| 摘要 |
The invention relates to a pulling device for providing a smooth linear pulling movement. The device comprises a shaft (8) rotatable around its longitudinal axis, a pulling nut moving linearly on the shaft and driven by the rotational movement of the shaft and arranged to have the member to be pulled to be attached to, and a motor (9) providing the rotational movement of the shaft. The linear movement of the pulling nut is advantageously provided with the aid of pulling bearings set against the shaft (8) at a pitch angle. It is essential to the invention that the rotational movement of the motor (9) is transmitted to the shaft (8) through the intermediary of a flexible O-ring (25) between mutually nested parts (8, 22) associated with the motor and the shaft. The O-ring (25) forms between said parts (8, 22) a narrow contact surface closing a circular line, the purpose of which is to keep the rotational movement of the shaft as smooth as possible. The pulling device according to the invention is well-adapted for moving, for instance, the exposed sliding plate pulled out of the RIM cassette used in X-ray photography during the reading of the information on the plate and its subsequent emptying. |
