| 摘要 |
1. Device for manufacturing a tubular structure formed by a film of extruded synthetic material with at least partially perforated wall, and making it possible to obtain a film presenting a regular, constant thickness allowing in particular the subsequent passage of the film in a printing machine or over the shaper of a fashioning machine, of the type comprising an extrusion slot (3) associated with a circular comb (4) adapted to be moved in a reciprocating movement perpendicular to the median plane of the extrusion slot, this comb bearing teeth adapted to come into position of obturation in front of said extrusion slot in order to provoke, in manner known per se, apertures or gaps in the surface of the film, and the device is characterized in combination : a) in that the extrusion slot or die is preceded by a passage (14) in the form of a ring, of thickness identical to the height of the extrusion slot and thus adapted to regulate and adjust the thickness of the extruded film ; b) and in that the extrusion slot is defined by a circular gap between two walls of which a first cylindrical wall (30) constitutes a bearing surface of the comb (4) which slides against said wall, and a second wall constituted by an annular shoulder (31) projecting externally with respect to the virtual extension of said first cylindrical wall, with the result that the teeth of the comb are thus adapted in their movement in position of obturation in front of the die, to bear against the face of this shoulder which is perpendicular to the reciprocating movements of the teeth and parallel to the flow of the film. |
