IMPACT PROTECTION STRUCTURE

Abstract

The invention relates to an impact protection structure, in particular for a helmet, to absorb kinetic energy during an impact, in particular a fall, comprising a plurality of cells arranged next to one another, wherein each cell has a hollow interior (1), which is delimited by at least one side wall (2), wherein cells adjoining one another have at least one common side wall (2), wherein the interior (1) and the side walls (2) run from an outer side (3) of the impact protection structure to an inner side (4) of the impact protection structure opposing the outer side (3), wherein at least one side wall (2) of a cell has at least one recess (5).

Claims

1. An impact protection structure, in particular for a helmet, to absorb kinetic energy during an impact, in particular a fall, comprising a plurality of cells arranged next to one another, wherein each cell has a hollow interior (1), which is delimited by at least one side wall (2), wherein cells adjoining one another have at least one common side wall (2), wherein the interior (1) and the side walls (2) run from an outer side (3) of the impact protection structure to an inner side (4) of the impact protection structure opposing the outer side (3), characterized in that at least one side wall (2) of a cell has at least one recess (5).

2. The impact protection structure according to claim 1, characterized in that the outer side (3) and/or the inner side (4) of the impact protection structure is arranged in a flat or curved, in particular parabolic or hemispherical surface.

3. The impact protection structure according to claim 1 or 2, characterized in that the impact protection structure on the inner side (4) has an inner contact surface (4) formed by the cross-sectional surface of the side wall (2) delimiting the side wall (2) on the inner side.

4. The impact protection structure according to any one of claims 1 to 3, characterized in that the cross-section of the interior (1) of the cells tapers from the outer side (4) of the impact protection structure towards the inner side (3), wherein in particular it is provided that the side walls (2) expand from the outer side (3) towards the inner side (4), preferably at an angle of between 0.5 to 5°.

5. The impact protection structure according to any one of claims 1 to 4, characterized in that the side walls (2) from the outer side (3) to the inner side (4) have a height of 0.3 cm to 50 cm, in particular of 0.5 cm to 20 cm and/or in that the side walls (2) in the cross-section have a wall thickness of 0.5 mm to 50 mm.

6. The impact protection structure according to any one of claims 1 to 5, characterized in that in the region of the recess (5) the surface of the side wall (2) is reduced, wherein it is in particular provided that the recess (5) is arranged adjoining the outer side (3) and/or the inner side (4) of the impact protection structure, wherein the height of the side wall (2) is reduced in the region of the recess (5).

7. The impact protection structure according to any one of claims 1 to 6, characterized in that the recess (5) is formed as an arc or polygon, in particular as a rectangle and/or in that the recess (5) is arranged in a middle region of the side wall (2) spaced apart from the side walls (2) adjoining the respective side wall (2) and/or in that the recess (5) is 0.01% to 70%, in particular 15% to 60%, preferably 30% to 50% of the area of the respective side wall (2).

8. The impact protection structure according to any one of claims 1 to 7, characterized in that 5% to 100%, in particular at least 20%, preferably at least 70% of the cells have a side wall (2) with a recess (5).

9. The impact protection structure according to any one of claims 1 to 8, characterized in that the surface of the side wall (2) facing the interior (1) is formed flat or is composed of a plurality of in each case flat surface regions.

10. The impact protection structure according to any one of claims 1 to 9, characterized in that the cells of the impact protection structure form a honeycomb structure and/or in that the interior (1) has at least one cell, in particular a plurality of cells adjoining one another, a polygonal, in particular hexagonal, cross-section, wherein it is preferably provided that the interior (1) of a number of the cells on the outer side (3) and/or on the inner side (4) of the impact protection structure has a polygonal, in particular hexagonal, cross-section.

