Safety device with helmet and airbag unit

Abstract

A safety device for the head of a human is described. This safety device comprises a helmet having a helmet body and an airbag unit attached to said helmet body. This airbag unit comprises an airbag having at least one protection section, an inflator (56) being in fluid communication to said airbag, and a triggering assembly (60) for triggering said inflator (56). The triggering assembly (60) comprises at least one crash sensor (66) and a battery (62). In order to avoid an unnecessary triggering of the inflator, the airbag unit (50) further comprises a use detection arrangement (70) for distinguishing between an unworn state and a likely worn state of the helmet body, such that the use detection arrangement (70) is in a first state when it detects the unworn state and in a second state when it detects the likely worn state. The use detection arrangement comprises at least one sensor (34, 40). When the use detection arrangement (70) is in its first state, the triggering of the inflator (56) by the triggering assembly (60) is disabled, and when the use detection arrangement (70) is in its second state, the triggering assembly (60) is enabled to trigger the inflator (56) when a crash is detected by the triggering assembly (60).

Description

[0001] Safety device with helmet and airbag unit

[0002] Description

[0003] The invention relates to a safety device for the head of a human according to the preamble of claim 1 .

[0004] Especially for bicycle riders and motorcyclists, a helmet is the most important wearable safety device. Although the invention described hereinafter mainly refers to such safety devices being used in connection with riding or driving of a vehicle, the invention is of course not limited to this kind of usage. But, for the sake of simplicity, reference is mainly made to safety devices being used by bicycle riders and safety devices that are used by motorcyclists.

[0005] All those safety devices have in common that they comprise a helmet having a helmet body. In almost all cases such a helmet additionally comprises a chin strap having a buckling device. Most bicycle helmets would not be usable at all without a chin strap, in case of a motorcycle helmet, a chin strap is usually necessary in order to ensure that the helmet stays in place (meaning on the head) in case of an accident (when the helmet is needed). In other words: In order to achieve the maximum safety level, a chin strap must be provided and of course be buckled when the helmet is worn.

[0006] In addition to the helmet body and the chin strap, other elements, for example a visor, a chin-bar or a so-called BOA-system can be provided.

[0007] In order to enhance the protection provided by such a safety device comprising a helmet, it has been proposed to integrate an airbag unit to the helmet body of a helmet. Integrating an airbag unit provides additional protection in certain scenarios while the helmet offers valid protection in itself. Such an airbag unit comprises an airbag having at least one protection section, an inflator (for example a gas generator) being in fluid communication with the airbag and a triggering assembly for triggering the inflator. Such a triggering assembly always comprises at least one crash sensor (usually an acceleration sensor) and a battery. It is possible that the battery is detachably mounted, such that it can be replaced or be charged in a separate charging station. So, the feature that the triggering assembly comprises a battery is to be understood in such a way that a battery must be present at least in the operational state of the triggering assembly (and thus the operational state of the airbag unit).

[0008] Such a safety device can be used for many years (like a traditional helmet) as long as the inflator is not triggered. But, after triggering of the inflator, the safety device must usually be replaced completely, meaning that it has to be thrown away and the new one has to be purchased.

[0009] Starting from this prior art it is an object of the invention to improve a generic safety device in such a way that its average live-time is extended without reducing its protective properties.

[0010] This task is solved by a safety device having the features of claim 1 .

[0011] As has been explained above, the triggering assembly of such a safety device always comprises a crash sensor, which is most often in form of an acceleration sensor as is known from traditional airbag units being mounted in a vehicle, especially a car. In case of an airbag unit being mounted in a car, a relevant acceleration (which is usually a negative acceleration meaning a deceleration) only takes place in case of an accident, such that a triggering of the inflator also only occurs in case of an accident. But it turned out that in case of safety devices comprising a helmet and an airbag unit being attached to a helmet, the situation is different:

[0012] Here, there is a certain possibility that an acceleration leading to the triggering of the inflator takes place not during an accident, but when the helmet of the safety device is not being worn. To give a simple example for such an event: The safety device can fall down from the table or similar and the critical acceleration can be reached during this. Often, the helmet as such would still be useable after such an event, but, as has been described above, when the inflator is triggered, at least the airbag unit, usually the whole safety device (including the helmet) must be replaced. In order to avoid such events at least with a high degree of probability, a use detection arrangement for distinguishing between an unworn state and a likely worn state of the helmet body is provided. This use detection arrangement is in a first state when it detects the unworn state and in a second state when it detects the likely worn state. When the use detection arrangement is in its first state, the triggering assembly is disabled, and when the use detection arrangement is in its second state, the triggering assembly is enabled. By this measure, a triggering of the inflator can be prevented when the helmet of the safety device is not worn with a high degree of likeliness.

