US2256902A - Fire extinguisher construction - Google Patents

Description

Sept. 23, 1941. c. K. HUTHSING FIRE EXTINGUISHER CONSTRUCTION 2 Sheets-Sheet l l I/ NTO/e Maras /gf w25/Sigg yme. TTORNEYS.

Filed Nov. l'7,- 1958 Sept. 23, 1941. c, K. HUTHSING FIRE EXTINGUISHER CONSTRUCTION Filed NOV. 17, 1938 2 Sheets-Sheet 2 remise sepa 23,1941` UNITED STATES 'PATENTy QFFICE 2.25am rma moments ooNs'mUorroN essere x. antenne', crime reime, men. sesamo@ November 1'1, 193s, Senn No. 240,892 l z calma. (ci. rea-15s) 'his invention relatesto a ilne vextinguisher oithehandtypeof thelength of time of non-use of the extinguislier; to provideV a construction in which one end of the cylinder is enlarged wherebythe piston packing is not compressed and caused to takea permanent set when the extinguisher is not used for long periods of time; to provide a construction in which the piston maybe provided with resilient felt packing rings which will retain their original size regardless of the length of time of non-use; to provide a construction in which the felt packing' rings provided around the piston serve as a centering means for the piston and thereby prevent metal to metal contact of the piston and cylinder in which it reciprocates; and' to provide improved means for stripping the uidl from the piston rod so as to prevent slight leakf age or. dripping when the rod is reciprocated through its packing gaskets and which means is resilient and yielding so as to not become frozen' on the rod by corrosion during long periods of non-use.

An illustrative embodiment of thisinvention is shown in the accompanying drawings, in which:

lilg.` 1 is a longitudinal medial sectional view, with the middle broken out, of a nre extinguisher embodying the new improvements.

Fig. 2l is a sectional view taken on the line 2-2 of Fig. 1, looking in the direction indicated by the arrows. Fig. 3 is asectional view taken on the line 3-3 of Fig. 1.

Flg. 4 is a fragmentary sectional view of the lower end of the pumping cylinder showing the sliding piston in a position on the piston rod opposite to that shown in Fig. 1.

Fig. 5 is an enlarged, fragmentary, medial sectional view of the improved fire extinguisher showing the details of construction of the piston rod packing glands and sealing means.

As is well known in the ilre extinguisher art, it isboth desirable and necessary to have the piston, which reciprocates in the pumping cylinder for expelling theJ fluid from the extinguisher, nt

be either a total absence or a minimum of slippage of uid past the piston when reclprocated in its cylinder. It is also well mown that dueto the inherent character of iire extinguishing iiuids there is a great tendency for corrosion to take place within the re extinguisher on those parts which are contacted by the re extinguishing iuid. This corrosion will oftentimes freeze the piston to the cylinder wall when the nre extinguisher has not been in use for a long period oi time with the result .that when the emergency of re arises it is often impossible to operate the lire extinguisher and disastrous results follows.

The important problem of the iire extinguishermanuiacturer is to make an apparatus which is leak-proof when the extinguisher is not in use and at the same time have an extinguisher which unquestionably Iwill operate immediately when the emergency of fire arises. It is of course selfevident that a nre-extinguisher from which the lre extinguishing duid has leaked or evaporated out or a nre extinguisher which is frozen and will not operate in case of an emergency are both worse than having no ilre extinguisher at all.

The use of felt lpacmng rings on the working face of the piston tor making a uid tight seal with the cylinder walls has not heretofore been satisfactory for the reason that during long peri-g odsfor non-use the packing is held compressed by reason ofits tight fit in the cylinder and will thereby lose its expanding resiliency with the result that much slippage of fluid occurs past the piston during the pumping strokes.