11. The impact protection structure according to any one of claims 1 to 10, characterized in that the cells each have six side walls (2), wherein the edges of the side walls (2) delimit the cross-sectional surface of the interior (1) and have an edge length, wherein side walls (2) opposing one another in relation to the interior (1) each have the same edge length and wherein it is in particular provided that four long side walls (2) are provided with a longer edge length and two short side walls (2) with a shorter edge length.

12. The impact protection structure according to any one of claims 1 to 11, characterized in that in each case one recess (5) is formed in at least two, in particular in all four long, side walls (2) of a cell opposing one another in relation to the interior (1) and/or in that no recess (5) is formed in two, in particular short, side walls (2) of a cell opposing one another in relation to the interior (1).

13. The impact protection structure according to any one of claims 3 to 12, characterized in that the inner contact surface of cells adjoining one another forms an arrow delimited by recesses (5), located in particular in the surface of the inner side and open on both sides.

14. The impact protection structure according to any one of claims 1 to 13, characterized in that the impact protection structure consists of a, in particular foamed, thermoplastic elastomer, preferably of polyurethane, copolyester, polyamide, polyolefin and/or styrene block copolymer.

15. An impact protector, in particular helmet, comprising an impact protection structure according to any one of claims 1 to 14, characterized in that fastening means are provided for fastening to a body to be protected, wherein the inner side (4) of the impact protection structure can be arranged facing the body and wherein the recess (5) is provided on the inner side (4) of the impact protection structure.

16. The impact protector, in particular according to claim 15, comprising an impact protection structure, in particular according to any one of claims 1 to 14, characterized in that an outer shell is arranged on the impact protection structure at an outer side (3) of the impact protection structure which can be arranged facing away from the body to be protected.

17. The impact protector according to claim 16, characterized in that fastening elements, in particular belts, are provided at the connection points (6) for fastening the impact protector to a body.

18. The impact protector according to any one of claims 15 to 17, characterized in that the outer shell is formed of a thermoplastic material or polycarbonate or a carbon fiber material.

Description

[0053] A particularly advantageous embodiment of the invention is represented by way of example on the basis of the following drawings without the general inventive concept being limited.

[0054] FIG. 1 shows an exemplary impact protection structure for a helmet in a frontal view.

[0055] FIG. 2 shows the helmet from FIG. 1 in a top view.

[0056] FIG. 3 shows the helmet from FIG. 1 in a rear view.

[0057] FIG. 4 shows the helmet from FIG. 1 in a side view.

[0058] FIG. 5 shows the helmet from FIG. 1 in an oblique view.

[0059] FIG. 6 shows the helmet from FIG. 1 in a view from below.

[0060] FIG. 7 shows the helmet from FIG. 1 in an oblique view from laterally below.

[0061] FIG. 8 shows the helmet from FIG. 1 in an oblique view from the front, below.

[0062] FIG. 9 shows the helmet from FIG. 1 in a view from the rear, below.

[0063] FIGS. 10 to 10h different possible designs of the individual cells according to the invention.

[0064] FIGS. 11a to 11f different designs of the side walls according to the invention.

[0065] FIGS. 12a to 12b embodiments of arrangements of cells with and without recesses.

[0066] FIGS. 13 to 13c designs of cells with support surfaces or feet.

[0067] FIGS. 14a to 14d alternative designs of the side walls.

[0068] FIG. 1 shows an impact protection structure according to the invention for a helmet, in particular a bicycle helmet, in a frontal view to the front end of the helmet. The impact protection structure consists of a plurality of cells arranged next to one another. The cells have a hollow interior 1, which is delimited by side walls 2, with cells adjoining one another having a common side wall 2. The cells are open upwards and downwards.

[0069] The height of the side walls 2 determines the height of the impact protection structure or the distance between an outer side 3 of the impact protection structure and an inner side 4 of the impact protection structure. The height of the side walls can be 0.3 to 6 cm. A height of up to 50 cm is also possible for impact protection structures, which are not supported on the body.

