US3705691A

US3705691A - Discharge head utilizing a pressure-responsive detent mechanism

Info

Publication number: US3705691A
Authority: US
Inventors: Karol R Zenker
Original assignee: Factory Mutual Research Corp
Current assignee: Factory Mutual Research Corp
Priority date: 1971-09-08
Filing date: 1971-09-08
Publication date: 1972-12-12
Anticipated expiration: 1989-12-12
Also published as: DE2243992B2; JPS4836998A; GB1395174A; DE2243992A1; DE2243992C3; JPS5128959B2

Abstract

A pressure responsive discharge head wherein the expellable plug is disposed in the outlet of a body member having an inlet adapted for connection to a source of fluid under pressure, with the plug being connected relative to the body member by means of a detent mechanism. Upon a predetermined temperature being attained in the vicinity of the head, as well as a predetermined pressure existing in the body member, the connection provided by the detent mechanism is broken and the plug is released from the outlet to permit the fluid to be discharged from the nozzle.

Description

United States Patent Zenker [451 Dec. 12,1972

[54] DISCHARGE HEAD UTILIZING A PRESSURE-RESPONSIVE DETENT MECHANISM [72] lnventor: Karol R. Zenker, Needham,Mass.

[73] Assignee: Factory Mutual Research Corporation, Norwood, Mass.

22 Filed: Sept. 8, 1971 21] Appl.No.:178,734

[52] US. Cl. ..239/452, 137/70, 169/37 [51] .Int. Cl. ..B05b 1/32 [58] Field of Search ..239/452, 456, 534; 169/37,

[56] References Cited UNITED STATES PATENTS 2,414,127 1/1947 Shaw ..l69/38 3,288,224 11/1966 Trudeau ..l69/42X 3,289,686 12/1966 Tyer,Jr. ..169/42X 3,655,136 4/1972 Livington ..l69/37X Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-Michael Y. Mar Attorney-Joseph M. Lane et a1.

[5 7] ABSTRACT A pressure responsive discharge head wherein the expellable plug is disposed in the outlet of a body member having an inlet adapted for connection to a source of fluid under pressure, with the plug being connected relative to the body member by means of a detent mechanism. Upon a predetermined temperature being attained in the vicinity of the head, as well as a predetermined pressure existing in the body member, the connection provided by the detent mechanism is broken and the plug is released from the outlet to permit the fluid to be discharged from the nozzle.

14 Claims, 2 Drawing Figures PAIENTEDuEm m2 3.705.691

FIG].

INVENTOR KAROL R. ZENKER WM @W A ORNEYS 1 DISCHARGE HEAD UTILIZING A PRESSURE- RESPONSIVE DETENT MECHANISM BACKGROUND OF THE INVENTION The fire fighting capability of typical prior art fire protection systems employing a number of sprinkler heads mounted in an elevated position in the enclosure to be protected is often curtailed when the system is in-- stalled in relatively large storage facilities, such as warehouses, etc. One of the reasons for this is due to the fact that these large storage enclosures often contain very high stacks of combustible materials which frequently are highly inflammable. As a result, upon the development of fire in the enclosure, fire plumes or columns of feet'and higher may flare out beneath the ceiling of the enclosure and actuate numerous sprinkler heads located at such a distance from the fire that they are ineffective to deliver water or other extinguishant to the surfaces of the combustible materials. This contributes not only to redundant and flooding use of the water, but, more significantly, robs water from the heads over the fire where it is needed to extinguish the fire.

In. US. Pat. application Ser. No. 72,333, filed on Sept. 15, 1970, now Pat. No. 3,653,444 by the same inventor and assigned to the same assignee as the present application, a fixed fire extinguishing system is disclosed which is designed to limit the number of sprinkler heads which will be activated by a fire. The heads are spaced apart greater distances and have large outlet orifices to enable greater quantities of water or other extinguishant to be delivered from each head at lower flow rates. Preferably, the heads are in the form of wide angle spray nozzles which develop a downwardly directed spray having large size droplets as compared to the droplets produced by the conventional sprinkler heads.

With this arrangement, the first nozzle actuated by the fire has a much better possibility of extinguishing the fire, because of the ability to retain a predetermined discharge density and the increased ability of the larger droplets to penetrate the fire plume of a high challenge fire. If the heat of the fire spreads, additional nozzles are actuated to help the first nozzle fight the fire and to wet down areas surrounding the fire to provide exposure protection to inhibit the spread of the tire. However, the additional nozzles which are allowed to be actuated are limited to a small predetermined number to avoid the prior art problems created by two many heads being actuated; namely, interfering with the fire fighting capabilities of those nozzles positioned immediately above the fire and over the area immediately surrounding the fire by reducing the discharge density, and causing unnecessary water damage by allowing an excessive number of nozzles to be actuated at points remote from the fire. In accordance with a preferred embodiment of the abovementioned application, the above is achieved by establishing a pressure floor so that a minimum pressure must exist at each nozzle before it will open. The system is designed so that this minimum pressure will not be reached until a predetermined number of nozzles have been opened.

