EP2433677A2 - Thermal release element for a thermally controlled switch element - Google Patents

Abstract

The member has a glass keg (1) including a gas bubble-filled interior with a release liquid and two ends (2, 5) provided along longitudinal direction opposite to each other. One of the longitudinal ends of glass keg is friction-treated. The friction-decreasing treatment i.e. fire-polishing, takes place in the region of the longitudinal end of the glass keg. The friction-reducing treatment is made by applying an adhering coating (7) on the glass keg, where the coating is made by wax, lacquer or film. One of the ends of the glass keg is provided with a resulting tip (4).

Description

The invention relates to a thermal tripping element for a thermally controlled switching element having the features of the preamble of claim 1.

Appropriate thermal tripping elements in the form of glass vessels, glass flasks or glass vials have long been known and are widely used in different fields of application. They are used to trigger temperature-controlled valves (as a form of a thermally controlled switching element) and are clamped for this purpose usually between a valve closure body and an abutment in its longitudinal course and acted upon in the longitudinal direction with a certain closing force. If the ambient air now heats up above a triggering temperature, this leads to an expansion of the triggering liquid in the interior of the glass bottle and, in the case of a force exceeding the resistance of the glass material due to the pressure of the expanding triggering liquid, the glass bottle breaks, so that the valve closure body is released and the valve opens. A corresponding valve may be, for example, a shut-off valve in a sprinkler system, such as is used for fire protection reasons in buildings. Just as well, the valve can also be a safety valve of a gas container, which should open in case of fire, to blow off the gas contained in the gas container controlled and thus to prevent bursting of the container and thus an explosion. Alternatively, the thermally controlled switching element, for example, but also be an electrical switch, which is held by the thermal release element and against a switching force in an open or closed position and after triggering of the thermal release element by the switching force (eg exerted by a spring) is transferred to the other position.

Corresponding thermal tripping elements in the form of elongated glass bottles are in different design variants, for example in the EP 0 215 331 B1 shown and described. Also shown is how this glass keg is clamped between two abutments.

A thermal tripping element with the features of the preamble of claim 1 is also known from DE 2118790 known. In the trigger element disclosed therein, a thin sealing layer is applied to the first end with the tip, which should consist of a plastic, eg Teflon.

Further examples of similar thermal tripping elements are in the publications GB 409,569 and US 4,217,961 specified. In the EP 0 244 746 For example, a method for treating a glass vessel, in particular a glass ampoule, and such a vessel itself are described, wherein the glass vessel disclosed therein is not that intended for use as a thermal triggering element.

In practice, the switching elements are preassembled, wherein the glass keg is clamped in a position between a movable switching means, such as a closure body of a valve, and the abutment by a deliverable to the switching means of the switching element, typically screwed abutment screwed against one of the longitudinal ends of the glass cask is until reaching a predetermined load or clamping force. The screwable against the end of the glass cask element of the abutment is usually made of metal, often made of brass. When screwing in the abutment portion of this rotates so relative to the end of the glass bottle and brings here a torsional force, which is undesirable because it can change the tripping of the glass fiber in unwanted and usually unpredictable manner. The torsion applied here is the greater, the larger the coefficient of friction between the material of the screwed abutment element and the material of the glass bottle is. This coefficient of friction is comparatively high between the materials typically used, glass and metal, usually brass.

Today, when assembling the glass kegs, a trick is used by applying a drop of oil or a dose of grease to the longitudinal end of the glass keg in connection with the screw-in section of the abutment in order to reduce the friction coefficient accordingly. The dosing of fats or oils in automatic assembly processes, however, is in most cases subject to problems, since it can come here to drip and for sticking or dizzying the dosing unit. In the worst case, dust or dirt particles can be incorporated in such a grease, which then scratch when mounting the abutment on the glass of the glass bottle and cause surface damage, which in turn lead to a change in the tripping characteristic. Incidentally, such metering devices that introduce oil or grease into an automated assembly process are subject to frequent maintenance, which adds to the cost of this assembly process. Also, a dosage often takes place with a significant excess, which leads to an increased consumption of oil or fat, with not least negative for the environment.

