Patent Publication Number: US-2023137423-A1

Title: Adjustable shield for helmet

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims benefit of and priority to U.S. Provisional Patent App. No. 63/274,760, filed Nov. 2, 2021, which is incorporated herein by reference in its entirety for all purposes. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This present invention relates to helmets and face shields, and more specifically to adjustment of face shields attached to helmets. 
     Background 
     Helmets and face shields are used during sporting activities, such as winter sports. Wearers of these products need to protect their heads and eyes from injury or impact, which can be caused by environmental debris and/or harsh conditions. These helmets and face shields can be worn during the entire duration of the activity as well, which can last multiple hours. Accordingly, participants desire helmets and face shields that provide comfort and fit throughout the duration of the activity. Additionally, participants require helmets and face shields that provide comfort and fit to support their performance. 
     BRIEF SUMMARY OF THE INVENTION 
     According to aspects, a face shield fit adjustment system can include a frame to attach to a helmet. The frame can include a channel. The face shield fit adjustment system can also include a face shield slider to move within the channel of the frame while in an as-worn position between a first secured position such that a face shield is at a first distance from an eye of a wearer in an as-worn position, and a second secured position such that the face shield is at a second distance from the eye of the wearer in the as-worn position, the first distance being less than the second distance. The face shield fit adjustment system can also include a release to disengage the face shield slider to move the face shield slider between the first secured position and the second secured position. 
     In an aspect, the face shield slider can be releasably attached to a face shield to adjust the face shield relative to the eye of the wearer. 
     In an aspect, a helmet can include the face shield fit adjustment system and a face shield. The face shield can be adjusted with the face shield fit adjustment system to fit relative to the eye of the wearer. 
     In an aspect, the slider can be biased to the first secured position. 
     In an aspect, the face shield fit adjustment system can further include a frame member attached to the frame to hold the face shield slider in the first secured position and the second secured position. In an aspect, a distance along a longitudinal axis between the first secured position and the second secured position can be less than a length of the frame member. In an aspect, the distance can be in a range of approximately one millimeter to approximately 15 millimeters. In an aspect, the distance can be approximately one millimeter. In an aspect, the frame member can selectively engage teeth integral with the face shield slider in the first secured position and the second secured position. In an aspect, the frame member can include teeth that selectively engage the teeth of the face shield slider in the first secured position and the second secured position. 
     In an aspect, the face shield fit adjustment system can further include a face shield slider member pivotally attached to the face shield slider at a first end. The teeth of the face shield slider can be part of the face shield slider member. In an aspect, a free end of the face shield slider member can be coupled to the release. In an aspect, the face shield slider member can rotate to move between the first secured position and the second secured position. In an aspect, the face shield slider member can be biased to engage the frame member. 
     In an aspect, the face shield slider can include a protrusion that moves within the channel of the frame. 
     In an aspect, the face shield fit adjustment system can further include a second frame attached to the helmet. The second frame can include a second channel. The face shield fit adjustment system can further include a second face shield slider to move within the second channel of the second frame. The face shield slider can move with the second face shield slider between the first secured position and the second secured position. 
     In an aspect, the release can disengage the first face shield slider and the second face shield slider simultaneously to move the face shield slider between the first secured position and the second secured position. 
     According to aspects, a face shield attached to a face shield fit adjustment system can include a lens and a frame attached to the lens and to a face shield slider of the face shield fit adjustment system, the face shield slider moving within a channel of a helmet to adjust the lens relative to an eye of a wearer in an as-worn position. 
     In an aspect, the lens can be fixed in position relative to the eye of the wearer by engagement between the face shield and the helmet. 
     In an aspect, a lens tilt of the lens can change up to five degrees between a first secured position in the as-worn position and a second secured position in the as-worn position. 
     In an aspect, the face shield can further include a magnet disposed in a recess of an outrigger of the face shield to attach the face shield to the helmet and a magnet release. The magnet release can move the recess to detach the face shield from the helmet. The magnet release can be biased to not move the recess. 
     According to aspects, a helmet attached to a face shield fit adjustment system can include an upper shell. The helmet attached to a face shield fit adjustment system can also include a frame attached to the upper shell. The frame can include a channel to receive a face shield slider of the face shield fit adjustment system. The helmet attached to a face shield fit adjustment system can also include a frame member attached to the frame to engage the face shield slider in a first secured position and a second secured position and a lower shell attached to a release of the face shield fit adjustment system. The release can move from a first position to a second position to disengage the frame member from the face shield slider to move the face shield slider in an as-worn position between a first secured position such that a face shield is at a first distance from an eye of a wearer in an as-worn position, and a second secured position such that the face shield is at a second distance from the eye of the wearer in the as-worn position, the second distance greater than the first distance. 
