Thermal measuring and testing – Temperature measurement – With fluid flow deflector
Reexamination Certificate
2000-08-25
2001-05-22
Bennett, G. Bradley (Department: 2859)
Thermal measuring and testing
Temperature measurement
With fluid flow deflector
C374S040000
Reexamination Certificate
active
06234670
ABSTRACT:
BACKGROUND OF THE INVENTION
This application relates to the art of temperature sensing and, more particularly, to temperature sensing of a flowing liquid. The invention is particularly applicable for use in sensing the temperature of water flowing to a clothes washing machine and will be described with specific reference thereto. However, it will be appreciated that the invention has broader aspects and can be used for sensing the temperature of other flowing liquids in other environments.
The temperature of the hot and cold water supplied to a washing machine varies greatly. For example, in many geographical areas, the cold water supply often has a much lower temperature during winter than during summer. The temperature of the hot water supply varies greatly from one household to another depending on the setting of the hot water heater and the distance that the washing machine is located from the water heater. Also, there is often a difference in the flow rates of the hot and cold water. For these reasons, simply opening both the hot and cold water valves one hundred percent to supply warm water results in an actual warm water temperature that has extremely wide variations. Water that is too hot may damage certain clothes and water that is too cold may not clean effectively. In addition, the unnecessary use of excessive hot water is energy inefficient and environmentally unfriendly. Therefore, it would be desirable to have an arrangement for accurately sensing the temperature of warm water being supplied to a washing machine in order to cycle or modulate at least the hot water valve and thereby maintain a relatively constant warm water temperature.
SUMMARY OF THE INVENTION
In accordance with the present application, a stream divider is molded across the liquid flow passage of a molded plastic fitting. A thermistor is encapsulated in the stream divider for sensing the temperature of liquid flowing therepast. The change in resistance of the thermistor with temperature is sensed by an electronic control that then cycles or modulates at least the hot water value to maintain a relatively constant temperature of the liquid flowing through the fitting.
In a preferred arrangement, the stream divider is centrally located between opposite ends of the flow passage in the fitting. The stream divider also extends diametrically across the cylindrical flow passage and divides the passage into two equal areas that have a combined cross-sectional area that is between 35-65% of the cross-sectional area of the flow passage.
The stream divider preferably has somewhat of an airfoil shape to minimize turbulent flow and effectively split the flowing stream to flow around and past the stream divider in intimate contact therewith.
It is a principal object of the present invention to provide an improved fitting for sensing the temperature of liquid flowing through the fitting.
It is another object of the invention to provide an improved fitting having a stream divider extending across an internal cylindrical flow passage and with a thermistor encapsulated in the stream divider.
It is another object of the invention to provide a one-piece molded plastic fitting having a thermistor molded within a flow passage in the fitting.
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Bennett G. Bradley
Harness & Dickey & Pierce P.L.C.
Therm-O-Disc Incorporated
Verbitsky Gail
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