Head protection assembly

Abstract

A head assembly (10) for protection against rotational impact comprising a first and second strap layer (20A, 20B). Also described is a method of operating a head protection assembly as well as a method of retrofitting a head protection assembly with a first and second strap layer.

Description

[0001]HEAD PROTECTION ASSEMBLY FIELD The present disclosure relates to a head protection assembly for protection against rotational impact comprising a first and second strap layer. The present disclosure further relates to a method of operating a head protection assembly comprising a first and second strap layer as well as to a method of retrofitting a head protection assembly comprising a first and second strap layer to a personal protective equipment. BACKGROUND Personal protective equipment, e. g. protective helmets are commonly worn by people such as firefighters, construction workers, and athletes to shield their heads from flying, falling objects or impacts during collisions or falls. The helmet usually includes a rigid protective shell or hard shell of impact resistant material. For some applications, the helmets may also include visors or face shields to protect the eyes or the entire face of the wearer, and may further include a respirator to protect the wearer's respiratory system. Personal protective equipment may also include respiratory devices with a shell to provide head protection. Various government agencies and industry organizations define certain requirements and standards for protective gear, including helmets and respirators. In the United States, for example, the National Institute of Occupational Safety and Health (NIOSH) certifies certain safety equipment for the workplace and the American National Standards Institute (ANSI) recommends voluntary consensus industry standards. Other agencies and organizations arounSSd the world also establish safety standards for helmets and respirators. For personal protective equipment, in particular protective helmets, some of these standards relate to impact energy attenuation, penetration resistance, force transmission, stiffness, flammability, and head coverage. To meet these safety requirements and standards, protective helmets usually comprise a rigid outer shell or hard shell of metal or plastic and a suspension system inside the shell. The suspension system serves many purposes, including providing a proper fit of the helmet to the wearer's head, holding the inner part of the helmet away from the wearer's head, distributing the weight of the helmet over a larger area of the wearer's head, and attenuating the force transferred to the wearer's head upon impact of an object with the outer helmet shell. Such a force attenuation may also be referred to as shock absorption. Suspension systems often comprise a headband attached to a crown support layer which includes crisscrossing crown straps and a crown pad. Although providing some shock absorbing properties, there might be situations requiring additional impact protection. For example, an impact onto the protective helmet may also include the acting of rotational forces such that rotation of the protective helmet relative to the head of a wearer may occur. However, additional protection may be provided, e. g. by a foam liner between the inner shell and suspension of the helmet to provide additional impact protection. Such solutions may be bulky and may limit the fit of such helmets for certain users, in particular these solutions typically do not address the impact of rotational forces. SUMMARY A head protection assembly for protection against impacts causing rotational forces to the head of the wearer comprising a first strap layer comprising a plurality of first flexible straps and a second strap layer comprising a plurality of second flexible straps. The flexible straps of the first and second strap layers are connected to each other. The flexible straps of each of the first and second strap layers form an intersection comprising a center point. The first and second strap layers are superimposed. The head protection layer assembly exhibits a first and a second condition. In the first condition of the head protection assembly - the center point of the first strap layer is substantially coincident with the center point of the second strap layer. In the second condition of the head protection assembly – the center point of the first strap layer is offset relative to the center point of the second strap layer. A rotational force impacting onto the head protection assembly will move the shell of a personal protective equipment, e.g. a protective helmet or others as mentioned in the present disclosure, comprising such a head protection assembly. As the first and second strap layers are movably over a pivot in each connection point to the shell, the shell can move without rotating wearers head due to the movement absorbed by the two layers of strap layers, in particular without movement of the first strap layer which is in contact to the wearer´s head. This prevents the head of the wearer from being rotated