US20240260702A1

Movatterモバイル変換

Info

Publication number: US20240260702A1
Application number: US18/562,740
Authority: US
Inventors: Farid Golnaraghi; Adrian WIKARNA
Original assignee: Shield X Technology Inc
Current assignee: Shield X Technology Inc
Priority date: 2021-05-18
Filing date: 2022-05-18
Publication date: 2024-08-08

Abstract

An apparatus and method for reducing tangential acceleration of a head with a helmet having a sheer release layer between the helmet and the head of the user. The release layer includes a low-friction surface against another surface such that the helmet shell acceleration does not translate to equal acceleration of the layer immediately adjacent to the head of the user. Coatings and materials are disclosed as well as padding and attachment materials and methods.

Description

PRIORITY CLAIMS

This application is a U.S. national phase of International Patent Application No. PCT/CA2022/050788 filed May 18, 2022; which claims priority from Canada Patent Application No. 3120169, filed May 28, 2021. This International Patent Application No. PCT/CA2022/050788 filed May 18, 2022, is a continuation-in-part of U.S. application Ser. No. 17/323,397, filed May 18, 2021, the contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present disclosure details improvements to protective headgear and, more specifically, to a sheer release layer for integration or securement to headgear such as to the interior of a helmet. The sheer release reduces rotational acceleration felt by the brain during an impact to an outside surface of protective headgear.

BACKGROUND OF THE INVENTION

Studies have shown that rotational forces on the head are a major source of concussions in an impact scenario. As such, designers have proposed headgear that, in addition to absorbing normal forces, reduces the tangential component of an impact to a head. U.S. Pat. No. 10,143,255 (Golnaraghi, et. al.) describes a danger of injuries occurring to a head of a person wearing protective headgear due to rotational acceleration. The reason for this is that, upon impact, an outer shell of the protective headgear stops instantly, not allowing the head to keep moving. Stopping the human skull too quickly tends to cause concussions. A solution proposed by Golnaraghi et. al. is to provide an impact diverting mechanism that includes a top layer attached to the shell of the helmet and a bottom layer attached to the liner of the helmet. The top layer is disposed adjacent to and mechanically connected to the bottom layer. Upon impact, the top layer shifts and stretches relative to the bottom layer. The sliding and stretching dissipates kinetic energy.

Golnaraghi et. al. further describes embodiments that have an intermediate layer positioned between the top layer and the bottom layer. The intermediate layer may include a liquid-gel lubricant to facilitate relative slipping movement of the top layer and the bottom layer. As research in this area continues, there have been various structures proposed that include an intermediate layer to facilitate relative slipping movement of the top layer and the bottom layer. U.S. Patent publication 20130040524 (Halldin et al) titled “Intermediate Layer of Friction Decreasing Material” proposes the use of fibers as friction decreasing material.

SUMMARY OF THE INVENTION

In a first embodiment of the invention a protective liner includes a liner body having a padding layer and a low-friction layer. The padding layer faces the body of the user, such as the head, elbow, knee, or shoulder. The padding layer may also provide impact absorption, especially from normal forces. The padding layer provides comfort to the user interface, such as padding and breathability. It is preferably covered with a thin fabric.

The low-friction layer is preferably positioned outwardly from the padding layer relative to the user's body. This layer is either positioned under or outside a layer of fabric (or other material). For example, a top fabric layer is positioned over the low-friction (i.e., slippery) layer in one preferred embodiment. In such an embodiment, the low-friction layer is an intermediate layer that overlies and is secured to the padding layer positioned on the bottom of the intermediate layer, such as with a helmet. The top fabric layer overlies the intermediate layer. The top fabric layer has a perimeter and a central portion. The top fabric layer is preferably secured on the perimeter leaving the central portion of the top fabric layer free to accommodate relative sliding movement of the intermediate layer.

The top fabric layer embodiment provides some distinct advantages. The slippery intermediate layer slides freely on fabric. Even when the fabric is secured at the perimeter, the central portion of the fabric still accommodates sliding movement of the slippery intermediate layer. In one preferred embodiment, a limited movement of 5 mm to 15 mm is sufficient to dissipate a significant amount of the kinetic energy and reduce rotational acceleration of the head to much safer levels in many instances.

