US1548654A - Automatic gas cut-off - Google Patents

Description

Aug. 4, 1925. 1,548,654

- T. H. BOYD y AUTOMATIC GAS CUT-OFF Filed Sept. 25, 1924 Y un.. x un. l

Patented Aug. 4, lgt:

UNITED STATES THOMAS H. BOYD, OF PAWHUSKA, OKLAHOMA.

AUTOMATIC GAS CUT-OFF.

Application filed September 25, 1924. Serial No. 739,909.

fo all cof/'20m` t may concern.'

Be it known that I, THOMAS H. Born, a citizen of the United States, residing at lawhuska, in the county of Osage and State of lklahcma, have invented certain new and useful Improvements in Automatic Gas Cut- Offs, of which the following is a specification.

The present invention appertains to improven'ients in that type of safety appliances generally known as automatic cut-offs designed'for automatically cutting oft the flow of gas when the pressure in the supply line falls below a predetermined limit or is temporarily interrupted, and which remains closed upon an increase or renewal of the pressure.

1t is quite generally known that the pressure supply of gas for heating or illuminating` purposes, whether natural or artificial, is subject to fluctuation from time to time, very frequently resulting in discontinuance of the operation of the burners and when the pressure supply becomes normal again thegas is allowed to escape. Each year many lives are lost from asphyxiation and serious damage to lives and property is occasioned by explosions which are due to this uncertainty of operation of the gaseous flow. In the ordinary household small children very often turn on the gas jets of a gas stove which goes unnoticed until a large amount has. escaped. In such instances unless the precautions are taken to clear the gas filled rooms, grave likelihood of injury from eX-l plcsion or suffocation is encountered.

Many devices have been proposed heretofore for the purpose of elimination of the dangers aforesaid. In the majority of instances, however, the devices are expensive. complicated in structure, and therefore liable to get out of order, diliicult to install and otherwise objectionable, and it has been my aim to devise under these conditions a simple, unitary device, capable of being manue factured cheaply, yet very eicient in action.

by children who may be tempted to tamper with the device.

The invention is characterized as'to nov elty by the provision of a double unbalanced valve, so-called7 which is so arranged as to be maintained in open position by the normal ranges of gas pressure acting` in one direction but when closed is held so by the renewal pressure following` a drop thereof, acting in the opposite direction; and further by thev provision of a manually operable relief valve which causes an unbalancing of the opposing pressures, functioning to again open the valve.

Other objects and advantages of the'invention will be hereinafter set forth and the novel features thereof defined by the appended claims.

In ,the drawing:-

Figure l is a perspective view of an ordinary gas stove having my safety appliance in position thereon;

Figure 2 is a vertical sectional view through the automatic cut-off device;

Figure is a horizontal sectional view line 3-3 of Figure 2;

Figure e is a sectional view ofthe retainer cap forming a part of the relief valve for the cut-oft' device;

Figure 5 is a sectional view of the nipple or hoc y portion of the relief valve;

Figure 6 is a detail view' of the relie-f valve and jam nut; i

Figure 7 is a detail view of the spring for the relief valve shown in Figure 6; and

Figure 8 is a modified form of valve member which may be used in connection with this appliance.

Like reference characters designate corresponding parts throughout the several views. t

Referring to the drawing and specifically describingT the invention,'l designates the casing of the valve device which is provided at its lower end with aclosure 2 having a threaded neck 3 with which the gas supply conduit t is adapted to be connected. At the top the casing 1 is provided with a remoih able cap 5 which has threaded connection with the casing and which is formed with a wrench hold boss 6 havinga bushing? which extends through the cap and depends into the interior of the casing` a suitable distance, as indicated at 8, to form a guide, the

taken about on the plane indicated by the Il (l the valveof the reliedevice'is open.

function of which will be more apparent as this description proceeds.