Although this embodiment results in several advantages including increased fire fighting capability and significant cost savings in several respects, it suffers from one disadvantage. Specifically, in establishing the above-mentioned pressure floor, an expellable plug normally blocks the outlet of the nozzle and is adapted to be expelled from the nozzle to permit extinguishant flow therethrough upon the fusing of a conventional temperature responsive device and the presence of a fluid pressure in the nozzles of a magnitude exceeding a predetermined value. In establishing the latter value, a helical compression spring is utilized to latch the expellable plug in a closed position. The design is such that the extinguishant pressure in the nozzle acts upon the helical spring and must be of a value to overcome the force of the spring before the expellable plug can be released. However, it has been discovered that the use of the above-mentioned spring makes it extremely difficult to ascertain the precise pressure required to overcome the force of the spring. This is largely due to the fact that it is extremely difficult to obtain a compression spring that will achieve a predictable result at a cost compatible with this type system. It can be appreciated that this renders the overall design and operation of the system extremely unpredictable.

SUMMARY OF THE INVENTION It is therefore an object of the invention to provide a pressure floor system of the above type which eliminates the use of a compression spring, and which enables the plug from the nozzle to be expelled in response to a precise predetermined finite fluid pressure occurring in the nozzle.

Towards the fulfillment of this object, the nozzle of the present invention comprises a body member having an inlet for a source of fluid under pressure, an outlet for discharging said fluid, plug means disposed in said outlet, and detent means for locking said plug means relative to said body member and responsive to a predetermined fluid pressure in said body member for releasing the plug means from the body member to permit expulsion of the plug means from the outlet.

BRIEF DESCRIPTION OF THE DRAWINGS Reference is now made to the accompanying drawings for a better understanding of the nature and objects of the present invention.'The drawings illustrate the best mode presently contemplated for carrying out the objects of the invention and are not to be construed as restrictions or limitations on its scope. In the drawings:

FIG. 1 is a vertical crosssectional view of the nozzle of the present invention; and

FIG. 2 is an enlarged partial view similar to FIG. 1 and showing a detail of the nozzle of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The nozzle of the present invention will be described by way of example in connection with a fixed fire extinguishing system, wherein the nozzle is adapted for receiving and discharging a tire extinguishant in response to information received from a fire occurring in a particular structure in which the nozzle is mounted. Referring to FIGS. 1 and 2, the nozzle is shown in general by the reference numeral 10 and comprises a cylindrical body 12 having an upper end portion which is internally threaded as shown at 14 for connection to a source of extinguishant, such as water, and a lower end portion which defines an outlet orifice 16 of 'a reduced crosssection. A pair of

spiral vanes

18a and 18b are fixed within the body 12 for imparting a swirling motion to the water flowing downwardly therethrough in a conventional manner. The

vanes

18a and 18b support a hollow central hub 20 which, in turn, slidably supports a rod 22 having a plug member 24 fixed on its lower end and extending in the outlet orifice 16. A sealing ring 26 is positioned about the periphery of the plug member 24 and sealingly engages the inner wall of the body 12 near the outlet orifice 16.

The rod 22 is latched in the position shown in FIG. 1 by a rod 32 which extends slidably through an externally threaded boss .34 projecting from the side of the body 12. One end of the rod 32 extends through the vanc 18b and the wall of the central hub 20 into a tapered hole 36 in the rod 22 to latch it in the position shown.

A sleeve 38 is threaded on the end of the boss 34. The outer end of the sleeve is closed off by an externally threaded stub shaft 40 having a ring or yoke 42 thereon. The rod 32 slidably extends through the stub shaft 40, and the other end of the rod engages a conventional fusible link assembly 44 positioned within the ring 42. The assembly 44 prevents movement of the rod 32 to the'right as viewed in FIG. 1, until the head of a fire fuses a portion of the assembly and causes it to collapse. Since the assembly 44 is the standard type commonly used in conventional sprinkler heads now on the market, it will not be described in greater detail.

The rod 32 has a piston head 46 mounted thereon which slidably engages the internal wall of the sleeve 38. A spring 48 is positioned between the boss 34 and the piston head 46 to bias the piston head and the rod 32 to the right with a predetermined biasing force.

