| 摘要 |
<p>Vacuum conveyor, which is suitable for guiding a running web, e.g. paper web, in particular a lead strip or "threading tail" (e.g. during "threading" of a paper or board web into a machine for the production or finishing or processing of such a web), with the following characteristics: a) an air-pervious endless conveyor belt is tensioned over at least two rolls with a suction box being located in the loop of the conveyor belt and being connected to a source of vacuum; b) at least one of the rolls can be driven, to allow the endless conveyor belt to travel over the rolls and over the suction box, whereby the vacuum propagates through the run of the conveyor belt running in the direction of web travel, in order to draw the web to be guided onto the conveyor belt by suction; c) a vacuum control is adapted to establish a fast decrease of the vacuum degree in the suction box; d) the vacuum control comprises a movable element positioned at an inner surface of a wall of the suction box where said wall has an aperture which may be closed by said movable element; e) an actuator being connected to the movable element which actuator, in an active state, causes the closing of said aperture by said movable element. <IMAGE></p> |
