US2871953A

US2871953A - Pendent sprinkler

Info

Publication number: US2871953A
Authority: US
Inventors: Bray Geddes Alan
Original assignee: Grinnell Corp
Current assignee: Grinnell Corp
Priority date: 1954-12-06
Filing date: 1956-06-15
Publication date: 1959-02-03
Anticipated expiration: 1976-02-03

Description

Feb.'3,'1959 I G. A. BRAY PENDENT SPRINKLER 5 sheets -sheet 1 Filed June 15, 1956 INVENTOR. GEDDES ALAN BRAY ATTORNEY Feb. 3, 1959 G. A. BRAY 2,

PENDENT SPRINKLER Filed June 15; 1956 s Sheets-Sheet 3 Jaw 510? INVE R.-

GEDDES ALAN BR FIG. 5

ATTORNEY United States Patent O PENDENT SPRINKLER Geddes Alan Bray, New Moston, Manchester, England assignor to Grinnell Corporation, Providence, R. 1., a corporation of Delaware Application June 15, 1956, Serial No. 591,579

8 Claims. (Cl. 169-37) 'This invention relates to automatic sprinkler systems of the so-called dry pipe type. More particularly it has to do with such systems in which a plurality of pipes carrying thermally actuated sprinkler heads at their lower ends have their upper ends connected to a supply or distributing pipe in spaced relation therealong and extending downwardly therefrom.

Some locations which are required to be served by fire extinguishing sprinkler systems are subject to low temperatures which would freeze the fire extinguishing medium (usually water) and render the system inoperative if the supply pipes distributed throughout the location were normally filled with this medium. To overcome this problem it has been customary to provide a valve at the source of supply of the medium, for example in a single heated room where the connection to a city water main emerges from the ground, which valve prevents the water from entering the distributing pipes until a fire occurs. Thus, a common arrangement is to fill the distributing pipes with air under pressure and provide a valve which this air pressure serves to keep closed. Then by thermal actuation the sprinkler heads open, the air is released through these open heads and the valve opens allowing water to flow into the distributing pipes to be discharged from the same open heads.

In most sprinkler systems the distributing pipes with which the sprinkler heads are associated extend horizontally throughout the location to be served, for example near the ceilings of enclosures, and it is frequently desirable or necessary to have some or all of the sprinkler heads mounted on the lower ends of lengths of generally vertical pipe (hereinafter called drop pipes) which have their upper ends connected to the horizontal pipes. This would be the arrangement, for example, where a false ceiling is employed through which only the sprinkler heads extend, the pipes above being concealed.

In such arrangements, however, if there is a fire or if water is introduced into the distributing pipes to test the system, while the water which would fill the horizontal pipes could be readily drained to reset the system after the fire is extinguished or the test concluded, any water which entered the unactuated sprinkler heads and downwardly extending drop pipes connecting the same to the horizontal pipes could only be drained by removing each such head.

To avoid such individual draining of each pendent sprinkler head, various arrangements have been proposed whereby the water is prevented from entering the drop pipes of unactuated sprinkler heads and whereby sprinkler head actuation permits such entry. For example, one

arrangement has been proposed having at the upper end of the drop pipe a valve, spring biased to open but normally latched closed by a direct mechanical connection extending to the unactuated sprinkler head. In another earlier arrangement a frangible member which normally closes the upper end of the drop pipe is shattered by a spring loaded plunger released by sprinkler head actuation.

Patented Feb. 3, 1959 The present invention has the advantage of employing a smaller number of parts than these previous proposals. Thus a dry pendent sprinkler is provided which in gen eral comprises a drop pipe sealingly closed at its lower end by the usual sprinkler head and sealingly closed at its upper end with a flexible diaphragm to form a chamber which is substantially filled with a non-freezing liquid. As long as the sprinkler head remains unactuated and sealingly closes the lower end of the drop pipe the diaphragm is supported against pressures in the distributing pipe by the incompressible non-freezing liquid and performs its closing function. When the sprinkler head is actuated, however, the lower end of the drop pipe is opened and the non-freezing liquid flows therefrom, the diaphragm is then no longer supported by the non-freezing liquid and the greater pressure in the horizontal pipe destroys the seal provided by the diaphragm.

