Protective Helmet

• US 20080066217A1
• Filed: 07/13/2005
• Published: 03/20/2008
• Est. Priority Date: 07/13/2004
• Status: Active Grant

• Current Assignee: KU Leuven Research & Development
• Original Assignee: KU Leuven Research & Development
• Inventors: Perre, George, Lierde, Carl, Auderkercke, Remy, Sloten, Jos, Verpoest, Ignace, Haex, Bart, Depreitere, Bart, Goffin, Jan
• Granted Patent: US 7,930,771 B2
• Time in Patent Office: Days
• US Class Current: 2/412
• CPC Class Codes: A42B 3/064 with relative movement between layers
• CPC Class Codes: A42B 3/124 with at least one corrugated or ribbed layer
• CPC Class Codes: A42B 3/128 with zones of different density

Abstract

A protective helmet is described comprising: an outer layer (1); an inner layer (5) for contact with a head of a wearer; and an intermediate layer (3, 4) comprising an anisotropic cellular material comprising cells having cell walls, the anisotropic cellular material having a relatively low resistance against deformation resulting from tangential forces on the helmet. The anisotropic material can be a foam or honeycomb material. The foam is preferably a closed cell foam. The helmet allows tangential impacts to the helmet which cause less rotational acceleration or deceleration of the head of the wearer compared to helmets using isotropic foams while still absorbing a significant amount of rotational energy.

Claims

1-12. -12. (canceled)

13. A protective helmet comprising:

an outer layer;

an inner layer for contact with a head of a wearer; and

an intermediate layer comprising an anisotropic foam material comprising cells having cell walls, the anisotropic foam material having a relatively low resistance against deformation resulting from tangential forces on the helmet.

14. A helmet according to claim 13, wherein the anisotropic foam material is a closed cell foam.

15. A helmet according to claim 13, wherein deformation properties of the anisotropic material depend on orientation of cells forming the anisotropic material.

16. A helmet according to claim 13, wherein deformation properties of the anisotropic material depend on wall thickness of cells forming the anisotropic material.

17. A helmet according to claim 13, comprising two layers of anisotropic material, the two layers having different anisotropic properties.

18. A helmet according to claim 17, wherein a first of said two layers of anisotropic material has a direction of easiest deformation which is different from a direction of easiest deformation of the second of the two anisotropic layers.

19. A helmet according to claim 13, wherein the intermediate layer is further arranged to absorb energy in a direction normal to the helmet.

20. A helmet according to claim 13, wherein the outer layer comprises a material which is arranged, in use, to distribute forces acting on the helmet over a larger surface.

21. A helmet according to claim 20, wherein the outer layer comprises a polycarbonate or fibre-reinforced plastics layer.

22. A helmet according to claim 13, comprising a first further layer which is arranged, in use, to absorb part of the impact energy.

23. A helmet according to claim 22, wherein there are first and second further layers, the first further layer being formed of a material which is softer than a material used for the second further layer.

24. A helmet according to claim 22, wherein the first further layer comprises polyurethane foam or polystyrene.

25. A helmet according to claim 23, wherein the first further layer comprises polyurethane foam or polystyrene.

26. A helmet according to claim 14, wherein deformation properties of the anisotropic material depend on wall thickness of cells forming the anisotropic material.

27. A helmet according to claim 14, comprising two layers of anisotropic material, the two layers having different anisotropic properties.

28. A helmet according to claim 27, wherein a first of the two layers of anisotropic material has a direction of easiest deformation which is different from a direction of easiest deformation of the second of the two layers of anisotropic layers.

29. A helmet according to claim 14, wherein the intermediate layer is further arranged to absorb energy in a direction normal to the helmet.

30. A helmet according to claim 14, wherein the outer layer comprises a material which is arranged, in use, to distribute forces acting on the helmet over a larger surface.

31. A helmet according to claim 14, comprising a first further layer which is arranged, in use, to absorb part of the impact energy.

32. A helmet according to claim 31, wherein there are first and second further layers, the first further layer being formed of a material which is softer than a material used for the second further layer.