bicycle helmet

Abstract

Bicycle helmet (10), comprising a shock-absorbing helmet body (11) and an outer shell (13) for the helmet body (11), wherein the outer shell (13) is made of acrylonitrile butadiene styrene (ABS) and wherein a plurality of ventilation openings (15) extend through the outer shell (13) and through the helmet body (11), characterized in that the proportion of the free area defined by the ventilation openings (15) relative to the total surface of the outer shell (13) is at least 12%, wherein the outer shell (13) is designed as an inherently rigid hard shell, and wherein the helmet body (11) and the outer shell (13) are designed as separate elements glued together.

Description

The present invention relates to a bicycle helmet having a shock-absorbing helmet body and an outer shell for the helmet body, wherein the outer shell is made of acrylonitrile butadiene styrene (ABS) and wherein a plurality of ventilation openings extend through the outer shell and through the helmet body.Bicycle helmets with a hard ABS outer shell are available as so-called Skater or BMX helmets. Due to the high impact strength and the low impact sensitivity of ABS, such skate or BMX helmets are particularly robust and durable. The wearing comfort, on the other hand, is comparatively low, in particular because of the relatively high weight and the typically only low ventilation effect. Conventional skate or BMX helmets with an ABS outer shell typically have only very small ventilation openings, which are slit-shaped, for example, and extend in two rows next to one another. Therefore, skate or BMX helmets are still used only singly for bicycling on longer distances.Especially for city running, racing running or mountain biking, bicycle helmets are preferably used which, instead of a hard ABS outer shell, have a thin coating of polyvinyl chloride (PVC), polyethylene terephthalate (PET) or a polycarbonate (PC), wherein a stiffening structure, for example in the form of a lattice structure, is sometimes integrated into the helmet body. Such bicycle helmets have a relatively high wear comfort due to the light weight and good ventilation. In addition, the PVC, PET or PC coating can be used as a carrier for visually appealing decors. However, such bicycle helmets are relatively shock-sensitive on their outer side and often even at weak impacts, such as occur during transport, carry damage to them. Bicycle helmets with PVC, PET or PC coatings are therefore less suitable for rough use.There is thus a need to provide a bicycle helmet with extended possibilities of use.US 2012 / 0 216 338 A1 discloses a bicycle helmet having an impact-absorbing helmet body and an outer shell made of acrylonitrile butadiene styrene, wherein a plurality of ventilation openings running in the longitudinal direction of the bicycle helmet extend through the outer shell and through the helmet body. EP 0 090 720 A1 discloses a bicycle helmet consisting essentially of a thermoformed helmet dome. US 2013 / 0 254 978 A1 discloses a bicycle helmet having an impact-absorbing helmet body and an outer shell made of acrylonitrile butadiene styrene, wherein ventilation openings extend through the outer shell and through the helmet body and additional evaporation openings are provided in the outer shell. EP 2 837 300 A1 (post-published) discloses a bicycle helmet having an inner reinforcing structure in the helmet body.The object is achieved according to a first aspect of the invention by a bicycle helmet having the features of claim 1.According to the first aspect of the invention, the proportion of the free surface defined by the ventilation openings is at least 12% with respect to the total surface of the outer shell. In contrast to the common principles of bicycle helmet construction in the case of skater or BMX helmets with an ABS outer shell, therefore, in the case of a helmet with an impact-resistant outer shell, relatively many and / or relatively large ventilation openings are provided. Due to the increased ventilation effect and the reduced weight, such a helmet is suitable not only as a Skater or BMX helmet for particular loads, but also for normal use, e.g. for city-wheel driving. Compared to a conventional racing bicycle helmet, however, a bicycle helmet according to the invention is distinguished by an increased robustness and durability.A ventilation opening is generally understood to mean an opening which extends continuously from the outer side of the outer shell as far as the inner side of the helmet body. In connection with the invention, the calculation of the named portion of the clearance surface relates to the outer side of the outer shell, in particular up to the respective separating plane between the outer shell and the helmet body. If the outer shell is thus recessed in the vicinity of the respective ventilation opening and / or arched in the direction of the ventilation opening, the recessed or arched surface sections should also enter into the calculation.Generally, a bicycle helmet has a concavely curved inner side and a convexly curved outer side, so that accordingly the terms "outer" and "inner" in connection with the invention refer to the correspondingly curved surfaces. Location and