GB2201756A

GB2201756A - Fitting tubular components inside conduits

Info

Publication number: GB2201756A
Application number: GB08804540A
Authority: GB
Inventors: Daniel Nervi
Original assignee: ALDES
Current assignee: ALDES
Priority date: 1987-03-03
Filing date: 1988-02-26
Publication date: 1988-09-07
Anticipated expiration: 2008-02-26
Also published as: DE3806971C2; ES2007795A6; IT1219057B; GB2201756B; GB8804540D0; IT8867154A0; DE3806971A1; FR2611852A1; FR2611852B1

Description

2201756 FITTING OF TUBULAR COMPONENTS INSIDE CONDUITS The present

invention relates to the f itting of tubular components such as firebreak valves inside conduits such as ventilation ducts.

FR-PS 2 082 387 describes a firebreak valve consisting of a cylindrical sleeve and an internally mounted foldable transverse shuttery the shutter being attached to the wall of the sleeve at two diametrically opposite point s held in the folded position by a fusible element, and adapted to unfold if a rise in temperature causes the fusible element to melt, thereby completely closing the sleeve by coming to rest on its internal wall.

Valves of this type are designed to slide into a ventilation duct. usually of the same cylindrical form as and having a corresponding diameter to that of the valve sleeve,, so that the duct will be closed if its internal temperature reaches an abnormal level.

The fitting of such firebreak valves is left to the discretion of the installer. Generally speaking,. the valves are slid, more or less easily, into the ventilation ducts, and fit more or less tightly therein, depending on the condition. diameter and ovality of the ductsr with the result that a tight seal between the duct and the valve is seldom if ever attained.

The object of the present invention is to remedy these disadvantages and more particularly to provide for fitting such valves, and nore generally other elements of cylindrical formr inside conduits in such a manner that the said elements automatically product complete closure of the conduits and the sealing problems hitherto encountered are eliminated.

According to the invention, this object is achieved by providing a tubular component comprising a cylindrical sleeve, with a skirt of substantially conically expanding bell shapes, the extreme diameter of the skirt exceeding that of a conduit into which it is to be f itteds, and the entire periphery of the skirt being divided by substantially axial slits into a ring of resilient teeth which extend substantially axially and overlap each other.

Thuss. the tubular component can be inserted into the respective conduit by leading with the further end of -the.cylindrical sleeve from the teeth, which "shrink" together and overlap more and more as the sleeve slides progressively into the conduit, until the extreme diameter is reduced to the exact internal diameter of the conduit.

The elasticity of the teeth enables them to maintain constant contact with the inner wall of the conduits, thereby securing the component in place thereino, while their flexibility and overlapping provide compensation f or anydiametrical errors or mis-shaping (ovality) of the conduit.

Thuss, the component of the invention compensates for the vari;-:k..bIP tolerances in the conduits and ensures sealing between the conduit and the outer wall of the sleeve. Itfurther allows the adaptation of the cylindrical sleeve or valve to a range of conduit sizes determined by the extreme -dimensions of the conical 'skirt.

Each tooth,:.-,7an be bounded by two precisely a,!.zially extending slits but it is equally possible to form teeth by slits extending somewhat helically, thereby making the teeth longer and correspondingly more flexible.

Side edges of the teeth can be bent inwards by their thickness in the overlap zone,, so that they exhibit a substantially unbroken exterior surface in the said zone and thereby improve the sealing action.

Embodiments of the invention will now be described, by way of nonlimiting examplesi, with reference to drawings of embodiments thereof. In the drawings:

Figure I is an axial section through a valve in accordance with the invention f itted inside a ventilation duct; Figure 2 is a perspective view of the valve in Figure 1; Figures 3 and 4 are detailed views showing the overlapping of the teeth before and after fitting the valve; Figure 5 is a similar view to Figure 3y but showing a different embodiment of the teeth; Figure 6 is an axial half-section of another embodiment of the invention; and Figures 7 to 9 are side elevations of three f urther embodiments.

Figures 1 and 2 show a valve 1 of the type disclosed by FR-PS 2 082 387, fitted inside a ventilation duct 2# the valve I consisting basically of a cylindrical sleeve 3 and an internally mounted foldable transverse shutter 4 attached to the wall of the sleeve 3 at two diametrically opposite points 5.

