US2728386A - Gas regulating device - Google Patents

Description

Dec. 27, 1955 J. H. THORNBERY GAS REGULATING DEVICE Filed June 29, 1951 3&1.

2 Sheets-Sheet l ZQZ.

| l I I l Jahn H Tharnbgzy #Wmv Dec, 27, 1955 J. H. THORNBERY 2,728,386

GAS REGULATING DEVICE Filed June 29, 1951 2 Sheets-Sheet 2 www# ` Figure 1 along the line GAS REGULATIN G DEVICE John H. Thornbery, Whiteiish Bay, Wis., assignor tolMilwaukee Gas Specialty Company, Milwaukee, Wis., a corporation of Wisconsin Application June 29, 1951, Serial No. 234,310 16 Claims. (Cl. 158-131) This invention relates to gas regulating devices and has more particular reference to thermoelectric control valves for regulating the supply of gas to the main burner of a gas appliance as well as to the pilot burner therefor.

ln a preferred form, it is an objective of this invention to combine with a more or less conventional thermoelectric gas shut off valve a novel control means for not only regulating the flow of gas to the pilot burner of an appliance but for filtering the gas supplied to the pilot burner as well. In this preferred form the control means may comprise a hollow knob mounted on the exterior of the valve and containing a filter in its interior, with passages formed in the valve body and the knob to divert gas from the main passage of the valve out of the body of the valve and into the control knob, through the filter therein, and thence to the pilot port on the valve body so as to assure the delivery of clean gas to the pilot burner.

A further purpose of this invention is to mount the hollow control knob on the exterior of the thermoelectric shut off valve for rotation relative to the valve body to accomplish metering of the flow of gas to the pilot burner by the partial misalignment which such rotation of the knob may effect between one end of its passageway and the end of the adjacent passage in the valve body communicating therewith.

Still another purpose of this invention is to maintain the pressure of gas supplied to the pilot burner as uniform as possible; and this objective is accomplished by embodying a pressure responsive valve element in the control knob passageway to increasingly restrict the same in direct proportion to any increase in the pressure of the gas introduced into the interior of the knob.

Y A further purpose of the invention is to so construct the control element that the lter therein may-be made readily accessible for inspection or replacement.

With the above and other objects in view, which will appear as the description proceeds, this invention resides in the novel construction and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereinafter disclosed invention may be made as come within the scope or the claims.

The accompanying drawings illustrate two complete examples of the physical embodiment of the invention constructed in accordance with the best modes so far devised for the practical application of the principles thereof, and in which:

Figure l is a side elevational view showing the application of this invention to a more or less conventional automatic gas shut on? valve of the thermoelectric type;

Figure 2 is a view similar to Figure 1 but with parts of the automatic shut ol in section to illustrate the interior constructionthereof;

Figure 3 is an enlarged sectional view taken through vto valve broken away and shown I 2,728,386 Patented Dec. 27, 1955 Figure 4 is an enlarged elevational view of the control element` per se, with portions thereof broken away to illustrate the disposition of the filter cartridge in the element; l o

Figure 5 is a perspective view of the control element and the stop plate therefor, the latter being shown separated from the control element and in the position it occupies upon the body of the shut off Valve; and

Figure 6 is a sectional view similar to Figure 3 but illustrating a modified embodiment of the invention.

Referring now more particularly to the accompanying drawings in which like numerals designate like parts throughout the several views the numeral 5 generally designates the control element of this invention. As shown best in Figure 1 the control element is preferably used with an automatic gas shut oi valve 6 of the thermoelectric type and which is commonly employed to supply gas to the main burner (not shown) of a gas furnace or other appliance only as long as the pilot burner 7 for the main burner remains lit. In the event of failure of the pilot llame the electromagnetic main valve 8 closes to not only shut off the supply of gas to the main burner but to also shut off the flow of gas to the pilot burner.

