WO2007042930A1

WO2007042930A1 - Helmet

Info

Publication number: WO2007042930A1
Application number: PCT/IB2006/002866
Authority: WO
Inventors: Christopher James Leatt; Grant Leigh Nelson; Mark Eric Hopkins
Original assignee: Leatt Brace Holdings (Pty) Ltd.
Priority date: 2005-10-14
Filing date: 2006-10-13
Publication date: 2007-04-19
Also published as: EP1933656B1; ATE447866T1; BRPI0618410A2; HK1120708A1; DE602006010418D1; CN101340829A; EP1933656A1; ES2338462T3; US20110004980A1; CN101340829B

Abstract

A helmet (10) is provided, that has a first resilient shell (12), a support structure (16,18) inside the first shell to support the first shell on the wearer's head (14), a chin strap (20), to hold the helmet in position, a deformable layer (24) on the outside of the first shell and a tough outer shell (26) on the outside of the deformable layer. The deformable layer is of a material that absorbs energy when it is deformed and returns slowly to its original shape afterwards. The helmet includes a chin bar (34) with two opposing ends (36) that are displaceable relative to the outer shell, immediately inwardly of the outer shell. The outer profile of the helmet has a plurality of generally planar surfaces (28) and the helmet has a rear strap (38) that is attachable to the chin strap and that is configured to extend around the back of the wearer's head.

Description

HELMET

FIELD OF THE INVENTION

THIS INVENTION relates to helmets.

BACKGROUND TO THE INVENTION

Helmets for protecting a wearer's head against injuries are typically either of a "full face" or an "open face" configuration, including a tough, resilient shell, typically of a composite material or had plastic, a thick layer of polystyrene foam and a fabric lining, often with thin, soft padding for comfort.

Helmets known as "full face" helmets are commonly worn on the head as a precaution against head injuries in activities such as motor sport and typically include a shell that extends generally around the wearer's head, except for the face, and a so-called "chin bar" that extends across the lower part of the wearer's face. The chin bar is typically integrally formed with the shell and is spaced from the wearer's mouth and nose, to allow him to breathe easily.

When full frontal impact occurs on the chin bar of a full face helmet, the impact is transferred via the helmet's attachment to the wearer's head to the base of his skull and a shear force is exerted on the upper cervical spine. These shear forces often result in devastating injury to the base of the skull and/or the cervical spine. Similarly, when impacts occur on any part of a helmet, the impact is transferred via the shell and polystyrene foam to the skull of the wearer and causes injury to the skull and/or the upper cervical spine. Decelerating brain injury can occur as a result of deceleration of the helmet. Further, the outer shape of the shells are typically rounded, with the result that the helmet tends to perform a rolling action upon impact with most surfaces, which rolling action is transferred to the neck of the user or is resisted by the neck of the user, causing further loading and probable injury to the upper cervical spine.

Helmets are typically held in position on the wearer's head as a result of the complementally shaped concave inside of the helmet and a chin strap that extends around the jaw of the wearer. However, in impact, especially frontal impact, the helmet tends to rotate forward and often, rotates off the rear of the wearer's head, exposing the rear of the wearer's head or the entire head, to injury.

In the event of an accident in which the neck of the injured person may have been injured, the neck is often stabilised by fitting a neck brace. However, in instances, as typically occurs in motor sport, where the patient is wearing a helmet, it may be difficult or impossible to fit a neck brace without moving the head or neck, which in turn increases the risk of neck injury. It is likewise also very risky to attempt to remove the helmet from the patient's head, since this may also result in movement which could cause or exacerbate injury. The object of the present invention is to provide a helmet that can ameliorate the risk of injury in the event of impact.

BRIEF DESCRIPTION OF THE INVENTION

According to the present invention there is provided a helmet comprising: a first resilient shell, shaped to extend generally around the head of a wearer; a support structure disposed inside the first shell and configured to support the first shell on the wearer's head; and at least one chin strap, attachable to the first shell and configured to extend around the jaw of the wearer, to hold the helmet in position; wherein the helmet includes a deformable component disposed on the outside of the first shell, said deformable component being of a material that absorbs energy when being deformed.

The term "strap" is to be understood to include any flexible element, capable to transferring tensile loads and includes, but is not limited to a length of high strength fabric.

The deformable component may be in the form of a layer extending around the first shell, at least in part and the component may be of a material that returns slowly to its original shape after being deformed, i.e. a material with so-called "memory". The helmet may include a tough outer shell on the outside of the deformable layer.

The helmet may include a deformable chin bar with two opposing ends that may be disposed adjacent the outer shell at lateral locations, the chin bar being disposed at a position corresponding to the wearer's jaw and the ends of the chin bar being displaceable relative to the outer shell, e.g. the ends of the chin bar may be disposed immediately inwardly of the outer shell, so that it can slide inside the outer shell.

The outer profile of the helmet may define a plurality of generally planar surfaces.

