US1679404A - Constant-alarm device for alarm valves - Google Patents

Description

Aug. 7, 1928.

H. G. CARLSON CONSTANT ALARM DEVICE FOR ALARM VALVES Aug. 7, 1928.

1,679,404 H. G. CARLSON l CONSTANT ALARM DEVICE FOR ALARM VALVES Filed Feb. 4, 1926 2 Sheets-Sheet 2 fw@ F57 Afro/wmv Patented Aug. 7, 1928.

UNITE STATES PATENT OFFICE.

HJALMAR G. CARLSON, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO ROCKWOOD SPRINKLER COMIPANY 0F MASSACHUSETTS, OF WORCESTER, MASSACHUSETTS, A

COREORATION OF MASSACHUSETTS.

CONSTANT-ALARM DEVICE FOR ALARM VALVES.

Application filed February 4, 1926.

When water spurts from an opened sprinkler on an automatic sprinkler system it is important to have a continuous alarm sounded. The usual means provided consists of three elements: a check valve in the main riser pipe, having a grooved or annular seat, an automatic drip-chamber connected by pipes to both the groove and to an alarm means such as a water motor or electric circuit closer operating a gong. The drip chamber has a valve-controlled waste outlet for wasting part of the water as enters, to slow down the rate of lilling it completely. The purpose of the drip chamber is to prevent the gong from being rung by a water hammer. lVater hammer is the popular name given to the sudden risc in pressure which occurs whenever the rate of flow of water in a supply system is suddenly reduced. Such an increase of pressure will cause the check valve to lift and admit water to both the system and the drip chamber.

It has been found in practice that the time of duration of a water hammer is quite variable and depends both upon its force and upon the amount of air trapped in the eX- tremities of the sprinkler pipes. The more such air there is, the longer time it takes a given rate of How of water up the riser to cease its upward motion and start back again under the influences of gravity and the compressed air. The return wave of flowing water re-seats the valve, thus cutting ofi`1 the supply of water to the drip chamber. So desirable is it to prevent water hammers from causing the alarm to ring that it has been the custom to provide capacityv enough in the drip chamber to prevent the water from completely filling it even under the most adverse conditions produced by such hammers.

While, however, a sufficiently large drip chamber will solve the foregoing problem, it introduces a new trouble for such increase in size is in part itself the cause of discontinuous ringing of the gong when the upward flow of Water by the check valve is Serial No. 86,072.

due, not to Water hammer, but to an open sprinkler. ure of the gong to ring because of the suction on the back of the check valve induced by the How of water( through the groove when the valve has opened just enough to supply one or two open sprinklers. lVhen a sprinkler opens the firstrush of water therefrom is not caused by the outside water supply pressure, but by the air bottled up 'in the extremities of the sprinkler lines. This air pressure must fall a few pounds per square inch before the water supply pressure can overcome the differential load on the two sides of the check valve, caused by the presence on its under side. The consequence is that when release takes place the valve bounds open clear to its eXtreme position and remains there until the motion of the water by it is arested by the rising air pressure and a return wave or How takes place. Then the valve may be slapped back to its seat again before the drip chamber has been entirely filled and an alarm sounded; or this action may be sufficiently sluggish to occupy more than enough time to fill the drip chamber and ring the gong, only to then occur and stop the water supply to drip chamber and gong, thereby stopping the alarm. It was to correct this action that the device shown in Patent Number 1,051,266, patented January 2l, 1913, was invented by George I. Rockwood. In that invention a small auxilliary check valve, having a capacity for supplying two or three sprinkler heads, was piped around the main check valve, the purpose being to pr vent most of the above described return wave of the Water after the small check valve has opened. This was effected by so throttling the water supply through the auxilliary check valve that the purely in ertia effects of the stream of water in the riser were reduced to a minimum.

Experience has shown, however, that in certain circumstances there may be very much the same intermittent ringing or absence of ringing as when only the large Indeed it may cause entire failmain check valve is used. The small valve diminishes but does not do away entirely with the diiculties described.

The principal object of my invention is to provide automat-ic and positively operating means for controlling the reseating of the auxiliiary checkA valve of the Rockwood type of alarm check valve during the period of existence of such return wave as there is when the auxilliary check valve opens in response to the flow from an opened sprinkler.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which Fig. 1 is a central sectional view of an alarm valve of the Rockwood type with a preferred embodiment of this invention applied thereto; in the position wherein the alarm valve has iust'becn closed by a water hammer and the auxiliary valve is just beginning to close.

