Apparatus for obtaining differential tangential variable speeds at different points of a deformable film
AssigneeSociete des Etablissements Thimon
InventorsHubert Thimon, Paul Jacquier
Life of this patent
Estimating the term…
Abstract
The invention relates to a drawing device. This device is designed such that the differential tangential speeds V are variable at different points of a deformable flat film (1) or plate that moves along at least one drawing roller (3) rotating about an axis XX, said film (1) or plate moving in a direction perpendicular to the axis of rotation of the roller and resting on a generatrix G.sub.N of the roller. The roller (3) has a rotational speed N which is constant with time, while the distance G.sub.N C.sub.1 from the supporting generatrix G.sub.N of the film to the axis C.sub.1 of rotation of the roller is variable with time. The invention is applicable to the drawing of plastic films.
Claims8
An apparatus for stretching a deformable film, comprising:
- first means for drawing a deformable film, the first means including a first roller and a second roller, each roller including a plurality of longitudinally extending surface members, the surface members forming a substantially cylindrical support surface defined by a radius on the respective roller for supporting the deformable film, each surface member thus corresponding to a respective film section of the deformable film;
- a first rotating axle and a second rotating axle supported substantially parallel to said first rotating axle, said first axle rotatably supporting said first roller and said second axle rotatably supporting said second roller, each of said axles extending in the longitudinal direction of said surface members;
- second means coupled to said surface members for driving said surface members in a radial direction substantially perpendicular to the axial direction of said respective axle;
- third means coupled to said rotating axles for rotatably driving said axles and thus said surface members;
- and
- a control unit coupled to said second means to control the movement of said surface members in said radial directions and thus adjust the diameters of said cylindrical support surfaces, said control unit being adapted to adjust the diameter of said support surface of said first roller relative to the diameter of said support surface of said second roller to obtain differential speeds between the film sections supported by said first roller relative to the film sections supported by said second roller to stretch the deformable film.
Dependencies are inferred from the claim text.