Car radiator cap has spring-biased insert which is moved by internal pressure in radiator to position where it cooperates with locking component to prevent cap being removed

摘要

The car radiator cap (1) has annular ridges (5) on its inner surface (7) which cooperate with similar ridges (16) on the radiator lip (2). A safety device (19, 32) prevents the cap from being removed if the internal pressure of the radiator exceeds a predetermined value. This consists of an insert (32) which is biased by a spring towards a first position and is moved by the internal pressure to a second position where it cooperates with a locking component (19) to prevent the cap being removed.