US1689980A - Dry-pipe sprinkler-system accelerator - Google Patents

Description

Oct. 30, 1928. 1,689,980

E. TYDEN DRY PIPE SPRINKLER SYSTEM ACCELERATOR Filed Feb'. 15, 1926 2 sheets-sneet 1 Oct. 30,1* Vv1928. n'

Y E. TYDEN DRY PIPE sPnINxLER SYSTEM AccELERAToR 2 Sheets-Sheet 2 Filed Feb. l`5, 1926 AZS 5215021226: .5'.

ess.

qui

the accelerator.V j l r The drawings .showithe niain rahecasing A, with the Watersuppiy pipe, B,and,fpipe= C, leadingto the lsprinkler `head systeur,ailf

'in said casing', ,being reerred to as the (Z, entering the casing, opens into Valve chamber "Valve, Of-,herernatter more p sage, G3, into the chamber, rh

Patented v, Oct. 30, 1928.

UNiTED fsTATEs- PATE EMIL TYDEN,v oF EVANsaJoN, I'LLiINoIs'.

`"mur-PIPE srRmKLER-sirsrnm AGCEILERATOR.

i Lppucauonnied February ,The purpose of this inreution is to provide an improved constructuni of an accelerating device fora dry pipe sprinidersystem; It

consists of the elements and features `of con-l struction shownand describedk as indicated in the claims. f

In the drawings Figure l is a trout elevation ot the dry' line `eti-4 i on be rond the main Water-controiiin9'vaive .a

e r 4 i "3 pressure region ofthe system.

Connected with thejair pressure regione"` the connection as shown beingrinade by pipe,

` D, which is y connected mitin and' ieaes from,

the cavity ofthe main Valve casingeis the accelerator device indicated as to its entirety,` by `reference letter E, and con'iprising anA attached part, F. ,r

Ithis accelerating,lr i device` c oi casing having two cha1nbers,l0an which the air pressure region et thesy: communicates,- uari5`fA described, 1 by and (1,3, in .said casing.

oipassages,

the pipe, D, by vcoiniection Wit-h the -pipe 1iinb,1 46, hereinafter mentioned, said pipe, i i at a port el, 'which 0*, Vdiei-ein -a 'L' i de l r der@ scribed as its mounting' connectionsfroopera rta la waivev sr (il, having a port, 621eadin0' c "by, its periphery.v line 3--3 on chambers come inunicate `With the air` pressure regnen of the 1 a system by means ot,apipepd,lead-nigtrom ali one, as shown f15, 192e. serial No. 88,167.

one, as shown at 16; andupon thisouter Wall of the using, E, there is appiied av cap, e, havia in its applied i'ac-e a large cav-ity, 17, with itsiarge aperture reggisteringv with the aperture, lt, in the Wall of the chamber, 11, v and having' a small aperture, 18, registering with the aperture, l5, inthe wail uof the chamber, l0. A duct, 19, connects .the..cavity,

.17, With the aperture, 1S. :in thecavity, V17,

there is mounted a" diaphragm casing condprising two inenibers, 2O and 21, between which a flexible diaphragm, is cianipefdV The diaphragm casing" member, 21hasapertures, Q1, :tor communication. oi the diaphragm chamber at one side 'ofthe diaphragm through the duct, 19, With- 'the chan'iber, 10, andthe diaphragm casingy ,ineniheig 20,; has apertures, 20, 'for commu nica-tion ot' the diaphragm chamber at the other-'side of the dia ihraoni With the chain- Y M zo ,p Y Y ber, 1l. e n a The pressure troin'the air pressure region of the system, itwillybefseen, reachesthe chamber, li, t'reeiy through the port, 63, so r that changes inthe pressure in said air" presf sure regionwiil. be experienced proinptyin ,i

said chamber, 11.

