US2555433A - Automatic safety shutqff system for - Google Patents

Description

June 5, 1951 F. M. WOLFE AUTOMATIC SAFETY SHUTOFF SYSTEM FOR GAS BURNERS COMPRISING TWO LATCHING MEANS 2 Sheets-Sheet 1 Filed March 4, 1947 //VVE/v 70R. flora M. WOLF/E June 5, 1951 BURNERS COMPRISING TWO LATCHING MEANS Filed March 4, 1947 9 24 zany/a 25 2 j: Z 6/ a 28 52 ill q m 0 a 7 -g0 I 1 6 i n 50 53 8 I 1 49 ,7

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A 7' TORNE V.

Patented June 5, 1951 UNITED AUTOMATIC SAFETY SHUTOFF SYSTEM FOR GAS BURNERS COMPRISING TWO LATCH- ING MEANS Floyd M. Wolfe, Denver, 0010.

Application March 4, 1947, SerialNo. 732,185

11 Claims. I

This invention relates to. a gas burner safety control and has. for its principal object the provision of means. for controlling the gas supply to a gas burner in consequence of the operation of the pilot light employed for ignitin the burner so that gas cannot flow to either the burner or the pilot burner unless the latter is. properly ignited.

Accidents often occur from the use of gas burners due to the fact that the pilot burner will become extinguished from down drafts or from other causes. The thermostat controlling the main valve will then turn the gas into the main burner, filling the fire-box with raw explosive gas.

An object of this invention is to provide a. device which will automatically close the gas supply line to the main burner whenever the pilot burner becomes extinguished, and to provide means which. will prevent the main gas supply line from being opened until the pilot burner has.

been. properly ignited.

Devices have been arranged to electrically shutoff the gas supply to a main burner in case the pilot burner is extinguished. These devices, however, do. not operate to shut off the supply of gas to the pilot burner, and as a result the raw pilot burner gas will often fill the fire-box to an explosive extent.

Another object of this invention is to provide means. which, when the pilot burner is accidentally extinguished will not only shut. off the merals refer to like parts in all views of the.

drawing and throughout the description.

In the drawing:

Fig. 1 is a plan view of the improved burner control in the normal operating position;

Fig. 2 is alongitudinal section thereof taken on the line 2-2, Fig. 1;

Fig. 3 is avertical cross section taken on. the line 33 Fig. 2;

Fig; 4 is a horizontal cross section taken on the line 4--4, Fig. 5;"

Fig. 5 is a vertical section taken on the line 5-5, Fig. 2, with the control shown in the starting or igniting position;

Fig; 6 is an enlarged, vertical, detail section taken on the line 66, Fig. 4;

Fig. 7 is a similarly enlarged, vertical detail section taken on the line 1-1, Fig. 4; and

Fig. 8 is a similarly enlarged, horizontal detail section through the pilot burner, taken on the line 8-8, Fig. 3.

The invention is designed to control the gas supply line to any conventional gas burner bymeans of a control valve, designated in its entirety by the numeral to. The control valve contains an intake chamber H and an outlet chamber l2 provided with the usual threaded pipe receiving sockets 13. The fiow of gas from the chamber II to the chamber 12 is controlled by means of a disc valve l4 positioned to contact a valve seat l5.

The disc valve [4 is provided with a valve stem l6 which extends upwardly through a suitable packing gland I! and through a control box iii; The valve stem I6 is provided, within the. box ill, with an upper flange 19 and a lower flange 2B. A compression spring 2! acts against the upper flange H] to urge the. valve disc: [4 towards its seat I 5.

The valve [4 is supported in the open position of Fig; 2 by means of a swinging latch 23 carried bya locking lever 22 mounted on latch pin 25. The latch 23 is constantly urged toward the up 'per flange is by a suitable torsion spring 24. The spring 24 engages the lever 22 at its: one extremity and engages a fulcrum pin 69 at its other extremity so that the reaction of the spring is carried to the lever 22. The lower extremity of the locking lever 22 is provided with a pointed. tooth 26- which engages a toothed rack 2'! on the upper surface of a. horizontally positionedcontrol bar 28.