upon the impact causing a rotational force onto the head protection assembly. This is beneficial as rotation of the wearer´s head may otherwise lead to an uncomfortable situation or even injury of the wearer caused by the rapidly rotation inflicted to the wearers head. The present disclosure thus provides for a simple, compact, and reliable protection against the rotation of the wearer´s head upon impact causing a rotational force onto a personal protective equipment with such a head protection assembly. This and other embodiments are further described below. BRIEF DESCRIPTION OF THE DRAWINGS Fig.1 is a schematic perspective view of a personal protective equipment with a head protection assembly according to the present disclosure; Fig.2 is a schematic perspective view of a personal protective equipment with a head protection assembly according to the present disclosure; Fig.3 is a schematic bottom view of a personal protective equipment with a head protection assembly according to the present disclosure; Fig.4 is a schematic perspective view of the first and second strap layers of the head protection assembly according to the present disclosure arranged on the head of a wearer, wherein the head protection assembly is in the first condition; Fig.5 is a schematic perspective view of the first and second strap layers of the head protection assembly according to the present disclosure arranged on the head of a wearer, wherein the head protection assembly is in the second condition; Fig.6 represent a schematic cross-sectional view of the first and second strap layers of the head protection assembly along the line B-B as indicated in Fig.4; Fig.7 represent a schematic cross-sectional view of the first and second strap layers of the head protection assembly along the line A-A as indicated in Fig.4; Fig.8 is a schematic perspective view of the first and second strap layers of the head protection assembly according to an embodiment of the present disclosure showing loops engaging with receptacles; Fig.9 is a schematic perspective view of a welding helmet according to the present disclosure; Fig.10 is a schematic perspective view of a respiratory device with the head protection assembly according to the present disclosure; Fig.11 is a schematic perspective view of a face shield with the head protection assembly according to the present disclosure; Fig. 12 is a schematic top view of the second strap layer of the head protection assembly according to an embodiment of the present disclosure with an additional shock absorber layer with two flexible straps assembled to a deformable element. It is to be understood that the embodiments may be utilized, and structural changes may be made without departing from the scope of the invention. The figures are not necessarily to scale. Like numbers used in the figures refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number. DETAILED DESCRIPTION There is a need to improve the protection provided by a personal protective equipment worn by users to protect their head against external impacts. In particular, it is an object of the present disclosure to provide protection with regard to external impact protection including the impact caused by rotational forces to the head of the wearer. In a first aspect, the present disclosure relates to a head protection assembly for protection against impacts causing rotational forces to the head of the wearer comprising a first strap layer comprising a plurality of first flexible straps and a second strap layer comprising a plurality of second flexible straps. The flexible straps of the first and second strap layers are connected to each other. The flexible straps of each of the first and second strap layers form an intersection comprising a center point. The first and second strap layers are superimposed. The head protection layer assembly exhibits a first and a second condition. In the first condition of the head protection assembly - the center point of the first strap layer is substantially coincident with the center point of the second strap layer. In the second condition of the head protection assembly – the center point of the first strap layer is offset relative to the center point of the second strap layer. A rotational force impacting onto the head protection assembly will move the shell of a personal protective equipment, e.g. a protective helmet or others as mentioned in the present disclosure, comprising such a head protection assembly. As the first and second strap layers are movably over a pivot in each connection point to the shell, the shell can move without rotating wearers head due to the movement absorbed by the two layers of strap layers, in particular without movement of the first strap layer which is in contact to the wearer´s head. This prevents the head of the wearer from being rotated upon the impact causing a rotational force onto the head protection assembly. This is beneficial as rotation of the wearer´s head may otherwise lead to an uncomfortable situation or even injury of the wearer caused by the rapidly rotation inflicted to the wearers head. The