[0070] The side walls 2 can have a wall thickness of 0.5 mm to 50 mm and have a wall thickness of 1 mm in the represented embodiment on the outer side 3. Furthermore, the side walls 2 can expand from the outer side 3 towards the inner side 4 at an angle of 0.5° to 5° and expand in the represented embodiment towards the inner side 4 by 1°. The interior 1 therefore tapers from the outer side 3 towards the inner side 4. The outer side 3 and the inner side 4 are each arranged in one surface. The surface can be flat or curved, in particular parabolic or hemispherical in each case. In the embodiment represented, this surface is in each case curved.

[0071] The outer side 3 is formed in a partial region from the front end to the neck end and in a further partial region above the ear recesses of a polygonal, in the present embodiment, hexagonal structure. The hexagons each have four long sides of equal length and two short sides opposing one another. The short sides are arranged in the represented embodiment parallel to the front and neck end. Through this design, compression is particularly easily possible in the impact protection structure from the front to neck region, i.e. in the direction of a ‘yes’ nodding movement.

[0072] Fastening points are provided on the border region to fasten the impact protection structure to a body. The fastening points form the corner points of a regular trapezoid. The fastening points can be used as connection points 6 to connect with an outer shell.

[0073] What is not represented is the possibility concerning an independent partial aspect of the invention of providing an outer shell on an impact protection structure to improve the protective effect, with the outer shell being connected to the impact protection structure at connection points 6. The outer shell can for example consist of polycarbonate with a thickness of 0.5 to 3.5, in particular 1.5 mm.

[0074] The represented embodiment of the impact protection structure according to the invention is manufactured from a thermoplastic elastomer in an injection-molding process. The thermoplastic elastomer can be a polyurethane, copolyester, polyamide, polyolefin or styrene block copolymer or a polyblend.

[0075] FIG. 2 and FIG. 3 show that the hexagonal structure of the outer side 3 is formed over the entire longitudinal side of the head, i.e. from the front end to the neck end. In this partial region, the side walls 2 in the represented embodiment have a height of 31 mm. The side walls 2 therefore have a wall thickness of 2.2 mm on the inner side 4.

[0076] FIG. 4 and FIG. 5 show that a partial region with the hexagonal structure is also formed laterally, above the ear recesses. In this partial region, the side walls 2 in the represented embodiment have a height of 22 mm. The side walls 2 therefore have a thickness of 1.1 mm on the inner side 4.

[0077] The height of the side walls 2 continually decreases between the middle and the lateral partial regions with hexagonal structure such that the outer side 3 and the inner side 4 are arranged on one surface.

[0078] FIG. 4 shows that in the represented embodiment cells, which are arranged on the border of the impact protection structure or between the regular partial regions, and also have a polygonal structure.

[0079] FIG. 6 shows the impact protection structure viewed from the inside of the helmet. In the middle region of the helmet, which is arranged on the crown, the inner side 4 also has a hexagonal structure. The cells in this region also have four long side walls 2 of equal length and two short side walls 2 opposing one another in relation to the interior 1. The long side walls 2 each have in the inner support surface 4 a recess 5. The height of the side wall 2 reduces in the region of the recess 5. The recess 5 is in each case arranged in the middle region of the side walls 2, spaced apart from the adjacent side walls 2. The recesses 5 are formed in an arc-shape in the partial regions with hexagonal structure. In the represented embodiment, the recesses 5 have a size of 10*12 mm or 8*12 mm in the partial region as a function of the height of the side wall 2. The inner support surface formed on the inner side 4 by the cross-section of the side walls 2 is formed in the partial region in the form of an arrow with two open ends or in the form of an I beam or T beam 7.

[0080] FIG. 7 shows that this design is also reflected in the side regions such that a majority of the inner side 4 has this I beam shape or T beam shape 7.

[0081] FIG. 8 shows that the design of the impact protection structure changes from the crown region to the neck region. In this region, the interior 1 of the cells tapers due to the curvature of the impact protection structure. The inner side 4 is in this region formed in a rhombus shape without a recess. Another design of the inner side 4 is also found in the border regions and between the partial regions with hexagonal structure.