The manner in which this is known, and it will suice to note that the main valve 8 is heldopen, permitting gas to flow through the main passage 9 in the valve body l0, as long as its winding 11 is energized; and that the energizing E. M. F. for the winding is derived from a thermocouple 12 having its hot junction 13 disposed in position to be impinged by the pilot llame F. The valve 8, of course, is mounted on a stem which serves as a plunger or armature associated with the winding 11; the valve 8 being urged closed by a spring 14 encircling the valve stem and which is of such strength that its expansive force is overcome by the attractive force of the winding in the valve open position, whenever the winding is energized. It will also be noted that the valve v8 engages a seat 15 in the main passage' 9 of the valve, the seat 15 facing the inlet end 16 of the passage so that the pressure of gas in the supply line aids the compression spring 14 in holding the valve closed in the event of pilot failure.

The pilot burner 7 is connected with a pilot port 18 on the valve vbody by means of a duct 19, and as will appear hereinafter, the pilot port 18 though supplied with gas from the main passage 9 of the thermoelectric valve does accomplished is well 4not'communicatedirectly `with the main passage but does so indirectly through the control element S of this invention.

The control element'comprses a cup-shaped housing having a substantially cylindrical side wall 21 and a bottom 22 providing one end'wall of the element; and the open side of the cup has a closure or cover 23 providing an opposite end wall. The cover 23, however, is detachably secured in place by a plurality of screws 24 passing through the cover and threading into enlargements on the side wall of the cup. The cup is mounted with a preferably flat surface 25 on its end or bottom 22 seated flatwise against and in intimate contact with a mating surface 26 on a pad 27 on the exterior of the body 10 of the shut oif valve.

As seen best in Figure 3 the cup-shaped control element, with its detachable cover, provides a hollow knob which is rotatably mounted on the body 10 of the thermoelectric valve by means of a screw 28 having its shank passing loosely through a central hole 29 in the bottom 22 of the knob, from inside the same, with its extremity threaded into the valve body 10 substantially in radial alignment with'the valve seat 15 therein. A compression spring 30 contined between the underside of the head 3, 31 on the screw and a washer 32 resting upon a series of radial ribs 33 on the inside surface of the end wall 22 forcefully urges the cup against the valve body to hold the surfaces 25 and 26 on the cup and the pad in sealing engagement with one another. Since the hole 29 in the bottom wall 22 of the cup is coaxial with the cylindrical side wall thereof and is slightly larger than the diameter of the shank of the mounting screw, it will be apparent that the knob may be rotated back and forth about an axis coaxialwith the cylindrical side wall 21 of the cup.

An annular filter cartridge 34 is disposed inside the hollow interior of the knob, coaxially thereof, in a position encircling the head` 31 of the mounting screw. A gasket 36 of cork or similar material covers the entire outer end of the filter cartridge and is clamped betwen it and the cover 23; while the inner end of the cartridge is pressed firmly against an annular sealing washer 37 in the bottom of the cup upon tightening the screws 24 holding the cover in place on the knob.

Gas torbe supplied to the pilot burners? is diverted from the main passage 9 of the shut off valve through a passageway in the control knob leading through the filter therein, The inlet end of this knob passageway comprises a drilled hole 38 through the bottom wall 22 between the exterior of the filter cartridge and the cylindrical side wall 21 of the knob and opening to the fiat surface 25 on the knob a short distance to one side of the mounting screw for the knob. The other or outlet end 39 of the knob passageway opens to said surface on the knob at the opposite side of the mounting screw and opens to the interior of the knob inside the inner end of the filter cartridge.

Hence, gas entering the knob through the inlet end 38 of its passageway is constrained to ow radially inwardly through the filter, the iiltered gas discharging through the outlet end 39 of the knob passageway.

The gas diverted from the main passage 9 of the shut off valve for filtering prior to ow to the pilot burner is conducted into the inlet end of the knob passageway through an inlet branch passage 40 in the valve body communicating with the main passage 9 downstream from the valve seat V and opening to the at surface 26 on the body in register with the inlet end 38 of the knob passageway. The filtered gas leaving the knob through the outlet end 39 of its passageway is conducted to the pilot port on the valve body through an outlet branch passage 41 in the valve body having one end leading into the pilot port and its other end opening to the surface 26 on the valve body in register with the outlet end 39 of the knob passageway.

