Abstract: A mechanical thermostatic refrigerant expansion valve assembly with an electrically operated shut-off in the inlet to the valve body. Preferably, the electrical operator is a solenoid attached to the valve body on the end opposite the mechanical thermal responsive valve actuator so as to minimize the changes in the manufacturing of an existing valve body. The solenoid armature moves a secondary valving member spring biased to shut off flow in the valve inlet.

Abstract: A solenoid operated proportional control expansion valve having a tubular armature guide of non-magnetic material disposed externally of the valve blocks with a magnetic pole piece welded on the end of the tubular guide. A plastic encapsulated coil is received over the guide. The armature guide has a flange therein which in one embodiment is welded to a second flanged tube threaded into the valve blocks. In other embodiments the guide flange is directly mechanically fastened to the valve block. A cup-shaped pole frame is received over the coil for completing the magnetic flux loop about the coil.

Abstract: A technique for quick insert connecting tubular fluid pressure conduits into spaced ports having internal seal rings in a common side of a valve or block. A plastic spring lock member with apertures coinciding with the ports is disposed over the ports. The apertures are chamfered on a common side and slotted for permitting resilient expansion. The spring lock member is retained by a cover bolted to the block with clearance apertures over the ports. Upon insertion of a conduit with an annular convolution adjacent the end, the convolution cams against the chamfer expanding the slotted aperture permitting the convolution to snap through and the conduit to be retained in the port with the periphery of the conduit end contacting the internal seal ring.

Abstract: A refrigerant expansion valve has a pressure-responsive diaphragm forming a wall of a fluid filled chamber. The diaphragm is connected to one end of an actuator rod incorporating a hollow with a closed end opposite and operative to move a valve member for controlling flow between an inlet and outlet. The actuator member has the hollow communicating with the fluid filled chamber and its external surface exposed to return refrigerant flow. Fluid communications between the hollow of the actuator member and the fluid filled chamber is restricted by an orifice in a plug in the open end of the hollow to dampen the effects of sudden temperature changes of the return flow over the hollow. Preferably, the actuator member, plug, and diaphragm are commonly clamped, sealed, and welded together.

Abstract: An automotive air conditioning system utilizing an electrically operated refrigerant expansion valve controlled by a micro-computer. The compressor clutch cut-off is controlled by a suction pressure sensor at high thermal load. At partial flow conditions of the expansion valve, representative of moderate evaporator thermal loading, the micro-computer controls compressor clutch "ON" time from an accumulated count incremented by a predetermined amount according to suction pressure change. When the accumulated count over successive signal sampling intervals reaches a predetermined maximum the clutch is cut-out based on the count which is representative of a predetermined time interval.

Abstract: A system for controlling refrigerant flow in an air conditioning system employing an electrically operated valve for controlling flow of refrigerant from the condenser to the evaporator. Separate thermistors sense the temperature of the refrigerant entering and discharging from the evaporator. A comparison of the sensed temperatures is used to modify the control signal to the valve for maintaining proper refrigerant flow to the evaporator. A control module is directly attached on the valve body to enhance heat conduction.

Abstract: A refrigeration system employing a mechanical thermal expansion valve with a self-heated thermistor sensing saturation temperature at a high pressure inlet and a second thermistor sensing saturation temperature at the evaporator outlet. A microprocessor based controller compares the sensed temperature with stored limits and provides output signals to a relay for cycling the condenser fan responsive to high side pressure and the compressor clutch responsive to the low pressure side temperature. For low pressure drop evaporators, the second thermistor may be disposed at the evaporator inlet.

Abstract: A solenoid operated refrigerant expansion valve, particularly for automotive air conditioning systems, having a center-post guided tubular armature which slides on the post to provide valving of cross-ports communicating with a hollow region in the post which communicates with the valve outlet. The tubular armature has a pair of sleeves disposed on the interior at opposite ends thereof which provide the sole sliding contact surfaces on the post for minimizing friction therebetween to reduce the tendency of the armature to seize on the post.

Abstract: A system for controlling refrigerant flow in an air conditioning system employing an electrically operated valve for controlling flow of refrigerant from the condenser to the evaporator. Separate thermistors sense the temperature of the refrigerant entering and discharging from the evaporator. A comparison of the sensed temperatures is used to modify the control signal to the valve for maintaining proper refrigerant flow to the evaporator.

Abstract: A refrigeration control system for cooling a vehicle passenger compartment having a compressor/pump for circulating refrigerant between an evaporator located for cooling the compartment air and a condenser located for ambient heat exchange. An expansion valve controls refrigerant flow from the condenser to the evaporator; and, a first thermistor senses directly the temperature of the refrigerant on the high pressure inlet side of the valve and a second thermistor senses refrigerant flow temperature on the low pressure discharge side of the valve. A microprocessor compares the first thermistor output with predetermined first upper and lower values and effects opening and closing of the compressor clutch switch for high pressure cut-off; and, a fan switch is opened and closed for energization and de-energization of a condenser cooling fan.