US2851241A - Control valves for gaseous fuel burning appliances such as stoves, ranges, heaters and lamps - Google Patents

Description

Sept. 9, 1958 H. A. AKE WALLGREN CONTROL VALVES FOR GASEOUS FUEL BURNING APPLIANCES SUCH Filed Dec. 7. 1955 AS STOVES, RANGES, HEATERS AND LAMPS 4 Sheets-Sheet 1 Sept. 9, 1958 H A. AKE. WALLGR 2,851,241

CONTROL VALVES FOR GASEOUS FUEL BURNI APPLIANCES SUCH- AS STOVES, RANGES, HEATERS AND LAMPS Filed Dec. 7, 1955 4 Sheets-Sheet 2- Fig. 2

fro R/VE) A. AKE WALLGREN GASEOUS FUEL BURN 2,851,241 ING APPLIANCES sUcH AND LAMPS Sept. 9, 1958 CONTROL VALVES FOR AS STOVES, RANGES, HEATERS Filed Dec. 7, 1955 4 Sheets-Sheet 3 a [/v VENIO/Y Him/940 flm-M 6 x! A HLLGRE/ P 9, 1958 H. A. AKE WALLGREN 2,851,241

FOR BURNING AFPL CONTROL VALVES GASEOUS FUEL CE'S SUCH AS STOVES, RANGES, HEATERS AND LAMP Filed Dec. 7, 1955 I 4 Sheets-Sheet 7Q Iii Mun nited States CONTROL VALVES FOR GASEOUS FUEL BURN- ING APPLIANCES SUCH AS STOVES, RANGES, HEATERS AND LAMPS Harald Anton Ake Wallgren, Alvsjo, Sweden, assignor to Aktiebolaget Bahco, Stockholm, Sweden, a corporation of Sweden The present invention relates to a control valve for gaseous fuel burning appliances such as stoves, ranges, heaters and lamps.

The invention is especially advantageous in connection with small portable stoves as used for instance by campers. With stoves of this kind, it is very important to ration the fuel consumption as economically as possible since the capacity of the fuel container or containers of the stove is rather limited by reasons of weight and size.

Appliances of the general kind herein referred to, are conventionally controlled by needle valves. Such valves are not entirely satisfactory. The used fuel gas is under comparatively high pressure whereby it is difficult to adjust the gas feed to the burner so that the flame has exactly the desired size. Furthermore, the flame of a burner controlled by a needle valve is easily extinguished when and while it is attempted to set the valve for a very small flame.

Accordingly, one of the objects of the present invention is to provide a novel and improved control valve for appliances of the general kind above referredto, which permits conveniently and readily to adjust the burner flame to any desired size.

Another object of the invention is to provide a novel and improved control valve by means of which the flame of the burner can be adjusted to a minimum size without danger of extinguishing the flame while being so adjusted.

Another object of the invention is to provide a novel and improved control valve which permits conveniently and rapidly to adjust the burner flame to a definite minimum size and which further permits to vary said definite minimum size as desired.

A further object of the invention is to provide a novel and improved control valve, the adjustment of which is such that when and while the valve is being adjusted for or toward a minimum flame, the fuel passage of the valve is temporarily fully opened and then gradually and slowly reduced to the desired minimum fuel flow. This afiords the advantage that the full gas flow will clean the valve passages thereby assuring an unimpeded passage of the reduced flow of gas which is particularly important for the low gas pressure concomitant with a small flame.

Other and further advantages of the invention will be pointed out hereinafter and set forth in the appended claims forming part of the application.

In the accompanying drawing several preferred embodiments of the invention are shown by way of illustration and not by way of limitation.

In the drawing:

Fig. l is an isometric view of a portable stove equipped with a control valve according to the invention.

Fig. 2 is a sectional view of the control valve showing the same in its closed position. M

Fig. 3 is a similar sectional view of the valve, but showing the same set for a minimum flame. 1

Fig. 4 is an isometric sectional view of the valve' showing the same in its closed position, and

atom

Fig. 5 is a sectional view of a modification of the valve showing the same in its closed position.

Referring first to Fig. 1, the stove exemplified in this figure comprises a container 1 holding a body of liquid petroleum gas such as liquid propane, for example, the top of which container supports a burner 3, a cooking vessel support 4 and the control valve according to the invention generally designated by 2.

Turning now to Figs. 2, 3 and 4 showing one of the modifications of the valve, the valve according to these figures comprises a valve casing 35 which includes a generally cylindrical valve chamber 36. This chamber communicates with a gas inlet 18 and a gas outlet 37 ending in a nozzle 8.

