Nov. 21, 1961 P. M. CARTER ET AL FIRE. EXTINGUISHER VALVES 4 Sheets-Sheet 2 Filed D60. 30, 1955 Nov. 21, 1961 P. M. CARTER ET AL FIRE EXTINGUISHER VALVES 4 Sheets-Sheet 3 Filed Dec. 30, 1955 m R 4 mm m w m M f D P. M. CARTER ET AL FIRE EXTINGUISHER VALVES Nov. 21, 1961 4 Sheets-Sheet 4 Filed Dec. 50, 1955 IN VEN TORS Pym; /P A4. U Y DAN/EL NIZPDOZ/I I II w H I Patented Nov. 21, 1961 3,009,681 FIRE EXTINGUISHER VALVES Philip M. Carter, Ossining, N.Y., and Daniel Nardoza, Keyport, N.J., assignors, by mesne assignments, to The Casco Products Corporation, Bridgeport, Conn., a corporation of Connecticut Filed Dec. 30, 1955, Ser. No. 556,719 3 Claims. (Cl. 251-332) This invention relates to valves and more specifically to an improved valve and cooperating seat assembly that is particularly useful as the valving mechanism in the discharge head of pressure type fire extinguishers as well as for other purposes.
In the pressure type fire extinguishers, it is important that the discharge valve afford a completely dependable closure means to prevent the loss of pressure throughout long periods of time and in addition provide an easily operable mechanism so that the fire extinguishing medium can be quickly discharged in time of need. It is also important that the valve reclose with full efficiency after each intermittent partial discharge whether the spacing is at small or great intervals. The attainment of these objectives has not been met satisfactorily by devices heretofore proposed, notwithstanding their complication and expense. Where the extinguishing medium has been dry chemical or powder, the prior valves have been signally defective in preventing leakage after a partial discharge. Moreover, prior known valves, particularly for fire extinguisher use, have been both expensive and difficult to maintain and repair.
Accordingly, an object of the invention is to provide a valve and seat assembly which maintains a tight leakproof joint though under substantial pressure for a prolonged period of time.
Another object is to provide such a valve and seat assembly which recloses effectively, after partial discharge, regardless of the medium discharged.
Another object is to provide such a valve and seat assembly which recloses effectively even though the medium discharged be dry.
Another object of the invention resides in the provision of an improved valve and seat assembly that functions to wipe the valve seat clean in the closing operation.
Still another object is to provide a valve and seat assembly wherein the valve can be seated effectively regardless of the type of pressure employed.
Still another object is to provide such a valve and seat assembly which reacts in response to the pressure of the fluid being retained to provide a complete and permanent seal and prevent loss of pressure.
A further object of the invention resides in the provision of an improved valve and seat assembly that not only insures a good seal but also enables the valve to be opened quickly to a position of full or partial flow.
A further object of the invention is to provide a valve which will be self adjusting and can be repaired and re assembled without any particular skill.
A still further object of the invention is to provide an improved valve particularly useful for powder type fire extinguishers that is designed and constructed to provide for the smooth flow of the fire extinguishing medium past the valve when it is open and to function effectively to wipe the valve seat clean as the valve closes to thereby effect a more perfect seal.
A further general object of the invention is to provide an improved valve and seat assembly for pressure type fire extinguishers and other purposes.
The above and other objects and advantages of the invention will become more apparent from the following description and accompanying drawings forming part of this application.
In the drawings:
FIG. 1 is a side elevational view of a fire extinguisher having a discharge head incorporating a valve and seat assembly in accordance with the invention;
FIG. 2 is a top plan view of the discharge head of FIG. 1;
FIG. 3 is a section taken on line 33 of FIG. 2 showing the valve carried by the head in closed position;
FIG. 4 is a view similar to FIG. 3 but showing the valve in the open position;
FIG. 5 is an exploded perspective view of the valve member per se;
FIGS. 6, 7 and 8 are enlarged cross sectional views of the valve and seat assembly in accordance with the invention showing the valve in different positions of its stroke.
