Patent Publication Number: US-9883709-B2

Title: Mechanically joined helmet bodies and method for same

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional patent application 62/347,054, filed Jun. 7, 2016 titled “Mechanically Joined Helmet Bodies and Method for Same,” the entirety of the disclosure of which is hereby incorporated by this reference. 
    
    
     TECHNICAL FIELD 
     Aspects of this document relate generally to helmets having mechanically joined helmet bodies and methods for the same. 
     BACKGROUND 
     Helmets function to provide protection while minimizing interference with the performance or enjoyment of an otherwise dangerous activity. The shape of a helmet may be adapted to provide both protection and comfort. For example, a helmet may be shaped to increase ventilation, or to reduce weight and volume. Some helmets are made up of two or more bodies of energy-absorbing material to form shapes that would be difficult, if not impossible, to achieve in a single molded piece. Conventional helmets are made by joining helmet bodies with adhesives, or by in-molding the helmet bodies together. 
     SUMMARY 
     A need exists for an improved helmet comprising mechanical attachment of multiple helmet bodies. Accordingly, in an aspect, a helmet can comprise an upper body comprising an interior surface comprising a locking flange. A lower body can be positioned at least partially inside the upper body, the lower body comprising an edge in contact with the locking flange of the upper body. At least one joining pin can be located within both the lower body and the upper body, bridging the lower body and the upper body. At least one basket pair can comprise an upper basket, a lower basket, and at least one joining pin. The upper basket can comprise a pin receiver, the upper basket being at least partially embedded within the upper body. The lower basket can comprise a pin aperture, the lower basket at least partially embedded within the lower body and positioned such that the pin aperture is aligned with the pin receiver of the basket pair. The at least one joining pin can be positioned inside both the pin aperture and the pin receiver of the basket pair. 
     The helmet can further comprise the locking flange being proximate a front rim of the upper body, and the at least one joining pin being proximate a rear rim of the upper body. The upper basket of the at least one basket pair can be in-molded within the upper body, and the lower basket of the at least one basket pair can be in-molded within the lower body. The at least one joining pin can be releasably coupled to at least one of the pin receiver and the pin aperture of the at least one basket pair. At least a portion of an exterior surface of the lower body facing the interior surface of the upper body can be separated from the interior surface by an air gap. The at least one joining pin can be a single joining pin. The at least one joining pin can be fixedly coupled to at least one of the upper body and the lower body with an adhesive. 
     In another aspect, a helmet can comprise an upper body, a lower body positioned at least partially inside the upper body, and at least one joining pin located within both the lower body and the upper body, bridging and coupling the lower body and the upper body. 
     The helmet can further comprise the upper body comprising an interior surface comprising a locking flange, and the lower body comprising an edge in contact with the locking flange of the upper body. The locking flange can be proximate a front rim of the upper body, and the at least one joining pin can be proximate a rear rim of the upper body. At least a portion of an exterior surface of the lower body facing an interior surface of the upper body can be separated from the interior surface by an air gap. In some instances the at least one joining pin can be a single joining pin. In other instances the at least one joining pin can be at least two joining pins. In another aspect, the helmet can further comprise a basket pair comprising an upper basket comprising a pin receiver, the upper basket at least partially embedded within the upper body. A lower basket can comprise a pin aperture, the lower basket being at least partially embedded within the lower body and positioned such that the pin aperture is aligned with the pin receiver of the basket pair. The at least one joining pin can be positioned inside both the pin aperture and the pin receiver of the basket pair. The helmet can further comprise the at least one joining pin being releasably coupled to at least one of the pin receiver and the pin aperture of the respective basket pair. The upper basket of the basket pair can be in-molded within the upper body, and the lower basket of the basket pair can be in-molded within the lower body. 
     In another aspect, a method of assembling a helmet comprising an upper body and a lower body can comprise providing an upper body of the helmet, inserting a lower body of the helmet into the upper body of the helmet, and inserting a joining pin into both the lower body and the upper body through an interior surface of the lower body, such that the joining pin bridges and couples the lower body and the upper body. 
