Field of the Invention

[01] The present invention generally relates to a self-adjusting head basket for a helmet, as well as to a helmet including said self-adjusting head basket.

Background of the Invention

[02] A helmet is commonly worn to protect the head of a wearer from impact related injury, especially while practicing a variety of sports where the athlete is prone to endure such impacts to the head, for example skateboarding, skiing, biking, snowboarding, water sports, mountain biking, and horseback riding. Such helmets generally comprise a fastening system to keep the helmet securely on the head of the wearer in case of an accident. A fastening system can generally comprise two straps, attached to opposite lateral sides of the helmet. The straps may be connected by means of a buckle underneath the chin of the wearer to secure the helmet on the wearer’s head.

[03] However, the fastening system may not prevent the helmet from rocking back and forth while worn, especially during dynamic activities such as the aforementioned sports, and/or when the helmet does not perfectly fit a wearer’s head. To address this problem, a retention system may be added to further secure the helmet to a wearer’s head by providing an adjustable fit along a circumference of the wearer’s head. Several manual retention systems are known. They may require manual actions to adjust their fit. These systems often comprise a head basket, one or more tensioning cables, and an adjustment mechanism. A size of the head basket which at least partially encloses the wearer’s head, can be adjusted by tightening or loosening the tensioning cables. The adjustment mechanism, often located at the rear of the head, commonly comprises a ratcheting mechanism that engages the tensioning cables. The adjustment system may further be operated by turning a wheel or knob, thereby tightening or loosening the tensioning cables, to adjust the fit of the retention system. [04] The plurality of components of known retention systems can make a conventional manual retention system rather complex, both in operation and in manufacturing. As such, these systems may require one or more manual actions from the wearer to adjust the fit, such as for example the turning of a knob, and are expensive to produce. Additionally, it may be a challenge to tighten the manual retention system such that it provides a secure fit while still being comfortable for the wearer, especially when tightening of the helmet is not performed by the wearer himself/herself, for example when a parent tightens the helmet of a child.

[05] An automatic retention system is a known alternative that partially addresses the aforementioned challenges of manual retention systems. While they may comprise similar components to manual retention systems, such as a head basket and tension cables, they may require fewer manual actions from the wearer to adjust the fit. This is because in automatic retention systems, a tensioning means automatically tightens the retention system along the wearer’s head, replacing the function of the adjustment mechanism in manual retention systems. The tensioning means may for example include a pre-tensioned element, such as for example a spring or an elastic band.

[06] As an example, US 2004/0255370 A1 discloses a fit element for a helmet including a base portion and a stretchable material which is integrated with at least a section of the base portion for contact with the wearer’s head.

[07] However, these automatic retention systems can still comprise several components that have to be operatively connected to one another and/or to the helmet. These components may further be made of different materials. As such, manufacturing and assembling can remain relatively complex and labour-intensive, which negatively affects the cost.

Summary of the Invention

[08] It is an object of the present invention, amongst others, to at least partly solve the above identified challenges and problems. In particular, it is an object of the invention to provide a comfortable self-adjusting head basket that allows relatively easy manufacturing, assembling, and operation.

[09] According to a first aspect of the invention, this object is achieved by a self- adjusting head basket for a helmet as claimed in claim 1. The self-adjusting head basket is attachable to an internal surface of the helmet. The head basket is configured to enclose at least part of the wearer’s head. The head basket comprises at least one tensioning means, configured to automatically tension the head basket along a wearer’s head. The at least one tensioning means comprises a wirelike element including at least one meandering portion partly delimiting at least one void. As such, the at least one tensioning means is extendable from an equilibrium position, in which the at least one tensioning means has a predetermined length, to a tensioned position, in which the at least one tensioning means has an elongated length relative to the predetermined length.

