US3230973A - Snap acting valve for gas burners and the like - Google Patents

Description

Jan. 25, 1966 R, SCHQRK ETAL 3,230,973

SNAP ACTING VALVE FOR GAS BURNERS AND THE LIKE Filed June lO, 1965 2 Sheets-Sheet 1 F76. F/G. 4

w ,f3 f/f mn\\ 77 a /f/a in@ IIIIFr Jan 25, 1966 R. scHoRK ETAL 3,230,973

SNAP ACTING VALVE FOR GAS BURNERS AND THE LIKE Filed June lO, 1963 2 Sheets-Sheet 2 F76. 7 F7C?. /0

United States Patent O 3,230,973 SNAP ACTING VALVE FR GAS BURNERS AND THE LIKE Rudolf Schot-lr, Wem-au, and Kurt Steinhardt, Stuttgart- Sllenbuch, Germany, assignors to Junkers & Co.

G.m.b.H., Wernan, Germany Filed June 10, 1963, Ser. No. 286,753 Claims priority, application Germany, June 9, 1962, J 21,919, J 21,920; Feb. 25, 1963, J 23,241 5 Claims. (Cl. 137-625.253)

The present invention relates to valves in general, and more particularly to a valve which is especially suited for delivering controlled quantities of fuel to multi-stage gas burners. Such burners may be used in gas ranges, in water heaters and in similar appliances.

It is known to provide a valve in the path of fuel ow to the main burner of a water heater and to construct the valve in such a way that it may deliver a small stream of gaseous fuel prio-r to permitting the passage of a larger fuel stream. In other words, when the valve is actuated,

it permits a small stream of gaseous fuel to ow towardv the burner and, once this small stream is ignited, the valve permits a larger stream to ow and to be ignited by the smaller fuel stream. A serious drawback of conventional valves of this general character is that the-re is a delay between the time when the valve starts the discharge of a smaller stream and the time when the small stream is permitted to flow at full capacity. Such construction is particularly unsatisfactory when the so-called Wobbe number of the gas is high. The Wobbe number is determined by dividing the caloric value with the square root 0f the density of the gas.

Accordingly, it is an important object of our invention to provide a very simple valve which is consrtucted and assembled in such a way that the flow of one or more small streams of gaseous fuel to the burner may be increased instantaneously or nearly instantaneously from zero to full capacity. l

Another object of the invention is to provide a valve of the just outlined characteristics wherein the flow of a large gas stream may also increase from zero to full capacity practically without any loss in time and in timed relation to the full-capacity iiow of one or more smaller gas streams.

A further object of the invention is to provide a valve of the just outlined type wherein the customary sealing element is mounted in such a way that it actually assists in increasing the rate of fuel tiow from Zero to full capacity without any or with exceptionally short delay.

An additional object of the invention is to provide a gas valve which embodies the above outlined features and which may be combined with conventional multi-stage burners without necessitating any changes in the construction of such burners.

With the above objects in view, one feature of our invention resides in the provision of a valve which is especially suited for controlling the flow of fuel to a multistage gas burner. The valve comprises a first valve member having a bore bounded by an internal surface and a second valve member having a peripheral surface spaced from and defining an annular gap with the internal surface of the stationary valve member. The second valve member is movable axially in a rst direction from the one toward the other end of the bore into a valve closing position and in a second direction counter to such first direction to assume a valve opening position. One of the valve members has at least one bypass opening which communi-Cates with the gap when the second valve member assumes its valve closing position, and the valve further comprises a normally compressed elastic sealing ring `which is received in the gap and which is secured to the ICC other valve member so as to engage the surface of the one valve member between the bypass opening and one end of the bore when the second valve member assumes its valve closing position. In accordance with our invention, the surface of the one valve member (i.e., of that valve member which is provided with one or more bypass openings) has a first annular portion adjacent to the bypass opening and a second annular portion immediately preceding the first annular portion as seen in the direction of movement of the second valve member to its valve opening position.. The lirst annular portion is more distant from the other valve member than the second annular portion so that the second annular portion constitutes an obstruction to movement of the second valve member and that, when the second valve member moves in a direction to assume its valve opening position, the ring is compressed more while engaging the second annular portion and is then permitted to expand toward the first annular portion with simultaneous reduction in its resistance to movement of the second valve member to its valve opening position whereby the bypass opening is exposed almost instantaneously in an intermediate position of the second valve member and permits a small stream of fuel to flow to the burner at full capacity. In its valve opening position, the second valve member permits a larger stream of gaseous fuel to ow from the one to the other end of the bore in the stationary valve member, and such large stream may be ignited by fuel which was delivered through the bypass opening.

