WO1996026654A9

WO1996026654A9 - Helmet and/or helmet shell and method for making

Info

Publication number: WO1996026654A9
Application number: PCT/US1996/002280
Authority: WO
Filing date: 1996-02-27
Publication date: 1996-11-28

Abstract

A helmet (10) in accordance with the present invention includes an outer shell (12) and an inner part (20). The outer shell (12) has first (14), second (16), and third (18) layers which are secured together with the first (14) and third (18) layers made from an impact resistant material and the second layer (16) made from a first shock absorbent material which has a continous, polymeric matrix. Preferably, the first (14) and third (18) layers are made from ABS and the second (16) layer is made from expanded ABS. The inner part (20) is secured to the third layer (18) and is made from a second shock absorbent material. The helmet (10) is made by first heating a sheet which has first, second, and third layers laminated together for a first set time at a first temperature. When the sheet is at the first set temperature, a helmet-shaped ram is pressed into the sheet to form a cavity defined by the third layer.

Description

HELMET AND/OR HELMET SHELL AND METHOD FOR MAKING

FIELD OF THE INVENTION

This invention relates generally to a helmet and more particularly to a helmet and/or helmet shell and a method for making the helmet and/or helmet shell with an outer shell having a first, second, and third layers secured together, with the first and third layers made from an impact resistant material and the second layer made from a shock absorbent material which has a continuous, expanded polymeric matrix.

BACKGROUND OF THE INVENTION

Typically, helmets which have been designed to satisfy safety standards have been constructed in three parts. The first part is an outer shell which is only designed to be impact resistant and is made from a rigid material, such as plastic. The second part is a middle layer which is only designed to be shock absorbent and is made from a hard compressed foam, such as polystyrene, which has a density ranging between 30 oz/ft³ and 12 lbs/ft³. Typically, the middle layer is manufactured by first expanding the polystyrene pellets and then compressing the pellets together. The resulting middle layer is brittle and crumbles easily because there is no interlocking between the polystyrene pellets (i.e. the layer is not a continuous matrix). The third part is an inner layer which is only designed to make the helmet comfortable to wear and is made from a soft padding material, such as a fit foam. Fit foam is a foam having a low density, typically ranging between 14 oz/ft³ - 48 oz/ft³. The inner layer is necessary, because the middle layer is too rigid and thus to uncomfortable to wear directly against the head.

Each of the three parts is manufactured separately and then assembled together. Generally, each part has a manufacturing tolerance of about +/- 4%. As a result, when the parts are assembled together, air gaps are located between each set of two parts. Typically, a prior art helmet with three parts has a cross-sectional width of about 1 V." . A few helmets have included a fourth part which is a second shell located between the middle and inner layers. Helmets which include the fourth part are designed for special applications, such as riot helmets. Like the first part, the fourth part is only designed to be impact resistant and is made from a rigid material, such as plastic. The fourth part adds to the cross-sectional width of these prior helmets. Although most of these helmets are able to satisfy current helmet safety standards, they have a number of problems. When these prior helmets are assembled together, the three or more parts and air gaps between each part make these helmets bulky, posing safety risks to the wearers. In particular, the large size of these helmets makes them more likely to snap backwards when a blow strikes the helmet, increasing the chances of whiplash. Additionally, the size of the helmets makes them more likely to rotate on the user's head when they are struck, increasing the chances for rotational injuries to the neck and spine. Further, these prior helmets often do not sufficiently absorb and attenuate the resulting impact of the blow. As a result, even with the prior helmets in place, serious head injuries occur.

SUMMARY OF INVENTION

A helmet in accordance with the present invention has a top, front, opposing sides and back portion and defines an inner cavity adopted to receive and protect an individual's head. The helmet includes an outer shell and an inner part. The outer shell includes first, second, and third layers which are all secured together. The first and third layers are made from an impact resistant material and the second layer is made from a first shock absorbent material which has a continuous, expanded polymeric matrix. The inner part is made from a second shock absorbent material and is secured to the third layer in the inner cavity.

The helmet is made by heating a sheet comprising first, second and third layers which are secured together. Once the sheet is heated, a helmet-shaped ram is pressed into the first, second, and third layers to form the inner cavity. The sheet is allowed to cool and then the helmet-shaped ram is withdrawn from the first, second, and third layers. Finally, the sheet is cut circumferentially around the inner cavity to form an outer shell. Meanwhile, the inner part is formed by cutting a second sheet into one or more sections and then securing each section to the third layer.