Referring now to the details of the drawings and at the outset to FIGS. 1 to 4 thereof, the discharge head of the fire extinguisher is generally denoted by the numeral 10 and is arranged for suitable attachment to a tank 12 in which the fire extinguishing medium is retained under pressure. In the case of an extinguisher utilizing a powder, employing pressures as low as to p.s.i., welded bottles of the type illustrated are generally approved. When powder, such as sodium bicarbonate, is employed about three-fourths of the tank is usually filled with the powder and after the head 10 is secured in place on the tank, the latter is charged with air, nitrogen or other suitable inert gas to a pressure of about 190 pounds. Since powder normally tends to settle to the bottom of the tank, a tube 1 3 is secured to the head 10 and extends to within close proximity to the tank bottom. The internal diameter of this tube governs the maximum rate at which powder can be discharged from the outlet 14.
The tube 13 can be interchanged with others of different internal diameter to accommodate different tank sizes and rates of discharge. For this purpose the tube 13 is provided with an enlarged screw threaded nipple 15 at one end thereof. This nipple threadably engages with a suitable seat on the discharge head. Hence the discharge head of the invention can be effectively employed with a wide variety of shapes and sizes of tanks 12 and for various rates of discharge merely by coupling the proper tube 13 thereto.
The discharge head 10 comprises six basic elements, namely, the housing 16, the valve and stem assembly 17, the valve operating handle 18, a fixed handle 19, a pressure gauge 20 and the locking device 21. The valve housing 16 has an enlarged lower portion 22 terminating in a downwardly extending tubular part 23 having external threads 24 and internal threads 25. The internal threads 25 are arranged to receive the adapter 15 carrying the discharge tube 13. It is desirable to maintain a reasonably good seal between the adapter 15 and the lower end 23 of the housing 16. Normally the seal provided by interlocking threads is adequate, though a gasket may be employed if desired. The external threads 24 on the portion 22 are for engagement with a corresponding threaded opening in a suitable fitting secured to the top of the tank or bottle 12. The valve housing 16 is seated 1n sealed relation with respect to that fitting by a pair of 9 rings 26 and 27 carried in suitable recesses 26 and 27 in the housing 16. The details of this relationship will be set forth in a companion application by the instant inventors.
The outlet passage 28 of the housing 16, defined in part by the threads 25 on the lower end thereof, extends upwardly into a tapered section 29 which latter serves o receive and cooperate with the improved valve 30 forming part of the valve and stem assembly 17. The tapered wall 29 actually forms the valve seat and will be discussed in greater detail as the description proceeds.
The upper end of the tapered section or seat 29' terminates in a cylindrical section 31 which in turn communicates with a transverse opening 32 having a threaded portion or mouth 33 for attachment of a suitable nozzle generally denoted by the numeral 34 (FIGS. 2 and 3). The nozzle 34 may be in any desired form or it may be coupled to the mouth or exit 33 of the extinguisher by means of a flexible hose. In the case of powder type extinguishers wherein the powder is loaded into the cylinder 12 and then the discharge head 10 is secured to the cylinders as previously described, the mouth 33 is used for the attachment of a gas injection adapter 35' illustrated in cross section in FIG. 1.
The valve operating assembly 17 includes, in addition to the valve head 30, a valve stem 36 extending upwardly through an opening 37 in the valve housing and into an enlarged chamber 38 in the upper end of the body 16. The chamber 38 includes a pair of gaskets 39 and 40 firmly seated in the bottom thereof and snugly receiving the valve stem 36. The upper end of the valve stem 33 is provided with a cylindrical valve operating member 41 threadably secured thereto by means of threads 42 and extending upwardly beyond the top of the housing 16. A spring 43 is disposed between a flange 44 on the valve operating member 41 and bears downwardly against the gaskets 39 and it to secure them in place and seal the opening 37. The spring also acts to move the valve operating mechanism 41 upwardly to urge the periphery of the valve head 30 into contact with the tapered wall of the valve seat 29 to close the valve.