direction information used in connection with the invention generally relates to the intended arrangement of the bicycle helmet on or on the head of a user. For example, the term "front side" denotes the side of the bicycle helmet that is situated in the forehead area of the user and thus points in the viewing direction of the user, whereas the term "rear side" refers to the side of the bicycle helmet that is situated in the occipital and neck area of the user and thus points counter to the viewing direction of the user. The "longitudinal direction" is to be understood as the direction which extends between the front side and the rear side of the bicycle helmet.Preferably, the proportion of the free surface defined by the ventilation openings is at least 14%, particularly preferably at least 16%, based on the total surface of the outer shell. In other words, it is preferred that the proportion of the free surface is significantly increased compared to the proportion of the free surface of conventional skate or BMX helmets. In the case of conventional Skater or BMX helmets, the proportion of the free surface area, based on the total surface area of the outer shell, is typically only between 4% and 8%. Accordingly, there is a considerable increase in the aeration effect.The object stated above is achieved according to a second aspect of the invention by a bicycle helmet having the features of claim 3.According to the second aspect of the invention, the outer shell forms at least two longitudinal connecting webs which extend in sections or continuously along a longitudinal direction of the bicycle helmet, wherein a respective longitudinal row of a plurality of ventilation openings is provided on both sides of the arrangement of longitudinal connecting webs and between the longitudinal connecting webs, wherein the outer shell furthermore forms at least two transverse connecting webs which cross the longitudinal connecting webs, wherein a respective transverse row of a plurality of ventilation openings is provided on both sides of the arrangement of transverse connecting webs and between the transverse connecting webs, and wherein the ventilation openings of the longitudinal rows and the ventilation openings of the transverse rows are substantially quadrangular.The arrangement of intersecting longitudinal connecting webs and transverse connecting webs forms, to a certain extent, a lattice structure of the outer shell. In this way, despite the high free surface proportion, a high stability of the bicycle helmet is obtained, in particular a high tensile strength in the longitudinal and transverse directions. At least three longitudinal rows of in each case a plurality of ventilation openings and at least three transverse rows of in each case a plurality of ventilation openings are provided, wherein the ventilation openings of the longitudinal rows correspond at least partially to the ventilation openings of the transverse rows. As a result, the clearance area provided by the ventilation openings is particularly large. The longitudinal connecting webs, like the transverse connecting webs, can be straight or curved with respect to the convexly curved outer side of the bicycle helmet-i.e. viewed in projection.The fact that the ventilation openings of the longitudinal rows and of the transverse rows are substantially quadrangular means that they have a quadrangular basic shape, wherein the corners can, however, be rounded or beveled. For example, the ventilation openings can have a diamond-shaped or trapezoidal basic shape. The substantially square shape of the ventilation openings achieves a maximizing of the free surface of the outer shell, in particular in the region between the longitudinal connecting webs and the transverse connecting webs, without the stability of the bicycle helmet (tensile strength in the longitudinal and transverse directions) being impaired too much and without the individual ventilation openings being too large (risk of objects entering).In both aspects of the invention, the outer shell is designed as a rigid hard shell, wherein the helmet body and the outer shell are designed as separate elements which are bonded to one another.The first aspect of the invention of a high clearance area proportion according to claim 1 and the second aspect of the invention of forming longitudinal connecting webs, transverse connecting webs, longitudinal rows of ventilation openings and transverse rows of ventilation openings according to claim 3 represent two alternative aspects of the common superordinate concept of providing a bicycle helmet with both a hard and stable outer shell and with a large-area arrangement of ventilation openings. The two aspects of the invention can be combined in an advantageous manner.It is advantageous if a section of a respective longitudinal connecting web situated between a pair of ventilation openings is arranged in extension of another section of the respective longitudinal connecting web situated between an adjacent pair of ventilation openings. It is likewise advantageous if a section of a respective cross-connection web situated between a pair of ventilation openings is arranged in extension of another section of the respective