GB2206489A

GB2206489A - A triggering element for a fire protection installation

Info

Publication number: GB2206489A
Application number: GB08815232A
Authority: GB
Inventors: Armin Riedle; Horst Zientek
Original assignee: Total Walther Feuerschutz GmbH; Total Feuerschutz GmbH
Current assignee: Total Walther Feuerschutz GmbH; Total Feuerschutz GmbH
Priority date: 1987-07-06
Filing date: 1988-06-27
Publication date: 1989-01-11
Anticipated expiration: 2008-06-27
Also published as: GB2206489B; CH677323A5; GB8815232D0; DE3808384C2; DE3808384A1

Description

2 220 6 4 8 9 is A TRIGGERING ELEMENT This invention relates to a

triggering element for thermally and/or electrically triggering a fire protection installation, for example a sprinkler installation, the triggering element being made of glass and being filled to bursting point with a liquid -(hereafter referred to as the "bursting liquid").

A triggering element of this type normally maintains the valve in a sprinkler head closed; however, in the event of fire the bursting liquid in the triggering element expands in response either to the increase in temperature or to an electrical impulse and bursts the element thereby opening the valve in the sprinkler head. The delay in bursting of the element is hereafter referred to as the "bursting time". In principle, the triggering element has two tasks to fulfil. Firstly, it must absorb the clamping forces imposed by the sprinkler housing so as to keep the valve closed at.all times when there is no fire.

Secondly, it must explode rapidly in the event of fire so that the extinguishing process can begin as quickly as possible. In this connection, it is necessary for the sprinkler heads to remain in working order for decades.

Numerous triggering elements are known which attempt to combine both of these functions in an optimum manner. Thus, attempts have been made to increase the clamping forces by various designs of the glass triggering element (US-1 733 701), without thereby increasing the bursting time. It is also known to reduce the bursting time by inserting a displacement body within the bursting liquid in the triggering element (DE-A-32 20 124).

The present invention provides a triggering element which can be manufactured economically by the simplest of methods, without thereby impairing the requirements of adequate stability during clamping and a short bursting time in event of fire.

According to the present invention, there is provided a triggering element for use in a fire protection installation, said element being formed from a member which has a thin-walled cylindrical intermediate region partially defining a chamber which is filled with a bursting liquid, and said member being closed at each of its opposite end regions by a closure member, the closure member at one of said opposite end regions including a sealed passageway through which, prior to sealing, the chamber has been filled.

According to another aspect of the invention there is provided a hollow element which is to be filled with a bursting liquid and sealed for use as a triggering element in a fire protection installation, said element being formed from a member which has a thin-walled cylindrical intermediate region partially defining a chamber to be filled with the bursting liquid, and said member being closed at each of its opposite end regions apart from a sealable passageway in one end region via which said chamber is to be filled with said bursting liquid.

Typically, the filling hole is sealable by melting.

According to a further aspect of the invention, there is provided a sprinkler assembly having a sprinkler outlet which is sealed by a triggering element in accordance with the first aspect of the invention.

In the sprinkler assembly, the triggering element is preferably clamped between a seal at said outlet and a bracket opposing the outlet.

The triggering element of the invention is preferably formed from a cylindrical glass tube, which c can be simply manufactured, the length of which is somewhat greater than the required height of the shaft which is to form the chamber for receiving the bursting liquid. The closure members or stoppers are also preferably made of glass. The projecting ends of the glass tube can be easily sealed to form the closure members. The length and strength of the closure members are thereby designed such that they transmit axial clamping forces optimally onto the thin wall of the cylindrical tube part. Cylindrical glass tubes with melted-on closures for stabilization are known in the case of neon tubes (see, e.g. DE-A-29 30 249). However, these tubes are not filled with a bursting liquid, but with an inert gas, which is not provided for bursting the glass body.

In order to improve the fatigue strength of the triggering element in the case of axial loading, it is further proposed that each closure member should preferably comprise a plane surface extending perpendicular to the central axis, the lower plane surface resting, in use, flat against a plane surface of a sealing part of the sprinkler housing and the upper plane surface resting, in use, flat against a plane surface of an opposing counterpart of the sprinkler opposing the sealing part.

As a result of this measure, the cylindrical shaft part of the triggering element with the thin wall thickness is only acted upon by compressive forces, so that this sensitive part remains free of all bending and shearing forces.

In order to improve the transmission of the axial forces onto the central cylindrical part of the triggering element it is also proposed that in the sprinkler assembly, the sealing part and the opposing counterpart each comprise a collar, the inner surfaces of which extend parallel to the central axis, so that the outer surfaces to the closure members can rest flat against these inner surfaces.