The valve operating member 41 is guided within the chamber 38 by means of an annular cap 45 threaded at 46 to the upper end of the housing 16. The cap is sealed to the end of the housing 16 by means of a gasket 47 and is slidably sealed to the periphery of the valve operating member 41 by means of an ring 48 disposed in a recess formed in the wall of the opening 45 in the cap. This 0 ring serves as a guide for the member 41 and to seal against weather.
The valve 39 in the illustrated embodiment of the invention is in the form of two cones with their large ends opposed and with resilient Washer or ring 30 disposed about a seat at that position. This structure, to be described in detail hereinafter, enables the resilient ring 31'? to effect an initial seal against the tapered opening 29 on upward motion of the valve stem. This motion is, however, limited by contact of the periphery of the upper cone with the tapered side wall 29. As this contact, or engagement, takes pace the ring 30' is deformed not only by the movement of the valve, but also by the pressure of the gas in tank 12 to insure a positive and dependable seal.
The operation of the valve 30 is accomplished by the handles 18 and 19, the latter being a so-called fixed handle pivotally attached at 49 to a lug 50 formed integrally with the valve housing 16. The handle 18 is in the shape of an L with the short leg 51 thereof pivoted at 52 to 2. lug 53 formed as an integral part of the housing 16 and on the side thereof opposite to the lug 59. The longer leg 54 of the handle 18 has a rounded surface 54 which engages the rounded operating surface 4-1 of the valve operating mechanism 41. Hence, when the handle 13 is depressed, the valve assembly 17 and the valve head 30 are moved downwardly against the action of the spring 43 and against the effect of the pressure in the bottle 12 to open the valve and permit the fire extinguisher medium to pass upwardly and outwardly through the exit 33.
In order to prevent the valve from being accidentally operated by depression of the handle 54, a safety locking device 21 is provided. This is in the form of a clip 64 of spring steel, prosphor bronze or other resilient material and having a circular handle 70 attached thereto. The clip 64 is in the shape of a U with the legs 65 and 66 having portions thereof arcuately formed as indicated at 66' and 65 to engage the cylindrical body part of the valve operating member 41. The outer ends 67 and 63 of the clip are bent outwardly to facilitate the insertion of the clip about the valve operating member 41 and between the underside of the handle 18 and the top side of the cap 45 on the body 16. When this clip is in place on the member 41 it bridges the space between the handle 16 and the cap 45 and prevents accidental depression 01 the handle 18 and consequent operation of the valve 30.
As pointed out above, the valve 30 is moved into the closed position by the conjoint action of the spring 43 and the pressure within the tank 12. If desired, added closing force may be applied by manual operation of the handle 18 in an upward direction though that is rarely necessary. Alternatively, of course, the spring 43 can be made strong enough to do the complete closing job. This would, of course, allow for reversing the action of the valve to close it by downward action against a seat reversely tapered or formed with respect to the taper of the seat 29.
The valve 30, in the illustrated embodiment of the invention, as best seen in FIGS. 58, comprises three basic elements, namely an upper cone 80, a lower cone 81 and a flexible ring 30 of rubber, plastic or other suit able material. The upper cone is centrally bored at 82 for slidable reception on the reduced end 83 of the shaft 36. Thus the small end 84 of the cone abuts against the shoulder 85 formed where the reduced end of the shaft commences.
The large end or base of the cone 89 is recessed around its periphery to form one side of a seat for the gasket 30', which seat is bordered by an annular surface 86 inclined upwardly and inwardly with respect to a plane at right angles to the axis of the cone. That surface terminates at its inner end at a cylindrical shoulder 87 coaxial with the cone.