Accordingly it is an object of this invention to provide a drop pipe of an automatic sprinkler system with improved seal means at its upper end which will assure the entry of a fire extinguishing medium into only those drop pipes whose sprinkler heads have been actuated.

Another object of this invention is to provide a seal for, and a non-freezing liquid in, a drop pipe of an automatic sprinkler system, the seal and liquid cooperating with each other to function as a one-way valve which prevents this non-freezing liquid from entering the system but which permits the passage of a fire extinguishing medium when the sprinkler head of that drop pipe is actuated.

Another object of this invention is to provide a drop pipe of an automatic sprinkler system with a seal and a non-freezing liquid, which liquid will support the seal against pressures in the system.

Another object of this invention is to provide a seal at the upper end of a drop pipe in an automatic sprinkler system which will prevent the mixing or difiusing of a non-freezing liquid in the drop pipe with water in the system.

Another object of this invention is to provide a seal means in a drop pipe for an automatic sprinkler system,

which seal means include a stud and a flexible diaphragm embracing the stud when the sprinkler head associated with the drop pipe is unactuated and which diaphragm will slide off the stud and open the seal means when the associated sprinkler head is actuated.

Another object of this invention is to provide an apertured flexible diaphragm which functions as a seal for a drop pipe in an automatic sprinkler system wherein the aperture is provided with an upstanding collar slidably fitting around a stud and wherein the portion of the diaphragm adjacent the collar normally has an upward slope.

Another object of this invention is .to provide an apertured flexible diaphragm which functions as a seal for a drop pipe in an automatic sprinkler system wherein the aperture fits around a stud and wherein substantial displacement of the diaphragm relative to the stud is neces-' ary to disrupt the seal.

In the drawings:

Figure 1 is an end elevation view of a drop pipe arrangement in accordance with the present invention with portions shown in cross section and with the diaphragm in sealing position;

Figure 2 is a side elevation view of the arrangement of Fig. 1;

Figure 3 is a cross section plan view taken on line 3-3 of Fig. 1;

Figure 4 is a cross section plan view taken of Fig. 1;

Figure 5 is fragmentary view like Fig. l, but showing the diaphragm in open position; and

Figure 6 is a perspective view of the diaphragm.

onsline 4-4 Referring now to the drawings, wherein like numerals denote like parts throughout, denotes a fitting in a supply or distributing pipe 11 which is normally filled with a gas (for example, air) under pressure. A threaded aperture 12 is provided in the fitting 10 into which is threaded a plug 14 having its own aperture 16. The top of the plug 14 is provided with a plurality of angularly spaced inclined legs 18 which terminate in a collar 20. A downwardly extending cylindrical stud 22 has its upper end secured within the collar by a pin 24.

A drop pipe 26 having a separable flange 28 at its upper end is secured to the plug 14 by a plurality of bolts 30 and nuts 31. A gasket may be placed between the fitting 10 and plug 14. At its lower end, this drop pipe is provided with a thermally actuated sprinkler head 32 which normally sealingly closes the lower end of the drop pipe but which, when actuated, opens this lower end. There are a number of sprinkler heads now on the market which may be used, inasmuch as this invention is independent of the particular type employed.

Clamped at its periphery between the plug 14 and the drop pipe flange 28 is an apertured impervious flexible sleeve or diaphragm 34. The periphery of the aperture is preferably provided with a lip portion 36 which slidably embraces a portion of the stud 22. A fluid 38, such as glycerine, having a freezing point below those temperatures normally encountered in nature and hereafter called the non-freezing liquid, substantially fills the chamber defined by the diaphragm, stud, drop pipe, and sprinkler head. For convenience in filling this chamber with the non-freezing fluid, the drop pipe flange 28 may be provided with a hole 40 and plug 42.