The novel features which are considered as characteristie of the invention are set forth in particular in the appended claims. The improved valve itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood from the following detailed description of certain specific embodiments with reference to the accompanying drawings, in which:

FIG. l is a fragmentary axial section through a valve which embodies one form of our invention and whose movable valve member is shown in valve closing position;

FIG. 2 is a similar section showing the movable valve member in an intermediate position in which a small stream of gaseous fuel is permitted to flow through a bypass opening provided in the stationary valve member;

FIG. 3 is another fragmentary axial section showing the movable valve member of FIGS. l and 2 in valve opening position;

FIG. 4 is a fragmentary axial section through a modied valve Whose movable valve member is provided with a bypass opening and is shown in valve closing or sealing position;

FIG. 5 illustrates the structure of FIG. 4 with the movable valve member in an intermediate position in which the bypass opening permits a small stream of fuel to flow to the burner;

FIG. 6 illustrates the structure of FIGS. 4 and 5 with the movable valve member in a valve opening position in which the valve permits a large stream of fuel to flow to the burner;

FIG. 7 is a fragmentary axial section through a third valve which is similar to the valve of FIGS. 1 to 3 and whose valve member is shown in valve closing position;

F IG. 8 illustrates the structure of FIG. 7 with the movable valve member in an intermediate position in which a small stream of fuel is permitted to ow through a bypass opening provided in the stationary valve member;

FIG. 9 illustrates the structure of FIGS. 7 and 8 with the movable valve member in valve opening position;

FIG. l0 is a fragmentary axial section through a fourth valve which is similar to the valve of FIGS. 4 to 6 and whose movable valve member is shown in one of its end positions in which the valve is closed so that the source of gaseous fuel is sealed from the burner;

FIG. l1 is a similar fragmentary section showing the movable valve member of FIG. l in an intermediate position in which a bypass opening provided in this valve member permits a small stream of fuel to flow to the burner; and

FIG. 12 illustrates the structure of FIGS. 10 and l1 with the movable valve member in valve opening position in Which it permits a large stream of fuelto flow to the burner.

Referring to the drawings, and first to FIGS. 1 to 3, there is shown a valve which is especially suited for selectively delivering a large stream `or one or more smaller streams of fuel to a multi-stage gas burner. This valve comprises a stationary valve member which defines an annular seat 11, and a movable valve member 12 which carries an annular gasket 13 adapted to move into and out of sealing engagement with the annular end face 11a of the seat 11. The movable valve member 12 comprises an extension 14 which is normally received with play in a through bore 15 of the stationary valve member 10 so that the internal surface of the valve member 1i) which surrounds the bore 15 defines with the peripheral surface 14a of the extension 14 an annular gap 16 which accommodates a portion of an annular sealing ring 17, the latter consisting of elastically deformable material (e.g., rubber or synthetic plastic) and being dimensioned in such a way that it is compressed by the internal surface of the stationary valve member 10 to provide a reliable seal between the lower or intake end of the bore 15 and a bypass opening 18 which communicates with the upper or discharge end of the bore 15 via gap 16 when the valve member 12 assumes the valve closing position of FIG. l. The bypass opening 13 comprises a radial section and an axially extending section, and the latter communicates with a shallow recess 11b which is surrounded by the seat 11 and which communicates with the upper end of the bore 15. The inner portion of the ring 17 is received in an annular groove 1411 provided in the peripheral surface 14a so that the ring 17 is compelled to share axial movements of the valve member 12 when the latter is caused to leave the position of FIG. 1 and to advance through the intermediate position of FIG. 2 toward and into the valve opening position of FIG. 3. In other words, the valve member 12 is movable in a first direction axially of and from the upper toward the lower end of the bore 15, and in a second direction counter to such first direction and in a sense to withdraw its extension 14 from the bore 15, see FIG. 3.

