Automotive air conditioning system including electrically operated expansion valve

An electrically operated expansion valve for use in an automotive air conditioning system comprising:

• a valve body formed with an internal bore extending into said body from one end thereof, an inlet port generally transverse to and intersecting said bore, and an outlet port generally transverse to and intersecting said bore, said inlet and outlet ports being offset relative to each other along the major axis of said bore, with said inlet port being closer to said one end of said valve than said outlet port;
• a hollow sleeve member tightly fitted within said bore in the region of said outlet port, said sleeve member being formed with a valve seat on one end thereof and an opening through its wall to provide communication between the interior of said sleeve member and said outlet port, said sleeve member being further formed with an exterior channel extending the length of said sleeve member substantially opposite said opening;
• a solenoid mounted on said one end of said valve body, said solenoid having a movable plunger extending into said internal bore, the end of said plunger which extends into said internal bore being formed as a valve member to cooperate with said valve seat to control the flow through said inlet and outlet ports, energization of said solenoid causing said plunger to move outward from said valve body;
• spring means for yieldably biasing said plunger inward of said valve body;
• means for pressure balancing said valve;
• and
• means for providing at least a minimum flow through said inlet and outlet ports independent of the condition of said solenoid.