Abstract: A drinking device including a body having an open end and for containing a liquid, and a lid for sealingly closing the open end of the body. The lid has an outlet incorporating a first one-way valve for dispensing liquid from the body upon the application of suction at the outlet and an inlet incorporating a second one-way valve for air intake to automatically balance the internal pressure within the body with external pressure outside the body while liquid is being dispensed. The first valve includes a chamber having a resiliently deformable wall including a hole in communication with the outlet. The hole is normally closed by being pressed against an internal surface of the body by the resilience of the wall and is openable upon the application of suction.

Abstract: A drinking device including a body having an open end and for containing a liquid, and a lid for sealingly closing the open end of the body. The lid has an outlet incorporating a first one-way valve for dispensing liquid from the body upon the application of suction at the outlet and an inlet incorporating a second one-way valve for air intake to automatically balance the internal pressure within the body with external pressure outside the body while liquid is being dispensed. The first valve includes a chamber having a resiliently deformable wall including a hole in communication with the outlet. The hole is normally closed by being pressed against an internal surface of the body by the resilience of the wall and is openable upon the application of suction.