Interiorly the casing 1 is formed with spaced partitions 9, 9 which divide the cas ing into the entrance chamber a, the main or intermediate chamber and the upper or pressure control chamber c. lla'ch of the partitions is formed with a central port 10, 10', that in the upper Vpartition 9 being larger in operative area than the port of the lower partition 9. A self closing valve member 11 is mounted within the chamber and is )rovided with spaced ` valves 12 and 13 whidh correspond and coact 'with the respective ports 10 and 10 just referred to. The valve member ll'has an extension stem at its lower end, designated 14, which coacts withV an apertured guide or bridge 15 formed across the inletof the casing 1. The valve member isfurther provided with an upper extension 16 which coacts with the projecting portion of the bushing 7 so as to guide the valve member 11 in its operation as hereinafter set forth.

A by-pass 17 at one side of the valve casing establishes communication between the entrance chamber a and the pressure control chamber c, this passage preferably having inserted in the upper end thereof a plug 18 which is flattened at one side as indicated at 18, see Figure 3,V for the purpose oit' con stricting the passage to the desired extent. This is the simplest method of forming the passage having sufficient capacity for supc plying pressure to the pressure chamber where pressure in the main pressure line is likely to Vvary in different localities. The plug 18 may ofcourse be flattened to a greater or less extent and in this way the operative area of this by-pass may be simply regulated. A ,n

It will be noted that the central or primary chamber Z9 of the casing is provided withY the outlet port 19 with which is connected the service line for the appliance with which the device is designed` to cooperate. n

Passing now to the description of the means for relieving pressure which is built up in the chamber c, I plrovide a special relief valve which is attac ed to the valve casing in the bore of the bushing 7. This valve device comprises the nipple 20 threat ed at its lower end as indicated at 20 and formed intermediate its length with the hexagonal Wrench hold 22. The upper portion oi' this nipple or body is provided with a series of openings 23 which will place `the chamber c in communication with atmosphere whlen T 1e lower end of the nipple is formedwith a ground valveseat24 with which the depressible valve 25 coacts in the operation of the device.

The upper end of the Valve stem 26 for the valve 25 is threaded to receive the correspondingly threaded cap 27 and a jam nut 29 therefor. A spring 28 is mounted in the bore of the nipple 20 and the lower end of said spring is engaged in the opening 31. At its upper end the spring coacts with the face of a lug 32 of the cap 27. An important feature of this arrangement lies in the manner in which thesprilig 28 coacts with the nipple 2() and the cap 27 which requires that the cap 27 be rotated in order to effect an unseating of the valve 25, In carrying out this phase of the construction the upper end of thenipple is cut out so as to forni a cam surface 30 terminating in the shoulder 80. i

The lug 32 of the cap 27 is designed to ride upon the cam surface 30 and to coact with the shoulder 30 in one of the limits of its movement and also with the shoulder 30" in the other of its limits of movement. The shoulder 32 of the cap' 27 is maintained at the upper extremity of the cam and hence the valve stem cannot be depressed to unseat the valve until the cap 27 is rotated and the lug or projection 32 rides downwardly of the cam `surface 30. As soon as the cap member is released, the spring which has been placed under tension by the operation aforesaid rotates the cap in the opposite direction and incident thereto raises the valve to itsA closed position. This arrangement is designed to prevent too easy an operation ot the valve member such as would be present in a construction requiring merely the depression of the valve without a rotative movement. `Accidental, operation' of the valve is thus eliminated to a great extent aloneknowing the method of its operation.

-though the valve is very easily actuated by As a matter of convenience in manufacture, I have illustrated a modified form of valve member, depicted in Figure 8, wherein a passage is bored centrally entirely through the valve member as indicated at 34. This passage eliminates the necessity or' the by-pass 17 and instead of using the latter by-pass the valve passage may be employed with equal effectiveness.