With the construction of the control knob as described, it will be noted, that in the position of rotation of the knob illustrated in Figure 3, for example, the ends of the knob passageway are in complete register with the adjacent ends of the inlet and outlet branch passages of the valve body so that gas liows substantially unrestrictedly through the filter in the control knob to the pilot burner. The rotatable connection between the knob and the valve body, however, makes it possible to close off the knob passageway entirely to shut off the ow of gas to the pilot burner, or to adjustably restrict the knob passageway any desired extent to achieve metering of the liow of gas to the pilot burner. Metering ofthe gas to reduce the ow to the pilot burnerl is accomplished by rotating the knob clockwise toward off to a position producing partial misalignment between the ends of the knob passageway and the adjacent ends of the branch passages in the valve body. However, since the inlet end 38 of the knob passageway preferably opens to the adjacent end of the inlet branch passage 40 of the body through an arcuately enlarged mouth 42, concentric to the knob axis, gas flows unrestrictedly into the knob and the meteringof the gas ow to the pilot burner is effected solely at the outlet end 39 of the knob passageway through which cleaned gas flows. This is an important advantage since if the inlet end of the knob passageway was not in full register with the adjacent end of the inlet branch passage of the valve body in a metering position of the control knob, dirt and other solid foreign matter in the incoming gas would very likely lodge in the restricted entrance to the knob passageway and build up objectionably to increasingly restrict or even interrupt the flow of gas to the pilot burner.

Further clockwise rotation of the control knob to the off position, of course, effects complete disalignment between the outlet end 39 of its passageway and the adjacent end of the outlet branch passage 41'of the valve body to shut off the supply of gas to the pilot burner.

It is desirable, of course, to limit the extent of back and forth rotation of the knob between positions either supplying a predetermined, metered amount of gasto the pilot burner, or shutting off the supply of gas to the pilot burner. For this purpose an adjustable stop plate 46 is provided. The stop plate comprises a relatively shallow cup-like part 47 having a fiat bottom wall 48 provided with a central aperture 49 to enable the plate to be rotatably received on a turned down hub on the end 22 of the control knob. The stop plate also has a substantially cylindrical side wall 50 encircling the adjacent inner end portion of the control knob, and a substantial portion of the side wall is cut away to provide circumferentially spaced opposing abutments 51 and 52 at the ends of the side wall. The plate also has a lateral extension 53V provided with an arcuate slot S4 therein concentric to the axis of rotation of the control knob; and a screw 55V passing through this slot and threaded into the adjacent side of the valve body is employed to releasably lock the stop plate to the body in any desired position of rotation relative to the body.

The abutment 51' a lug S7 on the exterior of the control knob to limit rotation of the knob in the on direction, and depending upon the angular adjustment of the stop plate determines the degree of alignment or misalignment be tween the outlet end 39 of the knob passageway and the adjacent end of the outlet branch passage 41 in the valve body. The abutment 52, of course, is engageable by the lug 57 during rotation ofthe control knobV in the off direction at a positionvsuch that the outlet end 39 of the knob passageway will be completely out of register with thel adjacent end of the outlet branchV passage 41 of the valve body.

Inspection and/orl replacement of the filter cartridge 34- is easily accomplishedupon the removal of the screws 24 holding the cover 23 in place upon the knob. After replacement of the ltercartridge the same screws 24 clamp the filter cartridge endwise between the imperforate gasket 36 at the outer end of the knob and the annular sealing ring 37 in the bottom of the knob cavity.

The-embodiment of thev invention illustrated in Figure G-is in most respects similar to that previously described with the exception that the control knob is substantially turned end for end. This brings its detachable end closure 23 against the surface 26 of the pad on the exterior ofthe valve body. A screw 59 passing freely through a central hole 60 in said end closure and threading into a hole in the valve body has a compression spring 61 confined between its head 62 and the bottom of a counterbore 63 in the endvclosure to hold the knob firmly in place onV the body. In this case, both the head 62 of the: screw and the spring 61 are disposed within the counterbore 63, and the spring likewise seats the knob against the valve body with a force preventing leakage of gasvat the-joint between-the end closure 23' and the valve body.