     The method of assembling the helmet can further comprise rotating the lower body within the upper body until an edge of the lower body is in contact with a locking flange on an interior surface of the upper body. The method can further comprise aligning the lower body with the upper body to form a basket pair comprising an upper basket in-molded within the upper body and a lower basket in-molded within the lower body, the lower basket comprising a pin aperture aligned with a pin receiver of the upper basket, and inserting the joining pin into both the lower body and the upper body by inserting the joining pin into the pin aperture and the pin receiver of the basket pair. The joining pin can be releasably coupled to at least one of the pin receiver and the pin aperture of the respective basket pair. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The written description is presented in conjunction with the appended drawings, where like designations denote like elements, and: 
         FIG. 1  is a side view of a helmet with mechanically joined helmet bodies; 
         FIG. 2  is a bottom view of the helmet of  FIG. 1 ; 
         FIG. 3A  is a cross-sectional side view of the helmet of  FIG. 1 ; 
         FIG. 3B  is a cross-sectional side view of a helmet comprising two joining pins; 
         FIG. 4  is a perspective view of an embodiment of an upper basket; 
         FIG. 5  is a perspective view of an embodiment of a lower basket; 
         FIG. 6  is a perspective view of an embodiment of a joining pin; 
         FIG. 7A  is a cross-sectional view of a lower body being rotated within an upper body; 
         FIG. 7B  is a cross-sectional view of a lower body aligned with an upper body; 
         FIG. 7C  is a close-up cross-sectional view of a joining pin being inserted into a basket pair; and 
         FIG. 7D  is a close-up cross-sectional view of a joining pin being captured within a basket pair. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure, its aspects and implementations, are not limited to the specific helmet or material types, or other system component examples, or methods disclosed herein. Many additional components, manufacturing and assembly procedures known in the art consistent with helmet manufacture are contemplated for use with particular implementations from this disclosure. Accordingly, for example, although particular implementations are disclosed, one or more of such implementations and implementing components may comprise any components, models, types, materials, versions, quantities, or the like as is known in the art for such systems and implementing components, consistent with the intended operation. 
     The word “exemplary,” “example,” or various forms thereof are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” or as an “example” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Furthermore, examples are provided solely for purposes of clarity and understanding and are not meant to limit or restrict the disclosed subject matter or relevant portions of this disclosure in any manner. It is to be appreciated that a myriad of additional or alternate examples of varying scope could have been presented, but have been omitted for purposes of brevity. 
     While this disclosure includes a number of embodiments in many different forms, there is shown in the drawings and will herein be described in detail particular embodiments with the understanding that the present disclosure is to be considered as an exemplification of the principles of the disclosed methods and systems, and is not intended to limit the broad aspect of the disclosed concepts to the embodiments illustrated. 
     A function of a helmet can be to provide protection to the wearer while minimizing interference with the performance and enjoyment of an otherwise dangerous activity. A helmet may be shaped to provide both protection and comfort. For example, a helmet may be shaped to maximize ventilation, or reduce weight. Some helmets are made up of two or more bodies of energy-absorbing material to form shapes that would be difficult, if not impossible, to achieve in a single molded piece. 
     Contemplated in this disclosure is a helmet having mechanically joined helmet bodies.  FIGS. 1-3  depict non-limiting embodiments of a helmet  100  comprising an upper body  102  and a lower body  104 . As shown, the helmet  100  can optionally comprise at least one locking flange  200  that can be positioned on, or formed as part of, a surface of the helmet, such as an interior surface  310  of the upper body  102 , and can further be disposed at a front, side, or rear of the helmet  100 . In other instances the locking flange  200  can be positioned on, or formed as part of, an outer surface  312  of the lower body  104 , such as at front, side, or rear of the helmet  100 . While the helmet  100  has been shown with the non-limiting example of two bodies, for example the upper body  102  and the lower body  104 , additional bodies including intermediate or interstitial bodies can also be used, and one or more locking flanges  200  can also be present on the interstitial bodies. An edge  202  can be formed and mateably coupled or positioned adjacent the locking flange  200 . When more than one flange  200  is present, more than one edges  202  can be correspondingly coupled or positioned the more than one flanges  200 . The lower body  104  can optionally comprise an edge  202  proximate the locking flange  200 . Furthermore, the helmet  100  comprises a joining pin  300  inside of and bridging the upper body  102  and the lower body  104 . According to various embodiments, the locking flange  200  prevents the lower body  104  from rotating forward out of the upper body  102 , while the joining pin  300  prevents the lower body  104  from rotating backward out of the upper body  102 ; together, the flange  200  and pin  300  prevent the lower body  104  from being pulled linearly out of the upper body  102 . 
