HELMET

Abstract

A helmet (100) including an impact absorbing layer (102), an outer shell (104) and a connector (106, 114). The outer shell is mounted on the outer surface of the impact absorbing layer. The connector connects the outer shell to the impact absorbing layer, to retain the outer shell on the impact absorbing layer. The connector is also arranged to allow the outer shell to separate from the impact absorbing layer when the helmet is subject to an impact.

Claims

1. A helmet comprising: an impact absorbing layer; an outer shell mounted on the outer surface of the impact absorbing layer; and a connector which connects the outer shell to the impact absorbing layer to retain the outer shell on the impact absorbing layer; wherein the connector is arranged to allow the outer shell to separate from the impact absorbing layer when the helmet is subject to an impact.

2. The helmet as claimed in claim 1, wherein the impact absorbing layer comprises a hollow cell structure.

3. The helmet as claimed in claim 1, wherein the outer shell is formed from a rigid material.

4. The helmet as claimed in claim 1, wherein the outer shell has a thickness of less than 6 mm, less than 4 mm, e.g. less than 2 mm, e.g. less than 0.5 mm.

5. The helmet as claimed in claim 1, wherein the connector is arranged to allow the outer shell to separate from the impact absorbing layer when the helmet is subject to an impact having a particular force.

6. The helmet as claimed in claim 1, wherein the connector is located along an axis of symmetry of the helmet.

7. The helmet as claimed in claim 1, wherein the connector is located at the front of the helmet.

8. The helmet as claimed in claim 1, wherein the connector comprises a discrete component from the outer shell and the impact absorbing layer.

9. The helmet as claimed in claim 1, wherein at least a portion of the connector is arranged to detach from the impact absorbing layer and/or the outer shell when the helmet is subject to an impact.

10. The helmet as claimed in claim 1, wherein the connector comprises a plug which extends between the outer shell and the impact absorbing layer.

11. The helmet as claimed in claim 10, wherein the outer shell comprises an aperture for receiving the plug.

12. The helmet as claimed in claim 10, wherein the connector comprises a socket for receiving the plug of the connector.

13. The helmet as claimed in claim 12, wherein the socket is formed on or attached to the outer surface of the impact absorbing layer.

14. The helmet as claimed in claim 12, wherein the plug and the socket attach together via a push fit.

15. The helmet as claimed in claim 10, wherein the plug comprises an outer head having dimension(s) greater than the corresponding dimension(s) of the aperture.

16. The helmet as claimed in claim 1, wherein the connector comprises a projection and that is integral to the impact absorbing layer, wherein the protection is attached to the main body of the impact absorbing layer by a flexible portion.

17. (canceled)

18. The helmet as claimed in claim 16, wherein the impact absorbing layer comprises a cavity arranged to receive the projection.

19. The helmet as claimed in claim 16, wherein the outer shell comprises an aperture for receiving the projection.

20. The helmet as claimed in claim 1, wherein the impact absorbing layer comprises at least one groove formed therein, wherein the outer shell comprises at least one inwardly projecting ridge, and wherein the at least one ridge is arranged to engage with the at least one groove when the outer shell is mounted on the impact absorbing layer, and wherein the at least one ridge and the at least one groove are arranged such that a particular force is required to remove the at least one ridge from the at least one groove.

21. (canceled)

22. The helmet as claimed in claim 1, wherein the connector extends in a radial direction to the impact absorbing layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0053] An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0054] FIG. 1 shows a front exploded view of a helmet according to an embodiment of the present invention;

[0055] FIG. 2 shows a rear exploded view of the helmet shown in FIG. 1;

[0056] FIG. 3 shows a front view of the helmet shown in FIGS. 1 and 2;

[0057] FIG. 4 shows a cross-section view of the helmet shown in FIGS. 1, 2 and 3;

[0058] FIG. 5 shows a front view of the helmet shown in FIGS. 1 to 4 during an oblique impact;

[0059] FIGS. 6A, 6B and 6C show a selection of views of a plug for use in the helmet; and

[0060] FIG. 7 shows a cross-section view of a portion of a helmet according to another embodiment of the present invention.

DETAILED DESCRIPTION

[0061] A helmet acts to protect a user's head from injury by absorbing energy from an impact. Oblique impacts, which are a common type of impact, may subject a helmet to significant tangential forces. Such forces have the potential to cause rotational acceleration of the user's brain, which may cause serious brain injuries. Embodiments of the present invention aim to provide an improved helmet that seeks to mitigate the effect of such oblique impacts.

[0062] FIGS. 1 to 5 show different views of a helmet 100 according to an embodiment of the present invention. Both FIGS. 1 and 2 show an exploded view of the helmet to demonstrate the different components of the helmet 100 clearly. FIG. 1 shows a view directed towards the front of the helmet 100. FIG. 2 shows a view directed towards the back of the helmet 100. The helmet 100 has the following principal components: an impact absorbing layer 102, an outer shell 104 and a plug 106.

