Device preferably for driers for compressed air

Claim 1

An air controller for use in a compressed air producing plant including an air compressor and a compressed air drying device disposed downstream of the compressor and including two containers each filled with water absorbing, air permeable charge, the containers being arranged in parallel relative to each other and each having an inlet adapted to communicate with a pressure side of said compressor, and an outlet adapted to communicate with further sections of the plant, the outlets being interconnected by a shunt pipe having a reduced rate of flow relative to the rate of flow through any of the respective outlets of the containers, the controller effecting alternate purge of the charge in the containers by a countercurrent passage of dried air through one of said containers to remove water accumulated therein, said controller comprising a housing including an inlet port adapted to communicate with a source of wet pressurized air, a first outlet port and a second outlet port, each of said outlet ports being adapted to communicate with a first and second one of said containers, and a venting port communicating with free atmosphere, the controller further comprising: (a) said inlet port communicating with said outlet ports through a first and a second duct in the housing, said ducts each having an upstream and communicating with a first valve chamber through a respective valve seat, a flip-flop valve member being disposed within said first valve chamber for alternate engagement with one of said valve seats; (b) said first and second ducts communicating with each other through a second valve chamber having two valve seats, one at each end of the chamber communicating with the respective duct; (c) a second valve member arranged for alternately engaging one of the two valve seats of the second valve chamber; (d) a valve member retainer means provided in said housing and including spring means for resiliently urging said second valve member into engagement with the respective one of said valve seats of the second valve chamber, said retainer means including release means allowing free displacement of said second valve member from one of the second valve chamber seats to the other on displacement of said retainer means against the force of said spring means; (e) said second valve chamber including a vent passage communicating between the second valve chamber and said venting port, said vent passage being operatively associated with a vent shut-off means adapted to interrupt the communication between the second valve chamber and the venting port on displacement of the retainer means against the force of the spring means; and, (f) power means for inducing displacement of said retainer means against the force of said spring means.