US3223171A

US3223171A - Fire sprinkler head closure plug

Info

Publication number: US3223171A
Authority: US
Inventors: Groot Walter R De; Lazerus Stanley
Original assignee: Atlantic Research Corp
Current assignee: Atlantic Research Corp
Priority date: 1964-01-09
Filing date: 1964-01-09
Publication date: 1965-12-14
Anticipated expiration: 1982-12-14

Description

Dec. 1965 w. R. DE GROOT ETAL 3,

FIRE SPRINKLER HEAD CLOSURE PLUG Filed Jan. 9, 1964 INVENTORS WALTER R. DE GROOT STANLEY LAZERU5 AGENT tributing water over a wide area.

United States Patent 3,223,171 FIRE SPRINKLER HEAD CLOSURE PLUG Walter R. De Groot, Arlington, and Stanley Lazerus,

Alexandria, Va., assignors to Atlantic Research Corporation, Fairfax, Va.,.a corporation of Virginia Filed Jan. 9, 1964,'Ser. No. 336,833 4 Claims. (Cl. 169-1) This invention relates to valves and, more particularly, to closure plugs for fire sprinkler heads.

Automatic fire sprinkler heads commonly employed in commercial establishments such as ofiice bulidings, warehouses, manufacturing plants, etc., include a threaded nipple which is received Within a boss provided in overhead water supply lines. Attached to the nipple or integrally formed therewith is a support means or bracket on the bottom of which is provided a spray plate for dis- A fusible member is inserted between the bracket and the nipple in such a manner as to obturate an orifice extending through the nipple and, thus, prevent water from flowing therethrough. Upon the application of heat above a predetermined temperature, such as will occur when a fire breaks out, a portion of the fusible member fuses and is released from engagement with the nipple and support bracket permitting 'water fiow through the nipple.

Current methods for stopping the flow of water through sprinkler heads are extremely expensive and relatively difficult and awkward to employ. The most common type of shut-off plug presently used is a wedge-shaped member which is inserted horizontally between the supporting bracket and the nipple. In addition to the high cost, installation of these plugs is difiicult as it requires the installer to climb up a ladder and hammer it in place while water is raining down. It also has been found that rapid insertion of the plug within a sprinkler head frequently damages the sprinkler head due to the large force required to wedge the plug properly into place, this force being applied parallel to and at a distance from the supporting means for the sprinkler head thus resulting in a relatively high moment at the juncture between the nipple and the boss.

In 'view of these disadvantages in currently available closure plugs it is an object of the present invention to provide an inexpensive closure plug which is relatively easy to install.

Another object of the present invention is to provide a closure plug which can be installed rapidly in a ceilingmounted sprinkler head by someone standing on the floor.

Further objects and attendant advantages of the present invention will become better understood from the fol- -lowing description.

tions. A resilient valving member is placed on one end of one ofthe telescoping members while an indentation is provided in the remote end of the other of the telescoping members. -A hole is provided in each of the telescoping members at such a location as to effect alignment of the holes when the telescoping members are in their contracted or shortened position. In this position a pin is placed through the holes to maintain the plug normally in the contracted position.

A closure plug formed in this manner is adapted for insertion within a fire sprinkler head of the type which includes a nipple and a support means extending from the nipple for supporting a spray plate mounted below the nipple. The support means also includes a small projection which extends upwardly toward the nipple and-which carries a fusible member. When the temperature in the immediate area of the sprinkler head exceeds a predetermined value a portion of the fusible member fuses-and the member falls from the sprinkler head exposing the projection. The closure plug is inserted in the sprinkler head by placing the indentation provided in'one end of the plug on the projection. Upon removal of the'pin, the spring-loaded telescoping members move in opposite directions causing the plug to expand and forcing the valve member upwardly against the nipple, obturating the orifice extending through the nipple and eliminating the flow of water therethrough.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention will-become better understood from the following description taken in combination with-the accompanying drawing in which:

FIGURE 1 illustrates a closure plug, formed in accordance with this invention, inserted Within a fire sprinkler head.

FIGURE 2 is a sectional view of a closure plug, formed in accordance with this invention, in its extended position.

FIGURE 3 is a partial sectional view of the closure plug of FIGURE 2 in its contracted position.

FIGURE 4 illustrates a pole used for inserting the closure plug in'a fire sprinkler head.

With reference to the-drawing, and more particularly FIGURE 1, there is shown a closure plug 10 inserted within a common fire sprinkler head 12 which in turn is mounted on a boss 14 provided on an overhead water supply line 16. The tire sprinkler head 12 includes an externally-threaded nipple 18 which is screwed intothe boss 14 and which hasan orifice (not shown) extending therethrough through which 'the water flows. The fire sprinkler head'12 also includes a support means or bracket 20 at the bottom of which is mounted a'spray plate 22 used for distributing the water emanating'from the orifice over a wide area. An upwardly extending projection :24 is also provided on the support bracket 20 to provide a support for a fusible member (not shown) Whiclris normally mounted in the sprinkler head to prevent flow of water therefrom. When the temperature in the imme diate area of the sprinkler head rises to a predetermined value a portion of the fusible member. fuses and the member falls from the sprinkler head thusexposing the orifice and permitting water to flow'from the sprinkler head.

