US2437163A - Gas valve safety shutoff - Google Patents

Description

`March 2, 1948. Y I E. R. KOPPEI. 2,437,163

GAS VALVE SAFETY SHUT-OFF Filed Jun 2, 1945 2 Sheets-Sheet 1 ...g "i n" Y Y v INVENTOR.

Ems! 2. Kappel Harney March 2, 1948.

E. R. KOPPEI.

GAS VALVE. SAFETY SHUT-OFF 2 Sheath-Sheet 2 v Filed June 2, 194s Patented Mar. 2, 1 948 GAS VALVE SAFETY SHUIOFF Ernst R. Koppel, Chicago, lil., assigner to A. O.

Smith Corporation, Milwaukee, Wis., a corporation of New York Y Application June 2, 1945,k Serial No.1597,263

A4 claims. (ci. isa-4111.1) i

This invention relates to a gas valve' safet shut oiT andhas been applied to pilot controls in thermostatically operated water heaters of the type in domestic use.

Thev principal object of the present invention A refers t9 flow 'ofgas to the maingas burner. f

is to provide a gas valve safety shut oil for/a pilot control that is absolutely positive.

Another object is to provide andinterlock between the main gas cock and gie-pilot push button valve so'that the latter# cannot be operated unless the cocklis in vpilot position.

Another objectsto provide a control which fails safe.

` These and other objects and advantages of the invention will appear in connection with the description of an embodiment of the invention illustrated in the accompanying drawing.

In the drawing:

Figure 1 is a front elevation of the control;

Fig. 2 is a side elevation; t

Fig. 3'is a vertical sectional view of Fig. 2 in which the main gas cock is at start position to permit flow of gasfrom the inlet to the pilot push button valve which is in depressedposition;

Fig. 4 is a section taken online 4- 4 of Fig. 3

vwith the push button depressed;

' The valve construction to vwhich the present invention is applied is similar to that found in the application of the present inventor illed August 14, 1941, entitled Safety pilot for heaters and issued to Patent No. 2,384,314 on October 4, 1945.

` In general, as shown in the drawings, the v-alve unit comprises a cast metal body Lhaving two mainA valve chambers, one for the gas cock or manual shut off valve 2 and the other for the'- thermostatically controlled snap valve 3.

A pilot burner 4 is threaded at its inner end into the casing I and a thermostat 5 extending parallel to the pilot burner tube I and above it is also threaded into the casing. The central rod 6 of the thermostat is connected to and operates valve 3. The thermostatic control is similar in general to present day standard thermostat controls used on the main burner for lwater heaters.

The hand shut off valve has a .handle I for turning it and is inscribed at three positions properly spaced apart with the markings om sta and on in the order named. "Pilot may be substituted for startff if desired. The marking off refers tothewmain shut ol valve 2 being in closedflposition. The marking on the 'valve 2 in open position to' permit The body'portion lof valve 2 is conical and has a radial passage 9 therein disposed to register with a gas linlet passage I0 when handle 1 is at on"'position as shown in Fig. 9 and to be v turned so as to fail to register with the passage Ill when handle 'I'is at ofi position as illustratedin Fig. 5. Passage 9 is always in registry with the-outlet passage II in the valve 2 and casing I.

Thefconical body I is also provided with an auxiliary passage I2 positioned to connect inlet passage Ill to passage I3 leading to pilot push button valve'll when handle 1 is at "start positionas shown'in Fig. 3.

The radial location of passage I2 relative to port 9 is such that when handle 1 is at start passage 9 is shut off from passage' I0 and passage I2 registers with inlet I0 and passage I3 leading .to pilot push button valve I4. Inlet passage III is closed to both passages 9 and I3 when handle 1 is turned to ofi position as illustrated in Fig. 5. The passage I0 is also open to passage I3 to allow gas to iiow to the push button valve Il when handle 'I is at "on" position. The ilow of gas to the pilot is therefore not interrupted in turning the gas cock valve 2 from start to "on position. When at on position the valve I4 is released to'shut oil flow of gas thereto from pas- .sage I3. Passage I8 still receives gas from' passage III butis inoperable to supply gas to the pilot burner at the'on position of handle 1.

The gas for the main burner passes through inlet I 0, passage 9, outlet II., and through valve l to pipe I! leading to the burner control valve. Both valve 2 and thermostatically controlled valve-'3 must be open to supply gas to the main burner. Since valve 3 is controlled by heat from I8 at its rear end. Thev body II has a longitudinal passage I! extending from its rear end to` a line near its forward end where connection is made by passage I9 with a passage 2li extending diametrically, through the valve body. Two radial passages 2I and 22 connect with passage I9 intermediate the rear end of body I1 and the passage 20. i

When push button I6 is depressed or pressed 0 inwardly as shown in Fig. 4, moving valve body .I1

l against spring I8, passage 20 is caused to register with a passage 23 leading from the gas supply passage I3 and with a passage 24 leading to the pilot burner 4. Both radial passages 2l and 22 are closed when button I6 is in depressed position` When pilot thermostat becomes heated and valve 3 snaps open button I6 can then be released. A needle valve 25 controls the volume of gas supply to the pilot burner 4.

When the pilot burner and the main burner are on, the radial passage 2I registers with passage 26 leading from the low pressure side of thermostat valve 3 and radial passage 22 registers with passage 23 which in turn connects with passage 24 leading to the pilot burner 4. At the same time passage is closed by the housing surrounding the'valve body I1.

