Governor with stabilizing means

Claim 1

In an engine governor for maintaining a desired engine speed and having a fuel control member for regulating the flow of fuel to an engine, flyweight means for controlling the movement of said fuel control member to poSition said fuel control member to increase the flow of fuel in response to an increase in engine load, main spring means mounted adjacent to said flyweight means for assisting movement of said fuel control member in a direction to increase flow of fuel, said main spring means having a spring rate, wherein said main spring means comprises a main spring, said governor including a spring seat for said main spring, said flyweight means comprising flyweights for compressing said main spring by said spring seat as engine speed increases, and means for temporarily, effectively changing said spring rate of said main spring means when engine load is suddenly increased or decreased, and thereby maintaining governor stability, said means for changing comprising a damping spring and a hydraulically damped piston for providing a force which subtracts from the force of the main spring during a decrease in engine speed and adds to the force of the main spring during an increase in engine speed, further including a hydraulically damped piston reciprocable within said bore, and said damping spring being fixed to said piston at one end thereof and to said spring seat at the other end thereof, wherein said piston and said bore form a generally cylindrical chamber on the opposite side of said piston from said damping spring, and further including orifice means for communicating said chamber with a hydraulic fluid reservoir and for providing a controlled flow of hydraulic fluid between said chamber and said hydraulic fluid reservoir as dictated by reciprocable motion of said piston, and further including a coaxial shaft attached to said piston extending on the opposite side of said piston and stop means on said shaft for limiting movement of said shaft and thereby said piston.