The top plane surface, or base 88 of the lower cone 81 has a bordering annulus 38 opposing the surface 86 and forming the other side of the seat for the gasket 30. The annulus 88 is inclined downwardly with respect to the plane of the base 88. Thus, as the cones 80 and 81 are assembled and tightened up on the end 83 of the shaft 36, the gasket 30" will be forced inward on its seat between the surfaces 86 and 88' and will be strongly held against any forces tending to dislodge it. The volume of the gasket 30' is such that it fills its seat and only a controlled part 30" of it is allowed to extend outwardly therefrom in the form of a rounded nose.
The slopes of the cones 8t) and 81 are preferably the same and the cone 81 holds the assembly together and in place on the stem 36. This is due to its threaded bore 91 which threadedly engages the extension 83 of the shaft 36. The small end of the cone 31 is preferably slotted, or otherwise formed as shown at 92 to receive a tool for applying and removing it. Conveniently also the stem 36 is bored at 93 for the reception of a pin, or other suitable member, so that the stem 36 can be held while the cone 81 is being applied or removed.
For a showing of the manner in which this valve is related to its seat 29 in various positions, reference is made to FIGS. 6, 7 and 8. In FIG. 6 the valve is shown in its open position with a passage between the radiused nose 30" of the gasket 30 and the tapered side 29. The pascage is sufficient for the discharge of the fire extinguishing medium at the rate desired. Furthermore, the opposed conical surfaces of the parts 80 and 81, taken in conjunction with the conical seat 29, direct the flow in a uniform manner, reducing turbulence to a minimum.
On the initial closing step of the valve, as seen in FIG. 7, the nose 30" of the gasket wipes against the seat 29 cutting off the flow of the extinguishing medium, whether liquid or powder, cleans off that seat, and then seats against it to form an initial seal. Once such a seal is effected further sealing is enhanced by the pressure within the container acting below the gasket and deforming it against the seat 29. Thus, a quick cutoff is achieved and a tight closing readily effected once the spring and pressure action Work together.
In the iinal closed position, as seen in FIG. 8, the periphery 90 of annulus 86 has come into contact with the seat 29. This is a metal to metal line contact about a line 94 and it forms as tight a joint as can be achieved by metal to metal contact. Assurance that this joint is completely tight is, of course, achieved by the presence of the extended nose 30" of the gasket 30. This gasket is compressed inwards and deformed downwardly and makes a positive seal against the seat 29. Pressure acts upon it even in the fully closed position, since the seat 29 tapers outwardly in its downward extent, leaving a small space between the periphery 89 of the cone 81 and the seat 29.
Long and effective life of the gasket is assured, however, since it is backed up by the metal of the cone 80 so that there is practically no space over which unsupported gasket material has to withstand the effect of the pressure within the container. The gasketing is in a sense a highly effective packing, but one Which can be removed and reseated as desired.
The recessing of the upper and lower cones 80 and 81 at 86 and 8-8 to receive the gasket enables the gasket to effect its sweeping or wiping action as the valve is closed without danger of its popping out.
The valve structure and action of the invention achieve results which have been out of the question with prior constructions. First the valve positively prevents the possibility of it being held open after a partial discharge, by powder building up and being compacted on the valve seat. This is due partially to the wiping action of the gasket surface 30" as the valve closes, but more positively to the metal line contact between the periphery 90 of the annulus 86 and the surface 29. There is no fiat surface contact on which powder can compact to block the closing action. On the contrary, there is a line or knife-like contact which would cut through any powder or push it aside due to the diverging tapers of the cone 80 and its seat 29. This effective closing action would persist whether the closing were pressure assisted or were merely spring induced as where the valve closed downwardly against a reversely tapered seat.
Secondly, the valve needs no adjusting to make it seat properly. By the nature and relationships of its parts it eliminates any need for adjusting because it is self adjusting. \All that is needed is to make sure that the valve member is turned all the way in on one end of the valve stem and that the valve operating member 41 is turned all the way in on the other end. This establishes the proper relationship between these parts so no adjusting is needed to achieve that relationship.
