Patent ID: 7913504

Claim:
A refrigerant expansion assembly for use in a vehicle air conditioning system comprising: an orifice inlet port configured to receive a refrigerant from a condenser; an orifice outlet port configured to send the refrigerant to an evaporator; an orifice channel connecting the orifice inlet port to the orifice outlet port and including a valve seat; a variable orifice assembly, mounted in the orifice channel, including a variable orifice body axially slidable in the orifice channel in a direction parallel to the orifice channel, the variable orifice body including a sealing flange sealingly engageable with the valve seat, an upstream variable orifice passage extending upstream from the sealing flange, a downstream variable orifice passage extending downstream from the sealing flange and a fixed orifice passage extending axially through the variable orifice body, the variable orifice assembly including an orifice spring configured to bias the sealing flange in a direction parallel to the orifice channel into engagement with the valve seat; an upstream bypass channel extending from the orifice channel upstream from the variable orifice assembly and including a ball seat; a downstream bypass channel extending from the orifice channel downstream from the valve seat; a bypass chamber connecting the upstream bypass channel to the downstream bypass channel; a check ball mounted in the bypass chamber and sealingly engageable with the ball seat; and a bypass spring operatively engaging the check ball to bias the check ball into sealing engagement with the ball seat.