The present disclosure relates to a shock absorber assembly for a personal protective equipment comprising a deformable element and to a deformable element for such a shock absorber assembly. The present disclosure furthermore relates to a method of retrofitting such a shock absorber assembly to a personal protective equipment, preferably a protective helmet. The present disclosure moreover relates to a protective helmet, a welding helmet, a face shield or a respiratory device comprising a hard shell and such a shock absorber.
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 or falling objects. 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.
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 around 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 assembly which includes crisscrossing crown straps and a crown pad. Although providing some shock absorbing properties, there might be situations requiring additional impact protection. 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.
It is therefore a need to improve the protection provided by a personal protective equipment, in particular of protective helmets worn by users to protect their head against external impacts. In particular, it is an object of the present disclosure to provide an improved personal protective equipment with regard to external impact protection.
In a first aspect, the present disclosure relates to a shock absorber assembly for a personal protective equipment. The shock absorber assembly comprises a deformable element exhibiting a mechanical resistance against deformation and a flexible strap comprising a middle portion and two free end portions facing away from each other. The middle portion is tightly wrapped around the deformable element such that pulling the free end portions away from each other deforms the deformable element. Pulling the free end portions away from each other leads to an increase of the length s of at least one of the free end portions upon deformation of the deformable element. The kinetic energy of a falling object is introduced to the personal protective equipment, onto which the object falls. At the impact of the object, the kinetic energy is introduced to the personal protective equipment and is further being transmitted to the straps connected to the hard shell of the personal protective equipment and typically facilitating the wearing of the personal protective equipment on the head of a user or worker. Thus, the impact of the falling object onto the personal protective equipment causes pulling away of the free end portions of the straps. The kinetic energy would normally be transmitted to the user's or worker's head and may cause some impact leading to injuries there. With the shock absorber according to the present disclosure, this energy is being absorbed by the deformation of the deformable element to a greater extent compared to a personal protective equipment without the shock absorber assembly according to the present disclosure. Such an absorption includes a partial reduction as well as an entire absorption of the energy upon deformation of the deformable element. In other words, the impact to the user's head is reduced or attenuated, i. e. the impact time is being extended. It is noted that the straps, in particular the middle portions move relative to the deformable element upon deformation of the deformable element. That is, the strap moves in a sliding manner in the direction of the main extension of the strap. The advantage of such a shock absorber assembly is that a space-saving solution for shock absorption is provided. Also, the shock absorption function can easily be integrated into a headgear of a personal protective equipment, for example a protective helmet, a welding shield, a face shield or a respiratory device.
Personal protective equipment (PPE) within the meaning of the present disclosure is understood as articles 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 hard shell and is wom 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 hard 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.
“Deformation” within the meaning of the present disclosure is understood as an action or a process of deforming or distortion resulting in a change in size or shape of an object. According to this disclosure, an object is in a non-deformed condition prior to the deformation, i. e. not showing a change in size or shape, whereas a deformed condition refers to an object being deformed, i. e. having a changed size and/or shape. Such change may apply to the object as a whole or just to parts of the object. Kinetic energy introduced to the deformable element by the straps of the personal protective equipment, e. g. a protective helmet, onto which an object is falling, may introduce forces—through the hard shell and the straps connected thereto—to the deformable element causing its deformation. Upon deformation, kinetic energy is being absorbed by the change of the object's size and/or shape such that the applying energy is reduced or eliminated and does not provide negative impacts to the user's or worker's head anymore. Deformation typically includes elastic or plastic deformation. Elastic deformation is substantially reversible and the deformed element substantially returns after the deformation to its original size and shape prior to deformation. Such a deformation is also referred to as temporary or non-permanent deformation. An elastic deformation may be achieved through the use of a resilient material. In contrast thereto, plastic deformation means that the deformation is irreversible and that the deformed element does not return after the deformation to its original size and/or shape prior to deformation. The plastic deformation is also referred to as permanent deformation. A plastic deformation may be achieved through the use of a brittle material. It is noted that even in case of an elastic deformation, some plastic deformation may occur in parallel or vice versa.