The helmet provides a number of advantages over prior helmets. Specifically, the helmet rests much closer to the wearer's head then prior helmets, because the cross-sectional width of the helmet is less than the cross-sectional width of prior helmets. This reduction in cross-sectional width and thus overall bulk for the helmet is achieved without sacrificing any protection to the wearer's head. By bringing the helmet closer to the wearer's head, the risk of whiplash and rotational injuries is reduced, because, when the helmet is struck with a blow, the helmet is not as bulky and, thus, is not as likely to snap backwards to cause whiplash or to rotate causing rotational damage to the neck or spine. Part of the reduction in the cross-sectional width and, thus, bulk of the helmet is achieved by eliminating the air gaps commonly found between the parts in prior art helmets and eliminating the need for padding on the inside of the helmet. The air gaps are eliminated by using a laminate of the first, second, and third layers which are deformed together to form the outer shell so that no air gaps could be located between the layers. The padding can be eliminated, because, unlike the middle layer in prior helmets which is made from a hard compressed foam which is uncomfortable to wear directly against the wearer's head, the inner part has a density similar to muscle tissue making it comfortable to wear.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a helmet in accordance with the present invention;

FIG. 2(a) is a side view of a helmet in accordance with the present invention with a detachable side guard which is detached from the second helmet;

FIG. 2(b) is a side view of the helmet shown in FIG. 2(a) with the detachable side guard partially attached; FIG. 2(c) is a side view of the helmet shown in FIG. 2(a) with the detachable side guard fully attached;

FIG. 2(d) is a perspective, bottom view of the helmet shown in FIG. 2(a) illustrating an alternative embodiment for the inner part of the helmet; FIG. 3 is a perspective, bottom view of a helmet in accordance with the present invention with a chin harness;

FIG. 4(a) is a cross-sectional view of a helmet in accordance with the present invention with a flexible neck guard;

FIG. 4(b) is a back view of the helmet of FIG. 4(a) with the neck guard; and FIG. 5 is a cross-sectional view of another helmet in accordance with the present invention.

DETAILED DESCRIPTION

A helmet 10 in accordance with the present invention is illustrated in FIG. 1 and includes an outer shell 12 with first, second, and third layers 14, 16, and 18, respectively, and an inner part 20. Outer shell 12 and inner part 20 are designed to absorb and attenuate any blows to helmet 10 to reduce the chances of head injuries. Helmet 10 provides a number of advantages over prior helmets, including a reduction in the cross-sectional width of helmet 10 without sacrificing any protection. Bringing helmet 10 closer to the wearer's head reduces the risk of whiplash and rotational injuries, because, when helmet 10 is struck with a blow, helmet 10 is not as bulky and, thus, is not as likely to snap backwards causing whiplash or to rotate causing rotational damage to the neck or spine. Additionally, reducing the cross- sectional width and, thus, the size or bulk of helmet 10 along with the use of inner part 20 which has a density similar to muscle tissue makes helmet 10 more comfortable to wear than prior helmets.

Referring more specifically to FIG. 1, a cross-sectional view of helmet 10 with outer shell 12 and inner part 20 is illustrated. First, second, and third layers 14. 16, and 18 are secured together and inner part 20 is secured to third layer 18. In this particular embodiment, first, second, and third layers 14, 16, and 18 are laminated together, although other means of securing layers 14, 16, and 18 together could be used. First and third layers 14 and 18 are made from an impact resistant material which has a continuous, polymeric matrix, such as ABS which has a density of about twenty- three lbs/ft³. Second layer 16 is made from a first shock absorbent material and impact resistant material which has a continuous, expanded polymeric matrix. In this particular embodiment, second layer 16 is made from expanded ABS. Typically, second layer 16 has a density ranging between 1.5 lbs/ft³ and 45 lbs/ft³. In this particular embodiment, a laminate of first, second, and third layers 14, 16, and 18, sold under the brand name Royale-X® by Uniroyal Technology located in Mishawaka, IN, is used to form outer shell 12 for helmet 10.

Since first, second, and third layers 14, 16, and 18 for outer shell 12 are laminated together before being deformed into outer shell 12, no air gaps are found between layers. Eliminating the air gaps between each layer 14, 16, and 18 helps to reduce the cross-sectional width of helmet 10, enabling helmet 10 to be brought close to the wearer's head without sacrificing any protection. Bringing helmet 10 closer to the wearer's head reduces the chances of whiplash and rotational injuries. In this particular embodiment, outer shell 12 and innerpart 20 have a total cross-sectional width of about ⁷/β", while a prior helmet which would provide the same amount of protection to the wearer's head would have a cross-sectional width of about 1%".