[10] In the context of the present application, the at least one meandering portion refers to any shape of zigzagging or meandering portion including at least one back and forth portion. In other words, the wirelike element includes a kind of bend such that the wirelike element substantially returns to a starting side while partly delimiting a void. The at least one void is to be understood as defined in a dictionary: as an empty space. The at least one void does not include any material and is thus a portion free of material, an empty portion. The wirelike element may, but need not have a substantially round cross-section, the element may also have any other cross-sectional shape, as long as its overall shape is longitudinal and substantially slender like a wire or a thread or a band.

[11] Such a meandering portion of a wirelike element partly delimiting a void allows local flexing and extension of the tensioning means, thereby changing an opening length of the at least one void. The opening length of the void can be measured along a longitudinal direction of the tensioning means. The opening of the void is where the void is not delimited by the wirelike element and is generally located along a longitudinal edge of the tensioning means. The at least one void, in particular the opening of the at least one void, may be relatively small, such that the at least one void can be reduced to a slit. In some cases, the at least one void may also be fully delimited by the wirelike element, without having an opening along the longitudinal edge of the tensioning means. When the tensioning means is undisturbed, e.g. when the head basket is not in use, it is said to be in a first equilibrium position in which the tensioning means has a predetermined length. The self-adjusting head basket can receive a wearer’s head by extending the at least one tensioning means to a second tensioned position, in which the tensioning means has an elongated length relative to the predetermined length, the elongation of the tensioning means being made possible thanks to the wirelike element including at least one meandering portion partly delimiting at least one void. In particular, a path of the wirelike element, in particular of the meandering portion, may be slightly stretched out thanks to the void delimited by the meandering portion.

[12] The at least one tensioning means in the tensioned position is subject to a restoring force, configured to restore the at least one tensioning means to the equilibrium position. Thanks to this restoring force alone, the head basket can be tensioned automatically along the wearer’s head, thereby securing the head basket. There is no need for any further tensioning means of different types. It is therefore an advantage of the present invention that the complexity of the head basket can be reduced, as it includes a relatively simple adjustment mechanism. It is a further advantage that the head basket can be correctly tightened without manual adjustments of the wearer. It is another advantage that the head basket can be correctly tightened when equipping another person with a helmet including said head basket, such as for example a child.

[13] The wirelike element of the at least one tensioning means may further include a plurality of meandering portions partly delimiting a plurality of voids, such that the wirelike element of the at least one tensioning means includes a geometric pattern. Thanks to a plurality of meandering portions and voids, in particular thanks to an arrangement of said plurality of meandering portions and voids, in the at least one tensioning means, the remaining material, i.e. the wirelike element, may form a geometric pattern. The voids can for example be oriented into alternating directions, for example an alternation of upwardly and downwardly oriented voids, or an alternation of left-sided and right-sided laterally oriented voids depending on the viewpoint. The self-adjusting head basket may easily be adapted by adjusting or choosing a specific geometric pattern, i.e. by adjusting an arrangement and/or shape of the meandering portions and voids. Thanks to a choice of the geometric pattern, the self-adjusting head basket may for example be adapted to, amongst others, the accepted head size by the self-adjusting head basket, the required magnitude of the restoring force, the desired progressiveness of the restoring force, and/or the flexibility of the tensioning means.

[14] Preferably, the geometric pattern may further include a wavy pattern. In particular, the plurality of meandering portions and voids may be arranged such that the wirelike element of the at least one tensioning means forms a wavy pattern. A wavy pattern is to be understood as a smooth pattern, free of sudden breaks and/or sudden changes in direction, i.e. free of corners, angles or sharp edges. This has the advantage that the at least one tensioning means is relatively strong and resilient to repeated elongation and contraction, as corners are generally a relatively weak point where mechanical fatigue may accumulate. Alternatively, angled geometric patterns may be used as well, or a combination of angled and wavy patterns. The wavy pattern may be a substantially symmetric pattern along a longitudinal axis of the tensioning means and/or along an axis transverse to the longitudinal direction of the tensioning means, or may be a substantially asymmetric pattern.

