US2578529A - Fire extinguisher - Google Patents

Description

Dec. 11, 1951 G. E. FERGUSON ETAL 2,578,529

\ FIRE EXTINGUISHER Filed Sept. 19, 1947 s Sheets-Sheet 1 FIG! Z1 oooooo z DOOOOOO/ 1 gal-m 2 oo o J 1 2 INVENTORS GEORGE E/i-Rsusmv fiREDER/G'KA.DDDELIN ATTZYHNEY Dec. 11, G E FERGUSON TA 2,578,529

FIRE EXTINGUISHER Filed Sept. 19, 1947 IS Sheets-Sheet 2 IN mv TOR5 EEURE'E E fsnsusalv T/PEDERIGKAHDUDELIN ATTUENE 1951 s. E. FERGUSON ETAL 2,578,529

FIRE EXTINGUISHER 3 Sheets-Sheet 3 Filed Sept. 19, 1947 W M W m A U .K T f. T M A 5 C E 5;

Patented Dec. 11, 1951 UNITED STATES PATENT OFFICE FIRE EXTINGUISHER Application September 19, 1947, Serial No. 775,028

16 Claims.

This invention relates to fire extinguishers and more particularly to small extinguishers of the hand operated pump type provided with a reciprocating piston for discharging the fire extinguishing contents of the device. The present application is a continuation-in-part of our pending application, Serial No. 703,354, filed October 15, 1946.

While fire extinguishers of the character indicated, as heretofore constructed, have given an excellent record of performance when the extinguishers are properly maintained, improper maintenance results in an inoperative extinguisher. On such occasions when an emergency arises, which requires the use of the fire extinguisher, it is impossible to operate it due to the serious corrosion of the working parts. In most cases this inoperative condition is due to the employment of an improper charge of fire extinguishing fluid in refilling the extinguisher aftgenated hydrocarbons, such as carbon tetrachloride base liquids. It is important in the use of such liquids that they be free from Water. Sometimes the refill, due to improper manufacture or improper care in storage, will contain a certain amount of water or moisture and this, in the course of time, will bring about corrosion difilculties. The water within the fire extinguisher, either in liquid or vapor form, tends to hydrolyze the fire extinguishing fluid and, in the case of carbon tetrachloride, serves to produce and release hydrochloric acid. This acid will attack brass or bronze and other metals of which the fire extinguishers are ordinarily constructed and will bring about corrosion, which will result either in the rupturing of certain parts of the device, when an attempt is made to use it, or in the sticking of parts, which will prevent use of the device.

Even in instances in which the original, proper charge of fire extinguishing fluid is still present in the device, corrosion difficulties have occurred and these have been particularly diflicult to overcome. In the manufacture of fire extinguishers of the character mentioned, each extinguisher is normally subjected to test to determine its tightness against leakage, Many extinguisers which pass this test prove to be satisfactory over long periods of time, while others, which appear to be equally satisfactory in the course of the test, become corroded in some way over a period of time. This occurs even though they may contain the original charge which was free of water at the time it was introduced. Accordingly, an extinguisher which may never have been used over a long period of time, but which is suddenly required for use, may prove to be substantially inoperative with the result that all fire extinguishers of this general character are then condemned by those who encounter these experiences.

Apparently the corrosion difllculties in the situation just mentioned arise from the fact that in the course of time certain extinguishers undergo a sort of breathing action due to repeated changes in atmospheric conditions, such as temperature, barometric pressure, and humidity. There are a number of points in a fire extinguisher where parts which must have relative movement, serve to provide communication between the interior and exterior of the device, unless proper seals are provided. It has been found difficult, moreover, to determine whether a seal will remain effective over a long period of time. For example, a cork seal is sometimes effective for a long time but an occasional cork seal is subject to attack by the vapors given off by carbon tetrachloride and will deteriorate in a comparatively short time. Two sections of cork cut from the same piece are sometimes found to react differently to such vapors. Attempts have been made to overcome this difiiculty by enclosing a cork gasket or washer in lead foil, or by otherwise covering the cork with lead. However, even gaskets of this short have been found to lose their effectiveness over a period of time due to the attack on the cork within the lead covering by the hydrochloric acid gas developed within the extinguisher. In the course of time the breathing action, which is permitted by the failure of one or more of the seals of the extinguishers, will result in the introduction of a substantial amount of moisture into the charge and the same corrosive action will result as in the case of water initially present in the charge. Once the hydrochloric acid gas is developed, this attacks the lead foil around the cork seal, thus destroying the seal and permitting further moisture to enter the extinguisher from the atmosphere.

