Device to display undr pressure in a filter element

摘要

A pressure display assembly indicates the suction pressure on the outlet face of an air filter incorporated in an internal combustion engine. The assembly consists of a housing (1) enclosing a movable piston (16) which separates the low pressure zone from the ambient pressure. The novelty is that the piston moves a spring by snap-fitting action on an electrical contact following a defined redn. in pressure.