US3727695A

US3727695A - Sprinkler head protective cover

Info

Publication number: US3727695A
Application number: US00137398A
Authority: US
Inventors: B Danton
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-04-26
Filing date: 1971-04-26
Publication date: 1973-04-17
Anticipated expiration: 1990-04-17

Abstract

An apparatus for preventing tampering with automatic fire extinguisher sprinkler heads of the type which use a temperatureresponsive element for activating the sprinkler head when a predetermined temperature is reached. The apparatus comprises a collar which is attached to the sprinkler head, a cover which cooperates with the collar to completely enclose the temperatureresponsive element of the sprinkler head, and a plurality of struts which interconnect the cover and the collar. The struts are attached to the inner walls of the cover by fusible connectors which are adapted to fail at a predetermined temperature, thereby allowing the cover to separate from the collar. A spring member is interposed between the sprinkler head and the cover so that when the fusible connectors fail at a predetermined increase in temperature the cover will be ejected free of the sprinkler head.

Description

United States Patent 1 1 1 1 3,727,695

Danton 51 Apr. 17, 1973 SPRINKLER HEAD PROTECTIVE OTHER PUBLICATIONS COVER Filed:

Apr. 26, 1971 Appl. No.: 137,398

Catolog-Grobler Mfg. Co., Cleveland, 0. Fifth issue, 1936, FIG. 225, Page 122.

Primary Examiner--Robert S. Ward, Jr. AttorneyWhann & McManigal [57] ABSTRACT An apparatus for preventing tampering with automatic [52] US. Cl. ..l69/37, 169/42, 239/2885 511 1111, C1. ..A62c 37/12, A62c 37/20 fire emngusher spmkler heads the type. whfch [58] Field of Search I 169/26 37 38 40 a temperature-responsive element for activating the 42 4 sprinkler head when a predetermined temperature iS 2885, 600 602 reached. The apparatus comprises a collar which is at tached to the sprinkler head, a cover which [56] R feren Cimd cooperates with the collar to completely enclose the temperature-responsive element of the sprinkler head, UNITED STATES PATENTS and a plurality of struts which interconnect the cover 196,055 10/1877 Talcott ..239/288.5 and the collar- The Struts are attached to the inner 2,890,758 6/1959 Pfalzgmffet a1. ..179/37 walls of the cover by fusible connectors which are 1,230,469 6 1917 Esty ..l69/37 adapted to f il at a predetermined temperature, 3'393746 7/1968 f 169/42 x thereby allowing the cover to separate from the collar.

750,768 l/1904 H1bbard.... .....169/42 X 399 519 3/1889 Grime 169 [37 A spring member is interposed between the sprinkler 5:938 3/1394 head and the cover so that when the fusible connec- 750,767 1/1904 Hibbard ..169/40 tors fail at a predetermined increase in temperature 2,389,331 1 H1945 Tyden 169/37 the cover will be ejected free of the sprinkler head. 2,389,332 11/1945 Tyden ..l69/37 3,388,747 6/1968 Hodnett ..l69/42 X 8 Claim, 4 Drawing figures l *36 96 l "3e 22 Z we PATENTED APR 1 7 I915 3'. 727, 695

566754/14 A. DA N70/V INVENTOR.

WHANN 6 Ma MAN/GAL BY #Honmys for A J/mn/ SPRINKLER HEAD PROTECTIVE COVER BACKGROUND OF TH E IN VENTION 1. Field of the Invention This invention relates generally to automatic fire protection water sprinkler systems, and more particularly to an apparatus for protecting sprinkler heads the type which have temperature-responsive elements for activating the sprinkler head.

2. Description of the Prior Art In recent years there has been an ever-increasing amount of vandalism in schools and public buildings. A favorite target of they vandal is automatic fire protection systems. Of particular vulnerability is the automatic water sprinkler system which uses ceiling mounted pendant or hanger mounted upright sprinkler heads of the type which automatically discharge a stream of water when a temperature-responsive element, such as a fusible link embodied therein, reaches a predetermined temperature.

