Dispensing valve having cup-like deformable sealing element

Claim 1

IN A DISPENSING VALVE FOR A PRESSURIZED CONTAINER: A HOUSING MEMBER ADAPTED TO BE RECEIVED IN THE NECK PORTION OF A CONTAINER AND INCLUDING AN INNER END AND AN OUTER END; A PASSAGEWAY THROUGH SAID HOUSING BETWEEN THE INNER AND OUTER ENDS THEREOF; A STEM MEMBER MOUNTED IN SAID PASSAGEWAY FOR AXIAL MOVEMENT RELATIVE THERETO BETWEEN AN OPEN POSITION AND A CLOSED POSITION, AN UPPER PORTION OF SAID STEM MEMBER BEING OF LESSER CROSS-SECTIONAL AREA THAN AN UPPER PORTION OF SAID PASSAGEWAY TO DEFINEA TRANSFER CHAMBER THEREBETWEEN; PASSAGE MEANS AT LEAST PARTIALLY IN SAID STEM MEMBER FOR PLACING SAID TRANSFER CHAMBER IN COMMUNICATION WITH THE EXTERIOR OF THE VALVE; ONE OF SAID MEMBERS PROVIDING UPPER AND LOWER CYLINDRICAL WALL SURFACES OF PREDETERMINED DIAMETERS AT THE PASSAGEWAY, THE OTHER OF SAID MEMBERS PROVIDING UPPER AND LOWER CUP-LIKE SEALING ELEMENTS EACH WITH A LIP PORTION ADJACENT ONE OF SAID CYLINDRICAL WALL SURFACES, RESPECTIVELY, SAID CYLINDRICAL WALL SURFACES AND SAID CUP-LIKE SEALING ELEMENTS EACH BEING OF A SIZE AND BEING POSITIONED SO THAT THE UPPER LIP PORTION AND THE UPPER WALL SURFACE REMAIN IN SLIDING SEALING ENGAGEMENT WHEN THE STEM MEMBER IS IN THE CLOSED POSITION AND IN THE OPEN POSITION, AND THE LOWER LIP PORTION IS IN SEALING ENGAGEMENT WITH THE LOWER WALL SURFACE WHEN THE STEM MEMBER IS IN THE CLOSED POSITION AND IS SPACED AXIALLY THEREFROM WHEN SAID MEMBER IS IN THE OPEN POSITION, SAID STEM MEMBER AND SAID PASSAGEWAY BEING SO FORMED THAT COMMUNICATION IS ESTABLISED BETWEEN SAID TRANSFER FCHAMBER AND SAID INNER END OF SAID HOUSING MEMBER WHEN SAID STEM IS IN SAID OPEN POSITION.