The closure plug 10 used for stopping the flowof water, illustrated in FIGURE 2, includes a pair of'telescoping

members

26, 28, and resilient biasing means 30.for normally urging the telescoping members in opposedsdirections. The first telescoping member 26 is a tubular member, preferably cylindrical, and includes a resilient valve portion'or member 32, such as a rubber. cap,-mounted on one end thereof. The second telescoping member,:28 is. formed to slidingly fit within the first telescoping member 26 and has provided at the'end .29 thereof remote'from the'first telescoping member 26 a seat 33 having an indentation'34 centrally located in theouter surface. The second telescoping member 28 can be solid or it can'be tubular with or without an-end .wall on theend thereof which fits within the first telescoping member.

The resilient biasing means 30, for example, a'compression coil spring, is located within the first telescoping member 26 so as to abut against one end of the first telescoping member 26 and against the second telescoping member 28, normally urging the second member 28 in a direction effecting extension of the plug 10. Inorder to prevent the telescoping'membersizfi, 28 from separating, a groove is provided in-the internal surface of each telescoping member, the groove in the first telescoping mem her 26 being designated 35 and the groove in the second telescoping member 28 being designated 36. The

grooves

35, 36 are sufficiently deep and wide to receive and retain one turn of the coil spring 30. The upper surface of the second telescoping member 28 can be beveled as shown at 37 to simplify snapping the coil spring 30 in place.

A first hole 38 is provided through the wall of the first telescoping member 26 and a second hole 39 is provided through the second telescoping member 28. The

holes

38, 39 are so located such that they will be aligned when the plug is in its contracted or shortened position, as illustrated in FIGURE 3. Restraining means or a release pin 40 is inserted in the

holes

38, 39, so as to normally maintain the plug 10 in its contracted position. The release pin 40 need not extend completely through the telescoping members but need extend only so far as to maintain the plug in its contracted position. The contracted position can also be considered the loaded position since the coil spring" 30 is compressed and, thus, is exerting a force on the two

telescoping members

26, 28, tending to force them apart.

Insertion of the closure plug 10 within the fire sprinkler head 12 is achieved by placing the closure plug Within the fire sprinkler head such that the extension 24 of the support bracket 20 mates with the indentation 34 provided in the seat 33 of the second telescoping member 28. This arrangement will center the plug in the fire sprinkler head to facilitate proper operation thereof. The release pin 40 is then removed and the coil spring 30 forces the first telescoping member 26 away from the second telescoping member 28 and forces the resilient valve member 32 against the nipple 18 of the fire sprinkler head 12, thus obturating the orifice and eliminating the flow of water through the fire sprinkler head. In order to block the flow of Water through the orifice the spring 30 must have a compressive loading force when the plug is in its extended position at least equal to and preferably greater than the force exerted by water in the supply lines, whose pressure is usually in the range of 40 to 90 p.s.i.g. and could go as low as 20 p.s.i.g.

Because mounting of the plug merely requires placing it on the projection 24 of the fire sprinkler head and removing the release pin 40 this plug is easily adaptable to mounting from the floor through use of a mounting pole 42, illustrated in FIGURE 4. The mounting pole includes a pair of

resilient fingers

44, 46, and a triggering mechanism 48, such as a lever system or a string. The plug 10 is placed within the

fingers

44, 46, with the release pin 40 facing the pole 42. A hook 50 provided at the end of the triggering mechanism 48, is placed into a hole 52 provided in the end of the release pin 40. The operator then places the plug 10 in position in the fire sprinkler head and actuates the triggering mechanism 48 extracting the release pin 40 from the

telescoping members

26, 28. The spring 30 causes extension of the plug into position to eliminate the flow of water through the fire sprinkler head 12.

It can be seen that construction of the closure plug 10 is quite inexpensive since there need be no closely mated, accurately formed parts and, therefore, the tolerances of the various parts may be quite large. It is not important to maintain a close sliding fit between the

telescoping members

26, 28, because they contain no liquid or pressurized gas. Neither is it important that the cooperating

holes

38, 39, in the telescoping members be accurately formed for as long as the pin 40 can be inserted therethrough the spring will force the telescoping members apart until the walls of the telescoping members lock the pin in place. Therefore, one hole could be considerably larger than the other hole still allowing mounting of the pin in place While reducing the cost of production. The valve member 32 is constructed of a resilient material such as rubber and is formed considerably larger than the diameter of the orifice so that the plug will still obturate the orifice even if the plug is not accurately aligned on the projection 24. This also reduces the cost of production since the valve member need not accurately mate with the orifice.