[15] The self-adjusting head basket may further be made of a single material. In other words, all the components of the self-adjusting head basket may be made of a substantially equal or same material, i.e. the material of the at least one tensioning means may be substantially equal to the material of the rest of the head basket. It is to be understood that a single material may include materials produced from two or more constituent materials of dissimilar chemical or physical properties, such as for example composite materials. It is an advantage that this facilitates manufacturing, as all components can be made by the same process, in particular, in a single process.

[16] The self-adjusting head basket may include a plurality of tensioning means, wherein each of said plurality of tensioning means is configured to automatically tension the head basket along a wearer’s head and wherein each of said plurality of tensioning means comprises a wirelike element including at least one meandering portion partly delimiting at least one void. In other words, each of the plurality of tensioning means is a tensioning means of substantially the same type providing a restoring force solely based on the shape of the tensioning means, in particular on said wirelike element including at least one meandering portion partly delimiting at least one void. There is no need for any combination with a tensioning means of a different type, such as a tensioning means including a stretchable or flexible or elastic material of which the restoring force is based on the material, in particular on the elastic, properties of the material rather than on the shape. In this way, the manufacturing of the self- adjusting head basket may be simplified.

[17] Preferably, the self-adjusting head basket may further be a single piece. In other words, all the components of the self-adjusting head basket may form an unbroken whole, i.e. the at least one tensioning means may be inseparable from the head basket. More preferably, the self-adjusting head basket may further be a single moulded piece, i.e. manufactured by means of a moulding process such as for example injection moulding or compression moulding. It is an advantage that this can further facilitate manufacturing, as all components can be made by a single process without requiring further assembling.

[18] The head basket may further comprise at least one aeration opening. One or more openings may be included in the head basket to provide fresh air and to expel perspiration, i.e. provide ventilation to the wearer’s head. Such an aeration opening can provide a relatively comfortable head basket, especially during strenuous activity when perspiration may accumulate between the wearer’s head and the head basket. It is a further advantage that the head basket is made of a relatively limited amount of material, reducing cost and weight.

[19] A central portion of a lower periphery of the head basket may further comprise an indent, relative to opposite lateral sides of said central portion of said lower periphery, the indent being configured to allow passage of tied hair of the wearer. In other words, the lower outer limit of the head basket may comprise an indent substantially in a middle portion of said head basket, i.e. which portion is configured to cover substantially the middle of the back of the wearer’s head. The wording ‘lower’ refers to a position of the periphery or perimeter of the head basket when worn by a wearer, which is lowest at a back of a wearer’s head. The indent may extend substantially towards a middle of the head basket, to provide sufficient space for tied back hair to freely be passed. A middle of the head basket is usually configured to cover a crown of the wearer’s head. This has the advantage that the head basket is more comfortable when the wearer’s hair is tied back, for example in a ponytail.

[20] The self-adjusting head basket may further comprise at least one lateral leg, configured to at least partially enclose a lateral side of the wearer’s head. In other words, the at least one lateral leg may extend from the head basket and be configured to extend along the lateral side of the wearer’s head towards the front. Preferably, the at least one lateral leg may further comprise the at least one tensioning means. As such, the at least one tensioning means may be located at a lateral side of the wearer’s head. More preferably, the at least one lateral leg may further comprise at least one attachment element, configured to attach the at least one lateral leg to the helmet. In other words, the at least one lateral leg may be attached to the helmet, for example at an end of the at least one lateral leg and at a distance of the head basket. Attachment to the helmet may for example be done to a lateral and/or frontal inner side of the helmet.

[21] The self-adjusting head basket may further comprise at least one superior leg, configured to at least partially enclose a superior side of the wearer’s head. In other words, the at least one superior leg may extend from the head basket and be configured to extend along the back side and the superior side of the wearer’s head, i.e. the crown of the wearer’s head. Preferably, the at least one superior leg further can comprise at least one attachment element, configured to attach the at least one superior leg to the helmet. In other words, the at least one superior leg, for example an end of said at least one superior leg, may be attached to the helmet. Attachment to the helmet may for example be done to a superior and/or frontal inner side of the helmet.