The helmet may include a rear strap that is attachable to the chin strap and that is configured to extend around the head of the wearer, generally below the posterior occipital protuberance of the wearer. Preferably, the chin strap and the rear strap are configured such that tension applied to the chin strap places the rear strap under tension, e.g. the rear strap could be attachable to the chin strap.

The helmet may include an inflatable neck brace, configured to extend around the neck of the wearer, at least in part and the neck brace may be attached to the helmet, or may be an accessory that is fitted around the neck of the wearer when required, e.g. in the event of an accident. BRIEF DESCRIPTION OF THE DRAWINGS

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

Figure 1 is a sectional side view of a helmet in accordance with the present invention; and

Figure 2 is three-dimensional view of the first shell, outer shell, chin bar and neck brace of the helmet of Figure 1.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to the drawings, a helmet in accordance with the present invention is generally indicated by reference numeral 10.

The helmet 10 includes a first or inner shell 12 of resilient material such as fibreglass, carbon fibre or a suitable plastics material, similar to the outer shell of a conventional helmet and shaped to extend generally around the head 14 of a wearer. Inside the inner shell 12, the helmet 10 includes a support structure in the form of a layer of polystyrene foam 16 and padding 18, also similar to that found in a conventional helmet, to support the shell 12 on the head 14. In order to keep the helmet 10 on the head 14, it includes a chin strap 20 that is attached to the shell 12 by rivets 22, that can be joined by releasable clips (not shown) and that can extend around the jaw of the wearer. On the outside of the shell 12, the helmet has an impact absorbing component in the form of a layer 24, covered by a tough outer shell or skin 26. There are a number of materials that would be suitable for use in the absorbing layer 24 and the skin 26, but in order to be most effective, the material in the absorbing layer should deform readily under impact while absorbing as much energy from the impact as possible, but should not return to its original shape immediately, as the reactive forces this could create could increase the risk of injury to the upper cervical spine of the wearer. Instead, the material in the impact absorbing layer 24 should return to its shape slowly, as is typically the case with materials with so-called "memory". Some examples of materials suitable to be used in the impact absorbing layer 24 are expanded elastomers, such as expanded polyurethanes.

The material for the outer shell or skin 26 should preferably be flexible enough not to limit the deformation of the impact absorbing layer 24 too much during impact, but should be durable enough to resist wear during normal use of the helmet 10. One example of a suitable material for the skin 26, would be a polyethylene.

The outer profile of the impact absorbing layer 24 and the skin 26, is shaped to form a number of surfaces 28 that are each generally planar. These surfaces 28 are disposed at locations on the helmet 10 where it is most likely, according to tests, to receive an impact during an accident. The purpose of the planar surfaces 28 is to resist rolling of the helmet 10 during impact and thus to limit loading and possible injury on the wearer's neck or upper cervical spine. The helmet 10 defines a face aperture 30 that corresponds to the position of the wearer's face and that is recessed laterally in the region of the wearer's eyes to improve lateral vision and defines a neck aperture 32 in the underside of the helmet, corresponding to the position of the wearer's neck. A part of the inner shell 12 extends across the position of the wearer's jaw, between these two apertures 30, 32.

The helmet 10 further includes a resiliently deformable, elongate, curved chin bar 34 that extends on the outside of the inner shell 12 in a position that corresponds generally with that of the wearer's jaw, so that the helmet generally resembles a full face helmet. The chin bar 34 comprises an impact absorbing layer 24 and outer skin 26, in the same way as the remainder of the helmet 10, but the ends 36 of the chin bar are not fixedly attached to the rest of the skin 26 and are displaceable relative to the rest of the skin.

In the illustrated embodiment of the invention, the ends 36 extend immediately on the insides of the rest of the skin 26, so that they can slide inside the skin in case of impact on the chin bar 34, while the impact absorbing layer 24 is being deformed under the impact. In other embodiments of the invention, other impact absorbing structures may be used to connect the chin bar 34 to the rest of the skin 26, e.g. a dampened piston mechanism that is configured to absorb energy during impact and to return the chin bar to its original position slowly after impact. The helmet 10 includes a rear strap 38 that is attached to the chin strap 20 and that extends around the back of the head 14, slightly below the posterior occipital protuberance 40. By "attached" is meant that the rear strap 38 is structurally connected to the chin strap 20, e.g. the rear strap can be connected to the inner shell 12 by the same rivets 22 as the chin strap. However, in a preferred embodiment of the invention, as shown in the drawings, the rear strap 38 is attached to the chin strap itself, so that when the chin strap is placed under tension, it pulls on the rear strap which is also placed under tension, thus improving its grip on the posterior of the head 14.

The helmet 10 includes an inflatable neck brace 42 that can form in incomplete ring, when inflated, which can extend around the neck of the wearer, to stabilise the neck. The incomplete ring shape of the neck brace 42 defines a gap 44 that can preferably be positioned at the front, thus allowing access to the wearer's throat.

