US2236673A - Safety device for gas heaters - Google Patents

Description

H. L. COLE 2,236,673

SAFETY DEVICE FOR GAS HEATERS Filed Sept. 9, 1939 2 Sheets-Sheet J.

V5 71 HUGH L. COLE April'l, 1941.

2 Sheets-Sheet 2 H. L. COLE SAFETY DEVICE FOR GAS HEATERS Filed Sept. 9, 1939 I I I: g

, QM HUGH L. COLE I Patented Apr. 1, 1941 SAFETY DEVICE FOR GAS HEATERS Hugh L. Cole, Chicago, Ill., assignor to Ooles Hot Blast Mfg. 00., Chicago, 111., a corporation of Illinois Application September 9, 1939, Serial No. 294,101

1 Claim.

The present invention relates to a safety device for a gas fired space or room heater for preventing opening of the gas valve, after it has once been closed, if and when the pilot light flame has been, intentionally or unintentionally, extinguished, and is adapted for use with gas heaters in which the gas is turned on and off several times a day, to save fuel.

The safety device of the present invention is especially useful in connection with gas heaters sold to persons of moderate or little means, i. e., those who live in stove-heated rooms, as it may be manufactured at a low price, thus adding but little to the retail price of a heater.

It is the present practice of'some of the gas companies not to sell space heaters unless equipped with some sort of safety device operable to prevent opening of the gas supply to the heater burners in the event the .pilot light flame is extinguished. There are such devices now on the market, but these are expensive, adding from $5.00 to $10.00 per heater to its retail price. The consequence is that the poor man does not buy a gas heater, as the added cost for the safety device is too great, the gas company loses a customer, and the prospective customer is denied gas heat and must perforce utilize some other means for heating his modest home or room.

It is a well recognized fact that a gas heater requires little if any attention. When such heaters are used by poor people, oftentimes the gas supply is out ch several times a day to save gas.

'If perchance a pilot light flame should be extinguished, intentionally or otherwise, and the gas supply valve left opened, with no attendant ignition of the gas, the operator in applying a match to the combustion chamber would cause an explosion, sometimes with disastrous results.

The present invention is directed to a safety device which may be applied to a gas fired space heater for preventing the opening of the gas supply to the heater burner, after the valve has once been closed, in the event the pilot light flame is extinguished.

Another object of the invention is to provide such a safety device which is efficient for accomplishing the purpose intended and which may be manufactured at low cost so as to keep the selling cost thereof, when applied to a heater, to a Cir opening of the gas valve which controls the flow of gas to the burner of a heater.

A still further object of the present invention is to provide a safety device applicable to a gas fired space heater, which device complies with the safety requirements of gas companies relating to such device.

The invention has for another object the provision of a safety device for preventing the opening of a gas supply line to the burner of a space heater when the pilot light is extinguished, which includes a bi-metallic member subjected to the heat of the pilot flame for moving a stop into and out of obstructing position with respect to a projection carried by the stem of the gas valve.

Another and further object of the present invention is to provide a safety device for a gas fired space heater in which the stem of the gas control valve is provided with a projection, and which device includes a stop movable into and out of obstructing relationship with respect to said projection in accordance with the existence or non-existence of the pilot light flame.

A further object of the invention is to provide a safety device applicable to a gas fired space heater which adds not more than $1.00 or $1.50 to the retail price of a heater, so that a heater equipped with such a device may be purchased by a person of modest means to provide a gas heater for his humble abode.

Generally speaking, the safety device of the present invention contemplates the provision of a projection on the stem of the gas control valve, a stop member movable into and out of obstructing position with respect to the projection, and thermo-responsive means subject to the existence or non-existence of the pilot light flame for. moving the stop out of or into obstructing position so that when the gas valve has once been closed and the pilot light is extinguished, the valve cannot be opened until the pilot is again lighted.

The above, other and further objects of the present invention will be apparent from the following description and accompanying drawings.