[22] According to a second aspect, the invention relates to a helmet comprising the self-adjusting head basket as claimed in claim 13. Such a helmet can provide one or more of the above-mentioned advantages.

Brief Description of the Drawings [23] Fig. 1 shows a perspective view on a preferred embodiment of a self-adjusting head basket for a helmet according to a first aspect of the invention;

[24] Fig. 2A and Fig. 2B show a side view and a top view respectively on the preferred embodiment of Fig. 1 in a tensioned position relative to an equilibrium position;

[25] Fig. 3A and 3B show a schematic side view on a tensioning means in an equilibrium position and a tensioned position respectively of the self-adjusting head basket of Fig. 1 ;

[26] Fig. 4 shows a schematic side view on an alternative embodiment of a tensioning means for a self-adjusting head basket according to a first aspect of the invention; and

[27] Fig. 5 shows a schematic side view on further alternative embodiments of a tensioning means for a self-adjusting head basket according to a first aspect of the invention.

Detailed Description of Embodiment(s)

[28] Fig. 1 shows a perspective view on a preferred embodiment of a self-adjusting head basket 100 for securing a helmet to a wearer’s head by providing an adjustable fit along the circumference of a wearer’s head. The circumference of a wearer's head refers to the largest circumference measured above the eyebrows, above the ears, and around the back of the head. The head basket 100 can prevent the helmet from rocking back and forth while worn, especially during dynamic activities where the wearer is prone to endure impacts to the head, e.g. skateboarding, skiing, biking, snowboarding, water sports, mountain biking, and horseback riding. By preventing rocking of the helmet, the self-adjusting head basket 100 may provide a relatively comfortable fit of the helmet on a wearer’s head and may thus aid in protecting the head of a wearer relatively well against impact related injury. The self-adjusting head basket 100 is configured to at least partially enclose a wearer’s head. Preferably, the self-adjusting head basket 100 may at least partially enclose the back of a wearer’s head. The self-adjusting head basket 100 includes at least one tensioning means 120 configured to automatically tension the head basket 100 along the wearer’s head, thereby requiring relatively limited manual actions by the wearer to adjust the fit.

[29] The head basket 100 may further include at least one, and preferably a plurality of, aeration openings 111, 112, 113 to provide fresh air and to expel perspiration, i.e. provide ventilation to the wearer’s head. Such an aeration opening 111, 112, 113 can provide a relatively comfortable head basket 100, especially during strenuous activity when perspiration may accumulate between the wearer’s head and the head basket 100. By including said aeration openings, the head basket 100 may further be made of a relatively limited amount of material, reducing cost and weight. The aeration openings 111, 112, 113 may further vary in shape, size, and arrangement according to the desired level of ventilation, weight savings, or production costs.

[30] The lower outer limit of head basket 100, i.e. the lower periphery 115, may comprise an indent in a substantially middle portion of said head basket 100, i.e. a portion that is configured to cover substantially the middle of the back of the wearer’s head. The wording ‘lower’ refers to a position of the periphery or perimeter of the head basket 100 when worn by a wearer, which is lowest at the back of a wearer’s head. The indent may extend substantially towards a middle of the head basket, or may extend upwardly when the head basket is worn by a user, to provide sufficient space for tied back hair to freely be passed. A middle of the head basket 100 may be configured to cover the crown of the wearer’s head. Preferably, the indent is located in a central portion of the head basket 100 relative to opposite lateral sides of said central portion of the lower periphery 115. This may result in a head basket 100 that is more comfortable when the wearer’s hair is tied back, for example in a ponytail.