     In an aspect, a bottom edge of the lower shell can be coplanar with the release in the first position of the release. 
     In an aspect, the frame member can translate or rotate relative to a longitudinal axis when the release is in its second position. 
     In an aspect, the frame member can include a top toothed edge to engage the face shield slider. 
     In an aspect, the channel of the frame can be bounded by a track of the frame to receive an upper end of the face shield slider. 
     In an aspect, the helmet can further include a first magnetic interface to couple the helmet to a face shield in an engaged position and a second magnetic interface to couple the helmet to the face shield in a stowed position. Each of the first magnetic interface and the second magnetic interface can include a magnet disposed in a recess of the upper shell. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES 
       Some features herein are illustrated by way of example, and not by way of limitation, in the accompanying drawings. In the drawings, like numerals reference similar elements between the drawings. 
         FIG.  1    shows a perspective view of a helmet-shield adjustment system according to aspects. 
         FIG.  2    shows an assembly view of the adjustment system of  FIG.  1   . 
         FIG.  3    shows a perspective view of the helmet-shield adjustment system of  FIG.  1   . 
         FIG.  4    shows a side view of the helmet-shield adjustment system of  FIG.  1   . 
         FIG.  5    shows an assembly view of the face shield of  FIG.  1   . 
         FIG.  6    shows a side view of the adjustment system of  FIG.  1   . 
         FIG.  7    shows a side view of the adjustment system of  FIG.  1   . 
         FIG.  8    shows a side view of the adjustment system of  FIG.  1   . 
         FIG.  9    shows a side view of the adjustment system of  FIG.  1   . 
         FIG.  10    shows a side view of the helmet-shield adjustment system of  FIG.  1   . 
         FIG.  11    shows a side view of the adjustment system of  FIG.  1   . 
         FIG.  12    shows a side view of the helmet-shield adjustment system of  FIG.  1   . 
         FIG.  13    shows a side view of the helmet-shield adjustment system of  FIG.  1   . 
         FIG.  14    shows a cutout view of the helmet-shield adjustment system of  FIG.  13   . 
         FIG.  15    shows a side view of the helmet-shield adjustment system of  FIG.  1   . 
         FIG.  16    shows an adjustment system according to aspects. 
         FIG.  17    shows an adjustment system according to aspects. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present inventions will now be described in detail with reference to embodiments thereof as illustrated in the accompanying drawings, in which like reference numerals are used to indicate identical or functionally similar elements. References to “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. 
     The following examples are illustrative, but not limiting, of the present inventions. Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered in the field, and which would be apparent to those skilled in the art, are within the spirit and scope of the inventions. 
     Axes and planes discussed herein are with reference to a wearer&#39;s head in an upright vertical position. The systems and components thereof can be shifted in various activities. Movement of the systems and components thereof can be relative to this positioning. It should be understood that the systems and methods described herein are applicable to adjustment from an anterior positioning to a posterior positioning, from a posterior positioning to an anterior positioning, and between an anterior positioning and a posterior positioning. Reference to a first secured position with a posterior positioning and a second secured position with an anterior positioning do not indicate solely two positions for adjustment, but rather two separate positions within the adjustment range(s) described herein. Additionally, first and second secured positions described herein do not indicate the order of positioning. Accordingly, a second secured position can be set before a first secured position, and vice versa. 
     Systems and methods are described herein relating to helmet and face shields that provide improved fit and comfort. The face shield can be attached to the helmet and can be adjusted relative to the eyes of the wearer and the helmet while in an as-worn position. Accordingly, the wearer can adjust the face shield while wearing both the helmet and the face shield. The adjustment system can iteratively adjust the position of the face shield to achieve a desired fit. In an aspect, the face shield can correlate to a desired face pressure and/or distance from the eyes. Additionally, the position of the face shield can be selected to maintain a desired performance of the face shield lens. For example, the position of the face shield can be fixed in a first secured position, which can coincide with a posterior positioning where the face shield is closer to the eyes of the wearer and/or the helmet. The face shield can be adjusted to be fixed in a second secured position, which can coincide with an anterior positioning where the face shield is farther from the eyes of the wearer and/or the helmet relative to the posterior positioning. Adjustment can include translation and/or rotation. The system and methods described herein also show engaged and stowed positions of the face shield, where the wearer can stow the face shield on the helmet to keep the helmet and face shield coupled together. 