The control bar 28 is slidably mounted so that it may be moved back and forth. through the medium of a connecting rod 29 which extends to a thermostatically expansible bellows 30; The bellows 30 is positioned in a protecting. frame 3| positioned adjacent the fire box or burner of the heat plant. A supporting tube 32 extends from the frame 3|. to the control box |8.about the connecting rod 29.

The bellows 30 terminates in an expansion chamber 33 positioned adjacent the pilot. flame from a pilot burner tip 34 so that the head thereof will expand the bellows 39 so as to forcev the control bar 28 to the left in Fig. 2. This moveallows the valve M to drop under the influence of the spring 2| so as to shut off the supply of gas to the outlet chamber l2 and to the main burner.

The lug shaft 59 also carries a second lug 6| positioned at right angles to the first lug 58. When the valve i4 opens, the lug shaft will be rotated to bring this second lug in the path of a second dog 61, mounted on the cam 53 to lock the valve 43 in the normal position of Fig.

Let us assume that the mechanism is in the position of Fig. 2 and that gas is flowing from the intake chamber I! to the outlet chamber |2 and from thence to the burner and through the passage 42, valve 43, and tube 39 to the pilotlight.

' The mechanism remains in this position as long The control rod 28 is provided on its underside with a second tooth-ed rack which acts against a pointed extremity 36 on a second locking lever 3! to swing the latter to and from the lower disc 20. The second lever 31 is provided with a latch member 38 which, when the control rod 28 moves to the right, swings above the lower flange 20, as shown in broken line in Fig. 2, to prevent the valve M from being opened. When the control rod 28 moves to the left under the influence of the expanding bellows 39 the second lockinglever 31 will be swung to the solid line position of Fig. 2 so as to release the flange 20 and allow the valve I4 to be'opened, as will be later described.

The gas is fed to the pilot burner through a gas, tube 39 extending to a pilot burner valve housing 49 formed, or secured, on the side of the control valve l0. Two passages 4| and 42 communicatebetween the pilot burner housing 40 andthe intake chamber I and the outlet chamber I2, respectively. The passages 4| and 42 are controlled by means of a two-way plug valve 43 maintained in a tapered valve seat by means of a valve spring 44. i

The plug valve 43 is provided with two ports 45 and 46 which open the passages 4| and 42, respectively, to the hollow interior of the valve 43. The ports 45 and 45 are positioned at right angles to each other. The gas from either passage discharges from the hollow interior of the valve 43 through a discharge port 41 to an annular receiving chamber 48 communicating with the gas tube 39.

The pilot burner valve 43 may be rotated from a Valve shaft 49 which extends through a cam 'box 59 and terminates in a control handle 5|.

The control handle 5| is constantly urged toward the position of Figs. 1 and 3 by means of a return spring 52. To open the port 46 to the passage 4| it is necessary to manually rotate the handle 5| against the action of the spring 52 to the position of Fig. 5.

The valve shaft 49 is provided with a cam 53 against the cam surface of which a cam follower 54 bears. The cam follower is pivoted on a cam pin 55 and is provided with a bifurcated spring arm 56 which extends beneath the lower flange 20. When the lever 5| is swung from the position of Fig. 1 to the position of Fig. 5, the cam 53 will force the follower 54 downwardly, putting tension in the spring arm 56 to urge the valve stem IE to open the Valve [4. The lever 5| is temporarily held in the position of Fig. 5 by means of a swinging dog 51, which engages a lug as the pilot light is lighted.

Now let us'assume that the pilot burner becomes extinguished. This causes the bellows 3D to contract to pull the latch member 22 from beneath-the upper flange l9 to the spring 2| to V the'burner, for the valve I4 is locked closed by 58 carried on a rotatable lug shaft 59 which exmeans of the locking lever 31. The lever 5| remains in the operating position of Fig. l.

To start the burner, the lever 5| is turned from the position of Fig. l to the starting or igniting position of Fig. 5. the intake'chamber through the passage 4|, and the tube 39 to the pilot burner. is automatically locked in this position by the dog 5'! and lug 58. The pilot flame is now ignited.