“Mechanical resistance against deformation” within the meaning of the present disclosure is understood as a behavior that an object or element, here a part of the personal protective equipment, exhibits under influence of mechanical forces, i. e. forces acting upon the object or element e. g. when a deformation occurs. In particular, the object or element has the behavior to withstand the mechanical forces to some extent. An absorption of the impacting energy happens partially or entirely.
“Supported” within the meaning of the present disclosure means that the strap is laid onto the surface of the deformable element and is moveable or slidable relative to the surface of the deformable element. Supported does not include a fixed connection between the strap and the deformable element.
“Movable” or “slidable” within the meaning of the present disclosure means that a point on the strap is displaced relative to a point on the surface of the deformable element. In particular, the strap moves or slides in a direction of the main extension of the strap.
“Wrapped tightly” within the meaning of the present disclosure means that the middle portion of the strap is arranged around the deformable element such that no loose or hanging portions or hanging or sagging loops of the straps are created. In other words, the strap is in intimate contact to the surface of the deformable element.
“Shock” within the meaning of the present disclosure is understood as an impact introduced in a short period of time. “Shock absorption” is understood as a delay of that time period leading to an attenuation of the impact.
In a second aspect, the present disclosure relates to a deformable element for a shock absorber assembly for a personal protective equipment. The deformable element exhibits a mechanical resistance against deformation, wherein the deformable element is configured and arranged to support a middle portion of a strap of a personal protective equipment such that—when the strap is tightly wrapped around the deformable element—pulling the end portions of the strap away from each other deforms the deformable element. The deformable element can preferably be brought from a non-deformed condition with the length l, the thickness t, the width w and the support distances d1, d2, d3 to a deformed condition with the length l′, the thickness T′, the width w′ and the support distances d1′, d2′, d3′, such that the length l′ is smaller than length l, the width w′ is smaller than the width w, the support distance d1′ is smaller than the support distance d1, the support distance d2′ is smaller than the support distance d2 and/or the support distance d3′ is smaller than the support distance d3. The advantage of such a shock absorber assembly is that a space-saving solution for shock absorption is provided. Also, the shock absorption function can easily be integrated into a headgear of a personal protective equipment, for example a protective helmet, a welding shield, a face shield or a respiratory device.
In a third aspect, the present disclosure relates to a protective helmet, a welding helmet, a face shield or a respiratory device comprising a hard shell and a shock absorber assembly according to the present disclosure, wherein the hard shell of the protective helmet comprises attachment means for connecting the strap of the shock absorber to the hard shell. The advantage of a protective helmet, a welding helmet, a face shield or a respiratory device with such a shock absorber assembly is that a space-saving solution for shock absorption is provided. Other advantages are listed above for the shock absorber assembly.
In a fourth aspect, the present disclosure relates to a method of retrofitting a shock absorber assembly according to the present disclosure to a personal protective equipment, preferably a protective helmet. The method comprises the steps of: providing a personal protective equipment, preferably a protective helmet, comprising a strap assembly, preferably a headgear; providing a shock absorber assembly according to the present disclosure; removing the strap assembly from the personal protective equipment and mounting the shock absorber assembly on the personal protective equipment. Such a method of retrofitting is beneficial as a standard personal protective equipment, for example a protective helmet, a welding helmet, a face shield or a respiratory device, can easily and reliably be equipped with a shock absorber function, which was not present in that personal protective equipment beforehand. An increase of safety for the user of the personal protective equipment may be achieved thereby. Other advantages are listed above for the shock absorber assembly.