[0013] The use detection arrangement can additionally be used for saving the battery’s energy: Most of the time, a helmet is not being worn and in this state, the triggering assembly can automatically be set to an energy saving resting state in which, for example, the crash sensor is de-activated. So, in a preferred embodiment, the triggering assembly is in such an energy saving resting state when the use detection arrangement is in its first state and the triggering assembly is in an active state when the use detection arrangement is in its second state.

[0014] As has been described above, the helmet usually comprises a chin strap with a buckling device, such that the chins strap has an open state and a closed state. It turned out that the state of the buckling device can be very useful in order to define the state of the use detection arrangement. In a preferred embodiment, the buckling device thus comprises a buckling sensor (for example a micro switch) being a part of the use detection arrangement and the use detection means is in its first state, when the buckling sensor detects the open state.

[0015] It is possible that the buckling sensor is the only sensor of the use detection arrangement. In this case, the use detection arrangement is in its second state when the buckling sensor detects the closed state.

[0016] In another embodiment, the use detection means comprises a proximity- and / or contact sensor for detecting the presence of an object at or near an inner surface of the helmet body. In this case, the use detection arrangement is in its first state when the proximity- and / or contact sensor does not detect the presence of an object at or near an inner surface of the helmet body. It is possible that the proximity- and / or contact sensor is the only sensor of the use detection arrangement. In this case, the use detection arrangement is in its second state when the proximity- and / or contact sensor detects the presence of an object at or near an inner surface of the helmet body.

[0017] In a highly preferred embodiment, the use detection arrangement comprises both: a buckling sensor and a proximity- and / or contact sensor. In this case, the use detection arrangement is only in its second state when the buckling sensor detects the closed state and the proximity- and / or contact sensor detects the presence of an object at or near an inner surface of the helmet body. By these measures the probability that a likely worn state is detected although the helmet is not being worn, is very low.

[0018] The helmet body extends in a first direction from a rim forming its lower end to an upper end and in a second direction from a rear end portion to a front end portion. The inflator preferably has an oblong shape and extends from a first end portion to a second end portion, wherein the first end portion of the inflator comprises a connector being electrically connected to the triggering assembly and the second end portion of the inflator comprises a gas outlet.

[0019] According to another aspect of the invention, the first end portion of the inflator is located at the rear end portion of the helmet body remote from the lower end of the helmet body and the inflator extends from its first end portion along an upper surface of the helmet body towards the front end portion of the helmet body. By this measure, the inflator is in a position that is at least statistically less critical for the head, and the distance between the gas outlet and the airbag, especially its protection section, that preferably comprises a section at a forehead area of the helmet body, is short, such that the airbag is filled very quickly. Both contributes to an even enhanced level of protection. In some embodiments, the protection section extends from the forehead area to the sides of the helmet.

[0020] The helmet body usually comprises a symmetry plane (like the head to be protected) and usually it is preferred that the inflator is located in this symmetry plane. According to another aspect of the invention, at least the battery of the triggering assembly, preferably the whole triggering assembly, is located between the first end portion of the inflator and the lower end of the helmet body. This location is, among others, preferred since this is a location that is unlikely to hit an obstacle during an accident, at least not first. Additionally, this position can give easy access to the battery such that it can easily be charged in its mounted state. This position is especially suitable in case that the helmet is a motor cycle helmet, especially a full helmet or a jet-type helmet.

[0021] The helmet body usually comprises a main body made from a foamed material and a rigid shell covering the main body on the outside of the main body. This applies to rather heavy motorcycle helmets as well as to light-weight bicycle helmets. It turned out to be preferable to locate at least the protection section of the airbag, preferably the whole airbag and the inflator, outside the rigid shell, such that the structure of the helmet body remains intact when the airbag deploys. Further, the assembly is simplified and the airbag unit can be accessed without de-assembly of the helmet body. In order to protect the parts of the airbag unit being located outside the shell, it is preferred to provide a cover element which covers at least those parts of the airbag unit. It is especially preferred that the cover element is single-pieced.

[0022] It can further be preferred that at least the battery of the triggering assembly, preferably the whole triggering assembly, is located between the main body and the rigid shell, such that it is protected from environmental influences. In this connection it is especially preferred that the triggering assembly is located between the first end portion of the inflator and the lower end of the helmet body, as described above, such that it can easily be mounted and accessed.

[0023] The just described preferred locations of the inflator and the triggering assembly can also be used independently from the presence of a use detection arrangement.