But saidprcssure reaches NT omcEL-j the chamber, 10, by Way of thepassages, 13

and 12, and a fitting, H, which is interposed," inthe passagel2, or between the saine and posed thereinhaving an aperture,fh1, con#` a stituting thesoie access of pressure .from the lduct, l2, to the chamber, l0. The detail con struction of this iitting Will be understood ,troni the drawing as comprisingr plugs, H1,

H1, screwed into the oppositeends ot fthe body nieniberpH, of the titting, Veach carrying a perforated or Woven wire strainer element, h2, for ,guarding the restricted a perture, h1, againstch hing by dust particles. f

vits opening-into the chaume-1310, the passagel -for pressure communication through the fit` tinQI-I, beingaestricted `by a disk,h, intere` Atfwili bel seen that theqdiaphragm, 2Q,

-constitutes in effect an impertorate'partition separating the two chambers 10 and 1l, so far as air communication betweenthein is con#1 i cer-ned, but subject to the communicationfoff,

ot "the pressures- Which. reach the opposite s ies, ot the diaphragn'i vthrough th'erespee .Y pressure from the onetothe other by Virtue@ T i chani- Y tire apertures ot the diaphragm casing nit-:lin-` Y ber. In the diaphragm casing atthe sideto# Ward' the chamber, 11j, there isi mounted a5 f Y f1 plunger, 24,-har1ng an expandedhead, 25f0r seating on the diaphragm, the plunger itselt obtaining bearing and guidance in a. bearing, 20", with which the diaphragm casing member is provided at its center projecting into the chamber, 11. The end of the plunger protrudes from said bearing lor encounter with the. inner end of an operating member. t), which. as hcreinaiter more particularly described, extends air-tight through the wall of the chamber, 1l, for a function hereinafter more particularly explained.

'the part. F. primarily ati'ords a, eounectvitm with the air pressure region ol' the system through which itis vented to the atmosphere g :md lor that purpose it has a cavity or passage, 39, which opens at one end through a port, fl-1, at which the pipe, D. is connected, said pipe leading. as hereinarlter mentioned, trom. the air pressure region of the systeni. This port. il, is controlled by avent valve, if), cti-operating with a scat. ft2, tormed at the outer side ot said port` 41. At the side ot the passage, 23S), said passage opens to atmosphere through the port, lt), wherebywhen the valve lil. is open. the pressure of the air pressure region ot' the system is freely and promptly vented and relieved.

The valve, lo. has its stein, guided in a bearing seen at 18; and below that bearing the casting. F, is ehambered, as seen at. 49, to accommodate a coiled spring, 5l, which reacts between the lower side of said guide bearing, 418, and a collar, 5U, screwed onto the lower end ot the, valve stem. Llel, for initially holding the valve normally seated, and retractin g it 'from open position to its seat on which it is adapted to be. held b v the air pressure ot thesystem when the entire apparatus is set Incidentally the collar. 50, by titting quite closely approximately piston-wise in the stem chamber, 4S), which is cylimlrically bored, operates to prevent sudden retraction ol' the valve to its seat with ay hammer blow there on. and causes it on the contrary to seat with conmaratively slow movement without hammer. Below the spring chamber the part, F, has a cavity. open at the lower end where it'. registers with an. aperture. 2G. in the flange, 2i". which projects 'trom the web of the hol- `low base, 28. ot the easing, E. in which base the weighted lever, 122, `whose Function is hereinafter described, is pivotally mounted and housed.

An important purpose of the construction. being to cause the vent valve t3 to be opened by the movement of the operating part, 30, which results from the movement ot the diaphragm, 22, upon the. limited. reduction ot the pressure in the air pressure region ot the tem. is effected by the operating connections from the part, 30, to the vent valve stem, which will now be described.

