Automatic expansion valve, in line, piloted

Claim 2

Refrigerating apparatus for an automobile air conditioning system including an evaporator with an inlet and an outlet, a compressor with its inlet fluidly connected to said evaporator outlet and its outlet fluidly connected to the inlet of a condenser, an expansion valve assembly including a tubular housing with an inlet fluidly connected to the condenser and an outlet fluidly connected to the inlet of said evaporator to provide a refrigerant flow passage from said condenser tO said evaporator, said tubular housing enclosing a valve housing between said inlet and outlet, said valve housing forming a control chamber and a piston cylinder, a sealed casing within said control chamber having opposite end portions joined by a corrugated side surface for relative movement of said end portions in response to pressure changes within said control chamber, one end portion fixedly connected to said valve housing, a pilot valve passage spaced from the other end portion and extending between said control chamber and said expansion valve inlet, a pilot valve assembly including a valve member closing said pilot valve passage and a valve rod operably connected to the other end portion of said casing to cause the valve rod to contact said pilot valve member and open said pilot valve passage in response to a decrease of pressure within said control chamber, a piston valve mounted for reciprocation in said piston cylinder and exposed on one face to evaporator inlet pressure and exposed on an opposite face to control chamber pressure, said piston valve and said valve housing having slots in their respective walls adapted to align to form a flow passage between said valve inlet and outlet when opposing forces upon the faces of said piston valve move said valve to an open position to admit refrigerant to said evaporator, whereby when evaporator inlet pressure decreases below a predetermined level, the piston valve is moved by a control chamber pressure force to a more open position to admit more refrigerant to said evaporator and resultantly increase its pressure.

Claim 3

Refrigerating apparatus for an automobile air conditioning system including an evaporator with an inlet and an outlet, a compressor with its inlet fluidly connected to said evaporator outlet and its outlet fluidly connected to the inlet of a condenser, an expansion valve assembly including a tubular housing with an inlet end fluidly connected to the condenser and an outlet end fluidly connected to the inlet of said evaporator to provide a refrigerant flow passage from said condenser to said evaporator, said tubular housing enclosing a valve housing between said inlet and outlet, said valve housing forming a control chamber and a piston cylinder, a sealed casing within said control chamber having opposite end portions joined by a corrugated side surface for relative movement of said end portions in response to pressure changes within said control chamber, one end portion fixedly connected to said valve housing, a pilot valve passage spaced from the other end portion of said bellows and extending between said control chamber and said expansion valve inlet, a pilot valve assembly including a valve member closing said pilot valve passage and exposed to refrigerant pressure from said condenser outlet for producing a closing force thereon, a valve rod operably connected to the other end portion of said casing and extending through said pilot valve passage to cause the valve rod to contact said pilot valve member and open said passage in response to a decrease of pressure within said control chamber, a piston valve mounted for reciprocation in said piston cylinder and exposed on one face to evaporator inlet pressure and exposed on an opposite face to control chamber pressure, said piston valve and said valve housing having slots in their respective walls adapted to align to form a flow passage between said valve inlet and outlet when opposing forces upon the faces of said piston valve move said valve to an open position to admit refrigerant to said evaporator, whereby as condenser outlet pressure increases corresponding to operation of the refrigerating apparatus in higher ambient temperatures, the control pressure within said control chamber will be reduced by the increased closing force on said pilot valve member which will cause a decrease in evaporator inlet pressure for a given position of said reciprocal piston valve.

Claim 4

Refrigerating apparatus for an automobile air conditioning system including an evaporator with an inlet and an outlet, a compressor with its inlet fluidly connected to said evaporator outlet and its outlet fluidly connected to the inlet of a condenser, an expansion valve assembly including a tubular housing with an inlet end fluidly connected to the condenser and an outlet end fluidly connected to the inlet of said evaporator to provide a refrigerant flow passage from said condenser to said evaporator, said tubular housing enclosing a valve housing between said inlet and outlet, said valve housing forming a control chamber and a piston cylinder, a sealed casing within said control chamber having opposite end portions joined by a corrugated side surface for relative movement of said end portions in response to pressure changes within said control chamber, one end portion fixedly connected to said valve housing, a pilot valve passage spaced from the other end portion of said bellows and extending between said control chamber and said expansion valve inlet, a pilot valve assembly including a valve member closing said pilot valve passage and exposed to refrigerant pressure from said condenser outlet for producing a closing force thereon, a valve rod operably connected to the other end portion of said casing and extending through said pilot valve passage to cause the valve rod to contact said pilot valve member and open said passage in response to a decrease of pressure within said control chamber, a piston valve mounted for reciprocation in said piston cylinder and exposed on one face to evaporator inlet pressure and exposed on an opposite face to control chamber pressure, said piston valve and said valve housing having slots in their respective walls adapted to align to form a flow passage between said valve inlet and outlet when opposing forces upon the faces of said piston valve move said valve to an open position to admit refrigerant to said evaporator, whereby as condenser outlet pressure increases corresponding to operation of the refrigerating apparatus in higher ambient temperatures, the control pressure within said control chamber will be reduced by the increased closing force on said pilot valve member which will cause a decrease in evaporator inlet pressure for a given position of said reciprocal piston valve.