[31] The self-adjusting head basket 100 may further comprise at least one lateral leg 130, preferably two lateral legs 130, configured to at least partially enclose a lateral side of the wearer’s head. In other words, the lateral legs 130 may be configured to extend along the lateral side of the wearer’s head towards the front. Preferably, the self-adjusting head basket 100 may comprise two lateral legs 130, each partially enclosing an opposing lateral side of the wearer’s head, for example just above an ear region, and extending from the back of the wearer’s head towards the front. Alternatively, two lateral legs 130 may join and form a single band configured to extend over a front side of a user’s head.

[32] The at least one lateral leg 130 can advantageously comprise the at least one tensioning means 120. As such, the at least one tensioning means 120 may be located along a lateral side of the wearer’s head. More preferably, each of said respective legs 130 includes a tensioning means 120 such that the self-adjusting head basket 100 comprises two tensioning means 120, located at each respective lateral side of the wearer’s head. Alternatively, and/or additionally, a tensioning means 120 may be located elsewhere in the head basket 100, for example at the back or the front of the wearer’s head.

[33] Preferably, each lateral leg 130 may further include at least one attachment element 135, 136, configured to attach the at least one lateral leg 130 to the helmet. The lateral legs 130 may be attached to the helmet for example towards an end of the at least one lateral leg or at any other place along the lateral leg 130. Attachment to the helmet may for example be done to a lateral or frontal inner side of the helmet. The attachment elements 135, 136 may for example be, amongst others, retainers, screws, bolts, rivets, grommets, plugs, pins, snap fasteners, or snap fits or any other attachment elements known to the person skilled in the art. The helmet, in particular an inner side of the helmet, may comprise corresponding elements configured to receive the attachment elements 135, 136. The attachment elements 135, 136 may further provide a releasable or permanent connection to the helmet.

[34] The self-adjusting head basket 100 may further comprise at least one superior leg 140, which may extend from the head basket 100 towards a superior side of the wearer's head when in use along the back side and the superior side of the wearer’s head, i.e. the crown of the wearer’s head. As such, the superior leg 140 may at least partially enclose a superior side of the wearer’s head when in use. Preferably, the superior leg 140 can further comprise at least one attachment element 141, 142, configured to attach the superior leg 140 to the helmet. The superior leg 140, for example an end of said superior leg 140, may be attached to the helmet. Attachment to the helmet may for example be done to a superior or frontal inner side of the helmet. The attachment elements 141, 142 may for example be, amongst others, retainers, screws, bolts, rivets, grommets, plugs, pins, snap fasteners, or snap fits or any other attachment elements known to the person skilled in the art. The helmet, in particular an upper inner side of the helmet, may comprise corresponding elements configured to receive the attachment elements 141, 142. The attachment elements 141, 142 may further provide a releasable or permanent connection to the helmet.

[35] The self-adjusting head basket 100 may advantageously be made of a single material. In other words, all the components of the self-adjusting head basket 100 including the tensioning means 120, the lateral legs 130 and the superior leg 140 may be made of a substantially equal or same material. This facilitates manufacturing, as all components can be made by the same process, in particular, in a single process. It is to be understood that a single material may include materials produced from two or more constituent materials of dissimilar chemical or physical properties, such as for example composite materials.

[36] The self-adjusting head basket 100 may preferably be a single piece, and more preferably be made of a single material. In other words, all the components of the self- adjusting head basket 100 may form an unbroken whole, i.e. the tensioning means 120, the lateral legs 130, and the superior leg 140 may be inseparable from the head basket 100. This can further facilitate manufacturing, as all components can be made by a single process without requiring further assembling, such as for example injection moulding, rotational moulding, extrusion, blow moulding, reaction injection moulding, compression moulding, CNC machining, or 3D printing. Preferably, the self-adjusting head basket 100 may be a single moulded piece, i.e. manufactured by means of a moulding process such as for example injection moulding or compression moulding.

