US2080385A - Automatic safety shut-off fob - Google Patents

Description

y 937- o. CONGDON 2,080,385

AUTOMATIC SAFETY SHUT-OFF FOR BURNERS Original Filed Oct. 1, 1929 awuantoz' Patented May 11, 1937 UNITED STATE AUTOMATIC SAFETY BURNERS Oliver Congdon, Brooklyn, N. Y.

SHUT-OFF FOB Application October 1, 1929, Serial No. 396,456 Renewed October 20, 1936 6 Claims. (01. 158-1171) Thisinvention relates to a means for shutting off the fuel supply or heating medium of a burner or heater upon the same ceasing to function accidental'ly and to thus prevent the passage or 5 escape of said fuel or heating medium and particularly relates to improvements in the heat responsive element of a device for thepurpose just stated whereby said eleinents rapidity of action and efficiency is increased. It is especially suited 10 to be used with the burners of gas stoves or heaters, tho not necessarily limited to such use, and when so used it eliminates the danger that exists with the ordinarytype of burner should the gas supply be temporarily shut off or the 15 flame accidentally blown out, as the gas cannot escape after such an occurrence. In the accompanying drawing two forms of my device are shown, but it should be understood that various modifications can be made within the scope of 20 the invention as defined by the claims in order to adapt it to different types of burners or furnaces employing various kinds of heat developing means.

In the drawing 25 Fig. 1 illustrates a side view'of one form of my invention,

Fig. 2 illustrates a plan view of the form of device shown in Fig. 1, and

Fig. 3 represents a plan view showing the ap- 30 plication of my invention to a slightly diiferent type of burner.

In Figs. 1 and 2, It) indicates the pipe or conduit thru which the fuel is conducted and this pipe is shown as fitted with a valve I5 to shut 35 ofi the fuel supply or to regulate the quantity. The fuel, after passing the valve l5, goes to the safety shut-off valve 20 and then to the burner 5. The valve 20 is normally closed by a spring 2| and must be forcibly held in an open 40 position in order to allow the passage of the fuel to the burner. It is provided with a lever 23 for ,its manual operation and with a suitable arm 22 which arm turns, when the valve is open, to a position where itcan be engaged by the end 45 of the heat responsive or deformable element 8.

This element is shown as supported at one end by J a connection to the burner and curves around the burner with its free end adjacent to the shut-off valve 20. It consists of a piece of curved flat ma- 5 terial with its outer edge flanged or made thicker at an angle to the plane of the surface of the ma terial, this thickening being provided in the present instance by the edge being turned down to give the material and; section with this turned, down 55 edge at such a distance outside the burner that it is not subject to as much heat as the inner curved edge that is near the burner. Between this inner edge of the element and the outer turned down edge is arranged a series of perforations 9 to prevent the heat of the inner edge of the element from being transmitted to the'outer turned down edge as readily as if solidmetal were used and to allow a slight movement between the inner and outer edges without stretching as much metal as would otherwise be the case. The free 10 end of this element v8 is extended to a point where it is very close to the arm 22 on the valve 2!] when the valve is moved to its open position and the parts cold. When, however, the valve is moved to this open position and the burner is put into operation, the inner edge of the deformable element 8 is rapidly heated with the resuit that the element tends to straighten out, as shown by the dotted lines, as the outer edge receives comparatively little heat and, when this occurs, the extreme end of the element engages the lever 22 on the shut-off valve 20 and holds the valve open, notwithstanding the spring 2!,

' as long as the burner is in operation. Should,

however, the flame be extinguished, from any 25 cause, the inner edge of the element -8 would contract to its normal size and the free end of the element 8 would move outwardly to aposition where it would clear the lever 20 on the shutoff valve so that the valve would, then be free to be turned by the spring 2! to a position where the fuel supply is shut off and cannot escape thru the burner until the valve 20 is again forcibly brought to its open position. It will thus be noticed that an exceedingly simple means is provided by my invention for preventing the escape of the fuel when the burner ceases to give out heat and that the fuel cannot be made to escape unless it is purposely intended to have it do so by holding the valve open. The valve I5 is provided in order to manually shut off the fuel supply and to enable the same to be regulated. It may obviously be placed in the position shown or between the automatic valve and burner, this being simply a matter of preference, as the effect is the same in either case. The movement of the end of the element 8 that locks the valve 20 occurs very quickly upon the burner being put in operation so that it only is necessary to hold the valve open a very short time when it will be locked open and remain so until the burner ceases to function. It should be understood that the type of burner and shut-off valve shown herein is illustrated in order to show the principle and operation of my device and that my device is not limited to this particular form"= of burner and shut-oil valve. i\