[0082] FIG. 9 shows that on the inner side 4 is formed an inner support surface formed by the cross-sectional surface of the side walls 2 in the form of an arrow 7 with two open ends or in the form of an I beam or T beam. The inner support surfaces are spaced apart from one another by recesses 5. The recess in the partial region with hexagonal structure occupies approx. 45% of the area of the side wall 2. As a result, good ventilation, a notable weight reduction and selective deformation or possibly a selective collapsing of the impact protection structure can be achieved.

[0083] The represented embodiment of the impact protection structure therefore offers a good protective effect with high wearing comfort.

[0084] The invention provides in a preferred embodiment a polygonal and/or round and/or oval, prism-shaped thermoplastic structure of the cells or of the impact protection structure, hereinafter referred to only as “polygonal or cylindrical prism structure”. From substantially along a normal vector to the plane of the respective polygon or cylinder or extruded polygon (FIG. 10a), whose walls or side walls 2 with deviations of up to +/−60° (angle α, FIG. 10b) are oriented substantially perpendicular to the top surface of the body to be protected, i.e. perpendicular to the curved inner side 4. The wall thickness of the extruded polygonal structure is 0.1% to 40% of the average diameter of the respective polygon, the height of the wall or side wall 2 itself can be 10% to 1000% of its wall thickness. The profile of the side wall 2 or of the wall of the cells can in the side elevation correspond to a rectangle (FIG. 11a), to a positive trapezoid (FIG. 11b), to a negative trapezoid (FIG. 11c), to a positive double trapezoid (FIG. 11d), to a negative double trapezoid (FIG. 11e), to an ellipsoid (FIG. 11f) or to another geometric or irregular surface. The edges of the side wall 2 in the side elevation can be configured either straight or arced or partially straight and partially arced on the inner side 4 and/or the outer side 3. The walls of the respective polygons or cylinders or of the cells can in the top elevation be either straight or arced or partially straight and partially arced and have different geometric shapes (FIGS. 14a to 14d). The walls or the side walls 2 of each extruded polygon or of the cell can optionally be parallel to one another such that each wall or side wall 2 can also follow a suitable extrusion vector (FIG. 10c). An extrusion vector is in this case understood as the vector under which the polygon base surface, i.e. the polygon along the height or the cell or the side wall 2 extends to the cover surface of the cell. In this case, during extrusion, edges can also collapse such that the polygon or the cell has on one side, i.e. the inner side 4 or the outer side 3, more or fewer sides than the polygon or the cell on the inner side 4 or the outer side 3 or on the other side (FIG. 10d, 10e). Similarly, the polygon of one side can be larger or smaller than the polygon of the other side (FIG. 100, which means that the polygon or cylinder or the cell undergoes a negative or positive tapering of the structure from outside inwards or from the outer side 3 towards the inner side 4 or vice versa. The polygon of one side can also have a different geometry to the polygon of the other side (FIG. 10g). Extrusion curves can also be used instead of the extrusion vectors (FIG. 10h). In particular, a plurality of extrusion vectors and/or extrusion curves can also be used for each side wall 2 in order to form the cells or the polygon structure.

