Uniform turnover mechanism and method for controlling the same

1. A uniform turnover apparatus comprising a turnover body, a linear advance device, and a fixed base, the linear advance device having a fixed end and a movable end, the fixed end being turnably provided on the fixed base by a first fulcrum, the turnover body being movably connected with the movable end of the linear advance device by a second fulcrum, the turnover body being turnably provided on the fixed base by a third fulcrum, the first, the second, and the third fulcra forming a triangle, wherein the uniform turnover apparatus further comprises a control device which is connected with the linear advance device, the control device acquiring an actual angular velocity at which the turnover body is turned and comparing the actual angular velocity with a set angular velocity, and according to the comparison, adjusting in real time the linear velocity of the linear advance device, such that the actual angular velocity of the turnover body approximates or equals to the set angular velocity.

2. The uniform turnover apparatus of claim 1 , wherein said third fulcrum is a turnover shaft which is fixed to the turnover body, a trigger body being further fixed on the turnover shaft, a first travel switch and a second travel switch being fixed on the first base, both the first travel switch and the second travel switch being positioned on the turning over trajectory of the trigger body.

3. The uniform turnover apparatus of claim 2 , wherein said control device comprises an angle monitoring device for providing real time feedback of an angular position of the turnover body.

4. The uniform turnover apparatus of claim 3 , wherein said trigger body is a cam, the angle monitoring device is a potentiometer, and the linear advance device is a linear push-rod motor.

5. The uniform turnover apparatus of claim 4 , further comprising a third turnover shaft, on which is further fixed a first gear which is engaged with a second gear, wherein said second gear is synchronously rotated with the potentiometer.

6. The uniform turnover apparatus of claim 1 , wherein said turnover body comprises a detector for an X-ray photographic system and a connecting plate fixed thereto, the second and the third fulcra being connected with the connecting plate.

7. A method for controlling a uniform turnover apparatus comprising a turnover body, a linear advance device, and a fixed base, the linear advance device having a fixed end and a movable end, the fixed end being turnably provided on the fixed base by a first fulcrum, the turnover body being movably connected with the movable end of the linear advance device by a second fulcrum, the turnover body being turnably provided on the fixed base by a third fulcrum, the first, the second, and the third fulcra forming a triangle, the method comprising the steps of:

(1) monitoring angular position information of the turnover body and calculating an actual angular velocity of the turnover body according to the angular position;

(2) comparing the actual angular velocity of the turnover body and a set angular velocity;

(3) controlling the linear advance device to reduce linear velocity thereof if the actual angular velocity is larger than the set angular velocity; controlling the linear advance device to increase the linear velocity thereof if the actual angular velocity is smaller than the set angular velocity.

8. The method for controlling a uniform turnover apparatus of claim 7 , wherein, in step (1), the angular position information of the turnover body is monitored by a potentiometer in real time.

9. The method for controlling a uniform turnover apparatus of claim 7 , wherein said linear advance device is a linear push-rod motor.

10. The method controlling a uniform turnover apparatus of claim 9 , wherein in step (3), the linear velocity of the linear push-rod motor is changed by adjusting the duty ratio of the driving signal of the linear push-rod motor.