The opening and closing of the valve are effected by means of a spherical valve member 5 which in the closed position of the valve is tightly seated upon a seat 6 leading into gas inlet 18. Sphere 5 is movable within a guide sleeve 7 threaded into chamber 36. The inner wall of sleeve 7 defines a frusto-conical space, the wide end of which encompasses valve seat 6. A bore 9 through the narrower part of the frusto-conical space leads to gas outlet 37 and hence to nozzle 8. The diameter of sphere 5 and the configuration of the frusto-conical space within sleeve 7 are so correlated that when sphere 5 has just left its seat by moving toward the right, an annular passage is defined by the sphere and the juxtaposed inner wall portion of sleeve 7 which permits a maximum flow of gas through the valve. As is apparent, a further movement of the sphere toward the right will gradually and slowly reduce the cross-sectional area of the passage until the sphere reaches the end position of Fig. 3 just ahead of bore 9 in which position the cross-sectional area of the passage is at a minimum and just sufl icient to sustain a desired minimum flame. In other words, a displacement of sphere 5 from the position of Fig. 2 into the position of Fig. 3 "causes a change of the flow of gas from zero value first to a maximum value and then gradually to a pre determined minimum value. Similarly a movement of the sphere from the position of Fig. 3 into the position of Fig. 2 gradually increases the flow of gas from the minimum value to the maximum value and then rapidly reduces the flow of gas from the maximum value to the zero value.

This aifords the advantage that due to the gradual reduction of the flow of gas the same can be set accurately and conveniently for a minimum flame without danger of temporarily cutting ofi entirely the flow of gas thereby extinguishing the flame. Furthermore, the full gas pressure during both the opening and the closing operation of the valve causes a flushing of the valve thereby removing all impurities that may have accumulated therein.

The position of sphere 5 within sleeve 7 is controlled by manually operable control means. These control means are shown as comprising a control rod ill the inner end of which engages sphere 5 in all positions thereof against the action of a loaded spring 10 which biases the sphere toward engagement with the inner face of rod 11. The rod is screwed into an internally threaded sleeve shaped portion 12 of the valve casing A cup 13 is threaded upon an external thread of portion 12 and provided with a hole through which rod 11 protrudes. The protruding end of the rod supports a hand wheel 14 or other suitable member for turning rod 11. The bottom 15 of cup 13 forms an abutment for an enlarged portion 16 of the rod thereby limiting the withdrawal of the rod to. a position in which sphere 5 occupies a position such that it forms together with the adjacent wall portion of sleeve 7 a very narrow annular passage for the gas which corresponds to the desired minimum flame of the burner. As is apparent, displacement of cup 13 relative to portion 12 varies correspondingly the limit position of the withdrawal of rod 11 and as a result the limit position of sphere and with it the minimum size ofthe flarne.

The valve casing is attached to fuel container 1 by' means of a threaded stud 17. The gas enters the valve through the gas inlet conduit .18,

When it is desired to increase the minimprn-fiarngeup 13 is screwed deeper upon portion 12 after previously screwing in rod 11 sufficientlylto perrnit the reguiredgro tation of cup 13 into its position deeper upon portion 1% Finally, rod :11 is screwed out again intoits new. limit p er. sition to check whether the minimum flame is increased to the desired extent. Similarly, a reduction of the mini-. mum fiame is effected by correspondingly screwing out cup 13. The check of the .changein the size of-thc flame. is again effected. by screwing rodll into its new; limit position. i i 4 i Fig. 5 shows a modificationwhichsomewhat simplifies the adjustment of the valve.

According to Fig. 5, cup 13 of the previousfigures is replaced by a bushing 19 screwed into the threaded. ,extension 12. Bushing 19 serves to receive rod llandis internally threaded; for this purpose, The inner end of the bushing 19 forms ashoulder 20 engaginga correspondingly enlarged portion 21 of rod 11 when wheel .14 is turned through an a ngle which corresponds to thesctting of bushing 19 and with it of the desired minimum flame. Asis apparent, rod 11 is compelledtofollow. a rotation of b ushing 19, when this is adjusted. If the. burner is burning while bushing,19.is adjusted, the change; of the size of the flamedue to the adjustment of-bushing. 19 can be directly observed.

By s'electing the slant of the conical surfaceinsleeve-T a very slowvariation of the size of thefiamefrom the. maximum flame tothe minimumflarnetcan be conven-. iently obtained. Furthermore, as previously .pointed 1011i, 7 the very small annular slot determining the sizeofthe gas. passage for the minirnumflame, which is obviously very. sensitive to the presen ce of dust particles androther im-. purities collecting in sleeve 7, is cleaned eachtimebyihe. full pressure of .the gas temporar-ily present whenand while sphere 5 moves through the position representing the maximum flame.

While the inventionhas been described indetail-withzrespect to certain nowprefierred.examples.and.embodiments of the invention .it, will be. understood :by those skilled in the art, after. understandingthe invention, that various changes and modifications may be made without departing from the spirit and scope of the invention and itis intended, therefore,..to coveruall such .changes -and modifications in the. appendedclaims.