If a greater range of sheer movement is desired to dissipate more kinetic energy in an intended application, there are a number of ways that this can be accommodated. For example, one could use a stretchable top fabric layer, such that the top fabric layer facilitates increased sliding movement over the slippery intermediate layer.

There are immediate benefits in the use of the helmet liner, as summarized above. The helmet liners that use the liquid-gel lubricant are more difficult and more expensive to manufacture. More things can go wrong with helmet liners that use the liquid-gel lubricant. If the seal confining the liquid-gel lubricant is compromised, the liquid-gel lubricant will leak out or the liquid-gel lubricant will dry out when exposed to air. In either event, movement of the top layer in relation to the bottom layer is adversely affected.

In one preferred embodiment, the protective liner is a helmet liner attached to an interior surface of a helmet (such as a bicycle or motorcycle helmet) through the use of hoop-and-loop fasteners, commonly known by the trademark brand name VELCRO®. This attachment can be simplified when the top fabric layer can serve as a loop portion of a hook-and-loop fastener and mates with a hook portion of the hook-and-loop fastener secured to the top fabric layer. In some embodiments, the use of hook-and-loop fasteners improves the sheer release performance of the helmet liner when the top fabric layer serves as the loop portion of the hook-and-loop fastener. The hook portion anchors the top fabric layer, which tends to localize the impact force (thus the sliding motion) and also ensures the sliding motion happens optimally in specific locations on the liner.

In another preferred embodiment the low-friction material is held on a body material with the low-friction layer facing the user. The low-friction layer in such embodiment preferably includes a low-friction coating or surface treatment. In one embodiment, the low-friction layer is positioned beneath a liner material that interfaces with the body of the user. The liner material, such as a liner having an open-cell foam covered in a thin fabric, bears against the user's body on one side and bears directly or indirectly against the low-friction material on the other side. The low friction material is preferably positioned between such liner and an impact shell, such as a helmet shell or other impact shell such as an elbow, knee, or shoulder guard. A further impact layer, such as a closed-cell foam layer (e.g., expanded polystyrene (EPS)) can be positioned between the low-friction layer and the shell. Furthermore, a body with further padding or a support layer can be positioned between the low-friction layer and the shell and/or further impact layer.

Thus, the low-friction layer reduces rotational acceleration during an impact to an outside surface of protective gear, such as headgear. The body having the low-friction layer is positioned between a head of a person and an inside surface of protective headgear. The body has a first face and a second face, with the first face providing a slippery exterior surface. The method involves positioning the second face of the body against one of the head or the inside surface of the protective headgear, with the slippery exterior surface on the first face engaging the other of the head or the inside top surface of the protective headgear. Upon impact, a sliding movement and material stretching along the slippery exterior surface takes place between the head of the user and the inside top surface of the protective headgear engaging along the slippery exterior surface. Thus, the rotational acceleration of the head of the user is reduced.

Likewise, if the arrangement of the slippery surface between a shell and user is employed on other protective gear, damage to impact points on the body is reduced. Thus, for example, an elbow or knee may be less likely to abraded or broken.

Those familiar with the prior art might appreciate that the method described above is a marked departure from the teachings of the prior art. The sheer-release body does not have a top layer and a bottom layer that slide relative to each other. There is no intermediate sliding layer to assist relative movement of the top layer and the bottom layer. Instead, the body has a slippery exterior surface and facilitates movement to dissipate kinetic energy using this slippery exterior surface.

There will hereinafter be described a series of alternative embodiments that demonstrate alternative ways of implementing the apparatus and method using a slippery exterior surface. In a first embodiment, the low-friction layer slides under a layer of fabric secured about the low-friction layer. In another embodiment, the body is secured to the inside surface of the protective headgear and the head of a person slides along the slippery exterior surface. In a further embodiment, the inside surface of the protective headgear slides along the slippery exterior surface. In still another embodiment, a helmet liner (with the head of a person positioned within it) slides along the slippery exterior surface.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:

FIG.1 is a schematic diagram illustrating the forces involved in an impact on a protective headgear common to all disclosed embodiments;

FIG.2 is a top plan view of a helmet liner;

FIG.3 is a partial side-elevational view, in section, of a first embodiment illustrating sheer between the protective gear and the user;

FIG.4 is a partial side-elevational view, in section, of another embodiment showing the basic common components;

FIG.5 is a partial side-elevational view showing a sheer-release body secured to protective gear;

FIG.6 is a partial side-elevational view, in section, of another embodiment using the body ofFIG.4; and

FIG.7 is a partial side-elevational view, in section, of another embodiment using the body ofFIG.4.

