| 摘要 |
The invention relates to a device for reducing the clamping bar pressure exerted on a stack of a paper in a paper-cutting machine during cutting indication, in the case of which a hydraulically actuated piston/cylinder unit is provided to impart movement and pressure to the clamping bar, it being possible to limit the operating pressure of the hydraulic medium and therefore the actuating force of the clamping bar using a pressure control valve inside a pressure-generating device. The invention has such a device which is of simpler design. This is achieved in that a second pressure control valve (18) is provided which is set to a lower pressure than the first pressure control valve (16), that an electric control circuit is assigned to the actuating device for the cutting indication system and actuates the light barrier arrangement, which is provided in order to protect the operator during cutting, in such a way that the said arrangement generates a signal when the optical path is blocked, which signal causes the first pressure control valve (16) to become inactive and switches on the second pressure control valve (18). The invention causes the clamping bar to be lowered at great speed as long as the light barrier is not broken and on the other hand that the static and dynamic cutting indicator force and the lowering speed are kept low when work is being carried out beneath the clamping bar. <IMAGE> |