present disclosure thus provides for a simple, compact, and reliable protection against the rotation of the wearer´s head upon impact causing a rotational force onto a personal protective equipment with such a head protection assembly. Personal protective equipment (PPE) within the meaning of the present disclosure is understood as assemblies for protective users or workers in a certain environment which may have some negative impact to the user or worker. PPE typically includes wearables like hearing protection, jackets, helmets of different kinds or the like. For the present disclosure, PPE mainly includes protective helmets, welding helmets, face shields or respiratory devices. Such PPE typically comprises a shell, preferably a hard shell, and is worn on or at the head of a user or worker in order to prevent the user or worker from negative impacts of object falling onto the head of a user or worker, which may cause injuries to the user or worker because of the kinetic energy of a falling object is being transmitted to the user´s head without any attenuation or shock absorption otherwise. The shell of a PPE may exhibit some rigidity and typically has flexible straps connected to the inside of the hard shell of the personal protective equipment and contacting the user´s or worker´s head to maintain the position of the PPE on the user´s or worker`s head. Such straps may form a head gear. Movably connected of the strap layers to the shell of the head protection assembly within the meaning of the present disclosure means that some movement is achieved of the shell relative to the strap layer or layers, i.e. without moving the strap layer, in particular the first strap layer which – in use – is in contact with the wearer´s head. In a second aspect, the present disclosure relates to a method of operating a head protection assembly according to the present disclosure. The method comprises the steps of: providing a personal protective equipment with a head protection assembly according to the present disclosure, donning the head protection assembly onto a wearer´s head, and impacting a rotational force onto the shell of the personal protective equipment, thereby offsetting the center point of the first strap layer relative to the center point of the second strap layer. A rotational force impacting onto the head protection assembly will move the shell of a personal protective equipment, e.g. a protective helmet or others as mentioned in the present disclosure, comprising such a head protection assembly. As the first and second strap layers are movably over a pivot in each connection point to the shell, the shell can move without rotating wearers head due to the movement absorbed by the two layers of strap layers, in particular without movement of the first strap layer which is in contact to the wearer´s head. This prevents the head of the wearer from being rotated upon the impact causing a rotational force onto the head protection assembly. This is beneficial as rotation of the wearer´s head may otherwise lead to an uncomfortable situation or even injury of the wearer caused by the rapidly rotation inflicted to the wearers head. The present disclosure thus provides for a simple, compact, and reliable protection against the rotation of the wearer´s head upon impact causing a rotational force onto a personal protective equipment with such a head protection assembly. In a third aspect, the present disclosure relates to a method of retrofitting a personal protective equipment with a head protection assembly comprising a first and second strap layer for protection against rotational impact according to the present disclosure. Each of the first and second strap layers comprises a plurality of flexible straps. The flexible straps of the first and second layers are connected to each other forming loops. The flexible straps of each of the first and second strap layers form an intersection comprising a center point. The first and second strap layers are superimposed. The personal protective equipment comprises a shell. The method comprises the steps of: providing a first and second strap layer, optionally removing the existing strap layer from the personal protective equipment, attaching the first and second strap layer to an inner surface of the shell of the personal protective equipment. The loops of the first and second straps engage with connection elements such that the loops are arranged around receptacles of the connection elements. A rotational force impacting onto the head protection assembly will move the shell of a personal protective equipment, e.g. a protective helmet or others as mentioned in the present disclosure, comprising such a head protection assembly. As the first and second strap layers are movably over a pivot in each connection point to the shell, the shell can move without rotating wearers head due to the movement absorbed by the two layers of strap layers, in particular without movement of the first strap layer which is in contact to the wearer´s head. This prevents the head of the wearer from being rotated upon the impact causing a