| 摘要 |
A drinking cap includes a first tubular portion (10) for connection to the mouth of a beverage container and an elongate actuating member (26) situated at least partly within the first tubular portion (10) and connected to it by a resilient, annular, integral web (12), in which one or more flow openings (28) are formed. The actuating member (26) is longitudinally movable in the axial direction between an open position of the flow openings (28) and a closed position thereof. The cap also includes an insert (6) and a piston (4) which together define a reservoir (56). The insert (6) includes a cylindrical wall (34) and a portion (40) which is movable under the action of pressure within the reservoir and in which a discharge aperture (44) is formed. A flow tube (52) is connected to the piston (4) around an aperture (50) and extends through the discharge aperture (44) in the insert (6) and forms a sliding seal with the edge (46) of the discharge aperture. The actuating member (26) is arranged to engage the piston (4) when it is moved from the closed position to the open position and thus to move the piston (4) towards the insert (6), whereby the increased pressure created in the reservoir (56) causes the movable portion (4) of the insert (6) to move away from the piston (4) until the flow tube (52) moves out of the discharge aperture (44) in the insert (6). |