DETAILED DESCRIPTION

FIG.1 illustrates the force vectors acting upon protective gear when an impact occurs. The primary focus of the present invention is the tangential component of the force. Protective gear that has long been available having compressible layers, such as crushable EPS foam, addresses the normal forces to some extent. The present invention principally addresses increased protection for the tangential component of impact forces while also adding some additional protection from normal forces in some embodiments. The tangential forces are addressed with various arrangements of a low-friction layer sandwiched with various other layers between the user and the shell of a piece of protective gear.

A helmet liner identified byreference numeral10, will now be described with reference toFIGS.2 and3. As one can appreciate fromFIG.2, the liner may be formed to fit any particular piece of protective gear, such as a helmet. Liner fingers (or other shapes) can be arranged to follow the particulars gear, such as along the inner ridges of a vented bicycle helmet, for example.

As shown inFIG.3,helmet liner10 has aliner body12 with multiple layers. When viewed in section, it can be seen thatliner body12 has an impact absorbingbottom layer15, a low-friction (“slippery”)intermediate layer17, and a topmoveable layer19.Moveable layer19 is preferably fabric but could alternatively be another layer, such as a thin elastomer layer with properties that allow it slide freely onintermediate layer17. Fabric of various materials has been found to provide the right properties to create a low-friction interface between low-friction interface withintermediate layer17. In this preferred embodiment, slipperyintermediate layer17 overlies and is secured tobottom layer15.Top fabric layer19 overlies slipperyintermediate layer17.

Referring toFIG.3,top fabric layer19 has aperimeter21 and acentral portion23. If secured at all,top fabric layer19 is secured to eitherbottom layer15, slipperyintermediate layer17, or both preferably only at locations alongperimeter21. The securement can be all along the perimeter or just at intermittent locations along the perimeter. This leavescentral portion23 oftop fabric layer19 free to accommodate relative sliding movement of slipperyintermediate layer17. In order to suit most applications, a sliding movement of at least 5 mm should be achieved. Some fabrics are inherently more “slippery” and more readily accommodate sliding movement than other fabrics. The selection of the fabric material fortop fabric layer19 can, therefore, impact performance. Where increased sliding movement is desired, a stretchable fabric material may be selected fortop fabric layer19. This enablestop fabric layer19 to facilitate increased sliding movement of slipperyintermediate layer17 astop fabric layer19 stretches.

Referring toFIG.3, it is preferred thattop fabric layer19 be capable of serving as a loop portion of a hook-and-loop fastener. Ahook portion26 of the hook-and-loop fastener mates to the fabric for the purpose of connecting to aninterior surface32 of ahelmet30.

An ideal material fortop layer19, such as a fabric, is slippery on the intermediate layer, provides the desired amount of movement, and is capable of serving as a loop portion of a hook-and-loop fastener. Nylon and spandex blended fabrics as well as polyester and spandex blended fabrics provide beneficial results. Various materials are suitable for impact absorbingbottom layer15, such as a polymer foam and, more particularly, an open-celled polymer foam such as an EVA foam. Certain elastic materials and auxetic materials would also be suitable. Various materials are suitable for slipperyintermediate layer15. The preferred material is a polymer plastic and, more particularly, a thermoplastic.

Referring toFIG.3, to increase comfort, asecond fabric layer25 is adhered tobottom layer15 for direct contact with a human head.Second fabric layer25 is for the comfort of the wearer and increases the durability of the liner by protecting the open-cell foam ofbottom layer15. Otherwise,second fabric layer25 does little to contribute to performance ofhelmet liner10 in the event of an impact.

Referring toFIG.3,helmet30 represents a typical piece of protective gear.Helmet30 is shown as a single layer in the schematic view ofFIG.3. However, it will be a layered construction such as in known in the art and may include a hard outer shell with an inner layer of crushable foam such as a closed-cell polystyrene foam. Thehelmet30 can have additional layer or layers such as fabric or other impact absorbing materials. For our purposes, all such layers are represented byhelmet30 ofFIG.3.

