Apparatus for adjusting the mutual distances of several elements arranged side by side, particularly pairs of blades for the straight-line cutting of sheet material

In an apparatus for adjusting and maintaining the mutual distances between a first movable element and a second movable element wherein each of said movable elements is connected to a drive means therefor, each of said drive means, in turn, is connected to a control unit, the improvement wherein said control unit comprises measuring means for measuring the distance said first element is moved by said first drive means, said measuring means operable to generate a signal and feed the same to a distance travel regulating means, said distance travel regulating means connected to said second drive means whereby said second element is moved, in transpositioning direction, precisely the same distance that said first element is moved, wherien said first element has a first sensor responsive to a fixed stop position, said second element has a second sensor responsive to said first element, each of said sensors connected to said control unit and to feed a signal thereto, each of said drive means is provided with a reverse phase, said control unit includes a first reversing means for reversing the direction of travel of said drive means and controlling the distance by which said drive means moves in response to a predetermined value, a second reversing means attached to said second sensor and to said second drive means and responsive to the position of said first element, whereby when said second sensor is activated it generates a signal in said control unit activating said second reversing means whereby the travel of said second element is reversed, first reposition measuring means which determines the distance by which said first element moves from said fixed stop position to its new position of predetermined value, and second reposition measuring means connected to said second reversing means, said second reposition measuring means connected to and responsive to the signal of said first reposition measuring means whereby to limit the reverse travel of said second element from the first element's new position so that it is precisely the distance between said fixed stop position and said new position.