US1506402A - Automatic fuel control for water heaters - Google Patents

Description

Au 26, 1924. f 1,506,402

H. C. AINSWORTH ET AL AUTOMATIC FUEL CONTHOQ FOR WATER HEATERS 7 Filed may 5, 1924 gmz n iou ygwwm yw attomug Patented Aug. 26, 1924.

UNITED STATES PATENT OFFICE.

HINCKLEY C. AINSWVORTH AND PERCY H. MURRAY. 0.15 LOS ANGELES, CALIFORNIA.

AUTOMATIC FUEL CONTROL FOR WATER,

Application filed May 5,

To all who-m it may concern Be it known that we, HINGKLEY C. AINs- WORTH and PERCY H. MURRAY, citizens of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Automatic Fuel Control for Water Heaters. of which the following is a specification.

This invention relates to automatic fuel controls of the type employed in connection with water heaters for turning on the fuel, when water is drawn from the hot water service pipe, and for turning off said fuel, when the water supply is shut off.

One of the principal objects of this invention is to insure closing of the fuel control valve when water is'drawn from the heating system and then shut off. One of the principal difficulties at present encountered in the 7 use of the, so-called, automatic type of water heater is that, when the water is heated to its boiling point or higher, a pressure is produced that maintains the fuel control valve in open position after the water is shut off at the faucet, and this invention avoids this diificulty.

Other objects and advantages will appear in the subjoined detailed description.

The accompanying drawings illustrate the invention:

Fig. 1 is a sectional elevation of an automatic-fuel control embodying the invention.

Fig. 2 is a reduced plan view of Fig. 1.

Fig. 3 is an elevation of Fig. 2 from the left thereof.

Fig. a is an elevation of a water heating system of which the invention constitutes a portion.

Referring to the drawings the following described structure is indicated therein. A pressure or plunger chamber 11 is provided with a plunger 12 which slidably fits in said chamber. The plunger 12 is secured to the lower end of a stem 13 which is pivoted at 1 1 to a lever 15 fulcrumed at 16 on a standard 17. The standard 17 may be mounted on or connected with the chamber 11.

The lever 15 is pivoted at 18 to a valve stem 19 which has its lower end projecting into a valve chamber 20, and said inner pro jecting end of the stem 19 is provided with a valve 21 adapted to close a port 22 in the bottom of the valve chamber.

Other means than those described above may be employed for operably connect- 1924. Serial No. 711,091.

ing the valve to the plunger as the invention is not limited to such construction.

The stems 13, 19 pass through stuffing boxes 23, 24, respectively, so as to insure against leakage of fluid around said stems.

The fuel is supplied to the port 22 through a suitable passage 25 which is connected by a pipe 26 to a fuel supply not shown. The fuel discharges from the chamber 20 through a pipe 27 which supplies the burner a of the water heater with which the invention is associated.

Water is supplied to the chamber 11 on one side of the plunger 12 through a port 28 which is connected by a pipe 29 to the water main. The portion of the chamber 11 on the other side of the plunger 12 also communicates with the port 28 through a duct 30.

In this particular instance a spring 31 is shown in the chamber 11 in position to tend to raise the plunger 12, and in the valve chamber 20 is a spring 82 tending'to close the valve 21. Thus both springs tend to close the valve 21 and, if desired, but one of them may be employed.

The construction so far described is not unlike that heretofore employed for fuel controls of this description but, heretofore, the port that is connected with the water coil 6 of the heater has been positioned in such manner that, when the water in the coil is heated to its boiling point or above, sufficient pressure is produced upon the upper face of the plunger in excess of that against the lower face to hold said plunger in valveopening position even when the water is turned off at the faucets. l/Ve have dis covered that, by placing this port, indicated at 83, so as to open into the duct 30, such pressure will not hold the valve open but will tend to close said valve. The importance in changing the position of this port 33 will be readily appreciated by those skilled in this art as it so frequently happens in drawing water from the water heating system employing the old fuel controls that, when sufficient water has been drawn and the faucet is closed, the plunger fails to operate to close the fuel valve and, accordingly, the flame continues beneath the water coil and will burn out the coil, unless the fuel control valve is manually closed. Under such circumstances, to effect closing of the fuel Valve, recourse is generally had to the services of a plumber or other person familiar with these devices and before such person arrives the water coil may be ruined by the long continued intense heat.

