Device for heating preforms provided with supporting ring

A device for heating parisons (2) made of a thermoplastic material for blow molding hollow bodies and having a body area (24), a supporting ring (3), a mouth (4), and a head area (5), comprising a conveyor means (12), a plurality of holding means (6) which are situated on the conveying means and grip the head area (5) of the parisons between the supporting ring and the mouth (4), radiant heaters (36) arranged on the path of movement of the parisons which are carried by the holding means, a shield carried by the conveying means provided for each holding means to protect the head area of each parison, which is situated between the supporting ring and the mouth, from heating each shield being formed by a cover plate (8) arranged at the level of the supporting ring (3) and having a borehole (9) that surrounds the supporting ring (3) at a small distance, thereby leaving most of the head area (5) of the parisons (2) free, and a cooling device (10) which acts on the exposed head area (5) of the parison (2), wherein each cover plate (8) is designed in the manner of a plate and is connected by at least one rod (11) to the conveyor means (12) and the cooling device (10) has at least one air blowing nozzle (39) directed at the head (5) of the parisons (2).