| 摘要 |
Device for opening and closing the delivery opening (7) of a container (6) of sheet material, in which the delivery opening is initially sealed by a film (7a) of perforatable material, comprising a tubular base sleeve (1) which is open at both extremities (2a, 2b) and attached in a leaktight way by one extremity (2a) to the wall (5) of the container (6) around the delivery opening (7) in axial alignment therewith, a cap (8) with an end wall (9) and a tubular skirt (10) coaxially positioned on the said sleeve (1) and engaging therewith through threaded means (3, 11) in-between to open and close the free extremity (2b) of the said base sleeve, together with means to tear the said film at the time of the first opening operation. In the said end wall (9) of the cap (8) the device comprises a portion (14a) provided with a cylindrical piston member (14) which extends coaxially towards the said base sleeve (1) terminating within the same in a free circular edge. Piston member (14) is provided with a plurality of cutting members (16) located on at least part of the free circular edge facing the film sealing the delivery opening (7). The said piston member (14) can be moved axially with respect to the skirt (10) of the cap between a raised position in which the cutting members (16) do not engage the said sealing film and a lowered position in which the cutting members (16) lie beneath the plane of the film (7a) after tearing it. |