Inner part 20 is manufactured separately from outer shell 12 and is secured to third layer 18 of outer shell 12 by glue or any other means, such as rivets. Inner part 20 is made from a second shock absorbent material and is designed to have a foam density similar to that of muscle tissue so that inner part 20 can be comfortably worn against the individual's head. Typically, inner part 20 will have a density between 1.5 lbs/ft³ and 45 lbs/ft³. In this particular embodiment, inner part 20 is made from foam sold under the brand names as Confor-45® or Confor-47® by E-A-R Specialty Composites located in Ind., IN, although other types of shock absorbent materials could be used. Although in FIG. 1 inner part 20 only has one section, inner part 20 can be constructed to have two or more different sections 20(l)-20(5) which are secured to and positioned around third layer 18 of outer shell 12, as shown in FIG. 2(d).

Helmet 10 is effective in attenuating and absorbing the force of a blow to diffuse the amount of force transmitted to the wearer's head. When helmet 10 is struck with a blow, first layer 10 attenuates the impact, second layer 16 absorbs and attenuates the impact, third layer 18 further attenuates the impact, and inner part 20 again absorbs and attenuates the impact. As a result, by the time the force of the blow is transmitted to the individual's head, the blow is substantially, if not completely, dissipated.

Referring to FIG. 5, a cross-sectional view of a helmet 70 with a fourth layer 19 is illustrated. Corresponding elements in FIG. 5 have numeral designations which correspond to those used in FIG. 1 and thus will not be described here again. Fourth layer 19 is secured to the outer surface of first layer 14. In this particular embodiment, fourth layer 19 is made from a fiberglass material, although other material such as ABS could be used. Fourth layer 19 adds another impact resistent layer to helmet 70 to provide further protection to the user's head.

To manufacture helmet 10 illustrated in Fig. 1 , first a sheet of first, second, and third layers 14, 16, and 18 laminated together is obtained and then is cut to get a sheet which can be used to form outer shell 12.

A frame (not shown) is secured around the edges of the sheet and the frame is moved by a conveying system (not shown) into an oven (not shown) and is heated. The particular temperature and amount of time the sheet is heated can vary as long as the sheet is heated to a point where the sheet can be deformed. When the sheet is sufficiently heated, then the sheet is withdrawn from the oven by the conveying system. The sheet in the frame is positioned by the conveying system under a helmet- shaped ram (not shown). The particular shape of the ram varies depending upon the type of helmet being manufactured. With this method, all types of helmets can be manufactured, including riding, football, hockey, and baseball helmets. Once the sheet is in position, then the helmet-shaped ram is pressed into the center of the heated sheet to form a cavity defined by third layer 18. The helmet-shaped ram is held in place until the sheet cools and then the ram is withdrawn from the sheet. Once the helmet-shaped ram is removed, then the sheet is allowed to cool further. Once the sheet has cooled, the frame is removed from the sheet.

Next, the sheet is secured within a cutting machine, and a circumferential cut around the cavity in the sheet is made to cut out outer shell 12. The edges of outer shell 12 may be sanded to remove any burrs. Outer shell 12 may then be painted, fitted with a fabric cover, such as velvet, as shown in FIG. 3, or otherwise finished.

While outer shell 12 is being manufactured, inner part 20 can also be manufactured. In this particular embodiment, a piece of shock absorbent foam is cut by a clicker die (not shown) to form inner part 20 for each outer shell 12. As shown in FIGS. 1 and 2(d), inner part 20 may be in one section 20 or in multiple sections

20(l)-20(5). Once inner part 20 is cut out and outer shell 12 is formed, then inner part 20 is secured by glue, rivets, or any other means desired to third layer 18 as shown in FIGS. 1 and 2(d). The process for manufacturing the other helmets 24, 36, 56, and 70 is the same as for helmet 10 and thus will not be described. FIGS. 2(a-c), illustrate side views of a helmet 24 in accordance with the present invention with a detachable side guard 26 for ear protection. As shown in FIG. 2(a), detachable side guard 26 has an ear opening 28 and an optional material 30 secured along an upper and trailing edge of side guard. In this particular embodiment, material 30 is a flexible material, such as nylon, although other types of materials could be used. Four parts of four snaps 32(a) are secured at locations along flexible material 30 and are capable of engaging with the matching four parts for the four snaps 32(b) which are secured in helmet 24 along a side, bottom edge 34. Although four snaps 32 are shown to secure side guard 26 to the side of helmet 24, other devices, such as velcro could be used to secure detachable side guard 26 to the side of helmet 24 if desired. Additionally, detachable side guard 26 may be secured directly to the side of helmet 24 without material 30. Referring to FIG. 2(b), one of the four snaps 32 is secured to partially connect detachable side guard 26 to the side of helmet 24. Referring to FIG. 2(c), all four snaps 32 have been secured to fully attach detachable side guard 26 to the side of helmet 24. Although detachable side guard 26 is only shown on one side of helmet 24, detachable side guards 26 could be attached to both sides of helmet 24. Referring to FIG. 3, a perspective view of a helmet 36 with U-shaped harnesses 38 and 40, such as those disclosed in U. S. Design Patent No. 299,766 to Friedson and herein incorporated by reference, are illustrated. Helmet 36 includes a fabric cover 42 which surrounds first layer 14 of outer shell 12. In this particular embodiment, fabric cover 42 is made from velvet, although other types of material could be used. Helmet 36 also includes an optional head band 43 which is secured around the inner rim of helmet 36. In this particular embodiment, head band 43 is made from silk although other materials, such as cotton, could be used.