With this arrangement, the piston head 46 and the rod 32 will be driven to the right under the action of the spring 48, upon the link assembly 44 collapsing in response to the heat of the fire and thus unlatch the rod 22.

A detent mechanism is provided for locking the rod 22, and therefore the plug member 24, in the position of FIG. 1. This detent mechanism is better depicted in FIG. '2, and comprises a sleeve 56 disposed on the upper portions of the

vanes

18a and 18b, and having a reduced portion 56a which extends into a counterbore formed in the upper end portion of the hub 20. A set screw 58 extends through the latter upper end portion and engages in a channel formed in the reduced portion 56a of the sleeve 56 to secure the latter in a concentric position within the hub 20. The hollow portion of the sleeve 56 receives the upper end portion of the rod 22 with a slight clearance being provided to permit movement of the rod relative to the sleeve.

A plurality of spring-loaded balls 60 are supported by the sleeve 56 and engage the rod 22. A preferred embodiment would utilize four such balls spaced at 90 intervals, and since the balls and their supporting structure are identical, only two are shown and one described in detail, for the convenience of preparation.

In particular, the ball 60 is supported in one end of a radial bore 62 formed through the sleeve 56, and a high-compression spring 64 is disposed in the bore 62 and urges the ball outwardly from the end of the bore, with a tapered shoulder 62a being formed at the end of the bore to prevent complete discharge of the ball from the bore. A ball 66 is supported in the outer end of the bore 62 and slidably engages the walls thereof so .that its position in the bore can be adjusted in order to vary the compressive load on the spring. One portion of the ball 66 projects from the end of the bore 62, and another diammetrically opposite portion is engaged by an appropriately formed end of the spring 64 to center the latter in the bore 62.

A continuous groove 69 is formed around the cir-.

cumference of the rod 22 near the upper end thereof in alignment with the ball 60. In this manner, the spring 64 urges a portion of the ball 60 into the groove 69 to lock the rod 22 relative to the body member 12, with the magnitude of the locking force being determined on all position of the ball 66 in the bore 62 and the resultant compression of the spring 64.

A cap 70 extends over the sleeve 56 and has an externally threaded plug portion 72 which engages corresponding threads formed in the upper portion of the bore in the sleeve 56. The internal wall of the cap 70 has a tapered inner surface 74 which engages the ball 66. As a result, rotation of the cap 70 will cause it to move axially relative to the sleeve 56 and cause a corresponding variation in the amount of camming force applied to the ball 66 by the tapered inner surface 74. This, in turn, regulates the load on the spring 64 and the locking force applied to the rod 22 by the ball 60.

Since the sleeve 56 and the cap 70 are both concentrically aligned relative to the rod 22, the load on each ball 60 can be regulated to an exact degree in order to precisely adjust the amount of force required to release the rod 22 and therefore the plug member 24 from the detent mechanism.

In operation, the nozzles 10 of the entire fire protection system are installed at an elevated position in the structure to'be protected in the condition shown in FIGS. 1 and 2, i.e., with each nozzle having its rod 32 extending in the tapered hole 36 of the rod 22, with the balls 60 extending in the groove 69 formed in the rod 22, and with the cap 70 adjusted to a predetermined position relative to the sleeve 56 to control the compression of the spring 64 and therefore the load on the balls 60.

If the fusible link assembly 44 is thermally actuated in response to an elevated temperature in its vicinity, the tension of the spring 48 causes the rod 32 to release the rod 22. The extinguishant pressure in the body member 12 acting on the inner end face of the plug member 24 forces it downwardly as viewed in HO. 1, in direct proportion to the amount of pressure. If the force acting on the plug member 24 as a result of this pressure exceeds the locking force applied to the rod 22 by the spring-loaded balls 60, the rod 22 will be released, and it, along with the plug member 24, will discharge outwardly from the body member 12 under the force of the extinguishant Pressure. Of course, if the extinguishant pressure is not sufficient to overcome the locking force provided by the spring-loaded balls 60, the plug member 24 will not be expelled from the body portion 12 despite the collapse of the fusible link assembly 44.

ln this manner, the number of nozzles that are actuated will be limited by the extinguishant pressure available, and the fire fighting capability of those nozzles positioned immediately above the fire and over the area immediately surrounding the fire will not be curtailed. Also, the unnecessary water damage resulting from an excessive number of nozzles being actuated at points remote from the fire will be eliminated, as discussed above.