The inlet and outlet ends 38 and 39 respectively of the passageway inthecontrol knob are likewise formed in the end closure 23', with thev inlet- 38 leading to the space surrounding theexterior of the filter cartridge-34' as in the previous embodiment of' the invention so that on the stop plate is engageable by Y f gas entering the interior ofthev control knobflows radially inwardly through the filter -cartridge tothe spaceinside the same. The gas thus filtered, however, flows axially outwardly of the central space in the knob through a hole 65 in the bottom wall 22 of the cup-shaped knob and into a diaphragm chamber 66 defnedby the bottom wall 22 and a detachable cover 67 onthe outer end of the knob. In this connection it should be 4noted that the same screws 24 which hold the cover 67 in place on the outer end of the control knobalso serve to hold the knob itself to its end closure 23' and to clamp a flexible diaphragm 69 between the bottom of the cup and the cover 67.

Gas entering the diaphragm chamber through the aperture 65 reaches the outletrend 39 of the knob passageway through a branch passage 70 extending axially through the cylindrical side wall of the knob, and the filtered gas, of course, discharges from the interior of the knob into the outlet branch passage 41 inthe valve body from whence it flows to the pilot burner.

The tendency for the pressure ofjgas entering the diaphragm chamber to flex the diaphragm away from the bottom wall 22 of the knob is yeldingly resisted by a compression spring 72 inside the filter cartridge and confined between the bottom wall 22 and an enlarged head 73 on a stem 74 projecting forwardly through the hole 65 in the bottom wall of the knob and having its forward extremity riveted or otherwise fixed to the central portion of the diaphragm as at 75.. The compression spring 72 has its forward convolution relatively closely encircling the head of a bushing 77 threaded into the bottom wall 22 of the knob and in which the hole 65 is formed. The head of this bushing thus provides a valve seat cooperable with aA conically surfaced valve element 78 fixed on the stem 74 to move toward the seat in response to an increase in gas pressure against the underside of the diaphragm, against the opposition of the compression spring 72, to restrict the aperture in the bushing and consequently meter the flow of gas4 outY of the knob to thepilot burner. The compression spring 72, of course, is so balanced against the gas pressure in the diaphragm chamber that when the desired gas pressure obtains for the pilotburner the'valve element 78 is held off of the seat provided by the head of the bushing 77 During fluctuations in gas pressure, however, the valve element 7S will be moved either toward or from its valve seat depending upon whether the pressure of the gas is above or below the desired value for the pilot burner.

The advantage of incorporating a pressure responsive regulator in the control knob to regulate the pressure of the gas being supplied to the pilot burnerl is that it assures that the flame of the pilot burner Will`remain in avery stable state of ignition, exercising the best possible influence upon the hot junction 13 of the thermocouple 12 to obtain more accurate operation of the thermoelectric shut off valve than is now feasible.

From the foregoing description taken in connection with the accompanying parent that this invention greatly improves the operation of a thermoelectric automatic shut off valve for gas furnaces and other appliances by reason of the accurate control it exercises over the supply of gas to the pilot burner of the installation. Y

What I claim as my invention is:

l. A regulating device for controlling the diversion of gas from a main duct to an auxiliary duct, comprising: a body having a passage therethrough to form knob rotatably mounted on the exterior ofthe body with a surface on the knob in intimate contact with a mating surface on the body; said body having a pair of branch passages each having one end opening to said mating surface on the body, and covered by said drawings, it will be readily ap- "Iii knob, y.one `of-f'said ibranch Ipassages being-atall times connected with the body passage and the other branch Vpassage being at all times connected with said auxiliary port on the body; means on the knob defining a passageway therethrough which includes the hollow interior of the control knob, said passageway having its ends opening -to said surface on the knob and registering respectively with said ends of the branch passages in the body in one position of rotation of the knob so that gas must flow from the body passage through the knob passageway to reach the auxiliary port on the body; and a filter in the hollow interior of said knob for filtering the gas flowing therethrough to the auxiliary port on the body.