     Mechanically joining the lower body  104  and the upper body  102  of a helmet  100  using one or more joining pins  300 , locking flanges  200 , or both, is advantageous over conventional joining methods. Conventional helmets are made by joining helmet bodies with adhesives, or by in-molding the helmet bodies together. In-molding the bodies together does not allow for all of the tooling advantages possible when making helmets from two or more bodies, nor does it allow for a gap between helmet bodies. In-molding the bodies together can also be expensive and time consuming. Joining the bodies with adhesives can also be time consuming, adding additional processing and expense. Mechanically joining the helmet bodies, as shown in the non-limiting examples of  FIGS. 1-3 , may be faster, less expensive, and provide more freedom in usable helmet body shapes than conventional methods. 
     The non-limiting examples of a helmet  100  shown in  FIGS. 1-3  comprise an upper body  102  and a lower body  104 . In some embodiments, a helmet  100  may be assembled by mechanically joining two helmet bodies. In other embodiments, more than two helmet bodies may be joined using the methods contemplated herein. While many of the embodiments discussed herein focus on the mechanical joining of an upper body with a lower body, those skilled in the art will recognize that these methods and examples may be applied to helmets having more than two bodies, as well as a single body comprising multiple components, portions, or parts. 
     The upper body  102  and lower body  104  may include any desirable number and type of shells, layers, energy management materials, and the like known in the art for helmets. In some embodiments, a helmet body, such as the upper body  102 , lower body  104 , or both, may comprise or be formed of plastic, polymer, foam, or other suitable energy-absorbing material or impact liner to absorb, deflect, or otherwise manage energy and to contribute to energy management for protecting a wearer during impacts. The upper body  102  and lower body  104  can include, without limitation, expanded polystyrene (EPS), expanded polypropylene (EPP), expanded polyurethane (EPU), expanded polyolefin (EPO), or other suitable material. When formed as an in-molded helmet, the upper body  102  and lower body  104  can be formed with one or both of the upper body  102  and lower body  104  being bonded directly to each other or to an additional shell or protective shell, such as the type used in hard shell helmets or soft shell helmets. In some embodiments, a helmet body, such as the upper body  102 , lower body  104 , or both, may be composed entirely of energy management material. In other embodiments, a helmet body may itself be composed of multiple materials, or may be layered in nature. Advantageous over the conventional method of in-molding helmet bodies together, these joining methods may be used both with helmet bodies and materials that are compatible, and are not compatible, with in-molding. In any event, the upper body  102  and lower body  104  can absorb, attenuate, or manage energy from an impact by bending, flexing, crushing, or cracking. 
     The helmet body, such as the upper body  102 , lower body  104 , or both, may also comprise one or more shells or outer shells, which can, without limitation, be formed of a plastic, resin, fiber, or other suitable material including polycarbonate (PC), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), polyethylene (PE), polyvinyl chloride (PVC), vinyl nitrile (VN), fiberglass, carbon fiber, or other similar material. The shells can be stamped, in-molded, injection molded, vacuum formed, or formed by another suitable process. The shells can provide a space into which the upper body  102  and lower body  104  may be disposed. The shells can also provide a smooth aerodynamic finish, a decorative finish, or both, for improved performance, improved aesthetics, or both. As a non-limiting example, the shells can comprise a PC shell that is in-molded in the form of a vacuum formed sheet, or is attached to the upper body  102 , the lower body  104 , or both, with, e.g., an adhesive. The shells, upper body  102 , and lower body  104  can also be permanently or releasably coupled, using any suitable chemical or mechanical fastener or attachment device or substance including without limitation, an adhesive, permanent adhesive, PSA, foam-core adhesive, tape, two-sided tape, mounting foam adhesive, fastener, clip, cleat, cutout, tab, snap, rivet, hog ring, or hook and loop fasteners. 
       FIG. 3A  shows a non-limiting example of a cross-sectional side view of the helmet  100  taken along section line  3 A- 3 B shown in  FIG. 2 . More specifically,  FIG. 3A  shows the upper body  102  is mechanically joined with the lower body  104  by a locking flange  200  and a joining pin  300 . As shown, the interior surface  310  of the upper body  102  is mated with, or disposed against, an outer surface  312  of the lower body  104 . In some embodiments, the contact between an upper body  102  and a lower body  104  may be continuous. In other embodiments, such as the non-limiting example shown in  FIG. 7B , there may be a gap  702  between the upper and lower bodies, at least between the interior surface  310  of the upper body  102  and a portion  700  of the exterior surface of the lower body facing the interior surface  310  of the upper body. A presence of a gap between the upper body  102  and the lower body  104  can assist in energy management, and may provide for intermediate mechanical structures, such as covers for vents, and thus can enable features that might otherwise be unavailable or cost-prohibitive for unitary or monolithically formed bodies. As mentioned above, the gap between the upper body  102  and the lower body  104  may be desirable for energy management reasons, such as allowing bodies to slip against each other to absorb rotational impact energy, and could also contain materials beneficial for energy management that may not be compatible with in-molding. 