cross-connection web situated between an adjacent pair of ventilation openings. In other words, the respective longitudinal connecting web or transverse connecting web of the outer shell preferably extends continuously in such a way that a section of the longitudinal connecting web or transverse connecting web is arranged in alignment with an adjacent section of the longitudinal connecting web or transverse connecting web (and is not arranged laterally offset thereto, for example). However, this does not exclude that the respective longitudinal connecting web or transverse connecting web performs a change of direction along the outer side of the bicycle helmet (e.g. as a curved path).The transverse connecting webs can extend, in particular, at least in sections along a transverse direction of the bicycle helmet, which runs at right angles to the longitudinal direction. Furthermore, it is preferred that the longitudinal connecting webs run next to one another and do not cross one another. The cross-connecting webs also preferably run next to one another and do not cross one another.A special embodiment of the invention provides that the outer shell forms two further longitudinal connecting webs which extend on both sides of the mentioned arrangement of longitudinal rows of ventilation openings, wherein the transverse connecting webs also cross the two further longitudinal connecting webs. In this embodiment, an even widened grating structure is present.The at least two longitudinal connecting webs can extend as far as a front-side edge section of the outer shell and / or as far as a rear-side edge section of the outer shell. This achieves a particularly high tensile strength of the outer shell in the longitudinal direction of the bicycle helmet.Alternatively or additionally, it can be provided that the at least two transverse connecting webs extend continuously between a left-side edge section and a right-side edge section of the outer shell. This achieves a particularly high tensile strength of the outer shell in the transverse direction of the bicycle helmet.The longitudinal connecting webs or the transverse connecting webs thus represent essential structural features of the bicycle helmet in these embodiments.The longitudinal connecting webs and the transverse connecting webs can have a width of at least 1.5 cm and at most 4 cm in the region between two ventilation openings which are separated from one another by the respective longitudinal connecting web or transverse connecting web and are therefore situated opposite one another with respect to the respective longitudinal connecting web or transverse connecting web. The minimum value mentioned here ensures the required stability of the bicycle helmet. In contrast, maintaining the stated maximum value means a relatively large proportion of the free surface defined by the ventilation openings relative to the total surface of the outer shell.With regard to the two aspects of the invention mentioned, it is preferred that the minimum width of a respective ventilation opening is at least 2 cm. The minimum width of a ventilation opening is to be understood as meaning that minimum value of the clear width of the respective ventilation opening which is related to all possible viewing directions along the surface of the bicycle helmet. It is therefore preferred to provide relatively large ventilation openings which are not particularly narrow in one direction (e.g. as ventilation slits). Large vent openings not only provide increased wearing comfort, but also provide the bicycle helmet with an visually appealing appearance. In particular, large ventilation openings can ensure that the bicycle helmet, despite the ABS shell, does not look like a typical skate or BMX helmet, but rather like a racing bicycle helmet.According to a further embodiment of the invention, at least 16 and preferably at least 18 ventilation openings are provided. The provision of such many ventilation openings contributes to a particularly good ventilation effect and gives the bicycle helmet an appealing appearance.The ventilation openings can be arranged substantially uniformly distributed over the surface of the bicycle helmet, which is favorable with regard to stability and the ventilation effect. When considering a respective region of the surface of the bicycle helmet which is larger than a single ventilation opening but smaller than the entire surface of the bicycle helmet, there is thus always obtained within the region approximately the same proportion of the clearance area, which is defined by the ventilation opening or the plurality of ventilation openings located within the region, with respect to the entire surface of the region under consideration. This applies regardless of the location of the surface of the bicycle helmet at which the considered region is selected. The term "substantially uniformly distributed over the surface of the bicycle helmet" is to be understood in this sense.It is preferred that at least one respective ventilation opening is arranged in a front side region, a rear side region, a left side region, a right side region and in a top side region of the bicycle helmet. This means that it is preferred that the bicycle helmet is