US20130340146A1

US20130340146A1 - Impact core for insertion inside an outer shell of a helmet

Info

Publication number: US20130340146A1
Application number: US13/990,672
Authority: US
Inventors: Lars Dekker; Rick Adriaan Keijzer
Original assignee: EGG International BV
Current assignee: EGG BV
Priority date: 2010-12-01
Filing date: 2011-12-01
Publication date: 2013-12-26
Also published as: NL2005798C2; EP2645894A1; WO2012074400A1

Abstract

The invention relates to an impact core for insertion inside an outer shell of a helmet. The impact core comprises a shock-proof material and is substantially dome-shaped having cut outs to increase the flexibility of the impact core. The cut out makes the impact core deformable and as a result the impact core can be adjusted according to different head shapes and sizes. The impact core comprises a substantially star-shaped cut out at a top and a plurality of elongated edge cut outs near an edge of said impact core. Further, each of a plurality of arms of said star-shaped cut out extends downward between two neighboring edge cut outs at the edge.

Description

FIELD OF THE INVENTION

The invention relates to helmets and, more particularly, to impact cores and safety helmets having an impact core.

BACKGROUND OF THE INVENTION

Typically, a safety helmet provides a user or a wearer protection from head injury or damage in case of an accident. There is a wide variety of safety helmets available in the market. Various examples of safety helmets may include, but are not limited to, bicycle helmets, motor bike helmets, and racing car helmets.
Different users may have different head sizes. Generally, a shopkeeper measures the size of the user's head with the help of a measuring instrument, and accordingly provides a helmet from the variety of helmets present in the shop. The user selects a helmet after taking numerous fitting trials depending on the ease and comfort of its fit.
However, the disadvantage associated with the abovementioned methods for selecting the best fit safety helmet is that only the size of the head is taking into.
Because apart from size, different users also have different head shapes, a helmet does not fit perfectly around the head. The user normally chooses a helmet that is comfortable but that does not fit perfectly. In fact, most often a helmet is chosen which is too spacious. This may lead to unnecessary injuries when being involved in an accident.
In light of the foregoing, there is a need for a comfortable fit safety helmet according to various head sizes and shapes of different users.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the invention to provide a helmet and/or an impact core that fits better on different heads as compared to the known helmets and/or impact cores.
In a first aspect, the invention relates to an impact core for insertion inside an outer shell of a helmet. The impact core comprises a shock proof material. The impact core is substantially dome-shaped and comprises cut outs. The cut outs increases the flexibility of the impact core. The impact core comprises a substantially star-shaped cut out at a top of said impact core and a plurality of elongated edge cut outs near an edge of said impact core. Each of a plurality of arms of said star-shaped cut out extends downward between two neighboring cut outs at the edge, or so called edge cut outs. Further, the flexible impact core can provide for a deformable and an adjustable helmet for different head shapes. The plurality of edge cut outs makes the impact core flexible.
In an embodiment, the star-shaped cut out is a cross-shaped cut out. For example, the cross may consist of two substantially perpendicularly crossing lines. Alternatively, the cross may for example comprise two lines crossing each other at an angle smaller than about 90 degrees.
It is noted that the arms of the star-shape may have substantially the same length. However, alternatively the length of the arms may differ from each other.
In an embodiment, the elongated cut outs near the edge extend from said edge in a substantially upward direction.
In an embodiment, each of the arms extends from the top of the impact core downwardly towards a respective point located above said edge, and wherein each of the elongated cut outs extends from the edge upwardly towards a respective point located below the top of the impact core.