In operation, assuming that the device is incorporated in the pressure line leading to a stove as depicted in Figure 1, the burner valve is opened and the relief valve 25 is depressed, which immediately opens the pressure chamber o to atmosphere allowing the pressure which has accumulated inthis chamber through the supply of gas passing by the byspass 17 thereto to escape, the gas from the chamber passing out through the openings 23 in the nipple. This relievesthe pressure Yfrom the upper valve 13 and the pressure in ythe entrance chamber a immediately acts upon the valve 12 to elevate the valve member, whereupon the gas will pass. through the chamber b and out the outlet I 19 to t-he burner.

The valve member 11 is actually suspended by the flowing gas pressure which continues and is held in this position because the pressure is equalized on the opposite side of the upper valve 13 which is simultaneously opened with the valve 12. Then the valve is in this position the burners are in use and as soon as these are closed the reduction of the flow through the valve chamber permits the valvev to automatically close. This prevents any accidental escape of gas by opening a burner without lighting the same and in the subsequent use of the stove the burner is opened and the relief valve actuated to secure a supply of gas. While the invention is specifically applied as asafety device for a burner, still it also acts as a cut off for the main supply in the event that the pressure thereof fails so that there is not sufficient to supply the burner. Y

Should it happen that during the operation of the gas supply the pressure in the pressure line falls below a predetermined limit, the valve member 11 would gravitate to its seated position, closing the inlet and shutting off automatically the supply line to the stove. When the pressure subsequentlyrises or increases, the gas passes through the by-pass 17 into the pressure control chamber o where it acts upon the upper valve 13 and, by virtue of the greater operative area of this valve this gas pressure holds the valve member 11 in its seated position. No gas can therefore pass through the safety appliance under the conditions until the built up pressure in the chamber u is relieved. VTo relieve such pressure and -again render the gas supply to the burner operative it is only necessary as before described to slightly rotate the cap 27 of the relief valve and depress the valve 25 which allows the escape of the gas from the chamber c to atmosphere. Immediately an unbalanced condition is created and the pressure upwardly on the lower valve 12 effects an unseating of the valve member and the supply of gas is again operative.

1t will be apparent from the foregoing that a simple arrangement is thus provided without catches and other minor structural parts whichwould be likely to become disordered in use and render the appliance ineffective for safety purposes. 1t should be understood, however, that slight changes may be made in the details of construction and arrangement of the parts without departing from the spirit of the invention and within the scope of the claims appended hereto.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. An automatic gas cut-off of the class described comprising a casing having a gas inlet and outlet, a chamber between said inlet and outlet, a self closing valve member freely movable mounted iii-said chamber controlling the inlet and adapted to be unseated by the gas pressure acting thereagainst in one direction and supported by the flow of gas therethrough, and means whereby the pressure is caused to be exerted against the valve member in the opposite direction to hold the valve member closed 'upon resumption of the gas pressure.

2. An automatic gas cut-off of the class described comprising a casing having an inlet and an outlet, a primary chamber between the inlet and outlet and a secondary lchamber communicating therewith, each having a y gas port, a valve member having a valve for each port, said member being freely openable and held open by the flowing gas pressure passing into and through said primary chamber and adapted to assume closed position upon the cessation of fiow, and means for constantly by-passing said gas pressure to the secondary chamber when the valve is closed to buildup a pressure in the latter for holding the valve member in such closed position.

3. An automatic gas cut-off of the class described comprising a casing having an inlet and an outlet, a primary chamber between the inlet and outlet and a secondary chamber communicating therewith, each having a gas port, a gravity valve member having a valve for each port, said member being freely openable and held open by the flowing gas pressure passing into and through said primary chamber and adapted to assume closed position upon the cessation of flow, means for constantly by-passing said gas pressure to the secondary chamber when the valve is closed to `build up a pressure in the latter for holding the valve member in such closed position", and means for releasing the pressure in the secondary chamber to thereby render the valve member` operable. v

L1. An automatic gas cut-off of the class described comprising a casing having an inlet and an outlet, a primary chamber intermediate the inlet and outlet and a secondary chamber communicating therewith, lsaid chambers having gas ports of different operative areas, a freely movable valve member having disk valves of different diameter for the respective ports and adapted to be unseated by the gas flow entering the casing and to seat by gravity, and a b-y-pass constantly communicating with the secondary chamber to establish a balanced pressure upon the opposite faces of the upper valve member when open.