In the present invention the well recognized dimculties have been entirely overcome by providing a piston which has substantial clearance with the cylinder walls; providing the working face ofthe piston with felt packing rings, and then having the lower end of the pumping cylinderfin which the piston normally rests when the extinguisher is closed and not in use, of larger diameter than the remainder of the pumping cylinder with the result that the packing rings are not subjected toany compression whatever when the extinguisher is not being used. Furthermore, the entire piston, when in the enlarged portion of the cylinder, will have suillcient clearl ance'with respect to the cylinder wall to prevent the corroding together of the metal parts during When the extinguisher is lnder by the packing rings and not have any metal to metal contact with thecylinder walls with the result that freezing or sticking of the snugly with very close limits so that there shall iid-piston in the cylinder is impossible.

-vWith respect to sealing the reservoir against evaporation duringnon-use, this improved extinguisher is provided with a spring pressed seal in which the complementary contacting sealing faces are rotated while being axially compressed with the result that any dirt or foreign matter on the contacting face of the sealing parts is ground into the faces or displaced so Athat a very effective seal is secured whichis maintained under spring tension during non-use of the extinguisher with the result that it is impossible for the fluid to leak or evaporate out of the reservoir.

Another problem encountered in the use of fire extinguishers having felt packing glands for the piston rod has been that of the fluid adhering to the piston rod as it is drawn through the gaskets and then dripping off in the hands of the user during the pumping strokes.

In the present invention this objection has been overcome by having the helical compression spring, which compresses the rod gaskets, fit tightly around the rod, so that it acts as a resiliently gripping fluid stripper. Due to they yieldability of the spring, it may have a snug fit around the rod, but will not freeze thereto by corrosion. Y

In the construction shown in the drawings, a cylindrical reservoir 5 has an integrally formed lower end 6 in the center of which is brazed or otherwise rigidly secured a nozzle fitting 1, having an axially disposed discharge opening 3 formed therethrough. The upper end of the reservoir is closed by a cap 9 brazed or otherwise sealed thereto in which is a filler opening with screw closure plug, not shown, in the usual manner of fire extinguishers of this character. The cap 3 has an annular collar or sleeve portion Iii, extending axially The lower end of the hollow shank 2| is flared out to provide a cylindrical sleeve 3I which surroundsy the axially slidable sleeve 22 and which is provided with diametrically opposed axially extending inwardly presenting slots 32 and 33 which receive similarly disposed ribs'34 and 35 respectively which are integrally formed on the slidable sleeve 22 whereby the sleeve and handle are non-rotatably secu'red while permitting relative axial movement therebetween.

The hollow shank 2I of the handle 2U is provided with an axially extendinglbore 36 in which` is housed a helical compression spring 31, one end of which -abuts the blind end of the bore 36 and the other end of which contacts an axially slidable iioating seal 38, the inner face 39 of which fits upon and closes one end of a discharge tube 43 when the handle is in closed position,

as shown in Fig. 5.

The opposite end of the discharge tube 40 is rigidly mounted in the inwardly projecting end of the nozzle fitting 1 with the opening therethrough communicating with the discharge opening 3, the tube 40 being concentrically disposed outwardly and having. an axial opening therecylindrical sleeve portion I3, the axial end of which terminates in an exteriorly threaded end I9, A handle 23, having an axially extending hollow shank 2|, is threaded on the end I3 in abutting relationship against a shoulder of the sleeve I3, to limit and position the parts.

An axially slidable sleeve 22 surrounds the annular sealing member I 6 and piston rod I4 in spaced relation thereto and the upper end is provided with a radially disposed, inwardly extending flange 23 which is freely slidable on the sleeve portion I3 of the annular sealing member I3. A helical compression spring 24 is provided in the space between the fixed sleeve I3 and the slidable sleeve 22 and bears between the sealing member I6 and the flange 23 of the sleeve 22. 'I'he lower end oi' the slidable sleeve 22 is provided with diametrically opposed radially extending lugs 25 and 23 which have cam surfaces on their upper axial faces for`interengaging with flange portions 21 and 23 integrally formed on the cap 9, openings 23 and 33 being provided in the flange through which the lugs may enter in the usual manner of bayonet connections,

during reciprocation thereof;