[0024] The invention will now be described by means of preferred embodiments in view of the figures. The figures show: Figure 1 a schematic sectional view through a precursor of a safety device according to the invention, wherein the helmet of this safety device is a full helmet,

[0025] Figure 2 a plane view onto the precursor of Figure 1 ,

[0026] Figure 3 the complete safety device (meaning the precursor of Figure 1 and a cover element being attached to it) in a representation according to Figure 1 ,

[0027] Figure 4 the safety device of Figure 3 in a representation according to Figure 2,

[0028] Figure 5 the triggering assembly and the use detection arrangement of the safety device in a schematic representation, and

[0029] Figure 6 a flow chart of a possible working principle of the arrangement shown in Figure 5.

[0030] Figures 1 and 2 show a precursor of a safety device which comprises a helmet in form of a full helmet, and an airbag unit. In the completely assembled state as is shown in Figures 3 and 4, at least parts of the airbag unit, namely its airbag and its inflator are covered by a cover element 26, which could also be denoted as “lid” or “cover”.

[0031] The airbag unit comprises an airbag 52 (which in this embodiment exclusively consists of a protection section being located substantially at the forehead region and side regions), an inflator 56, a filling tube 54 connecting the inflator with the airbag 52 and a triggering assembly 60 which is connected to the inflator 56 by means of an ignition cable 57.

[0032] The helmet 10 of the safety device 5 comprises a helmet body, which again comprises three parts, namely a main body 22 made of the foamed plastic material like Styrofoam, a shell 24 covering the outer surface of the main body 22 and a liner (or cushioning) 28 covering at least parts of the inner surface of the main body 22. The shell 24 is made of a hard plastic material, for example of polycarbonate. The helmet body extends in a first direction Z from a rim forming its lower end 20a to an upper end 20b and in a second direction X from a rear end portion 20c to a front end portion 20d. The helmet additionally comprises a chin strap which extends from the helmet body 20. One part 30 of this chin strap comprising a buckle 32 is shown in Figure 1 . Of course (but not shown in the sectional view), another part of the chin strap with a tongue is present.

[0033] One can further see in Figure 1 a buckling sensor 34 and a proximity sensor 40 which are parts of the airbag unit. This proximity sensor 40 can for example be placed between the main body 22 and the liner 28. Those two sensors are parts of a use detection arrangement, which will be described later, especially in view of Figures 5 and 6. The presence of such a use detection arrangement is one aspect of the invention, but the safety device also shows other features that are new and inventive over the prior art and which could at least in principle also be used independently from the presence of a use detection arrangement.

[0034] One of the features is that the airbag 52, the inflator 56 and the filling tube 54 connecting the airbag 52 with the inflator 56 are located completely outside the shell 24. This has several advantages: First, this makes the assembly easier, since the helmet 10 can essentially be made like a traditional helmet and the airbag, the filling tube (if present) and the inflator can be attached to the helmet in a subsequent step. In the embodiment shown, the filling tube 54 is a separate part, but it could also be a part of the airbag, such that the airbag would then comprise a protection section and a filling tube. Another advantage is that the structure of the helmet body remains intact when the airbag deploys. Of course, the inflator, the filling tube and the airbag are secured to the outer shell.

[0035] According to another aspect, the inflator 56 extends essentially from the upper rear end of the helmet body 20 along the outer surface of the helmet body 20 towards the front. The inflator 56 is preferably, but not necessarily, of an oblong shape and can at least in sections be a cylinder. This position and orientation of the inflator turned out to have many positive effects: First of all, it is in a position (relative to the head of the person to be protected) which is usually uncritical during a crash: It is statistically unlikely that that this region initially hits an object during a crash. Further, the position has turned out to have a positive effect on the balance of the helmet, and finally, the distance to the airbag is relatively short which leads to a quick filling of the airbag and additionally makes the use of a small inflator 56 possible.

[0036] According to another aspect, the triggering assembly 60 is placed between the main body 22 and the shell 24, especially in a lower rear region of the helmet body 20. This means that a hollow is provided between the main body 22 and the shell 24 in this region. By this measure, the triggering assembly 60 is easily accessible and mountable and well protected by the shell 24, especially against weather conditions and other environmental influences. The position is chosen additionally because at least in case of a motorcycle helmet this region of the helmet 10 rarely hits an obstacle during an accident, such that a slightly reduced thickness of the main body 22 in this region is usually not problematic. Further, this position makes the assembly easy and the triggering assembly, especially its battery, can be accessed, for example for charging purposes. The described position of the triggering assembly is especially suitable for motorcycle helmets (which can of course also be used for other purposes like scooter- or quad driving) like full helmets and jet-type helmets.