In order to prevent the occurrence of high stresses at the transition points between the cylindrical outer surfaces of the closure members and the plane surfaces extending perpendicular thereto, it is proposed that a rounded portion be provided here in each case. A further improvement of the fatigue strength of the triggering element during axial loading is obtained if each closure member is provided on the outside with a tension member which securely spans the closure member.

By using tension members it is ensured that the stopper can absorb transverse forces without damaging the triggering element and the cylindrical shaft part of the triggering element having the thin wall thickness is therefore only acted upon by compressive forces, so that this sensitive part remains free of all bending and shearing forces.

In order to improve the transmission of the axial forces onto the central cylindrical part of the triggering element it is further proposed that the tension members be formed as closed caps and/or cap rings, which are guided into the region of the cylindrical tube, it being possible to connect the caps or cap rings securely with the stoppers by means of an elastic material.

Most preferably, the closure members are integral with the cylindrical intermediate region.

For a better understanding of the present invention and to show how the same may be carried into effect, reference will now be made to the accompanying drawings in which:

Figure 1 shows in section a triggering element in accordance with the present invention; Figure 2 is a cross section through a sprinkler 1 including a triggering element in accordance with present invention; Figure 3 is an enlarged view of a triggering element in accordance with the present invention; Figure 4 is a further embodiment of the upper part of a triggering element in accordance with the present invention; Figure 5 is a cross section through a sprinkler with a further triggering element in accordance with the present invention; Figure 6 is an enlarged view of one end of a triggering element in accordance with the present invention; Figure 7 is an enlarged view of one end of another is triggering element in accordance with the present invention; and Figure 8 shows the upper part of a triggering element in accordance with the present invention with a tie rod as a tension member.

The triggering element 1 shown in Figure 1 is formed from a cylindrical glass tube 2 having a thin wall thickness 3, in which the ends 9 and 10 are melted to form stoppers or closure members 4 and 5. In this connection, the stopper 5 is provided with a filling hole 6, which is sealed by melting at the end 8 after the inner chamber 7 has been filled with a bursting liquid.

Figure 2 shows a sprinkler assembly 11 having a sprinkler housing 12 and a sprinkler bracket 13 with a spray plate not shown in further detail. The sprinkler 11 is closed by means of the triggering element 1 and a sealing part 14, the triggering element 1 resting at the other end against an opposing counterpart 15. By means of devices which are not shown, the triggering element 1 is maintained under pressure, so that the sealing part 14 rests in a sealing-tight manner against -6 the sprinkler housing.

The triggering element 1 comprises a central cylindrical tube part 16 defining an inner chamber 7 having a thin wall thickness and two stoppers 4 and 5, the lower stopper 5 being provided with the filling hole 6, which was sealed at the end 8 once the inner chamber 7 had been filled with bursting liquid. The inner chamber 7 is formed at its upper end as"a hemisphere 31 and at its lower end as a funnel 32.

With reference now to Figure 3, in order that the sealing forces acting upon the triggering element 1 only exert axial compressive forces on the central cylindrical tube part 16, plane surfaces 17 and 18 are provided in the region of the stoppers 4 and 5, which plane surfaces extend perpendicular to the central axis 39 of the triggering element 1. Rounded portions 21 and 22 are provided between said plane surfaces 17 and 18 and the cylindrical outer surfaces 19 and 20 of the stoppers 4 and 5. The triggering element 1 rests with its plane surface 18 against a plane surface 23 of the sealing part 14. The plane surface 17 rests against a plane surface 24 of the counterpart 15 (see Figure 2).

In order to avoid bending and shearing forces, the sealing part 14 and the counterpart 15 are each provided with a collar 25 and 26, which collars have inner plane surfaces 27 and 28 extending parallel to the central axis 39 of the triggering element 1, so that the cylindrical outer surfaces 19 and 20 of the stoppers 4 and 5 also rest flat against the inner surfaces of the collars 25 and 26.

In the embodiment shown in Figures 2 and 3, the triggering element 1 is provided in the region of the stopper 4 with an upper reinforcing part 4a. As shown in Figure 4, this part 4a can be dispensed with, so that a continuous plane surface 29 is produced. In order that compressive forces are only transmitted in the outer region of the stopper 4, the counterpart 15 comprises a central recess 30.

