A SPRINKLER UNIT

Abstract: The body (1) of the sprinkler unit and the valve body (2) are formed with three cooperating shoulders in the flow pasage (6, 7, 8) to accommodate a seal (3) which, in the working state, serves both as a locking ring for the valve body (2) and to partly elastically absorb changes in the bulb length caused by variations in the ambient temperature, while an 0-ring (4) between the valve body (2) and the bulb (5) absorbs the remaining tensions. The seal (3) automatically slides into position during the obligatory pressure test of the unit, and it is ejected automatically together with the bulb in the event of a release.

Description: A sprinkler unit The invention relates to a sprinkler unit of the type defined in the introductory portion of claim 1 which is supplied from the factory in an assembled state, ready for mounting in situ in an existing piping for the supply of a fire extinguishing fluid in buildings and the like. Such sprinkler units are assembled at the factory by insertion of the bulb into engagement with the bushing and subsequent insertion of the seal and the valve bo¬ dy, and the assembled unit is then subjected to pres¬ sure tests according to current standards. The German Offenlegungsschri ft- 2 300 434 discloses a sprinkler unit of the stated type in which a dual bulp is inserted into the valve body which is to be in¬ serted from the outside to engage the seal, and the bulb and the valve body are then fixed against the inner end of the body by the tightening of the bushing at the • outer end of the body. This insertion operation is com- plicated, and the seal will be under a constant pres¬ sure due to the fixed state. The British Patent Specification 1 582 360 discloses a sprinkler unit of the same type in which the inner end of the bulb is journalled directly in the outer end of the valve body, and the flow passage of the fluid is substantially circular-cylindrical in shape, the surface of the bore in the body having a recess for receiving the seal. This structure requires special care in the mounting operation-, and it is not certain that the valve body will not be sucked backwards and release the bulb in the event that a negative pres¬ sure is generated in the piping when the piping is drained. The British Patent Specification 1 595 116 and the Ger¬ man Offenlegungsschrift 2 921 304 disclose a sprinkler unit of a similar type in which the outer end of the bulb, without any intermediate valve body, engages the body through the seal, which upon insertion is kept in place by insertion of a thin tubular bushing. The fragile end of the bulb is unprotected during the moun¬ ting operation, and in case of release the seal will hang in the body and thus impede out-flow of the fluid. The object of the invention is tb provide a sprinkler unit of the stated type without these drawbacks. This object is achieved according to the invention with a sprinkler unit of the type defined in the character¬ izing portion of claim 1. The invention also relates to a method of assembling such a sprinkler unit and of the type defined in the introductory portion of claim 2, said method being characterized by the steps defined in the character¬ izing portion of claim 2. When the sprinkler unit of the invention is assembled at the factory, the seal is quite. simply placed around the valve body and is urged down by the collar formed by the second shoulder on the valve body surface when the valve body with applied Q-ring is pressed from within out toward the bulb f-irst applied. During the subsequent obligatory pressure test the pres- _ ~- PI - - O ' sure fluid then automatically presses the seal into position between the shoulders at the crank in the flow passage without any additional manual operations being needed-, and the seal will then act both as a locking ring for the valve body against possible inward movement of the valve body in case of a reduction in the pressure in the piping, and as an equalizing means for partial absorption of tensions caused by random variations in the bulb length, without this being at the expense of the sealing function. In the event of a release, the seal will be completely ejected with certainty so that a new bulb can be inserted unimpeded- ly. The 0-ring absorbs the rest of the length variation tensions and provides additional protection against bulb rupture during assembling. The valve body seal may expediently be an 0-riπg of the same material as the 0-ring serving to journal the bulb, preferably VITON R which can resist temperatures up to 250°C. The invention will be explained more fully below with reference to the drawing, in which fig. 1 is a longitudinal section of the sprinkler unit of the invention, ready for sale, and fig. 2 is a longitudinal section of the sprinkler unit during its assembling at the factory. As shown in fig. 1, the sprinkler unit of the invention comprises a body 1 with external threads 9 for applica¬ tion to an existing piping in a fire extinguishing system, a bore 6 serving as a flow channel and having a sealing face 8 which is expanded through an internal OMPI shoulder and which may be parallel with the axial di¬ rection or form an angle with said direction of up to 15°. The body 1 is moreover conventionally extended outwards with two supporting legs 10 which mount a bushing 11 as an outer attachment for the sprinkler bulb 5 of a conventional profile. The valve body 2 of the sprinkler is formed as an end sleeve with a cavity to receive the inner end of the bulb 5 and with an expanded end portion with an external shoulder for a sealing member 3 in the form of an 0-ring forming a tight seal, and an internal shoulder for a second 0-ring 4 to provide an elastic attachment of the neck portion of the bulb 5 and to absorb, together with the seal 3, the expansions and contractions of the bulb caused by changes in the ambient temperature. Like the sealing face 8 of the body 1, the sealing face 7 of the valve body 2 may be parallel with the axial direc¬ tion or form an angle with said direction of up to 15°. The sprinkler unit of the invention is assembled at the factory by passing the bulb 5 through the bore 6 in the body 1 and centering it in the bushing 11. Then the valve body 2 with the seal 3 applied to it is passed into the bore 6, as shown in fig. 2. The assembling of the sprinkler unit is completed by subjecting it to a rated test pressure from the inlet side, and the seal 3 then automatically slides into the locking position, as shown in fig. 1. OMPI Λ *• ttO

Claims: AMENDED CLAIMS [received by the International Bureau on 24 April 1984 (24.04.84); original claim 1 replaced by amended claim 1] : 1. (Amended) A sprinkler unit for use in systems for temperature responsive supply of a pressurized fluid through a piping to extinguish fires in buildings, comprising a body (1) for stationary application to the piping and having an axial central bore (6) extending therethrough, a valve body (2) substantially axially movable with respect to the body in the bore of said body, a seal (3) which is a tight fit between the body and the valve body in the working state, and a heat rupturable bulb (5) whose outer end is inserted between a bushing (11) at the free end of supporting legs (10) protruding outwardly from the body, the inner end of said bulb being journalled against the outer end of the valve body (2) through an 0-ring, the pressurized fluid flow passage (6, 7, 8) between the surface of the bore (6) in the body (1) and the surface of the valve body (2) being formed with a crank (7, 8) in the form of complementary engagement shoulders for the seal (3) at said two faces , c h a r a c t e r i z e d in that the flow passage (6, 7, 8) is profiled with a second shoulder on the valve body (2), said second shoulder being formed upstream and caused to engage with the seal (3) and move it along upon outward movement of the valve body (2). 2. A method of assembling a sprinkler unit of the type stated in claim 1, c h a r a c t e r i z e d by insert¬ ing the bulb (5) from within through the bore (6, 7, 8) in the body (1) to journal the outer end of the bulb in the bushing (11) then inserting the valve body (2) with inserted 0-ring (4) and a loosely applied seal (3) through the bore into engagement with the inner end of BUR£4 OMPI ' .. WlPO the bulb, and subjecting the unit thus assembled to pressure tests according to current standards, which cuases the seal to be pressed into position without additional manipulations. _OMPI < 5 WIPO

Inventors: JACOBSEN ALLAN, JACOBSEN, ALLAN
Applicants: GW SPRINKLER AS, G.W. SPRINKLER A/S
Application year: 1983
Main classification: A62C37
IPC codes: A62C37