One U-shaped harness 38 is secured on one side of helmet 36 and the other U-shaped harness 40 is secured to the opposite side of helmet 36. Each end 44(a-b) and 46(a-b) of each harness 38 and 40 has an optional elastic member 48 secured to the ends by stitching 50 or any other type of securing means desired, such as staples. Optional elastic members 48 are then secured to a bottom, side edge of helmet 36. Alternatively, ends 44(a-b) and ends 46(a-b) could be secured to the bottom, side edges of helmet 36. Once elastic member 48 are secured to helmet 36 then U-shaped harnesses 38 and 40 are positioned to extend down below the bottom of helmet 36 and around or below the ears of an individual wearing helmet 36. A chin strap 52 made from another elastic member is secured and extends between the bottom of each U-shaped harness 38-40. With elastic members 48 and chin strap 52 made from another elastic member, less pressure is put on the throat of the wearer, allowing the wearer to talk more easily while still safely retaining helmet 36 on the wearer's head.

Referring to FIG. 4(a), a cross-sectional view of a helmet 56 with a neck guard 58 and a face guard 60 is illustrated. A piece of flexible material 62 is secured along one upper edge of neck guard 58 and along a lower, back edge of helmet 56 by rivets 64. Although rivets are used to secure flexible material 62 to neck guard 58 and to helmet 56, other securing means, such as velcro® or snaps, could be used. In this particular embodiment, neck guard 58 is made from the same material as outer shell 12 and has a width of about two inches, although the material used and the width can vary as desired. Referring to FIG. 4(b), a back view of helmet 56 with neck guard 58 in place is illustrated. With neck guard 58 in place, the wearer's head is protected from blows to the head and neck covered by helmet 56 and neck guard 58. Flexible material 62 allows the neck guard 58 to move separately from helmet 56 in a hinge-like fashion permitting neck guard 58 and, thus, the wearer's head to tilt backwards without jamming the wearer's neck, therefore reducing neck and spinal injuries.

FIGS. 4(a-b) also illustrate a face guard 60 for helmet 56. Face guard 60 is secured by two rivets 66 along the front, bottom edge of helmet 56. Face guard 60 extends down from the front, bottom edge of helmet 56 and protects the wearer's face from blows. In this particular embodiment, face guard 60 is made from a clear polycarbonate material. The particular width, means for securing, and the type of material used for make face guard 60 can vary as desired. Additionally, other types of face guards 60, such as football masks could be used.

Having thus described the basic concept of the invention, it will be readily apparent to those skilled in the art that the foregoing detailed disclosure is intended to be presented by way of example only, and is not limiting. The various alterations, improvements and modifications will occur and are intended to those skilled in the art, though not expressly stated herein. These modifications, alterations and improvements are intended to be suggested hereby, and are within the spirit and scope of the invention. Accordingly, the invention is limited only by the following claims and equivalence thereto.

Claims

WHAT IS CLAIMED IS:

1. A helmet shell having a top, front, opposing sides, and back portion and defining an inner cavity adapted to receive and protect an individual^'s head, wherein i the helmet shell comprises an outer shell having first, second, and third layers secured together wherein said third layer defines the inner cavity adapted to receive and protect an individual's head, said first and third layers made from an impact resistant material and said second layer made from a first shock absorbent material which has a continuous, expanded polymeric matrix.

2. The helmet shell according to Claim 1 further comprising an inner part secured to said third layer and made from a second shock absorbent material.

3. The helmet shell according to Claim 1 wherein said impact resistant material has a continuous, polymeric matrix.

4. The helmet shell according to Claim 1 wherein said second layer has a density between 1.5 lbs/ft³ and 45 lbs/ft³.

5. The helmet shell according to Claim 4 wherein said first and third layers are made from an acrylonitrile-butadiene-styrene copolymer and said second layer is made from an expanded acrylonitrile-butadiene-styrene copolymer.

