Yielding Post of Thin Sheet Metal and Method of Arranging Street Lighting
Street lighting is positioned with lamp posts of sheet metal that have a round or polygonal cross-section and one or more longitudinal welded joints (17-20; 24). Posts are used that have one longitudinal welded butt joint with a weld that covers only a part of the sheet metal thickness and the posts are positioned so that this joint is directed towards the traffic.
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The invention relates to yielding posts of sheet metal that have a round or polygonal cross-section and one or more longitudinal welded joints. The invention also relates to a method of arranging street lighting with yielding posts.
BACKGROUND OF THE INVENTIONLamp posts along roads shall now be yielding and decelerate a colliding vehicle over a fairly long distance. This is achieved if the posts bend backwards over the vehicle, so that the entire post is deformed when the vehicle continues forwards. Conical posts are known from WO 2008/127168 that are roll-formed and have a welded longitudinal joint. Such roll-formed posts can be produced from such a small sheet metal thickness that they bend on collision in spite of being very sturdy against wind forces. Tall posts have such a large diameter at the bottom, however, that they can offer undesirably great resistance before they bend.
OBJECT OF THE INVENTIONAn object of the invention is to ensure that the post bends backwards when run into. Another object is to make the production of the post simpler and faster and more reliable.
BRIEF DESCRIPTION OF THE INVENTIONAccording to the invention, posts are used that have a longitudinal welded butt joint with a weld that is thinner than the sheet metal thickness and the posts are positioned so that this joint is directed towards the traffic. The invention is defined by
The corners stiffened against wind forces are deformed more easily in the event of crash loading than the other corners in the polygonal cross-section and the joint 24 can expediently be executed in one of the corners stiffened against wind forces. Lamp posts according to
Posts according to
Claims
1. Yielding post of thin sheet metal with a polygonal or round cross-section with at least one longitudinal welded butt joint (17-20,24), wherein the weld (23) has a smaller thickness across the sheet metal than the sheet metal thickness.
2. Post according to claim 1, wherein the weld (23) has a thickness of less than ¾ of the sheet metal thickness.
3. Post according to claim 1, wherein the edges (21,22) facing the weld are bevelled.
4. Post according to claim 1, wherein the weld (23) is a laser weld.
5. Post according to claim 1, wherein it is a lighting post by the road and has a longitudinal welded joint (17-20, 24) directed towards the traffic.
6. Post according to claim 5, wherein the lighting post is roll formed and has only one longitudinal joint (24).
7. Method of arranging street lighting with lamp posts of sheet metal that have a round or polygonal cross-section and one or more longitudinal welded joints (17-20; 24), wherein posts are used that have one longitudinal welded butt joint (17-20; 24) with a weld (23) that has a smaller thickness across the sheet metal than the sheet metal thickness and the posts are positioned so that this joint is directed towards the traffic.
8. Method according to claim 7, wherein posts are used with a laser welded joint with a weld thickness of less than ¾ of the sheet metal thickness.
9. Method according to claim 8, wherein posts are used that are roll formed in one piece so that they have only one longitudinal joint (24).
10. Post according to claim 2, wherein the edges (21,22) facing the weld are bevelled.
11. Post according to claim 10, wherein the weld (23) is a laser weld.
12. Post according to claim 3, wherein the weld (23) is a laser weld.
13. Post according to claim 2, wherein the weld (23) is a laser weld.
14. Post according to claim 13, wherein it is a lighting post by the road and has a longitudinal welded joint (17-20, 24) directed towards the traffic.
15. Post according to claim 12, wherein it is a lighting post by the road and has a longitudinal welded joint (17-20, 24) directed towards the traffic.
16. Post according to claim 11, wherein it is a lighting post by the road and has a longitudinal welded joint (17-20, 24) directed towards the traffic.
17. Post according to claim 10, wherein it is a lighting post by the road and has a longitudinal welded joint (17-20, 24) directed towards the traffic.
18. Post according to claim 4, wherein it is a lighting post by the road and has a longitudinal welded joint (17-20, 24) directed towards the traffic.
19. Post according to claim 3, wherein it is a lighting post by the road and has a longitudinal welded joint (17-20, 24) directed towards the traffic.
20. Post according to claim 2, wherein it is a lighting post by the road and has a longitudinal welded joint (17-20, 24) directed towards the traffic.
Type: Application
Filed: Mar 22, 2012
Publication Date: Jan 2, 2014
Applicant: Northcone AB (Borlänge)
Inventor: Fredrik Moberg (Saltsjo-Boo)
Application Number: 14/006,365
International Classification: E01F 9/018 (20060101);