[0037] Figures 3 and 4 show another aspect, namely the presence of a single cover element (or a lid) 26 which covers all parts of the airbag unit 50 being placed outside the shell 24 of the helmet body 20. This cover element 26 could cover substantially all of the shell 24, but in the embodiment shown it does not cover the whole shell 24. In order to ensure that the airbag 52 can expand when filled with gas, the cover element 26 comprises a split-line 26a which is usually in form of a groove. In the embodiment shown, this split-line 26a extends from two ends of a hinge 26b, which can also be in form of a groove with the depth of this groove being smaller than the depth of the groove forming the split-line 26a. In an alternative (but not shown in the figures) the split-line 26a could surround the airbag 52 completely, such that an inner part of the cover element 26 covering the airbag would separate completely from the helmet body when the airbag 52 inflates. In a further (also not shown) variation this inner part of the cover element 26 could be attached (for example glued) to the airbag 52 such that it stays connected - namely via the airbag - to the airbag body even when the airbag is inflated. In a further, not shown embodiment, the cover element could separate completely from the main body when the airbag deploys.

[0038] Now, the structure and the working principle of the use detection arrangement are described in more detail in view of Figures 5 and 6. Figure 5 shows - strictly schematically - the triggering assembly 60 and the use detection arrangement 70. In the embodiment shown, the triggering assembly and the use detection arrangement 70 partially “overlap”, because they use the same controller / ECU 64.

[0039] As has already been discussed briefly, the triggering assembly 60 comprises a controller 64, a crash sensor 66 in communication with the controller 64 and a battery 62. The crash sensor is not necessarily a physically separate part; it can be integrated into the controller 64 whose features have to be understood functionally in the first place. It is possible that the battery 62 is not permanently connected to the controller 64, such that it can be removed for example for charging purposes. But, in an operational state, the battery must be present. The crash sensor 66 is most often in form of an acceleration sensor, such that an unusual acceleration or deceleration usually taking place before the helmet hits an obstacle due to an accident can be detected. If such an unusual acceleration is detected, the inflator 56 is triggered by the controller (or more general: by the triggering assembly 60) if the use detection arrangement is in its second state (see below).

[0040] The use detection arrangement 70 comprises the proximity sensor 40 and the buckling sensor 44. In a simpler embodiment, only one of those sensors could be present, but the use of two sensors makes it very unlikely that a likely worn state is detected although the helmet is not being worn. Both sensors are electrically connected to the controller / ECU 64.

[0041] Figure 6 shows a possible and preferred working principle of the use detection arrangement 70 shown in Figure 5. The flow chart of Figure 5 starts in a state in which the helmet is not worn and the use detection arrangement 70 is thus in a first state in which the triggering assembly is disabled. As long as the buckle 32 does not change from an open state to a closed state, the use detection arrangement 70 remains in its first state. When the buckle 32 changes from its open state to its closed state, it is next checked by the controller 64 if the proximity sensor 40 detects an object. If no object is detected, the use detection arrangement 70 remains in its first state. But, if an object is detected, it is assumed that the helmet 10 is worn and the use detection arrangement 70 turns into its second state, in which the triggering assembly is enabled. The use detection arrangement remains in this second state until the buckle changes from its closed state to its open state.

[0042] As long as the use detection arrangement is in its first state, it is possible that the triggering assembly is in an energy saving resting state, for example by deactivating the crash sensor.

[0043] Figure 7 shows a precursor similar to the precursor shown in Figures 1 and 2 but in a more detailed representation. One can see that parts of the airbag unit, namely its inflator 56, its filling tube 54 and its airbag 52 are symmetrically arranged in regard of the symmetry plane of the helmet body which extends in the XZ-plane, as is also the case in the embodiment described above.

