WO2003033305A1

WO2003033305A1 - Roof rail

Info

Publication number: WO2003033305A1
Application number: PCT/GB2002/004632
Authority: WO
Inventors: Andrew William Bull; Robert Michael Baxter; Paul Novak; Wayne Neil Staples
Original assignee: Thule Automotive Limited
Priority date: 2001-10-13
Filing date: 2002-10-11
Publication date: 2003-04-24
Also published as: GB0124675D0

Abstract

A vehicle roof rail comprises at least one roof rail extrusion attached to a vehicle roof by at least one roof rail foot, which foot comprises a foot member and cover means attached thereto, wherein the cover means is a pressure formed metal section.

Description

ROOF RAIL

The present invention relates to vehicle roof rails.

Roof rails for carrying items on the roof of a vehicle generally consist of at least two roof rail extrusions which may be made of aluminium, and which extend in parallel with each other along each side of the roof. Roof rail feet are attached to either end of each roof rail extrusion and are firmly secured to the vehicle roof.

Virtually all. roof rails fitted to current vehicles use either solid, die-cast roof rail feet, or skeleton feet which have a plastic, moulded cover which is snap-fitted thereon. Solid die-cast feet are very heavy and are, therefore, generally very unpopular with vehicle manufacturers. In addition, they are expensive to manufacture. However, solid die-cast feet do offer the possibility of a good surface appearance since they may be powder-coated and painted to match the colour of the aluminium rail extrusion. The current trend with roof rails is to have them in a silver colour. Unfortunately, due to the alloys used in the pressure die-casting process, it is not possible to produce a silver, anodised rail using this method.

The plastic moulded covers used with skeleton feet are much lighter than the materials used for die-casting and so they are more popular with vehicle manufacturers . However, a problem encountered with this type of roof rail foot is that it is very difficult to achieve an acceptable colour match between the plastic cover and the aluminium roof rail extrusion. Unfortunately, the plastic materials moulded to form the covers are not sufficiently resistant to high temperatures to allow the use of powder coatings and paint. Therefore, it is not possible to produce an acceptable silver, anodised appearance using a plastic cover.

Some more expensive vehicles use an alternative technology called "hydroforming" to produce a one-piece roof rail which consists of an aluminium tube which is inflated by water pressure into a die cavity to create the finished shape of the rail. Unfortunately, this method is very expensive and unsuitable for less expensive vehicles where the overall cost of the roof rail is taken into account. Furthermore, there is a relatively low limit as to how much one can inflate the aluminium tube and therefore the process has certain design limitations.

It is one aim of embodiments of the present invention to. address the above problems and to provide a vehicle roof rail foot which, overcomes the above problems.

According to a first aspect of the present invention, there is provided a vehicle roof rail comprising at least one roof rail extrusion attached to a vehicle roof by at least one roof rail foot, which foot comprises a foot member and cover means attached thereto, wherein the cover means is a pressure formed metal section.

The pressure formed cover means may be produced by stamping, preferably between two dies.

The pressure formed cover means may be produced by stamping, The cover means may be powder coated. The foot member may comprise a skeleton foot. Preferably, the cover means is arranged to be snap-fitted onto the foot member. Preferably, the roof rail comprises at least two roof rail feet substantially at either end thereof. Preferably, the or each roof rail foot is secured to the roof panel by fixing means.

Advantageously, the roof rail foot weighs considerably less than a die-cast roof rail foot having an equivalent design. Advantageously, the cover means has improved design freedom than an equivalent foot manufactured using a hydro-forming process. Advantageously, the cover means has significantly lower tooling costs and very, much extended tool life compared to either hydro-forming . or solid die-casting processes.

Advantageously, the cover means may be powder coated using the same powder coat as the rail extrusion. Therefore, the pressed metal foot cover improves colour matching between the exterior surface of the foot and the roof rail extrusion. Finally, the cover means exhibits improved exterior surface characteristics and may be anodised to form an acceptable silver colour. Such exterior surface characteristics include avoidance of the defects caused by prior art processes such as surface porosity as produced by die castings, and sink marks and flow lines as produced by plastics.

According to a second aspect of the present invention, there is provided a method of producing a roof rail foot according to the first aspect, said method comprising the steps of : - (i) creating features of the cover means by pressure forming; (ii) removing surplus material produced by step (i) ; and 5 (iii) creating final cut edges of the cover means.

The method may also comprise the step in which any extra features required on the cover means are created. For example, said extra features may include the inclusion of 10 means for clipping the cover means to the foot, and optionally, means to align the cover means and the . extrusion.

According to a third aspect of the present invention, .

15. there is provided a vehicle comprising a roof rail;" according to the first aspect. ■■'■

According to a fourth aspect of the present invention,,"¹ there is provided cover means operable to be attached to a"ϊ 20 foot member of a roof rail foot, wherein said cover means is a pressure formed metal section.