It has been a primary object of the present invention to eliminate, so far as possible, all corrosion inducing factors of fire extinguishers as heretofore constructed and to thus provide a structure which will be ready for use at all times regardless of the length of time which has elapsed since the extinguisher was last inspected and found to be in good working order. Various expedients have been tried or recommended heretofore for the foregoing purpose, but, for one reason or another, these prior attempts to overcome the corrosion difficulty have not proved successful. In some instances they have been partially effective and have increased the useful life of an extinguisher, but in the long run, some extinguishers have been found to fail in time of need.

In accordance with the present invention the life of a fire extinguisher may be increased almost indefinitely in so far as deterioration from the corrosive action of the charge is concerned. It has been found necessary in achieving this end to employ a combination of features, all of which interact and contribute toward the attainment of the common end. None of the features per se, when employed independently of the others, serve to achieve the desired result, although certain of the features, when used separately or as a part of the entire combination, will produce results greatly superior to any heretofore at tained.

Two features employed in combination have been found important to the full success of the invention. These are: (1) the provision within the extinguisher of a solid substance which is constantly effective to remove water from the vapors and preferably from both the liquid and the vapor content of the chamber and which is, at the same time, effective to neutralize any free acid, and (2) the provision of thoroughly effective sealing means resistant to the action of the liquid and vapor content of the extinguisher as well as to the moisture or other constituents of the outside atmosphere, these sealing mean being provided at all points where relative movement takes place between parts accessible to both the interior and the exterior of the extinguisher. A further specific feature of the invention is the formation of the various sealing means above mentioned of a material which is not merely resistant to the vapors released from the charge but which has an advantageous slight tendency to swell and thus become even more effective as a seal after reaction with the vapors than before.

Other objects, features, and advantages of the invention will appear from a detailed description of an illustrative embodiment of the same, which will now be given in conjunction with the accompanying drawings, in which:

Figure 1 is a longitudinal axial section through a fire extinguisher embodying the present invention;

Figure 2 is a transverse sectional view taken along the line 2-4 of Figure 1;

Figure 3 is a transverse section through a part of the pump system and is taken along the line 3-3 of Figure 1;

Figure 4 is a detail view of a portion of the top closure member forthe extinguisher;

Figure 5 is a longitudinal axial section through a modified form of extinguisher embodying the invention;

Figure 6 is a transverse sectional view through the modified extinguisher, taken along the line 6'6 of Figure 5;

Figure 7 is an enlarged detail view in axial section through the upper portion of an extinguisher of either of the types illustrated in Figures 1 and 5;

Figure 8 is a detail view showing in elevation, a modified form of basket mounted on the upper valve unit;

Figure 9 is a plan view of the device shown in Figure 8, but with the cover member removed;

Figure 10 is a detail view of a bag of desiccating and neutralizing material used in the device of Figures 8 and 9;

Figure 11 is a plan view of a stamping from which the main part of the Figure 8 basket is formed; and

Figure 12 is a detail view of a portion of the top of the basket of Figure 8.