provided with ventilation openings all around and not, as is usual in the case of skate or BMX helmets, only at individual insulated regions.It is further preferred that the outer shell is made entirely of acrylonitrile butadiene styrene (ABS). This ensures high impact resistance and low sensitivity to impact. In addition, ABS is well suited for applying high-quality decorative layers.One embodiment of the invention provides that the outer shell has a thickness of at least 2 mm. Such an outer shell is substantially more robust and durable than the PVC, PET or polycarbonate coatings customary, for example, in racing wheel helmets. Such an inherently rigid and thick outer shell made of ABS can be produced particularly advantageously by an injection molding process.The helmet body can be made of an expanded polystyrene rigid foam (EPS). Such helmet bodies can absorb impacts particularly well.The helmet body is preferably designed without damping recesses and / or without a stiffening structure integrated into the helmet body. Damping recesses such as, for example, weakening ribs are customary or even absolutely necessary in conventional Skater or BMX helmets in order to achieve a desired damping characteristic. However, for this purpose, special adaptations to the tool for producing the helmet body are customary. In contrast, in racing bicycle helmets, it is necessary to integrate a stiffening structure, for example in the form of a lattice structure, into the helmet body (for example by injection molding or foaming around the stiffening structure during the production of the helmet body) in order to ensure sufficient stability. It was recognized within the scope of the invention that, when providing an impact-resistant outer shell with a high surface area fraction and / or with longitudinal and transverse webs, it is possible to dispense with reinforcing elements integrated into the helmet body as well as damping recesses in the helmet body. The manufacturing cost of a bicycle helmet can thus be reduced.A further embodiment of the invention provides that the inner side of the outer shell is concave and has an extension angle along a longitudinal direction of the bicycle helmet that is greater than 180°. Such a configuration is also referred to as "negative curvature". Viewed in a central longitudinal section plane, the orthogonal formed on the course of the inner side of the outer shell in a front side region of the bicycle helmet intersects the orthogonal formed on the course of the inner side of the outer shell in a rear side region of the bicycle helmet at an overrubous angle, that is to say at an angle of more than 180°. This achieves a particularly wide enclosure of the user's head (viewed in the longitudinal direction of the bicycle helmet).During production, the helmet body can be inserted into such an outer shell with negative curvature and subsequently glued to it.As explained above, the helmet body and the outer shell are configured as separate elements that are glued together. This construction is advantageous in particular when the outer shell has a negative curvature.According to a further embodiment of the invention, a screen can be attached to the outer shell and / or to the helmet body.The invention also relates to a method for producing a bicycle helmet configured as described above.It is provided that-unlike a conventional deep-drawing process-the outer shell is produced by injection molding and the helmet body is attached to an inner side of the injected outer shell. This type of production is particularly cost-effective. In addition, during injection processes, there is a comparatively great flexibility with regard to the design, so that e.g. outer shells can be easily produced in different thicknesses and in particular in relatively large thicknesses.The helmet body is attached to the inner side of the outer shell by adhesive bonding.Further developments of the invention are also specified in the dependent claims, the description and the appended drawings.The invention will be described below by way of example with reference to the drawings. FIG. 1 shows a bicycle helmet according to an embodiment of the invention in a perspective view obliquely from the front and above. FIG. 2 shows the bicycle helmet according to FIG. 1 obliquely from behind and above. FIG. 3 shows the bicycle helmet according to FIG. 1 from the front. FIG. 4 shows the bicycle helmet according to FIG. 1 from behind. FIG. 5 shows the bicycle helmet according to FIG. 1 from above. FIG. 6 shows the bicycle helmet according to FIG. 1 from below. FIG. 7 shows the bicycle helmet according to FIG. 1 from the side.The bicycle helmet 10 shown in various views in FIGS. 1 to 7 has a shock-absorbing helmet body 11 made of an expanded rigid polystyrene foam (EPS) and an outer shell 13 connected to the helmet body 11. The outer shell 13 is made entirely of acrylonitrile butadiene styrene (ABS) and has a thickness of about 2 mm. Consequently, the outer shell 13 is inherently rigid. The outer shell 13 is preferably produced by injection molding, wherein the helmet body 11 is attached to the outer shell 13 after the injection molding process. The helmet body 11 is bonded to the outer shell 13. A plurality