US2374459A - Burner control - Google Patents

Description

April 2 1945- E. w ROBERTS ET AL I 2,374,459

- v BURNEfi CONTROL Filed Dec. 28, 1940 o o a a o 0 0 o 0 o a 0 0 0 0 u 9 c- 0 5000000 000060 o 27 w a 0 OOoOoaooo 55 INVENTORB 542'; M4 P055273 JZ/A /z 5 Com 255 A ORN Y5 Patented Apr. 24, 1945 I BURNER CONTROL Earl W. Roberts, Hickory Island, Mich., and. Julius Converse, East Cleveland, Ohio, assignors to The Bryant Heater Company, Cleveland, Ohio, a corporation of Ohio Application December 28, 1940, Serial No. 372,118

2 Claims.

This invention relates to improvements in burner controls, and has reference particularly to automatic safety valve controls, the primary purpose of which is to prevent. the delivery of gas to a burner except when a pilot flame is available to ignite the burner gas.

A supply control valve, either manual or thermostatic, is retained in addition to the automatic valve in substantially all installations of this kind. After a period of operation the burner may be turned off by closing this supply control valve. Customarily the opening of the supply control valve is made effective also to admit gas to the pilot, and in the event that the pilot should go out during operation of I the burner, thereby causing the automatic valve to close, gas to the burner would be cut off but gas would still flow through the cold pilot. In some cases this might do no harm, as where the gas used is lighter than air and finds its way out through the flue. However, in the case of so-called bottled gas, that is liquified gas sold in metal containers for consumption in rural'communities, the gas is heavier than air and may collect in such volume as to cause a serious explosion when accidentally ignited. Furthermore this bottled gas has an unpleasant odor and is relatively expensive, so that it is desirable for these additional reasons as well as for safetys sake to terminate flow from the pilot as well as from the burner in the event that the pilot is blown out or otherwise extinguished accidentally. The present invention accomplishes that result. It does so by providing flow to the pilot during the ignition period only from the line ahead of the automatic valve, and after ignition from the line between the utomatic valve and the burner. Hence after the system is in operation the automatic valve controls the pilot gas as'well as the main burner gas.

An object of the invention therefore is to put the pilot gas under control of the automatic valve except at the time of lighting the burner.

Another object is to pr vide in conjunction with operator controlled means for taking pilot gas temporarily from thedine ahead of the, automatic valve, means also for causing the ignition of the pilot gas electrically.

Other objects and features of novelty .will appear as we proceed with the description of those embodiments of the invention which, for the pur poses of the present application, we have illustrated in the accompanying drawing, in which Fig. 1 is a diagrammatic view of conventionalized apparatus embodying the invention, and

Fig. 2 is a similar view of a modified form of the invention.

In the drawing It] represents a burner which is fed with fluid fuel, such as bottled gas, through a conductor I2 which is connected at its opposite end with an automatic valve 13 to which gas line I 4;, Fig. 1, or I4, Fig. 2, is connected.

The invention contemplates the use of a, pilot thermostat and a valve automatically actuated thereby. In the embodiment herein disclosed the automatic valve comprises a valve piece l5 normally held to its seat by a coil spring I6. A valve stem l7 upon which the valve piece is carried projects through a bore in the valve housing to a point where it may be engaged by an adjustable post [8 on the free end of a lever [B pivoted at 20 to a bracket 2| that is carried by the housing of valve l3. Lever i9 also has a small projection 22 to which power may be applied by a slide rod 23 that is movable through a pipe 24 carried at one end by bracket 2| and at the other end by a bracket 25 which may be attached to a suitable support, such for instance as the burner l0. The rod 23 at this end engages the free leg of a thermostat which may comprise a'horseshoe shaped thermal. element 26, the other leg of the horseshoe being mounted upon'bracket 25 and being therefore fixed in position. A pilot 21 mounted midway between the legs of the horseshoe is adapted to play a flame upon the curved portion of the horseshoe and to cause the same to expand, thereby exerting pressure through rod 23 upon lever l9 and raising valve piece l5 against the action of spring I6.

On the other hand when the pilot flame is out thermal member 26 cools and spring I6 is free to force valve piece 15 into contact with its seat and at the same time through valve stem ll and lever I9 to return rod 23 to its normal position. The automatic valve and a pilot responsive operating means therefor just described are well known in the art, but other means for accomplishing the same purpose may be used if desired.

Referring now more particularly to Fig. l of the drawing, we have shown at 28 a supply control valve located in the gas line M, which valve must be open in order to operate burner l0, and the closing of which terminates the burner operation and in this form of the invention the pilot operation as well. 30 is a small valve located at some point conveniently reached by the operator. It has two valve chambers 3| and 32. Chamber 3| is connected by a small tubular conductor 33 with the pipe [4 between valves 28 and I3. Chamber 32 is connected by a similar conductor 34 with conductor I2, and by a further tubular conductor 35 with pilot 2'I. A push button 36 carries a stem 3i having a valve head 38 on its free extremity which in the position illustrated closes chamber 3|, being held normally in that position by a coil spring 39. When the push button is depressed against the action of spring 39 however chambers 3I and 32 are brought into communication, thereby connecting conductors 33 and 35, while at the same time the end of the valve head 38 engages a valve seat 40 surrounding the passage with which conductor 34 communicates. It will be seen therefore that ordinarily conductors 34 and 35 arein communication, and that while the push button is depressed conductor 3 is cut off and conductors 33 and 35 are maintained in communication.