In one embodiment, the deformable element of the shock absorber assembly exhibits an elongated shape having a length l, a width w perpendicular to the length l, a thickness t perpendicular to the length l and the width w and support distances d1, d2, d3 arranged on the deformable element for supporting the strap. The deformable element of the shock absorber assembly can be brought from a non-deformed condition with the length l, the thickness t, the width w and the support distances d1, d2, d3 to a deformed condition with the length l′, the thickness t′, the width w′ and the support distances d1′, d2′, d3′, such that the length l′ is smaller than length l, the width w′ is smaller than the width w, the distance d1′ is smaller than the distance d1, the distance d2′ is smaller than the distance d2 and/or the distance d3′ is smaller than the distance d3. Such an arrangement is beneficial as the change of the dimensions length, width or the support distances may provide for a sufficient and controlled deformation and thus of a sufficient and controlled extension of the free end portions of the strap. Other advantages are listed above for the shock absorber assembly. The length of such a deformable element is greater than the width, for example the length may be 2-times, 3-times or 4-times of the width. Such an elongated shape is beneficial as it provides for an efficient use of the space available in a personal protective equipment, for example a protective helmet, a welding shield, a face shield or a respiratory device. Also, due to the elongated shape, sufficient space is provided on the deformable element such that the strap can reliably be wrapped around in a tight manner and with more than one winding.
In a further embodiment, the deformable element of the shock absorber assembly comprises a main body and an opening formed therein, wherein the main body and/or the opening are deformed upon deformation of the deformable element. The arrangement of an opening formed within the main body of the deformable element provides for a reliable and sufficient deformation of the deformable element when pulling the free end portions away from each other. The opening may undergo a reduction of size and/or an alteration of shape which facilitates a sufficient deformation of the deformable element.
In one embodiment, the length l of the deformable element of the shock absorber assembly decreases upon deformation of the deformable element. Such a deformable element is beneficial as it provides for a reliable and sufficient deformation of the deformable element when pulling the free end portions away from each other.
In a further embodiment, the width w of the deformable element of the shock absorber assembly decreases upon deformation of the deformable element. Such a deformable element is beneficial as it provides for a reliable and sufficient deformation of the deformable element when pulling the free end portions away from each other.
In a further embodiment, the thickness t of the deformable element of the shock absorber assembly decreases upon deformation of the deformable element. Such a deformable element is beneficial as it provides for a reliable and sufficient deformation of the deformable element when pulling the free end portions away from each other.
In yet a further embodiment, at least one of the support distances d1, d2, d3 of the deformable element of the shock absorber assembly decreases upon deformation of the deformable element. Such a deformable element is beneficial as it provides for a reliable and sufficient deformation of the deformable element when pulling the free end portions away from each other.
It is conceivable that the deformable element is configured and arranged such that one, several or all the dimensions, for example the length l, the width w and/or the support distances d1, d2, d3 decrease upon deformation. Such a deformable element is beneficial as it provides for a reliable and sufficient deformation of the deformable element when pulling the free end portions away from each other.
In one embodiment, the middle portion of the strap is supported by the deformable element of the shock absorber assembly. Such an arrangement is of advantage as the strap is reliably and securely arranged at the deformable element thereby.
In another embodiment, the two free end portions of the strap each protrude from the deformable element of the shock absorber assembly. Such an arrangement provides for some design variations within the personal protective equipment, e. g. a protective helmet, as the protruding portions provide for a good fit of the personal protective equipment with such a shock absorber assembly onto the user's or worker's head.
In a further embodiment, the strap of the shock absorber assembly exhibits a tensile strength of 1200 to 1800 N. Such a tensile strength of the strap provides for a reliable and secure personal protective equipment.
In another embodiment, the strap and the deformable element of the shock absorber assembly form a head gear. Such an assembly is of advantage as the shock absorber assembly can replace the head gear of a personal protective equipment, for example a protective helmet, a welding helmet, a face shield or a respiratory device, and provide for a shock absorber function of such a personal protective equipment originally not having that function. In other words, such a head gear with a shock absorber according to the present disclosure can easily be retrofitted to an existing personal protective equipment, for example of the type as mentioned above as the original head gear can be removed and be replaced by such a head gear according to the present disclosure at once or as a whole. In one embodiment, the deformable element of the shock absorber assembly comprises strap guiding means for guiding the strap at the deformable element, wherein the strap guiding means preferably comprises a guiding arm arranged such that a slot for receiving the strap is formed between the guiding arm and the main body of the deformable element. Such a guiding arm and such a slot may be formed such that the slot is open on one end thereof. It is also conceivable that the slot is closed on both ends. The guiding arm may protrude from the perimeter of the deformable element or may protrude from the major surface of the deformable element. A strap guiding means is of advantage as guiding of the strap on the deformable element provides for a reliable and secure assembly. An unwanted movement of the strap, for example in a direction transverse to the main extension of the strap, is prevented thereby while still allowing for movement in the main extension direction of the strap, which is required for the function of the shock absorber assembly.