of ventilation openings 15 are arranged distributed over the surface of the outer shell 13 and extend through the outer shell 13 and through the helmet body 11. The ventilation openings 15 are arranged in a specific manner, as will be explained in more detail below.Specifically, the arrangement of the ventilation openings 15 is selected such that the outer shell 13 forms four longitudinal connecting webs 17 which extend along a longitudinal direction L of the bicycle helmet 10 starting from a front-side edge section 19 aof the outer shell 13 in the direction of a rear-side edge section 19 bof the outer shell 13. Furthermore, the ventilation openings 15 form a total of five longitudinal rows 20 (shown in dashed lines). The longitudinal rows 20 of ventilation openings 15 are arranged in such a way that a respective longitudinal row 20 of a plurality of ventilation openings 15 extends between the four longitudinal connecting webs 17 and on both sides of the arrangement of four longitudinal connecting webs 17. On both sides of the arrangement of five longitudinal rows 20 of ventilation openings 15, a respective diagonal connecting web 18 is furthermore provided, which extends starting from a left-side edge section 22 aand from a right-side edge section 22 bof the outer shell 13 obliquely to the longitudinal direction L in the direction of the rear side of the bicycle helmet 10.The outer shell 13 also forms two curved transverse connecting webs 21 which cross the longitudinal connecting webs 17. Furthermore, due to the arrangement of the ventilation openings 15, there are also three curved transverse rows 23 of ventilation openings 15 (likewise illustrated in dashed lines), wherein a respective transverse row 23 of ventilation openings 15 is again present between the two transverse connecting webs 21 and on both sides of the arrangement of two transverse connecting webs 21. The transverse connecting webs 21 extend transversely to the longitudinal direction L (i.e. in sections perpendicular or oblique to the longitudinal direction L) between the left-side edge section 22 aof the outer shell 13 and the right-side edge section 22 bof the outer shell 13.Overall, the outer shell 13 of the bicycle helmet 10 thus has a lattice-like basic structure. The ventilation openings 15 are diamond-shaped or trapezoidal in the exemplary embodiment shown and have rounded corners. On the front edge section 19 aof the outer shell 13, a screen 25 is arranged. If necessary, a sight may be provided instead of the screen 25 or in addition to the screen 25.The minimum width of each vent 15 defined by a longitudinal connecting web 17 or a transverse connecting web 21 is at least 2 cm. In the exemplary embodiment shown, this also applies to the three ventilation openings 15 additionally provided in the neck region of the bicycle helmet 10.Due to the number and size of the ventilation openings 15, the proportion of the free surface of the bicycle helmet 10 defined by the ventilation openings 15 is relatively large with respect to the total surface of the outer shell 13. In the exemplary embodiment shown, this proportion is approximately 17%. The relevant requirements with regard to the avoidance of injuries due to objects urgent through the ventilation openings are nevertheless fulfilled. Because of the substantially uniform distribution of the ventilation openings 15 over the entire surface of the outer shell 13, a good ventilation effect is ensured for all regions of the head in the bicycle helmet 10. Due to the self-rigid outer shell 13 made of hard ABS, it is not necessary to provide stiffening elements integrated into the helmet body 11. Furthermore, due to the grid-like structure of the outer shell 13, it is not necessary, as in conventional skate or BMX helmets, to provide damping recesses such as weakening ribs or the like in the helmet body 11. Due to the high impact strength of ABS, the outer shell 13 is protected from damage not only in the event of crashes, but also, for example, in the event of minor impacts during transport.Overall, the invention provides a bicycle helmet which is distinguished both from skate or BMX helmets and from racing bicycle helmets and is distinguished in particular by a combination of great robustness on the one hand and high wear comfort on the other hand.List of reference characters10 Bicycle helmet 11 Helmet body 13 Outer shell 15 Ventilation opening 17 Longitudinal connecting web 18 Diagonal connecting web 19 aFront edge portion 19 b Rückseitig edge portion 20 Longitudinal row 21 Transverse connecting web 22 a Linksseitige edge portion 22 b Rechtsseitige edge portion 23 Transverse row 25 Umbrella L Longitudinal direction

Claims