     As shown in  FIGS. 2 and 3A , the helmet  100  can comprise a locking flange  200 , which can be integrally formed as part of a monolithically formed upper helmet body  102 , or alternatively a separate or discrete piece coupled to the upper helmet body  102 . As a non-limiting example, the present description shows the locking flange  200  can be a projection on the interior surface  310  of the upper body  102  which obstructs movement of one or more of a particular type (e.g. rotational or linear), or a particular direction (e.g. to the front or to the side) of one helmet body (e.g. the lower body  104 ) with respect to another helmet body (e.g. the upper body  102 ). Specifically, the locking flange  200  shown in the non-limiting embodiments of  FIGS. 2, 3A, and 3B  can prevent the lower body  104  from rotating forward or being pulled directly downward, with respect to the upper body  102 . 
     As shown, helmet  100  can comprise a single locking flange  200 , centered near the front rim  204  of the upper body  102 . In some embodiments, the locking flange  200  of an upper body  102  may be a short segment, while in others the locking flange  200  may be long. For example, in an embodiment, the locking flange  200  may extending along a majority of the front rim  204  of the upper body  102 . In various embodiments, the length, thickness, or both of the locking flange  200  may depend on the properties of the material with which it and the upper body  102  are made. 
     In some embodiments, such as the non-limiting example shown in  FIG. 2 , a helmet  100  may employ a single locking flange  200 . In other embodiments, the upper body  102  may comprise multiple locking flanges  200 . In some embodiments, gaps between multiple locking flanges may be employed to create air channels that may facilitate ventilation through the lower body  104 . In other embodiments, protrusions from the lower body  104  may fill gaps between locking flanges  200  for improved stability. 
     As shown in  FIGS. 3A and 3B , the locking flange  200  can be mated with an edge  202  of the lower body  104 . In some embodiments, the edge  202  may be friction-fit with the locking flange  200 , while in others edge  202  may simply be resting against the flange  200 . Furthermore, in some embodiments, a locking flange  200  may be mated with an edge  202 , while in others the contact between the locking flange  200  and an edge  202  may be non-continuous. 
     In some embodiments, including the non-limiting examples shown in  FIGS. 3A and 3B , the surface of the locking flange  200  that is facing the edge  202  may be flat. In other embodiments, the surface of the locking flange  200  that faces the edge  202  may be contoured. As an option, the contoured surface may be smooth and continuous, or it may be made up of multiple surfaces and have edges and corners. A contoured surface of interaction between a locking flange and an edge of a lower body may improve the inhibition of certain types or directions of movement (e.g. it may bolster against side to side movement between the two helmet bodies  102 ,  104 ). 
     The non-limiting examples of helmets  100  shown in  FIGS. 2-3  have a locking flange  200  located near a front rim  204  of the upper body  102 . Depending upon the intended overall helmet design, and the shape of the helmet bodies, a locking flange  200  may be positioned at a variety of locations on the interior surface  310  of the upper body, according to various embodiments. For example, in one embodiment, the upper body  102  may have a locking flange  200  located on the lateral sides or at a rear of the helmet  100 . 
     As shown in the non-limiting examples of  FIGS. 3A and 3B , the helmet  100  can comprise at least one joining pin  300 . Specifically,  FIG. 3A  shows a helmet  100  having a single joining pin  300 , while the helmet  320  shown in  FIG. 3B  has two joining pins  300 . In the context of the present description and the claims that follow, a joining pin comprises an object that may be placed inside of two or more helmet bodies (e.g. upper body  102  and lower body  104 ) to bridge those bodies, joining them and preventing particular types, directions, or both of movement of one of the bridged bodies with respect to another, as discussed in greater detail with respect to  FIG. 6 . 
     The non-limiting examples shown in the figures and described herein are directed toward embodiments where an upper body  102  is joined with a lower body  104  by a joining pin  300 . However, it should be understood that these methods and techniques may also be applied in embodiments where a joining pin  300  is inside of, bridges, and joins three or more helmet bodies. 