Fig. v2 is an elevation of one side of the same;

Fig. 3 is a sectional view on the line 3-3 of Fig. 4; `and Fig. 4 is an enlarged view of part of Fig. 1.

I have shown this invent-ion as applied to a well known type of alarm valve device comprising the casing 9 and the valve, which consists of two plates 10 and 11. The valve rests on a circular valve seat 12. The area of the valve on the under side, which is exposed to the main water pressure, is less by the area of the seat than the area of the valve on the upper side, which is subjected to substantially the same pressure above. In other words, it is a differential valve which will remain closed if the pressure on both sides is the same. This valve is pivoted at The valve scat 12` is provided with a groove 14 which, in this case, as usual, is connected by a pipe 25 with an alarm bell 26 and adapted to operate the same when the valve opens and this groove is exposed to the pressure of the water in the system. Thisy construction, although commonly used, is open vto the objection above specified and is also affected by the fact that the current of waterirushes by this groove at a high velocity, thus at times relieving it of some of the pressure. y Al by-pass 15 is provided allowing the Water from the system constantlv to enter a chamber 16 outside'the valve chamber so that `this chamber will remain Linder the pressure of the water in the main. This chamber has an opening into the interior of the valve casing which is provided with another vdifferential valve 17 having a higher ratio oi difference between the two areas ,than is the case with the valve 11, as shown in Fig. 1. Therefore the valve 17 will open under a lesser reduction of pressure above and it only one or two sprinkler heads are open this valve 17 will open and allow the water to pass by into the sprinkler system even when the valve 11 is closed. All this is shown in the said Rockwood patent.

The valve 17, besides closing the chamber 1G, also closes the end oi a tube 19 connected with a pipe 2O which is connected with the alarm pipe 25 to which the water from the groove 14 Hows. Therefore the alarm will be operated by either or both. The valve 17 is pivoted at 21 on a lever 23. An adjustable limit bolt 22 is provided for limiting the amount of its motion inwardly about its pivot. This arrangement minimizes the difficulties above specified but does not entirely eliminate them if only.the parts that have been so far described are employed. Tt will be understood of course that when the valve 11 opens, thepressure on the valve 17 will close it and the operation of the alarm will be provided for only from the groove 14.

For the purpose of preventing the sudden closing ol the valve 17 and thus allowing the water to flow through the pipe 20 for a longer period ol' time so as tocause the alarm to operate continuously. provide a fleX- ible diaphragm 30 in a chamber 31 at the side of the valve casing. The water is admitted to the inner side of the diaphragm by a passage 36. Secured to this diaphragm is a tube 32 extending through the passage 36 and pivoted at 33 to the lever 23. At the outer end of this tube-is a seat Apreferably conical in form and having a leak passage 332' of small area through which water can pass at all times. Back of this seat is a ball 34 adapted to close the seat except Jor the small by-pass. There is acover or cap behind the ball to keep it from gettingout of position but having a slot-35 adapted to permit the flow of water. On account of these conditions it will be understood that the chamber 31 on both sides of the diaphragm 30 is constantly full of water under pressure and that the diaphragm will move one way or the other according to changes in the pressure of the water.

Tn operation, as described above1 when the check valve 11 is released it boundsv wide open and remains there until the flow of water by it is stopped by the rising air pressure anda return wave is enacted. The valve 11 is liable to be slapped back to its seat before the drip chamber 16 has been lilled and the alarm sounded, or late enough to stop the alarm after it has started. The force required to open the auxiliary vcheck valve will overcome any resfstance in the chamber 31 because water can flow into it and out of it freely on both sides of the diaphragm when there is no pressure to close the valve 34. Therefore the-valve 17 will open easily due to pressure in the passages and 1G and the lever Q3 may swing' out to its imiting position, thus Hexingf the diaphrag'n'i inwardly toward the valve casing. llow in ease ol' a water hammer Caused as above described a sudden presfiure exerted would tend to close the valve 17 'guieldy and thus cause the trouble l have referred to. lint on ai'eount of the insistance which is caused bhv the atieinpt to tori-e the tube C32 invfarilly, the valve 34 will be rlosed bv the attempt ot' the Wa on the outer alle oli the diaphrqin to rash through the tube The prei-p.. '1 ot the water haelt of the valve 3l will force it to its seat. 'lhen only a verjvY small ouanlitv ot water will llovv out of the chamber 3l through the passage: Sf' and ntlv.

lil ani! the valve i7 rannot t'lose in* ln fact. it will lake coi .l rahletiine to close. generally lonffer than the vvrter l i This keeps ioninnnication 'from the main valve chan'ihei' to the and eauses the alarm to be soundedfconthe bail: pressure continues long onouojh the nier lasts.

open pipe f2!) tinuoualy and without intermission.