within the piston rod I4 and in spaced relation thereto. f

The inner end of the sleeve I2 is interiorly threaded to receive the exteriorly threaded axially extending sleeve portion 4| of a fitting 42 which is provided with an oppositely extending cylindrical sleeve Jportion 43 which has a free sliding fit on the piston rod I4. The space between the piston rod I4 and the sleeves I2' and 4I is pro-A videdat its upper end with a felt gasket 44, a` cork washer |45, and `a brass washer 45 bearing thereagainst. 'I'he gasket 44 isconstantly urged in compression around the piston rod I4 by a helical compression spring 46, which snuglysurrounds and yieldingly grips the rod I4, so as to strip the -fire extinguishing fluid from the rod One end of the compression spring 46 bears against the washer 45-and the other end thereof bears against a similar but smaller washer 41 which fits against a felt gasket ring 43 disposed at the other end `oi? the space, thus providing a double yielding sealaround the piston rod which is automatically tensioned at all times and which prevents substantial leakage of fluid around the piston rod during its reciprocation when subjected to pumping action.

The piston rod I4l is surrounded by a pumping cylinder 49, one end of which is xed to a rotatable head 50 and the other end of which isr similarly fixed in a rotatable head 5I. A portion of the lower end of the pumping cylinder 43 adjacent to the head 5I is of enlarged diameter, as indicated at 52, and constitutes one of the main features of the present application. The lower end of the piston rod I4 is exteriorly threaded and has screwed thereon the interiorly threaded end 53 of a tubular nipple 54. The nipple 54, adjacent the end 53, has an annular shoulder 55 which serves as one limit stop for an axially slidable piston 56 which is carried on the nipple 54. The piston 56 is looselyl retained on the nipple 54 by an interiorly threaded cap 51 which is` screwed on to the exteriorly threaded lower end of the nipple 54 and which carries a packing 53 therein retained by a thin washer 53.

The circumferential working face of the piston 33 is provided with an outwardly presenting peripheral groove which carries a pair of yielding der ene i: and cylinder as are such marine packing rings Il are compressed and have a snug working tit in the smaller diameter of the -pumpstroke of the piston rod the piston, when resting against the axial end face of the nipple Sl, will' uncover the openings 9| so that fluid may pass `thereinto, and upon the downstroke, when the piston is abutting against the shoulderv 55, Aas shown in Fig. 4, the iluid will enter through the apertures 62. A by-pass port 63 is provided for permitting part of the fluid within the hollow piston rod to pass back into the pumping cylinder 49 to help ill the same on the downstroke of the pump when the suction from-the reservoir may not quite-lill the pumping cylinder 49.

reservoir into the tube 12 and heads 50 and 5I. The laterally extending weight arm of the head 5I is also provided with a radially extending port l1 controlled by a ball lcheck valve 18 which provides communication between the passageway 13 and the lower end of the pumping cylinder 49.

The head Il at its lower end is in slightly spaced relation to the discharge tube 40 and is provided with a relatively thin brass washer 19,

The head which supports the upper end of thepumping cylinder 49 is provided with a felt packing ring or gasket 94 which is` retained by a relatively thin brass washer secured on an annular radially extending seat by rolling over vthe metal at the edge of the opening which receives the washer, as shown at 69. vThe inner edge of the washer 65 rides upon the outer surface of the axially extending sleeve portion 43 which serves as a bearing for supporting the upper` end oi the suction mechanism and which bearing, having relatively small metal to` metal contact, will have a minimum of tendency to stick and present very little friction to rotation of the head, thus providing a structure which will have freedom from freezing by reason of corrosion or the like.

The head 50 is provided with a laterally extending weighted arm having passageways therethrough with ball checkvalves which serve as suction ports for the pumping cylinder. 'I'he upper end of the cylinder 49 communicates with a radially extending port 61 controlled by ball valve 69 which leads to an axially extending passageway 99, one end of which is controlled by a ball check valve 19 and which in turn communicates with a second radially extending port 1|, the outer open end of which lies closely adjacent to the inner peripheral wall of the reservoir 5. The end of the passageway 69 opposite to the ball check valve 10 communicates with anaxially extending tube 12, the upper end of which is rigidly secured in axial alignment therewith, and the opposite end of which is similarly secured to and communicates with an axially extending passageway 13 formed in the laterally extending weight arm of the head member 5|. The lower end of the passageway 13 is likewise vprovided with a. ball check valve 14 which controls communication between the passageway 13 and a radially extending port 15, the outer open end of which lies closely adjacent to the interior wall of the cylindrical reservoir 5. n