The accompanying drawings illustrate embodiments of the present invention, and the views thereof are as follows: 7

Figure 1 is a fragmental view, partially in plan and partially in section, of a portion of a com-' bustion chamber of a space heater equipped with a. heating unit comprising several gas burner tubes and provided with the safety device of the present invention, showing in full lines the arrangement of the parts when the stop is in obstructing position and in dotted lines the position of the parts when the stop is out of obstructing position.

Figure 2 is an elevational view of certain of the elements entering into the device of the present invention, showing the relationship of certain of the parts.

Figure 3 is a fragmental view, partially in plan and partially in section taken along the line III-III of Figure 2, showing in full lines the position of the thermo-responsive means in relation to the pilot when the pilot flame is extinguished, and in dotted lines the displaced position of the therrno-responsive means.

Figure 4 is a view similar to Figure 3, and in addition shows the relation of a portion of a second thermo-responsive means operable by the burner flame to augment action of the first thermo-responsive means for movement in one direction, the full line position being that occupied by the parts when the pilot flame is existent, and the dotted line position that of the parts when the pilot flame is extinguished.

Figure 5 is a fragmental elevational view of a space heater casing showing an opening therein through which the position of the movable stop of the present invention may be observed.

Figure 6 is a view, partially in front elevation and partially in vertical section, looking at the inlet end of a combustion chamber of a space heater, equipped with the device of the present invention, and showing the supply pipe, valve tion indicating the position occupied by certain of the parts when the pilot flame is existent and the stop is moved out of obstructing position.

Figure 7 is an elevational View of a gas valve arranged with its valve member rotatable on a vertical axis and its handle swingable horizontally, and showing the safety stop in obstructing position.

Figure 8 is a view, partially in end-elevation and partially in section, of the arrangement of Figure '7, taken at 90 degrees from the position of Figure 7.

The drawings will now be explained.

In Figures 1 and 6, the lower portion of a combustion chamber is designated generally as A and is of usual sheet metal construction with side walls I and 2. The lower extremities of the side walls I and 2 are shown as inturned at 3 and 4, with their confronting margins bent upwardly at 5 and B forming flanges arranged in spaced relation and defining a space into which the tubes 1, constituting the burner B, project. The burner B includes the vertically extending open-ended tubes I and a horizontally extending header 8 which receives a supply of gas from the pipe 9 through an elbow connection ID. The burner B is held in place by means of straps II and I2 suitably bolted at I3 and I4 to the side walls I and 2 of the combustion chamber and to the header 8, as may be observed in Figure 1.

The combustion chamber A has a front wall I5 which may be integral with the side walls I and 2. From Figure 4, it will be observed that the bottom of the combustion chamber, defined by the inturned portions 3 and 4 of the side walls, is above the header 8 and the pipe 9. A pilot C is arranged at the front of the row of tubes 1 so as to be accessible through the door I6 of the heater casing D, for the purpose of lighting the pilot in the event the flame is extinguished.

A gas valve E communicates with one end of the pipe 9 and also with a supply pipe I! through which gas is supplied to the burner B. The valve E is of known construction and preferably has a tapered plug valve member cooperating with a tapered seat formed inwardly of the valve body, the valve member being apertured so that gas may pass through it when turned to one position and to shut off gas when turned to another position. The valve member is maintained in tight engagement with its seat by means of a. spring I9 surrounding a projection of the stem extending from the other side of the valve body, which spring is retained between a washer 20 suitably held on the stem, as by a cotter pin or other fastening means, such as screw threads.

The outer end of the stem I8 is supplied with a handle 22, so that the valve may be opened or closed as occasion demands. The stem is shown as provided with an integral boss 23 having a projection 24, the projection being illustrated as a wire extending away from the axis of the stem.

Secured to the inner portion of the side wall I of the combustion chamber is a bracket member 25 projecting upwardly, inwardly, and again upwardly, and having its upper end 26 disposed in the neighborhood of the pilot C. Hanging from this upper end 26 is a flat, elongated bimetal strip or member 21, with the lower or free end thereof terminating adjacent the upper extremity of the pilot. Welded or otherwise secured to the lower end of this strip is a rearwardly projecting connection 28 which supports a depending arm 29.

