US2493702A - Safety thermal gas-flow control - Google Patents

Description

Jan. 3, 1950 w. s. THOMPSON SAFETY THERMAL GAS-FLOW CONTROL Filed Nov. 17. 1948 s m m mw m 1 M Mm 1 I W 1 M 5 fi I I 1 6 M A 2,? Y Z 8 33 a m h a, +M F 9 m 3 r07 7 Z 5 M B 9 3 Z 4 3 4 v w w WMZ Patented Jan. 3, 1950 UNlTE D STATES PATENT oFncE William S. Thompson, Oklahoma City,- Okla. Application November 11, 1948, Serial No. 00.49:

6 Claims. (CI. int-117.1

My present invention relates to the general class of gaseous and liquid fuel burners of the thermostatically controlled and'automatically cutoif type, and more specifically to a safety thermal gas-flow control, which while well adaptedfor use with "various kinds of burners, is especially designed for use with a gas heating stove for automatically controlling the flowof fuel gas thereto. The primary object of the invention is the provision of asafe and sanitary heat-responsive and unitary fuel control m'echanism that is of small and compact arrangement for combination with a burner of this type of stove, by means of which the flow of gaseous fuel may be automatically cut oil in the event of a temporary loss of pressure in the main pipe line and burner, and also cut oil. in the absence of the flame from a burner due to accidental extinguishing of the;

flame from one of various causes.

As a unitary attachment for. a, heating stove, the control mechanism includes a minimum number of parts that may be manufactured with facility at low cost of production, and the parts may be assembled with convenience, for installation with the stove, to insure an appliance that is durable, reliable, and simple in construction and operation.

The invention consists in certain novel combinations and arrangements of parts'as will hereinafter be described andmore particularly pointed out in the appended claims.

In the accompanying drawings I have illus-v trated a complete example of a physical embodiment of my invention in which the parts are combined and arranged in accord with one mode I have devised for the practical application of the principles of my invention. It will however be understood that various changes and alterations are contemplated and may be made in these exemplifying drawings and mechanical structures, within the scope of my claims, without departing from the principles of the invention. While the drawings disclose a unitary structure adapted for use with a heating stove, I have also depicted an auxiliary pilot-appliance for selective use with a hot water heater, a floor furnace or other heating appliance, where the main flow of fuel is under control of the thermal unit in my control I mechanism. r

Figure 1 isa vertical sectional view of the appliance of my invention combined with theburner unit of a heating stove, and illustrating also the optional auxiliary pilot unit.

Figure 2 is a front fac view of the control box or cabinet; and

' posed valve stem Figure 3 is a detail view partly in section of the trigger or latch mechanism of the thermal unit. 'In carrying out my invention, the operating parts of the mechanism are enclosed within a cabinet or box I in convenient position to the stove, part of which is indicated'by the letter S' in Fig. 2.

A supply of gas is fed through a pipe line 3 that is connected to a usual main, and the pipe line, that extends through the top of the box to its interior, is equipped with a regulator casing 4 having an interior adjustable valve with its stem 5 projecting through awall of the box. The valve stem is provided with an exteriorknob 0r handle 6 and 'apointer or hand 1, so that the valve may be turned to 011', Low, High, or Danger positions, as indicated on the front face of the box in Fig. 2.

Below the regulating valve casing, the feed or supply pipe 3 is connected at the upper end to an upright valve casing I, and the lower end of the valve casing is connected by an elbow Joint 9 with a conventional burner or pipe Ill having usual multiple burner tips or jets l I located within the heating chamber of the stove B.

By means of I tition P the valve casing is divided into dual chambers, l2 for inlet of gas, and I3 foroutlet of gas, that communicate respectivelywith the feed or supply pipe and the burner pipe, as shown. v

outlet chambers a manu- Between the inlet and ally controlled gas flow control valve H is pressed by spring l5 to'resiliently close a valve seat or port in the partition, and the horizontally dis.- IB is reciprocably mounted at one end in a bearing or plug nut l1 exterior of the casing. The other shorter end of the springpressed valve-stem is slidably mounted with its.

spring I5 in a plug nut l'la, so that the valve may be longitudinally shifted to open position against the tension of the spring, and when released the spring pressed valve may automatically close its seat and cut oil the supply of gas from the inlet chamber to the outlet chamber.