In an embodiment, each arm extends downwardly to such extent that a lower part of the respective arm is at least partly located between two neighboring elongated edge cut outs.
In an embodiment, the impact core is substantially serpentine-shaped, following a substantially serpentine-shaped path extending in a circumferential direction of said impact core, the path running above upper ends of the elongated edge cut outs and running below lower ends of the arms. Accordingly, the serpentine-shaped impact core is deformable in different directions. Thus, the impact core deforms in different directions to adjust various head sizes and may provide the best fit helmet to the user.
In an embodiment, each of a plurality of arms of the star-shaped cut out extends vertically downward between two neighboring cut outs at the edge. With the word ‘downward’ is meant ‘towards the edge’ of the impact core. A combination of arms of a top cut out alternating with the edge cut outs, or so called bottom cut outs, can result in a serpentine-shaped impact core.
Preferably, the impact core is integrally formed. Advantageously, the material of the impact core is homogeneous.
In an embodiment, the impact core comprises expanded polypropylene. The expanded polypropylene is a multi-impact material and also flexible. The combination of the expanded polypropylene being flexible together with the cut outs, results in a deformable impact core. Since expanded polypropylene is a multi-impact material, it increases the durability of the helmet. Alternatively, the impact core is made from another flexible material or another flexible material composition.
In an embodiment, the impact core is produced using a moulding technique. The moulding technique can use a single mold which considerably reduces the manufacturing time and makes the overall process simple.
The invention further relates to a helmet comprising an impact core as described above. The helmet further comprises an outer shell, the impact core being arranged in said outer shell. Preferably, the helmet is a safety helmet.
In an embodiment, the outer shell of the helmet is made of acrylonitrile butadiene styrene (ABS). An outer shell of ABS material is impact resistant, and when it is not excessively thick, is also slightly flexible, which makes it a preferred material for the outer shell. Further, in a preferred embodiment, the outer shell has a thickness in the range of about 0.5 mm to about 3.5 mm, and more preferably in the range of about 1.8 mm to about 2.2 mm. The abovementioned thickness of the outer shell helps in achieving a deformity which results in expansion of the impact core to fit different head shapes. Additionally, it is easier to wear and remove the helmet with the abovementioned thickness of the outer shell. Instead of using ABS, alternative materials may be used for the outer shell, e.g. Polycarbonate.
In an embodiment, the helmet furthermore comprises a comfort core, and in a particular embodiment, the comfort core is substantially helmet-shaped layer arranged at least partly inside the impact core. The comfort core is made of Ethylene vinyl acetate (EVA) rubber. Also, the comfort core comprises an upper portion and a lower portion. The upper portion is substantially dome-shaped. The dome shape of the upper portion facilitates a base support to the impact core. Further, the lower portion surrounds a lower part of the skull of the user. In a particular embodiment, to provide a proper fit to the impact core when the comfort core is inserted in it, the upper portion of the comfort core is less thick than its lower portion.
It is noted that, in a preferred embodiment, the helmet comprises tree layers, substantially placed one inside the other. The three layered helmet may thus comprise: the outer shell, the substantially dome-shaped impact core substantially placed in said outer shell, and the comfort core arranged at least partly inside said impact core.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention and embodiments thereof will now be further elucidated by means of figures, wherein:

FIG. 1 schematically shows a representation of a helmet according to an embodiment of the present invention; and