Turning now to the drawings, and particularly Figures 1 to 4 and 7, the fire extinguisher illustrated is in general of a type heretofore produced. It comprises an outer body It), formed of brass or the like, having a cap or closure member II at one end provided with a flange [2 adapted to fit over the end of the body. The construction is rendered airtight at this point by any suitable means as by brazing cr soldering the cap and main body together. At the lower end of the body there is provided a discharge nozzle or nipple l3 which is incorporated in any suitable way in the bottom wall of the body so as to form an airtight juncture. Fitted into the nozzle i3 and forming a close fit therewith is a discharge tube It of relatively small diameter, this tube being secured by solder or the like and extending upwardly along the axis of the body to a point above the cover member II, as indicated at 15. Surrounding the tube It and spaced slightly therefrom, to provide an annular channel around the tube 14 is a piston tube Iii which carrie adjacent its lower end a piston 17. Below the piston 11 the tube I6 is provided with a cap l8 having screw-threaded engagement with the lower end of the tube. In the operation of the piston tube, in the manner to be explained, the cap l8 slides along the tube l4 and forms a reasonably efi'ective seal in relation thereto. The first part of the upward movement of tube I6 is idle, until the cap l8 strikes the underside of the piston, and then the piston and tube travel together.

Toward its upper end the piston tube is provided with a small internal annular shoulder I9 beyond which the wall thickness of the tube is slightly reduced. A handle member 23 fits relatively tightly over the upper end of the tube Ii and is secured to the latter in any suitable way. As shown, this connection may comprise a screwthreaded member 2| having threaded engagement with the upper end of the tube and having an annular recess adapted to receive a tapered pin 22 which may be driven into a suitable opening extending through the flat upper portion of the handle.

A spring 23 is mounted within the top portion of the tube I6 and bears at its upper end against a sealing member 24 which is thus forced against the bottom of the member 21. Sealing member 24 is preferably provided with a small downwardly extending flange formed by a frusto-conical depression in the bottom of the sealing member. This arrangement is such that the pressure imparted to the member 24 by the spring 23 has a component acting outwardly upon the flanged portion of the member and thus squeezes this against the inner wall of the tube IE to provide an exceptionally tight seal.

Member 24 may be formed of any suitable material which is not subject to attack or deterioration by moisture or other constituents of the normal atmosphere, or by the fire extinguishing fluid or vapors therefrom, or gases developed within the fire extinguisher as a result of hydrolysis, corrosion, and the like. It must have suitable compressibility, elasticity, and softness, or plasticity, to enable it to conform readily to the slight irregularity of the metal surface which it engages and at the same time to return to subwhich has been added suitable amounts of the other substances mentioned. As a filler there may be added, for example, equal amounts of carbon black and wood flour, these combined being present to the extent of about 6% of the mixture. Any appropriate substances may be added as plasticizers and stabilizers, the character of these being such that they will not react with the carbon tetrachloride or other polychlorinated hydrocarbon forming the fire extinguishing charge. The stabilizer may also assist in rendering the vinyl resin resistant to reaction with the charge. A specific composition suitable for the purpose is that available under the trade name and designation Tygon 528-1.

At its opposite end the spring 23 acts against a thimble or cartridge or cup-like member 26 slidable Within the tube Hi. When the handle is retracted the spring 23 serves to slide the cup 26 within the tube until the lower lip of the cup strikes the shoulder l9. However, when the handle is locked in its depressed position, shown in Figure 7. the spring 23 is compressed somewhat and the cup 25 is held spaced a short distance from the shoulder l3. Cup 26 has a base 21 against which the spring 23 acts and within its interior the cup carries a small disc or cylinder 23 of a suitable sealing material, preferably of the same type as the member 24. When the handle is locked, this sealing disc is forced by the action of the spring 23 against the free upper end of the discharge tube l4, which passes through the lower open end of the cup, thus effecting a tight seal at this point against the introduction of air through the nozzle l3 and tube I4 into the interior of the extinguisher.

The lower end of the handle is expanded somewhat to form a socket having at its extreme lower end a pair of laterally extending projections 29 adapted to provide a bayonet connection between the handle and a lock plate or retainer 30 secured to the upper end of the body Of the extinguishers. The lock plate has a pair of inwardly extending arcuate flanges 3| adapted to cooperate with the projections 29, the arrangement being such that as the handle is pressed inwardly and the projections are passed between the ends of the flanges and the handle is then rotated, the projections 29 and flanges 3| will have a slight camming action tending to draw the handle inwardly against the lock plate and will then lock the parts in this position. A bushing 32 is provided with flanges which cooperate with the lock plate 30 and the edge of an opening in the top H of the body to clamp these parts together in airtight relation. The bushing also provides a bearing for the reciprocatory movements of the piston tube I6.