In accordance with an important feature of our invention, the stationary valve member 10 is formed with an annular obstruction or bead which is closely adjacent to the bypass opening 18 and which is located ahead of this opening, as seen in the direction in which the valve member 12 moves when its extension 14 is being with drawn from the bore 15. The obstruction 20 is of semicircular cross-sectional outline and is bounded by a convex surface which includes a lower section 21 normally abutting against the ring 17 in the valve closing position of the member 12 and an upper section 22 which is immediately adjacent to the opening 18. The sections 21, 22 together constitute a portion of the internal surface of the valve member 1t), and this surface is nearer to the peripherial surface 14a than a second surface portion which extends from the surface portion 21, 22 toward the upper end of the bore 15.

The valve of FIGS. l to 3 operates as follows:

In FIG. 1, the valve member 12 is shown in valve closing position in which its gasket 13 abuts against the end face 11a of the seat 11 and in which its ring 17 abuts against the internal surface of the valve member 10 including the section 21 so that both ends of the bypass opening 18 are sealed. In other words, the horizontal symmetry plane of the ring 17 is located at a level below the apex of the obstruction 20. At the same time, the gasket 13 cooperates with the ring 17 to provide a reliable seal against escape of fuel which tends to flow upwardly, as viewed in FIG. 1, through the lower end of the bore 15, through the gap 16, and toward the upper endof the bore 15. It is assumed that the lower end of the bore 15 is connected with a source of gaseous fuel, such as a supply conduit 19a leading into a gas range, and that the seat 11 is surrounded by the intake end of a connecting conduit 10b whose discharge end leads into a multi-stage gas burner, not shown.

When the user thereupon decides to admit a small stream of fuel to the conduit 10b, the valve member 12 is caused to move axially of the bore 15 (for example, in response to axial or rotary movement of a knob or auother suitable handgrip means) and the ring 17 is compelled to pass along the obstruction 2@ to be subjected to increased compression so that it offers greater resistance to axial movement of the valve member 12. However, as soon as the center of the ring 17 moves upwardly and beyond the innermost zone of the obstruction 20, it is subjected to lesser compression and its resistance to withdrawal of the valve member 12 from the bore 15 decreases suddenly so that, and if the valve member 12 is moved with unchanging force, it advances the ring 1'7 rapidly along and beyond the opening 18 and into the intermediate position of FIG. 2 in which a small stream of fuel (arrows 10c) is free to ow at full capacity through the bypass opening 18, through the recess 11b and into the conduit 10b to be ignited in a first stage of the burner. The gasket 13 moves away from the end face 11a as soon as the valve member 12 leaves the position of FIG. 1 so that the discharge end of the opening 18 is exposed and fuel fiowing through the lower end of the bore 15 is free to flow through the opening 1S and into the conduit 10b. The valve member 12 may remain in the position of FIG. 2 for a predetermined period of time in order to permit satisfactory ignition of fuel in the first stage, whereupon the operator continues to move this valve member in a direction to withdraw the extension 14 from the bore 15 until the member 12 reaches the valve opening position of FIG. 3 in which the ring 17 is located at a level above the recess 11b so that a large stream of fuel may flow through the upper end of the bore 15 (arrow 10d) and into the connecting conduit 1b to enter the burner and to be ignited by the burning smaller fuel stream.

The situation is reversed when the valve member 12 is returned to the position of FIG. 1. In the first stage of such movement, the ring 17 enters the upper end of the bore 15 and is subjected to gradual compression while moving along the inclined uppermost portion 111e of the internal surface of the stationary valve member 11i. Once it engages the valve member 10 at a level below the surface portion 10e, the ring 17 is sufficiently compressed to prevent escape of fuel through the upper end of the bore 15, and this ring will seal the lower end of the bore from the bypass opening 18 as soon as it reaches the upper section 22 of the obstruction 20. In response to further movement of the valve member 12, the ring 17 moves along the sections 22, 21 and enters the lower portion of the bore 15 wherein it remains at the time the gasket 13 reaches the end face 11a to provide a satisfactory seal against escape of any fuel into the connecting conduit 10b.