It can be appreciated that several variations may be made in the foregoing with departing from the scope of the invention. For example, the number of springloaded balls 60, and corresponding structure, can be varied in accordance with particular design requirements. Of course, still other variations of the specific construction and arrangement of the nozzle disclosed above can be made by those skilled in the art without departing from the invention as defined in the appended claims.

lclaim:

l. A discharge head comprising a body member having an inlet for a source of fluid under pressure, an outlet for discharging said fluid, plug means disposed .in said body member for preventing the discharge of fluid from said outlet, and detent means for locking said plug means relative to said body member, said detent means being adapted to release said plug means from said body member in response to a predetermined fluid pressure in said body member to permit the discharge of fluid from said outlet.

2. The head of claim 1 wherein said detent means is in the form of at least one spring-loaded locking element supported by one of said members and engaging the other of said members.

' 3. The head of claim 2 further comprising adjusting means for adjusting the load on said locking element to vary said predetermined fluid pressure.

4. The head of claim 3 wherein said plug means comprises a rod portion and a head portion, said locking element being in the form of a ball having a portion extending in a groove formed in said rod portion.

5. The head of claim 4 wherein said adjusting means comprises a sleeve mounted in said body member in a concentric relationship with said rod portion and adapted to receive an end portion of said rod portion, said sleeve having a bore formed in the wall thereof for receiving said ball and the spring for said ball, said bore being aligned with said groove in the locking position of said detent means.

6. The head of claim 5 wherein said adjusting means further comprises a cam follower slidably supported in said bore and engaging said spring, and camming means engaging said cam follower and adapted to vary the position of said cam follower in said bore to vary the resulting compression of said spring and the resulting load on said ball.

7. The head of claim 6 wherein said adjusting means further comprises a cap concentrically disposed relative to said sleeve and in threaded engagement therewith, an inner wall of said cap having a tapered surface which engages said cam follower and forms said camming means, whereby rotation of said cap varies the position of the cam follower in said bore.

8. The head of claim 7 wherein a plurality of said balls are supported by said body member and engage said plug means, whereby rotation of said cap effects a uniform variation in the load on said balls.

9. The head of claim 1 further comprising latching means for retaining said plug means in said body member and means responsive to a predetermined temperature in the vicinity of said head for releasing said latching means.

10. The head of claim 1 wherein said detent means comprises locking means mounted relative to said body member and engaging said plug means, and camming means engaging. said locking means for applying a force to said plug means to lock said plug means relative to said body member.

11. The head of claim 10 wherein. said camming means comprises a cap in threaded engagement with saidbody member, said cap having a tapered surface for engaging said locking means, whereby rotation of said cap varies the relative position between said tapered surface and said locking means to adjust said force and vary said predetermined pressure.

12. The head of claim 11 wherein said locking means comprises a plurality of locking members spaced around said plug means and in engagement therewith, and a spring extending between each locking member and said tapered surface, wherein said rotation of said cap uniformly varies the force applied to said plug means by each locking member.

13. A discharge head comprising a body member having an inlet for a source of fluid under pressure, an outlet for discharging said fluid, plug means disposed in said body member for preventing the discharge of fluid from said outlet, at least one locking member supported by said body member and engaging said plug means, a camming member threadably engaging said body member and defining a camming surface, and a cam follower engaging said camming surface and said locking member for urging said locking member into engagement with said plug means to apply a predetermined force to said locking member and lock said plug means relative to said body member in the absence of a fluid pressure in said body member of a value that overcomes said force, whereby rotation of said camming member varies the force applied to said plug means by said locking member.

14. The head of claim 13 wherein there are a plurality of locking members spaced around said plug means in engagement therewith, said rotation of said camming member uniformly varying the force applied to said plug means by said locking members.

Claims

1. A discharge head comprising a body member having an inlet for a source of fluid under pressure, an outlet for discharging said fluid, plug means disposed in said body member for preventing the discharge of fluid from said outlet, and detent means for locking said plug means relative to said body member, said detent means being adapted to release said plug means from said body member in response to a predetermined fluid pressure in said body member to permit the discharge of fluid from said outlet.

3. The head of claim 2 further comPrising adjusting means for adjusting the load on said locking element to vary said predetermined fluid pressure.

10. The head of claim 1 wherein said detent means comprises locking means mounted relative to said body member and engaging said plug means, and camming means engaging said locking means for applying a force to said plug means to lock said plug means relative to said body member.

11. The head of claim 10 wherein said camming means comprises a cap in threaded engagement with said body member, said cap having a tapered surface for engaging said locking means, whereby rotation of said cap varies the relative position between said tapered surface and said locking means to adjust said force and vary said predetermined pressure.