FIGS. 2 a, 2 b, 2 c, 2 d, and 2 e depicts a top-view, a side-view, a front-view, a first perspective view, and a second perspective view, respectively, of the embodiment of FIG. 1.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 schematically shows a representation of an embodiment of a helmet 1 according to an aspect of the invention. The helmet comprises three layers—a comfort core 2, an impact core 3 according to an aspect of the invention, and an outer shell 4. The arrangement of the three layers of the helmet 1 is in a manner such that, the comfort core 2 can be arranged at least partly inside the impact core 3, and the impact core 3, along with the comfort core 2, can be arranged inside the outer shell 4.
It is noted that the helmet may be a so called safety helmet.
In an embodiment, the comfort core 2 is made of foam or expanded rubber, such as Ethylene vinyl acetate (EVA) rubber. In the embodiment of FIG. 1, the comfort core 2 is substantially a helmet-shaped layer and comprises an upper portion 5 and a lower portion 6. The upper portion 5 is substantially dome-shaped which facilitates a base support to the impact core 3. Thus, the impact core 3 gets the base support from the comfort core 2, and both are closely fit into the outer shell 4 of the helmet 1. Further, the lower portion 6 surrounds a lower part of the skull of a user. In a particular embodiment, the upper portion 5 is less thick than the lower portion 6 to properly accommodate the impact core 3.
Further, the outer shell 4 is preferably made of a shock-proof and a flexible thermoplastic, for example, acrylonitrile butadiene styrene (ABS). The flexible outer shell 4 easily accommodates the impact core 4 along with the partly fit comfort core 2. Further, the impact core 3 deforms easily when the outer shell 4 is flexible. In a particular embodiment, the outer shell 4 has a thickness in the range of about 0.5 mm to about 3.5 mm, and more preferably in the range of about 1.8 mm to about 2.2 mm. The outer shell 4 is preferably made thin, so that the outer shell 4 is deformable to fit different head shapes and sizes apart from being only strong. Additionally, the helmet 1 is easier to wear and remove from the head.
Furthermore, the second layer, i.e, the impact core 3 of the helmet 1 is substantially dome-shaped and comprises a shock-proof material. The shock-proof material in the impact core 3 makes the helmet 1 robust and protects the user in case of accidents. In an embodiment, the impact core 3 comprises a number of edge cut outs, or so called bottom cut outs, such as 7, 8, 9, and 10. It should be noted that four edge cut outs, i.e., 7, 8, 9, and 10 have been depicted in FIG. 1 only for exemplary purposes. However, the impact core 3 may have any multiple number of edge cut outs to provide proper fit to the different head shapes and sizes of the users, for example three or four edge cut outs.
Additionally, each of the edge cut outs 7, 8, 9, and 10 extends from the edge in a substantially upward direction. This is, each edge cut out 7, 8, 9, and 10 starts from an edge of the impact core 3. It may be apparent to any person skilled in the art that the edge may be defined as the circumferential boundary of the surface of the substantially dome-shaped impact core 3. It may be also appreciated by a person skilled in the art that the edge cut outs 7, 8, 9 and 10 provide sufficient space for expansion of the impact core 3 to adjust according to the different head shapes of different users.
FIGS. 2 a, 2 b, 2 c, 2 d, and 2 e depicts a top-view, a side-view, a front-view, a first perspective view, and a second perspective view, respectively, of the embodiment of FIG. 1.
FIG. 2 a depicts the top view of the impact core 3 of FIG. 1. In this embodiment, four cut outs 11, 12, 13, and 14 are arranged at top of the impact core 3. These cut outs 11, 12, 13, and 14 are slit-shaped and combine together to form a substantially star-shaped cut out at the top of the impact core 3 and can alternatively be referred to as the arms of the star-shaped cut out. Additionally, the impact core 3 comprises numerous other elongated cut outs, i.e. the edge cut outs 7, 8, 9, and 10 near the edge of the impact core 3 (as shown in FIG. 2 a). In this embodiment, the arms 11, 12, 13, and 14 of the star-shaped cut out extends vertically downward between two neighboring cut outs from the cut outs 7, 8, 9, and 10 at the edge. It should be noted that these cut outs will be collectively referred as 7-14 in the subsequent paragraphs.
It may be apparent to any person skilled in the art that, although the star-shaped cut out is cross-shaped in the shown embodiment, the star-shaped cut out can alternatively have another star-shape, and may for instance have three or five arms.
The cut outs 7-14 are of predefined length and width to provide maximum flexibility to the impact core 3. In the example of FIG. 2 a, the width of each of the slits 7-14 is about 10 mm. Furthermore, the pre-defined angle of separation between two subsequent cut outs at the edge 7 and 10 is preferably about 90 degrees. However, other angles of separation are possible, such as about 45, 72, 75 or 120 degrees. Typical dimensions of the impact core 3 are shown in FIG. 2 a. It is noted that other dimension are possible.
