Abstract: A tire inflation valve stem comprises a stationary, radially outer stem part (3); a movable, radially inner stem part (4) slidable axially within the outer part; a compression reaction spring (20) extending between the core parts; and a flexible barrier (23) extending from one core part to the other to prevent air leakage between the parts. The flexible barrier comprises a thin walled, soft elastomeric tube sealed at its ends to the respective core parts and with an intermediate part curved back on itself in a free rolling manner within a variable length annular space between an external cylindrical surface (19) of the movable core part and an internal cylindrical surface (12) of the stationary part.

Abstract: A homogeneous self energizing seal comprising an annular member having side walls, a top and a bottom forming the trunk of the seal, the side walls are provided with chamfered upper portions the upper edges of which merges into flat portions on the top of the seal, the bottom edges of the chamfered portions forming the sealing lips of the seal. The flat portions on the top of the seal merge into annular slots or troughs in the top of the seal which has a raised center portion upstanding therefrom.