| 摘要 |
Grippers for drawing and cutting plotters in order to advance by sections the material webs which are to be processed in segments, whereby the material web advance unit used is in the form of the programme-controlled forward- and rearward-driven transverse carrier (1) for the processing head (2) and of a gripper fixed to the transverse carrier (1). According to known solutions, use is made of terminally-located clamps which grip the edge of the material web; it is, furthermore known to pierce the paper web with a pin-carrying unit and to apply suction to the paper web in order to prevent the fall of the pins which pull the paper web on the pin-carrying unit. According to the invention, in order to ensure the trouble-free and highly-precise feed of the material web, the transverse carrier (1) is provided with a gripper, in the form of a suction beam (6), which in particular can be lowered by means of vacuum cylinders (7) on to the material web, said cylinders extending over the entire working surface (5) of the plotter, the suction zone of which beam, on its underside, is capable of being switched off in sections in order to couple material webs of different widths. Specially-designed suction pads prevent any tendency to distortion of thin and flexible material webs during suction and transport. The accuracy of material web advance is determined only by the dimensional resolution of the plotter. |