Said member, 30. is pivotally mounted in the lower wall of the chaniber, l1, tllrongh which Wall it protrudes and is rendered airtight at its protrusion therethrough by means ot'l a tlexible sleeve. 90, whose upper end is clamped tightly about an enlargement, 91, of said operating.r member. 30, while the lower end is similarly clamped about the boss, 92, formed around the aperture through which said operating member protrudes trom the casing. A convenient construction for the purpose is that shown, which consists of a plug, 95, which closes an aperture, titi. in the lower end wall ot the chamber, 1l, and which has at its upper side the boss. 92, mentioned, upon which the lower end of the ilexible sleeve, 90, is made fast, said plug, 95, being secured in position closing the aperture, 9G, by a screwed-in follower. ltlt). This t'ollower, 100, is apertured to admit the upper forked part, 110, of a weighted bell crank lever. 111, said lever constituting a latch member having its latch nose. 112. engaging the tlange, 105. which is formed at the lower end of thev follower. 100, by counterboring its upper end portion. This bell crank lever is t'ulcrulned near its angle on a weighted lever, 122. which will be shortly described` and has its horizontal arm quite heavily weighted, as seen at 113, 'tor eil'ecting automatic engagement ot the latch nose. 112, with the flange` 10.3. as described. Said end of the bell crank lever is engaged by the lower end of the operating member, 30, ilor disengagement oi the latch nose by pivotal rocking of lsaid operating meniber, which occurs when ,its upper end is moved inward by the inward thrust ot' the plunger, 24, which results from the reduction of pressure in the chamber, 11, consequent upon the reduction of the pressure in the air pressure region ot the sprinkler system, which may be caused by the opening of a sprinkler head. The weighted lever, 122, is fulcrumed near one end on pivot studs. of which one is indicated at 123, set in the wall or web, 28. ot the casing, E, having its opposite end weighted as seen at 122 for gravity movement for giving a powerful upward thrust by the shorter end oi the lever. for opening the vent valve by connections. For this purpose there is pivotally connected to the lower end of the valve stem, i4, a swingin link, 130,1which extends down through the open lower end of the chamber. 52, for engagement with a stud, 131. on the lever, 122, said link terminating in a cam projection, 130, at the upper limit of which there, is formed an abrupt shoulder, 130", with which the stud, 131, collides after the initial down ward swing of the weighted end of the. lever has caused the stud, 131. operating on the cam terminal, 130, to swing the link, 130. a short distance to the right at its lower end; and upon the encounter of the stud with the shoulder 130b the l'urther down-swing of the weighted en d of the lever causes the stud, 131, to give an upward thrust to the link. and thereby to the valve stem, 44, liftingr the val ve,

43, vfrom its seat, and accomplishing the venting which is thepurposeof the connection.

, Since such venting ofthe air pressure causing the main valve to be openedjby Vthe water pressure would cause the system to `be flooded withwater, and since in the absence of preventive Vmeans the water coming to occupy the entire air pressure region oi' the system would follow the conduit through which the air pressure reaches the accelerator chambers, and flood those chambers, a urtherpurpose of the construction is to cut off the communicationfrom the air pressure regionof the system to ,the accelerator `afterthe vent valve is opened as above described. ,The construction for this purpose will now be described.

The valve, 60, which controls access of the air pressure to the accelerator chambers, is held normally open by spring device 66m, hereinafter more particularly described, which reacts for that purpose between a disk,

66p,` loose on the stem of the valve and stoppedl and 66, ofgwhich the part, 65, is screwed` into the part, 66, for clamping said disk be tween the shoulders `of the two parta Thel part, 66, is hollow from end to eiid,they part,`

65, beingr screwed into one end closingv the cavity and leaving the remainder of its length to the opposite end operating as a 4socket ory guide bearing, as indicated at 66a, .for the end ofthe stem, 7 7 Oia disk, 68, which is secured to thecentral portion` of a diaphragm, 69,` which partitions a ,diaphragm chamber formed lby a recess, 70, in theeuter surface of the left-hand upright end of the part, F, and a tio-,operating recess, .71',in the right-hand face of an applied vcap plate, 72, the two recesses being bounded by annular seats between which the margin of the diaphragm is clamped by bolts which securethe. cap plate to the part, F Said cap plate has Vat the lower side a. cavity, 7 3, `opening at one end into the recess, 71, and at the lower. end threaded for connection afforded by a pipe, 74, `which leads from a part of the system to which the water pressure has access only when the` main valve isopen, and which is `connected for drainage when the water supply is cut off.