In the event of an impact having a tangential component, the exterior surface or shell will immediately accelerate opposite the direction of impact due to the frictional sheer forces applied to the shell. Depending on the construction ofhelmet30, including the sheer properties of the materials of construction, theinterior surface32 ofhelmet30 will accelerate along with the shell in a direction indicated byarrow27. Thus, if the helmet is initially moving and impacts a non-moving surface or object (e.g., the ground, pavement, a rock, etc.) it can come to an abrupt stop upon impact with the non-moving surface.

An acceleration force will likewise be applied to ahead40 of a wearer in the direction indicated byarrow27. However,helmet liner10 helps to protect thehead40 of wearer by dissipating kinetic energy such thathead40 does not experience the same degree of acceleration (i.e., impact).Top fabric layer19 is anchored tointerior surface32 ofhelmet30 byhook portion26 of a hook-and-loop fastener, which engagestop fabric layer19. As previously described,top fabric layer19 serves as the loop portion of the hook-and-loop fastener. Impact absorbingbottom layer15 with attached slipperyintermediate layer17 abut directly or indirectly againsthead40 of the wearer. However, there is relative sliding movement between slipperyintermediate layer17 andtop fabric layer19. This results in slipperyintermediate layer17 moving relative to head40 such that the acceleration ofhead40 is less than that ofintermediate layer17. Thus,head40 is less likely to be concussed or incur other damage due to the impact forces being spread over a longer time interval (i.e., lower acceleration).

Helmet impact tests were performed using a guided free-fall oblique impact test rig dropping a helmet against an anvil at an impact angle of 45 degrees. The impact speed generated was 6.5 meters per second. A test was first conducted with a helmet having a standard helmet liner. This established a base line for comparing the performance of the helmet line described above. Tests were conducted in five impact locations and orientations: 1. front, 2. right side toward back, 3. left side toward back, 4. left side toward front, and 5. right side toward front. The rotational acceleration percentage reduction achieved byhelmet liner10 was as follows: 1. front an improvement of 22%, 2. right side toward back an improvement of 35%, 3. left side toward back an improvement of 6%, 4. left side toward front an improvement of 31% and 5. right side toward front an improvement of 45%. Note that in orientation #3 improvement gained was only 6%. The reason for this is believed to be due to the shape of the helmet tested, which created a geometric lock reducing the amount of motion possible.

Turning to another preferred embodiment,FIG.4 illustrates abody12. If only the tangential force were being addressed,body12 could consist only ofpolymer plastic portion14 with low-friction coating ortreatment22 and would not require impact absorbing properties. However, to providebody12 with additional impact-absorbing properties above that already provided byhelmet30 to address the normal component of the impact force, it is preferred thatbody12 include an open-celledpolymer foam portion16. The open-cell structure provides breathability and improved fit that can enhance comfort.Body12 has afirst face18 and asecond face20.First face18 providesbody12 with a slippery exterior surface. This can be accomplished by using a self-lubricating polymer plastic or, as illustrated here, by applying acoating22 to a hardpolymer plastic layer14. Other surface treatments may alternatively be used. As will hereinafter be further described,body12 is secured by mating hook-and-loop tape fasteners, having a hooktape fastener portion26 and a looptape fastener portion28. A looptape fastener portion28 is secured tosecond face20.

FIG.5 illustratesbody12 positioned between thehead40 of a person and aninside surface32 of the protective gear, in thisinstance headgear30.Second face20 ofbody12 is secured to insidetop surface32 ofprotective headgear30 by mating hooktape fastener portion26 secured to insidetop surface32 with looptape fastener portion28 secured tosecond face20.

When assembled as shown and described the slippery exterior surface onfirst face18 engageshead40. Upon impact, a sliding movement takes place relative to head40 along the slippery exterior surface onfirst face18.