In Fig. 3, It, as in Figs. 1 and 2, represents the fuel supply pipe, 20 represents the automatic shut-off valve, 2] the spring to normally close'the valve, 23 the valve operating handle, 22 the valve locking lever, 5, the burner, and 8 the deformable heat-operated element. In this. figure the valve I5 has been omitted, the fuel supply to the burner being shut on or ofiby means of the automatic shut-off valve 20. It is intended that, in order to shut oil the fuel supply when it is desired to extinguish the burner, the deformable element be sprung downward by a slight pressure to clear the end of the lever 22, so that thelever can slide over the top of that element and allow thevalve to close, thru the action of the spring 2|, even tho the burner is in operation and the element is expanded to its locking position. The element is, in this case, a straight piece of material with a turned down edge at asuflicient distance from the burner to receive a smaller part of the heat thereof than the part of the flat edge of the element that is nearer to the burner flame. The element is provided with a series of holes 9 between the expanding edge and the turned down edge so that it would be caused to bend as soon as the edge near the burner has been heated, and thus to move the end of the element adjacent to the valve 20 to engage the lever 22 and hold the valve open; The deformable element is supported by the burner or other suitable part at its opposite end to that engaging the valve lever 22 and the end which acts on the valve lever 22 is caused to move with considerable speed to lock the valve open once the burner is put into operation.

It should be understood that, while my invention is particularly suited for use in connection with gas burners, in order to prevent danger and loss from the escape of gas if the flame is accidentally extinguished, or for use with oil burners,

in order to prevent the loss of oil or otherunde: sirable effects thru the flow of the same should the burner go out accidentally, it is not necessarily limited to such use, as it maybe employed to automatically prevent the possibility of reheating an element or furnace once it has ceased to functionwithout such re-heating being started up by the manual operation of the shut-01f device.

Having thus, described my invention I claim as new and desire to secure by Letters Patent:-

1. In a safety device for heaters,-the combination of a pipe to conduct a heat producing fuel thereto,'a valve in said pipe to control the passage of said fuel, a spring to normally move said valve to its shut-off position to prevent the pase of said fuel thru said pipe, and means, comprising a deformable element with one edge positioned to receive the heat developed at said heater and another edge relatively distant from said heated edge and being turned down to extend below the heating portion of said heater whereby, when said heater is in action, said turned down portion is relatively cool while said first mentioned edge is hot and said deformable element is deformed and said valve is held open against the action of said spring, and whereby, should said heat cease to develop, said deformable element assumes its normal shape and said valve is released and the passage of said fuel to said heater is shut off thru the operation of said valve by said spring connected thereto.

2. In a safety device for heaters, the combination of a. conductor for transmitting a. heat producing means thereto, a control means to regulate the passage of the heat producing means thru said conductor, means for operating said control means to bring said control means to a position in which said control means prevents the passage of the heat producing means thru said conductor, and means, comprising a deformable element of a homogeneous material with one edge positioned to receive the heat developed at said heater and another edge relatively distant from said heated edge and being provided with a flange to make said latter edge relatively thick at right angles to the plane of said element, whereby,,when said heater is in action, said flanged edge distant from said heater is relatively cool while said first mentioned edge is hot and said deformable element is deformed and said control means is held against the action of said operating means, and whereby, should said heat cease to develop, said deformable element assumes its normal shape and said control means is released and the passage of said heat producing means to said heater is shut off thru the operation of said control means by its said operating means.

3. In combination with a source of heat, a deformable heat responsive element comprising a plane of the plate whereby said edge is relatively flexible on a line parallel with the plane of the plate and relatively rigid on a line at right angles to the plane of the plate.

4. A deformable heat responsive element comprising a strip of homogeneous material and having one longitudinal edge bent at an angle to the opposite edge whereby the heating of one edge to a higher temperature than the other will cause an edgewise flexing of said strip.

5. A deformable heat responsive element comprising an elongated member of homogeneous material having one longitudinal edge bent at an angle to the opposite edge, and having openings intermediate the two edges to reduce the transfer of heat from one edge to the other whereby the heating of one edge to a higher temperature than the other will cause an edgewise flexing of said member. 7

6. A safety device comprising the combination of a burner, a fuel supply pipe leading thereto, a spring biased valve therein, and thermally responsive control means therefor comprising an angle member of homogeneous material having one flange thereof positioned in heating relation to said burner, and having theother flange positioned out of direct heating relation to the burner, one end of said member being rigidly supported, and the opposite end being positioned to hold said valve in open position so long as

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