While one specific embodiment has been shown and described above, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the invention in its broader aspects. Therefore, it is intended in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. For use in terminating flow through a fire sprinkler head of the type having a nipple in fluid-flow relationship with a fluid supply and a spray plate spaced from but attached to said nipple, a closure plug solely contained between said nipple and said spray plate with the extended length of said plug, when in use, being equal to the distance between said nipple and said spray plate, said plug comprising (a) a first member including a valve portion, said valve portion abutting and obturating said nipple and preventing fiuid flow through said nipple when said plug is in its extended position,

(b) a second member arranged in telescoping relationship with respect to said first member, said second member being adapted to engage said spray plate,

(c) spring means engaging said first and said second members and urging said first and said second members in opposed directions, and

(d) restraining means engaging said first and said second members for normally maintaining said plug in a contracted position, whereby disengagement of said restraining means permits said spring means to effect extension of said plug.

2. A closure plug as defined in claim 1 wherein said spring means is mounted within one of said members.

3. A closure plug as defined in claim 1 wherein said restraining means comprises a pin adapted to be received by a first hole provided in said first member and a second hole provided in said second member, said first and second holes being aligned when said plug is in said contracted position.

4. For use in terminating flow through a fire sprinkler head of the type having a nipple in fluid-flow relationship with a fluid supply and a spray plate spaced from but attached to said nipple, a closure plug solely contained between said nipple and said spray plate with the extended length of said plug, when in use, being equal to the distance between said nipple and said spray plate, said plug comprising,

(a) a first tubular member including a resilient valve portion, said valve portion being adapted to engage said nipple to prevent fluid flow therethrough,

(b) a second member arranged in telescoping relationship with said first tubular member, said second member having one end Wall having an indentation on the outer surface thereof adapted to receive a projection extending from a support means, said indentation being adapted to center said plug in said sprinkler head,

(c) a spring mounted within said first tubular member and engaging said first and second members urging said first and second members in opposed directions, and

(d) restraining means for normally maintaining said plug in a contracted position, said restraining means comprising a pin adapted to be receiving by a first hole in said first tubular member and a second hole in said second member, said first and second holes being aligned when said plug is in said contracted position whereby extraction of said pin permits said spring to effect extension of said plug.

(References on following page) 5 6 References Cited by the Examiner 2,520,588 8/1950 Wells et 211.

UNITED STATES PATENTS 2,607,429 8/ 1952 Schnorr 169-26 3/1908 G FOREIGN PATENTS ray.

6/1912 Morey 5 8,179 4/ 1912 Great Bntam. 1919 Sechrist 1 7 5 M. HENSON WOOD, 111., Primary Examiner. 7/ 1935 Bronander 169-26 EVERETT W. KIRBY, Examiner.

Claims

4. FOR USE IN TERMINATING FLOW THROUGH A FIRE SPRINKLER HEAD OF THE TYPE HAVING A NIPPLE IN FLUID-FLOW RELATIONSHIP WITH A FLUID SUPPLY AND A SPRAY PLATE SPACED FROM BUT ATTACHED TO SAID NIPPLE, A CLOSURE PLUG SOLELY CONTAINED BETWEEN SAID NIPPLE AND SAID SPRAY PLATE WITH THE EXTENEDED LENGTH OF SAID PLUG, WHEN IN USE, BEING EQUAL TO THE DISTANCE BETWEEN SAID NIPPLE AND SAID SPRAY PLATE, SAID PLUG COMPRISING, (A) A FIRST TUBULAR MEMBER INCLUDING A RESILIENT VALVE PORTION, SAID VALVE PORTION BEING ADAPTED TO ENGAGE SAID NIPPLE TO PREVENT FLUID FLOW THERETHROUGH, (B) A SECOND MEMBER ARRANGED IN TELESCOPING RELATIONSHIP WITH SAID FIRST TUBULAR MEMBER, SAID SECOND MEMBER HAVING ONE END WALL HAVING AN INDENTATION ON THE OUTER SURFACE THEREOF ADAPTED TO RECEIVE A PROJECTION EXTENDING FROM A SUPPORT MEANS, SAID INDENTATION BEING ADAPTED TO CENTER SAID PLUG IN SAID SPRINKLER HEAD, (C) A SPRING MOUNTED WITHIN SAID FIRST TUBULAR MEMBER AND ENGAGING SAID FIRST AND SECOND MEMBERS URGING SAID FIRST AND SECOND MEMBERS IN OPPOSED DIRECTIONS, AND (D) RESTRAINING MEANS FOR NORMALLY MAINTAINING SAID PLUG IN A CONTRACTED POSITION, SAD RESTRAINING MEANS COMPRISING A PIN ADAPTED TO BE RECEIVING BY A FIRST HOLE IN SAID FIRST TUBULAR MEMBER AND A SECOND HOLE IN SAID SECOND MEMBER, SAID FIRST AND SECOND HOLES BEING ALIGNED WHEN SAID PLUG IS IN SAID CONTRACTED POSITION WHEREBY EXTRACTION OF SAID PIN PERMITS SAID SPRING TO EFFECT EXTENSION OF SAID PLUG.