US 2659804 A
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Nov. 17, 1953 J. F. DUNN WATER HEATER Filed May 23,' 1952 Patented Nov. 17, 1953 UNITED sTATEs PATENT OFFICE 2 claims.
This invention relates to water heaters and particularly to electric water heaters of the immersion type in which an electrically heated element is adapted to be positioned in such a manner that it extends into a body of water to be warmed. It is particularly adapted to be used in connection with thermostatic means which control the flow of electric current to the heating element dependent upon temperature of the water within the vessel or chamber containing the same.
This invention is particularly adapted to be used in connection with the heating and maintaining at a proper heat of water within an open vessel, chamber, or sink. For example, it is well known to those whose duty it is to wash china and glassware in restaurants, bars, and other establishments, that in an open sink or vessel the washing water rapidly loses its temperature and will ultimately become suiiiciently cold to be of little assistance in connection with the washing operation. At present, hot water is customarily poured into such a sink and there is no method of keeping the same warm. When the water becomes cold it is necessary that the tank or vessel be drained and new water introduced. This results in a substantial loss of detergent or soap and disinfectant. Naturally it is not my desire to provide this device solely for the purpose of making it possible to use the same dishwater many times as that activity would promote unsanitary conditions. However, it is my intent to produce a device which maintains the water suiiiciently warm or at a predetermined temperature to permit its use until other factors, that is factors other than the temperature of the Water, render it advisable to drain the tank.
Other objects and advantages of the present invention will appear from the following specication taken in conjunction with the accompanying drawings in which:
Figure 1 is a side elevational view in cross section showing my device mounted in a suitable sink;
Figure 2 is a cross sectional detail taken along the line 2--2 of Figure 1;
Figure 3 is a cross sectional View o f a modication of the device illustrated in Figures 1 and 2; and
Figure 4 is a cross sectional detail taken along the line 4-5 of Figure 3.
As illustrated in the drawings, my device is adapted to be positioned in a tank IIJ into which water is introduced through a conventional faucet II, and from which it is drained through a conventional drain I2. Without my device it is 2 apparent that the surface of the water and the side walls and bottom of the tank I0 will provide such a large radiating area that the heat of the water will rapidly be lost.
My device consists generally of an electrical heating element I3 and may be of the type known as calrod unit. A calrod unit I3 terminates in a mounting block I4. The mounting block I4 valso supports a thermostatic element I5 or thermostatic switch of the type illustrated in Kercher Patent No. 2,314,989 granted March 30, 1943.
The switch elements and contacts are maintained in a water-proof shroud or cover I6. The heating element and the thermally responsive portion I1 of the thermostat I5 are retained in a casing I8 which is provided with a plurality of orices I9, as shown. The device is adapted to be supported from the bottom of tank I0 by means of a rubber suction cup 20. Suitable electrical conduit 2| is provided so that the device may be connected to a suitable source of electric current, preferably 220 volts A. C.
Operation of the device may briefly be der scribed as follows: The device is connected to a suitable source of electric current as previously explained and is positioned within the tank I0, in such a manner that the suction cup 20 engages the bottom of the tank and maintains the device in the predetermined position with respect to the tank. The thermostatic switch I5 is set at a predetermined temperature and, assuming the Water Within the tank I0 to be below that temperature, a circuit will be closed through the thermostatic switch I5 to the heating element I3. The water is heated to the desired temperature and because of the action of the thermally responsive element I'I the thermostatic switch is opened, thereby opening the circuit and preventing the water from being heated to a higher temperature.
In this manner it is apparent that the water within the tank or vessel IIJ will be maintained at a substantially constant temperature regardless of the radiation from the surface of the water and from the walls and bottom of the container I8. It will be unnecessary therefore, to drain the tank simply because o1' the lowered temperature of the water. The factors controlling the changing of the water will be sanitary factors alone.
A modication of the device is illustrated generally in Figure 3. The casing I8a is circular in cross section, as viewed in Figure 4, and the bottom wall of the casing I8a is provided with an orince and a threaded stud 22. The threaded stud 22 is adapted to cooperate with a thread in elongated threaded member 23 to the long end of which there is attached a suction cup 20. By turning the member 23, the distance between the suction cup 20 and the bottom of the casing lila may be adjusted. In this way it is possible to adapt my device to different depth tanks so that the mounting block I4 is always well above the surface of the water.
The tubular ycasing I8a is also provided with an appropriate number of orices lila to permit the water to flow in and out of the casing through the orifices. baie 24 in the form of a helical flight secured to the inner walls of the tubular casing is provided. The effect of these baffles will be to take advantage of the convection currents of the water `through my device and to provide better circulation of the water through the entire apparatus.
It is apparent from the foregoing that I have provided adevice which is readily adaptable to yarious depth tanks and which will maintain the Water withinV the tanks at a predetermined temperature. The casing i8 will prevent the user from coming into direct Contact with the heating element. The device is portable and may be used in various locations. The thermally re sponsive element is easily regulated to provide the varying degrees of temperature, as may be required.
1. In an immersion type heating element adapted to heat the water in a sink, an electric resistance element connected to a suitable source of electric energy, a thermally-responsive member in series therewith and adapted to control the flow of electric energy to said resistance ele- `ment, a casing surrounding said resistance elei ment'and said thermally responsive element, pas- -sageways in said casing permitting the inflow and outflow of water with respect to said casing,
In addition it will be noted that a and means for positioning said casing within said sink, said means comprising a suction cup adapted to engage the bottom of said sink and adjustable means connecting said suction cup to said casing comprising a threaded element adapted to engage the threaded member in said casing.
2. In an immersion type heating element adapted to heat the water in a sink, an electric resistance element connected to a suitable source of electric energy, a thermally responsive member in series therewith and adapted to control the flow of electric energy to said resistance element, a casing surrounding said resistance element and said thermally responsive element, passageways in said casing permitting the inflow and outflow of water with respect to said casing, a baffle in said casing in the form of a helical night to impart a whirling motion to the upwardly rising water within said casing, and means for positioning said ,casing within said sink, said `means ,comprising a suction cup adapted to engage the bottom of said sink and adjustable means connecting said suction cup to said casing comprising a threaded f' element adapted to engage the threaded member in said casing.
References Cited in the le of` this patent UNITED STATES PATENTS Number Name Date 1,069,372 Bellv Aug. 5, 1913 1,671,677 Keeton May 29, 1928 1,837,000 Wertz Dec. 15, 1931 2,429,303 Apatow Oct. 21, 1947 FOREIGN PATENTS Number Country Date 372,675 Germany Mar. 31, 1923