US2032884A - Safety alarm for gas burners - Google Patents

Description

Mh 37 19355 w. Moi-mm1 SAFETY ALARM FOR GAS BUHNERS Filed April 24, 1950 P ing, l

Patented Mar. 3, 1936 UNITED STATES PATENT OFFICE SAFETY ALARM FOR GAS BURNERS William Mohlman, Eggertsville, N. Y. Application April 24, 1930, Serial No. 446,842

1 Claim.

This invention relates to safety alarms for gas burners.

One of the objects of this invention is the pro-- vision of improved means associated with a gas burner or burners to cause a signal, either audible or visible, to be given in the event the gas pressure fails and extinguishes all burners.

Another object of my invention is to provide, in association with a pilot light and the main burner or burners of a stove, heater, and the like, means to automatically light the main burner or burners in the event that the latter are acci. dentally blown out and to prevent the escape of gas from the main burner or burners in the event that a child turns off the gas and playfully turns the gas on again, or in the event the gas is accidentally turned on after having been turned o.

A still further object is to provide a normally open thermostatically-controlled circuit closer in association with the pilot light; said circuit closer being of novel construction and serving to establish an electric circuit in the event of the pilot light becoming extinguished.

With the above and other objects in view to Q5 appear hereinafter, my invention consists in the novel features of construction, and in the arrangement and combination of parts to be hereinafter described, and more particularly pointed out in the subjoined claims.

In the drawings:

Fig. l is a plan View of a four-burner stove; part of the top being broken away to illustrate the main burners, the location and association of the pilot-burner thereto, and other parts of my invention in one of the forms now considered desirable.

Fig. 2 is an enlarged vertic-al section through the pilot-burner and associated parts, taken on line 2-2, Fig. 1.

4o Fig. 3 is a horizontal section taken on line 3--3,

Fig. 2.

Fig. 4 is an enlarged vertical section taken on line 4-4, Fig. 1, looking toward the left.

V Fig. 5 is a plan view of the control valve, part 4.5 of the regulating valve and a portion of the gas supply pipe leading to the pilot-burner.

Fig. 6 is a horizontal section taken on line 6-6, Fig. 4. 1

Fig. '7 is an enlarged section taken on line 1-1,

50 Fig. 1.

Y Fig. 8 is a modification of my invention.

In the particular application of my invention shown in the drawings, the numeral I0 designates a kitchen stove having the usual top, shown 5 5 partly broken away, but invariably provided with openings .directly over the burners adapted to be closed with lids or griddles. The main burners, designated Il are therefore exposed, as well as various parts adjacent thereto to better illustrate this invention. Each of said burners has 5 an individual gas-pipe I2 connected therewith, so that they may be lighted 4at will. The usual air-mixer I3 is connected to each pipe and gascocks I4 connected to the gas supply pipe I5 project into vthe air-mixers in the usual way. 10

, Arranged equi-distantly between the main burners IIis a pilot burner I6 which is enclosed in a casing I1. This casing has a top wall I8, a surrounding or peripheral wall I9 and a bottom 20 through which a gas pipe 2l extends from 15 the gas supply pipe I5, the pilot-burner I6 being threaded onto the inwardly-extending portion of pipe 2 I, which is immovably secured in said bottom by nuts 22, 23 applied thereto at opposite sides of the bottom. The pilot-burner may be 20 of any construction and is designed to consume the gasissuing therefrom in the form of a steady comparatively small ame. The bottom of the casing I1 is provided with air openings 24 and the surrounding or periph- 25 eral wall I9 also has air openings 25. The necessary air to maintain the pilot flame may, however, be lfurnished in any other approved manner. AThe main burners I I have safety lighter-pipes orconduits 26 formed integrally therewith, or 30 connected thereto as shown in Fig. 8. Said safety lighter pipes are perforated at intervals along their length, as at 21, and extend into the air openings 25 in pilot-burner casing I1, their outer ends ,terminating in close proximity to the pilot- 35 burner. The purpose of these safety lighterpipes is to conduct gas from the main burners to the name of the pilot-burner, and they may therefore be disconnected from the main burners and arranged in any manner which will insure the passage of the gas from the main burners to the pilot-,burner and the conveying of a flame from thepilot-burner back to the gas escaping directly from the burners. While I consider any meanssuitable to accomplish such action as falling fully within the scope of the appended claims, Iv have found the gas and flame-conveyingl means shown and described very effectual. s Pipe 2I supplying gas to the pilot-burner has a regulating valve 28 therein provided with a 50 tapering port 29, opened to any desired degree by a needle valve 30 threaded through the casing of the valve and having its pointed end entering saidport to provide for the passage of the ydesired quantity of gas therethrough, de-