2. A regulating device for controlling the diversion of gas from a main duct to an auxiliary duct connecting with a pilot burner, comprising: a lbody having a passage therethrough to form part of the main duct, and having an auxiliary port connectible with the auxiliary duct; a control knob rotatably mounted on the exterior of the body with a surface-on the knob in intimate contact with a mating surface on the body; said body having a pair of branch passages each of which has one end opening to said mating surface on the body and covered by said knob, one of said branch passages connecting with the body passage and the other branch passage connecting with said auxiliary port on the body; means on the knob defining a passageway therethrough having its ends opening to `said surface on the knob and registering respectively with said ends of the branch passages in the body in one position of rotation of the knob, so that gas from the body passage must flow through the knob passageway to reach said auxiliary port on the body; a filter in said knob passageway for filtering the gas flowing therethrough to the auxiliary port on the body; means in the knob for adjustably restricting the passageway therein; and pressure responsive means in the knob for adjusting the position of said restricting means in response to variations in the pressure of gas in the knob passageway.

3. The regulating device set forth in claim 2 wherein said restricting means comprises a valve seat in the passageway and a valve element movable toward and from said seat and yeldingly biased away from the seat; and a flexible diaphragm in the knob connected with the valve element to move the same toward said seat in response to increase in gas pressure in the knob passageway.

4. A regulating device for controlling the diversion of fluid from a main duct to an auxiliary duct, comprising: a body having a passage therethrough to form part of the main duct, and having an auxiliary port connectible with the auxiliary duct; a hollow element movably4 mounted on the exterior of the body with a surface on said element in intimate contact with a mating surface on the body; said body having a pair of branch passages each of which has one end opening to said mating surface on the body, one of said branch passages connecting with the body passage and the other branch passage connecting with said auxiliary port on the body; means on the hollow element defining a passageway therethrough having its ends opening to spaced apart areas at said surface on the hollow element and communicating respectively with said ends of the branch passages of thel body so that fluid in the body passage must flow through the passageway in the hollow element to reach said auxiliary port on the body and so that such fluid flow may be regulated by movement of Vthe hollow element; means in the passageway of said hollow element for adjustably restricting said passageway; and pressure responsive means in said hollow element for adjusting the position of said restricting means in response to variations in the pressure of fluid in the passageway of the hollowj element.

encaisse 5, A regulating` device for controlling the diversion of gas from a main duct to anv auxiliary duct, comprising: a body having a passage therethrough'to form part of the main duct, said body having an auxiliary port connectible with the auxiliary duct; a hollow control knob rotatably mounted on the exterior of the body and having a surface in intimate contact with a mating surface on the body; means on the knob defining a passageway therethrough, said passageway including the hollow interior of the knob and having. its ends opening to said surface on the knob at spacedareas thereof, one. end of the knob passage having an enlarged mouth; said bodyhaviug'a branch passage connecting with the body passage and opening to said mating surface on the body in register with the enlarged mouth of the knob passageway to supply gasto the interior of the knob, and the body having another branch passage connecting with the auxiliary port and opening to said mating surface on the body in registry with: the other end of the knob passageway so that gas from the body passage must ow through the hollow interior of the control knob to reach the auxiliary port on the body, and so that rotation oi the knob in one direction to a position producing partial misalignment between said other end of the knob passageway and the adjacent end of said other branch passage in the body eiiects metering of the flow of gas out of the knob without effecting a corresponding restriction of gas iiow into the knob; and a iilter in the hollow interior of said knob for filtering the gas before such metering of its tlow to the auxiliary port on the body.