Swingably supported on the pipe 9 is a lever 30, pivoted at 3| to a strap 32 which surrounds the pipe. Thi lever is pivoted to swing in a horizontal plane with one end movable over and out of obstructing relationship with respect to the free end of the projection 24. Figure 1 shows in full lines the normal position of this lever in obstructing position and with the valve E closed to gas passage, in which position, the extension or projection 24 is below an inclined portion 2| of the lever 30.

The bi-metal member 21 is constructed with a modulus to function between temperature limits of 50 and 700? F. and is arranged to swing to the right, when the pilot flame is existent, to move the lever 30 to the dotted line position of Figure 1, in which position it is out of obstructing relation with respect to the projection 24, thereby allowing the gas valve to be opened or closed at will. The bi-metal member 21 is supported to lie along the length of the flame issuing from the pilot 0 so as to be readily responsive to the presence or absence of such flame.

Rearwardly supported from the wall I, by a prop 33, is a second bi-metal member 34 inclined along the burner and having a modulus of between 50 and 4:00 F. Attached to the free end of this second bi-metal member is a piece35 overlying the bi-metal member 21. The arrangement of the bi-metal members is such that when the pilot is lighted, the bi-metal member 21 will swing to the right, as viewed in Figures 1 and 6, thus swinging the lever 30 to its dotted line or unobstructing position, as viewed in Figure l. The second bi-metal member 34 tends to move to the left, when the pilot is lighted, to oppose movement to the right of the bi-metal member 21. However, the bi-metal member 21 is constructed to be stronger in action and so that the tendency of the bi-metal member 34 to move to the left .may be opened and closed at will.

does not hamper movement of the member to the right when the pilot flame is existent.

As long asthe pilot flame is existent, the lever 30 is maintained in the dotted line position of Figure 1; that is, out of obstructing relation With respect to the projection 24, so that the gas valve In the event the pilot light is extinguished for any reason, or if it has been ofi for a period of time and it is desired to start the heater, a person would ordinarily light a match, and when about to light the pilot open the gas valve so that gas will be supplied to the burner, and in the event the match or lighter should be extinguished before the pilot is lighted, gas accumulates in the combustion chamber and when the pilot is lighted, an explosion occurs. The present invention prevents such occurrence.

Whenever the pilot controlled by the device of the present invention is out or its flame extinguished, the bi-metal member 21 functions to move the lever 30 into obstructing position with respect to the projection 24 of the gas valve stem, and when the gas valve has been closed to gas passage, it cannot be opened until the lever 30 is moved away from obstructing position. The only way the lever can be moved is by lighting the pilot. Thus, to operate the burner, when the burner and pilot are off, the stop cook 36 is opened to by-pass gas to the pilot C, and the attendant applies a match or other ignition device to the pilot, igniting the gas issuing from the pilot. As soon as the bi-metal member heat to the low limit for which it is designed, it moves away from the vicinity of the pilot flame, thus displacing the lever 30 from obstructing position. The attendant may then open the gas valve, and the burner will be ignited from the pilot.

The construction is such that the lever 30 remains in unobstructing position as long as the pilot is lighted. Should the pilot become extinguished, the bi-metal member 21 will function to move the lever to the full-line position of Figure 1, which is the obstructing position. Should the valve be opened when the lever is moved to such position and then swung to closed position, the extremity of the projection 24 rides or cams on the slight incline 2|, provided adjacent the flag end of the lever 30, which causes the lever to snap away momentarily from its then position to enable the projection 24 to pass the stop and lie below it, as clearly observed in Figure 6. In this position of the valve stem, the valve passage is entirely closed to gas, even though the stem may be oscillated a slight amount.