In another embodiment, the strap of the shock absorber assembly is made of a woven textile. Such a structure has the advantage that the strap exhibits the required properties with regard to tensile strength, flexibility and manufacturing costs.
In another embodiment, the strap of the shock absorber assembly comprises polypropylene, polyester or polyamide. Such a material has the advantage that the strap exhibits the required properties with regard to tensile strength, flexibility and manufacturing costs.
In yet another embodiment, the strap of the shock absorber assembly comprises a twisted portion when wrapped around the deformable element such that the strap exhibits a 180 degrees twist at the deformable element, wherein the strap preferably comprises two twisted portions. As a result of the twisted portion, the strap turns from a first major surface of the deformable element to a second major surface of the deformable element. Such an arrangement with a twisted portion provides for a strap which has a sufficient length of the middle portion wrapped around the deformable element. A sufficient increase of the length of the free end portions of the strap protruding from the deformable element is achieved thereby as more than one layer of the strap on the deformable element can move.
In still another embodiment, the shock absorber assembly comprises two flexible straps each comprising a middle portion and two free end portions facing away from each other. The middle portion is tightly wrapped around the deformable element such that pulling the free end portions away from each other deforms the deformable element. The middle portions of the two straps at least partially overlap with each other. The advantage of such an assembly with two straps is that a good fit of the personal protective equipment is provided when worn by a user.
In one embodiment, the deformable element of the shock absorber assembly comprises a resilient material and wherein the deformation of the deformable element is reversible. Such a resilient material for the deformable element is beneficial as the deformable element may return to its original shape after release of the load, which may provide for a re-usable shock absorber assembly.
In a certain embodiment, the resilient material of the deformable element of the shock absorber assembly is selected from polycarbonate, polyethylene, preferably high-density polyethylene, acrylonitrile-butadiene-styrene. Such a material is advantageous because it provides for reliable properties of the deformable element regarding the deformation and the return to the original shape.
In one embodiment, the deformable element of the shock absorber assembly comprises a brittle material and wherein the deformation of the deformable element is irreversible. Such a brittle material facilitates an irreversible deformation of the deformable element. This may be useful to provide an indicator function to the user of the personal protective equipment, i. e. an indication to the user that the deformable element has been deformed. Also, an unwanted re-use of the shock absorber assembly may be prevented thereby.
In a certain embodiment, the brittle material of the deformable element of the shock absorber assembly is selected from polystyrene, polyvinyl chloride, acrylic materials. Such a material is advantageous because it provides for reliable properties of the deformable element regarding deformation and further supports the indication function to the user about a load acting on the strap.
In another embodiment, the thickness t of the deformable element of the shock absorber assembly is in the range of 0.1 to 5 mm in a non-deformed condition. Such a thickness is of advantage as it provides for a space-saving arrangement of the deformable element within a personal protective equipment, for example a protective helmet, on the one hand and for a reliable and stable design of the deformable element on the other hand.
In one embodiment, the shock absorber assembly comprises an indicator for indicating a deformation of the deformable element. Such an indicator is of advantage as it provides for a reliable indication—independent of the optical appearance of the deformable element—of a deformation of the deformable element which has happened upon acting of a load on the personal protective equipment. In other words, even if the deformation of the deformable element is not visible to the user (any longer), e. g. a deformable element which is elastically deformable and the deformation of the deformable element is reversible, respectively, there is an indication to the user of a deformation that has happened. In some countries, personal protective equipment may underlie regulatory aspects and such a regulation may require that there is a reliable indication about a shock absorber that has been activated.
