Automatic temperature and humidity regulation – Thermostatic – With pressure control
Reexamination Certificate
2000-07-26
2001-12-04
Tapolcai, William E. (Department: 3744)
Automatic temperature and humidity regulation
Thermostatic
With pressure control
C062S225000, C062S296000
Reexamination Certificate
active
06325296
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
MICROFICHE APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
The present invention relates to expansion valves of the type employed for controlling flow of liquid refrigerant at relatively high pressure to enable the refrigerant to be circulated at a substantially reduced pressure through a heat exchanger or evaporator over which is directed a flow of air for cooling a compartment such as the passenger compartment of a motor vehicle. Such expansion valves are well known in the art and one type of known expansion valve is controlled by a thermally responsive liquid filled capsule which utilizes the expansion and contraction of the liquid fill in the capsule to move a diaphragm which movement in turn operates a valve member for controlling flow through the valve from a minimum bleed flow to a maximum flow. Furthermore, it is also known to provide a supplemental solenoid operated shut-off valve in the inlet of the expansion valve for permitting complete shut-off of the flow remotely by an electrical control.
However, problems have been encountered in the aforesaid type of valve inasmuch as flow noise has been generated within the valve which has been found to be prohibitive from the standpoint of annoyance to the occupants of the passenger compartment of the motor vehicle. Efforts to muffle the sound in the refrigerant conduits and in the mounting of the valve body to the vehicle structure have generally proven unsuccessful. Therefore, it has long been desired to provide a simple and low cost, but effective way of reducing or minimizing the flow noise of refrigerant flowing from the high pressure inlet side to a substantially reduced lower pressure outlet in a refrigerant flow control or expansion valve.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a solution to the above-described problem of quieting flow noise in a thermal expansion valve for controlling flow of refrigerant from the high pressure effluent of a condenser to a substantially reduced pressure evaporator and particularly in thermal expansion valves of the type having a supplemental solenoid operated shut-off valve in the inlet. The valve assembly of the present invention includes a reduced flow area passage between the high pressure inlet and the electrically operated shut-off valve by providing a micro-porous element in the reduced area flow passage for providing flow through a plurality of small passages in the micro-porous element. The present invention thus permits a simple modification of the valve body to include the micro-porous element in a passage formed in the inlet and therefore eliminates the need for complete retooling of the valve body. The micro-porous element is preferably a sintered bronze or sintered stainless steel element which is sufficiently robust and low in manufacturing cost to provide a simple yet cost-effective technique for modifying an existing thermal expansion valve to reduce flow noise. In the preferred practice of the invention, the micro-porous element has a porosity in the range of about forty to one hundred eight microns.
REFERENCES:
patent: 2573522 (1951-10-01), Watt
patent: 3815379 (1974-06-01), Scherer et al.
patent: 4381651 (1983-05-01), Kubo et al.
patent: 6148631 (2000-11-01), Watanabe et al.
patent: 5-141813-A (1993-06-01), None
patent: 5-264129-A (1993-10-01), None
Eaton Corporation
Johnston Roger A.
Tapolcai William E.
LandOfFree
Quieting a thermal expansion valve does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Quieting a thermal expansion valve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quieting a thermal expansion valve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2564870