     In some embodiments, the joining pin  300  may be inserted directly into the material of the helmet bodies  102 ,  104  that are being joined. In other embodiments, the joining pin  300  may be held within one or more snap baskets, baskets, or attachment structures, while bridging the helmet bodies  102 ,  104 . For example, each joining pin  300  in the non-limiting examples shown in  FIGS. 3A and 3B  is shown held inside a basket pair  302  comprising a lower basket  304  inside the lower body  104  and an upper basket  306  inside the upper body  102 . Baskets such as these may serve to provide a strong, easy to assemble, economical union between the bodies  102 ,  104 , and may also be used to prevent the joining pin  300  from being removed, once inserted, according to various embodiments. Upper baskets  306  will be discussed in greater detail with respect to  FIG. 4 , while lower baskets  304  will be discussed in greater detail with respect to  FIG. 5 . 
     Like a locking flange  200 , a joining pin  300  may be used to prevent a particular type, direction, or both, of movement of one helmet body with respect to another, and may be used in conjunction with a locking flange. For example, in the non-limiting embodiments shown in  FIGS. 3A and 3B , a joining pin  300  is used in conjunction with a locking flange  200  to join the helmet bodies and prevent the lower body  104  from being removed from inside of the upper body  102 . In some embodiments, two or more helmet bodies may be joined solely using joining pins  300 , such as a first joining pin  300  at a front of the helmet  100  and a second joining pin at a rear of the helmet  100 . Alternatively, any number and location of joining pins according to the configuration and design of the helmet  100  can also be used. In other embodiments, two helmet bodies may be joined using a locking flange combined with another form of joining, such as those indicated above. For example, in one embodiment, two helmet bodies may be joined using a locking flange combined with an adhesive applied opposite the locking flange. This may be advantageous over using only adhesive, as a smaller amount of adhesive could be used, speeding up an assembly process and reducing helmet cost. 
     In various embodiments, two or more helmet bodies may be joined by one or more joining pins  300  used in conjunction with another method of joining, including but not limited to locking flanges  200 , adhesives, or other methods and techniques described above. Joining a lower body  104  with an upper body  102  relying solely on locking flanges  200  would be difficult, as the lower body  104  needs to be able to be inserted into the upper body  102 . However, using a locking flange  200  in conjunction with one or more joining pins  300  is advantageous in that the locking flange  200  can reduce the number of parts (e.g., joining pins) or steps needed to assemble the helmet. 
     As shown in  FIGS. 3A and 3B , a joining pin  300  can be located proximate a rear rim  308  of the upper body  102 , opposite a locking flange  200  proximate the front rim  204  of the upper body. Similar to locking flanges  200 , joining pins  300  may be positioned anywhere on the helmet to prohibit a variety of types or directions of relative movement between helmet bodies, according to various embodiments. The types or directions of relative movement prohibited may depend upon the position of a joining pin  300  within a helmet  100 . 
     In some embodiments, a joining pin  300  may be located opposite a locking flange  200 . In other embodiments, a joining pin  300  may be located proximate a locking flange  200 . For example, in one embodiment, a joining pin  300  may be located near a locking flange  200  while still positioned such that the combined types and directions of relative movement of helmet bodies prohibited by the locking flange  200  and joining pin  300  prevent the removal of the lower body  104  from inside the upper body  102 . 
     The non-limiting embodiment shown in  FIG. 3A  employs a single joining pin  300 , while the non-limiting embodiment shown in  FIG. 3B  uses two joining pins  300 . According to various embodiments, multiple joining pins  300  may be used to join a lower body  104  with an upper body  102 . For example, in one embodiment where the upper and lower bodies comprise a number of delicate features (e.g. shapes having many voids to improve ventilation), it may be desirable to distribute any strain put on the joined bodies (e.g. force applied to the upper body while the lower body is in contact with a head) across a number of locations bridged by joining pins rather than allowing a single joining pin to receive all the strain or loading. 
     In the non-limiting examples shown in  FIGS. 3A, 3B, 7C, and 7D , a joining pin  300  is inserted through an interior surface  314  of the lower body  104 . In some embodiments, joining pins  300  may be inserted into the helmet bodies through an interior surface of the lower body  104 . Such an insertion point may be covered up by a fit system or padding sometimes employed in conventional helmets, and would not require an opening in any sort of outer shell formed on the upper body  102 . In other embodiments, joining pins  30  may be inserted through an exterior surface of the upper body  102 . 
     In some embodiments, a joining pin  300  may be inserted to bridge two helmet bodies by piercing the helmet bodies with the joining pin. In other embodiments, including those shown in  FIGS. 3 and 7 , a joining pin  300  may be inserted through a channel  318  formed in at least one of the helmet bodies. Use of a channel  318  can facilitate proper placement of the pin  300  when joining one or more baskets  304 ,  306 , whereas without a formed channel, it may be difficult to locate a basket  304 ,  306  embedded within a helmet body for insertion. 