As will be appreciated by the skilled person, the edge cut outs may be evenly distributed around the impact core 3. However, the edge cut outs 7, 8, 9, and 10 may be placed closer to each other at a first part of the impact core than at another part of said impact core. For example, the angle of separation may be smaller at a back side than at a front side of said impact core, or vice versa.
As will be appreciated by the skilled person, the cut-outs can be of varying shapes, and the invention is by no means limited to the use of slit-shaped cut outs. It should however be noted that the cut-outs can not be too wide, since then, the protection of the head will be compromised.
FIGS. 2 b, 2 c, 2 d, and 2 e depict the side-view, the front-view, the first perspective view, and the second perspective view, respectively, of the impact core 3. As shown in FIGS. 1, 2 a, 2 b, 2 d, and 2 e, the arm 12 of the star-shaped cut out extends vertically downward between two neighboring cut outs 7 and 8 at the edge. The combination of the top cut outs (or arms of the star-shaped cut out) 11, 12, 13, and 14 alternating with the bottom cut outs 7, 8, 9, and 10 results here in a serpentine-shaped impact core 3 which is deformable in different directions.
Although the arms 11-14 and the edge cuts outs 7-10 are preferably alternating, it may be apparent to any person skilled in the art that, instead of one intermediate edge cut out 8, a multiple number of edge cut outs may be provided between two subsequent arms 12 and 13 of the top cut out.
As best can be seen in FIG. 2 d, each of the arms 11-14 of the top cut out can extend from the top of the impact core 3 downwardly towards a respective point 12 b and 13 b located above said edge. In other words, each of the arms 11-14 of the top cut out can start at said top, can extends downwardly towards the edge of the impact core 3, and can come to an end before reaching said edge.
Further, each of the elongated cut outs can extend from the edge upwardly towards a respective point 7 b, 8 b, and 9 b located below the top of the impact core 3. In other words, each of the elongated edge cut outs 7-10 can start at the edge, can extend upwardly towards the top and can come to an end before connecting with the arms 11-14.
In the shown embodiment, each arm 11-14 extends downwardly to such extent that a lower part 13 a of the respective arm 13 is at least partly located between two neighboring elongated edge cut outs 8 and 9.
In the shown embodiment, the impact core 3 is further substantially serpentine-shaped, following a substantially serpentine-shaped path extending in a circumferential direction of said impact core. The path, schematically shown in FIG. 2 d with dotted line 15, is running above upper ends 7′, 8′, and 9′ of the elongated edge cut outs and is running below lower ends 12′ and 13′ of the arms. Therefore, the path 15 is circumventing said lower ends of the arms and said upper ends of the edge cut outs.
The serpentine-shaped path 15 may be substantially sinus-shaped. Alternatively or additionally, the path 15 may be formed as a concatenation of semi-circular path sections and/or substantially apex-shaped path sections.
Preferably, the path forms a loop. This is, said path may be endless.
As best can be seen in FIG. 2 e, the impact core 3 can further comprise air channels formed as air guiding grooves 110, 120, 130, and 140. In the shown embodiment, the air guiding grooves 110-140 are substantially laying in line with the arms 11-14 of the top cut out. Besides, the edge cuts outs 7-10 may serve as further air channels.
Preferably, the impact core 3 is integrally formed, as a single piece. Further, the impact core 3 may include a single material or a single material composition.
In a preferred embodiment, the impact core 3 comprises expanded polypropylene material (EPP). This material has advantageous properties, such as the material being multi-impact and flexible. The combination of the expanded polypropylene material with the arrangement of the cut outs 7-14 results in a deformable impact core 3 which is highly durable.
In an embodiment, the density of the EPP material used for the impact core 3 lays between 20 and 100 kg/m3, and preferably is about 60 kg/m3. These densities showed good results during impact tests.
Alternatively, the impact core may comprise expanded Polyurethane (PU) or another flexible material or another flexible material composition.
The impact core 3 may be made using moulding technique. The moulding technique preferably uses a single mold which considerably reduces the manufacturing time and makes the overall process simple.
Instead of using Ethylene vinyl acetate (EVA) rubber, the comfort core 5 may comprise relative low density EPP or EPS. A typical density for an EVA rubber comfort core could be about 30 kg/m3.
Alternatively, the comfort core 5 could comprise textile, PU, rubber or Neoprene or a combination thereof. With Neoprene for example, several sheets can be sewed together to form the comfort core.
It is emphasized that the present invention can be varied in many ways, of which the alternative embodiments as presented are just a few examples. A person skilled in the art will readily appreciate that various features disclosed in the description may be modified and that various embodiments disclosed and/or claimed may be combined without departing from the scope of the invention. These different embodiments are, hence, non-limiting examples. The scope of the present invention, however, is only limited by the subsequently following claims.

