the first pilot valve in the neutral position, further wherein actuating one of the first check valve and the second check valve vents gas from the first pilot valve facilitating shifting of the first pilot valve to a respective one of a first position and a second position each of which allows the passage of gas from the pneumatic gas source through the first pilot valve and to the pneumatic motor, thereby actuating the motor and moving the door.