Method for automatically positioning ramps in a preform heating station

A method for automatically positioning ramps (54) in a station (10) for heating preforms (12) of a facility for manufacturing containers from preforms (12) made from a thermoplastic material, each preform (12) having a neck (16) and, directly below the neck (16), an under-neck section (21) with an outer diameter referred to as the “under-neck diameter (D1)”, the heating station (10) comprising:

• at least one pair of longitudinal ramps (54) that define a slot (56) for the preforms (12) to travel through, at least one of the at least one pair of longitudinal ramps (54) being transversely movable in order to vary a width of the slot (56);
• at least one motorized device (58A) for transversely moving the at least one transversely movable ramp of the at least one pair of longitudinal ramps (54) in order to adapt the width of the slot (56), said at least one motorized device (58A) being automatically controlled by an electronic control unit (60);
• the method comprising, during a change of format of preforms (12):
• an acquisition step (E1) of acquiring an image of at least part of each preform (12) taken by means of an image capturing device (78);
• a step (E2) of automatically determining the under-neck diameter (D1) of each preform by computer processing of said image;
• a step (E4) of automatically adjusting the width of the slot (56) by moving the at least one transversely movable ramp of the at least one pair of longitudinal ramps (54) as a function of the under-neck diameter (D1) determined during the step (E2) of determining the under-neck diameter in order to adapt the width of the slot (56) to a passage width equal to the under-neck diameter (D1) plus a predetermined transverse clearance (j).