Hydraulics filter condition indicator - responding to filter medium soiling while ignoring extraneous effects

摘要

Response to press. level across filter above normal due to soiling filter medium, suppresses sudden surges in system by providing the press, transmitting rod to the appts. with a hydraulic damper, and arranging a degree of lost motion. When this is taken up, rod actuates a bellow shaped container filled with a material, which is solid below hydraulic system fluid working temp., and liq. above it. The bellows being so confined between its cylindrical, hydraulic fluid immersed housing and hat shaped cover, that only unidirectional movement from its lower to its upper surface is possible, blocks response, until hydraulic fluid is at working temp. Upper bellows surface transmits press. via a press. only responding socket/indicator pin bearing located within hat shaped cover, spring-loaded to move in proportion to the press. across the filter. Indicator pin position attained is fixed against shock-, or accelerating effects by spring loaded friction element, serving also to pre-set it as desired.