rotational force onto the head protection assembly. This is beneficial as rotation of the wearer´s head may otherwise lead to an uncomfortable situation or even injury of the wearer caused by the rapidly rotation inflicted to the wearers head. The present disclosure thus provides for a simple, compact, and reliable protection against the rotation of the wearer´s head upon impact causing a rotational force onto a personal protective equipment with such a head protection assembly. In a fourth aspect, the present disclosure relates to a personal protective equipment comprising the head protection assembly according to the present disclosure. The personal protective equipment comprises a shell. The first and second strap layers are connected to an inner surface of the shell. Such a head protection assembly is beneficial as the arrangement of the first and second strap layer in such personal protective equipment provides for an easy and reliable protection therein against the impact of rotational forces. In one embodiment, the personal protective equipment includes a protective helmet, a face shield, a respiratory device or a welding helmet. This is beneficial as the inclusion of the head protection assembly according to such a personal protective equipment provides for additional safety as laid out above for the head protection assembly. In one embodiment, the first strap layer of the head protection assembly is – in use – in contact with the head of a wearer of the head protection assembly. Such a first strap layer provides for support and fitting of the head protection assembly to the wearer´s head in use. In another embodiment, at least one of the flexible straps of the first and second strap layer of the head protection assembly are substantially coincident relative to each other. This is beneficial as a compact and reliable construction of the head protection assembly is achieved thereby. In yet another embodiment, the first and the second strap layer of the head protection assembly each comprises 4 straps. This provides for a good fit and support of the first layer to the wearer´s head in use on the one hand and for a robust and reliable connection of the layers to the shell of a personal protective equipment with such a head protection assembly on the other hand. In a further embodiment, the connected straps of the first and second strap layer of the head protection assembly form a loop. Such a loop is beneficial as it provides for a reliable connection to the shell of the head protection assembly and connection mechanisms thereof. Also, an easy connection providing some movement of the straps relative to the head protection assembly is achieved thereby. In yet a further embodiment, the head protection assembly comprises connection elements configured and arranged to connect to the shell of a personal protective equipment and wherein the straps of the first and second strap layer are configured and arranged to movable connect to the connection elements. Such connection elements provide for an easy and reliable connection between the strap layers and the shell of the head protection assembly. In certain embodiments, where the first and second strap layer of the head protection assembly form a loop and where the head protection assembly comprises connection elements, the connection elements comprise rod-like receptacles configured and arranged such that the loops of the straps are arranged around the receptacles. Such a connection between the shell of the head protection assembly and the strap layers provides for an easy and robust connection while allowing some movement of the straps relative to the head protection assembly. In one embodiment, the head protection assembly is brought from the first to the second position by a rotational force impacting on the head protection assembly. A rotational force impacting onto the head protection assembly will move the shell of a personal protective equipment, e.g. a protective helmet or others as mentioned in the present disclosure, comprising such a head protection assembly. As the first and second strap layers are movably over a pivot in each connection point to the shell, the shell can move without rotating wearers head due to the movement absorbed by the two layers of strap layers, in particular without movement of the first strap layer which is in contact to the wearer´s head. This prevents the head of the wearer from being rotated upon the impact causing a rotational force onto the head protection assembly. This is beneficial as rotation of the wearer´s head may otherwise lead to an uncomfortable situation or even injury of the wearer caused by the rapidly rotation inflicted to the wearers head. The present disclosure thus provides for a simple, compact, and reliable protection against the rotation of the wearer´s head upon impact causing a rotational force onto a personal protective equipment with such a head protection assembly. In another embodiment, the center points of the first and second strap layers of the head protection assembly are offset by a distance d in the second condition. The