What. is claimed as Tnewandndesired to be secured by- Letters Patentis:v

1. A. control valve.for.,a gaseous..fuel burninga-appliance, comprising a valve. casing. including. a valvechamber, a fuel inlet and afuel outlet communicating with said chamber, the wall surface of thescasingdefiningthe opening of said inlet. within the .charnber..constituting a valve seat, another wall surface within the casing de: fining a chamber portion of frusto-conical configuration, said chamber portion encompassing saidvalve seat .at .the. wide end of said chamberportion andcommunicatingat. a narrowed part with said outlet, .a spl: 1erical-.valve.mem-. ber freely movable within said frust'o-conicalazchamber. portion and having adiameterlessthan the-maximum diameter of said frusto-conical portion, and. control. means coacting with said .valve memberfor. limiting. move-. ment of the latter between aclosing positionirr whihxthe valve member is seatedupon. said. valveseat andia pre-v determined minimum flow position,.said latter positionlbee. ing a position anterior ofrlthenpoint atdvhichsaidicham: ber portion communicates with. the outlet wheLebyc-uponmovement of the valve member. from.its..closing posi-.; tion toward its minimum flow position the fuel flowibe-w comes first a maximum and is gradually.reducedtothe... minimum flow, said control .means.comprising an -axially.

displaceable control rod extending through the narrow si ent. eidfu stoz oui l am r. p o into ge? ment with the valve member and stop means positively limiting an outward displacement of the rod relative to the valve seat to the position in which said valve member occupies the minimum flow position, said stop means including shoulders; on; the rod and the valve casing respectively engageable; with each other to arrest further outward displacement of the rod.

2. Acontrol valve according to claim .1, wherein one of said shoulders .is'axially displaceable.

3. A control valve according to claim 1, wherein said stop means comprise a sleeve threaded in the valve casing and forming the shoulder in the. casing, said sleeve having an internal thread for receiving the correspondingly threaded control rod.

4. A control valvefor a gaseous fuel burning appliance, said valve comprising a valve casing including a valve chamber, a fuel inlet and a fuel outlet for'the passage offuel through saidchamber, the wall surface of said casing defining said inlet constituting a valve seat, aguide sleeve-fitted in. said chamber, theinterior of said sleeve communicating with said gas outlet, the inner wall of said sleeve defining a conical surface-inwardly tapered continuously from said seat toward said outlet, the wide end of said conical surface circumscribing said valve seat, a spherical valve closure member freely axially movablewithin said sleeve, said closure member coacting with said seatand having a diameter less than the diameter at the wide-end of said conical surface, but larger than the diameter of the narrow end of the.conical surface,--a:control -rod;rotatably-disposed in said casing for axia lly-- displacing said rod byrotating the same, said rod extending into said sleeve from the narrow end thereof-and coactingwith said closure member for positively limiting the innermost position of the said member within the sleeve relative to the narrow end thereof by the axiakposition of said rod, spring means urging the closure member continually into abutment with the end of the rodin the sleeve, and axially adjustable stop means mounted onv the casing and engageable with said rod for positively limiting the withdrawal thereof from the sleeve to'a selected outer end position whereby upon withdrawal of the rod from the positionholding the closuremember againstits seat toward and into said end position the passagearea for-the gas through the sleeve first increases rapidly -to arnaximum and then decreases slowly and gradually -to-a-- minimum in-said end position of the closure member dueto the decreasing differential between the diameters of the conical surface and the closure member.- respectively.

5.--A'-control valve according to claim 4, wherein said adjustable stop means comprise.an abutment member SUPPOI'tGd-bYlthB casing-.and'displaceable parallel to the rod movement and a shoulder on the rod engageable with said, abutment member to limitthe withdrawal. of the rod at said end position.

6. A control valve according to claim 4, wherein said adjustablctstop meanscomprise a setting sleeve fitted in the casing axially adjustable relative thereto and receiving the .rod. axially adjustable relative tothe sleeve for selectively displacing the setting sleeve jointlywith thev rod to vary the selected end position of the rod and displacing the rod relative to thesetting sleeve tov move the rodinto said end position, said rod'having a shoulder thereon engageable with'said setting sleeve to arrest the rod in said end position.

7. A control valve according to claim 4, wherei.n said adjustable stop 'means comprise an externally and inter.- nally threaded setting sleeve'threaded into the casing co axially with-said rod and receiving the rod for selectively displacing the setting sleeve jointly withthe rod to vary the'selecte'd end position'of the rod and displacing the rod relative to the'setting sleeve to move the rod into the end position, said rod having a shoulder thereon engageable with said setting sleeve to arrest the rod in said end position.

References Cited in the file of this patent UNITED STATES PATENTS Wemmer Feb. 4, 1902 I-Iiller Jan. 26, 1904 Smith May 4, 1926 Forest Dec. 8, 1931 10

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