Within the lower sleeve-like extension of the handle 20 there is mounted. for axial movement therein, a member 33 having a sleeve portion fitting snugly between the inner surface of the handle and the outer surface of the tube It and having a cupped lower end providing a laterally extending portion 34 adapted to cooperate with a shoulder 35 on the handle. Within the cupped lower end of the member 33 there is held a washer or gasket 36 preferably formed of the same type of material as the sealing element 24. This washer is arranged to be squeezed between the inner surface of the radially extending part 34 of member 33 and the upper end 31 of the bushing 32. The gasket and the bushing preferably have the configuration indicated in Figure '7, i. e., the end of the bushing has a frustoconical depression. As will be seen, the gasket is then not only squeezed firmly against the end of the bushing but is also forced inwardly by the frusto-conical surface against the outer surface of the tube l6. This effects a tight seal around the tube. Squeezing of the gasket 36 is initially brought about by a spring 38 acting between a shoulder within the handle 20 and the upper end of the member 33. As the handle is driven home and locked by the plate 30 the camming action of the projections 29 and flanges 3| serves to impart an extra squeeze to the gasket. When the handle is released the spring 38 serves to urge the member 33 outwardly or downwardly and as the handle is re-engaged the sleeve is forced back into the handle and compresses the spring 38 until shoulders 34 and 35 are brought into solid engagement. At the lower end of sleeve 32 a further sealing means 33 is preferably provided around the tube l6. This may be of any suitable form, such as packing material or a washer or gasket of any appropriate material. A ring 40 surrounding the tube It at the inner end of the sleeve 32 serves to retain the sealing means in the pocket or stuifing box provided for it at the inner end of the sleeve.

Within the body I0 there is also provided a pump cylinder 4| in which the piston i1 slides and which has at each end a valve fitting 42.

These fittings may be of identical construction,

but as shown are provided in inverted relationship. A reduced portion 43 of the upper fitting serves to provide a bearing for the tube It. A stripper member may be provided adjacent this reduced neck portion of the upper fitting and may serve to retain a suitable packing material 44 as shown in Figure '7. The corresponding valve fitting at the lower end of the extinguisher may suitably have merely a bushing 46 fitted within the neck 43 and adapted to provide a relatively tight bearing fit with the discharge tube l4. The outer end of the bushing 46 may be flanged as indicated at 41 to form a thrust bearing in relation to the inner face of the nozzle l3.

Each of the fittings 42 has a lateral extension 43 into which is fitted an auxiliary tube 49 of substantially smaller diameter than the tube 4|. The tube 49 serves to connect the two valve fittings to provide a double acting pump capable of operating regardless of the angle at which the extinguisher is held. An inlet 50 is provided in the extension 48 and this opens into a small chamber 5| in axial alinement with the tube 49. A ball valve 52, however, is adapted to close the passage between the chamber 5| and a chamber 53 with which the tube 43 directly communicates. When the parts are held in the position indicated in Figure l, the ball 52 closes the passage 9 1y float on the surface of the charge. The lime present in the pellets will react with any acid produced within the extinguisher and will thus maintain a neutral condition. In lieu of calcium sulfate there may be used anhydrous cupric sulfate, calcium chloride, or other substances capable of combining with the water in the system and thus removing it from possible reaction with the charge. In lieu of the lime, which forms calcium hydroxide in the presence of water, there may be used any of a number of other alkaline substances, such as calcium carbonate or magnesium oxide or carbonate; so also, a mixture of any of these substances may be used. The amount of lime or other alkaline substance or mixture present in the purifying agent may be quite small. It need not be more than about 25% of the entire mixture, although a somewhat greater amount may be provided if desired. Calcium chloride as com iercially available normally contains a sufficient amount of lime and other alkaline substances to be suitable for the formation of the pellets or granules of the present invention, without the addition of other alkaline substances. A small amount of activated carbon may also be added advantageously to the desiceating agent. This will serve to adsorb certain corrosive impurities which are sometimes present in the liquid in small amounts. The activated carbon may suitably form between 1 and 5% of the purifying mixture, by weight.