pending on the size of the pilot ame required, and at times on the gas pressure.

In pipe 2| there is also arranged a shut-olf control valve 3|. This valve is shown between the regulating valve 28 and the gas supply pipe 5, but may be located between the regulating valve and the pilot burner, if desired.

Carried by and insulated from the surrounding or peripheral wall I9, or as it may be termed, the side wall of the pilot burner casing, is a binding post 32 which carries a xed electrical contact 33. A second binding post 34 is carried by and insulated from said side wall I9 and has electrical connection with a movable contact 35. In the form shown, said Amovable contact is carried by a vertically-disposed arm 36 pivotally and electrically secured at a point between its ends to the inner end of the 'binding post 34 and having its lower end enlarged to serve as a weight tending to swing the upper end thereof, and more particularly the contact 35 at the upper end thereof, in contact with the fixed contact 33, except when prevented by the heat of the pilot flame, which is utilized for such purpose. The parts just described form a circuit closer. Separation of the contacts 33 and 35 is accomplished by means of a thermostatic device which, in the form shown is a slender rod or member 3`| located over the pilotburner and horizontally disposed so that the pilot flame plays thereagainst, or at least so that the heat from the pilot flame Will be effective thereon.

'I'his thermostatic rod or member, of course, possesses the qualities of expanding under heat and contracting when cooled, and it is adjustably arranged in the side wall I9 of the pilotburner casing and insulated therefrom. For this purpose the outer portion of said rod or member is enlarged and screw threaded, as at 38, intoan insulating bushing 39 secured in said side Wall in any suitable manner, and it has a knurled head 40 at its outer end for conveniently adjusting the rod to bring the inner end thereof in proper relation to the movable or pivotal contact arm 36, so as to allow the contact 35 of said arm to engage the fixed contact 33 when the thermostatic rod or member is contracted or cooled, and to cause said movable contact to move away from the fixed contact when the thermostatic rod is expanded by the pilot flame or the heat therefrom. Y

This thermostatic rod is normally in engagement with or may be spaced from the pivoted contact arm 3B beneath the pivot thereof, and in either case, the rod is contracted sufficiently to allow the'pivoted arm 36 to assume a position which will bring the contact 35 thereof in engagement with the fixed contact. When, therefore the pilot-burner is lighted, the heat therefrom will cause the thermostatic rod to expand and swing the lower weighted end of the contact outwardly, while the upper or contact end swings inwardly away from the fixed contact 33; thus breaking an electrical circuit which includes a bell 4| or some other suitable signal or alarm, a battery 42 or other source of current, and suitable current conductors of any kind leadingV to the binding posts 32 and 34. In the drawings, I have shown wires 43, v44, 45 and 45 and the gas pipes l5 and 2| utilized for such purpose.

