US2520298A - Safety control means with flash - Google Patents

Description

Aug. 29, 1950 w. D. ANTRIM SAFETY conmox. MEANS WITH FLASH TUBE FOR OVEN BURNERS Filed Aug. 1a, 1945 WILL/AM 0. fiwm/M Patented Aug. 29, 1950 SAFETY CONTROL MEANS WITH FLASH TUBE F08 OVEN BURNERS William D. Antrim, Cleveland, Ohio, assignor, by

meme assignments, to Amliated uaa Equipment, 1nc., Uleveiand, Ohio, a corporation of Delaware Application August 18, 1945, Serial No. 611,356

2 Claims. (Cl. 158-1174) This invention relates to means for automatically igniting the oven burner of a gas range from a constantly burning pilot such as the pilot heretofore employed for ignition of the top burners of the range. Briefly, the invention contemplates the employment of a safety pilot immediately serving the oven burner, and a flash tube and pilot therefor efiective for ignition of the safety pilot from the top burner pilot.

The obJects of this invention are to provide a. control circuit for such flash pilot. which circult may employ an improved flash tube and pilot. as will appear hereinafter.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a diagrammatic view illustrative of essential parts of a range embodying the invention;

Figs. 2 and 3 are enlarged details in elevation and typical section, respectively. of the flash tube and flash pilot burner or charging means appearing in Fig. 1; and

Fig. 4 is an enlarged typical section of an embodiment of the valve employed.

With reference now to the drawings, and flrst to Fig. 1 thereof, I is the main burner located within the range oven as indicated by the broken line 2, the burner being located and adapted for either baking or broiling, or both, as the case may be.

The main burner gas supply is had from the manifold 3 by way of the manual valve means l, line 5, which includes thermostatic valve means lb, safety valve 6 and line I.

The valve means 4 embodies a manual on and oi! control as by manipulation of the handle lid. The valve means lb embodies a thermostatic throttling control responsive to the oven temperature had in the usual manner by a thermally responsive element 8 located within the oven and a transmission line 8a leading therefrom to the valve means. v,}lhe arrangement is such, as will be appreciated by one familiar with the art, that the manual valve means having the handle la is ahead of the thermostatic valve means controlled by the thermal element 8 so that the operator may turn the handle la to full open position and the thermostatic throttling effect of the valve lb will nevertheless follow, responsive to oven temperature.

The valve means l also controls the pilot line I, the line 9 having its gas supply from the line I, but ahead of the thermostatic valve means lb so that the line 9 is independent of even temperature.

The pilot line 9 leads to a safety pilot burner III by way of. a mixing device Illa where it is desired to employ primary air, the-pilot Ill being located to provide ignition to the main burner I.

Safety valve means is provided for control of the main burner gas supply line, responsive to the safety pilot burner' H). Details of such safety valve means are not material to this invention, but as here shown it includes a valve body 0 having a main gas inlet 5a and outlet 1a, a valve head lie for control of the outlet 1a and shown in closed position relative thereto in Fig. 4, an element H in thermal responsive relation to the pilot flame l0 and suitable mechanism for control of the valve head 6:1 by the thermally responsive element Ii. In the drawing such mechanism is of snap-acting characteristic in cluding a link 20 carrying the valve 6a, a lever 2i, having connection with the thermally responsive element H, and a tension spring 22 eifective between the link 20 and lever 2|. The link 20 is seated in a bridge 23 within the valve body and the lever 2| is mounted in a sealing diaphragm 24.

The arrangement is such that the safety valve and associated parts will be in closed position as illustrated Fig. 4 to cut oil gas supply to the main burner in the absence of operation of the safety pilot in, but when the thermally responsive element II is heated by operation of the safety pilot ID as indicated in Fig. l, the safety valve will open, moving its head But to the left, Fig. 4, to permit gas flow to the main burner as indicated by the large arrows Fig. 4; such safety valve operation, both on and ofi, being automatically responsive to operation of the safety pilot Ill.

The range is provided with a constantly burning pilot l2 here shown as fed directly from the manifold 3, and which may be the usual provision for ignition of the range top burners, as through flash tubes thereto, but not here illustrated.

What has thus far been described is generally old and well known in the art; and this invention provides flash tube means for igniting the safety pilot burner Hi from the constant pilot burner 12, automatically upon opening. of the oven burner control valve means 4.

For such purpose an open ended flash tube I3 having a cooperative flash gas supply tube may be provided as here shown. As indicated in detail in Figs. 2 and 3, the flash tube 13 is of 3 porous open construction as of woven wire and isflexible for ease of installation; and the flash pilot burner or charging means it comprises a tube extending within the flash tube I3 and a substantial distance therealong and provided therewithin with a number of small outlet ports Ila at intervals or spaced locations therealong. It will be appreciated that the flash tube and pilot here described may be, if preferred, of more conventional construction comprising the more usual rigid flash tube and single charging port or flash burner therefor.