Such filling is done initially by assembling the unit comprising plug 14, flange 28, drop pipe 26 and sprinkler head 32 and disposing this unit on its side with the hole 40 uppermost. When filling is completed the plug 42 is threaded into place to close hole 40 and the unit is secured to the fitting 10 by threading the plug 14 into the aperture 12. In an automatic sprinkler system a plurality of such units are secured in the supply pipe 11 at spaced intervals whereby the pipe may supply a fire extinguishing medium to any drop pipe or pipes whose sprinkler heads have been actuated. The main part of the device may be hidden by a false ceiling 44, in which case an opening 45 is provided therein at each such device whereby the unit may be threaded into aperture 12 from below the false ceiling 44, for example with a special tool in the nature of a box wrench. A ceiling plate 45a serves to cover the opening 45 in such a false ceiling after the unit is installed.

The operation of the device is as follows:

If all of the sprinkler heads are unactuated, the gas (air) pressure in the fitting 10 will exert force against the diaphragm 34 tending to move the diaphragm off of the stud 22. If the chamber is completely filled with the non-freezing liquid, the diaphragm will not be so moved by this force because the liquid is substantially incompressible. If the non-freezing liquid does not completely fill the chamber there will be an air space S at the top of the liquid. Then the air pressure in the fitting 10 will cause the side portions of the diaphragm adjacent the lip 36 to collapse slightly about the stud 22 and as these portions collapse the space S diminishes in volume until the pressure of the air within space S equals the pressure in the fitting 10 and no further movement of the diaphragm can take place.

As shown in the drawings, the angle between the longitudinal axis of the stud 22 and the major portion of the diaphragm is substantially less than ninety degrees. If this angle were in the order of ninety degrees, the arrangement would have to be such that a slight displacement of the diaphragm would result in its sliding 01f the stud in order to make the device function. This would be undesirable if the air space S is present, the diaphragm must be able to move slightly, as noted, with- 4 out leaving the stud to make the pressure within S equal to the pressure in the fitting 14 If the sprinkler head 32 is actuated, it will open and the non-freezing liquid will flow from the drop pipe. Then the pressure within the chamber will drop below that of the air in the fitting 1.0. Then the air pressure in the fitting 10 will exert enough force to move the diaphragm off the stud 22 and the diaphragm will assume a configuration like that shown in Fig. 5. The air in the fitting 10 will now escape through the drop pipe and consequently the air pressure in the pipe 11 will drop. This will result in actuation of a valve (not shown) at a water supply station, and water will be admitted to the pipe 11. The water will then flow through the fitting 10 and down the drop pipe as indicated by the arrows in Fig. 5 and out of the sprinkler head.

After the fiow of water has ceased, as for example when the water How is stopped by a hand operated valve shut off when the fire is extinguished, the pipe 11 is drained of water, the device is reset by removing ceiling plate 45a, unthreading the unit from aperture 12, lowering the unit down through the ceiling opening 4-5, again locating the diaphragm on the stud, replacing the sprinkler head, refilling the chamber with glycerine, again threading the unit into aperture 12 through ceiling hole 45 and re placing the ceiling plate. Air under pressure is again introduced into the fitting 10, and the system is as it was before.

Assume now that some other sprinkler head or heads in another part of the system have been actuated and the fitting 10 is again filled with water. In this case, the pressure of the water, rather than the pressure of the air, will act against the diaphragm. However, the water in the fitting 10 will not enter the drop pipe nor will the non-freezing liquid in the drop pipe mix or diffuse into the water in the fitting 10. After the flow of water has ceased,.the fitting 10 is drained, the drop pipes whose Sprinkler heads were actuated are removed, reset and re placed as described, and air under pressure is again introduced into the fitting 10 and the system is as it was before.

It will be noted that, as shown in the drawings, the sides of the diaphragm snugly engage the interior of the aperture 16 of the plug 14. Thus if the fitting 10 is filled with water, due to the actuation of another head or heads in the system, and is subsequently drained, no substantial amounts of water (which might later freeze) will remain between the diaphragm and the walls of the aperture 16. In addition the clamped periphery of the sleeve or diaphragm 34 is situated only a slight distance below the interior surface of the fitting 10. It is desirable to make this distance small because when the fitting 10 is filled with water and subsequently drained, some water may remain between the diaphragm and interior of aperture 16. If a large amount of water could collect at this point, then if the ambient temperature should fall below the freezing point, the ice which would form might have a harmful eifect on the subsequent operation of the sleeve or diaphragm 34. Hence to keep the volume of the liquid which can collect in this space small, so that its effect can be neglected, the clamped periphery is preferably situated only a short distance below the interior of the fitting 10.

