US1791530A - Safety valve for gas burners - Google Patents

Description

Feb. 6, 1931.

C. H. MORROW SAFETY VALVE FOR GAS BURNERS Filed April 16, 1928 ea re. 1

omen H. MORROW, 0F CLEVELAND, OHIO, ASSIGNOR TO THE HOTSTREAM HEATER 'CQMPANY, 0F CLEVELAND, OHIO, A CORLPOBATION OF OHIO I SAFETY VALVE FOR GAS BURNERS' Application filed April 16,

This invention relates to thermostatic valves for use in connection with gas burners having pilot lights, and the invention has particular application to domestic hot water eating installations of the storage type wherein a pilot light is arranged for normally continuous operation, a main burner is arranged for intermittent operation dependent on conditions within the hot water tank, the pilot light serving to ignite gas admitted to the main burner, and being usually capable of maintaining water standing in the accomplish the above described arrangement tank at the temperature to which it has been raised by the main burner after the same has been shut off 'by the thermostat.

Such a system is illustrated and described more in detail in my copending application Ser. No. 261,160, filed March 12, 1928.

In such usual installations, should the pilot light he accidentally extinguished gas may be admitted by the thermostat to the main burner up to the capacity of the supply line and without ignition, resulting in a very dangerous condition in the installation as well as involving a continuous wastage of gas until the condition is discovered.

The object of my invention is broadly to provide a means for cutting off gas supply to the main burner as the pilot flame is extin uished.

ore particularly m invention comprises the PIOVlSlOIl of asupp ementary valve in the main burner line, a pilot flame controlled thermal element adapted to maintain the suplementary valve open dependent upon com ustion at the pilot, the parts being so arranged that the supplementary valve is allowed to close as by a spring immediately upon extinguishing of the pilot flame, and whereby the valve will remain closed regardless of subsequent temperature conditions in the system, until reset to allow reestablishment of the pilot flame.

For this urpose I provide a stop in the casing and inkage cooperable therewith and associated with the valve and the thermal element, whereby the valve is maintained open until extinguishing of the pilot flame, the linkage being arranged to be disassociated how the stop by the element upon extinction 1928. Serial No. 270,485.

of the flame, whereb the valve is allowed to be closed by the spring, the parts being also so arranged that resetting thereof by hand is necessary for reassociating the stop and linkage to reopen the valve.

A further object of my invention is, therefore, to so arrange the supplementary valve and the pilot thermostat control thereof that once the valve is closed it cannot be reopened except by hand manipulation of the apparatus.

Still another object of the invention is to with the utmost simplicity both of structure and of operation. A further object of my invention is to provide a structure which combines the functions of pilot burner and pilot thermostat.

The exact nature of the invention together with further objects and advantages thereof will be apparent from the following descrip-- tion taken in connection with the accompanying drawings in' which Fig. l is a view in elevation largely in section showing my invention as incorporated in a water heating system of the type described the parts being shown relatively positioned as with the pilot burner functioning; Fig. 2 is'a generally vertical section as in the vertical planes. of line 2-2, Fig. 1; Fig. 3 is a horizontal view as in the planes of line 3-3, Fig. 1.

With reference now to the drawings, 1 is a jacket surrounding the hot water tank of the system; 2 is a casing secured with the jacket 1 as by bolt 3.

The casing 2 has an inlet opening 4 threaded as indicated for connection with a ipe 5 through which gas is supplied, pre erably subject to a valve shown diagrammatically at A and thermostatically controlled dependent upon temperature of water in the tank, as by thermostat B. The casing 2 also has an outlet opening 6 threaded to receive a pipe 7 arranged to deliver gas to the main burner of the system. The casin 2 is also provided with a wall 8 dividing tl e interior of the casing into two chambers: 9 in communication with the supply opening 4 and 10 in communication with the delivery opening 6. The wall 8 has an opening 11, and a valve 12 is arranged to seat upon the wall 8 to close this opening and thus cut off communication between the supply pipe 5 and the delivery pipe 7. This valve 12 has a stem portion 13 slidable in a bore 14 in a cap 15 which forms a closure for the chamber 9 of the casing. A spring 16 is arranged in an annular groove in the cap 15 to bear against the valve 12 and yieldably urge it to closed position.

The valve 12 has another stem portion 17 projecting into the'chamber 10 of the casing.

Extending through the chamber 10 and mounted in the casing 2 for rocking movement is a shaft 18 which carries without the casing a handle 19 and within the casing a split crank 20 secured therewith as by a cotter pin 21, the shaft conveniently having the threaded and dead ended casing bearings as indicated. The free end of the crank 20 carries by means of a pin 22 a link 23. The free end of the link 23 carries a bearing stud 24 preferably having a square head; the members 18, 19, 20, 23 comprising a linkage as will follow.

Seated for sliding movement in a suitable opening in the casing 2 is a rod 25 one end of which is adapted to bear against the head of the stud 24. The opposite end of the rod 25 is secured as by the threaded connection indicated with the outer end of a tubular member 26 whose medial portion clears the rod 25 to form an annular chamber 27 thereabout and whose inner extremity is secured with the casing as by the threaded connection 28, the tubular member 26 and rod 25 therewithin passing through a suitable opening in the jacket 1. Adjacent the inner end of the member 26 the casing 2 is counterbored to form an annular chamber 29 which thus communicates with the chamber 27. The

chamber 29 is adapted to be arranged in communication directly with the pipe 5 above the valve A as by piping 30 and a cross bore 31.