     In some embodiments, the joining pin  300  may be inserted directly into the material of the upper body  102  and the lower body  104  to join the bodies. In other embodiments, the joining pin  300  may be inserted into one or more baskets, such as the non-limiting examples of baskets  304 ,  306  shown in  FIGS. 4 and 5 . According to various embodiments, joining pins  300  may be composed of materials that are harder, tougher, stiffer, or stronger than the energy absorbing materials used in helmet bodies  102 ,  104 . In such embodiments, directly inserting the joining pin  300  into the helmet bodies  102 ,  104 , may over time, result in a deformation of the helmet body material around the pin  300  caused by the pin  30  compressing, cracking, piercing, or otherwise deforming the material of the helmet bodies,  102 ,  104 . Such deformation of the helmet bodies  102 ,  104  could allow the helmet bodies to move relative to each other and possibly be separated. However, inserting the same pin  300  into a basket pair  302 , when the pin  300  and the basket pair  302  are made of the same or similar material may delay, reduce, or prevent damage to the helmet bodies  102 ,  104 , and possible loosening of the pin  300  by having the basket pairs  302  spreading or transferring forces from the pin  300  across a larger area of the basket pairs  302 . The use of one or more baskets  304 ,  306  in conjunction with a joining pin  300  may result in a stronger, more durable coupling between helmet bodies  102 ,  104 , according to various embodiments. Additionally, baskets  304 ,  306  such as those shown in  FIGS. 4 and 5  may trap an inserted joining pin  300 , according to some embodiments. Capturing a joining pin  300  inside a basket or basket pair  302  such that it cannot easily be removed may result in a stronger, more reliable coupling between helmet bodies. 
     Baskets  304 ,  306  meant to contain a joining pin  300  may be composed of a variety of materials, according to various embodiments. In some embodiments, baskets may be composed of a thermoplastic, such as nylon, or other plastics known in the art. In other embodiments, baskets may be composed of metallic materials, wood, cellulose, fiber, fiberglass, carbon fiber, textiles, or other similar materials. 
       FIG. 4  shows a non-limiting example of an upper basket  306  having a pin receiver  400 , a barb  404 , and an anchor  402 . In the context of the present description, an upper basket  306  can be a structure configured to be at least partially embedded within the upper body  102  and capable of receiving the joining pin  300 . The exemplary embodiment shown in  FIG. 4  comprises wings, supports, flanges, or net  406  on either side, increasing the surface area of interaction with the material of the upper body  102  in which it is embedded, providing stability to the joining pin  300  and anything else coupled to the upper basket  306 . In some embodiments, an upper basket  306  may be embedded in an upper body  102  during an injection molding process, or in-molded, as is known in the art. In other embodiments, an upper basket  306  may be incorporated into an upper body  102  after the upper body  102  has been formed through a variety of techniques including but not limited to adhesives and direct insertion. The geometry of an upper basket  306  may depend upon how it is to be incorporated into an upper body  102  (e.g. wings  406  are well adapted for in-molding, a threaded outer surface may be well adapted for insertion after body formation), according to various embodiments. 
     As shown, the upper basket  306  of  FIG. 4  comprises a pin receiver  400 . In the context of the present description, a pin receiver  400  can be a structure within a basket adapted to contain at least the leading portion of a joining pin  300 . The leading portion of a joining pin  300  can be the portion first inserted into the helmet bodies  102 ,  104 . In some embodiments, including the non-limiting example shown in  FIG. 4 , the pin receiver  400  may comprise a barrier that prevents the joining pin  300  from being inserted beyond the pin receiver  400 . In other embodiments, a pin receiver  400  may be open-ended, allowing a joining pin  300  to pass completely through if insertion is not terminated. 
     According to some embodiments, an upper basket  306  may serve to trap a joining pin  300  such that once inserted, it is not easily removed. According to some embodiments, a barb  404  may be used to capture a joining pin  300  within a basket. A barb  404 , and capturing joining pins in general, is discussed in greater detail with respect to  FIGS. 7C and 7D . 