In the event that electric ignition for the pilot is provided, we control it also by the push button 35. One means for accomplishing this is illustrated schematically in Fig. 1, where an igniter coil is shown at M grounded on one side at 42 and connected by an electric conductor 43 with the secondary of a transformer M, the other terminal of the secondary being connected with one contact of switch Q5. The other contact of this switch is mounted upon a small lever 46 pivoted intermediate its ends to a fixed support II, which is grounded at :28, and the opposite end of the lever being arranged to be engaged by the head of the push button when depressed. A spring 39 normally separates the switch contacts.

In the form of the invention illustrated in Fig. 2 the control apparatus and the gas connections are approximately the same as the corresponding parts in Fig. I. But instead of a supply control valve 28 in the feed pipe It in advance of the conductor 33 we place it between that conductor and valve I3. We may also employ a valve 50 in conductor i2, an oven thermostat valve for example, capable of cutting oiT the flow of gas to the burner Iii but leaving the flow of gas to the pilot 2'! unafiected. Also in this form of the invention we have omitted the electric ignition apparatus. Consequently the pilot in this case would have to be lighted with a match after the push button 36 had been depressed. In this form of the invention we may also employ a pivoted latch normally held out of the way by a spring but which may be swung into engagement with the end of push button 35 when the latter has been depressed, for releasably holding it in that position.

Opcration.--In the I form of the invention when the operator desires to light the burner he first turns on the valve 23 which lets gas into the chamber 3i of valve 36. He then depresses push button 35 which brings chambers 3i and 32 into communication and feeds gas to the pilot, the depression of valve head 36 closing off conductor 34. At the same time switch 35 is closed and igniter coil ii is energized, and thereby the pilot gas is ignited. Small flames from the pilot then play upon thermal member causing it to expand and press against the end of rod 23, which pressure is transmitted by that rod to lever I9 and is caused to raise valve stem I'I thereby opening automatic valve I3, when gas flows from pipe It through valve I3 and conductor l2 to burner I0. Gas flowing'from the burner is ignited by the pilot 2?. As soon as the operator observes that the burner is lighted he may release push button 36. Coil ill is then deenergized and communication between conductors 33 and 35 is broken.

However, another path for pilot gas is then set up from conductor I2 through conductors 34 and 35, so that there is no interruption of flow to the pilot, and the latter continues to burn and to maintain automatic valve I3 open. It will be observed therefore that the push button valve serves to provide gas for the pilot from the line ahead of the automatic valve I3 until that valve is opened by the operation of the pilot, and the push button is released, after which the gas to the pilot is drawn from the line between the automatic valve and the burner. When the operator wishes to discontinue the operation of the burner he closes valve 28 which cuts off gas both to the burner and to the pilot, after which the thermal member 26 cools and permits spring I6 to close the automatic valve. Now, in the event that the pilot should go off for any reason during a period of burner operation, the automatic valve I3 would close, and since the automatic valve then controls gas flow to the pilot as well as to the main burner, both of these burners would be extinguished.

In that form of the invention illustrated in Fig. 1 the pilot goes out every time that the main burner is turned off and a complete lighting cycle must take place before the burner may go on again. In the invention according to Fig. 2 however the pilot may remain on when the main burner is off and thus be ready to light the burner whenever gas to the burner is turned on. When the valve I3 is closed the pilot as well as the main burner will be off. Thereafter to light the burner the operator must depress push button 36 which opens communication between conductors 33 and and permits gas to flow to the pilot. The pilot is ignited by a match and the pilot flame then functions through the thermal member 26, rod 23, lever I9 and valve stem I! to open automatic valve I3, whereupon gas flows from line I4 through valve I3, valve and conductor I2 to burner, and the latter is ignited by the pilot. Thereafter the closing of valve 50 merely extinguishes the main burner, leaving the pilot in operation, so that it serves as a constantly burning pilot, and the push button is not then called into use except when the pilot goes out. If the pilot does go out for any reason however, then the automatic valve closes and cuts off pilot gas, and the burner may not be lighted again without the manual operation of the push button.

When the push button 36 is not depressed, the closing of valve 28' will cut off gas to both the burner and the pilot. However, a continuous pilot may be provided during desired periods, as where an operator wishes to use the oven at intervals throughout a day, by latching the push button in depressed position. The operator may then turn oIT the burner by closing valve 28', but the pilot will remain on and the valve I3 will remain open, so that operation of the oven may be resumed at any time by merely turning on valve 28. At the end of the day however the operator may unlatch the push button and the system will then be shut off Hence in both forms of the invention the automatic valve controls the pilot as well as the main valve when once the burner is lighted, but may be by-passed temporarily by the manual depression of the push button during a lighting cycle.

Having thus described our invention, we claim:

1. In apparatus of the class described, a burner, a pilot therefor, a gas supply line for the burner, an automatic valve in said supply line responsive only to pilot operation, a manual valve,

conductors from the upstream and downstream sides respectively of the automatic valve to the line between the burner and the automatic valve and a second conductor for pilot gas connected with the supply line on the opposite side of the v automatic valve, manual control means for selecting one only of said conductors, said control means being biased towards selection of said first conductor, and latch means for releasably holding said control means in position for communication between said pilot and said second 10 conductor.

EARL W. ROBERTS. JULIUS CONVERSE.

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