Air dryer system

Claim 1

Compressed air apparatus comprising a compressor, a reservoir for storing compressed air generated by said compressor, disabling means for disabling said compressor, a governor responsive to a pressure level in the reservoir for generating a governor pressure signal causing said disabling means to disable said compressor when the pressure level in the reservoir attains a predetermined level, and a drying subsystem for drying the air communicated to said reservoir, said drying subsystem including a pair of housings having inlet ports for receiving compressed air from said compressor and having delivery ports communicated to said reservoir, each of said housings containing a desiccant material, each of said inlet ports being connected to said compressor through a shuttle valve having a shuttle movable from a first position closing off one of said inlet ports and communicating the other inlet port to the compressor to a second position closing off the other inlet port and communicating the one inlet port to the compressor, said shuttle being responsive to a pressure signal to move between said first and second portions, timing means for generating said pressure signal moving said shuttle on a periodic timed basis, first check valve means connected between the delivery ports of said housings, an orifice around said first check valve means, and second check valve means permitting communication into said reservoir from the drying subsystem but preventing communication from said reservoir into said drying subsystem.