GB2447297A

GB2447297A - Retaining nested articles using bent tabs

Info

Publication number: GB2447297A
Application number: GB0704573A
Authority: GB
Inventors: Michael Colin Roberts
Original assignee: Rolls Royce PLC
Current assignee: Rolls Royce PLC
Priority date: 2007-03-08
Filing date: 2007-03-08
Publication date: 2008-09-10
Also published as: GB0704573D0

Abstract

A multi-use retention device for retaining nested articles 60, 62 together comprises a multiplicity of bendable tabs 64 and 66-74, which may made of malleable material. In use, one tab 64 may be bent to retain a nested article in position. The nested article may be extracted by displacing bent tabs 64, and then replaced and retained by bending previously unbent tabs. The quantity of tabs may be sufficient for all envisioned replacements of the nested article within the other article. The multi-use retention means may be integral with or independent of a nested article. The device may have advantages in applications with high centrifugal fields.

Description

-1-2447297 Multi-use Retaining Means This invention relates to

multi-use retention means for nested articles that permits subsequent removal of the article and its further retention.

It is often necessary to fit two components together, for example where a circular component is fitted over the shank or inside the bore of another component. Many designs require that the two components are separate, for example to facilitate assembly or to take advantage of different material properties. It is known to fit components together using a retention plate and retaining bolt, however such an assembly adds cost and weight to a design and can result in foreign object damage if the bolt becomes detached.

It is also known to fit components together using a retention tab concept where tabs attached to one component may be bent over to retain the other component once it is in position. This method saves on cost and weight and avoids foreign object damage but can only be used once so must be replaced if the components are separated and subsequently require refitting together, for example during maintenance or repair.

According to the present invention, there is provided multi-use retention means for nested articles comprising a multiplicity of tabs made of malleable material positioned such that at least one tab may be bent to retain one of the articles within the other wherein bent tabs may be displaced to allow extraction of the article.

* Preferably the quantity of tabs is sufficient for all envisioned replacements of the article.

According to another aspect of the present invention there is provided a use of the multi-use retention means to retain nested articles comprising: (a) bending over one tab to fix a nested article in position within another article, (b) displacing the bent tab to allow extraction of the nested article, (C) * replacement of the article back into position, (d) bending over another unbent tab to retain the nested article in position.

In a preferred embodiment of the invention a housing for the article is integral with the multi-use retention means. In a further preferred embodiment of the invention two diametrically opposite tabs may be bent to retain the nested article in position within the housing.

The invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a diagrammatic view of known multi-use retention means using a retention plate and retaining bolt to secure an article within a housing.

Figure 2 is a diagrammatic view of multi-use retention means according to the present invention, used to secure an article within a housing.

Figure 3 is a view in the direction of arrow A of Figure 2.

Figure 4 is a diagrammatic view of an alternative arrangement of multi-use retention means according to the present invention that is independent of a nested article or housing.

Figure 5 is a diagrammatic view of another alternative arrangement of multi-use retention means according to the present invention with tabs made by surface perforations spaced from one end.

Figure 6 is a diagrammatic view of a further alternative arrangement of multi-use retention means according to the present invention with an outwardly bent tab.

In Figure 1 there is shown an article 2 adjacent to a housing 4. A retention plate 6 is secured against arm 8 of housing 4 by retaining bolt 10. An end 12 of retention plate 6 overlaps surface 14 of article 2 to prevent movement of article 2 beyond surface 16 of housing 4.

In Figure 2 there is shown an article 2 adjacent to housing 4. The distal end of housing 4 forms a tab 20, which protrudes beyond surface 22 of article 2. Tab 20 is bent such that end 24 of tab 20 overlaps surface 14 of article 2 to prevent movement of article 2 beyond surface 26 of tab 20.

In Figure 3 housing 4 is shown with two diametrically opposite bent tabs 20 and 24, which overlap surface 22 of article 2. Tabs 26 to 38 of housing 4 protrude beyond surface 22 but are unbent and do not overlap surface 22 to prevent movement of article 2.

After article 2 has been secured in housing 4 by bending tabs 20 and 24 it is then only possible to remove article 2 from housing 4 by displacing tabs 20 and 24, for example by cuthng them off. Article 2 may then be replaced within housing 4 and re-secured by bending another pair of diametrically opposite unbent tabs such as tabs 26 and 32.

In Figure 4 multi-use retention means 40 are shown with bent tab 42 and unbent tabs 44 to 52 formed at one end. In this arrangement retention means 40 are not integral with an article or housing and must be fixed to one of the nested articles, for example by welding.

In Figure 5 multi-use retention means 54 are shown with bent tab 56 and unbent tab 58.

In this arrangement the rectangular tabs are made by surface perforations spaced from one end of retention means 54. Retention means 54 may act as either a nested article or independent retention means.

In Figure 6 there is shown an outer article 60 with an inner nested article 62. A bent tab 64 and unbent tabs 66 to 74 are formed with at one end of inner article 62. In operation bent tab 64 is bent outward over outer article 60 to prevent inner article 62 from retreating further inside outer article 60. Using multi-use retention means in this arrangement has advantages in applications with high centrifugal fields and where a tab is partially bent, for example due to spring-back effect at assembly. Under such circumstances a partially outwardly bent tab will tend to be pulled into the fully bent position whereas a partially inwardly bent tab would be pulled into the unbent position.

Although aspects of the present invention have been described with reference to the embodiments shown in the accompanying drawings, it is to be understood that the present invention would be equally as effective for non-circular multi-use retention means. The present invention also encompasses embodiments where more than two tabs must be bent over at each replacement in order to retain the article securely.

Claims

I Multi-use retention means for nested articles comprising a multiplicity of tabs made of malleable material positioned such that at least one tab may be bent to retain one of the articles within the other wherein bent tabs may be displaced to allow extraction of the article.
2 Multi-use retention means as claimed in claim 1 wherein the quantity of tabs is sufficient for alt envisioned replacements of the article.
3 Multi-use retention means as claimed in claims 1 and 2 wherein a housing for an article is integral with the multi-use retention means.
4 Use of a multi-use retention means to retain nested articles comprising: (a) bending over one tab to fix a nested article in position within another article, (b) displacing the bent tab to allow extraction of the nested article, (c) replacement of the article back into position, (d) bending over another unbent tab to retain the nested article in position.
Use of a multi-use retention means as claimed in claim 4 wherein two diametrically opposite tabs may be bent to retain the nested article in position.
6 Use of a multi-use retention means as claimed in claim 4 wherein more than one tab, but not all tabs, must be bent at each replacement of the nested article for adequate retention.
7 Multi-use retention means as hereinbefore described with reference to Figures 2, 3, 4, 5 and 6 of the accompanying drawings.