All the features described herei may be combined with any of the above aspects, in any combination.

25

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will be made, by way of example, to the accompanying drawings, in which: -

30

Figure 1 shows a schematic perspective view of a roof rail system; and Figure 2 shows a schematic perspective view of a roof rail foot .

Referring to Figure 1, there is shown a roof 4 of a vehicle 2. For clarity, the majority of the vehicle 2 is not shown in Figure 1. A roof rail system is shown in position on the roof 4 of the vehicle 2 and consists of two aluminium roof rail extrusions .8 which extend in parallel with each other along each side of the roof 4. A roof rail foot 6 is attached by suitable means to either end of the roof rail extrusions 8 at attachment sites 12. The roof rail feet 6 are firmly secured to the roof 4 by suitable securing means 16 at site 10. .

Referring^' to- Figure 2, the roof rail" .foot 6 is show ¹' in greater detail consisting of a skeleton structure 18 which

^■ is designed to covered by a cover section 20. The cover section 20 is shown for clarity separate from the skeleton structure 18.

The cover section 20 of the roof rail foot 6 is formed by the well-known pressed metal method in which a sheet of metal is formed in to the shape required by forcing two dies together with the sheet metal between. The pressed metal method is also known as "stamping" . ^■ The main features of the cover section 20 are first produced using an initial "drawing" step. The majority of any surplus material resulting from the drawing step is then removed by a "trimming" step. Final cut edges are produced by a clipping step and, finally, any extra features which are necessary on the cover section 20 are formed using a standard "form end flange" step. The skeleton foot 18 has snap-fit fittings 20 which are required to allow the cover section 20 to be secured to its respective foot 6. Alternatively, the cover section 20 is formed with snap-fit fittings (not shown) which are required to allow the cover section 20 to be secured to its respective foot 6.

Accordingly, advantages of the roof, rack feet 6 and specifically the cover section 20 reside in the fact that they are light and, being metal, may be powder-coated using standard: techniques and using the same powder coat as that used, for the aluminiu roof rail extrusion 8. Alternatively, the feet 6 covers may be anodised using.' the * same anodising process as for the other rail components, i.e. the extrusion 8, thereby producing a silver colour. Pressed metal cover sections 20 are preferred to using solid, die-cast feet which are very heavy .and expensive, or. plastic covered skeleton feet with which it -< is impossible to anodise to produce a silver colour. ■'

Accordingly, use of this type of roof rack foot 6 effectively eliminates the colour mis-matching problems encountered between the colour of the feet 6 and rail 8 by using prior art roof rail feet 6.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) , may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly .stated otherwise, each, feature disclosed is one example only of a generic series of equivalent or similar features; - . ■•[

The. invention is not restricted ..to the . details of'^'!*- the foregoing embodiment (s) . The invention extend to any novel one, or any novel combination, of the features disclosed in ..this . specification (including any accompanying claims, abstract and drawings) , or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A vehicle roof rail comprises at least one roof rail extrusion attached to a vehicle roof by at least one roof rail foot, which foot comprises a foot member and cover means attached thereto, wherein the cover means is a pressure formed metal section.

2. A vehicle roof rail according to claim 1, wherein the pressure formed cover means is produced by stamping..

3. A vehicle roof rail according to either claim 1 or claim 2, wherein the cover means is anodised. < '^■:■ ^■

4. A vehicle roof rail according, to any:of- claims 1 to' -3, wherein the. cover means is powder coated.. . . ^{• ■} ' ⁱ< -

5. A vehicle roof rail according to any preceding ^■ claim, wherein the foot member comprises a skeleton foot . . • "

6. A vehicle roof rail according to any preceding claim, wherein the cover means is arranged to be snap-fitted onto the foot member.

7. A vehicle roof rail according to any preceding claim, wherein the roof rail comprises at least two roof rail feet substantially at either end thereof.

8. A vehicle roof rail according to any preceding claim, wherein the or each roof rail foot is secured to the roof panel by fixing means .

9. A method of producing a roof rail foot according to any of claims 1 to 8, said method comprising the steps of :-

(i) creating features of the cover means by pressure forming; (ii) removing surplus material produced by step

(i) ; and (iii) creating final cut edges of the cover means.

10. A method according to claim 9, wherein the method also comprises the step in which any extra features required on, the cover means are created.

11. A method according to claim 10, wherein.. said extra features include the inclusion of means for clipping? the. cover means to the foot, and optionally, means to align the cover means and the extrusion.. ^{• ι;}

12. A vehicle comprising a roof rail according to any of claims 1 to 8.

13. Cover means operable to be attached to a foot member of a roof rail foot, wherein said cover means is a pressure formed metal section.