Bottle screw cap employing resilient disc seal as overpressure safety valve has radial grooves in sealing collar, permitting distortion of resilient disc seal to remove overpressure

摘要

The sealing collar (14) includes local recesses (not shown). Should excess pressure develop inside the bottle (6), the disc seal (15) is distorted. Apart from forming a dome, it curves up locally into the recesses (radial grooves across the seal) forming radial passages through which the pressure is released.