As soon as the pilot flame has heated the expansion chamber 35 sufficiently, the bellows will expand to the left swinging the locking lever 31 away from the flange 20 and allowing the spring arm 56 to snap the valve |4 open and allowing theflange I9 to move past the latch member 22 to lock-the valve open. In moving to the open posie tion'the flange 25 will, through the medium of the arm 69, rotate the shaft 59 to swing the lug 58 from the path of the dog 51. This allows the spring 52 to return the pilot burnervalve 43 to the position of Fig. 3 so that gas will flow through the passage 42 and port 46 from the outlet chamber l2 to the pilot burner. When the handle 5| reaches the position of Figs. 1 and 3 the second dog '51 will engage the second lug 6| to lock the valve 43 open and to prevent the pilot burner gas from being shut off. 7

Thus it can be seen that gas cannot flow to the burner unless the pilot burner has been lighted, and that no gas can flow to the pilot burner until it is reignited.

There might be emergencies arise in which the pilot burner would become extinguished before it had heated the expansion bellows to a point to operate the valve, and since the pilot burner valve is locked in the open position of Fig. 3 by the latch member 6|, it would be impossible for the operator to shut off the burner.

For such cases, a sliding sleeve62 may be provided on the shaft 59 for carrying the lugs 58 and 6|. This sleeve is keyed to the shaft 59 by means of a key '63 riding in an elongated slot 64 in the sleeve 62. Outward movement of the sleeve 62 is prevented by means of a tubular cap 65 which extends to the exterior of the ,cam box 59. The cap is normally prevented from moving outward by means of a boss 66 which bears against the side of the box 59. When the cap 65 is turned to one position the boss 66 may exit through a slot 61 to allow the cap to move outward so that the lug 58 may move out of the way of the dog 51 so that the spring 52 may This allows gas to flow from The handle gas to the extinguished pilot return the pilot burner valve to the inoperative position.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is:

1, In combination, a pilot burner; a thermoexpansible unit placed to receive heat from said pilot burner; a control bar longitudinally movable by said thermo-expansible unit; a main gas valve; a pilot gas valve; a locking latch for holding said main valve open; a second locking latch for holding said main valve closed; and means on said control bar for actuating the second latch to the holding position and releasing the first latch when said thermoeexpansible unit contracts and for actuating the first latch to the holding position and releasing the second locking latch when said thermo-expansible unit expands.

2. A control for gas burners comprising: a pilot burner; a thermo-expansible unit placed to receive heat from said pilot burner; a control bar longitudinally movable by said thermoexpansible unit; a main gas valve; spring means urging said main valve closed; a pilot burner valve; a locking latch for holding said main valve open; engaging means operable from said control bar for actuating said latch to the holding position; releasing means operable by said control bar for releasing said latch from said main valve so that said spring means will close the latter when the pilot burner is extinguished; and means operable from said pilot burner valve for exerting an opening action on said main gas valve when said pilot burner is operated to turn gas to said pilot burner.

3. In a device of the class described, a main valve body having an intake chamber and a discharge chamber; a valve disc controlling the flow from said intake chamber to said discharge chamber; resilient means urging said valve disc to the closed position; a valve stem extending from said disc; a control bar extending laterally across said valve stem; a pilot burner; a thermoexpansible member positioned adjacent said pilot burner; a connecting rod connected between said therrno-expansible member and said control bar for moving the latter transversally of said valve stem in consequence of the movements of the former; a projection on said valve stem; a swinging latch adapted to engage said projection to hold said valve disc open; and means on said control bar positioned to engage said latch to release the latter when said pilot burner is extinguished to allow said resilient means to close said valve.

4:. In a device of the class described, a main valve body having an intake chamber and a discharge chamber; a valve disc controlling the flow from said intake chamber to said discharge chamber; resilient means urging said valve disc to the closed position; a valve stem extending from said valve disc; a control bar extending transversally across said valve stem intermediate the extremities thereof; a pilot burner; a thermoexpansible member positioned adjacent said pilot burner; a connecting rod connected between said thermo-expansible member and said control bar for moving the latter transversally of said valve stem in consequence of the movements of the former; a projection on said valve stem at one side of said control bar; a swinging latch adapted to engage said projection to hold said valve disc open; means on said control bar for engaging said latch to release the latter from said projection when said pilot burner is extinguished; a second projection on said valve stem on the other side of said control bar; a second swinging latch for engaging said second projection to hold said valve disc closed; and means operable from said control bar for releasing second said latch from said second projection when said pilot burner is ignited.

