US2341967A - Safety control for gaseous fuel burners - Google Patents

Description

V. WEBER SAFETY CONTROL FOR GASEOUS FUEL BURNERS Feb. 15, 1944.

Fil ed June 25, 1941 VlgToR WEBER ATTORNEY.

Patente eh, i, 19

stares PATEN 2,341,967 SAFETY CONTROL FGR GASEOUS FUEL BURNERS Victor Weber, Greensburg,

ertshaw Thermostat Company,

Pa, assignor to Rob Youngwood,

a corporation of Pennsylv Application June 25, 1941, Serial No. 399,364

An object of the invention is to cause complete and automatic shut-01f of all fuel to both the main and pilot burners when the pilot burner becomes extinguished.

Another object of the invention is to permit fuel to flow to the pilot burner during starting operation while preventing any flow to the main burner.

Another object of the invention is to maintain the'pilot burner in continuous operation regardless of whether or not fuel is flowing to the main burner.

Another object positive snap-acting means for accomplishing the shut-oil.

Another object of the invention is to arrange the control in compact form as a unitary constructicn which is adapted for manufacture at low cost and which space when installed in the gas appliance.

Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawing, wherein:

Fig. 1 is a plan View partly in section of the safety control;

Fig. 2 is a longitudinal sectional view through V the control;

Fig. 3 is a section taken on the line 3-3 of Fig. 1 looking in the direction indicated by the arrows; and I i Fig. 4 is a section taken on the line i-i of Fig. 2 looking in the direction indicated by the arrows.

Referring more particularly to the drawing, the control device comprises a housin ill having an inlet 12 in one side thereof and an outlet it substantially perpendicular to the inlet. The inlet i2 and outlet l4 communicatewith a charm her It extending partly through the housing it! and terminating in a flat bottom portion it. The inlet l2 and outlet I 4 intersect the chamber 48 intermediate the ends thereof and provide passageways for gaseous fuel to flow therethrough to a main burner connected by any suitable means to the outlet it. The upper portion of the chamber i6 is threaded for the reception of a cap 2E3 which serves toclose the open end of the chamber l5.

a valve seat member is positioned within of the invention is to utilize.

5 Claims. (Ci. 158-1l17.1)

the chamber It. The valve seat membe is gem erally cylindrical in form, having an upper threaded portion engaging the threaded portion of the *hamber I6 below the cap 20, and an unthreaded portion closely fitting within the lower portion of the chamber IS with its bottom face seated. upon the bottom portion l8 of the chamber.

A recess 24 is provided in the bottom face of the valve seat 22 and an annular knife-edge portion 26 projects inwardly thereof to form a seat for a snap disc 28. The snap disc may be of any suitable form and, in this instance, is concavely curved when free. The disc is supported in the recess 24 by a thrust element 30 provided with an annular knife-edge portion 32 similar to the porti0!1 26. In this embodiment the knife-edge 28' will occupy the minimum of is smaller in diameter than the knife-edge 32 and is thus positioned inwardly thereof with respect to the disc 28 to provide the necessary leverage for operation. Both the disc 28 and thrust element 30 have their marginal edges spaced from the walls of the recess 24 providing an annular passage therearound.

The thrust member 30 is loosely supported within the recess 24 and receives an axial thrust from the rod portion 33 of a thermally responsive element 34. The thermally responsive element may be-of the rod-and-tube type, and is supported from the housing ill by the tube portion which threadedly engages a projection 38 carried by the housing it.

The valve seat member 22 is provided with an annular passage 38 extending from the upper end thereof and terminating adjacent the recess it. A plurality of apertures it extend transversely through the wall of the valve seat member 22 intermediate itsends and afford communication between the annular passage 38 and the outlet it. A. second annular passage 42 is formed in the valve seat member 22 within the margin of the other annular passage 38 and substantially concentric therewith. lhe annular passage 42, however, extends completely through the valve seat member 22 and communicates with the recess it being interrupted only by a pair of oppositely disposed webs t3 extending across the lower portion of passage i2 from one wall to the other. Both the outer wall around the annular passage E33 and the inner wall it remaining between the two passages are provided. with sharp-edged rims. This construction forms a double valve seat comprising an outer portion it and an inner portion 38.

A valve member at is supported in the chamber valve of any suitable form.

housing Ill. The packing chamber I8 for coaction with the double valve seat formed on the valve seat member 22. The supporting and operating means for the valve member 50 comprises a valve stem 52 slidably engaging an axial opening in the valve seat member 22 and carrying a threaded projection 54. The projection 54 engages the snap disc 28 on the side opposite the thrust element 30 and is adjustable with respect thereto due to its threaded engagement with the valve stem. A coil spring 58 extends between the valve member 50 and the underside of the cap 20 and assists the valve member 50 in returning to its seat when the snap disc 28 permits.

Passage of fluid from the chamber I8 to the outlet It is controlled by a manually operated In this instance, the valve comprises a tapered plug cock 58 engaging with a tapered seat 80 formed in the housing i and having a passage 62 therethrough movable into and out of alignment with the outlet upon rotation of the cock 58 in its seat. The cock 58 is provided with a handle 64 carried on a stem 88 projecting from the cock 58 beyond the housing Ill.