[0044] List of reference numbers

[0045] 5 safety device

[0046] 10 helmet

[0047] 20 helmet body

[0048] 22 main body

[0049] 24 shell

[0050] 26 cover element I lid I cover

[0051] 26a split-line

[0052] 26b hinge

[0053] 28 liner / cushioning

[0054] 30 part of chin strap

[0055] 32 buckle of chin strap

[0056] 34 buckling sensor

[0057] 40 proximity sensor

[0058] 50 airbag unit

[0059] 52 airbag

[0060] 54 filling tube

[0061] 56 inflator

[0062] 57 ignition cable

[0063] 60 triggering assembly

[0064] 62 battery

[0065] 64 controller / ECU

[0066] 66 crash sensor I acceleration sensor

[0067] 70 use-detection arrangement

Claims

Claims1. A safety device for the head of a human, comprising a helmet (10) having a helmet body (20) and an airbag unit (50) attached to said helmet body (20), said airbag unit (50) comprising: an airbag (52) having at least one protection section, an inflator (56) being in fluid communication to said airbag, a triggering assembly (60) for triggering said inflator (56), said triggering assembly (60) comprising at least one crash sensor (66) and a battery (62) at least when the triggering assembly (60) is in an operational state, characterized in that airbag unit (50) further comprises a use detection arrangement (70) for distinguishing between an unworn state and likely worn state of the helmet body (20), such that the use detection arrangement (70) is in a first state when it detects the unworn state and in a second state when it detects the likely worn state, said use detection arrangement (70) comprising at least one sensor, wherein, when the use detection arrangement (70) is in its first state, the triggering of the inflator (56) by the triggering assembly (60) is disabled, and when the use detection arrangement (70) is in its second state, the triggering assembly (60) is enabled to trigger the inflator (56) when a crash is detected by the triggering assembly (60).

2. The safety device of claim 1 , characterized in that the triggering assembly (60) is in an energy saving resting state when the use detection arrangement (70) is in its first state and that the triggering assembly (60) is in an active state when the use detection arrangement is in its second state.

3. The safety device of claim 1 or claim 2, characterized in that the helmet (10) further comprises a chin strap (30) with a buckling device, such that the chins strap (30) has an open state and a closed state, whereinthe buckling device comprises a buckling sensor (34) being a part of the use detection arrangement (70) and the use detection arrangement (70) is in its first state, when the buckling sensor (34) detects the open state.

4. The safety device of claim 3, characterized in that the use detection arrangement (70) is in its second state when the buckling sensor (34) detects the closed state.

5. The safety device of any one of claims 1 to 3, characterized in that the use detection arrangement (70) comprises a proximity- and / or contact sensor (40) for detecting the presence of an object at or near an inner surface of the helmet body (20), wherein the use detection arrangement is in its first state when the proximity- and / or contact sensor (40) does not detect the presence of an object at or near an inner surface of the helmet body (20).

6. The safety device of claim 5, characterized in that the use detection arrangement (70) is in its second state when the proximity- and / or contact sensor (40) detects the presence of an object at or near an inner surface of the helmet body.

7. The safety device of claims 3 and 5, characterized in that use detection arrangement (70) is only in its second state when buckling sensor (34) detects the closed state and the proximity- and / or contact sensor (40) detects the presence of an object at or near an inner surface of the helmet body (20).

8. The safety device according to any one of the preceding claims, characterized in that the helmet body (20) extends in a first direction (Z) from a rim forming its lower end (20a) to an upper end (20b) and in a second direction (X) from a rear end portion (20c) to a front end portion (20d).

9. The safety device of claim 8, characterized in that the inflator (56) has an oblong shape and extends from a first end portion to a second end portion, whereinthe first end portion of the inflator comprises a connector being electrically connected to the triggering assembly(60), the second end portion of the inflator comprises a gas outlet, and the first end portion of the inflator (56) is located at the rear end portion (20c) of the helmet body (20) remote from the lower end (20a) of the helmet body (20) and the inflator (56) extends from its first end portion along an upper surface of the helmet body (20) towards the front end portion of the helmet body (20).

10. The safety device according to claim 9, characterized in that the helmet body (20) comprises a symmetry plane and that the inflator (56) is located in said symmetry plane.1 1. The safety device of claim 9 or claim 10, characterized in that the protection section of the airbag (52) is located at least at a forehead area of the helmet body (20), wherein it preferably extends from the forehead area to the sides.

12. The safety device of any one of claims 9 or 11 , characterized in that at least the battery (62) of the triggering assembly (60), preferably the whole triggering assembly (60), is located between the first end portion of the inflator (56) and the lower end (20a) of the helmet body (20).

13. The safety device according to any one of the preceding claims, characterized in that the helmet body (20) comprises a main body (22) made from a foamed material and a rigid shell (24) covering the main body (22) on the outside of the main body (22), wherein at least the protection section of the airbag, preferably the whole airbag (52) and the inflator (56), is located outside the rigid shell (24).

14. The safety device of claim 13, characterized in that at least the battery (62) of the triggering assembly, preferably the whole triggering assembly (60), is located between the main body (22) and the rigid shell (24).

15. The safety device of claim 13 or claim 14, characterized in that at least the parts of the airbag unit (50) being located outside the rigid shell (24) are covered by a single cover element (26).

16. The safety device according to claim 15, characterized in that cover element (26) comprises a split-line (26a).

17. The safety device according to claim 15, characterized in that the cover element (26) de-attached completely from the helmet body (20) when the airbag (52) deploys.

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