impact of a rotational force will offset the center points for a distance d. This is beneficial as rotation of the wearer´s head may otherwise lead to an uncomfortable situation or even injury of the wearer caused by the rotated head. The present disclosure thus provides for a simple, compact and reliable protection against the rotation of the wearer´s head upon impact of a rotational force onto the head protection assembly. In yet another embodiment, the second strap layer of the head protection assembly additionally comprises a shock absorber layer comprising a deformable element around which the straps of the second strap layer are tightly wrapped such that pulling at the straps of the second strap layer deforms the deformable element, wherein the intersection is formed by the deformable element comprising the center point. Such an additional shock absorber layer in the second strap layer of the head protection assembly is beneficial as the head protection assembly also provides protection against other impacts than rotational forces, e.g. object falling onto the head protection assembly from the above, which may otherwise lead to uncomfortable situations or even injuries of the wearer of the head protection assembly. The deformable element of the shock absorber takes the kinetic energy from the impact while being deformed and thereby prevents the impact to the wearer. In one embodiment of the method of retrofitting a head protection assembly, the head protection assembly exhibits a first and a second condition. In a first condition of the head protection assembly, the center point of the first strap layer is substantially coincident with the center point of the second strap layer. In the second condition of the head protection assembly, the center point of the first strap layer is offset relative to the center point of the second strap layer. A rotational force impacting onto the head protection assembly will move the shell of a personal protective equipment, e.g. a protective helmet or others as mentioned in the present disclosure, comprising such a head protection assembly. As the first and second strap layers are movably over a pivot in each connection point to the shell, the shell can move without rotating wearers head due to the movement absorbed by the two layers of strap layers, in particular without movement of the first strap layer which is in contact to the wearer´s head. This prevents the head of the wearer from being rotated upon the impact causing a rotational force onto the head protection assembly. This is beneficial as rotation of the wearer´s head may otherwise lead to an uncomfortable situation or even injury of the wearer caused by the rapidly rotation inflicted to the wearers head. The present disclosure thus provides for a simple, compact, and reliable protection against the rotation of the wearer´s head upon impact causing a rotational force onto a personal protective equipment with such a head protection assembly. In a further embodiment of the method of retrofitting the head protection assembly, the first and the second strap layer of the head protection assembly each comprises 4 straps. This provides for a good fit of the first layer to the wearer´s head in use on the one hand and for a robust and reliable connection of the layers to the shell of the head protection assembly on the other hand. It is understood that – although described here explicitly only for a part of the above embodiments of the head protection assembly - that all of the above described embodiments of the head protection assembly are conceivable for the method of operating and for the method of retrofitting the head protection assembly. The invention was described in various embodiments above. It is understood by a person skilled in the art, that one of, several of or all the above-mentioned embodiments can be combined with each other. The invention will now be described in more detail with reference to the following Figures exemplifying particular embodiments of the invention: Fig.1 is a schematic perspective view of a personal protective equipment with the head protection assembly 10, in the example shown a protective helmet 100, comprising a hard shell 110 and the first and second strap layers 20A, 20B (not visible here, please see Fig. 3) according to the present disclosure. Figs.2 is schematic perspective view of the personal protective equipment with the head protection assembly 10, in the example shown a protective helmet 100, with the first and second strap layers 20A, 20B (arranged inside of the hard shell 110 of the protective helmet 100, which has been illustrated as transparent for this view). As can be seen, the first and second strap layers 20A, 20B are arranged such that a distance occurs between the inner surface of the hard shell 110 of the personal protective equipment 100 and the second strap layer 20B of the head protection assembly 10. Fig.2 further shows the connection elements 40 for receiving the straps of the first and second strap layer 20A, 20B (only one of the four connection elements is labelled with 40 here). As can