Typically, the vandal attaches a combustible material to one or more sprinkler heads, ignites the material,

and departs the scene. The heat generated by the burning material activates the sprinkler head, causing a deluge of water which can be stopped only be closing the main valve controlling the supply of water to the system. Frequently before the water flow can be stopped, extensive damage to furnishings, equipment, records, etc. has resulted. Additionally, since fire protection systems of the type described are often designed so that flow of water through the system will activate alarm devices, unnecessary and often dangerous evacuation of the building may also result. My invention is directed toward preventing this type of hazardous, disruptive, and damaging vandalism.

Prior art devices for protecting automatic sprinklers include the apparatus described in U.S. Pat. No. 3,388,747, to hodnett. Hodnett is directed toward apparatus for covering sprinkler heads located in clean rooms and the like rather than toward the prevention of tampering. The totally different construction of the Hodnett device makes it unsuitable to accomplish the objectives of my invention. In the Hodnett device the cover is threadably attached to the sprinkler head, and consequently, its unauthorized removal cannot be prevented. Further, the Hodnett apparatus cannot be installed without removing the sprinkler head, thereby temporarily disabling the system.

Other prior art devices in the field of the invention include the devices described in the patent to Hibbard, U.S. Pat. No. 922,40, and the patents to Grinnel, U.S. Pat. Nos. 399,519; 399,520; 399,521; 399,522; and 399,523. These devices, however, are quite dissimilar to my invention and will not accomplish the objectives thereof.

As will become apparent from the paragraphs which follow, the apparatus of my invention can be easily and simply connected to a sprinkler head without in any way disabling the system. Once in place, the apparatus completely protects the sprinkler head and cannot be removed by would be vandals.

SUMMARY OF THE INVENTION A sprinkler head cover apparatus for use in combination with fire protection water sprinkler heads which embody a temperature-responsive element for activating the sprinkler head at a predetermined temperature, comprising a collar attached to the sprinkler head, a protective cover adapted to cooperate with the collar to completely enclose the temperature-responsive element, and struts affixed to the cover by fusible connectors for holding the cover and the collar in juxtaposition so long as ambient temperatures remain below a predetermined level. A compression spring is provided within the cover to eject it from the proximity of the sprinkler head when the fusible connectors fail due to a predetermined increase in temperature.

It is an object of my invention to provide an apparatus for protecting sprinkler heads in which a collar affixed to the sprinkler head and a protective cover cooperate to enclose the temperature-responsive means of the sprinkler head, and in which the collar and the cover are held in juxtaposition only so long as ambient temperatures remain below a predetermined level.

Another object is to provide an apparatus of the type described in the preceding paragraph in which the collar and the cover are interconnected by a plurality of struts affixed to the inside of the cover by fusible connectors.

A further object is to provide an apparatus of the type described in which the connecting struts of the apparatus are of such a configuration that after they are affixed to the cover they will permit interconnection of the cover and the collar, but will prevent disconnection of the cover and the collar except at elevated temperatures.

A further object is to provide an apparatus of the type indicated in which a biasing means interposed between the cover and the sprinkler head urges the rapid separation of the cover from the sprinkler head when the fusible connectors of the connecting struts fail due to a predetermined increase in ambient temperature.

Still another object of my invention is to provide an apparatus of the type described in the previous paragraphs which may be easily and rapidly connected to a sprinkler head without the necessity for, in any way, disabling or disassembling the sprinkler head.

It is yet another object of my invention to provide an apparatus of the class described which can be inexpensively manufactured and can be installed with simple tools by unskilled workmen.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view partly in section of the apparatus of my invention shown connected to an automatic sprinkler head of typical construction.

FIG. 2 is an exploded view of the apparatus of my invention partly in section illustrating the various component parts of the apparatus.

FIG. 3 is a view along lines 33 of FIG. 1 showing the appearance of the apparatus as seen from above.

FIG. 4 is a view taken along lines 44 of FIG. 2 illustrating the locking tab arrangement of the split collar of the apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, FIG. 1 shows the apparatus of my invention connected toan automatic sprinkler head 12 of the type used in many schools and commercial buildings. Sprinkler head 12 has a butt portion 14 threadably connected to a fitting 16 which in turn is connected to a water supply pipe 18. For ornamental reasons an escutcheon, as indicated by numeral 20, surrounds the pipe fittings.