[0063] The impact absorbing layer 102 is predominately formed of an out-of-plane honeycomb structure. The impact absorbing layer 102 further comprises a rim 108 around the base of the helmet 100. The rim 108 is formed from a solid (e.g. non-hollow) material such as expanded polystyrenes in contrast to the out-of-plane honeycomb structure 102 which formed of hollow cells, the tessellating cells having a hexagonal cross section.

[0064] The rim 108 of the impact absorbing layer 102 further includes a set of grooves 116, into which ridges 118 on the lower edge of the outer shell 104 (as can be seen in FIG. 2) fit. These interlocking grooves 116 and ridges 118 help to retain the outer shell 104 in position on the impact absorbing layer 102 during normal use. FIG. 2 also shows an additional protrusion 124 on the impact absorbing layer 102 mounted on the rear of the helmet. The protrusion 124 interconnects with a corresponding recess 126 on the outer shell 104, and further helps to retain the outer shell 104 in position on the impact absorbing layer 102 during normal use.

[0065] As can be seen from FIG. 1, a socket 114 is attached to the outer surface of the impact absorbing layer 102 into which the plug 106 fits. The plug 106 and the socket 114 fit together via a push (e.g. friction) fit. Together, the plug 106 and the socket 114 form a connector that connects the impact absorbing layer 102 and outer shell 104 together to retain the outer shell 104 on the impact absorbing layer 102 during normal use.

[0066] The outer shell 104 includes an aperture 110 at the front of the helmet through which the plug 106 can be inserted when the outer shell 104 is positioned on the impact absorbing layer 102. To fit together the plug 106, the outer shell 104 and the impact absorbing layer 102, the outer shell 104 is first positioned on the impact absorbing layer 102. This involves interlocking the side grooves 116 and corresponding complementary ridges 118, as well as the rear protrusion 124 and the interconnecting recess 126.

[0067] When the outer shell 104 is correctly positioned on the impact absorbing layer 102, the aperture 110 in the outer shell 104 is aligned with the socket 114. The plug 106 can then be inserted through the aperture 110 and into the socket 114. A front view of the helmet 100, with the plug 106 inserted and holding the outer shell 104 in position, is shown in FIG. 3. FIG. 4, which shows a cross section view of the helmet 100 in a plane along the central axis of symmetry of the helmet 100, shows the plug 106 in position extending through the outer shell 104 and into the socket 114 on the impact absorbing layer 102.

[0068] FIG. 3 also shows recesses 122 in either side of the inner surface of the outer shell 104. In FIG. 5, the corresponding protrusions 120 on the outer surface of the impact absorbing layer 102 are seen, as well as the recesses 122 in the outer shell 104. When the outer shell 104 is positioned correctly on the impact absorbing layer 102, the protrusions 120 fit into the recesses 122, acting to help locate and retain the outer shell 104 on the impact absorbing layer 102.

[0069] FIG. 5 demonstrates the reaction of the helmet 100 shown in FIGS. 1 to 4 in an oblique impact. In FIG. 5 the helmet 100, which is attached to the head of a user who is falling downwards, has been subject to a collision with the obstacle 502. The edge of the obstacle 502 which the helmet 100 contacts during the collision is slanted, and contacts the helmet 100 at a position which is offset from the centre of the helmet 100, which results in the force exerted on the helmet from the impact having a significant tangential component.

[0070] In the impact shown in FIG. 5, the force exerted upon the helmet 100 during the impact is larger than the particular force which is required to detach the plug 106 from the socket 114, so to allow the outer shell to separate from the impact absorbing layer 102. Therefore, upon impact with the obstacle 502, the plug 106 is ejected from the helmet 100; specifically ejected from the socket 114 on the impact absorbing layer 102. As seen in FIG. 5, the plug 106 completely separates from the helmet 100. However, there may be other embodiments not shown in which the plug 106 remains in contact with at least part of the helmet 100 whilst still allowing the outer shell 104 to separate from the impact absorbing layer 102.

[0071] Upon impact with the obstacle 502, the interconnecting recesses 122 and protrusions 120, the interconnecting grooves 116 and ridges 118, and the interconnecting protrusion 124 and recess 126 also become disconnected from each other. There are therefore no remaining features which connect the outer shell 104 to the impact absorbing layer 102. The outer shell 104 is then able to rotate on the impact absorbing layer 102. This rotation is caused by the tangential component of the force exerted on the helmet 100 upon impact with the obstacle 502. The outer shell 104 rotating independently of the impact absorbing layer 102 (and ultimately the head of the user) reduces the rotation of head of the user, which may reduce the injuries sustained from the impact.

