US Patent 7786392 Self-cleaning pressure switch with a self-sealing diaphragm

An improved pressure switch comprises a cover assembly, a pair of electrical terminals, a spring, a contact disk, a diaphragm and a banjo housing. The pair of electrical terminals can be partially covered by the cover assembly and the spring can be placed within the cover assembly. The contact disk can tightly be connected with the diaphragm and arranged on top of the spring. When the pressure exceeds a preset pressure level, the diaphragm can be deflected down onto the contact disk, which compresses the spring to contact the terminals. The terminals can be activated for energizing, for example, a hydraulic circuit if the contact disk contacts the terminals. Therefore, the disk can bias itself when the disk makes contact on the top of the terminals, which creates a movement of the disk to provide a self cleaning feature.