Here is to be remedied with the invention by providing a way to use without the addition of grease or oil in the assembly process improved glass kegs as thermal tripping elements in the structure of the thermal switching element, in which when screwing the abutment yet compared to a conventional without oil or Fat running process significantly reduced torsional moment is introduced into the glass keg.

This object is achieved by a thermal tripping element for a thermal switching element having the features of claim 1. Advantageous developments are specified in the dependent claims 2 to 6.

The essential idea according to the invention consists in subjecting a per se known thermal tripping element according to the features of the preamble of claim 1 to at least the second longitudinal end opposite the end of the tip or at both longitudinal ends of a friction-reducing treatment, eg by application may be a adhering to the glass bottle coating, but also in a mere surface treatment such as fire polishing. The thermal triggering element is thus formed in the form of a glass bottle, which has a rounded end at a second of its two longitudinal ends, on which the friction-reducing treatment is performed. This friction-reducing treatment, for example the application of the coating, accordingly no longer takes place in connection with the assembly process, but takes place in particular immediately after the production process of the thermal release elements (glass vessels) before they are packed and ready for further processing, in particular for pre-assembly of the Valve to be shipped. Accordingly, certain requirements must be imposed on the friction-reducing treatment: the result of this treatment must in any case be durable, and in particular an applied coating must adhere so well to the glass keg that it resists further handling of the glass keg in the course of application of the coating. in particular a packing operation, unpacking and transport until insertion into the valve between the closure body and the abutment. In other words, here the thermal tripping element is typically produced in a first production facility, provided there with the friction-reducing treatment and then packaged and then delivered. As a result of the friction-reducing coating adhering to the glass bottle or a reduction in the coefficient of friction achieved by other friction-reducing treatment, such a thermal triggering element can now be integrated directly into the thermal switching element without the previously required introduction of grease or oil, ie between the switching means, eg the closure body a valve, and the abutment are clamped by screwing an abutment element and thus applying a clamping force on the thermal release element. Due to the treatment provided according to the invention, for example by the applied coating, the torsion element is here reduced at least by a value corresponding to the known method of greasing in the assembly process (reductions of about 30% are typically achieved), preferably even more. With inventively designed and treated, in particular coated, thermal tripping elements reductions of the torsion element could be detected by friction reduction in a range between 30% up to 90%, depending on the selected treatment method, when coating also the coating material used. As a coating material with the best friction-reducing properties, which lead to the highest reduction of the torsional moment, coatings have emerged from eg wax, paints, and films.

In general, when choosing a coating, because of the above-described requirement of a certain resistance of the coating during packaging and further handling of the thermal tripping element, it is advisable to apply the coating in the form of a solid phase, as is the case with the already mentioned coating materials.

In order to keep an influence possibly even after the joining of the thermal switching element and clamping the thermal release element to the latter remaining coating material on the release properties of the thermal tripping element as low as possible, it is advisable to apply the friction-reducing coating only at the second longitudinal end of the glass bottle and the Area of the coating as far as possible to reduce the area with which the glass keg with the element of the abutment comes into contact, which moves to clamp on this, in particular screwed and in which thus takes place a possible torsion entry. In this way it is prevented that possibly still elsewhere adhering coating material prevents heat transfer through the glass keg in the inside thereof and thus delays a reaction time for the triggering of the thermal tripping element.

In a presently preferred variant, the glass keg has a circumferential thickening at a first longitudinal end and the tip resulting therefrom, and at its second longitudinal end has the rounded, bulbous finish, the friction reducing treatment preferably being limited to the rounded, bulbous finish only there is, for example a coating is only applied there. Namely, such a thermal tripping element, namely with the pointed end, which is generated when closing the space filled with the tripping liquid, is advanced against the switching means of the thermal switching element, e.g. against the closure body of a valve, set (often with the interposition of a spring element for receiving the closing force), and it is screwed the abutment against the bulbous end of the thermal tripping element. However, the invention is not limited to an implementation in connection with glass kegs of the special geometry described here, but can also be applied to glass kegs formed throughout with the same diameter (without thickenings). There, the second longitudinal end is preferably treated exclusively friction reducing, e.g. coated or surface treated, such as fire polished, which is the longitudinal end which, when installed in a thermal switching element, e.g. a trigger valve, abuts an abutment portion.