From the foregoing description and drawings, it will be apparent that the operation of the device is not dependent upon the particular arrangement of the diaphragm and stud shown in the drawings. Thus, the stud may be located entirely within the drop pipe or entirely within the fitting or it may extend into both. Similarly the stud may be secured to fixed structure at its end above the diaphragm or at its end below the diaphragm, or both.

I claim:

1. For a supply pipe carrying a fluid under pressure and having an aperture, a pendent device comprising: a drop pipe having one end adapted to be secured to the supply pipe at said aperture, an element at the said one end of the drop pipe having a portion movable between a first position in which said element prevents said fluid from passing therethrough and a second position in which said element allows said fluid to pass therethrough, closure means at the other end of the drop pipe, said drop pipe with the element and closure means at the ends thereof forming a closed chamber when said element portion is in said first position and said closure means is closed, and a non-freezing liquid substantially filling said chamber and supporting said element portion in said first position against the force exerted by said fluid under pressure when said closure means is closed, whereby opening of said closure means releases the liquid from the drop pipe and permits said fluid under pressure to move said element portion to said second position.

2. A device as set forth in claim 1 including a second element and wherein said first recited element cooperates with the second element to maintain the said element portion in said first position.

3. A device as set forth in claim 2 wherein said first recited element is an impervious flexible diaphragm having the said portion thereof provided with an aperture which receives said second element when said portion is in said first position.

4. A device as set forth in claim 3 wherein said second element is a stud and wherein said aperture is provided at its periphery with a lip, the sides of which are substantially parallel to and in engagement with said stud when said diaphragm portion is in said first position.

5. A device as set forth in claim 4 wherein said diaphragm portion adjacent said stud lies at an angle to the longitudinal axis thereof which is substantially less than 90 when said portion is in said first position.

6. In an automatic sprinkler system, in combination; a supply pipe having an aperture; a drop pipe having one end connected to the said supply pipe at the said aperture to form a junction therewith which permits the passage of a fluid from the supply pipe to the drop pipe through the aperture; an element disposed at said junction having a portion movable between a first position in which said element prevents the flow of a fluid from the said supply pipe to the said drop pipe and a second position in which said element allows the flow of a fluid from the said supment portion to assume its second position.

7. In combination, a supply pipe adapted to carry a fire extinguishing medium, said supply pipe having an aperture; a drop pipe assembly having one end connected to the said supply pipe at the said aperture to form a junction therewith which permits the passage of a fluid from the supply pipe to the drop pipe assembly through the aperture; an impervious flexible sleeve of larger diameter at one end than the other end; the periphery of the larger end of the sleeve being clamped around the said aperture between the said supply pipe and said one end of the drop pipe assembly; a cylindrical stud fixed relative to the said junction and having one end slidably receiving the smaller end of the said sleeve to close said aperture; an actuatable normally closed sprinkler head at the other end of the said drop pipe assembly, the sleeve, stud, drop pipe assembly and sprinkler head defining a closed chamber; a non-freezing liquid substantially filling the said chamber, whereby actuation of the sprinkler head allows the non-freezing liquid to flow out of the chamber and thus permit the smaller end of the sleeve to slide off the stud and hence allow a fluid in the supply pipe to flow into the drop pipe.

8. The combination of claim 7 wherein the said clamped portion of the sleeve is only slightly displaced I from the interior surface of the said supply pipe, whereby of its periphery and the interior surface of the supply pipe.

ply pipe to the said drop pipe; an actuatable sprinkler References Cited in the file of this patent UNITED STATES PATENTS 363,187 Tonge May .17, 1887 1,736,256 Doughty Nov. 19, 1929 2,903,150 Tyden Mar. 28, 1933 FOREIGN PATENTS 11,956 Great Britain Dec. 31, 1892