For opening the initially pressed control valve preparatory to lighting or igniting the burner tips, a control and lighter lever l8 located withlnthe box, is pivoted at its lower end at I9 on a bracket 20 rigidly mounted, as by screws, on the plug nut l1, and the upper end of the pivoted lever is provided with an angu-,

, having corner legs 2, and located.

an integral upright angular parclosed resiliently The latch lever 24 is resiliently held in opera tive position by means of a spring '29 that connects the latch with the control lever, and the latter is fashioned with a lug 33 that co-acts with a detent or hooked jaw 31 on the free end of the latch.

After proper adjustment of the control valve,

and lighting of the pilot burner tips or jets, the

desired flames are emitted from the burner tips for heating purposes, and a thermal unit, responsive to heat from the flames is provided which, during absence of heat from the burners as when the gas pressure is cut off or the burners are accidentally extinguished, automatically causes closing movement of the control valvefor cutting off communication between the inlet and outlet chambers of the valve casing.

As here shown the thermal unit includes a bar or rod 32 preferably of Invar or other sutable material having practically no expansion or contraction co-eflicient with temperature changes, and an enclosing tube 33 of copper, which may be coated or plated with chromium to resist oxidation and corrosion at high temperatures, and which has a relatively high co-eflicient of expansion and contraction with temperature changes.

At is inner'end the tube is threaded into a nipple 34 of the valve casing 8, and at its outer 1 end where it projects over a portion of the burner and is subjected to heat from the flames of the burner tips, the tube is closed by a cap nut 35, and the rod or bar 32 is secured to the cap by a screw 35a, thus rigidly uniting the outer ends of the bar and the tube.

In Fig. l the valve I4 is open, and, provided the regulator casing 4 has been opened, the burner tips are lighted, and heat from the flames will expand the thermal unit 32-33.

This action will automatically close the control valve l4 and open the control valve 33, and the latter valve will then furnish the sole source of fuel flow, to the burners.

Should the gas pressure through the valve casing be cut off, or, in the event the flames are accidentally extinguished as by a draft, the positively opened control valve 33 will be closed by contraction of the thermal unit and thus deprivethe consuming device of its fuel.

Thermal tube 33, which is preferably provided with heat-dissipating fins 38 at the exterior of the box, is also provided with a slot withinthe end on pin 25, is mounted for spring 23 swings the lever free from the valve stem, and spring I! closes the control valve 14.

The expansion of the thermal unit. which results in closing the control valve l4, at the same time opens the control valve 33 that is located below the control valve and adapted to seat in a port of the partition P. As the valve 33 is opened by expansion of the thermal unit the pin 31 will engage the pin 33 on the lever 24. As the valve is further opened the lever 24 will be disengaged from the lug permitting the spring I! to close the lighter valve l4. At this time fuel is only passing to the consuming device through the valve 33. Thus, with loss or absence of gas pressure or a consuming flame, this thermal operated control valve is automatically closed by contraction of the copper tube 33 due to absence of heat from the burners.

The control valve 33 in the shape of a face disk is rigidly, mounted on the bar 32 at the outlet side of thepartition P, and it is cupped or dished internally and provided with a semi-flexible face disk which affords protection from damage to the partition P due to further contraction of the thermal unit under extremely low temperatures.

After the lighter valve is closed, the control valve is held in open position for flow of the gaseous fuel from the inlet chamber, past the open thermal valve to the outlet chamber, and thence to the burners.

While the control valve 14 is closed, and the stove is heating with flow of gas through the open thermal controlled valve, in order to turn off the flow and to extinguish the flames, the regulator valve 4 is turned to Off' position. This action and movement restores the valve 33 to its seat in the partition, due to contraction of the thermal unit. Thus, while the stove is heating, should the pressure or flow of gas cease. or should the flames accidentally be extinguished, the cooling thermal unit automatically contracts and closes the thermal operated valve. 4

In some instances, where a pilot burner is desirable, the automatic control mechanism may be provided withan auxiliary by-pass device and pilot burner for the burner. For this purpose a small pipe 43 is connected with the main pipe 3, exterior of the box and exterior of any conbox, that permits movement of a pin or screw 9 31 that is threaded in the bar 32 and projects upwardly throughthis slotinto, position for coaction with a second pin 33 rigidly mounted on the latch lever 24.