The shut-off valve 3| in the gas pipe 2| leading to the pilot-burner, comprises a casing 4l and a rotatable valve plug 48 therein through which a passage 49 is formed capable of passing all the gas required at the pilot-burner, even though said plug is not rotated to its full extent, and said Valve plug has a stem 53 projecting from its upper end and a laterally extending electrical contact from its periphery which is adapted, under certain conditions, to contact with a segmental electric contact 52 adjacent the valve casing and secured to an insulation support 53 surrounding the inlet branch 55 of the valve casing. Said segmental contact has one of the circuit Wires 46 connecting it With the binding post 34, and is therefore included in the electrical circuit in which the signal orV alarm is arranged. The contacts 5| and 52 serve as a circuit breaker.

I have illustrated and described the valve plug of `the shut-off valve 3| as provided with a stem, or it may have any other means whereby a separate or detachable handle or key will be employed for rotating the valve plug; thus guarding against children shutting off the supply of gas to the pilot burner and guarding against accidental closing of the shut-off valve.

Normally, the electrical circuit is broken by separation of the contacts 5| and 52 associated with the shut-olf valve 3|; and, therefore, when first lighting the pilot light, the valve plug in said shut-olf Valve is only partially rotated so that the contact 5| projecting from said valve plug will not come into engagement with the segmental contact 52. The necessary supply of gas will, however, pass through the passage 49 in said valve plug and be delivered to the pilot burner to be ignited. Consequently, no signal or alarm Will be given during such actuation of the shut-oli^ valve. However, when the flame or heat from the flame of the pilot burner has expanded the thermostatic rod 37, it will have swung the pivoted arm 36 to cause separation of the contacts 33 and 35, after which the valve plug may be fully opened so as to engage the contact 5| with the contact 52, or in other words, close the circuit breaker. No alarm, however, will be given, due to the fact that the electrical circuit is now broken at the thermostatically controlled circuit closer, and this condition is maintained so long as the gas escaping from the pilot burner is ignited. The size of the iiame at the burner is conveniently regulated by adjusting the needle valve 30 of the regulating valve 28.

If any one or more of the main burners are to be ignited, it is only necessary to open the gas cocks 4 in the supply pipes thereof, Vwhereupon the gas will issue from said burners and also travel through the lighter pipes or conduits 26, with the result that this gas becomes ignited at the pilot light, and as the gas issues from the perforations in said lighter pipes or conduits, the ame is carried to the main burners to ignite the gas escaping therefrom. It will therefore be understood that, so long as the pilot burner is lighted, the opening of the gas cocks controlling the main burners, whether accidental or intentional, will prevent the escape of gas from said burners, as the safety lighter pipes orconduits 26 Will instantly serve to light the escaping gas at said burners. V j

In the event that the pressure of the gas is reduced to a degree that the pilot light becomes extinguished, or if for any other reason gas is not supplied to the pilot burner, the thermostatic rod will cool and allow the pivoted arm 38 to swing on its pivot and establish an electric circuit, with the result that the signal or alarm is given.

The control valve 41 is then shut oi until a proper flow of gas is again assured.

It will be apparent from the foregoing, that my invention guards against asphyxiation, and also explosions in the event of the escaping gas being accidentally ignited.

Having thus described my invention, what I claim is:

In a device of the kind described, the combination with a casing, of a horizontally-disposed thermostatic rod adjustably secured within the peripheral wall of said casing and extending thereinto, two circuit-connected binding posts secured to said peripheral wall in vertical alinement opposite the point of securing said thermostatic rod to said wall, and a vertically-disposed contact element within said casing arranged for movement on a horizontal pivot Whose axis is disposed at a right angle to the axis of said thermostatic rod, said contact element being in electrical connection with one of said binding posts and mounted on said pivot between its ends and having its lower end weighted and its upper end adapted for contact With the other of said binding posts, said Weighted end causing said element to swing on said pivot in one direction into contact with said last-mentioned binding post when said thermostatic rod is contracted and said contact element being in engagement at a point beneath its pivot with said thermostatic rod and being caused to swing in an opposite direction away from said last-mentioned binding post when said thermostatic rod is expanded.

WILLIAM MOHLMAN.

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