[0085] The invention also provides selective weakening points of one or a plurality of walls of all or individual walls or side walls 2 of the polygonal or cylindrical prism structure (FIGS. 12a and 12b). In this case, [0086] either recesses 5 or slots in the “lower region”, i.e. on the side of the polygonal or cylindrical prism structure which is arranged closer to the object to be protected or to the inner side 4; [0087] and/or recesses 5 or slots in the “upper region”, i.e. on the side of the polygonal or cylindrical prism structure which is arranged further from the object to be protected or from the outer side 3; [0088] and/or recesses 5 arranged at other points of the polygonal or cylindrical prism structure; [0089] and/or the wall thickness of the polygonal or cylindrical prism structure selectively thinned at one or a plurality of the mentioned points; [0090] and the recesses 5 and the thinned portions can be arranged either in the region of the surfaces of a wall or a plurality of walls of the polygonal or cylindrical side walls 2; [0091] and/or can be arranged in the region of the corner edges of two or a plurality of walls or side walls 2 of the polygonal or cylindrical walls; [0092] and the area of the recesses 5 and/or the thinned portions can be 0.1% to 70% of the sum of all wall surfaces of each individual polygonal and/or cylindrical wall connection and between 0.1% and 70% of all polygonal and/or cylindrical wall connections; [0093] and the layout of a recess 5 can take any desired shape, including in particular rectangles, trapezoids, triangles, other polyhedrons, round and/or oval, convex and/or concave shapes; [0094] and the recesses 5 can also serve to supply fresh cool air and/or to discharge already heated cool air; [0095] and for the loading limits, from which a folding-in of the structure is initiated through the recess 5 and/or thinned portion of the wall of the cell or the side wall 2 and/or the edge (target bend point), in addition to the climatic conditions and the material of the structure, in particular height, width, outline and area of the recess 5 or thinned portion of the wall, in this respect are relevant, as thicker walls, more rigid materials, lower temperatures and smaller or fewer sections or recesses 5 or thinned portions generally speaking have a stiffening effect on the structure and conversely, thinner walls, softer materials, higher temperatures and larger or more sections or thinned portions generally speaking have a softening effect on the structure such that with variations of these variables for the respective application, for the respective standards and for the respective other framework parameters (e.g. ski helmet, low temperatures, bicycle helmet, high temperature) the structures can each be optimized in regard to the desired target parameters, including in particular also the target parameters “low overall weight of the structure”; [0096] with all mentioned factors substantially contributing to keeping the flanks of the curve of the in particular negative acceleration during the conversion of kinetic energy into heat energy as rigid as possible and the plateau wide and low in order to thereby reduce the loading peaks and to avoid in this manner injuries and destruction of the respectively protected body.

[0097] The invention further comprises the possibility of attaching “feet” 9 to the (inner) side or inner side 4 of the impact protection structure or the cells facing the protected body, and these feet 9 can be any desired size and thickness and any desired layout. These feet 9 can in particular be oriented in the form of an inverted T beam, with the cross beam downwards, towards the body to be protected and the wall being attached as a longitudinal beam (FIG. 13a) along the entire inner edge of the wall, along only one part of the walls or in particular only in a certain area in relation to the intersection points of the walls of the polygonal structure. In this case, the two transverse wings of the support surface can be oriented to one another not only at an angle of 180° (FIG. 13a) but rather they also have a larger (FIG. 13b) or smaller angle (FIG. 13c). In particular in the case of a smaller angle (“inverted V position), there is a better adaptation to the different topographies of different head top surfaces. In this case, the cross-section resembles less an inverted T and more an inverted Y (FIG. 13c).

[0098] The feet 9 or support surfaces, which are connected to the sides of the polygonal walls facing the body to be protected, are characterized in that [0099] the support surfaces or feet are oriented substantially parallel to the top surface of the body to be protected and in this manner enlarge the support surface or the feet of the structure on the body to be protected, [0100] and the support surfaces or feet 9 can have any desired thickness, contour and position; [0101] and in particular the two top surfaces of the support surfaces or feet 9 do not have to be parallel; [0102] and the support surfaces or feet 9 can be oriented in relation to the intersecting axis with the wall to one another either parallel (angle 180°) or in a positive or in a negative angle or can have a plurality of angle positions over the course along the edge; [0103] and the support surfaces or feet in this case in particular can be attached along the entire edges of the walls or side walls 2 or only one part of the walls or side walls 2 and/or can be attached only to the intersecting points of the polygonal walls.