A thermal tripping member according to the present invention can be obtained by, after the manufacture of the thermal tripping element in the form of an elongated glass jar with a fully enclosed interior filled with a tripping liquid including a gas bubble, this glass jar with one of its longitudinal ends in a liquefied coating material dipped and so coated at this longitudinal end. Thus, for example, ready-made glass bottles can be clamped in a device and immersed batchwise with the area selected for coating in a corresponding dip, pulled out with adhering coating material from the dip and for solidification of the coating, which is preferably present in a solid phase, are cooled. Subsequently, the thus coated thermal tripping elements in the usual way further processed, in particular packed for shipping and shipped to the assembly of thermal switching elements and unpacked and used. Alternatively, a glass keg can be surface-treated, eg, fire-polished, eg, prior to filling with the triggering liquid and closing for the filling of an open end, ie as a semi-finished product, at the already closed end in order to reduce the coefficient of friction. But such a treatment can also be done on a completely filled and sealed glass kegs, if it is not the same triggering temperature is exceeded.

If desired, residues of a coating adhering to the thermal switching element after assembly may be removed from the thermal tripping element, e.g. by heating below the initiation temperature to melt and drain material of a correspondingly low melting point. However, such a procedure is usually not required, since the coating in the inventive manner preferably strongly limited locally and only in the region of the thermal release element, to which the element of the abutment to be screwed actually abuts and transmitted to the torsional force or a torsional moment becomes.

Fig. 1

in einer schematischen Darstellung von der Seite ein erfindungsgemäßes thermisches Auslöseelement zwischen dem Verschlusskörper eines thermischen Schaltelementes und einem Element des Widerlagers, die jeweils geschnitten dargestellt sind; und

Fig. 2

in einer ähnlichen Darstellung wie in Fig. 1 ein erfindungsgemäßes thermisches Auslöseelement, angeordnet in einem thermischen Ventil, hier einem Brandschutzsprinkler.

Further advantages and features of the invention will become apparent from the following description of an embodiment with reference to the accompanying figures. Showing:

Fig. 1

in a schematic representation of the side of an inventive thermal tripping element between the closure body of a thermal switching element and an element of the abutment, each shown in section; and

Fig. 2

in a similar representation as in Fig. 1 a thermal tripping element according to the invention, arranged in a thermal valve, here a fire protection sprinkler.

In the figures, a thermal tripping element according to the invention in the form of a glass bottle 1 is shown schematically, wherein this glass keg 1 in the Fig. 1 in an arrangement position between a closure body V of a valve and an abutment W is shown. In Fig. 2 is the glass keg 1 completely in an arrangement in a valve, shown here in a sprinkler valve S.

The glass keg 1 has an elongate shape and encloses in its interior (not shown here) an elongated cavity which extends substantially over the entire length of the glass cask 1 and is filled with a triggering liquid and in which a gas bubble is contained in addition to the triggering liquid , The composition of the triggering liquid, its amount, the size of the glass vesicle and the wall thickness of the glass vial 1 determine the factors that are important for the thermal tripping element, such as the triggering temperature and the triggering speed (delay), ie the rate of reaction to an increase in temperature in the environment.

The glass keg 1 has at a first longitudinal end 2 a circumferential, shoulder-like thickening 3, from which a pointed end 4 extends out. This pointed end 4 is formed when closing the glass bottle 1 after filling with the triggering liquid by fusing.

At its second longitudinal end 5, which is opposite the first longitudinal end 2, the glass keg 1 has a likewise thickened bulbous termination 6. At this longitudinal end 5, more precisely in the region of the bulbous close 6, the glass keg 1 is provided in accordance with the invention with a coating 7 indicated here by hatching, which consists of a friction-reducing material in the solid phase. Depending on the selected coating material, a suitable application method is used, eg dipping, gluing, spraying. Preferably, this coating consists of a wax, a paint, a film. Instead of a coating, a surface treatment for reducing friction can also be carried out in the area 7, eg fire polishing.

Already in Fig. 1 schematically shows how in an installed state, the glass keg 1 is clamped in a valve between a closure body V and an abutment W in its longitudinal direction, in which example the glass keg is fixed with its first longitudinal end 2 on the closure body V by the pointed end protrudes into a blind hole B and the glass kegs with the thickening 3 rests on the edge of the blind hole B, and rests with its second longitudinal end 5, more precisely with the bulbous termination 6 at another blind hole BS in the abutment.