6. A regulating device for controlling the diversion of gas from a main duct to an auxiliary duct, comprising: a body having a passage therethrough to form part of the main duct, and having an auxiliary port connectible with the auxiliary duct; a cup-shaped control knob having a bottom providing an end wall, and having a substantially cylindrical side wall; a cover detachably connected to the knob over the open side thereof so that the cover provides an end wall spaced from but opposite the end wall provided by the bottom of the cup-shaped knob; means rotatabiy mounting said cup-shaped knob on the exterior. of the body with the exterior surface of one of said end walls in intimate contact with a mating surface of the body; and an annular filter cartridge confined in the interior of said knob coaxially thereof with the ends of the iilter cartridge in sealing engagement with the end walls of the knob; said body having a pair of branch passages therein with one end of each branch passage opening to said mating surface on the body and covered by the knob, one of said branch passages communicating with the body passage and the other branch passage connecting with the auxiliary port on the body; and said knob having passages through said end wall thereof respectively aligning with said ends of the branch passages in the body in one position of rotation of the knob, one of said knob passages communicating the body passage with the interior of the knob externally of the iilter cartridge therein, and the other of said passages communicating the auxiliary port on the body with the central zone of the knob inside thc lter cartridge, so that gas from the body passage must llow through the interior of the knob and the ilter cartridge therein to reach said auxiliary port on the body.

7. The regulating device set forth in claim 6 further characterized by the provision of cooperating stops on the knob and the body for precluding rotation of the knob in one direction beyond a position at which its passages align at least partially with the branch passages inthebody, and for limiting rotation of the knob in the opposite direction at a position at which one of the knob passages is completely out of register with the adjacent branch passage in the body.

8. The regulating. device set forth in claim 7 further characterized by the fact that the knob passage leading to the space around the exterior of the filter-'cartridge has an arcuately enlarged mouth atall times registering with the end off the. adjacent` branch passage in the body so that metering' of theV flow of'gas toithei auxiliary port, effected by'rotation of the'knob't'o its tirst designated limit, takes place. solelyatf the outlet side-of the lter cartridge inthe knob.

9. A regulating device for controlling the flow of gas to a main burner and a pilot burner therefor, comprising the: combination-of.: a valve body having a main passage through which gas is supplied to the main burner and having a pilot port onl its exterior connectible with the. pilot burner;l an electromagnetic valve for controlling the iiow of gas through said main passage; a arne sensing device operated by the flame of the pilot burner for energizing said electromagnetic valve to hold the same open and thus permit the tlow of gas through said main passage as long as the pilot ilame obtains; a hollow element movably mounted on` the exterior of the valve body and' having spaced apart openings in a wall portion which engages a mating surface on the valve body, said openings being communicated with the interior of the hollow element; means defining a passageway leading from the main passage to said pilot port through said openings and the interior of said hollow element so that gasidiverted from the main passage to the pilot port must ow through-the interior of he hollow element and may be regulated by movement of the hollow element; filter means in said hollowelement for filtering the gas ilowing therethrough to the pilot port; and pressure regulating means in saidhollow element for assuring that the pilot gas pressure will be substantially uniform.

l0.. A regulating device for controlling the liow of gas to a` mainl burner and a pilot burner therefor, comprising the combination of: a valve body having a main passage through which gas is supplied' to the main burner and having a pilot port on its exterior connectible with the pilot'bumer; an electromagnetic valve for controlling the iiow of` gas through said main passage; a flame sensing device operated-by the flame of the pilot burner for energizing said electromagnetic valve to hold the same openv andrthus permit the ow of gas through said main passage as long as the pilot iiame obtains; a hollow element movably mounted on the exterior of the valve body andhaving spaced apart openings in a wall portion which engages a mating surfacey on the valve body, said openingsbeing4 communicated with the interior of the hollow element; means defining a passageway leading from the main passage to said pilot port through said openings and the interior of said hollow element so that gas diverted from the main passage to the pilot port must ow through. the interior of the hollow element and may be regulated by movement ofthe hollow element; and pressure regulating means in said hollow element for assuring that .the pressure of gas owing through said passageway therein to the pilot port will be substantially uniform.