Bicycle helmet (10), having an impact-absorbing helmet body (11) and an outer shell (13) for the helmet body (11), wherein the outer shell (13) is manufactured from acrylonitrile butadiene styrene (ABS) and wherein a plurality of ventilation openings (15) extend through the outer shell (13) and through the helmet body (11), characterized in that the proportion of the free surface defined by the ventilation openings (15) is at least 12% with respect to the total surface of the outer shell (13), wherein the outer shell (13) is designed as an intrinsically rigid hard shell, and wherein the helmet body (11) and the outer shell (13) are designed as separate elements which are bonded to one another.The bicycle helmet according to claim 1, wherein the proportion of the clearance area defined by the ventilation openings (15) is at least 16% relative to the total surface area of the outer shell (13).Bicycle helmet (10), having an impact-absorbing helmet body (11) and an outer shell (13) for the helmet body (11), wherein the outer shell (13) is manufactured from acrylonitrile butadiene styrene (ABS) and wherein a plurality of ventilation openings (15) extend through the outer shell (13) and through the helmet body (11), characterized in that the outer shell (13) forms at least two longitudinal connecting webs (17) which extend at least in sections along a longitudinal direction (L) of the bicycle helmet (10), wherein a respective longitudinal row (20) of a plurality of ventilation openings (20) is provided on both sides of the arrangement of longitudinal connecting webs (17) and between the longitudinal connecting webs (17), wherein the outer shell (13) furthermore forms at least two transverse connecting webs (21) which cross the longitudinal connecting webs (17), wherein a respective transverse row (23) of a plurality of ventilation openings (15) is provided on both sides of the arrangement of transverse connecting webs (21) and between the transverse connecting webs (21), wherein the ventilation openings (15) of the longitudinal rows (20) and the ventilation openings (15) of the transverse rows (23) are substantially quadrangular, wherein the outer shell (13) is designed as a self-rigid hard shell, and wherein the helmet body (11) and the outer shell (13) are designed as separate elements which are bonded to one another.The bicycle helmet according to claim 3, wherein the outer shell (13) forms two further longitudinal connecting webs (17) which extend on both sides of the arrangement of longitudinal rows (20) of ventilation openings (15), wherein the transverse connecting webs (21) also cross the two further longitudinal connecting webs (17).The bicycle helmet according to claim 3 or 4, wherein the at least two longitudinal connecting webs (17) extend as far as a front edge section (19a) of the outer shell (13) and / or as far as a rear edge section (19b) of the outer shell (13).The bicycle helmet according to at least one of claims 3 to 5, wherein the at least two cross-connecting webs (21) extend continuously between a left-side edge portion (22a) and a right-side edge portion (22b) of the outer shell (13).The bicycle helmet according to at least one of claims 3 to 6, wherein the longitudinal connecting webs (17) and the transverse connecting webs (21) each have a width of at least 1.5 cm and at most 4 cm in the region between two ventilation openings (15) which are separated from one another by the respective longitudinal connecting web (17) or transverse connecting web (21).The bicycle helmet according to at least one of claims 3 to 7, wherein the proportion of the free surface defined by the ventilation openings (15) relative to the total surface area of the outer shell (13) is at least 12%.The bicycle helmet according to claim 8, wherein the proportion of the clearance area defined by the ventilation openings (15) is at least 16% relative to the total surface area of the outer shell (13).The bicycle helmet according to at least one of the preceding claims, wherein the minimum width of each vent hole (15) is at least 2 cm.Bicycle helmet according to at least one of the preceding claims, wherein at least 16 and preferably at least 18 ventilation openings (15) are provided.The bicycle helmet according to at least one of the preceding claims, wherein the ventilation openings (15) are arranged substantially uniformly distributed over the surface of the bicycle helmet (10).The bicycle helmet according to at least one of the preceding claims, wherein at least one respective ventilation opening (15) is arranged in a front side region, a rear side region, a left side region, a right side region and in a top side region of the bicycle helmet (10).The bicycle helmet according to at least one of the preceding claims, wherein the outer shell (13) is made entirely of acrylonitrile butadiene styrene (ABS).Bicycle helmet according to at least one of the preceding claims, wherein the helmet body (11) is made of an expanded polystyrene rigid foam (EPS).Bicycle helmet according to at least one of the preceding claims, wherein the helmet body (11) is designed without damping recesses and / or without stiffening elements integrated into the helmet body (11).The bicycle helmet according to at least one of the preceding claims, wherein the inner side of the outer shell is concave and has an extension angle along a longitudinal direction (L) of the bicycle helmet (10) that is greater than 180°.Method for manufacturing a bicycle helmet (10) configured according to any of the preceding claims, characterized in that the outer shell (13) is produced by injection molding and the helmet body (11) is attached to an inner side of the injected outer shell (13) by adhesive bonding.

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