'valve 17 will be Caused to close After the valve ,it opens, the Water will be allowed to rush into the valve chamber with sloivlv.

suoli rapiditv that the pressure will be refr moved from the rear of the valve l.' and that will Close as rapidlvv as the valve flit- Will permit.

lt will he seen therefore that by this simple ai'i'anejeiaent the intermittent operation ot' the alarm Will be Converted into a Constant one and the alarm will operate Constantly Witlu'iut intermission until conditions become stabilized.

,filhouo'li l have illustrated and described only a single form of the invention I am aware of the taet thay i'iiodifieations can loe inade therein bvainy person slilled in the art without departing' troni the scope ol' the invention as expressed in the claims.

Therefore l do not 'i ish to be limited to allthe details herein disclosed but what I do claim im* i. The Combination with an alarm valve, ot an alarm, means for conducting Water vtroni said valve to said alarm, second means tor condus'tinn' vuiter to the aiarin. a second valve tor #losing the connection of said second means to the alarm, and means l'or retarding' thev losing ot the second valve.

The combination with an alarm valve, ot a bv-pass troni the niain thereofn ai i it ol the alarni. means leading :l'roni the se:

main valve to operate raid alarin, means leading' 'from the liv-pass to operate said alarm, a dil'erential Yalve .tor closing the connection ot' the laf-pass to raid alarm, the

s u'ond valve heno' yConsti'ueted and arrangffd to open under a lesser dilerenee in pressure than the main valve o1" the system, and means for retarding the closing' of the second valve.

3. The eonibiviation with an alarm valve and an alarm, of a by-pass from the high pressure side ot the main valve, a chamber connected with said by-pass, a tube in said eliainl fr, means for connecting; said tube to the alarm, said Chamber opening into the nia'n valve Chamber, a differential valve for closing' said ope iing' and 'Closingr the end ot' s; id tube, a lever connected with the second valve, means tor limiting the swingt of Said le\ ei' and therefore the opening ot the valve, and means for preventing the lever from moving* back rapidlyv to seat the valve after the valve is once opened.

The combination with an alarm valve having,y a groove in the valve seat connected with an alarni, ot a by-pass from the high pressure side ot' the main valve, a chamber conueeted with said bypass, a tube in said Chamber, means for connecting said tube to the alarm, said chamber opening into the main valve chamber, a dili'erential valve for Closingv sail` opening' and closingV the end of said tube, the last named valve having an area exposed to the water pressure in the main valve chamber materially larger than the area exposed to the pressure in the bypass chamber, the proportion being such that the second valve will open before the main Valve in ease ot' the lowering of the pressure in the valve easing, a lever connected with said valve, inc-ans for limitinga the swing of said lever and therefore the opening oi' the valve, and means for preventing the lever ""ronl moving bael rapidlyv to seat the Valve after the valve is once opened.

The eonibinatiani with an alarm valve casing' and valve, of a by-pass connected thereto` a Chamber Connected With tl e bypassy and having an opening into the interior ot' said valve easing', a tube in said elianiher eonneeted to eonduet water to an alarm deviife, a valve for Closing' said opening', said tube being in position for its end t0 be Closed by the valve when in closed position, a second chamber in open eonnnunication with the interior ot the valve easing, a diaphragm across the second chamber,V a tube Connected with said diaphragm and Connected Vith said alte. said tube being' Open to the interior ot said yeasingy to admit vvater into the second chamber behind the diaphragm. and a movable valve in the tube adapted to be closed by tht` pressure ol water troni the chamber behind the diail'ihrapjni toward the valve casino` to slow down the 'losing' ot the second Valve.

The combination with an alarm 'alve casing' and valve, ol a by-pass adjacent thereto, opening; Vinto the interior of said valve easing, a Yube Connected to c' nduct water to an altii'n'i device, a valve for Closing said opening', said tube being' in position for its end to be Closed by the valve when in Closed position. a second chamber in open coinn'iunieation with the interior of the valve easing, a diaphragm across the second chamber, a tube connected with said diaphragm and connected With said valve Jfor restricting the closing of the valve after it is opened, 5 said tube being open to admit Water into the second Chamber behind the diaphragm from the valve casing and having a valve seat provided with a leak passage, and a movable valve in the tube to be closed by the pressure of Water behind it in the 10 chamber.

1n testimony whereof I have hereunto aiixed my signature.

HJALMAR G. CARLSON.

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