5. In a device of the class described, a main valve body having an intake chamber and a discharge chamber; a valve disc controlling the flow between said chambers; a pilot burner; means for opening and closing said valve disc in response to the heat from said pilot burner; a pilot valve housing positioned adjacent said main valve'body; a hollow ported pilot burner valve in said latter housing controlling the flow to said pilot burner; a first passage in said body and housing extending from said intake chamber to said pilot burner valve; a second passage in said body and housing extending from said discharge chamber to said pilot burner valve; a third passage in said pilot valve housing; means for rotating said pilot burner valve when said main valve is closed so as to place the first passage in communication with the third passage so as to connect the pilot burner with the intake chamher; and spring means for returning said pilot burner valve toits former position to place the second passage in communication with the third, passage so as to connect the pilot burner with said discharge chamber when the valve disc is open.

6. A control for gas burners comprising: a D1101; burner; a thermo-expansible unit placed to receive heat from aid pilot burner; a control bar longitudinally movable by said thermo-expansible unit; a main burner valve having an intake and a discharge side; spring means urging said main valve closed; a locking latch for holding said main valve open; engaging means operable by said control bar for actuating said latch to the holding position when said pilot burner is ignited; releasing means operable by said control bar for releasing said latch to allow said main valve to close when the pilot burner is extinguished; a pilot burner valve, there being a first gas passage communicating between the intake side of said main valve and said pilot burner valve and a second gas passage communicating between the discharge side of said main valve and said pilot burner valve and a third gas passage communicating between said pilot burner and said pilot burner valve; and a port in said pilot burner valve positioned to register with each of said passages, said ports being interconnected in said pilot burner valve so that rotation of the pilot burner valve will place either the first or second passage in communication with said third passage and said pilot burner.

'7. A control for gas burners comprising: a pilot burner; a thermo-expansible unit placed to receive heat from said pilot burner; a control bar longitudinally movable by said thermo-expansible unit; a main burner valve having an intake and a discharge side; spring means urging said main valve closed; a locking latch for holding said main valve open; engaging means operable by said control bar for actuating said latch to the holding position when said pilot burner is ignited; releasing means operable by said control 7'. bar forireleasing said latch to allow said main valve to close when the pilot burner is extinguished; a pilot burner valve, there being a first gas passage communicating between the intake side of said main valve and said pilot burner valveand a second gas passage communicating between the discharge side of said main valve and aid pilot burner valve and a third gas passage communicating between said pilot burner and said pilot burner valve; a port in said pilot burner valve positioned to register with each of said passages, said ports being interconnectedin said pilot burner valve so that rotation of the pilot burner valve will place either the first or second passage in communication with said third passage and said pilot burner; a manual handle for rotating said pilot valve to place said first passage in communication with said pilot burner; and automatic means operable by said main gas valve and acting to return said pilot valve into communication with said second passage when said main valve is opened.

8. A control for gas burners comprising: a pilot burner; a thermo-expansible unit placed to receive heat from said pilot burner; a control bar longitudinally movable by said thermo-expansible unit; a main burner valve having an intake and a discharge side; spring means urging said main valve closed; a locking latch for holding said main valve open; engaging means operable by said control bar for actuating said latch to the holding position when said pilot burner is ignited; releasing means operable by said control bar for releasing said latch to allow said main valve to close when the pilot burner is extinguished; a pilot burner valve, there being a, first gas passage communicating between the intake side of said main valve and said pilot burner valve and a second gas passage communicating between the discharge side of said main valve and said pilot burner valve and a third gas passage communicating between said pilot burner and said pilot burner valve; a port in said pilot burner valve positioned to register with each of said passages, said ports being interconnected in said pilot burner valve so that rotation of the pilot burner Valve will place either the first or second passage in communication with said third passage and said pilot burner; a manual handle for rotating said pilot valve to place said first passage in communication with said pilot burner; means for locking said pilot valve in communication with said first passage; a spring urging said pilot valve into communication with said second passage; and releasing means operable from the opening action of said main valve for releasing said locking means so that said latter spring may return said pilot valve into communication with said second passage when said main valve is opened.

