Patent ID: 7913503

Claim:
A refrigerant expansion assembly for use in a vehicle air conditioning system configured for refrigerant flow in a direction of adiabatic expansion comprising: a main body including an orifice inlet port, an orifice outlet port, an orifice channel extending between the orifice inlet port and the orifice outlet port and including a fixed orifice, an upstream bypass channel extending at a non-parallel angle from the orifice channel between the orifice inlet port and the fixed orifice and including a ball valve seat, and a downstream bypass channel extending at a non-parallel angle from the orifice channel between the fixed orifice and the orifice outlet port, the upstream bypass channel connecting to the orifice channel upstream of the fixed orifice in a refrigerant flow direction of adiabatic expansion; a bypass valve flange extending from the main body and forming a bypass chamber therein, the bypass chamber connected to the upstream bypass channel and the downstream bypass channel, with the ball valve seat adjacent to the bypass chamber; a check ball mounted in the bypass chamber adjacent to the ball valve seat, the ball valve seat and check ball configured to completely prevent all refrigerant flow in a direction opposite to the direction of refrigerant flow for adiabatic expansion for all expansion assembly operating conditions; and a spring operatively engaging the check ball to bias the check ball into the ball valve seat, whereby when a refrigerant pressure in the upstream bypass channel exceeds a first predetermined pressure threshold, the check ball is moved away from the ball valve seat against the bias of the spring allowing for refrigerant flow through the upstream and downstream bypass channels in the same direction of flow as refrigerant flow for adiabatic expansion.