A processing line for laminar material, comprising:
- a first processing plant;
- a second processing plant, which is placed downstream of said first processing plant and is suitable to process workpieces in output from said first processing plant;
- and
- a conveyor belt that is placed between said first processing plant and said second processing plant for transferring workpieces in output from said first processing plant to an input of said second processing plant,
- wherein said second processing plant is configured to require that in predefined operational phases of processing said input be disengaged by said conveyor belt,
- wherein said conveyor belt comprises a support structure;
- a mobile belt which is supported by said support structure and extends between a first end and a second end along a movement direction to form a transport plane;
- a plurality of rollers that are associated to said support structure and are suitable to support and move said mobile belt along a closed path, said plurality of rollers comprising a drive roller and at least one idler roller, wherein said plurality of rollers comprises two further idler rollers, wherein:
- two first rollers of said plurality of rollers are placed at a same height (Hi), wherein one first roller is placed at said first end and the other first roller is placed at said second end so as to impose on the mobile belt a horizontal section (P1) in said closed path, the horizontal section (P1) defining said transport plane;
- and two second rollers of said plurality of rollers are placed in proximity of said second end lower than the two first rollers, said two second rollers being staggered both horizontally and in height respectively at an intermediate height (H2) and at a lower height (H3), so as to impose on the mobile belt—in cooperation with the other first roller arranged at the second end a double S-shaped section (P2) in the closed path, said closed path being completed by an inclined section (P3) connecting the double S-shaped section (P2) to the horizontal section (P1) at the one first roller placed at the first end, wherein the one first roller placed at the first end and the one of the two second rollers placed at said lower height (H3) are rotationally supported directly by said support structure in fixed positions, while the other first roller placed at the second end and the one of the two second rollers placed at said intermediate height (H2) are rotationally supported by a mobile frame which is slidingly associated to said support structure to be moved between a retracted position, in which the other first roller placed at said second end is positioned completely inside said support structure, and an extracted position, in which the other first roller placed at said second end protrudes outside said support structure, wherein, while transitioning between said retracted position and said extracted position, a length of said horizontal section (P1) varies and is compensated by an equivalent variation in length of the double S-shaped section (P2), due to the fact that the one of the two second rollers placed at said intermediate height (H2) integrally follows movements of the other first roller placed at the second end;
- and—support means suitable for supporting said mobile belt underneath the horizontal section (P1) of said closed path, said support means comprising at least one fixed plate directly associated to said support structure and at least one mobile plate integral with said mobile frame, wherein said at least one fixed plate and said at least one mobile plate are placed on staggered planes underneath and parallel to the transport plane defined by the mobile belt at the horizontal section (P1),
- and wherein said conveyor belt is placed in a fixed position between said first processing plant and said second processing plant and is oriented in such a way that said mobile belt has its second end placed at the input of said second processing plant when said mobile frame is in said extracted position and in such a way that said mobile belt can disengage said input when said mobile frame is in said retracted position.