Valve body I1 may be provided with a bleeder groove 21 intermediate radial passages 20 and 22 which alternately register with port 23. This groove is of such a length that it has only a small overlap narrower than the diameter of port 23. In transferring valve I4 from the depressed to the release position gas will bleed through groove 21 and since the overlap is not sufilciently wide the passages 20 and 22 will be open simultaneously momentarily to port 23, allowing for uninterrupted gas ow to pilot 4.

The actual operation of the valve structure described in co-pending application issued to Patent No. 2,384,314, previously referred to and need not be further described here.

Reference is made to the interlock between the main gas cock or shut off valve 2 and the pilot push button valve I4 to prevent operation of the pilot button I8 in the "on" and o position of the gas cock.

The interlock in general comprises a rod or interlock plunger 28 connected to a cam 29 on the underside of handle 1 of gas -cock 2 by a head 30 and extending horizontally from handle 1 within an opening in casing I to the pilot push button valve` I4.

The plunger 28 is provided with flange 3i intermediate the ends thereof and is spring loaded by spring 32 which is retained between flange 3i and the outer plate 33. Plate 33 also holds in place the body of the main shut-oil.' valve 2. The inner end 34 of plunger 28 is generally pointed and normally serves as a detent entering a transverse groove 35 in valve body I1 of valve I4 by reason of spring 32 biased against plate 33. In this` position of plunger 2B it is impossible to depress button I 6.

Cam 29 on the underside of handle 'I extends from the on positionof handle 1 to the "ctrll position through the start or pilot position thereof and operates to limit radial movement of handle 1 and the turning of valve body 8. In the operation of the interlocking device, head 30 of the plunger 28 rides in the cam track as the handie 1 is turned from the of! position toward the start position and is lifted against spring 82 by ram 29 when the "start position is reached. This pulls plunger 28 out of groove 35 in valve body I1 and permits button I8 to be depressed by the operator. A detent 38 may be provided at the center of the cam 29 to indicate the "start" position.

If the handle 1 of main valve 2 is then turned from start to "on position while the push button I6 4is held depressed, the plunger upon release of the push button is spring-pressed back into groove 35. locking the push button in released position.-

At the ofF' position of handle 1 the end 34 of plunger 28 also enters the groove 35 in valve body I1 interlocking the push button I6 in release position. It is therefore necessary in order to manually depress push button IB and permit the flow of gas to the pilot 4 from the passage I3. to turn the main valve 2 to start position.

Passage I3 in turn is in registry with passage I2 leading to highpressure inlet I0 when handle 1 is at either "start" or on position to carry inflowing gas to the push button valve I4. At the "on position push button I6 cannot be depressed from released position. Gas to the pilot is then flowing from the lower pressure side of thermostatic valve 3, and plunger 28 locks the push button against operation.

The invention provides a one hundred per cent safety shut-off for a gas pilot control that adds to the safe operation of athermostatically operated domestic water heater or other heater with which it may be employed.

-`Various embodiments of the invention may be employed within the scope of the accompanying claims.

I claim:

l. In a safety control for gas heaters having a main burner, a pilot burner, and a safety shut off valve operated thermostatically in response to a llame from said pilot burner to open position for supplying gas to the pilot burner and the main burner, the combination of a manually operable pilot valve to supply gas to the pilot burner when said safety shut off valve is closed, a main shut off valve having a handle to move the same between closed, "start" and open" positions to supply gas to said pilot valve when in start position, ,and a plunger connected by a cam to said handle at one end and extending into a groove in said pilot valve at the other end, said plunger being removed from said groove by said cam when the main shut valve is turned by said handle to "start position to provide for operation of said pilot valve and disposed in said groove when the main shut off valve is turned by said handle to closed and to open positions to prevent operation of said pilot valve.

2. In a safety control for gas heaters having a manually operable pilot valve to initially supply gas to a pilot burner, anda manually operable main shut off valve, a handle on said shut off valve to turn the same to closed", start and "open" positions, a plunger extending between said handle and the pilot valve, a head on the outer end of said plunger, a cam groove in the underside of said handle disposed to confine said plunger head and to control the longitudinal position of said plunger at all times in correlation to the rotary position of said handle, and means to interlock the plunger and said pilot valve to prevent movement of the latter from closed to open position when said main valve is turned to closed or open position by said handle and to release said interlock when said main valve is turned to start position.

3. In a safety control for gas heaters having a manually operable pilot valve to initially supply gas to a pilot burner, and a main shut off valve, a handle on said main shut off valve to turn the same to closed", start and open positions, a plunger secured at one end to a cam on said handle and disposed for longitudinal movement to engage and disengage said pilot valve` said plunger being pulled outwardly by said cam when the handle is turned to start" position, to disengage the plunger from said pilot valve and permit manual operation` of the latter, andmeans biasing said plunger inwardly when 'the handle is turned to "closed" or open position to engage said pilot valve and lock the same against manual operation thereof.

4. In a safety control for gas heaters having a. main shut off valveand a manually operable pilot valve, a. detent plunger adapted to engage vsaid pilot valve and lock the same in closed position against operation, a spring normally pressing said plunger into locking engagement with the pilot valve. a handle for operating said main shut off valve, and a cani operated by the movement of said handle and engaging said plunger to lift the same out of locking position and A against said spring to release the pilot valve for operation when saidmain shut off valve is in a predetermined position for lighting the pilot,

l ERNST R. KOPPEL'J REFERENCES' CITED The following references are of record in the nie of this patent:

UNITED STATES PATENTS 2,361,944 Jackson et al. Nov. 7, 1944

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