Thecavity'lthrough which stem, 77, extends `from its end guided in the socket, 66, of thestem ofthe valve, 60, traverses at Vright anglesthefcavity, 52, and is bored at the end next to thejdiaphragm chamber to house and form a stop shoulder for a spring, 78, which reacts between said stop shoulder, 79, and the centralhub of the disk, 68, for holdingthe Adiaphragm normallyflat, and the stem, 77, `out of touch with the end of the part, 65, ojf the stem of the valve, 60, whichforms the bottom of the socket in which the stem, 7 7, is guided.

the diaphragm carries a cioss-pin, 77h, engaging slots, 130", -l

in the two fork arms oi' the link, 130, so 4that the sideI swing of the link, caused by the encounter of the stud, 131, with the cam terininal, 130, of the link, thrusts Lthe stein, 77, into touch with the end of the member,6, ofthe stem ofthe valve, 60. Simultaneously upon the venting of the system pressure by opening the vent` valve, 43, the water supplyY pressure enters and quit-e rapidly follows up the escaping air in the system, and, reaching the diaphragm, 69, through the pipe, 7 4, forces the diaphragm inward causing the stem, 77, to thrust the valve, 60, ully'to its seat, cut-ting off access ot the system pressure,

and thereby preventing the entrance olwatei f the link, 130, laterally, dislodging the shoulder, 130", from the stud,131,whereupon theV spring, 51, reti-acts the vent valve, 43, toits -seat,'preventing the waste of the water which would otherwise occur through the vent dport, The stress of the spring, 78, upon the stein, 7 7, transmitted to the link,130, bythe'engage# ment of the cross-pin, 77", in the slots of the fork arms of the link, holds the link stressed against the side of the stud, 131, at'the posi#y tionof the link for holding the valve, 60, closed; and the weighted lever, 122, pendent, holds the stud, 131, in the positioniior thus locking the valve, 60, closed until said pendent y lever is manually lifted for resetting the apparatus after the system has been drained of the water, and it is desired to recharge the! air pressure regionwith airiinder pressure.

The specic detail form yof the Vspring device,66m, for holding the, valve, 60, `normally open, is a crimped or corrugated spring tube commonly known as a sylphon, which therefore enclosesa chamber around the valve stem, 65. It will be understood that the sylphon device is itself open at both ends'and that the disks, 64 and 66p, do not close it air` tight at either end; on the contrary, the sylphon is at all times, as necessary for its normalspring acti0n,-open to discharge and entrance of air as it is compressed and reacts by expansion. It is therefore open to the air bers; and it will be understoodthat this air l derivedthrough the diaphragm, 69, for seat' ing the valve, GO, and for holding it seated, and reacting for opening said valve. For convenience of installing the valve, 60, with its twoanembered stem, (35, 6G, and this chamber spring device by mounting in the casing, E, there is provided the casing, GG", which encompasses and encloses the sylphon spring, 66m, and affords a guide bearing for the hollow stem member, titi, and a stop for the same in the direction of thrust ot' the sylphon spring. as seen in Figures 2i. 4- and 5. This casing. (36", is screwed into a bored and threaded recess in the casing casting, E, and is thereby in position for entry of the hollow boss at its left-hand end in which the Istem member, 66, obtainsl seat and guidance in an aperture provided for it in thc proximate wall of the part., F, when the latter is assembled in permanent relation to the easing, E. The purpose of this specific construction is to eiiectually protect the valve. (50, from any access of water to it. or past it, into the accelerator chamber.

As mentioned above, the pipe` 7l, for water connection to the (liaphragm chamber to operate the diaphragm, 69, for the purpose described must lead from a point in the s) 'tem to which the water pressure has access only when the main valve is open for admitting the pressure to the supply system, and since it is desirable that the diaphragm chamber should be drained to permit the diaphragm to recover its normal position and release the valve, G0, when the system is drained of water, and is to be reset with proper pressure in the air pressure region, the pipe, 74, should lead from a point in the system which is open for drainage when the system is drained preparatory to resetting. Both these conditions are met by connecting the pipe, 74, with the customary alarm pipe, 80, which leads from the interscat chamber, Si, of the main valve casing, in which there is shown the familiar construction for drainage of said interseat chamber when the main valve is seated, and when the system is set for operation, consisting of the drainage connection, 85, for closing which there is provided a valve 8G, which is held open when the main valve is closed by the finger, 88, extending from the main valve through the main valve port for encounter with one end of the lever, 89. by

which the valve, SG, is carried at the other end.