1l. In a device for controlling the diversion of iiuid from a main duct to an auxiliary duct: a body having a passage therethrough to form part of the main duct, and having an auxiliary port connectible with the auxiliary duct; a hollow element' movably mounted on the exterior ofl the body with a surface on said element in inti- Y mate contact with a mating surface on the body; said body having a pair of` branch passages each of which has one end opening to said mating surface on the body and covered by the hollow element, one of said branch passages being at all times connected with the body passsage and thev otherA branch passage at all times connecting with the auxiliary port on the body; means on the hollow element defining a passageway therethrough having its ends opening tosaid surface on the control element and communicating respectively with said ends of the branch passages in the body sothat liuid in the body passage must ilowv serially through said tirst designated branch passage, said-passageway in the hollow element, and the other of said branch passages toreach said auxiliaryport on thebody and so that such iiuid ow may be regulated by movement of the hollow element; a lter cartridge in said passageway in the hollow element for-filtering all of the uid owing through the passageway thereof to the auxiliary port on the body; and means on the hollow element providing a detachable cover over said lter car tridge, whereby detachment of said cover renders the filter cartridge accessible for inspection and/or replacement.

12. A safety device for shutting ol the supply of gas to the main burner of a gas appliance in the event of extinction of the llame of a pilot burner for said main burner, which shut-off device comprises a valve body having an inlet passage and a burner passage communicating with said inlet passage and having an inlet pilot branch passage communicating with the inlet passage and an outlet pilot branch passage leading to a pilot port on the exterior of the body, both of said pilot branches opening to a surface on the body, a valve in said inlet passage, a flame sensing device, and means under the control of said ame sensing device for holding said valve open as long as a flame of given character obtains at the pilot burner, and a rotatable metering knob on the exterior of the valve body overlying said surface and having pilot branch passage portions therein, said knob having a surface mating with said surface on the body and to which said pilot branch passage portions open in communicating alignment with said pilot branches in the body in one position of rotation of the knob, means for preventing false safeties wherein gas iiow through said burner branch passage is interrupted because of variations in pilot iiame characteristics to which the iame sensing device responds as if the pilot ame were extinguished, said last means comprising: a filter in the interior of the knob to filter gas passing through said pilot branch passage and thus prevent solid matter in the gas from reaching the pilot burner where it would adversely affect pilot iiame characteristics.

13. A safety device for shutting off the supply of gas to the main burner of a gas appliance in the event of extinction of the flame of a pilot burner for said main burner, which shut-off device comprises a valve body having an inlet passage and a burner passage communicating with said inlet passage and having an inlet pilot branch passage communicating with the inlet passage and an outlet pilot branch passage leading to a pilot port on the exterior of the body, both of said pilot branches opening to a surface on the body, a valve in said inlet pas` sage, a llame sensing device, means under the control of said flame sensing device for holding said valve open as long as a ame of given character obtains at the pilot burner, and a rotatable metering knob on the exterior of the valve body overlying said surface and having pilot branch passage portions therein, said knob having a surface mating with said surface on the body and to which said pilot branch passage portions open in communicating alignment with said pilot branches in the body in one position of rotation of the knob, means for preventing false safeties wherein gas flow through said burner branch passage is interrupted because of variations in pilot flame characteristics to which the flame sensing device responds as if the pilot ame were extinguished, said last means comprising: pressure regulating means in the interior of said knob for assuring that the pressure of gas flowing to said pilot burner through said pilot branch passage remains substantially uniform despite uctuations in gas pressure in the inlet passage of the valve body, and at a value which assures a pilot flame of the desired character.