The valve of the invention is, accordingly, a most effective one for meeting the rigid requirements of fire extinguisher use-positive sealing against relatively high pressures for long periods of time without use, quick and effective opening whenit needs to be used, and effective and positive closing after each use. Nevertheless, the valve is formed for simple assembly and disassembly should it be desired to replace the gasket 30'.
While only one embodiment of the invention has been shown and described, it is understood that changes, modifications and alterations that might suggest themselves to one skilled in the art may be made without departing from the true scope and spirit thereof.
Having described our invention, what we claim as new and desire to secure by Letters Patent is:
1. A valve for a dry powder fire extinguisher comprising -a pair'of frusto conical members positioned in base to base relationship and having axially spaced peripheral edges of substantially the same diameter, a valve stem slidably and axially extending through the upper of said members and threadedly received in the lower of said members and step means toposition the upper of said members on said stem to maintain said members in base to base engaged relationship, and an annular resilient gasketing member secured between said opposed bases and having a portion extending out to a small extent past said opposed peripheral edges.
2. A valve and seat assembly for a dry powder fire extinguisher comprising a tapered conical valve seat converging away from the pressure end thereof, a valve cooperating with said seat and comprising a frusto conical member tapered in the same direction as the taper of said seat but at a greater slope with respect to the axis of said seat than the slope of said seat, the base of said member having a greater diameter than that of the smaller end of said seat whereby a metal to metal line contact can be effected between said base and said seat to limit the closing action of said valve, an annular resilient element seated around the periphery of said frusto conical member on the preessure side of said base and formed for engagement with said seat in addition to said metal to metal line contact when said valve is closed, means for holding said annular element in tight contact with said base, and said annular element normally extending radially outwardly with respect to the periphery of said base and forming pressure responsive means to hold said periphery against said seat and to form a positive seal between said frusto conical member and said seat, said holding means being formed as an additional frusto conical member having a base of substantially the same peripheral diameter as that of said first frusto conical member, said base of said additional frusto conical member overlying substantially all of said resilient element except the valve seat engaging portion thereof.
3. In valve construction for dry powder fire extinguishers, a housing, including a valve and seat assembly, said assembly comprising a tapered conical valve seat converging away from the pressure end thereof, a valve cooperating with said seat and comprising a frusto conical member tapered in the same direction as the taper of said seat but at a greater slope with respect to the axis of said seat than the slope of said seat, the base of said member having a greater diameter than that of the smaller end of said seat whereby a metal to metal line contact can be effected between said base and said seat to limit the closing action of said valve, an annular resilient element seated around the periphery of said frusto conical member on the pressure side of said base and formed for engagement with said seat in addition to said metal to metal line contact when said valve is closed, means for holding said annular element in tight contact with said base, and said annular element normally extending radially outwardly with respect to the periphery of said base and forming pressure responsive means to hold said periphery against said seat and to form a positive seal between said frusto conical member and said seat, an exhaust chamber formed in said housing and being in open communication with the smaller end of said conical valve seat, a valve stem being concentric with respect to said valve, extending through said chamber and engaging said valve concentrically at the end of said frusto conical member opposite the base thereof and being secured to said valve for actuating the same.
(References on following page) References Cited in the file Of this patent UNITED STATES PATENTS Forestier June 18, 1889 Miller July 19, 1898 Boyce Jan. 11, 1921 Hampton July 6, 1929 Wile Aug. 18, 1936 Hoof Mar. 18, 1947 Allin Apr. 13, 1954 Bashark Feb. 1, 1955 55 Rand Mar. 22, 1955 Nurkiewicz Mar. 12, 1957 Hollander Apr. 15, 1958 Mascusi Aug. 5, 1958 Novotny Sept. 15, 1959 FOREIGN PATENTS Australia of 1954 Great Britain Feb. 2, 1955