Automatic sprinkler heads of the type illustrated include closure means 22 which embodies a temperatureresponsive element such as the fusible link assembly designated generally by the numeral 23. When a predetermined temperature, generally around 165 F, is reached the fusible link will fail, allowing the closure means to open and water to discharge from the water supplypipe. The discharging water strikes deflector plate 24 and is dispersed over a wide area beneath the sprinkler head.

The structure described to this point forms no part of my invention, but serves to illustrate one type of fire protection sprinkler head which is amenable to combination with the apparatus of my invention. My invention may also be used with sprinkler heads of different configurations. It is important to note that, as will be explained hereinafter, the apparatus may be installed without dismantling or in any way disabling the fire protection system.

Referring to FIGS. 1, 3 and 4, the numeral 26 designates a collar means adapted to be connected to butt portion 14 of sprinkler head 12. As can best be seen in FIGS. 3 and 4, collar means 26 is comprised of two generally semicircular segments 26a and 26b which, when joined together, define a centrally located aperture 27. Segments 26a and 26b have means for interconnecting them, shown here as pairs of perpendicular disposed

interlockable tabs

28 and 30. As shown in FIG. 1, when collar 26 is in place around the sprinkler head,

tabs

28 and 30 extend downward in a direction away from water supply pipe 18.

In sprinkler heads of the class described, there exists a circumferential indentation or relief groove 31 located between the threaded and non-threaded portions of butt 14. In interconnecting collar 26 with sprinkler head 12, segments 26a and 26b are placed around sprinkler head butt portion 14 so as to seat into groove 31 with

tabs

28 and 30 extending downwardly. As can be seen in FIG. 1, central aperture 27 formed by the joining of segments 26a and 26b is ofa diameter slightly greater than the outside diameter of relief groove 31 but smaller than the pitch diameter of the threads on butt portion 14. Groove 31 therefore serves to lock collar 26 against vertical movement relative to butt portion 14. With segments 26a and 26b supported in mating alignment and resting in groove 3], the outward extremity of one tab 30, designated as 30a in FIG. 4, is bent around its mating tab 28 so as to interlock the tabs in the manner illustrated. The operation is then repeated relative to the second pair of

tabs

28 and 30. In this way, the generally circular collar 26, as illustrated in FIG. 3, is formed and, because ofthe relative diameters of aperture 27 and groove 31, is held captive on the sprinkler head in the position shown in FIG. 1.

As can be seen in FIG. I, collar 26 in cooperation with a generally cup-shaped protective cover 32 serve to completely surround and protect temperatureresponsive element 23 of sprinkler head 12. The cuplike shape of the cover is desirable in that it is both decorative and functional and can be easily cleaned. Other shapes, however, may be used if desired for functional or decorative reasons. A small hold 33 is provided at the bottom of cover 32 to allow drainage of water which may form within the cover due to condensation.

Heat releasable means for interconnecting cover 32 and collar 26 is shown as comprising a plurality of elongated struts 34 attached to the interior walls of cover 32 by fusible connector means such as fusible rivets 36.

I have found that the use of three struts spaced equally around cover 32 is satisfactory for interconnecting cover 32 and collar 26, although a different number may be used. The means for connecting struts 34 to cover 32 must be fusible in order that separation of the cover and the struts will occur at a predetermined temperature in a manner which will be discussed in greater detail hereinafter in the section entitled Operation."

As can be seen in FIGS. 1 and 2, the ends of struts 34 located proximate the open end of cover 32 are cut and bent so as to define a plurality of inwardly protruding prongs or fingers 38. As can best be seen in FIG. 1, when the inside diameter of cover 32 is reduced by the thickness of struts 34, the resulting diameter is slightly greater than the outside diameter of collar 26. However, when the inside diameter of cover 32 is further reduced by the amount that fingers 38 protrude inwardly, the resulting inside diameter becomes less than the outside diameter of collar 26. It follows, therefore, that during assembly of the apparatus when cover 32 carrying struts 34 is placed over sprinkler head 12 and collar 26 affixed thereto, fingers 38 will engage the lower periphery of collar 26, impeding further upward movement. Because of the shape and yieldable nature of fingers 38, however, increased upward pressure on cover 32 will cause fingers 38 to tend to conform to the plane of struts 34, thus allowing upward passage of cover 32. At the point when the lower extremities of fingers 38 pass the upper periphery of collar 26, they will spring outwardly resuming their original orientation. In this position, fingers 38 will rest upon the upper surface of collar 26, and because of their shape, will block any attempt to move cover 32 downwardly.