As shown more particularly by Figures 2 and 3f the sleeve 3 of the valve 1 is provided with a skirt 6 of substantially conically expanding bell shape#, the extreme diameter of which exceeds the internal diameter of the duct 2 in which the valve 1 is to be fitted. The entire periphery of the skirt 6 is divided by axial slits 7 into a ring of teeth 8 regularly spaced round the skirt 6r and the longitudinal edges 8a of adjacent teeth overlap each other prior to insertion. The skirt is made by the intrinsically known operations of deep drawingr tooth cutting and press forming.

AS can be seen f rom Figure l# the valve 1 is inserted into the conduit 2 with the turther end from the teeth 8 leading. During insertiony the teeth 8 "shrink" together and their adjacent edges 8a overlap more and more, as shown in Figure 4s, until the extreme diameter of the skirt 6 attains the internal diameter of the conduit 2.

The elasticity of the teeth 8 enables them to maintai n constant contact with the inner wall of the conduit 29, thereby securing the valve 1 inside the conduit. Moreover#, their flexibility and. overlapping along the longitudinal edges 8a provide compensation for any diamensional errors in the conduit 2s, including mis-shaping (ovality).

Thll--- the slit skirt of the invention compensates for the variable manufacturing tolerances and ensures sealing between the inner wall of the conduit 2 and the outer wall of the valve 1. It further allows the adaptation of the valve tv a r6nge---ofconduit sizes. determine-d-by, the extreme dimensions of the conical skirt 6.

The skirt can be formed integral with the sleeve 3 of the valve 1, or made separately from sheet materialr and il j attached to the sleeve, as by weldingi, riveting or the like (as indicated in Figure 6).

In order to improve the sealing action between the inner wall of the conduit 2 and the outer wall of the skirt 6s, side edges 8a of the teeth 8 can'be bent inwards by their thickness#, as shown in Figure 5#, to form a substantially unbroken external cylindrical surf ace in the tooth overlap zone.

Moreover, the teeth 8 can be given dif f erent shapes, as illustrated in Figure 7 to 9.

In the case of Figure 7j, the teeth 18 are formed by cuts 17 extending somewhat helically round the periphery of the skirt 7j, i.e.,, the cuts 17 are slightly angled from the axial direction, compared with the cuts 7 previously described. This embodiment provides a means of making the teeth 18 longer and correspondingly more flexible.

In the case of Figure 8, the teeth 28 are formed by axial slits 27,, as in the case of the teeth 8. However,, their tips 29 are bent inwards to all ow the valve 1 to be inserted into a conduit in either direction.

Finallyp Figure 9 shows a further embodiment in which the teeth 38 are formed by a combination of axial slits 37,, and radial slits 39. This embodiment enhances the flexibility or elasticity of the teeth 38 and thus allows them to be of larger extent in the peripheral direction (i.e. wider) than in the previous embodiments.

Claims

A tubular component for fitting inside a conduit and comprising a cylindrical sleeve with a skirt of substantially conically- expanding bell shaper the extreme diameter of the skirt exceeding that of a conduit into which it is to be f ittedr and the entire periphery of the skirt being divided by substantially axial slits into a ring of resilient teeth which extend substantially axially and overlap each other.
2. A component as in Claim lr wherein each tooth is bounded by two precise ly axially extending slits.
3. A component as in Claim 1, wherein the teeth are formed by a combination of axial and radial slits.
4. A component as in claim It wherein the teeth are formed by slits extending somewhat helically.
5. A component as in any of Claims 1 to 4, wherein side edges of the teeth are bent inwards by their thickness in the overlap zoney so that the teeth exhibit a substantially. unbroken exterior surface in the said zone.
6. A component as in any one of Claims 1 to 59, wherein the tip of each tooth is bent inwards.
7- A component as in any of Claims 1 to 6. characterised in that the skirt is made separately from sheet material and attached to the sleeve.
8. A tubular component for fitting inside a conduit substantially as hereinbefore described with reference to Figures 1 to 4 or as modified by any one of Figures 5 to 9 of the accompanying drawings.

Published 1988 at The Patent Office, State House, 86/71 High Holborn, London WClR 4TP. Further copies may be obtained from The Patent Offtce, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1/87.

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