Method of adjusting the heights of the nipping belts in a transport conveyor

An adjustment method for adjusting heights of nipping belts in a transport conveyor that move flat articles in series and on edge, with a view to obtaining a transport height that is substantially constant for the flat articles while they are being moved by the nipping belts in the conveyor, said adjustment method comprising:

• causing the conveyor to operate empty in such a manner that the nipping belts of heights that are to be adjusted run without any flat article in the conveyor;
• emitting two light beams towards a belt of height that is to be adjusted, which light beams are parallel and superposed, being spaced apart by a certain distance equal to the width of the belt between the two opposite edges of the belt of height that is to be adjusted, these two light beams being emitted from a housing having a stand that is calibrated heightwise so that the two light beams are disposed relative to the stand of the housing at a certain height that is calibrated to correspond to said transport height at which the flat articles are transported in the conveyor;
• and
• manipulating a tensioner over which the nipping belt to be adjusted is engaged so as to move said belt heightwise while it is running empty until the two light beams intersect respective ones of the two opposite edges of the belt.