At isolated locations where the hook-and-loop fasteners are placed, there is little or no motion relative tohelmet30. However, in areas where there are no hook-and-loop fasteners and the slippery exterior surface is in direct contact with the head or helmet surface, there is nothing stopping motion from occurring relative to the helmet shell. In some preferred embodiments, the slippery exterior surface will allow up to 15 mm of motion, which has proven to be enough to reduce the rotational acceleration of the head by up to 30%.

Although open-cellpolymer foam portion16 is preferred, other materials that are known for their impact absorbing properties could be substituted such as closed-cell foams, memory-foams, or other types of shock-absorbing foams. Although hardpolymer plastic layer14 is preferred for slippery exterior surface, other materials could be substituted and coated to provide the desired slippery surface, such as conventional thermoplastic, thermoset elastomers, natural or synthetic rubber, plasticized foams, low-density polyethylene, or high-density polyethylene. Preferred coating materials include a matte acrylic coating and a Teflon® (PTFE) coating. Although hook-and-loop tape fasteners are preferred, other types of mechanical fasteners could be used such as buttons, snap fasteners, stitching, adhesives, etc.

A further embodiment is illustrated inFIG.6

Body

12 is again positioned between thehead40 of a person and an insidetop surface32 ofprotective headgear30. In this embodiment,body12 serves as a helmet liner andsecond face20 ofbody12 is positioned against, but not necessarily secured to,head40.

When assembled as shown and described, the slippery exterior surface onfirst face18 engages insidetop surface32 ofprotective headgear30. Upon impact, the tangential force creates a sliding movement of insidetop surface32 sliding relative to the slippery exterior surface onfirst face18. It is to be noted thatbody12 is secured to insidetop surface32 ofprotective headgear30 by mating hooktape fastener portion26 secured to insidetop surface32 with looptape fastener portion28 secured tofirst face18. The idea is to securebody12 to a portion of insidetop surface32, such as an edge of a rib, which is not directly facinghead40 and allowing sliding to occur on that portion of insidetop surface32 that is directly facinghead40.

In another embodiment shown inFIG.7,body12 is again positioned between thehead40 of a person and an insidetop surface32 ofprotective headgear30. In this embodiment,second face20 ofbody12 is secured to insidetop surface32 ofprotective headgear30 by mating hooktape fastener portion26 secured to insidetop surface32 with looptape fastener portion28 secured tosecond face20. As with the embodiment described immediately above,body12 is secured to insidetop surface32 ofprotective headgear30 by mating hooktape fastener portion26 secured to insidetop surface32 with looptape fastener portion28. The idea is to securebody12 to a portion of insidetop surface32, such as an edge of a rib, which is not directly facinghead40 and allowing sliding to occur on that portion of insidetop surface32 that is directly facinghead40.

When assembled as shown and described, the slippery exterior surface onfirst face18 faceshead40 and engages therewith indirectly, by engaging withhelmet liner50 that is secured to head40. Upon impact, a sliding movement takes between head40 (along with helmet liner50) andfirst face18 by sliding along the slippery exterior surface onfirst face18.

The embodiments described above share the feature of a low-friction surface sliding in a layered configuration relative to a portion of a human body to be protected from excessive sheer forces causing tangential acceleration. The acceleration of the helmet upon impact is greater than that of the body part (e.g., head) being protected. Thus, the likelihood of injury is reduced.

The scope of the claims should not be limited by the illustrated embodiments set forth as examples but should be given the broadest interpretation consistent with a purposive construction of the claims in view of the description as a whole.

Claims

We claim:

1. Protective gear for reducing tangential acceleration of a body during an impact to a surface, the protective gear comprising:

an outer layer,

an inner layer,

an intermediate layer between the outer layer and the inner layer, the intermediate layer including a low-friction surface abutting the inner layer or the outer layer.

2. The protective gear ofclaim 1, further comprising an impact layer having impact absorbing properties to absorb energy from normal forces.

3. The protective gear ofclaim 2, wherein the impact layer comprises an open-celled polymer foam.

4. The protective gear ofclaim 1, wherein the low-friction surface comprises a polymer plastic layer.

5. The protective gear ofclaim 1, wherein the low-friction surface includes a low-friction coating on the intermediate layer.

6. The protective gear ofclaim 1, wherein a body includes the intermediate layer and an impact layer, the body being held in position within the outer layer by mechanical fasteners.