[0104] An exemplary form of the invention provides a hexagonal structure to protect the head (=helmet), with the average diameter (distance opposing corners) of the hexagons being 35 mm, the wall thickness in the region close to the head, on the inner side 4 being 1.2 mm and in the region remote from the head, i.e. the outer side 4, being 1.0 mm, and the wall height being 32 mm.

[0105] Through the manner of construction of the impact protection structure according to the invention, the following positive effects of the invention result, with reference to the previous prior art: [0106] 1. Through the selective weakening of the structure by recesses/thinned portions, a “target fold point” develops at which the polygonal structure begins to fold in relatively early during the “brake process”. This folding-in process continues during the course of further impact into the adjoining wall structures. [0107] 2. Through the force-fitting connections of the walls with one another, there is a comparably resistant reaction of the structure, with the reaction taking place continuously at a comparatively flat level such that extremely high loading peaks are prevented. [0108] 3. Due to the folding in that has begun, the parts of the polygonal or cylindrical prism structure (walls, corners, bridges, edges, etc.), which have not even been weakened themselves, but which are connected in a force-fitting manner to a weakened or initially folded-in part, are gradually folded in. Due to the flexing work connected thereto, there is a conversion of the kinetic energy into heat energy. A permanent plastic deformation of the structure largely does not take place in the normal range. [0109] 4. In the case of the specific structure, the volume of the air space in the region between inner level (level of the “lower” end of the walls) and the outer level (level of the “upper” end of the walls) prevails such that there is enough space for the folding in of the components of the structure. The structure can therefore fold in comparatively easily to the extent of the air space. Furthermore, the polygonal network of walls transfers fold-in torques to adjoining walls, which are not directly affected by the impact, such that the region, in which the kinetic energy is converted by flexing work into heat energy, is enlarged. If the air space comprises e.g. 80% of the total space, then the structure can also fold in to around 20% of its starting height (and, depending on the elastic compressibility of the material used for the structure, even beyond this). The available “brake path” is therefore in this case around 80% (or more) of the original structural height of the protection structure. As a result, a comparatively long “brake path” can be implemented, whereby in turn the loading peaks are lower. [0110] 5. The structure begins to fold out again directly following the end of the force input (=end of the phase of the negative acceleration). The folding-out process is in this case, depending on the material used for the structure and climatic conditions, slower by the factor 2 to 50 than the folding-in process that took place under the force effect such that a “rebounce effect” cannot occur on the body to be protected (and therefore no double loading) in the case of the folding-out process. At the same time, the folding-out process is only very short such that the fully unfolded protection structure is available again in the case of a possible second impact following shortly after the first impact. [0111] 6. Through the selection of materials suitable for the respective climate window, a plastic deformation of the structure or even a breakage do not result in the case of falls according to EN 1078 because the structure can elastically adapt to the environment. As a result, the structure, unlike conventional structures, is also capable of multiple impacts. [0112] 7. The polygonal structure of the walls ensures that the structure does not simply “collapse in on itself” during normal force influences, but rather, especially in the event of an oblique force effect (much more frequent in practice), it folds towards the corresponding side. As a result, a further reduction of rotational accelerations is effected, with the result that consequences of injury in the case of an impact are excluded either entirely or are at least significantly lower. [0113] 8. Through materials, which can be applied only for the first place with the structure object of the invention (not conventional polystyrene), microcracks cannot occur as a result of (generally unrecognized) minimal prior damage. Therefore, the structure is also reliable in the cases where conventional protection structures made of polystyrene entail the high risk of a premature breakage as a result of (usually unrecognized) microcracks in the event of an impact. [0114] 9. The wearing comfort is increased by the contact surface, in particular in the case of the “inverted Y” variant the adaptation of the protection structure to different topographies of different head shapes is improved and the pressure of the support surfaces of the structure on the head top surface (N/cm.sup.2 support surface) is significantly reduced by an enlargement of the support surface. This improves both the wearing comfort and reduces the risk of injury in the case of accidents.