| 摘要 |
<p>The device for sensing the outer diameter of a roll of web upon unwinding of the web from the roll for the actuation of a control member when the diameter of the roll has been reduced to a predetermined minimum diameter, comprises a follower arm capable of swinging movement to-and-fro in the direction of the axis of the roll around a fixed axis and urged in the direction of the said roll axis. The swinging movement of the follower arm controls the actuation of a control member. The follower arm carries a feeler element intended to bear against the circumferential surface of the web roll, and the said feeler element is constructed as a gauging fork or snap gauge having a pair of arms which are spaced between each other of a predetermined distance, in such a manner that the clear distance or clearance between the said two arms corresponds to the predetermined minimum diameter of the roll.</p> |