It is to be observed that as cover 32 is moved upwardly over sprinkler head 12, a biasing means, shown here as a compression spring 40 housed within cover 32, engages the lower surface of deflector plate 24. Continued upward movement of cover 32 will compress spring 40 to a configuration as illustrated in FIG. 1. In this configuration spring 40 is continuously urging the separation of cover 32 and collar 26 against the re sistance of fingers 38 of struts 34.

When the device of applicants invention has been positioned over the sprinkler head in the manner described in the previous paragraphs and as illustrated in FIG. I, it can be seen that temperature-sensing element 23 of sprinkler head 12 is totally enclosed within the space defined by the internal surfaces of cover 32 and collar 26. This enclosure of the temperaturesensing element precludes tampering or vandalism, and prevents malicious activation of the sprinkler head.

Although my invention has been described in the previous paragraphs relative to pendantly mounted sprinkler heads, it is to be appreciated that the apparatus of my invention may also be used with upright sprinkler heads.

OPERATION and 26b together, thus forming collar 26. As previously is explained, due to the relative diameters of aperture 27 and groove 31, collar 26 is now locked against vertical movement relative to butt portion 14. Nest, the user places spring 40 inside cover 32 and urges the cover over the sprinkler head. When fingers 38 engage the 20 lower edges of collar 26, slight additional pressure will cause them to flatten and pass by the outer edges of collar 26 where they will then snap outwardly to a position as shown in FIG. 1. ln this position, fingers 38 rest against the top of collar 26 and effectively prevent 5 removal of the cover.

Sprinkler head 12 is now effectively sealed against insertion of any type of foreign material and the temperature-responsive means 23 protected against tampering.

In the event of a fire causing temperatures in proximity of the sprinkler head to reach approximately 145F., rivets 36 will fail, allowing separation of struts 34 from cover 32. Spring 40 which is under compression, as shown in FIG. 1, will then cause cover 32 to be ejected free of the sprinkler head, thus exposing temperature-responsive element 23. When temperatures reach approximately l65F., he sprinkler head will be activated in its normal manner and will operate exactly as it would have had my apparatus not been connected to it.

lclaim:

1. An apparatus for protecting automatic fire extinguisher sprinkler heads, said apparatus being adapted for use in combination with a water distribution means including automatic fire extinguisher sprinkler heads having temperature responsive means adapted to activate a closure valve to permit discharge of water through the sprinkler head when a predetermined elevated temperature is reached, said apparatus comprising:

a. connector means for interconnection with the water distribution means at a location proximate a previously installed sprinkler head, said connector means being adapted to be connected to the water distribution means without disconnecting or disassembling the distribution means or the sprinkler head;

b. a protective cover adapted to cooperate with said connector means to enclose the temperature responsive means of the sprinkler head. and

c. coupling means for operatively coupling together said connector means and said protective cover, said coupling means comprising at least one structural element so constructed and arranged as to permit coupling together of the aforementioned members at ambient temperature by non-rotative substantially axial movement of said cover relative to said connector means but so constructed and arranged as to permit decoupling of the members only at a predetermined elevated temperature.

2. An apparatus as defined in claim 1, including a biasing means for urging separation of said protective cover and said connector means.

3. The apparatus as defined in claim 1 in which said connector means is adapted to be secured to a butt portion of an operatively installed sprinkler head proximate the point at which said sprinkler head is connected to the water distribution means, and in which said connector means comprises first and second generally semicircular portions and means for interconnecting said semicircular portions when said connector means is in an operative position relative to an installed sprinkler head.

4. The apparatus as defined in claim 1 in which said coupling means includes fusible means adapted to fail at an elevated temperature below that at which the temperature-responsive element of the fire sprinkler head is designed to actuate the closure valve.

5. An apparatus for protecting automatic fire extinguisher sprinkler heads, said apparatus being adapted for use in combination with an automatic fire extin guisher sprinkler head which has a temperatureresponsive means adapted to activate a closure valve to permit discharge of water through the sprinkler head when a predetermined elevated temperature is reached, said apparatus comprising:

a. a collar means adapted to be attached to the sprinkler head;

b. a protective cover adapted to cooperate with said collar means to enclose the temperature-responsive means of the sprinkler head; and

0. means for holding said collar means and said protective cover in juxtaposition so long as ambient temperatures remain below a predetermined temperature level said means comprising a plurality of struts interconnecting said protective cover and said collar means.