     According to some embodiments, a basket may further comprise a structure to facilitate the coupling of other objects to a helmet body, in addition to the joining of one helmet body to another. For example, the non-limiting embodiment of an upper basket  306  shown in  FIG. 4  comprises an anchor  402  to which a strap may be attached. In some embodiments, an anchor  402  may be embedded within a helmet body and may require a channel through the helmet body to allow attachment to the anchor. In other embodiments, an anchor  402  may be positioned outside a helmet body to allow for easier access or positioning for coupling a particular item or type of item, such as a camera. According to various embodiments, an upper basket  306  may comprise one or more anchors  402  configured to couple with straps, fit systems, accessories such as cameras and lights, and other items known in the art that may be coupled to a helmet. 
       FIG. 5  shows a non-limiting example of a lower basket  304  having a pin aperture  500 . In the context of the present description and the claims that follow, a lower basket  304  is a structure configured to be at least partially embedded within a lower body  104  and capable of receiving a joining pin  300 . Like the non-limiting example of an upper basket  306  shown in  FIG. 4 , the lower basket  304  shown in  FIG. 5  has wings  406  on either side, advantageous for embedding the lower basket  304  in a lower body  104  during a molding process, as is known in the art. Similar to an upper basket  306 , a lower basket  304  may also be incorporated into a helmet body after it has been formed, according to various embodiments. 
     As shown, the lower basket  304  of  FIG. 5  comprises a pin aperture  500 . In the context of the present description and the claims that follow, a pin aperture  500  is a structure within a basket adapted to contain at least a portion of a joining pin  300 . Unlike some embodiments of a pin receiver  400 , a pin aperture  500  can be open ended. Furthermore, the pin aperture  500  shown in  FIG. 5  need not be configured to capture or trap a joining pin  300 . However, in various embodiments, a pin aperture  500  may be configured to trap a joining pin  300 . 
     As shown in the non-limiting examples of  FIGS. 4 and 5 , the upper basket  306  can comprise a pin receiver  400 , while the lower basket  304  comprises a pin aperture  500 . Such an arrangement is configured for insertion of a joining pin  300  into the basket pair through an interior surface  314  of the lower body. In embodiments where a joining pin  300  is inserted into a basket pair  302  through an exterior surface of the upper body, the upper basket may comprise a pin aperture  500  while the lower basket comprises a pin receiver  400 . 
       FIG. 6  shows a non-limiting example of a joining pin  300 . As stated before, a joining pin is an object that may be placed inside of two or more helmet bodies (e.g. upper body  102  and lower body  104 ) to bridge those bodies, joining them and preventing particular types or directions of movement of one of the bridged bodies with respect to another. A joining pin  300  may be constructed of any material known in the art, including but not limited to thermoplastics such as nylon and injection mold plastics, as well as metallic materials, or any other suitable material. 
     The non-limiting example of a joining pin  300  shown in  FIG. 6  is a flat, rounded rectangle. In other embodiments, a joining pin  300  may be one of a variety of shapes. As a specific example, in one embodiment, the joining pin may be cylindrical, which may be advantageous for joining pins inserted directly into the material of helmet bodies. In other embodiments, the joining pin  300  may have an irregular polygonal shape or an oval cylindrical shape or any other shape forming an elongated pin for restricting relative movement of helmet bodies, as previously discussed. A size or dimensions of the joining pin  300  may be of any size that fits or works in conjunction with the helmet  100 , including a length L in a range of 1-40 millimeters (mm), 3-30 mm, or 7-15 mm. A width or diameter W of the joining pin  300  may be in a range of 1-40 mm, 2-15 mm, or 4-8 mm. A thickness or diameter T of the joining pin  300  may be in a range of 0-10 mm, 1-5 mm, or 1-3 mm. 
     The non-limiting example of a joining pin  300  shown in  FIG. 6  is adapted for use in conjunction with a basket pair  302 . In other embodiments, a joining pin may have different geometry advantageous for direct insertion into helmet body material. For example, in one embodiment, a joining pin  300  may have series of narrow fins which may increase the surface area of interaction between the pin and the material of a helmet body, providing improved grip. 
     According to some embodiments, a joining pin  300  may be trapped, or releasably coupled, within a basket or basket pair  302 . For example, in the non-limiting embodiment of a joining pin  300  shown in  FIG. 6 , the joining pin  300  comprises a catch  600 . A catch  600  may be paired with a barb  404  to capture a joining pin  300  in a basket or basket pair  302 . In some embodiments, a catch  600  may be an indentation in a joining pin  300 , while in others a catch  600  may be defined by a projection extending out from the surface of a pin. Catches and barbs will be discussed in greater detail with respect to  FIGS. 7C and 7D . 