A metal rod 19 is housed within the tube 12 and-functions to tap the ball check valves 10 or 14 oi of their respective seats when the fire ex tinguisher is inclined either upwardly or downwardly, as the case may be, thus insuringfree communication for the passage of iluid from the the inner edge of which rides upon the tube 40 'and serves as a bearing for the head 5| which has relatively little friction and thus permits free rotation of the head with respect to the tube 4i).v A felt packing gasket 89 is interposed between the axial face of the washer 19 and the opposed Y axial face of the discharge nozzle`ilttlng 'l .for

preventing substantialY leakage of uid thereof, it being understood that when the piston rod is pushed downwardly, as viewed in Fig. V1 of the drawings, the friction betweenA the piston pack-A ing 69 and interior wall of the pumping cylinder 49 will tend to slide the entire suction unit, comprising vthe heads 50, and 5i and pumping cylin-l der 49 and suction tube 12, downwardlyl against the packing 90 and tightly compress it so as to prevent leakage of iluid. Likewise during theA upstroke, the entire suction assembly Willmove axially upwardly and thereby cause the axial end face of the sleeve 43 to compress the packing ring 54 and prevent leakage at this point of the fiuid entrapped within the pumping cylinder 49.

In the operation of` this re extinguisher, ther reservoir 5 is lled with fire extinguishing fluid through an opening in the head 9 (not shown) in the usual manner. During non-'use of the fire extinguisher the cam lugs 25' and 26 are engaged under the inturned flanges 21 and 29, thus compressing the helical spring 24 between the radially extending inturned flange 23 and the annular sealing member I9 which is brazed to 'the' piston rod i4, thus compressingthe gasket I5 between the sealing member i6 and the outer axial face i3 of the sleeve Il. Thus a uid tight )fr eil'ective seal is maintained at all times which will prevent leakage or evaporation of the fluid within the reservoir past or through the opening i in the sleeve Il around the piston rod i4,

When the handle is in the foregoing described closed and sealed position, the lower face 39 of the oating seal 98 is tightly pressed against the upper end of Idischarge tube 40 by the helical compression spring 31, thus preventing any leakage or evaporation of fluid through the discharge Q tube 40 and nozzle opening 9 of the apparatus.`

When it is desired to operate the re extinguished, the reservoir portion 5 is grasped in one' v hand and the handle 20 in the other, and the handle rotated relatively to the reservoir until the cam lugs 25'and 26 are in registry with the openings 29 and 30 between flanges 21 and 28, at which time the handle carrying the piston rod I4 may be withdrawn or pulled out axially from the head endof the nre extinguisher.

Inasmuch as the felt piston packing rings 6l) have been i`n the enlarged end 52 of the pumping cylinder 49 during non-use of the i'lre extinguisher these packing rings will have remained their original size, and when drawn up into that part of the pumping cylinder 49 having the smaller diameter, will make a tight t therein which will prevent slippage of iluid past the piston. The piston 56 is-made of smaller diameter than the interior diameter of the pumping cylinder 49 Il the pumping cylinder by the packing rings 69.

During the upstroke of the piston rod, the piston 56 will ride upon the axial end face of the nipple 51 thus uncovering the openings 6I and permitting uid from the pumping cylinder 49 to pass through said openings into the hollow piston rod I4, thence upwardly toward the handle and into the open upper end of discharge tube 40 which has been uncovered and unsealed by withdrawal of the handle 29. During this upward stroke of the piston the uid which is in the pumping cylinder 49 is prevented from passing out around the piston rod I4 through the head 59 by reason of the stripping action of the spring 46 and ther resilient felt packing rings 44, 48 and 64. During such upward stroke fluid is drawn into the lower end of the pumpingcylinder 49 through the port 11 around the ball check ing rings 69, being free from compression duringy such periods of non-use, will make a tight sealing llt with the interior wall o f the pumping cylindexl 49 when drawn up into the smaller diame-v ter portion thereof which is the substantial pumping length of the cylinder.

