Air compressor unloader system

Abstract

An air compressor unloader assembly for unloading the compression chamber of an air compressor during a compressor unloading cycle. The unloader assembly includes an unloader piston slidable within an unloader cylinder in the head of the compressor for slidably engaging the intake valve of the compressor and to hold the intake valve open for unloading of the compression chamber of the compressor pump. The unloading cylinder is accessible from an exterior surface of the head via a removable threaded plug in a gas tight arrangement. The plug is dimensioned whereby the unloader piston may be readily accessed for lubrication and/or removed for repair or replacement without having to remove the head from the air compressor cylinder.

1 . In a reciprocating gas compressor having a compression chamber closed off with a head and an intake valve and an exhaust valve in said head for regulated gas inlet to and gas outlet from said chamber, and a compressor unloading assembly for unloading said chamber during a compressor unloading cycle, said unloading assembly comprising: 
 an unloader piston slidable within an unloader cylinder in said head for engaging said intake valve to hold said intake valve open for unloading said compression chamber, said unloading cylinder accessible from an exterior surface of said head via a removable plug sealing said unloading cylinder gas tight, said plug dimensioned whereby said unloader piston may be readily accessed and removed for repair without having to remove said head from said compressor cylinder.    
   
   
       2 . The unloading assembly set forth in  claim 1 , including a pressure governor having an inlet connected to receive gas outlet under pressure from said compressor and having an outlet connected to said unloader cylinder for moving said unloader piston to open said intake valve with gas under pressure when a predetermined gas outlet pressure from said compressor has been attained.  
   
   
       3 . The unloading assembly set forth in  claim 2 , wherein said plug is threadably received in said head.  
   
   
       4 . The unloading assembly set forth in  claim 2 , wherein said unloader piston slides toward said compression chamber to engage and hold open said intake valve.