9. A control for gas burners comprising: a pilot burner; a thermo-expansible unit placed to receive heat from said pilot burner; a control bar longitudinally movable by said thermo-expansible unit; a main burner valve having an intake and a discharge side; spring means urging said main valve closed; a locking latch for holding said main valve open; engaging means operable by said control bar for actuating said latch to the holding position when said pilot burner is ignited; releasing means operable by said control bar for releasing said latch to allow said main valve to close when the pilot burner is extinguished; a pilot burner valve, there being a first gas passage communicating between the in- 8; take side of said main valve. and said pilot burner valve and a second gas passage communicating between the discharge side of said main valve and said pilot burner valve and a third gas passage communicating between said pilot burner andsaid pilot burner valve; a port in said pilot burnervalve positioned to register with each of said passages, said ports being interconnected in said pilot burner valve so that rotation of the pilot burner valve will place either the first or second passage in communication with said third passage and said pilot burner; a manual handle for rotating said pilot valve to place said first passage in communication with said pilot burner; automatic means operable by said main gas valve andiacting to return said pilot valve into communication with said second passage when said main valve is opened; locking means automatically engaging said pilot valve to lock the latter in communication with said second passage when said main valve is opened; and a releasing member extendin from said main valve to said pilot valve and arranged to release said locking means when said main valve closes.

10. A control for gas burners comprising: a pilot burner; a thermo-expansible unit placed to receive heat from said pilot burner; a control bar longitudinally movable by said thermo-expansible unit; a main burner valve having an intake and a discharge side; spring means urging said main valve closed; a locking latch for holding said main valve open; engaging means operable by said control bar for actuating said latch to the holding position when said pilot burner is ignited; releasing means operable by said control bar for releasing said latch to allow said main valve to close when the pilot burner is extinguished; a pilot burner valve, there being a first gas passage communicating between the intake side of said main valve and said pilot burner valve and a second gas passage communicating between the discharge side of said main valve and said pilot burner valve and a third gas passage communicating between said pilot burner and said pilot burner valve; a port in said pilot burner valve positioned to register with each of said passages, said ports being interconnected in said pilot burner valve so that rotation of the pilot burner valve will place either the first or second passage in communication with said third passage and said pilot burner; a manual handle for rotating said pilot valve to place said first passage in communication with said pilot burner; automatic means operable by said main gas valve and acting to return said pilot valve into communication with said second passage when said.

main valve is opened; a cam mounted on said pilot valve; a spring arm pivoted intermediate its extremities and contacting said cam at its one extremity and said main valve at its other extremity, said cam' being contoured to cause said spring arm to exert an opening action on said main valve when said pilot valve is rotated manually by said manual handle. a

11. A control for gas burners comprising: a pilot burner; a thermo-expansible unit placed to receive heat from said pilot burner; a control bar longitudinally movable by said thermo-expansible unit; a main burner valve having an intake and a discharge side; spring means urging 7 said main valve closed; a locking latch for holdbar for releasing said latch to allow said main valve to close when the pilot burner is extinguished; a pilot burner valve, there being a first gas passage communicating between the intake side of said main valve and said pilot burner valve and a second gas passage communicating between the discharge side of said main valve and said pilot burner valve and a third gas passage communicating between said pilot burner and said pilot burner valve; a port in said pilot burner valve positioned to register with each of said passages, said ports being interconnected in said pilot burner valve so that rotation of the pilot burner valve will place either the first or second passage in communication with said third passage and said pilot burner; a manual handle for rotating said pilot valve to place said first passage in communication with said pilot burner; automatic means operable by said main gas valve and acting to return said pilot valve into communication with said second passage when said main valve is opened; and a manually actuated release device for releasing said latter locking means when desired.

FLOYD M. WOLFE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,325,896 Long Dec. 23, 1910 1,607,343 Davenport Nov. 16, 1926 1,773,817 Leach Aug. 26, 1930 1,823,122 Partlow Sept. 15, 1931 1,952,332 Partlow Mar. 27, 1934 1,975,142 Fonesca Oct. 2, 1934 2,041,559 Marks May 19, 1936 2,203,691 Mantz June 11, 1940 2,288,208 Rabinowicz June 30, 1942

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