In order to retain the purifying agent in such a way that it will not interfere with the operation of the pump system and at the same time will be accessible for purifying both the liquid and vapor space within the body, a foraminous basket 62 has been provided, this basket being mounted upon the upper valve fitting 42. The top of the basket may simply be provided with an opening large enough to fit over the neck 43 of the valve fitting. The bottom of the basket, however, must have a larger opening adapted to fit over the two chambers 55 and 5| of the valve unit. So, also, the cylindrical wall of the basket must be cut away in the region of the chamber 5| to permit the basket to be passed over and around the inlet opening 5|! of the valve unit. While the basket is preferably formed of a perforated metal sheet, formed of brass or the like, and is preferably tin-coated, it may be formed of other materials and in other ways. It may, for example, be a wire basket formed of tin-coated copper wire, or of stainless steel, or the like.

In the normal use of the extinguisher the liquid charge, which is introduced through the opening provided in the cap ll upon the removal of a plug 63 (Figure 4), will fill the extinguisher to a level about half the depth of the basket 62. Plug 63 is sealed by a washer 63a, formed of any suitable material such as the vinyl resin composition hereinabove mentioned. It will be understood that the extinguisher, when not in use, is normally supported by a bracket or the like in the position indicated in Figure 1, so that a part of the basket will be immersed in the liquid charge and a part will be exposed to the vapors in the space above the liquid. As will be seen, the construction and arrangement of the basket 62 is such that it will not interfere in any way with the operation of the extinguisher. It will permit the free movement of the pump parts, including the gravitational adjustment of the parts in accordance with any movements of the body of the extinguisher about its axis when held horizontally. Furthermore, the purifying agent and also the reaction products will, at all times, remain in the basket 62 and will not interfere with the operation of the system. A single charge of the purifying agent, provided in the basket 62, will last indefinitely in the normal use of the fire extinguisher. However, in the event that an extinguisher is subjected to abnormally hard usage, the contents of the basket 62 may be emptied and replenished upon the removal of the top closure II of the body of the extinguisher. The location of the basket is such that whenever a fresh charge of extinguishing fluid is introduced into the body through the opening closed by the plug 63, the charge will pass through the basket and will thus be subjected to a filtering or purifying action.

Referring now to Figures 5 and 6, there is shown a modified arrangement for retaining the purifying agent. In general, the extinguisher of this modified construct on may be the same as that of Figures 1 to 3. However, the purifying agent, in lieu of being contained in a foraminous basket, is simply in the form of a stick 64 which is retained by a spring member 65 having a plurality of resilient clamping fingers 66 secured thereto, by which the spring retainer may be mounted upon the cylinder 4| of the pump mech anism. Spring 65 and fingers 66 are preferably formed of stainless steel. This arrangement is again such that a part of the stick will normally be immersed in the fire extinguishing liquid, while another part will project into the vapor space above the liquid. The stick 64 may be formed of the same substance or mixture of substances as the granules, pellets, or lumps used in the basket of Figure 1. To lend support to the material as it reacts with the water or acid within the extinguisher it may be compressed around a suitable core, such as a stainless steel wire.

If desired, both the foraminous basket and the stick might be employed in order to insure the presence of a part of the purifying agent within the liquid and a part within the vapor space, regardless of the position in which the fire extinguisher is kept when not in use. Thus, if the extinguisher were kept in a horizontal position while not in use, the stick 64 might be largely, if not entirely, in the vapor space of the extinguisher, but a portion of the foraminous basket would, in that case, be immersed in the liquid.