The flash pilot burner i4 is served by a line I I which may include the adjusting valve l8 and which is controlled automatically from the pilot i0, but subject to the pilot line 9 and consequently to the manual valve 4 also, as follows: A connection i1 is provided leading from the pilot line 9 to the body of the automatic valve 0, by way of the inlet Ila. therein, the body hav ing an outlet l5a from which the line l5 has connection. A diaphragm I8 is so arranged in the valve body that it controls flow between the openings Illa and Ila, yet maintains both these openings at all times without communication with either of the openings 5a and la in the main burner gas line. The diaphragm I8 is under the control of a head IS on the main valve proper 6a, the arrangement being such that when the valve 8 opens to the main burner line 1, it closes to the flash pilot line i5 and vice versa, direction of flash pilot gas flow being indicated by small arrows in Fig. 4.

The valve means described, and herein illustrated in Figs. 1 and 4, and which is responsive to the safety pilot i0 through the action of the thermally responsive element H, is thus of dual nature with respect to the main burner gas supply. It is a safety valve which automatically permits gas flow to the main burner, ony during safety pilot operation. As to the flash tube, however, by virtue of the diaphragm l8 and head I 9, it admits energizing gas to the flash tube before admitting gas to the main burner and automatically cuts off flash tube gas during operation of the main burner.

The operation will be as follows, commencing with the manual oven burner control valve means in "of? position and only the constant pilot II! in operation:

When the operator desires operation of the burner I, the manual valve to is simply turned to full on position, the desired thermostatic oven temperature setting having been made at the thermostatic valve 4b.

Opening of the manual valve means admits gas to the lines 5 and 9. The thermostatic element if being cold, the valve 6 prevents flow to the main burner supply line I, but gas is admitted from the line 9 by way of the connection i1 past the valve 6, through the line I! to the ports Ha of the flash pilot burner [4, thus releasing a small energizing volume of gas within the flash tube l3 with distribution therealong. This gas mingles with the air within the flash tube to form a combustible mixture which is ignited by the constant pilot l2 and in turn ignite the safety pilot i0 which latter has been receiving gas from the line 9 since opening of the manual valve so that it has been purged of air.

Ignition of the safety pilot ll heats the thermal element i l which in turn shifts the valve 6 to cut of! gas supply to the flash pilot burner and admit gas to the main burner I which is infmediately ignited from the safety pilot.

On safety pilot outage for anycause, cooling of the thermal element H returns the valve 0 to safety position, cutting of! gas to the main burner and re-admitting gas to the flash pilot for automatic re-ignition of the safety pilot from the constant pilot.

When the oven is brought up to predetermined temperature by the main burner, the thermostatic valve means lb begins to throttle down the, main burner responsive to the thermal element 8. This, however, has no effect upon the gas pressure in the line I so that the safety pilot [0 continues in operation without impairment of its effect upon the thermal element ll; nor, should recycling take place following outage of the safety pilot, will there be any throttling effect upon the flash pilot burner. These are important advantages particularly as to the flash, which is necessarily somewhatcritical in many commercialinstallations.

I claim:

1. In a gasrange having a top pilot burner, an oven with a main burner therein, a safety pilot arranged to serve said main burner, gas supply means for said oven burner including a safety valve means controlled by said safety pilot and manual valve means, and gas supply means for said safety pilot subject to said manual valve means: means providing ignition for said safety pilot from said top pilot burner, .and including flash pilot burner means, flash tube means arranged to receive a gas charge from said flash pilot burner means, and have ignition of said charge from said top pilot burner, and means providing gas supply for said flash pilot burner means from said safety pilot supply means, and including valve means responsive to said safety pilot, to cut off said flash pilot burner means upon safety pilot ignition, and to pass gas to said flash pilot burner means upon safety pilot outage.

2. In a gas range having a top pilot burner, an oven with a main burner therein, a safety pilot arranged to serve said main burner, gas supply means for said oven burner including a safety valve means controlled by said safety pilot and manual valve means, and gas supply means for said safety pilot subject to said manual valve means: means providing ignition for said safety pilot from said top pilot burner, and including flash pilot burnermeans, flash tube means arranged to receive a gas charge from said flash pilot burner means, and have ignition of said charge from said top pilot burner, and means providing gas supply for said flash pilot burner means, and including valve means responsive to said safety pilot, to cut of! said flash pilot burner means upon safety pilot ignition, and to pass gas to said flash pilot burner means upon safety pilot outage.

WILLIAM D. ANTRIM.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED s'rs'ms Ps'rEN'rs Dobler Dec. 22, 1942 Certificate of Correction Patent No. 2,520,298 August 29, 1950 7 WILLIAM D. ANTRIM It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 2, line 53, after the word tube insert 14; column 4,-lines 27 and 47, after oven insert main;

and that the said Letters Patent should be read as-corrected above, so that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 28th day of November, A. D. 1950.

THOMAS F. MURPHY,

- Assistant aom/missioner of Patents.

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