In order to prevent bending of the lever 30 upwardly, when an attempt is made to open the gas valve while the pilot is extinguished, retention means, such, for example, as a hook 31, may be supplied. This hook may engage over a margin of the lever 30 to prevent it being raised by pressure applied underneath it by the projection 24. The hook is so related to the lever that the lever may swing between its full line and dotted line positions of Figure 1 without inconvenience.

In the event, when the pilot light is extinguished, the bi-metal member fails to function to swing the lever 30 to obstructing position, and the burner is still ignited, the bi-metal member 34 comes into play to swing to the left, as viewed in Figures 1 and 6, and to move the bi-metal member 21 and its connected arm 29 to the left, swinging the lever 30 to obstructing position, by reason of the link connection 38 between the arm 29 and the lever 39. The second bi-metal member 34 is supplied as an additional safety feature, making it subject to the heat generated by the burner to function if the bi-metal member 21, whichis responsive to the pilot flame, fails to function when the pilot is extinguished.

Referring to Figure 3, itv will be noted that the bi-metal member 21 is supported adjacent the pilot C and slightly ahead of it. When the pilot is lighted, the freeend of the strip 21 bends or moves away from the pilot flame, as shown in dotted lines, and against'the end piece 35 of the second bi-metal strip 34. The free end of the strip 21 occupies substantially the displaced position as shown, as long as the pilot flame exists. When the main burner is ignited, the heat thereof will tend to move the second bi-metal strip towards the burner tubes 1; that is, to the left as viewed in Figures 1, 3, 4 and 6, and against the bi-metal strip 21. However, as the strip 34 is less eflective than the strip 21, the strip 21 will not be curved towards the pilot as long as the pilot flame exists.

Figure 4 shows, in dotted lines, the movement towards the pilot C of the strip 21 occasioned by flexure of the strip 34 when the pilot flame is extinguished and the main burner flame exists.

Figures 7 and 8 illustrate the application of the present invention to a gas valve having a vertical stem which is oscillated by a handle movable in a horizontal plane. A gas valve G is interposed between the supply pipe I! and the header connection pipe 9 and has a vertically disposed stem 39 carrying a handle 40 at its upper end. The bracket 40 is secured to the pipe 11 by a band 4|. A link 43 is pivoted at 42 to the bracket 40 and is also connected to the link 38 which is operatively connected to the bi-metal strip 21. The link 43 has a notch 44 in it adapted to hook with a lug-like part 45 of the handle 40.

When the link 43 is hooked to the part 45, the.

valve G cannot be opened to gas passage. The link 43 is operable by the bi-metal strip 2'! in the same manner as the lever 30, and for the same purpose.

The end of the lever 33, adjacent the peep hole 50 in the casing D, is bent to provide a target or sight 5| which is visible through the hole when the pilot is extinguished and is out of sight while the pilot flame is burning.

It will be noted that the elements entering into the device of the present invention are metallic parts made from inexpensive material, with a minimum of labor for manufacture and assembly, so that the complete device may be put on the market for sale at a low price.

The invention has been described herein more or less precisely as to details, yet it is to be understood that the invention is not limited thereby, as changes may be made in the arrangement and proportion of parts, and equivalents may be substituted, without departing from the spirit and scope of the invention.

The invention is claimed as follows:

A safety device for fluid fuel burners comprising a main burner, a pilot burner adjacent the main burner and adapted to ignite fuel flowing therefrom, a main burner fuel supply pipe, a main valve in said pipe for controlling the fuel supply to said main burner, a by-pass pipe extending from the main supply pipe around said valve to said p'ilot burner for controlling the fuel supply to the pilot burner, means for operating said main valve, said main valve having a stem provided with a projecting portion, thermo-responsive means actuated by heat from the pilot means to close the valve, and a second thermoresponsive means actuated by the heat from the main burner flame, said first and second thermoresponsive means each being connected to a common support and having free ends in normal spaced relation, said second thermo-responsive means operatively engaging said first thermo-responsive means for moving said locking device into the path of the valve stem projection when the pilot burner flame is extinguished and said first thermo-responsive means fails to function.

HUGH L. COLE.

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