6. The apparatus as defined in claim 5 in which said struts are secured to said protective cover by connecting means fusible at a predetermined temperature and in which said struts have means for engaging said collar means.

7. The apparatus as defined in claim 5 in which said connecting means are rivets constructed of a material fusible at a predetermined temperature.

8. An apparatus for protecting automatic fire extinguisher sprinkler heads, said apparatus being adapted for use in combination with an automatic fire extinguisher sprinkler of the type used in tire protection systems which has a temperature-responsive means adapted to activate a closure valve to permit discharge of water through the sprinkler head when a predetermined elevated temperature is reached, said apparatus comprising:

a. a collar means adapted to be attached to a sprinkler head while the sprinkler is operatively installed in place in a tire protection system without requiring the disassembly of the sprinkler head or its disconnection from the fire protection system;

b. a protective cover adapted to cooperate with said collar means to enclose the temperature-responsive means of the sprinkler head;

. biasing means for urging separation of said cover and said sprinkler head when said cover is in juxtaposition with the sprinkler head; and

. heat releasable means for interconnecting said cover and said collar, said means having yieldable cover engaging elements and being constructed so 1 prevented so long as ambient temperatures remain below a predetermined level. v

Claims

1. An apparatus for protecting automatic fire extinguisher sprinkler heads, said apparatus being adapted for use in combination with a water distribution means including automatic fire extinguisher sprinkler heads having temperature responsive means adapted to activate a closure valve to permit discharge of water through the sprinkler head when a predetermined elevated temperature is reached, said apparatus comprising: a. connector means for interconnection with the water distribution means at a location proximate a previously installed sprinkler head, said connector means being adapted to be connected to the water distribution means without disconnecting or disassembling the distribution means or the sprinkler head; b. a protective cover adapted to cooperate with said connector means to enclose the temperature responsive means of the sprinkler head, and c. coupling means for operatively coupling together said connector means and said protective cover, said coupling means comprising at least one structural element so constructed and arranged as to permit coupling together of the aforementioned members at ambient temperature by non-rotative substantially axial movement of said cover relative to said connector means but so constructed and arranged as to permit decoupling of the members only at a predetermined elevated temperature.

5. An apparatus for protecting automatic fire extinguisher sprinkler heads, said apparatus being adapted for use in combination with an automatic fire extinguisher sprinkler head which has a temperature-responsive means adapted to activate a closure valve to permit discharge of water through the sprinkler head when a predetermined elevated temperature is reached, said apparatus comprising: a. a collar means adapted to be attached to the sprinkler head; b. a protective cover adapted to cooperate with said collar means to enclose the temperature-responsive means of the sprinkler head; and c. means for holding said collar means and said protective cover in juxtaposition so long as ambient temperatures remain below a predetermined temperature level said means comprising a plurality of struts interconnecting said protective cover and said collar means.

8. An apparatus for protecting automatic fire extinguisher sprinkler heads, said apparatus being adapted for use in combination with an automatic fire extinguisher sprinkler of the type used in fire protection systems which has a temperature-responsive means adapted to activate a closure valve to permit discharge of water through the sprinkler head when a predetermined elevated temperature is reached, said apparatus comprising: a. a collar means adapted to be attached to a sprinkler head while the sprinkler is operatively installed in place in a fire protection system without requiring the disassembly of the sprinkler head or its disconnection from the fire protection system; b. a protective cover adapted to cooperate with said collar means to enclose the temperature-responsive means of the sprinkler head; c. biasing means for urging separation of said cover and said sprinkler head when said cover is in juxtaposition with the sprinkler head; and d. heat releasable means for interconnecting said cover and said collar, said means having yieldable cover engaging elements and being constructed so that, as said protective cover is placed over the sprinkler head and moved into juxtaposition with said collar means against the urging of said biasing means, interconnection of said cover and said collar means is permitted, but disconnection is prevented so long as ambient temperatures remain below a predetermined level.