Assuming that the pipe 26 connects with a fuel supply, the pipe 27 to the water heater burner a, the pipe 29 to the water main and that the port 33 is connected by a pipe 34 to the water coil Z) of the water heater, and assuming that the faucet c of the hot water system is closed and that the valve 21 closes the port 22, the invention operates as follows:

The pilot light, not shown, of the water heater will, of course, be burning in the customary manner and, if hot water is desired, the faucet 0 of the hot water system will be opened, thus drawing water from the water coil 6 which in turn draws water through the port 33, duct 30, and from that portion of the chamber 11 that is beneath the plunger 12. It will be noted that the cross sectional area of the port 28 is great compared'with that of the duct 30 and, accordingly, the pressure below the plunger 12 is quickly reduced while the pressure above the plunger remains. The differential pressure causes the plunger 12 to descend, thus opening the valve 21 which permits the fuel to flow to the burner where it is lit by the pilot light, not shown. When a sufficient supply of hot water has been drawn and the faucet 0 is closed, the water pressurewill build up in the chamber 11 beneath the plunger 12 and such pressure, aided by the force of the springs 31, 32, will raise the plunger 12 and close the valve 21. Thus far the operation is not dissimilar to the operation of valves of this type of prior construction, Assuming, now, that the flame of the burner is sufficiently hot or endures for a sufficient length of time to heat the water in the water coil to the boiling point of water at atmospheric pressure, or a higher temperature, it will be understood that when this occurs and the faucet c is then closed, the highly heated water in the water coil will instantly increase the pressure against the lower face of the plunger 12 above that on the upper face of said plunger so as to reinforce the action of the springs and effect instant closing of the fuel valve. To obtain the desired instantaneous closing of the fuel valve 21, when the faucet is closed, it is important to insure that the reflex pressure of the heated water be imposed against the under face of the pliilnger quicker than against the upper face of said plunger and for this reason means is provided to restrict the duct 30 between the water intake and discharge ports 28, 33. This duct-restricting means, in this instance, is in thev form of a needle valve 35 adjustably mounted in the port 28 to control the passageof water between the port 28 a ported passage for fuel, a valve for said port, a plunger chamber, a plunger. slidably fitting the chamber, there being a water inlet portin the plunger chamber on one side of the plunger and a duct connected with, saidport and communicating with the chamher on the opposite side of the plunger and there being a water outlet port communicating with the duct leading to a heating element, means restricting the duct between the water inlet port and the water outlet'port, and means operably connecting the valve with the plunger. I v

2. The combination with a water coil and a burner to heat said coil, of a ported fuel passage connected with the burner, a valve for said port, a plunger chamber having a water inlet port, a plunger slidably fitting the chamber, means operated by the plunger when the fluid pressure is reduced on one side thereof to open the valve, and a duct connecting the chamber to the coil and having restricted communication with said water inlet port and relatively free communication with the coil and lower side of the plunger, and operating when water is drawn from the coil to reduce the fluid pressure on said side of the plunger and operating when the water in the coil is heated to its boiling point to instantly increase the fluid pressure on said side of the plunger above that on the other side of the plunger to effect movementof the plunger into valve-closing position.

3. An automatic fuel control comprising a ported passage for fuel, a valve for said port, a plunger chamber, a plunger slidably fitting the chamber, there being a water inlet portin the plunger chamber on one side of the plunger and a duct connected with said port and communicating with the chamber on the opposite side of the plunger, means to restrict the duct between the water inlet port and the plunger chamber, means to carry the water that flows into the duct from the water inlet port to a water heating coil, said means functioning upon reflex pressure due to expansive force of the heated water to create a greater pressure against said opposite side of the plunger than said first side to effect instant closing of the fuel valve when the flow of water from the coil ceases.

4. The combination with a water coil-and a burner to heat said coil, of a ported fuel passage connected with the burner, a valve for said port, a plunger chamber having a atively high temperature and flow of Water Water inlet port, a plunger slidably fitting from the coil ceases to permit the last named the chamber, means operated by movement means to efiect greater pressure upon that of the plunger in opposite directions to open side of the plunger remote from the inlet 5 and close the fuel valve, means connecting port than upon the Water in the inlet port 1 the Water coil to the inlet port and to the until the fuel valve is closed. plunger chamber on that side of the plunger Signed at Los Angeles, California, this opposite to the side exposed to pressure 25th day of April,1924. through the inlet port, and means operating HINCKLEY C. AINSVVORTH.

10 when the Water in the coil is heated to a rel- PERCY H. MURRAY.

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