be seen from Fig.2, the head protection assembly 10 is in a first condition, where the first and second strap layer 20A, 20B are superimposed and are substantially coincident relative to each other. Fig.3 is a schematic bottom view of the personal protective equipment, here a protective helmet 10, with the head protection assembly 10 comprising the first and second strap layer 20A, 20B attached to the inside of the hard shell 110 of the protective helmet 100. As can be seen, the straps of the first and second strap layer 20A, 20B form loops which engage with corresponding receptacle of the connection elements 40 connected to the hard shell 110 of the protective helmet 100. Fig.3 shows the connection elements 40 in the connected condition. It is noted that the connection elements 40 may provide a release connection such that the first and second strap layer 20A, 20B can be removed from the protective helmet 100, e. g. for replacement by a different protection means such as a shock absorber layer or another head gear (not shown or described here). It is also noted that the protective helmet 100 may initially not have had a first and second strap layer 20A, 20B according to the present disclosure. Due to the releasable connection elements 40, the first and second strap layer 20A, 20B may have been retrofitted to the protective helmet 100 by removing the initial layer, if present, e. g. a standard head gear without any specific protective function, by disconnecting its connection elements from the protective helmet 100 and replacing the initial layer with the first and second strap layer 20A, 20B according to the present disclosure by connecting the connection elements 40 with the protective helmet 100. It is also conceivable that the connection between the connection elements 40 and the protective helmet 100 is permanent, i. e. not releasable or disconnectable. Fig.4 is a schematic perspective view of a head protection assembly 10 according to the present disclosure being in a first condition showing the first and second strap layer 20A, 20B in greater detail. As can be seen, the first and second strap layer 20A, 20B have been arranged on a wearer´s head 500. Other parts of the head protection assembly or the protective helmet 100, e.g. the shell, have been omitted in this view for the sake of simplifying the view. The first strap layer 20A is in contact with the wearer´s head 500 and comprises 4 flexible straps 22A, 24A, 26A, 28A forming an intersection 30A with center point 32A. Similarly, the second strap layer 20B which is superimposed to the first strap layer 20A comprises 4 flexible straps 22B, 24B, 26B, 28B forming an intersection 30B with center point 32B. In the view of Fig.4, the center points 32A, 32B of the first and second strap layer 20A, 20B are substantially coincident to each other because the head protection assembly is in the first condition. Fig.4 further indicates cut lines A-A and B-B for which the cross-sectionals views are shown and described under Figs.6 and 7. Fig.5 is a schematic perspective view of the first and second strap layers 20A, 20B of the head protection assembly 10 according to the present disclosure arranged on the head 500 of a wearer, wherein the head protection assembly 10 is in the second condition. The first and second strap layers 20A, 20B each comprises – similar to Fig.4 – four flexible straps 22A, 24A, 26A, 28A and 22B, 24B, 26B, 28B forming intersections 30A, 30B having center point 32A, 32B. Different to the view of Fig.4, as mentioned above, the head protection assembly 10 is in the second condition because of the impact of a rotational force onto the personal protective equipment and the head protection assembly 10, respectively. In this second condition, the center points 32A, 32B are not substantially coincident to each other any longer, but these are offset relative to each other by a distance d as indicated in Fig.5. As the first and second strap layers 20A, 20B are movably connected to the shell 110 (not shown here) of the head protection assembly 10, e.g. in a protective helmet 100 (not shown here), the shell 110 with the protective helmet 100 has moved relative to the wearer´s head 500. It is noted that the first strap layer 20A, which is in contact with the wearer´s head 500, has not moved relative to the wearer´s head 500, but is still in the initial position on the wearer´s head 500. This provides that the wearer is being prevented from the impact of the rotational force acting on the head protection assembly 10. In other words, the rotational force impacting on the head protection assembly 10 may thus cause rotational movement of the head protection assembly 10, but not of the wearer´s head 500. Fig.6 represent a schematic cross-sectional view of the first and second strap layers 20A, 20B of the head protection assembly 10 along the line B-B as indicated in Fig.4. As can be seen in Fig.6, the second strap layer 20B with the exemplarily shown strap 28B is superimposed to the first strap layer 20A with the exemplarily shown strap 28A. Fig.6 further shows the connection elements 40 and the