Referring now to Figures 8 to 12, inclusive, there is shown a modified form of basket which may be used in lieu of the basket 62 of Figure 1. It has the advantage of simplicity of manufacture and assembly and in conjunction with a further feature, also to be described, facilitates the introduction of the desiccating and neutralizing agent. The modified form of basket comprises a sheet metal stamping 61 formed preferably of brass. It may be of relatively light-weight and stamped. for example, from a B 8: S 24 gauge sheet. The stamping comprises a substantially circular central portion 68 and a plurality of radial extensions 69, each provided with an elongated slot Ill. The stamping is first formed flat, as shown in Figure 11, and the extensions 69 are then bent upwardly to form the wall of the basket, as indicated in Figure 8. Access to the interior of the basket isprovided by the slots 70 and also by the spaces ll provided between the bent-up extensions 69. The central circular portion 68. forming the base of the basket, is provided with a large central opening 12 having a slot 13 at one side extending to the periphery of the part 58.

This enables the assembly of the basket upon the upper valve unit in the manner above described in relation to the basket 62. The top of the basket is preferably closed by a cup-shaped member 14 stamped or drawn from a flat perforated sheet of suitable material, such as brass. The flange or rim of the top 14 is adapted to fit snugly over the upper ends of the extensions 69 to retain the basket in assembled relation. A spring washer 15 (Figure 12) may be provided above the cap, this washer, formed preferably of brass having tongues arranged to cooperate with the sleeve portion 43 of the upper valve housing to hold the basket in assembled relation on the valve unit.

The desiccating and neutralizing agent may be provided in the basket in any of the forms hereinabove explained, provided the individual particles of the agent are sufilciently large not to be able to pass through the openings 10 and H of the wall of the basket. If desired, the desiccating and neutralizing agent may be in the form of a single solid cake of an appropriate shape to snugly fit within the space available in the basket. Such a cake may be formed by melting the agent and pouring it into an appropriate mold, or the agent in a powdered form may be moistened just sufiiciently to enable it to be compressed into a cake of the desired shape and retained in such shape.

In the preferred practice of the invention, however, particularly when the basket of Figures 8 to l is employed, the desiccating and neutralizing agent in powdered or granular form is retained within a bag 16 (Figure 10) formed of any suitable material. A muslin bag formed of a relatively thin muslin having a 48 count has been found highly satisfactory for the purpose. The fire extinguishing fluid, such as carbon tetrachloride and the vapors developed within the extinguisher, will not attack the muslin so that the bag will retain its original strength over a substantial period of time. Bags formed of other materials, of either cellulosic base or other substances, may be used in lieu of the muslin bag. It is important merely that the material of which the bag is formed shall not be subject to attack by the vapor and liquid content of the extin guisher and it should have the necessary strength to enable it to be handled and suitably packed within the foraminous basket. So, also, the weave of the material selected may vary somewhat depending upon the fineness of the desiccating agent which it must retain. It should not, however, be of such a tight weave that it will interfere substantially with the free passage of liquid and vapors to the interior of the bag. The bag-forming material may suitably be first formed into a long slender tube and the ends of the latter may then be stitched together, as shown in Figure 10, the last end being stitched after the bag is filled.

In making use of ordinary unbleached muslin for the production of the bag I6, it has been found desirable to remove the usual fillers and starch from the material to avoid the danger of having the fine particles of these substances interfere with the proper operation of the parts within the extinguisher. Also, it has been found desirable, though not essential, to impregnate the bag material with a suitable wetting agent so as to facilitate and speed up the passage of the liquid and vapors through the walls of the bag into contact with the desiccant within it. Among the suitable wetting agents for this purpose, which are not subject to attack by the fire extinguishing liquid, may be mentioned decyl benzene sodium sulfonate such as sold under the trade name Santomerse D, sodium sulfonate of petroleum hydrocarbons having H3 or more atoms of carbon to the hydrocarbon molecule such as sold under the trade name Ultrawet 30E, and a sodium salt of sulfonated octyl and lauryl alcohols such as sold under the trade name TLF-199.

In the use of the bag l6 it will be understood that it is appropriately bent to fit within the basket. The ends of the bag are positioned at opposite sides of the opening 13 through which a portion of the valve unit extends into the interior of the basket.

