Patent ID: 8123054

Claim:
A drinking cap including a first tubular portion for connection to the mouth of a beverage container and an elongate actuating member situated at least partially within the first tubular portion, the first tubular portion being connected to the actuating member by a resilient, annular, integral web, in which one or more flow openings are formed, one of the web and the internal surface of the first tubular portion, being connected to a projecting annular first sealing flange, the actuating member being longitudinally movable in the axial direction between an open position, in which the flow openings are unobstructed, and a closed position, in which the sealing flange is in sealing engagement with the other of the web and the internal surface of the first tubular portion, whereby, in use, the flow openings are prevented from communicating with the atmosphere and the container is sealed, characterised in that the cap further includes an insert and a piston which together define a reservoir, the insert including a cylindrical wall and a portion which is movable under the action of pressure within the reservoir and in which a discharge aperture is formed, the piston including a peripheral edge in sliding contact with the cylindrical wall and having an aperture, a flow tube being connected to the piston around the aperture and extending through the discharge aperture in the insert and forming a sliding seal with the edge of the discharge aperture, and that the actuating member is arranged to engage the piston when it is moved from the closed position to the open position and thus to move the piston towards the insert, whereby the increased pressure created in the reservoir causes the movable portion of the insert to move away from the piston until the flow tube moves out of the discharge aperture in the insert.