6. The helmet shell according to Claim 2 wherein said inner part has a density between 1.5 lbs/ft³ and 45 lbs/ft³.

7. The helmet shell according to Claim 2 wherein said inner part comprises two or more sections secured to different portions of said third layer.

8. The helmet shell according to Claim 1 further comprising a fourth layer made from the impact resistent material secured to said first layer.

9. The helmet shell according to Claim 1 further comprising at least one side guard detachably secured to one side of the helmet, and positioned to extend down over one ear of the individual's head.

10. The helmet shell according to Claim 1 further comprising: a first and second U-shaped harnesses each with a pair of ends, wherein each end has a first elastic member secured to said end and said ends for the first harness are each secured on one side of the helmet, while the ends of the second harness are secured to an opposite side of the helmet so each said first and second harness extends down below the ears on each side of the individual's head; and a second elastic member connecting the bottom of said pair of harnesses.

11. The helmet shell according to Claim 1 further comprising: a neck guard having an upper edge; one or more sections of flexible material, each said section of flexible material secured to said upper edge of said neck guard and to the back portion of the helmet.

12. The helmet shell according to Claim 1 further comprising: a face guard secured to the front of the helmet, said neck guard extending down to protect at least a portion of the individual's face.

13. A method for making a helmet comprising the steps of: heating a sheet comprising a first layer which is secured to a second layer, said first layer made from an impact resistant material and said second layer made from a first shock absorbent material which has a continuous, expanded polymeric matrix; deforming said heated sheet with a helmet-shaped ram to form a cavity defined by the second layer; cooling said sheet; withdrawing said helmet-shaped ram from said cavity in said sheet; and cutting said sheet around said cavity to form an outer shell.

14. The method as set forth in Claim 13 wherein said second layer has a density between 1.5 lbs/ft³ and 45 lbs/ft³.

15. The method as set forth in Claim 13 wherein said first layer is made from acrylonitrile-butadiene-styrene copolymer and said second layer is made from expanded acrylonitrile-butadiene-styrene copolymer.

16. The methods as set forth in Claim 13 wherein said impact resistant material has a continuous, polymeric matrix.

17. The method as set forth in Claim 13 wherein said sheet has a fourth layer made from the impact resistent material secured to said first layer.

18. The method as set forth in Claim 13 further comprising: cutting an inner part from a second shock absorbent material; and securing said inner part to said second layer proximate to said cavity.

19. The method as set forth in Claim 18 further comprising: cutting said inner part into two or more sections and securing the sections to different portions of the second layer.

20. The method as set forth in Claim 16 further wherein said sheet has a third layer between said second layer and said inner part, wherein said third layer is made from said impact resistant material.

21. The method as set forth in Claim 20 wherein said sheet has a fourth layer made from the impact resistent material and secured to said first layer.

22. The method as set forth in Claim 20 wherein said third layer is made from an acrylonitrile-butadiene-styrene copolymer.

23. The method according to Claim 20 further comprising: cutting an inner part from a second shock absorbent material; and securing said inner part to said third layer proximate to said cavity.

24. The method according to Claim 23 further comprising: cutting said inner part into two or more sections and securing the sections to different portions of the third layer.

25. A method for making a helmet comprising the steps of: heating a sheet comprising first, second, and third layers which are secured together, said first and third layers made from an impact resistant material and said second layer made from a first shock absorbent material which has a continuous, expanded polymeric matrix; deforming said heated sheet with a helmet-shaped ram to form a cavity defined by the third layer; cooling said sheet; withdrawing said helmet-shaped ram from said cavity in said sheet; and cutting said sheet around said cavity to form an outer shell.

26. The method as set forth in Claim 25 wherein said second layer has a density between 1.5 lbs/ft³ and 45 lbs/ft³.

27. The method as set forth in Claim 25 wherein said first and third layers are made from acrylonitrile-butadiene-styrene copolymer and said second layer is made from expanded acrylonitrile-butadiene-styrene copolymer.

28. The method as set forth in Claim 25 wherein said impact resistant material has a continuous, polymeric matrix.

29. The method according to Claim 25 further comprising: cutting an inner part from a second shock absorbent material; and securing said inner part to said third layer proximate to said cavity.

30. The method according to Claim 29 further comprising: cutting said inner part into two or more sections and securing the sections to different portions of the third layer.

31. The method as set forth in Claim 25 wherein said sheet has a fourth layer made from the impact resistent material and secured to said first layer.