While certain illustrative embodiments of the invention have been disclosed in considerable detail, it will be understood that numerous changes may be made in the construction, arrangement, and operation of the various parts without departing from the general principles and scope of the invention. Some of the advantages of the invention may be derived throughthe use of an enlarged cap or plug arranged to provide an extension of the vapor space of the container. For example, the filler plug 63 may be replaced by an elongated hollow cap or plug adapted to retain, in any of the forms hereinabove described, a suitable desiccating and neutralizing agent. The cap or plug, it will be understood, is open at its inner end and is in free communication with the vapor space of the container. A screen or other suitable member may be provided at the inner end of the plug to retain the desiccant. The outer end of the cap or plug may be either permanently closed or may be provided with a removable closure. In the latter event filling of the extinguisher with a new fire extinguishing charge may take place through the elongated cap or plug. so that the contents of the latter may filter the charge as it is introduced. The desiccating agent may also be readily replaced upon the removal of such an end closure. Other forms of purifying agent having the characteristics above specified may be employed. So also, other materials having the required properties may be utilized in the formation of the various sealing elements hereinabove described. Moreover, while the invention relates particularly to fire extinguishers using carbon tetrachloride, it is applicable also to those charged with other halogenated hydrocarbons, such as bromine or fluorine substitution products. For example, dibrom methane or methyl bromide or monoflor methane may be used.

We we claim is:

l. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said liquid filling said body to a predetermined level with a vapor space above it, means for discharging said liquid, and means for retaining a dehydrating agent in solid form within said body partly below and partly above said liquid level for removing moisture from the liquid and vapors.

2. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said liquid filling said body to a predetermined level with a vapor space above it, means for discharging said liquid, and means for retaining within said body partly below and partly above said liquid level an agent for removing moisture from the liquid and vapors, said agent comprising a solid substance having a reater ai'linity for water than does said halogenated hydrocarbon.

3. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said liquid filling said body to a predetermined level with a vapor space above it, means for discharging said liquid, and means for retaining within said body partly below and partly above said liquid level an agent in solid form for removing moisture from the liquid and vapors, said agent comprising a moisture absorbing solid substance selected from the group consisting of calcium sulfate, anhydrous cupric sulfate and calcium chloride.

4. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said liquid filling said body to a predetermined level with a vapor space above it, means for discharging said liquid, and means for retaining within said body partly below and partly above said liquid level an agent in solid form for removing moisture from the liquid and vapors, said agent comprising a mixture of anhydrous calcium sulfate and lime.

5. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said liquid filling said body to a predetermined level with a vapor space above it, means for discharging said liquid, and means for retaining within said body partly below and partly above said liquid level an agent in solid form for removing moisture from the liquid and vapors, said agent comprising a calcium compound selected from the group consisting of calcium sulfate and calcium chloride.

6. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said liquid filling said body to a predetermined level with a vapor space above it, means for discharging said liquid, and means for retaining within said body partly below and partly above said liquid level an agent in solid form for removing moisture from the liquid and vapors, said agent comprising calcium chloride having intermixed therewith a small amount of lime.

7. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said liquid filling said body to a predetermined level with a vapor space above it, means for discharging said liquid, a perforate container mounted within said body partly below and partly above said liquid level, and an agent in said container for removing moisture from the liquid and vapors, said agent comprising a solid substance selected from the group consisting of calcium sulfate, anhydrous cupric sulfate, and calcium chloride.

8. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said liquid filling said body to a predetermined level with a vapor space above it, means for discharging said liquid, and means for retaining Within said body partly below and partly above said liquid level an agent for removing moisture from the liquid and vapors, said agent comprising a stick formed at least in part of a substance having greater afiinity for water then does said halogenated hydrocarbon.

9. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said liquid filling said body to a predetermined level with a vapor space above it, means for discharging said liquid, said means comprising a pump having a cylinder within said body, and means for retaining within said body partly below and partly above said liquid level an agent for removing moisture from the liquid and vapors, said retaining means comprising a spring like member mounted on said cylinder, and said agent comprising a stick of desiccating material held by the coils of said member.

10. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said liquid filling said body to a predetermined level with a vapor space above it, means for discharging said liquid, said means comprising a pump having a cylinder and a valve unit within said body, and means within said bod disposed partly below and partly above said liquid level for removing moisture from the liquid and vapors. said last recited means comprising a. basket mounted on said valve unit and a solid substance within said basket which has a greater afiinity for water than does said halogenated hydrocarbon.

11. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said liquid filling said body to a predetermined level with a vapor space above it, means for discharging said liquid, said means comprising a pump having a cylinder and a valve unit within said body mounted for free angular movement by gravity about the axis of said body, and means within said body disposed partly below and partly above said liquid level for removing moisture from the liquid and vapors, said last recited means comprising a basket mounted on said valve unit for angular movement therewith and a solid substance within said basket which has a greater aifinity for water than does said halogenated hydrocarbon.

12. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said liquid filling said body to a predetermined level with a vapor space above it, means for discharging said liquid, said means comprising a pump having a cylinder and a valve unit within said body and a piston tube extending through a wall of said body, and means within said body disposed partly below and partly above said liquid level for removing moisture from the liquid and vapors. said last recited means comprising a basket mounted on said valve unit around said piston tube and a solid substance within said basket which has a greater affinity for water than does said halogenated hydrocarbon.

13. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said body having a vapor space above the liquid, a closable opening communicating with said vapor space for enabling the introduction of fire extinguishing liquid into said body, normally sealed means enabling the discharge of the liquid from said body, and means for retaining Within said vapor space an agent for removing moisture from the vapors therein, said agent comprising a solid substance in anhydrous form capable of combining with the moisture to produce a crystalline substance in which the water is held in a form incapable 01' further chemical reaction with the contents of said body.

14. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said body having a vapor space above the liquid, a closable opening communicating with said vapor space for enabling the introduction of fire extinguishing liquid into said body, normally sealed means enabling the discharge of the liquid from said body, and means for retaining within said vapor space an agent for removing moisture from the vapors therein, said agent comprising a solid substance in anhydrous form capable of combining with the moisture to produce a crystalline substance in which the water is held in a form incapable of further chemical reaction with the contents of said body, said retaining means serving to retain said substance at least in part in said vapor space.

15, A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said body having a vapor space above the liquid, a closable opening communicating with said vapor space for enabling the introduction of fire extinguishing liquid into said body, normally sealed means enabling the discharge of the liquid from said body, and means within said vapor space for removing moisture irom the vapors therein, said last mentioned means comprising a solid substance in anhydrous form capable of combining with the moisture to produce a crystalline substance in which the water is held in a form incapable of further chem ical reaction with the contents of said body, and 1 means for retaining said substance at least in part in said vapor space, said retaining means including a flexible bag formed of cellulosic filaments adapted to permit the free passage therethrough of vapors but to prevent the escape of particles of said solid substance.

16. A fire extinguisher comprising a closed body containing a halogenated hydrocarbon fire extinguishing liquid, said body having a vapor space above the liquid, normally sealed means enabling the discharge of the liquid Irom said body, and means within said vapor space for removing moisture from the vapors therein, said last mentioned means comprising a receptacle in said vapor space in free communication with the vapors therein, receptacle containing and a flexible bag within said a desiccating agent in granular form, said bag being formed of cellulosic in filaments and being of such texture as to permit the passage of vapors therethrough but to prevent the escape of said agent.

GEORGE ENNIS FERGUSON. FREDERICK A. DODELIN.

REFERENCES CITED The following references are of record in the file of this patent:

20 UNITED STATES PATENTS Number Name Date 1,097,145 Snelling May 19, 1914 1,231,815 Verdone July 3, 1917 1,378,609 Pearsons May 17, 1921 2,116,319 Miller May 3, 1938 2,148,770 Mlttendorf Feb. 28, 193.9 2,204,798 Ferguson June 18. 1940 2,326,861 Huthsing Aug. 1'7, 1942 OTHER REFERENCES Booklet, Vinylite Resins, copyright 1942, by Carbide and Carbon Chemicals Corp... 30 East 42nd st, New York, N. Y. ( pages 6 and 20.)

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