Patent attributes
A liquid level assembly for controlling liquid level has a switching mechanism responsive to the liquid head to activate a pump. A housing assembly has an internal cavity in which the switching mechanism is supported, the housing assembly having an open end sealed by a diaphragm seal having a flexible planar portion that transmits head pressure to the switching mechanism. The diaphragm seal also has a peripheral web portion and a flexible bellows portion connecting the flexible planar portion and the peripheral web portion. The peripheral web portion has a peripheral sealing bead that is sealingly compressed against a groove in the housing assembly, and a plurality of knob members extend from the peripheral web to press against the switching assembly, thereby accommodating manufacturing dimensional tolerances of the switching mechanism.