It will be noted that the improved valve insures practically instantaneous ow of a small gas stream from the conduit 11M, through the gap 1o and bypass opening 1S and into the conduit 10b as soon as the elastic ring 17 moves beyond the annular obstruction 20. The valve will permit a small stream of gas to flow through the opening 18 with practically instantaneous transition from a sealing to an exposing position of the valve member 12 if the latter is biased by a suitable spring, not shown, which is free to expand substantially without any loss in :cent'to the end portion 110e.

periphery of a circle which is adjacent to the section 22.

The rate at which the gas flows to the conduit b when the valve member 12 assumes the intermediate position of FIG. 2 will also depend on the cross section of the bypass openingor openings 18. In certain instances, we may provide suitable nozzles which are inserted into the opening or` openings 18 to produce the well known venturi effect.

When.the ring 17 moves along the end portion 10e of the internal surface bounding the bore 15, it is permitted to expand very rapidly and its expansion produces a component of force which tends to expel the extension 14 lfrom the bore. Thus, the effect of the end portion lite is the same as that of the section 22.

The conduits 10a, 10b were omitted in FIGS. 2 and 3 for the sake of clarity. The valves of FIGS. 4-12 are connected with similar conduits, and it is always assumed that the conduit 10a contains a supply of compressed gaseous fuel and that the conduit 10b connects vthe valve with a multi-stage gas burner.

FIGS. I4 to 6 illustrate anmodiiied valve whose parts are videntified by the numerals used in FIGS. l to 3 but each "precededfby a digit 1. The interal surface of the stationary valve member 110 which'surrounds the bore 115 is Vformed' with an annular groove 114b arranged to receive a portion of a compressed sealing ring 117, and this ring abuts against the peripheral surface 11441 of the extension 114.which forms part of a movable valve member 112. In the valve closing position of FIG. 4, the gasket I113 abuts against the end face 111a of the valve seat 111,

and the ring 117 abuts against the first section 121 of the surface on an annular obstruction or bead 120 which is provided onl the extension 114 and whose second surface .section 122is adjacent to the discharge end of a bypass opening 118 provided in the extension 114 and comrnunicating with the annular gap 116. The opening 118 communicates with the lower vend of the bore 115 but is free to communicate with the recess 111b as soon as the valve `member 112 is moved to the intermediate position of FIG. 5 in which the-ring 117 abuts against that zone of the peripheral surface 114a which is immediately adja- A small stream of gas is then free to iiow in the direction indicated by arrows 110C.

'When the valve member 112 is moved to the valve opening position of FIG. 6, a large stream of gas ilows in the direction indicated by an' arrow 11051 and the ring 11'7 is free to'expand because the extension 114 is moved .above the level of the groove 114b. i

When the valve member 112 moves upwardly, a

-viewed in FIG. 4, the ring 117 is compressed rst by the .surface section'121 and thereupon by the surface section A122,'but is permitted to expand gradually while in engage- -ment with the section 122. Such expansion is terminated when the obstruction 120 passes beyond the ring and,

while the ring engages the section 122, its resistance to movement of the member 112 to the valve opening position of FIG. 6 decreases suddenly so that the discharge end of the bypass opening 113 is exposed almost in- ;stantaneously to deliver a small stream of fuel to the non- `illustrated multi-stage burner wherein the fuel is ignited inthe well known manner, for example, by a pilot light or in another suitable way.

. A second sudden drop in resistance which the ring `117 offers to withdrawal of the extension 114 from the .bore 115 takes `place when the surface portion 110e :moves upwardly and beyond the position of FIG. 5. This effect is the same as when the ring 117 engages the section 122, i.e., the ring is permitted to expand d very rapidly and its expansion produces a component of force which is parallel with the axis of the extension 114 and which will tend to push the extension 114 out of the bore 115.

