Patent ID: 6161417
Filing Date: 2000-12-19
Classification: B01D,F02M

Abstract:
A restriction indicator for an air cleaner system of an internal combustion engine, the indicator comprising:(a) a housing aligned along a housing axis, the housing including a main portion having high and low pressure chambers, the high pressure chamber being in communication with atmosphere through an inlet and the low pressure chamber being in communication with an outlet passage, the outlet passage being formed through a housing extension that projects outward from the main portion of the housing along the housing axis;(b) a diaphragm that divides the housing into the high and low pressure chambers, the diaphragm being moveable relative to the housing along the housing between expanded and retracted positions, the diaphragm moving between the expanded and retracted positions in response to pressure differences between the chambers;(c) a signal member for visually indicating when the diaphragm is in the expanded and retracted positions, the signal member being positioned within the main portion of the housing and being at least partially visible through the housing, the signal member being moveable along the housing axis in concert with the diaphragm;(d) a spring positioned in the low pressure chamber, the spring having a first end that engages the signal member thereby causing the diaphragm to be biased toward the retracted position;(e) a calibration member including an elongated shaft and a spring support that projects transversely outward from the shaft, the spring support being configured to support a second end of the spring, the shaft being positioned within the outlet passage of the housing extension and the spring support being located within the low pressure chamber, the spring support having a radial dimension that is larger than a corresponding radial dimension of the outlet passage such that the spring support can not pass through the housing extension, and the calibration member being constructed and arranged to permit calibration of the restriction indicator by moving the calibration member along the housing axis to vary a biasing force of the spring against the signal member; and(f) the housing extension forming a connector for connecting the restriction indicator to the air cleaner system of the internal combustion engine.