Claim 5

Refrigerating apparatus for an automobile air conditioning system includiNg an evaporator with an inlet and an outlet, a compressor with its inlet fluidly connected to said evaporator outlet and its outlet fluidly connected to the inlet of a condenser, an expansion valve assembly including a tubular housing with an inlet end fluidly connected to the condenser and an outlet end fluidly connected to the inlet of said evaporator to provide a refrigerant flow passage from said condenser to said evaporator, said tubular housing enclosing a valve housing between said inlet and outlet, said valve housing forming a control chamber and a piston cylinder, a sealed casing within said control chamber having opposite end portions joined by a corrugated side surface for relative movement of said end portions in response to pressure changes within said control chamber, one end portion fixedly connected to said valve housing, a pilot valve passage spaced from the other end portion of said bellows and extending between said control chamber and said expansion valve inlet, a pilot valve assembly including a spherical valve member closing said pilot valve passage and exposed to refrigerant pressure in said expansion valve inlet from said condenser for producing a closing force upon said spherical valve member, a valve rod operably connected to the other end portion of said casing and extending through said pilot valve passage to cause the valve rod to contact said spherical valve member and open said passage in response to a decrease in pressure within said control chamber, a piston valve mounted for reciprocation in said piston cylinder and exposed on one face to evaporator inlet pressure and exposed on an opposite face to control chamber pressure, said piston valve and said valve housing having slots in their respective walls adapted to align to form a flow passage between said valve inlet and outlet when opposing forces upon the faces of said piston valve move said valve to an open position to admit refrigerant to said evaporator, whereby as condenser outlet pressure increases corresponding to operation of the refrigerating apparatus in higher ambient temperatures the control pressure within said control chamber will be reduced by the increased closing force on said pilot valve member which will cause a decrease in evaporator inlet pressure for a given position of said reciprocal piston valve.

Claim 6

Refrigerating apparatus for an automobile air conditioning system includiNg an evaporator with an inlet and an outlet, a compressor with its inlet fluidly connected to said evaporator outlet and its outlet fluidly connected to the inlet of a condenser, an expansion valve assembly including a tubular housing with an inlet end fluidly connected to the condenser and an outlet end fluidly connected to the inlet of said evaporator to provide a refrigerant flow passage from said condenser to said evaporator, said tubular housing enclosing a valve housing between said inlet and outlet, said valve housing forming a control chamber and a piston cylinder, a sealed casing within said control chamber having opposite end portions joined by a corrugated side surface for relative movement of said end portions in response to pressure changes within said control chamber, one end portion fixedly connected to said valve housing, a pilot valve passage spaced from the other end portion of said bellows and extending between said control chamber and said expansion valve inlet, a pilot valve assembly including a spherical valve member closing said pilot valve passage and exposed to refrigerant pressure in said expansion valve inlet from said condenser for producing a closing force upon said spherical valve member, a valve rod operably connected to the other end portion of said casing and extending through said pilot valve passage to cause the valve rod to contact said spherical valve member and open said passage in response to a decrease in pressure within said control chamber, a piston valve mounted for reciprocation in said piston cylinder and exposed on one face to evaporator inlet pressure and exposed on an opposite face to control chamber pressure, said piston valve and said valve housing having slots in their respective walls adapted to align to form a flow passage between said valve inlet and outlet when opposing forces upon the faces of said piston valve move said valve to an open position to admit refrigerant to said evaporator, whereby as condenser outlet pressure increases corresponding to operation of the refrigerating apparatus in higher ambient temperatures the control pressure within said control chamber will be reduced by the increased closing force on said pilot valve member which will cause a decrease in evaporator inlet pressure for a given position of said reciprocal piston valve.