[37] Fig. 2A and Fig. 2B respectively show a side view 200 and a top view 210 on a self-adjusting head basket 100 comprising at least one tensioning means, preferably two tensioning means 120. The tensioning means 120 is extendable from a predetermined length in an equilibrium position 201 , 211 , in grey in the Figures 2A and 2B, to an elongated length in a tensioned position 202, 212, in black in the Figures 2A and 2B, by exerting an extension force 220 on the head basket. As such, the partial circumference of the head basket 100 measured from the one of the lateral legs 130 over the hind middle portion to the other lateral leg 130 can be increased. Such an extension of the tensioning means 120 may for example occur when a user wants to put the head basket 100 or a helmet including said head basket 100 over his/her head. The self-adjusting head basket 100 can thus receive a wearer’s head by extending the tensioning means to a tensioned position 202, 212, in which the tensioning means have an elongated length relative to the predetermined length in the equilibrium position 201 , 211. Preferably, the tensioning means 120 can be extended with relative ease by exerting the extension force 220 on the head basket, e.g. by one or more fingers, by hand, or by inserting the wearer's head in the head basket.

[38] The tensioning means 120 in the tensioned position 202, 212 may further be subject to a restoring force 230, which tends to restore the tensioning means 120 to the equilibrium position 201, 211 and thereby tends to bring the head basket 100 back from the tensioned position 202, 212 to the equilibrium position 201, 211. The predetermined length of the tensioning means in the equilibrium position 201, 211 is preferably chosen such that the combined circumference of the head basket 100 measured from the one of the lateral legs 130 over the hind middle portion to the other lateral leg 130 and a partial circumference measured along an internal front portion of a helmet including said head basket 100 is smaller in the equilibrium position 201 , 211 than a circumference of a user's head. As such, the restoring force 230 generated by the tensioning means 120 in the tensioned position can automatically tension the head basket along a user's head when said head is inserted into a helmet including said head basket, without requiring substantial manual adjustments. To allow said extension of the tensioning means 120 and generate the restoring force 230, each of the tensioning means comprises a wirelike element 122 including at least one meandering portion partly delimiting at least one void 121. Said void 121 is an empty space, i.e. free of any material, as shown in all of the figures.

[39] Fig. 3A and 3B show a schematic side view of the tensioning means 120 of self- adjusting head basket 100, including a wirelike element 122. The wirelike element 122 is arranged such that it includes a plurality of meandering portions partly delimiting voids 302, such that the wirelike element 122 of the tensioning means forms a geometric pattern. The plurality of voids 302 may be located along a longitudinal edge of the tensioning means in an alternating manner. In the equilibrium position 300, the tensioning means may be substantially undisturbed having a predetermined length 301 , for example from about 5 mm to about 150 mm, preferably from about 10 mm to about 75 mm, more preferably around 55 mm, and the plurality of voids 302 may have an equilibrium opening length 303, for example from about 1 mm to about 100 mm, preferably from around 1 mm to about 10 mm, more preferably more or less 2 mm. A tensioning means may be in said equilibrium position 300 in absence of a force working on the head basket 100, i.e. the extension force 220, e.g. when the head basket is not on a wearer's head. In the tensioned position 310, the tensioning means may have an elongated length 311, for example from about 15 mm to about 200 mm, more preferably from around 30 mm to around 160 mm, for example more or less 65 mm, and the plurality of voids 312 may have an elongated opening length 313, for example from about 2 mm to about 150 mm, for example more or less 7 mm. In this tensioned position 311 , the tensioning means may further be subject to a restoring force 230, which tends to restore the tensioning means to equilibrium position 300. A length of the wirelike element 122 does not change between the equilibrium position 300 and the tensioned position 310 since the wirelike element 122 is preferably made of a non elastic material, for example of the same material as the head basket 100. Preferably, only the arrangement of the wirelike element can contribute to the elongation of the tensioning means from the predetermined length 301 in the equilibrium position 300 to the elongated length 311 in the tensioned position 310 in that an arrangement or a path of the wirelike element 122 is slightly changed, in particular bending angles of the meandering portions can be widened which is allowed by the voids delimited by the meandering portions. As a consequence, also the opening lengths 303, 313 of the voids 302 are then increased.