FIGS. 7 to 9 illustrate a third valve wherein all parts analogous to those described in connection with FIGS. l to 6 are identified by the numerals used in FIGS. l to 3 but each preceded by the digit 2. In this valve, the obstruction 20 is replaced by a different obstruction 230 which assumes the form of an annular depression or groove machined into the internal surface of the stationary valve member 210 and communicating with the gap 216. The bypass opening 218 communicates with the depression 230 and with the annular recess 211b of the valve seat 211. A portion of the sealing ring 217 is accommodated in an annular groove 214b which extends inwardly from the peripheral surface 214e of the extension 214 forming part of the movable valve member 212. In the' valve closing position of the member 212 (FIG. 7), the gasket 213 abuts against the end face 211a of the valve seat 211 and the compressed elastic ring 217 bears against the internal surface of the valve member 210 just below the annular depression 230. Thus, the intake end of the bypass opening 21S is sealed from the lower end of the bore 215, and the discharge end of the opening 218 is simultaneously sealed from the burner by the gasket 213 which abuts against the end face 2:11a. The horizontal symmetry plane of the ring 217 is then located at a level below the lower edge of the depression 230.

When the Valve member 212 is moved toward the intermediate position of FIG. 8, the ring 217 expands into the depression 230 and continues to seal the bypass opening 213y from the lower end of the bore 215. However, as the member 212 continues to move toward the position of FIG. 8, the ring 217 is permitted to expand suddenly as soon as it reaches the surface 210e which constitutes the upper zone of the internal surface surrounding the bore 215 so that the intake end of the opening 213 is exposed and permits a small stream of fuel (arrows 210C) to ow toward the burner. This intermediate position of the valve member 212 is shown in FIG. 8. The lower portion of the surface 210e is nearer to the peripheral surface 214a than the upper portion of the surface 210e so that the effect is the same as that of the obstruction 20 or 120. The depression 230 assists the lower portion of the surface 210e to increase the resistance of the ring 217 against withdrawal of the extension 214 from the bore 215, i.e., the force which moves the valve member 212 must overcome the resistance of the ring 217 when the latter extends into the depression 230 by compressing the ring so that it can move along the annular edge between the wall bounding the depression 230 and the lower end of the surface 210e. As the ring 217 expands while moving along the outwardly diverging portion of the surface 210e, its expansion produces a component of force which will tend to move the valve member 212 upwardly toward the valve opening position of FIG. 9 in which a large stream of gaseous fuel is permitted to liow through the bore 215 and through the recess 211b (arrow 210d) toward the non-illustrated burner.

The bypass opening 218 comprises a radial section which extends outwardly from the bottom zone of the depression 230 and an axial section which communicates with the radial section and with the recess 211b inwardly of the seat 211. If the depression 230 is comparatively deep, the radial section of the bypass opening 218 may be dispensed with so that the axial section provides a direct channel between the depression and the recess 211k.

Referrring finally to FIGS. l0 to l2, there is shown a fourth valve which is analogous to that of FIGS 7 to 9 used in FIGS. l to 3 but each preceded by a digit 3. The

annular depression 330 is provided in the peripheral surface S14-a ofy the extension 314, and this depression communicates with one or more radial bypass openings 31S machined into the extension 31d of the movable valve member 312 and communicating with the lower (intake) end of the bore 31S. The gap 316 accommodates a portion of a compressed elastic sealing ring 317 which extends into an annular groove 314b provided in the internal surface of the stationary valve member 3ft). The construction of the seat 311 and of the gasket 313 is the same as in FGS. 1 to 9.