connection to the straps then more details. As can be seen, the connection element 40 comprises a rod-like receptable 42, which engages with the loop 44 formed by the straps 28A, 28B of the first and second strap layers 20A, 20B. Fig.7 represent a schematic cross-sectional view of the first and second strap layers 20A, 20B of the head protection assembly 10 along the line A-A as indicated in Fig.4. As can be seen in Fig.7, the second strap layer 20B with the exemplarily shown strap 28B is superimposed to the first strap layer 20A with the exemplarily shown strap 26A. Similar to Fig.6, the connection element 40 comprises a rod-like receptable 42, which engages with the loop 44 formed by the straps 28A, 28B of the first and second strap layers 20A, 20B. Fig.8 is a schematic perspective view of the first and second strap layers 20A, 20B of the head protection assembly 10 according to an embodiment of the present disclosure showing loops 44 engaging with receptacles 42 of the connection elements 40 of the shell 110 of the head protection assembly 10. The center points 32A, 32B of the intersections 30A, 30B have not been indicated in this view (please see Figs.4 and 5). It is noted that the center points 32A, 32B of intersections 30A, 30B of the first and second strap layers 20A, 20B are shown in a more distant manner and not representing the first or second condition of the head protection assembly 10 as shown and described above. As can be seen in Fig.8, the loops 44 formed by the straps 28A, 28B of the first and second strap layers 20A, 20B engage with the rod-like receptacles 42 of the connection elements 40 (not shown here) such that the loops 44 are arranged around the receptacles 42. Other ways of connecting the first and second strap layers 20A, 20B, although not shown or described here, are conceivable. It is noted that the connection is only exemplarily shown and described for one of the four connection elements here. It is clear to the skilled person that the other connections are arranged similarly as shown and described here. Fig.9 is a schematic perspective view of a welding helmet 200 with the head protection assembly 10 according to the present disclosure. As can be seen in Fig.9, the welding helmet 200 comprises a hard shell 210, a protective visor 220 and the first and second strap layer 20A, 20B according to the present disclosure. The welding helmet 200 further comprises the head protection assembly 10 according to the present disclosure, which is only schematically and partially indicated here. Fig.10 is a schematic perspective view of a respiratory device 300 with the head protection assembly 10 according to the present disclosure. Fig.10 shows the respiratory device 300 comprising a hard shell 310, a protective visor 320 and an air supply connection 330 connecting the respiratory device 300 with an air supply unit (not shown here). The respiratory device 300 further comprises the head protection assembly 10 according to the present disclosure, which is only schematically and partially indicated here. Fig.11 is a schematic perspective view of a face shield 400 with the head protection assembly 10 according to the present disclosure. Fig.6 shows the face shield 400 comprising a hard shell 410 and a protective visor 420. The face shield 400 further comprises the head protection assembly 10 according to the present disclosure, which is only schematically and partially indicated here. Figure 12 is a schematic top view of an embodiment of the head protection assembly 10 according to the present disclosure additionally having a shock absorber assembly. The shock absorber assembly comprises a deformable element 12 and has an elongated extension. The deformable element 12 comprises a main body and may have an opening formed therein (not shown here). The flexible straps 22B’, 224B’, 26B’, 28B’ of the second strap layer 20B of the head protection assembly 10 are arranged at the deformable element 12 such that a middle portion of the flexible straps 22B’, 224B’, 26B’, 28B’ is tightly wrapped around the deformable element 12. The middle portion of the straps 22B’, 224B’, 26B’, 28B’ is supported by the deformable element 12. The straps 22B’, 224B’, 26B’, 28B’ further are arranged such that twisted portions are provided sat which the strap 22B’, 224B’, 26B’, 28B’ turns from a first major surface of the deformable element 12 to a second major surface opposite to the first major surface such that a part of the middle portion of the strap is on the opposite second major surface (underneath the deformable element 12 and thus not visible here) and vice versa. As can be seen, the middle portions of the straps 22B’, 224B’, 26B’, 28B’ overlap with each other on the front side and on the rear side (not visible). Pulling at the straps 22B’, 224B’, 26B’, 28B’ deforms the deformable element 12 such that the deformable element 12 undergoes a change in shape and / or size. A shock absorption introduced by the flexible straps 22B’, 224B’, 26B’, 28B’, e.g. caused by an impact of an object falling from the above and hitting the head protection assembly 10.