[40] Fig. 4 shows a schematic side view of an alternative tensioning means 400 having a wirelike element 415 including a meandering portion 412 which partly delimits at least one void, for example two voids 410, 411. The tensioning means 400 may for example have a substantially rectangular shape extending along a longitudinal direction 401 and having a height measured along direction 402. The tensioning means 400 may further comprise a distal lateral surface 420, i.e. the lateral surface of the tensioning means 400 configured to be facing away from a wearer’s head, and a proximal lateral surface 421, i.e. the lateral surface of the tensioning means 400 configured to be facing the wearer’s head when the head basket 100 is worn by a wearer. The tensioning means 400 may further comprise longitudinal edges 423, 424.

[41] The tensioning means 400 comprises a wirelike element 415 including a meandering portion 412 partly delimiting two voids 410, 411. The at least one meandering portion 412 of the wirelike element 415 refers to any shape of zigzagging or meandering portion including at least one back and forth portion, e.g. between the opposing longitudinal edges 423, 424. In other words, the wirelike element includes a kind of bend such that the wirelike element substantially returns to a starting side while partly delimiting a void 410, 411. A void 410, 411 may be understood as a predetermined portion of the tensioning means 400 that is free of material. Such a void may be relatively small and may even be a slit into the tensioning means 400. An opening of the void 410, 411 may further have a predetermined length along the longitudinal direction 401. The void 410, 411 may further have a predetermined height measured along direction 402. The voids 410, 411 may also be described as an indentation, an incision or a slit in the longitudinal edges 423, 424 of the tensioning means.

[42] The meandering portion 412 of the wirelike element 415 partly delimiting the void 410, 411 then allows local flexing and extension of the tensioning means 400. When an extension force is exerted on the tensioning means 400, an opening length 413, 414 of the at least one void 410, 411 measured along the longitudinal direction 401 of the tensioning means 400 can be changed, in particular increased. The opening of the void 410, 411 is where the void is not delimited by the wirelike element 415 and is generally located along a longitudinal edge 423, 424 of the tensioning means 400. When an extension force is exerted on the tensioning means 400, a path of the meandering portion 412 of the wirelike element 415 can be changed, in particular slightly stretched. In other words, extension of the tensioning means 400 does not substantially stretch the material of the tensioning means 400 but can rather increase a distance the tensioning means 400 can span along the longitudinal direction 401 thanks to an increase of the opening lengths 413, 414 of the voids and the changed arrangement of the meandering portion 412 of the wirelike element 415. The voids 410, 411 can thus enable a substantially rigid material to warp or bend locally and revert back to shape. This can allow the tensioning means 400 to be made of a relatively rigid material, for example substantially similar to the material of the head basket 100.

[43] Fig. 5 shows a schematic side view of alternative embodiments of tensioning means of a self-adjusting head basket 100 having various geometric patterns 510, 520, 530. A specific geometric pattern may be achieved by adjusting the arrangement of the wirelike element, and/or the shape, quantity, and spacing of the meandering portions delimiting the voids 511 , 521 , 522, 523, 531 , 532 in the tensioning means. In this way, the desired properties of the tensioning means may easily be provided by choosing a specific geometric pattern. A self-adjusting head basket 100 may for example be adapted to, amongst others, the accepted head size of the self-adjusting head basket 100, the required magnitude of the restoring force 230, the desired progressiveness of the restoring force 230, the required extension force 220 and the desired flexibility of the tensioning means. The geometric patterns 510, 520, 530 are primarily defined by the arrangement of the wirelike element, in particular by the shape or path of the meandering portions and the shape of the voids 511 , 521 , 522, 523, 531 , 532 partly delimited by said meandering portions of the wirelike element. The voids may for example have the shape of substantially, amongst others, a square, a rectangle, a diamond, a circle, an ellipse, a triangle, a parallelogram, a polygon, a combination thereof, or any other shape known to the person skilled in the art.