The rod 25 near its outer end has a cross bore 32 connecting with a longitudinal bore 33 whereby passage is had from the annular chamber 27 to the open extremity of the member 26. L

The members 25 and 26 are of materials having difi'erent coeflicients of expansion, that of the member 26, which may be of copper having a higher coeflicient than that of the rod member 25 which may be of iron; so that the inner extremity of the member 26 being secured with the casing 2, the outer extremity of the members being secured together and the inner extremity of the member 25 being free to move in the casings the position of the end of the member 25 extending within the chamber 10 is dependent upon the mean temperature of the two members.

Secured in the casing 2 and extending within the chamber 10 adjacent the stud 24 and corresponding end of the rod 25 is a post 34 having a square edge immediately adjacent the near edge of the stud.

Operation will be as follows, assuming the pipe 5 in communication with a gas supply, the pilot being lighted and the thermostatic parts, therefore, warm, these conditions being illustrated in Fig. 1. The spring 16 maintains the valve 12 with its stem portion 17 hearing against a heel portion 35 of the link 23. The stud 24 bearing upon the post 34 limits motion of the stud end of the link 23 to that of advancing the stud 24 to bear against the rod 25, this movement being generally about the pin 22 of which is under these conditions substantially stationary. The thermostatic elements being warm the position of the end of the rod element is such that the valve is maintained open so that gas may flow practically freely through the casing 2 between the pipes 5 and 7 and thence to the main burner.

Gas passes at all times to the pilot flame by way of the pipe 30 and bore 31; thence through the annular chamber 27, cross bore 32, bore 33 and out the open end of the member 26 which thus forms a pilot nozzle operating independently of the valve A and supplemental valve.

Without the pilot flame the parts 25 and 26 quickly cool and owing to their different coefficients of expansion the end of the rod 25 projects increasingly into the chamber 10 until it pushes the stud 24 from its position of rest upon the post 34 which allows the stud to drop downwardly. This frees the crank 20 allowing the spring 16 to close the valve rotating the crank in a clockwise direction Fig. 1.

Should the thermostatic valve A thereafter open the supply to the pipe 5 the valve 12 will remain seated so that the main burner will receive no gas.

\Vhat I claim is:

. 1. In a device of the class described, agenerally hollow caslng having an opening adapted for connection with a gas supply line and an opening adapted for connection with a delivery line for a main gas burner, valve means in said casing arranged to control communication between the openings thereof and normally tending to cut off said communication, a thermally responsive element associated with said casing, a pilot burner associated With said element, said element being movable relative to said casing dependent upon maintenance of the pilot flame, link means arranged in said casing between said valve and said element for cooperation therewith, and a support in said casing for said link means. said link means resting upon said support during maintenance of' said pilot flame and said valve being thereby held open, said link means being freed from said support by said element upon extinguishment with a delivery line for a main gas burner,

valve means in said casing arranged to control communication between the openings thereof and normally tending to cut ofl said communication, a thermally responsive element associated with said casing, a pilot burner associated with said element, said element being movable relative to said casing dependent upon maintenance of the pilot flame, link means arranged in said casing between said valve and said element for cooperation therewith, a support in said casing for said link means, said link means resting upon said support during maintenance of said pilot flame and said valve being thereby held open, said link means being freed from said support by said element upon extinguishment of said pilot flame, whereupon said valve is allowed to close, and means for moving said link means to a position of rest upon said support upon reestablishment of said pilot flame, whereupon said valve is again held open.

3. In a device of the class described, a generally hollow casing having an opening adapted for connection with a gas supply line and an opening adapted for connection with a delivery line for a main gas burner,

valve means in said casing arranged to control communication between said openings thereof and normally tending to close to cut off said communication, a thermally responsive element associated with said casing, a pilot burner associated with said element, said element being movable relative to said casing dependent upon maintenance of the pilot flame, a crank pivotally mounted in said casing, a link pivotally mounted on said crank and arranged between said valve and said element for cooperation therewith, and a able relative to said casing dependent upon maintenance of the pilot flame, a crank pivotally mounted in said casing, a link pivotally mounted on said crank and arranged between said valve and said element for cooperation therewith, a support in said casing for said link, said link resting upon said support during maintenance of said pilot flame and said valve being thereby held open, said link being freed from said support by said element upon extinguishment of said pilot flame, whereupon said valve is allowed I to close, and means for operating said crank to move said link to a position of rest upon said support upon reestablishment of said' pilot flame, whereupon said valve is again held open.

In testimony whereof I hereby affix my signature.

CLARENCE H. MORROW.

support in said casing for said link, said link resting upon said support during maintenance of said pilot flame and said valve being thereby held open, said link being freed'from said support by said element upon extinguishment of said pilot flame, whereupon said valve is allowed to close.

, 4. In a device of the class described, a generally hollow casing having an opening adapted for connection with a gas supply line and an opening adapted for connection with a delivery line for a main gas burner, valve means in said casing arranged to control communication between said openings thereof and normally

Images