Patent ID: 7859203

Claim:
A delay unit for door with a door closer comprising: a first sensor for detecting that the door with a door closer has been opened to the first certain angle; an electrical lock/unlock means for electrically locking/unlocking the rotation of the rotation axis of the door; a timer; a control means which is connected with the first sensor, electric electrical lock/unlock means, and timer and controls the electrical lock/unlock means on the basis of the signals from the first sensor and timer; wherein when the door has been opened to the first certain angle, the electrical lock/unlock means locks the rotation of the rotation axis of the door, and the control means controls the timer to start based on the detection signal from the first sensor; after the elapse of the first certain time, on the basis of the signal from the timer, the control means sends a control signal to the electrical lock/unlock means, thereby releasing the rotation lock of the rotation axis of the door by means of the electrical lock/unlock means.