5. An automatic gas cut-off of tli'e class described comprising a casing having an inlet and an outlet, a primary chamber between the inlet and outlet and a secondary chamber communicating therewith, said chambers having gas ports of dierent operative areas, i'reely movable valve member having a disk valve for each port adapt-ed to be unseated by the gas pressure entering the casing, and to close by gravity alone when the pressure drops below a predetermined limit, a by-pass constantly communicating with the secondary chamber into which chamber gas is supplied upon resumption of the low whereby to create an overbalanced` pressure operable upon the valve'of greater area to maintain the valve member in closed position, a closure for the secondary cham* ber having means to guide said valve, and a manual relief valve upon the closure or said secondary chamber for releasing said overbalancing pressure.

6. An automatic gas cutoff of the class described comprising a casing having an inlet and an outlet, spaced partitions dividing the casing into upper and lower chambers, a port of different area in each partition, a valve member movable free of tension and having spaced valves of diiferent operative areas for said ports, a by-pass in constant communication with the upper chamber to normally support the valve member by a flowing pressure when open and also establish a holding pressure thereon when closed incident to thereduction of flowing pressure, and means for releasing the pressure in said upper chamber whereby to render the valve operative.

7. An automatic cut-oil of the class described comprising a casing, a main. chamber through which the gas ispassed to service, an inlet port thereor, a pressure control chamber, a port establishing communication between said chambers, said port being of larger area than the inlet port aforesaid, a double valve member having disk valves co acting with the said ports, means establishing communication between thefupper face of the valve within the pressureV 'contro-l chamber and the pressure supply, and manually operable means for at will releasing the pressure in said last named chamber.

8. An automatic gas cut-olf or' the class described comprising a casing provided with a seat, a pressure control chamber in said casing having a valve seat of greater area, a self closing valve mounted in said casing and comprising spaced disks of different diameters connected by a reduced stem to constantly expose the opposite faces of the disks, and a release valve for said pressure control chamber including a passage leading to atmosphere and a depressible valve oontrolling said passage. y

9. An automatic gas cut-oli1 of the class described comprising a casing, a pressure control chamber in said casing, a self closing valve mounted in said casing, an inlet chamber communicating with the control chamber through a by-pass port, and a plug for said port having a channel for the pas-` sage of gas therethrough. y

l0. An automatic gas cut-olf of the class described comprising a casing, a pressure control chamber in said casing, a self closing valve mounted in said casing, and a release valve for said pressure control chamber including a passage leading to atmosphere and a valve for said passage including a stem projecting from the casing and actuating means for imparting rotation to said stem to permit of depressing the same.

l1. An automatic gas Vcut-.off of the class described comprising a casing, a pressure control chamber in said casing, a. self closing valve mounted in said casing, and a release valve for said pressure controlling chamber comprising a nipple having a valve seat at the lower end thereof, a valve coacting with said seat having `a stem projectin through the nipple, a cap connected to sai stem and means for preventing movement unseating the valve until said cap member is rotated. y

12. An automatic gas cut-olf of the class described comprising a casing, a pressure control chamber in said casing, a self closing valve mounted in said casing, a release valve for said pressure controlling chamber comprising a nipple having a valve seat at the lower end thereof,` avalve coacting with saidseat having a stem projecting through ythe nipple, a cap connected to said stern,

means for preventing movement yunseatin the valve until said cap member is rotate and a spring for holding the valve seated and coacting with the cap to restore the valve member to seated position after rotation thereof in the unseating action.

In testimony whereof I afiix my signature.

T HoMAs H. BOYD.

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