A v ery important consideration determining the construction for controlling the valve by which the system pressure is admitted to the accelerator chambers, is that it is liable to occur through inattention that the system air pressure by reason of some minor leak declines so slowly that the differentiation of pressure in the two chambers of the accelerator does not occurg-that is, the restricted communication between the two chambers is equal in flow capacity to the leak; with the result that this decline of pressure does not cause the accelerator to act for venting the system air pressure, and otherwise operating the device. In such case the leali continuingr until the system air pressure becomes less than the water supply pressure, the main valve opens and the system is flooded when there is no :Tesina-that no tire to be extingu'f":-d: and in the absence oi preventiw means, the entire system being filled with water, the *at'er follows where the air pressure had previously and normally followed. into the accelerator chambers, and that: device becomes flooded, with the elliect frequently otA deposit ot' sedimentary material at `'arious places in the device, and in any event the accumulation of water in pockets from which there is no drainage and from which none can be readily provided. In such case it is practically necessary to dismount and disassemble the entire accelerator in order to clean it of a deposit. and restore its eflicieney.

An important purpose of the construction shown in the drawings is to overcome this defect and prevent the undesirable flooding of the accelerator. The specific means for this purpose consists in the pressure connection afforded by the pipes. S() and 7i leading from the chamber, Si, ot the main valve casing to the dialihragm, (if), connected as descril'ied for closing the valve, (30, cutting oiil access of both air pressuwy and water pressure from the accelerator chambers.

It will be observed that the eliiciency of the construction shown for seating the valve, (50, under the circumstances indicated, depends upon the fact that. t he pressure which operates for seating it, being derived from the same source as the pressure which normally operates for holdingr it open ,--is thus operative by virtue of the excess of the area of the diaphragm over that of the valve. And it will be further observed that the result desired.- viz, the closing of the valve, (it), when the main valve is opened so that from that opcning there. may not result. access of water to the accelerator chambers,-will be obtained whether the pressure which operates through the open main valve in the chamber, 84, and thence through the pipes, 8O and 74;, to the diaphragm, (39, is the renmant of air pressure in the system, or is the water pressure from the supply pipe, and that therefore the valve, (it), will be closed upon the (mening of the main valve, even though by oversight or intention the water supply may at that time be cut oli' by the closing of the shut-oit valve which is customarily present (but not shown in the drawings) in the water-supply pipe, Bg that is to say, primarily and fundamentally it is the access of pressure, from whatever source from above the main valve, to thc diaphragm which is atlorded by the opening movement'ot the main valve, that accomplishes the result described.

inn

` ment upon limiteddecline of pressure in the air pressure region of the system; a movable part caused to be moved by said means; an atmosphere vent portand a conduit leading thereto romthe airnpressure region of the system; a valve controlling'said` port positioned forbeing normally held seated by the pressure in the air pressure region of the sys- ,y

`tem, and operative connections `from said vzo movable part foropenings'aid valve against the air pressure of the system; means for automatically locking said valve at open position, andV means loperated by the Water pressure, admitted as theresult of venting the air pressure,` for automaticallyY releasing the Y Vlocking means to cause said valve to be closed y `means caused to" operate for producing move- Y vbythe pressure resulting in the air'pressure region, from the admission of the `Waterpressure.

trolling valveftherein, adapted to be held seated against the Water pressure by the-air pressurein the system, a device comprising ment upon limited decline of pressure in the air pressure region of the system; a movable part caused tobe moved by said means; an