In order that the sealing forces acting upon the triggering element 1 only exert axial compressive forces on the central cylindrical tube part 16, according to Figure 5, the stoppers 4a and 5 are provided in each case with a tension member which tightly spans the stopper. Said tension members can be formed as closed caps 33 or cap rings 34, which are securely connected by means of a plastic material 35, 36 with the stoppers 4, 5. For reasons relating to corrosion, the cap and cap ring are manufactured from aluminium, brass or the like. According to the invention, and as shown in Figures 6 and 7, the sealing part 14 and/or the counterpart 15 may alternatively be formed as a tension member, thereby tightly enclosing the triggering element 1 with a collar 24, 25 which is extended in to the region of the cylindrical tube part 16. In this case too, an elastic material 35, 36 is provided between each end region of the triggering element 7 and the parts 14, 15.

Figure 8 shows a tension member formed as a tie rod 37, which is securely tensioned as an 0-ring in a groove 38 in the stopper 4, 5. Said tie rod 37 can also adsorb transverse forces, so that the thin cylindrical shaft part 10 remains free of bending and shearing forces.

is

Claims

1. A triggering element for use in a fire protection installation, said element being formed from a member which has a thin-walled cylindrical intermediate region partially defining a chamber which is filled with a bursting liquid, and said member being closed at each of its opposite end regions by a closure member, the closure member at one of said opposite end regions including a sealed passageway through which, prior to sealing, the chamber has been filled.

2. A triggering element according to claim 1, wherein each of the closure members tapers in an axial direction away from the intermediate region.

3. A triggering element according to claim 1 or 2, wherein each closure member comprises a plane surface which extends perpendicular to a central axis of the element.

4. A triggering element according to claim 1, 2 or 3, wherein a rounded portion is provided in each case between the outer cylindrical surface of the tube and said plane surface of the triggering element.

5. A triggering element according to any preceding claim, wherein at least one of the closure members is provided on its outer surface with a tension member which securely spans the closure member.

6. A triggering element according to claim 5, wherein each closure member is provided with a tension member.

7. A triggering element according to claim 5 or 6, wherein the tension members are formed as closed caps andlor as cap rings which extend to the intermediate region of the element.

8. A triggering element according to claim 7, wherein the caps or cap rings are securely connected with the closure members by means of an elastic 2 is material.

9. A triggering element according to claim 7 or 8, wherein the caps and the cap rings are formed from a non-ferrous metal.

10. A triggering element according to claim 9, wherein the non-ferrous metal is aluminium or brass.

11. A triggering element according to any preceding claim, wherein the closure members are covered on their outer surfaces with an elastic material.

12. A triggering element according to claim 5, wherein the tension member is formed as a circumferential tie rod which is securely tensioned in a groove in the closure member.

13. A triggering element according to claim 12, wherein the tie rod is formed from an 0-ring.

14. A triggering element according to claim 13, wherein the 0-ring is formed from a copper wire.

15. A triggering element according to any preceding claim, wherein the inner surface of the chamber includes a hemispherical portion at one end and a funnel-shaped portion at the other end.

16. A triggering element according to any preceding claim, wherein each closure member is integral with the cylindrical intermediate region.

17. A sprinkler assembly having a sprinkler outlet which is sealed by a triggering element as claimed in any preceding claim.

18. A sprinkler assembly according to Claim 17, wherein the triggering element is clamped between a seal at said outlet.and a bracket opposing the outlet

19. A sprinkler assembly according to claim 18, wherein the closure members of the triggering element each comprise a plane surface which extends perpendicular to the central axis of the element, one plane surface resting flat against a plane surface of the seal and the other plane surface resting flat against a plane surface of the bracket opposing the outlet.

20. A sprinkler assembly according to claim 18 or 19, wherein the seal and the bracket each comprise a collar, the inner surfaces of which extend parallel to the central axis of the triggering element, the outer surfaces of each closure member resting flat against the inner surface of its respective collar.

21. A sprinkler assembly according to claim 20, wherein the bracket and/or seal are formed as tension members and enclose the triggering element with its respective collars in a sealing-tight manner.

22. A sprinkler assembly according to claim 21, wherein the collars are extended into the region of the cylindrical tube of the triggering element.

23. A hollow element which is to be filled with a bursting liquid and sealed for use as a triggering element in a fire protection installation, said element being formed from a member which has a thin-walled cylindrical intermediate region partially defining a chamber to be filled with the bursting liquid, and said member being closed at each of its opposite end regions apart from a sealable passageway in one end region via which said chamber is to be filled with said bursting liquid.

24. A triggering element substantially as hereinbefore described with reference to the accompanying drawings.

25. A sprinkler assembly substantially as hereinbefore described with reference to the accompanying drawings.

Published Ign at Ilie Patenz nffife. Slatr- House. 6671 High Ho'born, London WC1R 4TP- Further cop12s may be obtained from The Patent Office.