Refrigeration – With means for charging closed refrigeration producing system
Reexamination Certificate
1999-10-05
2001-03-20
Doerrler, William (Department: 3744)
Refrigeration
With means for charging closed refrigeration producing system
C062S149000
Reexamination Certificate
active
06202433
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for servicing refrigeration systems and particularly to a system which integrally includes a flow control for the sampling of refrigerant type.
When vehicles are brought to a service center for professional servicing of the air conditioning system, frequently the system has had refrigerant leaks and losses in the past and either the vehicle owner or service center that does not have the proper equipment or refrigerant has mixed different types of refrigerant or added the wrong refrigerant to the system. The preferred refrigerant now in use is the environmentally approved R-134. Still available, however, is the previously used R-12 refrigerant and R-22 refrigerant is used in home air conditioning systems. Frequently, a vehicle owner will mix the wrong types of refrigerant or purchase a blend of refrigerants from a retail store in an attempt to recharge the system, which, having needed to be recharged, leaks refrigerant and does not operate satisfactorily with the wrong or blended refrigerant. Thus, when a vehicle finally reaches a service center with proper equipment for professional maintenance of the air conditioning system, frequently refrigerant contained in the system is a mix and of an unknown nature. Thus, it is necessary and desirable to identify whether this problem exists and, if so, completely new refrigerant of the proper type is employed for charging the system.
In order to detect the refrigerant in a vehicle refrigerant circuit, a sample is taken directly from the vehicle coupled to the servicing instrument. Also, it is useful to periodically monitor the recovery tank of the system to make certain it has not become contaminated. In the past, a stand-alone flow control system has been provided which provides a metered orifice and pressure control switch to allow the sampling of refrigerant from the servicing unit to a refrigerant identification instrument, such as a Neutronics ACR2KID, through an oil separator. The oil separator protects the instrument from damage due to oil in the refrigerant being sampled from entering the instrument. The disadvantages of this prior art system is that it is an add-on, stand-alone unit requiring its own power source and is somewhat prone to incorrect installation by the service technician to protect the refrigerant identification unit. Further, this only permits testing of refrigerant on the low side (vapor) of the air conditioning servicing unit.
There remains a need, therefore, for a protection system for refrigerant identification detectors and one which is integrated with the refrigerant recovery and recharging system and one which allows sampling of refrigerant, either from the high or low pressure sides of the recovery system and also from the main refrigerant tank.
SUMMARY OF THE PRESENT INVENTION
The system and method of the present invention provides a refrigerant recovery system which evacuates and recovers refrigerant from a refrigeration circuit, such as a vehicle air conditioning system, filters and removes oil therefrom, and recharges the refrigerant to the proper pressure, adding new oil as required. Integrally included within the recovery and recharging system is a flow control system allowing for the sampling of refrigerant from a refrigerant recovery inlet of the system or, alternatively, the refrigerant recovery main tank as well as metering refrigerant selected from either source, filtering oil therefrom to provide a clean vapor refrigerant sample to the refrigerant identification detector. Oil separated from the refrigerant is returned to the oil drain of the main system for collection.
In a preferred embodiment of the invention, an orifice of about 0.016″ to 0.025″ is provided to limit the flow rate. A pressure operated sensor allows sensing of refrigerant only when the pressure is below a predetermined level, thereby protecting the oil separator and refrigerant identification detector from excessive pressures and oil blow by. Systems embodying the present invention include a first conduit having a pressure control valve coupled thereto and a check valve permitting refrigerant coupled from the refrigerant inlet to the refrigerant recovery and recharging system to a check valve, a metering orifice, an oil separator, and having an outlet for coupling to a refrigerant identification detector. The system includes a second conduit coupled to the main refrigerant recovery tank through a solenoid valve communicating also with the orifice and oil separator, with a valve being selectively operable for sampling either incoming refrigerant to the recovery and recharging system from the refrigerant circuit under service or from the recovery tank of the servicing instrument itself. A third conduit couples the collected oil from the oil separator through a check valve and control solenoid to the oil recovery system of the recovery and recharging unit.
Thus, with the system of the present invention, refrigerant can be safely sampled by either the circuit under servicing or the recovery tank of the servicing unit, protecting the refrigerant identification detector from damage due to oil blow by or excessive flow rates of refrigerant. These and other features, objects and advantages of the present invention will become apparent upon reading the following description thereof together with reference to the accompanying drawings.
REFERENCES:
patent: Re. 33212 (1990-05-01), Lower et al.
patent: 4261178 (1981-04-01), Cain
patent: 4363222 (1982-12-01), Cain
patent: 4364236 (1982-12-01), Lower et al.
patent: 4441330 (1984-04-01), Lower et al.
patent: 5127239 (1992-07-01), Manz et al.
patent: 5172562 (1992-12-01), Manz et al.
patent: 5181391 (1993-01-01), Manz
patent: 5182918 (1993-02-01), Manz et al.
patent: 5193351 (1993-03-01), Laukhuf et al.
patent: 5209077 (1993-05-01), Manz et al.
patent: 5231842 (1993-08-01), Manz et al.
patent: 5272882 (1993-12-01), Degier et al.
patent: 5335512 (1994-08-01), Hancock et al.
patent: 5517825 (1996-05-01), Manz et al.
patent: 5582023 (1996-12-01), O'Neil
patent: 5758506 (1998-06-01), Hancock et al.
patent: 6016661 (2000-01-01), Sager
patent: 6029472 (2000-09-01), Galbreath, Sr.
patent: 6119475 (2000-09-01), Murray et al.
Brown William C.
Murray Walter D.
Doerrler William
Jones Melvin
Pepper Hamilton LLP
SPX Corporation
LandOfFree
Protection system for refrigerant identification detector does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Protection system for refrigerant identification detector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Protection system for refrigerant identification detector will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2544992