[0072] The Applicant has found that helmets according to embodiments of the present invention may reduce the rotational acceleration and velocity experienced the head of a user, compared to conventional foam helmets, by approximately 25% (in rotational acceleration) and approximately 45% (in rotational velocity).

[0073] FIGS. 6A, 6B and 6C show various views of the plug 106. As can be seen in these Figures, the plug 106 comprises an outer head 602. The outer head 602 has an area greater than that of the aperture 110 into which the plug fits. After insertion of the plug 106 through the aperture 110 and into socket 114, the outer head 602 sits outside of the outer shell 104 as seen in FIG. 3.

[0074] The plug 106 further comprises a neck 604, which is connected to the outer head 602. In examples in which the plug 106 and the socket 114 fit together via a push (e.g. friction) fit, the neck 602 may be made from a deformable plastic such that the neck 602 of the plug 106 can be inserted into the socket 114. The neck 604 has ridges 606 which act to hold the plug 106 in position in the socket 114. The socket may comprises corresponding grooves which mate with the ridges 606 of the plug 106 when the plug 106 is inserted into the socket.

[0075] FIG. 7 shows a cross-sectional view of a portion of a helmet 700 according to another embodiment of the present invention. The helmet 700 has the following principal components: an impact absorbing layer 702, an outer shell 704 and a latch 706. The latch 706 may be positioned in a similar location as the plug shown in previous figures.

[0076] The latch 706 is integral to (e.g. formed from the same material as) the impact absorbing layer 702. The latch 706 includes a flexible portion 708 that attaches the latch 706 to the main body of the impact absorbing layer 702. The flexible portion acts as a living hinge to allow the position of the latch 706 to change relative to the main body of the impact absorbing layer 702 and the outer shell 704. The latch 706 also includes a block tip 707.

[0077] The impact absorbing layer 702 additionally includes a cavity 714. When a force is applied to the latch 706, the flexible portion 708 bends, which may move the latch 706 into the cavity 714.

[0078] The outer shell 704 includes an aperture 705. During normal use (e.g. not during an accident), the latch 706 extends through the aperture 705. The block tip 707 of the latch 706 helps to keep the outer shell 704 in position on the impact absorbing layer 702 during normal use, by interacting with the edges of the aperture 705 to prevent translational movement of the outer shell 704 with respect to the impact absorbing layer 702.

[0079] Upon impact with an obstacle (e.g. similar to that seen in FIG. 5), the force of the impact acts on the flexible portion 708 of the latch 706, causing the flexible portion 708 to bend. The direction in which the flexible portion 708 is bent may depend on the direction of the tangential forces acting on the helmet upon impact.

[0080] In an impact in which the tangential forces act in the direction shown by arrow 730, i.e. the impact force acts downwards, as the outer shell 704 rotates downwards it moves over the latch 706 and the latch 706 is pushed into the cavity 714. This allows the outer shell 704 to detach from and move over the impact absorbing layer 702, helping to reduce the tangential forces transferred to the head of the user.

[0081] In an impact in which the tangential forces act in the direction shown by arrow 740, i.e. the impact force acts upwards, as the outer shell 704 rotates, the edge of aperture 705 of the outer shell 704 engages against the block tip 707 of the latch 706. The force exerted on the latch 706 either moves the latch 706 into the cavity 714, or rotates the latch 706 away from the cavity 714 and back on itself. Either of these movements of the latch 706 allows the outer shell 704 to detach from and/or move obstruction free over the impact absorbing layer 702, helping to reduce the tangential forces transferred to the head of the user.

[0082] In an impact in which the tangential forces act in another direction to that shown by arrows 730, 740, both of the abovementioned mechanisms may occur (e.g. at least in part) in order to enable the separation of the outer shell 704 and the impact absorbing layer 702.

[0083] In general, the latch 706 shown in FIG. 7, is able to maintain its functionality after an impact. For example, in an impact in which the latch 706 is merely compressing into the cavity 714 such that the outer shell 704 can move freely on the impact absorbing structure 702, after the impact the original (or a new) outer shell 704 may be repositioned on the impact absorbing structure 702.

[0084] The latch 706 may also be manually compressed into the cavity 714 by a user, e.g. to allow for easy intentional removal the outer shell 704. This may allow the outer shell 704 to be interchangeable, for example for aesthetic purposes.

[0085] Thus it will be appreciated by those skilled in the art that a helmet according to embodiments of the present invention, in which two independent layers (the outer shell and impact absorbing layer) connected by a connector, which allows the layers to separate when the helmet is subject to an impact, helps to reduce the tangential forces that may be transferred from an oblique impact to the head of the user. This may provide significant benefits over known helmets, e.g. in helping to reduce brain injuries. It will further be appreciated however that many variations of the specific arrangements described herein are possible within the scope of the invention. For example, a different type of connector (as opposed to a plug and socket and arrangement) may be provided to connect the outer shell to the impact absorbing layer.