Claims

CLAIMS 1. Head protection assembly for protection against rotational impact comprising a. a first strap layer comprising a plurality of first flexible straps; and, b. a second strap layer comprising a plurality of second flexible straps, wherein the flexible straps of the first and second strap layers are connected to each other; wherein the flexible straps of each of the first and second strap layers form an intersection comprising a center point; wherein the first and second strap layers are superimposed; wherein the head protection assembly exhibits a first and a second condition; wherein, the first condition is where the center point of the first strap layer is substantially coincident with the center point of the second strap layer; and, wherein the second condition is where the center point of the first strap layer is offset relative to the center point of the second strap layer.

2. The head protection assembly according to the preceding claim, wherein the first strap layer is, while in use, in contact with the head of a wearer of the head protection assembly.

3. The head protection assembly according to any one of the preceding claims, wherein at least one of the flexible straps of the first and second strap layer are substantially coincident relative to each other.

4. The head protection assembly according to any one of the preceding claims, wherein the first and the second strap layers each comprise 4 straps.

5. The head protection assembly according to any one of the preceding claims, wherein the connected straps of the first and second strap layers form a loop.

6. The head protection assembly according to any one of the preceding claims, wherein the head protection assembly comprises connection elements configuredand arranged to connect to the shell of a personal protective equipment and wherein the straps of the first and second strap layer are configured and arranged to movable connect to connection elements.

7. The head protection assembly according to claim 5 and 6, wherein the connection elements receptacles comprise rod-like receptacle configured and arranged such that the loops of the straps are arranged around the receptacles.

8. The head protection assembly according to any of the preceding claims, wherein the head protection assembly is brought from the first to the second position by a rotational force impacting on the head protection assembly.

9. The head protection assembly according to any one of the preceding claims, wherein the center points of the first and second strap layers are offset by a distance d in the second condition.

10. The head protection assembly according to any one of the preceding claims, wherein the second strap layer additionally comprises a shock absorber assembly comprising a deformable element around which the straps of the second strap layer are tightly wrapped such that pulling at the straps of the second strap layer deforms the deformable element, wherein the intersection is formed by the deformable element comprising the center point.

11. A personal protective equipment comprising the head protection assembly according to any one of the preceding claims, wherein the personal protective equipment comprises a shell and wherein the first and second strap layers are connected to an inner surface of the shell, wherein the personal protective equipment optionally includes a protective helmet, a face shield, a respiratory device or a welding helmet.

12. Method of operating a head protection assembly according to any of the claims 1 to 10, the method comprising the steps of:a) providing a personal protective equipment with a head protection assembly according to any of the preceding claims; b) donning the head protection assembly onto a wearer´s head; and, c) impacting a rotational force onto the shell of the personal protective equipment, thereby offsetting the center point of the first strap layer relative to the center point of the second strap layer.

13. A method of retrofitting a personal protective equipment a head protection assembly comprising a first and second strap layer for protection against rotational impact according to any one of claims 1 to 10, wherein each of the first and second strap layers comprises a plurality of flexible straps; wherein the flexible straps of the first and second layers are connected to each other forming loops; wherein the flexible straps of each of the first and second strap layers form a intersection comprising a center point; wherein the first and second strap layers are superimposed; wherein the personal protective equipment comprises a shell; the method comprises the steps of: a) providing a first and second strap layer; b) optionally removing the existing strap layer from the personal protective equipment; and, c) attaching the first and second strap layer to an inner surface of the shell of the personal protective equipment, wherein the loops of the first and second straps engage with connection elements such that the loops are arranged around the receptacles of the connection elements.

14. The method according to claim 13, wherein the head protection assembly exhibits a first and a second condition, wherein the first condition is where the center point of the first strap layer is substantially coincident with the center point of the second strap layer, and wherein the second condition is where the center point of the first strap layer is offset relative to the center point of the second strap layer.

15. The method according to any one of claims 13 or 14, wherein the first and second strap layers each comprises 4 straps.

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