` atmosphere vent port 'and `aconduit leadinglthereto from" the airpressure region of y thesystem; a valve cont-rolling said port y yto permit the` vent "valve to'be closedby mi und yielding means kfor holding it normally seated ;operatingconnections from said movable part for openingr said valve; means forV automatically locking said valve at openpo'sition, and means operating automatically upon the admission ofthe Water pressure to the system for/releasing said lockingmeans said normally closing means.y 1 i 3. In a dry pipe sprinkler system, in combinationwith a ,valve casingI and a Water controlling valve thereim adapted to be held seated againstthe Water pressure by the air .pressure inthe seat-a device comprisingmeans causedto operatefor producing movement upon limiteddecline of pressure in-the Y air pressure region of thesystem; a movable y part causedto move by said means; a port for j venting theair pressure region vof the system;

a normally seated vent valve controllingsaid 1port;poperating;connections from said movable -partforV opening the ,vent ,valve upon decline of pressure in the air pressure region;

y automatic means for lockingl said vent valve at,A open position;-a valve` for controllingac- `cess of system air` pressure tothe `firstmentioned device; Voperating connections rttor clos-V 2. Ina dry pipesprinkler systenn'in combination with a Valve casing and a Water-con- `ing said last'mentioned valve comprising a lpart arranged for deriving valve closing movement consequentupon theventing ofthe Vair pressure, said operating connectionsbe'- ing connected also for releasing the vent Valve locking means.

In the construction definedinclaim l, a normally open valve controlling communication of the accelerating device with the air pressure region of the system, connections operated by said movable part for seatingI said valve .in the movement for opening the vent valve, and means'in said connections 'for locking `said normally open valve at seated.

position WhileV thevent valve is open; vvhereby air pressure to the acceleratingvdevice' is automatically 'cut off When said system air pressure is vented to the atmosphere;` s

5, In the'construction deiined in claim l,

afvveighted lever Whichis normally locked at upheld position otite Weighted end; means operated by'said Vmovable part for re-l leasing the lockingfmeans to permit the lever `to fall; the connections Vfor `operati-ing" the,

vent valve being engaged with said Weighted lever by means of which the falling loff-the.

lever forces open the vent valve, and the lever at 'fallen position locks the vent valve open;

said connectionscomprising a linlzcon'nectedf at one end With the vent valve stem and4 attlie` other end engaged by the lever forlongitud inal thrust vto open the vent valve, and for simultaneously swingingdaterally about said pivotal connections; a valve which controlsaccess of thesystem air pressure to the accelerating device, and means engaged With :said link and connected With said last men-f tioned valve orclosing said valve infthe lateral movement of the link'ivhich occurs y in theV thrust movement by ,which the vent y is opened.

6.V In the construction dened in claim4 l, a

valve which admits the systemair pressure to Y the i accelerating device ;A the connections Which are caused to operate by theV movement of said `movable part for opening the yvent valve being adapted for simultaneously closing said air-pressure-admitting; valve and comprising the means :tor locking the vent valve open; a chamber having a movingvvall ivhose cavity communicates with a part of the system to which thewater pressure has access only'upon the main valve being open,

and operating connections from' said moving` Wall constituting the means for releasing the vent valve locking means; whereby the vent valve closes when the Water pressure admitted to the system, for preventing thewater Wasting at the vent port, and thewater is,

simultaneously excluded n, from the `acceleratonL 7. In the construction deined in claimi; a

valve torcontrollingaccess of the system or pressure to the accelerating device, means for closing said valve connected for such closing l zo movement with the vent valve opening means, and means operated b v the water pressure admitted upon venting the air pressure tor automatically locking said valve closing means in valve closing position.

tw. The structure delined in claim l havinkcr an alarm operating' water connection leading .from a point in the main valve casing at which the intake of such connection is cut oil from both the air pressure and the water pressure when the main valve is seated and is open to the water supply pressure when the main valve is open; a valve which controls access ot' the pressure from the air pressure region ot' the system to the chambers oi. the accelerating device; and means tor seating: said valve connected to said alarm operating water pressure connection. y

9. In a dry pipe sprinkler system, in combination with a main valve therein mounted and connected for being opened by the water supply pressure and held seated by the system air pressure, said system having;r a drainage chamber which said main valve when seated cuts oli' from h oth the water supply pressure and the system air pressure, and to which the water pressure has access when the main valve is opened; an auxiliary device and a conduit for communicating the system air pressure thereto: a normally closed vent valve in said conduit Vl'or ventinar the System pressure to the atmosphere; chambers in said auxiliary device to which said system pressure is communi 'ated through said conduit; mechanical connections which are actuated upon decline of the system air pressure for opening the vent valve and holding it. open against the normally closing means; an element adapted to he moved hy the water pressure, and connections from the drainage chamber for so movingr said element, and operative mechanical connections trom said movable element to the means tor holding the vent valve open for releasing the vent valve to permit it to be closed by the normal closing means.