Claims

1. An apparatus comprising:

an impact core for insertion inside an outer shell of a helmet, wherein the impact core comprises a shock proof material and is substantially dome-shaped having cut outs to increase the flexibility of the impact core, wherein the impact core comprises a substantially star-shaped cut out at a top of the impact core and a plurality of elongated edge cut outs near an edge of the impact core, and wherein each of a plurality of arms of the star-shaped cut out extends downward between two neighboring edge cut outs.

2. The impact core according to claim 1, wherein the star-shaped cut out is a cross-shaped cut out.

3. The impact core according to claim 1, wherein the elongated cut outs near the edge extend from the edge in a substantially upward direction.

4. The impact core according to claim 1, wherein each of the arms extends from the top of the impact core downwardly towards a respective point located above the edge, and wherein each of the elongated cut outs extends from the edge upwardly towards a respective point located below the top of the impact core.

5. The impact core according to claim 1, wherein each arm extends downwardly to such extent that a lower part of the respective arm is at least partly located between two neighboring elongated edge cut outs.

6. The impact core according to claim 1, wherein the impact core is substantially serpentine-shaped, following a substantially serpentine-shaped path extending in a circumferential direction of the impact core, the path running above upper ends of the elongated edge cut outs and running below lower ends of the arms.

7. The impact core according to claim 1, wherein the impact core comprises expanded polypropylene.

8. The impact core according to claim 1, wherein the impact core comprises expanded polyurethane.

9. The impact core according to claim 1, wherein the impact core is molded.

10. A helmet comprising:

an impact core for insertion inside an outer shell of the helmet, wherein the impact core comprises a shock proof material and is substantially dome-shaped having cut outs to increase the flexibility of the impact core, wherein the impact core comprises a substantially star-shaped cut out at a top of the impact core and a plurality of elongated edge cut outs near an edge of the impact core, and wherein each of a plurality of arms of the star-shaped cut out extends downward between two neighboring edge cut outs,

the helmet further comprising an outer shell, the impact core being arranged in the outer shell.

11. The helmet according to claim 10, wherein the outer shell comprises acrylonitrile butadiene styrene (ABS).

12. The helmet according to claim 10, wherein the outer shell has a thickness of between 0.5-3.5 mm, more preferably between 1.8-2.2 mm.

13. The helmet according to claim 10, wherein the helmet further comprises a comfort core comprising a substantially helmet shaped layer arranged at least partly inside the impact core.

14. The helmet according to claim 13, wherein the comfort core comprises EVA rubber.

15. The helmet according to claim 13, wherein the comfort core comprises an upper portion being substantially dome-shaped and a lower portion for surrounding a lower part of the skull of a user.

16. The helmet according to claim 15, wherein the upper portion of the comfort core is less thick than the lower part so as to accommodate the impact core.