The device of this invention not only provides control of the fluid passing through the outlet I4 and thence to the main burner, but also provides control or the passage of fluid to a pilot burner. To this end, a passage 88 is formed in the housing communicating with the chamber I8 above 30 the valve seat member 22. The passage 88 leads to a tapered opening F0 in the housing I8 forming a seat for a pilot shut-off cock I2. The pilot shut-oil cock I2 is in the form of a tapered plug having a head projecting from the housing and provided with a handle I4 for manual rotation of the cock in its seat. The cock is retained in its seat by means of a spring plate I6 secured in a recess formed in the cock between the head and the tapered portion thereof and fastened to the housing I0 by a screw 11.

The cock I2 is further provided with mangular passage I8, one end of which is movable into registry with the passage 68 when the cock is rotated in its seat, and the other end of which opens at the smaller end of the tapered portion. An angular passage 80 is formed in the housing I0 and communicates at one end with the passage I8 and at the other end with a pilot control valve chamber 82 also formed in the housing I0.

iAdjacent the valve chamber 82 is an enlarged opening 84 extending to the exterior of the housing I0 at the lower end thereof and provided with a threaded portion for the reception of a closure cap 88. The shoulder formed by the portion of the bore 10 obtaining access to larged opening 84 below the valve seat 88 to a bore I08 within which a pilot adjusting member H8 is rotatably mounted. The upper end of the pilot adjusting member IIO projects into an enlarged I08 at the exterior of the housing I0 and is provided with a slot H2 by means oi which the member may be rotated in the bore. The enlargement may be threaded for the reception of a closure cap II4 which is removable for the pilot adjusting member IIO when required. An elongated slot H8 is formed in one side or the pilot adjusting member IIO adjacent the passage I08 and communieating with an opening H8 formed axially in the lower portion of the pilot adjusting member H0.

The opening 8 communicates with a lateral passage I in the housing I0 leading to a threaded connection I22 tor a pilot burner I24. The pilot burner extends from the housing I0 20 substantially parallel with, and adjacent to, the

thermally responsive ment will be heated by the pilot flame.

In order to provide for passage of fluid to the pilot burner I24 when the main valve 50 is open and the pilot control valve 90 is closed, a by-pass is provided in this construction. This by-pass takes the form of an angular passage I28 extending from the bottom portion I8 of the chamber I8 and communicating with the enlarged opening 84 below the pilot control valve member 80. To afford communication between the passage I28 and the main valve chamber I6 around the snap disc 28, the knife-edge seat 25 is provided with a plurality of slots I28 through which the fluid may pass.

of the device is asiollows: In to which the control is 58 controlling the outlet The operation starting the appliance attached the gas cock I4 should be in closed position. Under such conditions and assuming that the thermally responpass through the by-pass to the pilot burner I24 also be in closed position at sive element is not operating, the valve 50 will also be closed due to the normal or concave position of the snap disc 28. The valve 50 being in closed position no fluid from the chamber IScan and the pilot control valve 80 being normally closed also prevents fluid from passing to this pilot burner. Additional safety is provided by the provision of the pilot shut-oft cock 12 which may this time.

The appliance is started by firstmanually depressing the pilot control valve 90 by means of the push-button I04 permitting fluid to pass from the valve chamber I8 by way of passages 58, 80,

and I06 to the pilot adjustment member IIO.

junction of the enlarged openin 84 and the valve chamber 82 forms a seat 88 for a pilot control valve member 90. The valve member 80 is provided with a stem 92 extending through the valve chamber 82 and upwardly through a packing chamber 94 formed in the upper portion of the 9B is provided with a-packing 9B which is compressed into sealing engagement with the stem 92 by means of a spring 98 engaging with the underside of a closure cap I00 threaded into the outer end of the packing chamber 94. A second spring I02 extends between the valve member 90 and the bottom closure cap 86 and serves to maintain the valve member 90 in engagement with its seat 88. The projecting end of the valve stem 92 is provided with a button I08 by means of which the valve member 00 may be moved manually from its seat against the pressure of the spring I02.

A passage I08 extends laterally from the en- This member is normally left in adjusted position and the fluid may pass through the slot I I8 therein and out of the opening 8 to enter the passage I20 which communicates with the pilot burner I24. The pilot burner m then lighted and causes operation of the thermally responsive element 34 in the usual manner to create a thrust. against the thrust plate 30 moving it away from bottom portion I8 and operating the snap disc 28 to the convex position as shown in the drawing.

By means of the projection 54 described, the movement of the snap disc 28 causes movement of the valve member 50 from its double seat exposing both annular passages 38 and 42. The

fluid in the valve chamber I5 may then now by way of annular passage 38 and apertures 40 to the outlet I4. If not previously opened, the main gas cock 58 may then be rotated to open position and the fluid will pass to the main burner which may then be lighted.

element 34 so that this ele- Such closing of the pilot control valve 90 will of fuel to the pilot burner valve member cooperating with said seat for controlling the passage of fuel from the inlet to the not shut 011 all fiow 3 municating with both the inlet and outlet openins and the other annular passages one within the other and substantially concentric, the inner and outer walls only, a by-pass communicating with the last said passage for diverting fluid from the outlet opening, a valve member coacting with auxiliary valve, iliary valve to a pilot burner, actuating means for said auxiliary valve for controlling the flow vrc'ron EBE

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