Thus, after the burner is lightedwith a gas flow through the open control valve l4, the thermal unit, due to heat from the flames of the burner, actuates bar 32, pushes pin 31 against pin 33 to release the latch from the lever i3,

ventional thermostatic valves, and this pipe 43 projects into the box and is connected with an auxiliary valve chamber or casing 4! attached to the main valve casing. o

The casing 4| is provided with an interior partition having a valve seat that is controlled by a tapered valve 42 having a stem 43 that is coupled to the innerend of the thermal rod 32 within the inlet chamber l2, and a spring 44 tends to hold the valve in its seat. when the pilot valve is opened by operation of the thermal rod, the .pilot gas flows through pipe 45 to the pilot burner 46.

This detachable and auxiliary pilot device is in the nature of 'a stand-by to furnish flame for holding the thermal valve open, and for re-lighting the main burner when flow is restored by an exterior or foreign room temperature thermostat, and it may be used with, or omitted from the safety thermal gas flow control appliance of my invention, depending upon the character of stove, furnace, or heater. when employed with the appliance ofmy invention the auxiliary pilot burner is positively cut off with the appliance in the event of failure of the flame or of the gas Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a thermal gas flow control mechanism for a stove the combination with a burner, provided with a valve casing having a chamber, a partition in said chamber dividing the same into two compartments and said partition having spaced valve seats, with a fluid fuel supply pipe connected to one compartment of the chamber, and the burner connected to the other compartment of the chamber, of a manually opened biased closed gas flow control valve engaging one of said seats, a thermal tube carried by said casing and connected to the compartment of the chamber connected to the burner, a thermal rod on said tube and extending into both compartments of said chamber a second control valve for the other seat on said thermal rod and in opposed relation to said first control valve, said tube and thermal rod being thermally responsive to the burner, manually operatedmeans for opening the first control valve, latch mechanism for retaining the first control valve in open position, and release mechanism actuated by the thermal responsive action of the burner on the tube and thermal rod to permit closing of the first control valve and the operation of the valves permitting fuel to be admitted to the burner when the second valve is open and the first valve is closed.

2. The invention as in claim 1, wherein means -is provided for resetting the release mechanism.

3. In a thermal control mechanism for a gaseous fuel burner the combination with a valve casing having a chamber, a partition in said chamber dividing the same into two compartments and said partition having spaced valve seats, with a fluid fuel supply line connected to one compartment of the chamber and the burner connected to the other compartment of the chamber, of a control valve for one of said seats, a thermally responsive control means operatively carrying said valve so that the action of said valve is responsive to the burner, a spring closed gas flow control valve for the other seat in opposed relation to said first valve, a stem for the second valve, a manually operated lever for coaction with the stem to open the second valve, a spring retained latch member having a detent coacting with the lever, and latch release mechanism actuated by said thermally responsive control means for actufating the latch member to release the lever so that fuel will be admitted to the burner when the second valve is closed and the first valve is open.

4. The invention as in claim 3 wherein said latch release mechanism includes a push pin movable with the first valve and a co-acting pin rigid with the latch.

5. In a thermal control mechanism for a gaseous fuel burner, the combination with a valve the control valve in open position and release mechanism for the latch mechanism, of a valve means for the other seat in opposed relation to said control valve and thermally responsive to the burner, and said valve means comprising a valve,

a thermally responsive bar forming a valve stem for the valve, a thermal responsive tube on said bar and actuating mechanism coacting with said bar and latch for releasing the control valve after the valve of said valve means is opened so that fuel will be admitted to the burner. when the control valve is closed and the valve of said valve means is open.

6. The invention as in claim 1 wherein said control valve is provided with a r'eciprocable stem, and said manually operated means comprises a lever which is adapted for coaction with the stem in opening the control valve, and said latch mechanism comprising a pivoted latch engaging the lever, a spring connected to said latch and lever for urging the latch and lever toward latching position, a reset pin on the latch, and coacting pins on the bar and latch comprising the release mechanism for releasing the latch under opening movement of the valve of said valve means and its bar or stem.

WILLIAM S. THOMPSON.

No references cited.

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