It will also be equally evident that when the handle 29 is forced downwardly so as to compress the spring 31, the floating seal 38 will effectively close the upper end of the discharge tube 49 and prevent evaporation or leakage of the fluid thereinto. When the cam 1ugs'26 and 26 are rotated underneath the flanges 21 and 28, the sliding sleeve 22 will'movev axially downwardly toward valve 18, it being understood of course that fluid is drawn in andfills the passageways 69, tube 12, and passageways 13 either through the radially extending ports 1I or 16 depending upon the position of the nre extinguisher. If the discharge end of the extinguisher is pointed down, then the ball check valve 19 will rest upon its seat, as shown in Fig. 1 of the drawings, and the rod 16 will tap the ball check valve 14 off of its seat and Athus open communicationthrough the intake port 16. Conversely, if the discharge end of the extinguisher is pointed upwardly, the ball valve 14 will rest upon its seat and the rod 16 will tap the ball check valve 19 off. of its seat and thus provide suction opening through the port 1I. I

When the piston has reached the upper limit of its stroke it is then forced downwardly by pushing in of the handle 29 at which time the axially slidable piston 56 abuts against the shoulder 55 of the nipple threaded on to the end of the piston rod I4 and thus opens communication to the interior of the piston rod I4 through the radial ports 62. As the fluid is forced into the hollow piston rod I4 and thence out through the discharge'tube 49 a portion of it is by-passed through the port 63 and into the pumping cylinder' 49 back of the piston so as to help illl the pumping cylinderon the downstroke, as it has been found that during thisY downstroke, it is at times desirable to supplement the uid being brought in through the port 61 around the check valve 68.

During the downstroke of the piston, the friction between the packing rings 694 and interior Wall of the pumping cylinder 49 carries the entire suction assembly axially downward, as viewed in Fig. l, so as to compress the gasket 89 and thus prevent leakage of fluid from the lower endl of the pumping 'cylinder around the discharge tube 49 which would otherwise occur by reason of the substantial clearance between the outside of the discharge tube and the head 5I through which it passes.

From the foregoing, it will be clearly evident that it will be impossible for the piston 66 to become frozen to the interior wall of the pumping cylinder 49 during long periods of non-use of the fire extinguisher, and furthermore that the packthe head 9, as shown in Fig. 1 of the drawings, thus compressing the spring 24 which'yieldingly holds the annular sealing member I6 and. gasket I5 tightly upon the sealing face I3 offthe sleeve member II. V

It is to be particularly noted that during this latter closure, the sealing member I6 carrying .the packinggasket I5 is not only axially compressed on its cooperating sealing seat, but by reason of the member I6 being secured to the piston rod`I4 and hence rigid with the handle 29, the contacting surfaces of the sealing members are rotated with respect to each other, thus grinding out any dust or foreign matter which may be on their contacting faces and effecting a superior seal at this point somewhat analogous to a rotated grinding fit. of the contacting faces. The cylindrical sleeve portion I2 is provided with a plurality of axially extending slots or notches 99 through which the fluid that is stripped from the piston rod I4 may return to the interior of the reservoir.

Although but one specific embodiment of this invention has been herein shown and described, it will be understood that numerous details of the construction shown may be altered or omitted without departing from the spirit of this invention as defined by the following claims.

1. In a ilre extinguisher, a pumping cylinder, a piston reciprocable in said cylinder for expelling fluid from said extinguisher, said piston having a groove in its circumferential face and felt packing rings in said groove, said cylinder having a portion of enlarged diameter and the relative sizes of said cylinder, piston, and packing .rings being such that said packing rings are under compression when said piston is in the smaller diameter of said cylinder and are relieved of compression when said piston is in the larger diameter of said cylinder.

2. In a fire extinguisher, a pumping cylinder, a piston reciprocable in said cylinder for expelling fluid from said extinguisher, said piston having a relatively close working fit within said cyl-

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