     In some embodiments, a joining pin  300  may be designed to facilitate quick insertion. For example, the non-limiting embodiment shown in  FIG. 6  may be inserted either side up, in one of two directions (as indicated by the arrows on the surface). In other embodiments, a joining pin may be shaped such that it may be inserted from any direction. However, in some embodiments, the pin  300  may be shaped to give it strength against strain caused by attempts to move helmet bodies in a particular direction or manner, and such strengthening may result in the pin needing to be inserted in a particular direction. 
       FIGS. 7A-7C  show a non-limiting example of a helmet  100  being assembled, joining an upper body  102  with a lower body  104  using a locking flange  200  and a joining pin  300 .  FIGS. 7A and 7B  show a lower body  104  being fit inside an upper body  102  and rotated until an edge  202  of the lower body  104  is in contact with a locking flange  200  of the upper body  102 . As shown in  FIG. 7B , when the lower body  104  has been fully rotated to engage with the locking flange  200  of the upper body  102 , the lower basket  304  is aligned with the upper basket  306  to form a basket pair  302 . 
       FIG. 7C  shows a joining pin  300  being inserted into a channel  318  on the interior surface  314  of the lower body  104 . In some embodiments, a joining pin  300  may be inserted manually, while in others the insertion may be performed by a machine. According to various embodiments, once the pin  300  is inside the channel  318 , a tool or other elongated implement may be used to push the joining pin  300  into a basket pair  302 . 
     According to various embodiments, a joining pin  300  may be trapped inside a basket or basket pair  302  by various structures, designs, or arrangements. For example, in one embodiment, an adhesive may be applied to the joining pin  300  after insertion into a basket. In other embodiments, a joining pin  300  may be adhered directly to the material of a helmet body. 
     In other embodiments, a joining pin  300  may be trapped within a basket or basket pair  302  through the interaction of complimentary structures, such as a catch and a barb. As shown in the non-limiting example of  FIG. 7C , the joining pin  300  comprises a catch  600  having a retention surface  712 . In the context of the present description, a retention surface  712  is a surface on a catch configured to constrain movement of a barb once a relative position of the barb and catch has been achieved. As shown, a retention surface  712  can extend from a catch base  714  to a catch peak  716 . 
     Furthermore, as shown in  FIG. 7C , the pin receiver of the upper basket  306  can comprise two barbs  404 , each having an insertion surface  718 . In the context of the present description, an insertion surface  718  can be a surface on a barb  404  that extends from a barb base  706  to a barb peak  708 , and can be angled away from both the barb base  706  and a relative direction of motion  710  of the barb during insertion of the pin into the basket. In some embodiments, a joining pin  300  may have one or more catches, and one or both baskets of a basket pair  302  may have one or more barbs. In other embodiments, the pin  300  may have one or more barbs, and one or more catches may be located within the basket pair. 
       FIG. 7D  shows a pin trapped in a basket pair according to an embodiment.  FIG. 7D  shows the joining pin  300  trapped within the basket pair  302 , after being inserted along an insertion path  726  until the displacement of a leading peak  720  from the insertion path  726  is greater than the displacement of a trailing peak  722  from the insertion path  726  and less than the displacement of a trailing base  724  from the insertion path  726 . In the context of the present description, a leading peak  720  is a peak, either the barb peak  708  or the catch peak  716 , farthest away from the interior surface  314  of the lower body proximate the insertion path  726 . Furthermore, a trailing peak  722  can be a peak, the barb peak  708  or the catch peak  716 , which is not the leading peak. The trailing base  724  can be the base, either the barb base  706  or the catch base  714 , which can be part of the same surface as the trailing peak  722 . When such conditions are met, the barb collides with the catch, preventing the joining pin  300  from being removed from the basket pair  302 . In other words, when the joining pin  300  of  FIG. 7C  is inserted into the basket pair  302 , the barb  404  of the upper basket  306  can deflects when the pin  300  hits the insertion surface  718 . Once the pin  300  is fully inserted, the barb  404  can drop into the catch  600  of the pin  300 , trapping the pin  300 , either permanently or releasably. 
     Where the above examples, embodiments and implementations reference examples, it should be understood by those of ordinary skill in the art that other helmet and manufacturing devices and examples could be intermixed or substituted with those provided. In places where the description above refers to particular embodiments of helmets and assembly methods, it should be readily apparent that a number of modifications may be made without departing from the spirit thereof and that these embodiments and implementations may be applied to other to helmet assembly technologies as well. Accordingly, the disclosed subject matter is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the disclosure and the knowledge of one of ordinary skill in the art.