[44] For example, geometric pattern 510 shows a wirelike element following a wavy pattern including meandering portions partly delimiting substantially identically shaped voids 511. A wavy pattern is to be understood as a smooth pattern, free of sudden breaks and/or sudden changes in direction, i.e. free of corners, angles or sharp edges. The absence of sharp angles or corners has the advantage that the tensioning means is relatively strong and resilient to repeated elongation and contraction, as corners are generally a relatively weak point where mechanical fatigue may accumulate. Even if the geometric pattern 510 is free of corners, it is less advantageous than the geometric pattern of the tensioning means shown in Figures 3A and 3B since the length of the wirelike element is shorter in 510 than in the Figures 3A and 3B for a same length of the tensioning means. As a consequence, the tensioning means 122 of Figures 3A and 3B can be used for a head basket and a helmet spanning a larger range of head sizes than a tensioning means having the geometric pattern 510. The wavy pattern may be a substantially symmetric pattern along a longitudinal direction of the tensioning means and/or along the width direction, or may be a substantially asymmetric pattern, as is shown in pattern 520. As a consequence of the meandering portions of the wirelike element, these voids 511 partly delimited by the meandering portions are oriented into alternating directions, e.g. an alternation of upwardly and downwardly oriented voids. Alternatively, the tensioning means could be arranged in a head basket such that Figures 3A, 3B, 4 and 5 are top views of the tensioning means instead of side views. In that case, an opening of the voids would be directed alternatingly facing a user’s head and facing away from a user’s head when the head basket is in use.

[45] Alternatively, angled geometric patterns may be used as well, or a combination of angled and wavy patterns. An alternative geometric pattern 520 may be obtained by an arrangement of the wirelike element including meandering portions of various shapes partly delimiting voids 521, 522, 523 of at least two different shapes. These differently shaped voids may be repeated in alternating orientations. The meandering portions need to be such that a substantially straight line can be drawn in the longitudinal direction through the tensioning means which line can cross all of the alternatingly oriented voids partly delimited by the meandering portion of the wirelike element.

[46] A further geometric pattern is referenced as 530 and includes a wirelike element including a plurality of meandering portions delimiting two different types of voids: a first type, for example void 532 is similar to all preceding examples since the void is partly delimited by the wirelike element and partly by a longitudinal edge of the tensioning means. At the same time, the wirelike element delimits substantially central voids or through holes 531. The wirelike element may be considered as including split wirelike arms which join and split in an alternating manner. Said pattern also shows that the wirelike element may have some width or thickness like a band.

[47] Although the present invention has been illustrated by reference to specific embodiments, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied with various changes and modifications without departing from the scope thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. In other words, it is contemplated to cover any and all modifications, variations or equivalents that fall within the scope of the basic underlying principles and whose essential attributes are claimed in this patent application. It will furthermore be understood by the reader of this patent application that the words "comprising" or "comprise" do not exclude other elements or steps, that the words "a" or "an" do not exclude a plurality, and that a single element, such as a computer system, a processor, or another integrated unit may fulfil the functions of several means recited in the claims. Any reference signs in the claims shall not be construed as limiting the respective claims concerned. The terms "first", "second", third", "a", "b", "c", and the like, when used in the description or in the claims are introduced to distinguish between similar elements or steps and are not necessarily describing a sequential or chronological order. Similarly, the terms "top", "bottom", "over", "under", and the like are introduced for descriptive purposes and not necessarily to denote relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and embodiments of the invention are capable of operating according to the present invention in other sequences, or in orientations different from the one(s) described or illustrated above.