In a certain embodiment, the indicator of the shock absorber assembly has a load threshold value for the load impact and wherein the indicator indicates the load impacting onto the deformable element above the load threshold, wherein the load threshold value is preferably between 500 N and 10 kN. It is noted that there may specific values be set for specific personal protective equipment depending on demand in the geographic area. Such a load threshold value is of advantage as the indicator does not indicate low impacts, i. e. impacts of a low load which may be considered uncritical. An indication provided by such an indicator means that the load was reasonably high and therefore it is important that the user is being informed about that.
In certain embodiments, the indication of the indicator of the shock absorber assembly is irreversible. Tat means that the indicator undergoes a shape, size and/or appearance change which irreversibly indicates a deformation of the deformable element of the shock absorber assembly to which the indicator belongs or to which the indicator is attached to. Such an indicator is beneficial as the indication is permanently observable even if the deformable element is elastically deformable and returns to its shape and appearance after the load impact. Such an irreversible indicator may comprise an ink or a paint arranged on the surface of the deformable element, wherein the ink or paint exhibits optical defects after a load impact, e. g. cracks. It is also conceivable that the indicator comprises a mechanical indicator element, e. g. a thread or other thin structure which ruptures when a load impacted on the shock absorber.
In certain embodiments, the indicator of the shock absorber assembly is attachable to the deformable element. Such an attachable indicator has the advantage that it can be replaced after indication and the deformable element is still usable with a new indicator. This is particularly useful if the deformable element is elastically deformable and the deformation is reversible. Also, the indicator may be replaced by another one, i. e. an indicator with different properties, e. g. different sensitivity. The shock absorber assembly and/or the indicator may comprise attachment means for attaching the indicator to the deformable element of the shock absorber assembly. The attachment means may comprise a mechanical attachment means such as mechanical fasteners, snap fit or the like, an adhesive attachment means such as an adhesive layer or a combination thereof. The advantage of such an attachment means is that an easy and reliable way of attaching the indicator to the deformable element of the shock absorber is provided thereby.
In a certain embodiment, the indicator of the shock absorber assembly is integral with the deformable element. For example, the indicator is formed as a protrusion of an edge of the deformable element, which may protrude from the edge into an opening present at the deformable element of the shock absorber assembly. Other arrangements are conceivable as well, for example an indicator arranged on the surface of the deformable element or protruding from an outer edge of the deformable element. Such an integral indicator has the advantage that no attachment means are required. Also, an easy, compact and robust arrangement of the indicator is provided thereby. Furthermore, an unwanted replacement of the indicator is prohibited thereby, which may in particular be required by regulations.
In one embodiment of the method of retrofitting a shock absorber assembly according to the present disclosure to a personal protective equipment, the personal protective equipment is a protective helmet, a welding helmet, a face shield or a respiratory device. Such a method of retrofitting is beneficial as a standard personal protective equipment, for example a protective helmet, a welding helmet, a face shield or a respiratory device, can easily and reliably be equipped with a shock absorber function, which was not present in that personal protective equipment beforehand. In particular, retrofitting the shock absorber assembly to a protective helmet, a welding shield, a face shield or a respiratory device provides an increased level of safety for such personal protective equipment.
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:
Due to the releasable attachment means 130, the shock absorber assembly 10 may have been retrofitted to the protective helmet 100 by removing the initial assembly, e. g. a standard head gear without shock absorption, by disconnecting its attachment means from the attachment means 130 of the protective helmet 100 and replacing the initial assembly with the shock absorber assembly 10 according to the present disclosure by connecting the attachment means 120 with the corresponding attachment means 130 of the protective helmet 100. It is also conceivable that the connection between the attachment means 120 of the shock absorber assembly 10 and the attachment means 130 of the protective helmet 100 is permanent, i. e. not releasable or disconnectable.
Number | Date | Country | Kind |
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21216403.2 | Dec 2021 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2022/062534 | 12/20/2022 | WO |