7. The protective gear ofclaim 6, wherein the mechanical fasteners are hook-and-loop tape fasteners.

8. The protective gear ofclaim 6, wherein the protective gear is a helmet and the body includes a first face being the low-friction surface and a second face positioned against an inside top surface of the helmet and a wearer's head slides along the slippery exterior surface on the first face.

9. The protective gear ofclaim 6, wherein the protective gear is a helmet and the body includes a first face being the low-friction surface and a second face of the body is positioned against the head and an inside top surface of the protective headgear slides along the slippery exterior surface on the first face.

10. The protective gear ofclaim 9, wherein the body is secured to a portion of the inside top surface that does not directly face the head, with sliding occurring on that portion of the inside top surface that is directly facing the head.

11. The protective gear ofclaim 9, wherein the body is a helmet liner.

12. The protective gear ofclaim 6, wherein the protective gear is a helmet and wherein a second face of the body is positioned against an inside top surface of the helmet and a helmet liner is position on the head and the head, covered by the helmet liner, slides along the low-friction surface of the intermediate layer.

13. The protective gear ofclaim 12, wherein the body is secured to a portion of the inside top surface that does not directly face the head, with sliding occurring on that portion of the inside top surface that is directly facing the head.

14. A method for reducing rotational acceleration during an impact to an outside surface of protective headgear, comprising:

positioning a body between a head of a person and an inside top surface of a protective headgear, the body having a first face and a second face, the first face providing a slippery exterior surface; and

positioning the second face of the body against one of the head or the inside top surface of the protective headgear, with the slippery exterior surface on the first face engaging the other of the head or the inside top surface of the protective headgear, such that, upon impact, a sliding movement takes place along the slippery exterior surface of the first face.

15. The method ofclaim 14, wherein the body has impact absorbing properties.

16. The method ofclaim 15, wherein the body is an open-celled polymer foam.

17. The method ofclaim 14, wherein the slippery exterior surface is a polymer plastic layer on the first face.

18. The method ofclaim 14, wherein the body is held in position within the protective headgear by mechanical fasteners.

19. The method ofclaim 18, wherein the mechanical fasteners are hook-and-loop tape fasteners.

20. The method ofclaim 14, wherein the second face of the body is positioned against the inside top surface of the protective headgear and the head slides along the slippery exterior surface on the first face.

21. The method ofclaim 14, wherein the second face of the body is positioned against the head and the inside top surface of the protective headgear slides along the slippery exterior surface on the first face.

22. The method ofclaim 21, wherein the body is secured to a portion of the inside top surface that does not directly face the head, with sliding occurring on that portion of the inside top surface that is directly facing the head.

23. The method ofclaim 21, wherein the body is a helmet liner.

24. The method ofclaim 14, wherein the second face of the body is positioned against the inside top surface of the protective headgear and a helmet liner is position on the head and the head, covered by the helmet liner, slides along the slippery exterior surface on the first face.

25. The method ofclaim 24, wherein the body is secured to a portion of the inside top surface that does not directly face the head, with sliding to occurring on that portion of the inside top surface that is directly facing the head.

26. A helmet liner for a helmet having a shell, the helmet liner comprising:

a liner body securable within the shell, the liner body comprising a low-friction layer and a fabric layer, the fabric layer abutting the low-friction layer, the fabric layer having a perimeter and a central portion, the central portion of the top fabric layer free to accommodate sliding movement relative to the low-friction layer.

27. The helmet liner ofclaim 26, further comprising an impact absorbing bottom layer secured to the low-friction layer.

28. The helmet liner ofclaim 27, wherein the fabric layer is secured on at least a portion of its perimeter to the low-friction layer.

29. The helmet liner ofclaim 26, wherein the fabric layer is stretchable, such that the fabric layer accommodates increased sliding movement of the low-friction layer as the fabric layer stretches.

30. The helmet liner ofclaim 26, wherein the fabric layer is capable of serving as a loop portion of a hook-and-loop fastener and mating with a hook portion of the hook-and-loop fastener for the purpose of being anchored to an interior surface of a helmet.

31. The helmet liner ofclaim 27, wherein the bottom layer is a polymer foam.

32. The helmet liner ofclaim 26, wherein the low-friction layer is a polymer plastic.