Pressure cooker with bayonet type lid fixing - prevents excessive pressure by allowing local deflection of sealing ring

摘要

The pressure cooker has a cylindrical body (1) with a domed lid (5) which is retained by means of lugs (7) which are pushed through cut-outs (3) in the flange (2) so that when the lid (5) is rotated the lugs (7) fit underneath the flange (2). A U-shaped seal (12) has lips (14, 15) which are pressed against the body and lid respectively by the steam pressure. Two diametrically opposite holes (11) are in the vertical surface (6) of the lid. If the steam pressure rises to an excessive value the seal (12) is deffected locally into the hole (11), pushing the cut-out (20) in the lip (14) over the cut-out (3) in teh flange (2) permitting the escape of steam and reducing the pressure.