In the valve closing position of the valve member 312 (FIG. l), the ring 317 bears against a cylindrical surface portion of the extension 314 and thereby seals the discharge end of the bypass opening 318 from the recess 31112. When the valve member 312 then moves toward the intermediate position of FIG. l1, the ring 317 enters the depression 330 and is thereby permitted to expand while continuing to seal the opening 318 from the recess 311k. In response to further withdrawal of the extension 314 from the bore 3&5, the ring moves along the upper portion of the downwardly and inwardly diverging surface 310e and is compressed just prior to renewed expansion as it moves beyond the position of FIG. 1l and toward the valve opening position of FIG. l2 in which it permits a large stream of gaseous fuel (arrow 310d) to fiow toward the burner. The arrows 310C illustrate in FlG. l1 the direction of fuel flow when the discharge end of the bypass opening 318 is permitted to communicate with the recess 311b.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A valve, particularly for controlling the fiow of fuel to a multi-stage gas burner, comprising a first valve member having a b-ore with a first and a second end and an internal surface surrounding said bore; a second valve member having a peripheral surface spaced from and defining an annular gap with said internal surface, said second valve member being movable axially in a first direction from t-he first toward the second end of said bore into a valve closing position and in a second direction counter t-o said first direction to assume a Valve opening position, one of said valve members having an annular depression communicating with said gap and a bypass opening communicating with said depression, said annular depression having a predetermined width in the axial direction of said second member; and a normally compressed elastic sealing ring received in sa-id gap and secured to the other Valve member so as t-o engage the surface -of said one valve member between said opening and one end of said bore when the second valve member assumes said valve closing position, said sealing ring having a width in said axial direction greater than said width of said depression, the surface of said one valve member having a first annular porti-on adjacent to said depression and located between said depression and the other end of said bore and a second annular portion separated from said depression by said first annular portion, said second annular portion being more distant from said other valve member than said first annular portion so that when the second valve member moves in said second direction, the ring expands into said depression entirely closing and thereby sealing the same, is then compressed while engaging said first annular portion, and is permitted to expand suddenly toward said second annular portion with smultaneous sudden reduction in its resistance to movement of the second valve member in said second direction.

2. A valve, particularly for controlling the flow of fuel to a multi-stage gas burner, comprising a first valve member having a bore with an intake end and a discharge end and an internal surface surrounding said bore; a second valve member having a peripheral surface spaced from and defining an annular gap with said internal surface, said second valve member being movable axially in a first direction from the discharge end toward the intake end of said bore into a valve cl-osing position and in a second direct-ion counter to said first direction to assume a valve opening position, said first valve member having an annular depression provided in said internal surface and communicating with said gap intermediate t-he ends of said bore and a bypass opening having an intake end communicating with said depression, said annular. depression having a predetermined width in the axial direction of said second member, said internal surface having a first annular portion immediately adjacent to said depression and located between said depression and said discharge end and a second annular portion immediately adjacent to said first annular portion and located between the discharge end and said first annular portion, said seeond annular .portion being more distant from said second valve member than said first annular portion; and a normally compressed elastic sealing ring received in said gap and secured to said second valve member to engage said internal surface intermediate said depression and the intake end of said bore when the second valve member assumes said valve closing position, said seal-ing ring having a width in said axial direction greater than said width of said depression, said ring being first caused to expand while entering said depression entirely closing and thereby sealing the same when the second valve member moves in said second direction and the ring Ais Vthereupon compressed while moving along said first annular portion prior to sudden expansion tow-ard said 'second annular portion to reduce its resistance to lmovement of the second valve member in said second direction.

3. A Valve as set forth in claim 2, wherein said bypass opening has a second end which communicates with vthe discharge end of said bore in all positions of said second valve member. Y

4. A valve, particularly for controlling the flow of fuel to a multi-stage gas burner, comprising a rst valve mem ber having a bore with an intake end and a discharge end and an internal surface surrounding said bore; a second valve member having a peripheral surface spaced from and defining an annular gap with said Ainternal surface, said second valve member being movable axially in a first direction from the discharge end toward the intake end of said bore into a valve closing position and in a second direction counter to said first direction to assume a valve opening position, said second valve member having an annular depression provided in said peripheral sur face and communicating with said gap intermediate the ends of said bore and a bypass opening having a discharge end communicating with said depression, Vsaid annular depression having a predetermined width in the axial direction of said second member, said peripheral surface having a first annular portion immediately adjacent to said depression and located between said depression and the intake end of said bore and a second annular portion immediately adjacent to said first annular portion and located between the intake end of said bore and said first annular portion, said second annular portion being more distant from said internal surface than said first annular portion; and a normally compressed elastic sealing ring received in said gap and secured to said first valve member to engage said peripheral surface intermediate said depression and the discharge end of said bore when the second valve member assumes said valve closing position, said sealing ring having a Width in said axial direction greater than said Width -of said depression, said ring being rst caused to expand into said depression entirely closing and thereby sealing the same While the second valve member moves in said second direction, to thereupon undergo compression While in engagement with said iirst annular port-ion, and to expand suddenly toward said second annular portion with simultaneous reduction in its resistance to movement of the second valve member in said second direction so that the discharge end of said bypass Aopening is suddenly free to communicate with the discharge end of said bore.