It can be seen here that the coating 7 on the glass keg 1 is designed so that it covers the area in which the glass keg 1 rests with its bulge 6 on the portion surrounding the mouth of the blind hole BS in the abutment W. In this way, it is ensured that when fixing the glass cask 1, in which the abutment W, which is substantially cylindrically shaped and has a thread G on its lateral surface, is screwed into a corresponding mating thread and screwed in the longitudinal direction of the glass cask 1 for clamping it , the abutment W over the bulbous end 6 of the glass bottle 1 slides away due to the applied there friction-reducing coating 7. Thus, when screwing the abutment and clamping the glass bottle 1 with the required holding force applied to the glass keg 1 torsional moment is significantly reduced, depending on the used Coating material by 30% up to 90%.

In Fig. 2 is again shown for clarity, as the glass keg 1 is inserted into a sprinkler valve S.

Recognizable again is the above-described seat of the glass bottle 1 between the closure body V and the abutment W. The closure body V serves here for closing a water channel K, in which in the use of the sprinkler valve S water is on which a discharge pressure is applied. The closure body V is sealingly connected to a spring F, which in turn rests sealingly on a shoulder on the outlet side of the water channel K. This spring F is used to record the closing force with which the glass keg 1 in the as in Fig. 2 It also allows the compensation of temperature variations caused by changes in length of the glass bottle 1 and the closure body V and the abutment W make.

The sprinkler valve S is provided with holding struts H, which form between them a dome-like opening in which the glass keg 1 is inserted. The holding struts H open into a threaded opening O, in which the abutment W is screwed with its external thread and thus can be delivered in the longitudinal direction of the glass cask 1 on this. Around the threaded opening O around a distributor star St is arranged, which fanned in the event of triggering the emerging from the water channel K water in a known manner, so as to achieve a broad surface effect for the fire extinguishing.

Once again, it can clearly be seen in this illustration how the coating 7 on the bulbous end 6 of the glass bottle 1 interacts with the abutment W in order to reduce the friction and thus the transmission of a torsional moment when the abutment W is screwed in and bracing the glass bottle 1 ,

It will be apparent to those skilled in the art that the in Fig. 2 shown application of a glass bottle 1 according to the invention for a sprinkler valve S is not the only possible application. Likewise, the glass keg 1 can be used, for example, also in thermally releasing relief valves on compressed gas containers or in comparable applications in which it depends on a thermally controlled release of a valve.

LIST OF REFERENCE NUMBERS

1

glass bulb

2

longitudinal end

3

thickening

4

pointed end

5

longitudinal end

6

bulbous conclusion

7

coating

B

Blind hole

BS

Blind hole

F

feather

G

thread

H

holding strut

K

water channel

O

threaded opening

S

Sprinklerventil

St

distributor star

V

closure body

W

abutment

Claims (6)

Thermal tripping element for a thermal switching element in the form of an elongated glass jar (1) with a fully enclosed, filled with a tripping liquid including a gas bubble interior, said glass keg (1) along its longitudinal direction opposite to each other a first longitudinal (2) a tip (4) emerging from a peripheral edge, in particular a peripheral thickening, and a second longitudinal end (5) having a rounded bulbous termination (6), characterized in that the glass vessel (1) is formed at least at the second longitudinal end (5 ) has been treated to reduce friction. Thermal tripping element according to claim 1, characterized in that the friction-reducing treatment has taken place only in the region of the second longitudinal end (5) of the glass bottle (1). Thermal tripping element according to one of the preceding claims, characterized in that the friction-reducing treatment is a surface treatment, in particular a Feuerpolitur. Thermal tripping element according to one of Claims 1 or 2, characterized in that the friction-reducing treatment is the application of a friction-reducing coating (7) adhering to the glass vessel (1). Thermal tripping element according to claim 4, characterized in that the friction-reducing coating (7) has a solid phase. Thermal release element according to one of claims 4 or 5, characterized by a friction-reducing coating (7) made of wax, lacquer or a film.

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