The neck brace 42 can be worn as part of the helmet 10, extending generally around the neck aperture 32 in a deflated condition, to be inflated only when required, or can be kept separately, to be placed in position around the wearer's neck in a deflated condition when required and to be inflated. When the neck brace is inflated, it stabilises the wearer's neck by inhibiting movement of the helmet 10 closer to wearer's body on all sides. This aspect of the invention holds the advantages that it is either in position at all times that the helmet 10 is worn, or it allows the neck brace to be placed in position while deflated, in which condition it has small dimensions and is flexible enough not to require movement of the wearer in order for it to be positioned.

In use, the helmet 10 is worn in the conventional manner, with the chin bar 34 in its normal position, as shown in the drawings. In the event of a frontal impact on the chin bar 34, e.g. in the event of a collision, the chin bar is rapidly displaced rearward under the impact while its ends 36 slide rearward inside the skin 26, but the impact is not directly transferred to the inner shell 12 as in the case of a conventional helmet. Instead, the impact is reduced by the absorption of energy in the impact absorbing layer 24. A reduced impact is thus transferred to the inner shell 12, which in turn is transferred via the polystyrene layer 16 and padding 18 to the head 14, thus reducing the risk of injury to the skull and cervical spine.

After the impact, the chin bar 34 returns slowly to its normal position as the impact absorbing layer 24 returns to its original shape, thus allowing the helmet 10 to be removed from the head 14 with ease, allowing the user to breathe freely, etc.

Likewise, in the event of impact on the helmet 10 from other directions, the skin 26 and impact absorbing layer 24 are deformed and while doing so, energy from the impact is absorbed in the impact absorbing layer and a reduced impact is transferred to the. inner shell 12. After the impact, the impact absorbing layer 24 returns slowly to its original shape. In the event that the helmet 10 tends to rotate forward during impact, the rear strap 38 grips the head 14 below the posterior occipital protuberance 40 and is prevented from sliding upwards by the protuberance, so that it inhibits further forward rotation of the helmet. This action of the rear strap 38 is enhanced by its attachment to the chin strap 20. In the event that the helmet 10 tends to rotate forward, this places the chin strap 20 under tension, which places the rear strap 38 under tension so that it pulls more tightly against the posterior of the head 14 and has better grip to prevent it from sliding upwards over the posterior occipital protuberance 40 and thus to prevent the helmet from rotating off the head.

The helmet 10 holds a number of advantages, mentioned above, but in particular, the structure of the helmet including the tough outer skin 26 and the impact absorbing layer 24, allows it to function over a wide range of decelerations, i.e. impact speeds, to reduce the risk of decelerating brain injury.

Claims

1. A helmet (10) comprising: a first resilient shell (12), shaped to extend generally around the head (14) of a wearer; a support structure (16,18) disposed inside the first shell and configured to support the first shell on the wearer's head; and at least one chin strap (20), attachable to the first shell and configured to extend around the jaw of the wearer, to hold the helmet in position; characterised in that the helmet includes a deformable component (24) disposed on the outside of the first shell, said deformable component being of a material that absorbs energy when being deformed.

2. A helmet (10) as claimed in claim 1 , characterised in that said deformable component (24) is in the form of a layer extending around the first shell (12), at least in part.

3. A helmet (10) as claimed in claim 1 or claim 2, characterised in that said deformable component (24) is of a material that returns slowly to its original shape after being deformed.

4. A helmet (10) as claimed in any one of the preceding claims, characterised in that the helmet includes a tough outer shell (26) on the outside of

the deformabie component (24).

5. A helmet (10) as claimed in claim 4, characterised in that the helmet includes a deformable chin bar (34) with two opposing ends (36) that are disposed adjacent the outer shell (26) at lateral locations, the chin bar being disposed at a position corresponding to the wearer's jaw and the ends of the chin bar being displaceable relative to the outer shell.

6. A helmet (10) as claimed in claim 5, characterised in that the ends (36) of the chin bar (34) are disposed immediately inwardly of the outer shell (26).

7. A helmet (10) as claimed in any one of the preceding claims, characterised in that the outer profile of the helmet defines a plurality of generally planar surfaces (28).

8. A helmet (10) as claimed in any one of the preceding claims, characterised in that the helmet includes a rear strap (38) that is attachable to the chin strap (20) and that is configured to extend around the head (14) of the wearer, generally below the posterior occipital protuberance (40) of the wearer.

9. A helmet as claimed in claim 8, characterised in that the chin strap (20) and the rear strap (38) are configured such that tension applied to the chin strap places the rear strap under tension.

10. A helmet (10) as claimed in claim 9, characterised in that the rear strap (38) is attachable to the chin strap (20).

11. A helmet (10) as claimed in any one of the preceding claims, characterised in that the helmet includes an inflatable neck brace, configured to extend around the neck of the wearer, at least in part.