5. A valve as set forth in claim 4, wherein said bypass opening has a second end which communicates with the E@ intake end of said bore in al1 positions -of said second vaive member.

References Cited by the Examiner UNITED STATES PATENTS 820,178 5/1906 Buerkle 137-625.26 2,542,390 2/1951 Brown 137-625-48 2,574,851 11/1951 Wagner 137-6253 2,693,201 11/1954 Page 137-625-33 X FOREIGN PATENTS 639,538 4/ 1962 Canada.

M. CARY NELSON, Primary Examiner.

Claims (1)

1. A VALVE, PARTICULARLY FOR CONTROLLING THE FLOW OF FUEL TO A MULTI-STAGE GAS BURNER, COMPRISING A FIRST VALVE MEMBER HAVING A BORE WITH A FIRST AND A SECOND END AND AN INTERNAL SURFACE SURROUNDING SAID BORE; A SECOND VALVE MEMBER HAVING A PERIPHERAL SURFACE SPACED FROM AND DEFINING AN ANNULAR GAP WITH SAID INTERNAL SURFACE, SAID SECOND VALVE MEMBER BEING MOVABLE AXIALLY IN A FIRST DIRECTION FROM THE FIRST TOWARD THE SECOND END OF SAID BORE INTO A VALVE CLOSING POSITION AND IN A SECOND DIRECTION COUNTER TO SAID FIRST DIRECTION TO ASSUME A VALVE OPENING POSITION, ONE OF SAID VALVE MEMBERS HAVING AN ANNULAR DEPRESSION COMMUNICATING WITH SAID GAP AND A BYPASS OPENING COMMUNICATING WITH SAID DEPRESSION, SAID ANNULAR DEPRESSION HAVING A PREDETERMINED WIDTH IN THE AXIAL DIRECTION OF SAID SECOND MEMBER; AND A NORMALLY COMPRESSED ELASTIC SEALING RING RECEIVED IN SAID GAP AND SECURED TO THE OTHER VALVE MEMBER SO AS TO ENGAGE THE SURFACE OF SAID ONE VALVE MEMBER BETWEEN SAID OPENING AND ONE END OF SAID BORE WHEN THE SECOND VALVE MEMBER ASSUMES SAID VALVE CLOSING POSITION, SAID SEALING RING HAVING A WIDTH IN SAID AXIAL DIRECTION GREATER THAN SAID WIDTH OF SAID DEPRESSION, THE SURFACE OF SAID ONE VALVE MEMBER HAVING A FIRST ANNULAR PORTION ADJACENT TO SAID DEPRESSION AND LOCATED BETWEEN SAID DEPRESSION AND THE OTHER END OF SAID BORE AND A SECOND ANNULAR PORTION SEPARATED FROM SAID DEPRESSION BY SAID FIRST ANNULAR PORTION, SAID SECOND ANNULAR PORTION BEING MORE DISTANT FROM SAID OTHER VALVE MEMBER THAN SAID FIRST ANNULAR PORTION SO THAT WHEN THE SECOND VALVE MEMBER MOVES IN SAID SECOND DIRECTION, THE RING EXPANDS INTO SAID DEPRESSION ENTIRELY CLOSING AND THEREBY SEALING THE SAME, IS THEN COMPRESSED WHILE ENGAGING SAID FIRST ANNULAR PORTION, AND IS PERMITTED TO EXPAND SUDDENLY TOWARD SAID SECOND ANNULAR PORTION WITH SIMULTANEOUS SUDDEN REDUCTION IN ITS RESISTANCE TO MOVEMENT OF THE SECOND VALVE MEMBER IN SAID SECOND DIRECTION.

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