Patent ID: 7086841

Claim:
An automatic inlet control mechanism for connection to a compression cylinder inlet of a reciprocating air compressor unit which produces compressed air at a predetermined rate of production through the use of a piston that reciprocates within a compression cylinder, said inlet control mechanism comprising: a mechanism body having a valve cavity, said valve cavity having a valve control chamber and a valve inlet chamber, a valve piston assembly positioned between said valve control chamber and said valve inlet chamber and constructed to prevent air flow between said valve control chamber and said valve inlet chamber; a valve inlet positioned to allow air to flow from the atmosphere surrounding the compressor unit and into said valve inlet chamber; a valve outlet having a valve outlet hole positioned to allow air to flow from said valve inlet chamber to the compression cylinder inlet, said valve outlet hole having a size sufficient to enable the compressor unit to produce compressed air at its predetermined rate of production; said valve piston assembly including a valve piston, said valve piston assembly being positioned to reciprocate within said valve cavity, a biasing member having a force which moves said valve piston assembly to a position within said inlet control mechanism which prevents air from flowing from said valve inlet chamber through said valve outlet when the compressor unit is not drawing air through said valve outlet; a vent passageway allowing air to flow between said valve control chamber and the compression cylinder inlet; said vent passageway comprising at least one source of air to the compression cylinder inlet for a period of time after the compressor unit begins to draw air through the compression cylinder inlet, following the movement of said valve piston assembly to a position which prevents air from flowing from said valve inlet chamber through said valve outlet; said vent passageway including a vent orifice which restricts the flow of air from said valve control chamber to said compression cylinder inlet; and said vent orifice having an orifice size which allows air to be drawn, by the compressor unit, from said valve control chamber to the compression cylinder at a preselected rate which causes the compressor unit to produce compressed air at less than its predetermined rate of production, said valve control chamber having a volume which enables air to be drawn through said orifice from said valve control chamber by the compressor unit over a preselected time period until air within said valve control chamber is at a reduced pressure level which enables atmospheric pressure on said valve piston assembly from within said valve inlet chamber to overcome the force of said biasing member sufficiently to move said valve piston assembly away from the position at which said valve piston assembly prevents air from flowing from said valve inlet chamber and through said valve outlet to enable the compressor unit to produce compressed air at its predetermined rate of production.