10. In a dry pipe valve sprinkler system, in combination with a main valve casing: and a main valve therein mounted and connected for beingopened hy the water supply pressure and held seated by the system air pressure, said system ha vintr a drainage chamher which the main valve when seated cuts ott trom both the water supply pressure and the system air pressure. and to which the water pressure has access when the main valve is opened; an auxiliary device havin, T chamhers; a conduit through which the system air pressure is eonnnunicated to said chambers; a valve controllingr said communication: said conduit having an atmosphere vent port and a valve controllingV said port: means brought into operation by Said auviliarv device tor opening the vent valve and holdingr it open; an element adapted to be moved b v fluid pressure and connection from the drainage chamber tor so movingr said element, and mechanical operating connections trom said n'lovable element 'or releasing the vent valve from the means holding it open` and closing:r the valve controlling access of pressure to the chambers of the auxiliary device.

ll. In a dry pipe sprinkler system, in combination with the main valve casing and a main valve therein mounted and connected 'lor beine` opened by the water supply prcssure and held seated hy the system air pres- .surel` said casing;r having a drainage chamber which said main valve when seated cuts oti from both the water supply pressure and the system air pressure and to which the water pressure has access when the main valve is opened; an auxiliary device and a conduit for coimnunicating the system air pressure thereto; a normally closed vent valvel in said conduit for venting the system pressure to the atmosphere, said valve positioned with respect to its seat for helingY held seated by the system air pressure; chambers in said auxiliary device to which said system air pressure is communicated through said conduit, a, normally closed shut-oil valve lor controllintr the system air pressure connect ion to the chambers of the auxiliary device; mechanical connect-ions which are actuated upon decline ot the system or pressure i'or opening the ventvalve and holdincr it open against said system air pressure; an clement adapted to be moved by the water pressure, and connections from the drainage (,hambcr for so moving said element, and operating4 mechanical connections Alrom said movable element to the means for holding.; the vent valve open l'or releasing aidvalvc, said (,:onnections extending to and simultaneously operatingr said normally open valve for closing the same when the vent valve is opened.

l2. l'n a d ry pipe sprinkler s vstem in combination with a valve easing and a water-controlling valve therein adapted to he held heated against the water supply pressure by the system air pressure, said system comprisinga chamber which the main valve when seated cuts otl from both the water supply pressure and the air supply pressure; a conduit leadimcr from the air pressure region of the system l'or connection with an auxiliary apparatus. said conduit havin" an atmosphere vent port, a valve controlllner said port which is normally closed, means actuated upon decline ot the system air pressure for opening the vent port-controlling*r valve. means for locking said vent port-controlliner valve in open position, the connections for causingr the closing of said atmosphere vent valve operating for that purpose b v releasing said locking means. Y

13. In combination with a dry pipe, sprinkler system, an accelerating' device for hastenine reduction of pressure in the air pressure region of the system having a passage for communication with said region and adapted to beset 1n operation by decline of pressure in said region, the system compris-V ing a conduit connected with said air pressure region for freely venting the pressure therein to the atmosphere; a vent valve controlling said conduit, said accelerating device coinprising a chamber toy which the pressure V'from the air pressure region has access, a movable,

part mounted for movement in response to change in said pressure reaching said eha1nber, and mechanical connections from said movable part for causing the opening of said atmosphere vent valve, said connections compris'ing a part extending. from Within said chamber and protruding airtight out through the Wall thereof, and other parts eX- terior to said chamber brought into opera tion for opening said atmosphere vent valve .by said protru ing part, said exterior parts 1

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