14. A safety device for shutting oi the supply of gas to the main burner of a gas appliance in the event of burner, which shut-onc device comprises a valve body having an inlet passage and a burner passage communicating with said inlet passage and having an inlet pilot branch passage communicating with the inlet passage and an outlet branch pilot passage leading to a pilot port on 'the exterior of the body, a valve in said :inlet passage, a llame-sensing device, means under the control of said flame sensing device for holding said valve open as long as a ame of given character obtains at the pilot burner and which yotherwise closes,.means for preventing false safeties wherein gas ilow through said branch burner passage is interrupted because of variations in pilot ame characteristics to which the llame sensing device responds asif the pilot ame were extinguished, said last means comprising: a hollow metering knob rotatably mounted on said valve body'and having pilot branch passage portions communicating with the hollow interior thereof, said .knob and valve body having mating surfaces to which their respective branch pilot passages open in communicating alignment with one another in one position of rotation of the knob, rotation of said knob to and from said position enabling regulation of the flow of gas to the pilot burner to a rate which maintains a pilot flame of the desired characteristics; and a lter in the interior of the knob to filter gas passing through said pilot branch passage and thus prevent solid matter in the gas from reaching the pilot burner where it would adversely alect pilot burner characteristics.

l5. A safety device for shutting off the supply of gas to the main burner of a gas appliance in the event of extinction of the flame of a pilot burner for said main burner, which shut-olf device comprises a valve body having an inlet passage and a burner passage communicating with said inlet passage and having an inlet pilot branch passage communicating with the inlet passage and an outlet pilot branch passage leading to a pilot port on the exterior of the body, a valve in said inlet passage, a flame sensing device, means under the control of said ame sensing device for holding said valve open as long as a flame of given character obtains at the pilot burner and which otherwise closes, means for preventing false safeties wherein gas ow through said branch burner passage is interrupted because of variations in pilot flame characteristics to which the llame sensing device responds as if the pilot flame were extinguished, said last means comprising: a hollow metering knob rotatably mounted on said valve body and having pilot burner passage portions communicating with the hollow interior thereof, said knob and valve body having mating surfaces to which their respective branch pilot passages open in communicating alignment with one another in one position of rotation of the knob, rotation of the knob to and from said position enabling regulation of the flow of gas to the pilot burner to a rate which maintains a pilot ame of the desired characteristics; and pressure regulating means in the interior of said knob for assuring that the pressure of the gas flowing to said pilot burner through said pilot branch passage remains substantially uniform despite fluctuations in gas pressure in the inlet passage of the valve body, and at a value which assures a pilot llame of the desired character.

16. A safety device for shutting off the supply of gas to the main burner of a gas appliance in the event of extinction of the flame of a pilot burner for said main burner, which shut-olf device comprises a valve body having an inlet passage and a burner passage communicating with said inlet passage and having an inlet pilot branch passage communicating with the inlet passage and an outlet pilot branch passage leading to a pilot port on the exterior of the body, a valve in said inlet passage, a tiame sensing device, means under the control of said ame sensing device for holding said valve open as long as a llame of given character obtains at the pilot burner and which otherwise closes, means for preventing false safeties wherein gas flow through said branch burner passage is interrupted because of variations in pilot flame characteristics to which the llame sensing device responds as if the pilot ame were extinguished, said last means comprising: a hollow metering knob rotatably mounted on said valve body and having pilot branch passage portions communicating with the hollow interior thereof, saidv knob and valve body having mating surfaces to whichk their respective branch pilot passages open in communicating alignment with one another in' one position of rotation of the knob, rotation of said knob to and from said posi'- tion enabling regulation of the ow of gas to the pilot burner to a rate which maintains a pilotv flame of` the desired characteristics; a filter in the interior of the knob to lter gas passing through said pilot branch passage and thus prevent solid matter in the gas fromk reaching the pilot burner Where it would adversely affect pilot amc characteristics; and pressure regulating means in the interior of said knob for assuring that the pressure of gas owing to said pilot burner through said pilot branch passage remains substantially uniform despite uctuations in gas-pressure in the inletfpassage of the valve body, and at ay value which assures a pilot flame of the desired character. K

RefcrencesfCited in the tile of this patent UNITED STATES PATENTS 1,199,486 Nauer Sept. 26, 1916 2,351,732 Y Almond et al June 20, 1944 2,373,326 Miner Apr. 10, 1945 Y 2,607,530 Eskin et al. V Aug. 19, 1952 2,642,084 Lynch June 16, 1953

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