Refrigeration – Automatic control – Withdrawing or adding refrigerant from or to normally closed...
Reexamination Certificate
1999-07-22
2001-02-13
Doerrler, William (Department: 3744)
Refrigeration
Automatic control
Withdrawing or adding refrigerant from or to normally closed...
C062S077000
Reexamination Certificate
active
06185945
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to refrigerant handling systems for recycling refrigerant from and recharging refrigerant to a refrigeration unit. The invention has particular application to systems of the type designed for servicing automotive air conditioners and which include a refrigerant identifier.
Refrigerant handling systems for servicing automotive air conditioners are well known. Such systems typically can be operated to recover or remove refrigerant from an air conditioner to permit servicing of the air conditioner, to recycle the recovered refrigerant by removing various contaminants therefrom, and then to recharge the refrigerant to the air conditioner after servicing is completed. Such systems are typically connected to an automotive air conditioner by two hoses, respectively connected to the high-pressure and low-pressure sides of the air conditioner compressor. These hoses have a predetermined fixed length sufficient to permit them to reach the air conditioner when the refrigerant rehandling unit is positioned alongside the vehicle.
Several different types of refrigerants are commonly used in automotive air conditioners. It is important that these refrigerants not be contaminated by contact with one another or with other types of contaminants. Thus, identifiers are used to identify the type of refrigerant in the air conditioner and its purity level. A given refrigerant handling system is typically used with only one type of refrigerant, and the identifier determines whether the refrigerant being recovered from the vehicle is of the proper type and purity.
However, in such prior systems, the identifier is coupled in the recovery path and, in the event that the identified refrigerant is of the wrong type or is contaminated, the plumbing of the refrigerant handling system has already been contaminated. In this event, such prior systems would have to be shut down, disconnected from the vehicle and then connected to a separate scavenging unit to clear the system by removing the contamination.
Also, certain automotive manufacturer service specifications specify the precise amount of refrigerant to be recharged to the air conditioner after it is serviced, which amount must be accurate within a tolerance level, such as one ounce. The amount recharged is determined by comparing the weights of the refrigerant tank before and after recharge. But this only determines the amount which has left the recovery tank, and that amount will differ from the amount which enters the air conditioner by the amount left in the intervening conduits and hoses. Thus, the refrigerant handling system recharge protocol must compensate for this difference, and must also compensate for ambient conditions, such as temperature and pressure, which can affect the volume of the refrigerant. This compensation requires the use of very complicated algorithms in the system processor during the calibration procedure. This effectively precludes varying the length of the service hoses between the refrigerant handling system and the air conditioner, since every time the hose length is changed the system would have to be recalibrated and/or the software algorithm would have to be changed.
SUMMARY OF THE INVENTION
It is a general object of the invention to provide an improved refrigerant handling system, which avoids the disadvantages of prior systems while affording additional structural and operating advantages.
An important feature of the invention is the provision of a refrigerant handling system which permits refrigerant identification and purification determination without risk of contamination of the recycle and recharge plumbing of the system.
In connection with the foregoing feature, another feature of the invention is the provision of a system of the type set forth, which includes a refrigerant identifier isolated from the remainder of the system.
In connection with the foregoing feature, a still further feature of the invention is the provision of a system of the type set forth, which provides a sampling path in parallel with the recycling and recharge paths of the system.
Another important feature of the invention is the provision of a system of the type set forth, which permits more accurate control of the amount of refrigerant recharged to a refrigeration unit.
Yet another feature of the invention is the provision of a system of the type set forth, which permits change of the length of hoses coupling the system to an associated refrigeration unit, without requiring recalibration of the system.
In connection with the foregoing features, a further feature of the invention is the provision of a coupling assembly for coupling a system of the type set forth with an associated refrigeration unit, which provides a sample path in parallel with a service path through remotely controlled valves disposed closely adjacent to the associated refrigeration unit.
Certain ones of these and other features of said invention may be attained by providing in a refrigerant handling system including recycling/recharging apparatus for withdrawing refrigerant from a refrigeration unit, removing contaminants from the refrigerant, and recharging the refrigerant to the refrigeration unit, the improvement comprising: a coupling conduit having a first end with a first coupler for coupling to the recycling/recharging apparatus and a second end with a second coupler for coupling to an associated refrigeration unit, a remotely controllable first valve assembly connected in the coupling conduit closely adjacent to the second end for selectively controlling refrigeration flow through the conduit, a sample unit coupled to the second coupler and including a second remotely controllable valve assembly coupled to the recycling/recharging apparatus for selectively permitting or preventing refrigerant flow between said sample unit and the recycling/recharging apparatus, and a controller connected to the first and second valve assemblies for controlling operation thereof.
Further features of the invention may be attained by providing a coupling assembly for coupling an automotive air conditioner to a refrigerant handling system comprising: a housing, a first conduit passing through the housing and having a first end with a first fluid coupler for coupling to the handling system and a second end with a second fluid coupler for coupling to the air conditioner, an electrically controlled valve assembly coupled in the first conduit and disposed in the housing, electrical conductors electrically connected to the valve assembly for control thereof and having distal ends outside of the housing connected to an electrical connector, a second conduit communicating with the first conduit within the housing between the second fluid coupler and the valve assembly and having a distal end external of the housing, and a third fluid coupler at the distal end of the second conduit.
The invention consists of certain novel features and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention.
REFERENCES:
patent: Re. 32451 (1987-07-01), Proctor et al.
patent: 2464563 (1949-03-01), Doeg
patent: 2883834 (1959-04-01), McAshan, Jr.
patent: 4285206 (1981-08-01), Koser
patent: 4638973 (1987-01-01), Torrence
patent: 4909042 (1990-03-01), Proctor et al.
patent: 4938031 (1990-07-01), Manz et al.
patent: 5036675 (1991-08-01), Anderson, Jr.
patent: 5080132 (1992-01-01), Manz et al.
patent: 5086630 (1992-02-01), Van Steenburgh, Jr.
patent: 5095713 (1992-03-01), Laukhuf et al.
patent: 5097667 (1992-03-01), Gramkow
patent: 5168721 (1992-12-01), Hancock et al.
patent: 5335512 (1994-08-01), Hancock et al.
patent: 5339862 (1994-08-01), Haunhorst
patent: 5493869 (1996-02-01), Shirley et al.
patent: 5582019 (1996-12-01), Hanna et al.
patent: 5603223 (1997-02-01), Murray et al.
patent: 5617731 (1997-04-01),
Huvaere Donald G.
Pfefferle Dean P.
Doerrler William
Jones Melvin
Shaw Seyfarth
Snap-on Tools Company
LandOfFree
Isolated refrigerant identifier does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Isolated refrigerant identifier, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Isolated refrigerant identifier will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2598639