     To adjust the position of the face shield lens relative to the helmet and the eyes of the wearer, existing goggles can use straps. The straps can be attached to the goggles and can extend around a wearer&#39;s head and/or helmet to secure goggles to the wearer. The strap can be adjusted to fit tighter or looser around the wearer. However, adjustment of the straps can require removing the goggles from the wearer. Additionally, the wearer might not achieve an ideal adjustment. For example, a wearer might adjust the straps to be too tight or too loose, requiring additional fitting and readjustment. The wearer may settle on a workable configuration, which might not be the best configuration for the wearer. In contrast, fitting a face shield relative to the eyes of the wearer and/or the helmet in an as-worn position can allow the wearer to simultaneously determine and set their ideal face shield placement. This eliminates the inconsistencies inherent in adjustment that requires separation of goggles from a helmet and reduces the time and effort to find a desired fit. 
     The face shield system described herein can be adjustable and does not require the use of straps. The helmet can include a frame that is part of an adjustment system. The frame can include a channel. A slider, or a pawl, coupled to the face shield can move within the frame channel between secured positions. These positions can secure the face shield relative to the eyes of the wearer and/or the helmet. A release can be attached to the adjustment system to allow the face shield slider to move between different secured positions. In some aspects, the release can be a button or lever disposed on the shell of the helmet and accessible to the wearer from the exterior of the helmet. In some aspects, the adjustment system can include micro-adjustments. In this way, the face shield can be adjusted in small increments (e.g., in millimeters) to achieve a desired fit and performance of the face shield lens. 
     In some aspects, a strap can be added to the face shield described herein to adapt the face shield to other systems. The face shield can be modular and can function with additional helmet designs. 
     The adjustment system frame can be fixed to the helmet and can include a frame member. In some aspects, the frame member can have teeth. In some aspects, the teeth can be disposed along a frame member edge, e.g., a top edge. In some aspects, corresponding teeth can be disposed on a portion of the slider. In some aspects, the teeth can be integral with the slider. In some aspects, the slider teeth can be disposed along a bottom edge of a slider member. The slider teeth member and the frame member teeth can engage and disengage to move the face shield between different secured positions relative to the eyes of the wearer and/or the helmet. 
     In some aspects, the slider member can be pivotally attached to the slider. In an aspect, the slider member can have a pinned end attached to the slider and a free end opposite the pinned end. In some aspects, the free end can be coupled to the release. In an aspect, as the release is actuated, the slider member can be rotated about its pinned end to disengage the slider teeth from the frame member teeth, allowing the slider to move from a secured position. Accordingly, in some aspects, wearer actuation of a release rotates the slider member to disengage the slider member teeth from the frame member teeth. As the release button is actuated, the face shield can move to a desired secured position. Once a desired secured position is achieved, the wearer can let go of the release. The slider member can be biased to rotate such that the slider member teeth engage the frame member teeth, thereby maintaining the face shield in a secured position. Thus, the face shield can be secured as desired by the wearer relative to the eyes of the wearer and/or the helmet without needing to remove the face shield. Additionally, the adjustment system can allow the face shield to be adjusted while remaining in front of the eyes of the wearer such that the wearer can easily select and set desired face shield positioning. 
     A face shield can include a lens, a frame, and foam to provide an interface between the face shield and the wearer&#39;s face. These components can conform to the wearer&#39;s face. The face shield can include ends that attach to ends of the helmet. In some aspects, the face shield ends can be adjusted simultaneously. Accordingly, releasing the slider connected on one end can also release the slider at the other end of the face shield such that both ends of the face shield can be adjusted simultaneously. In this way, the wearer can simultaneously adjust the ends of the face shield relative to the eyes of the wearer and/or the helmet. Adjustment of both ends simultaneously can be desirable to facilitate an easier adjustment. This also allows the face shield to be adjusted with one hand. In some aspects, each end of the face shield can be adjusted independently. 
     Additionally, in some aspects, the face shield can both translate and rotate to achieve a desired fit and performance of the face shield lens, such as by achieving a desired rake or lens tilt. Accordingly, the face shield can be dynamically optimized while worn. Rake or lens tilt can be desirable for aesthetic reasons and/or to protect the eyes from environmental debris and harsh conditions. “Rake” can describe the condition of a lens in an as-worn position when the normal line of sight strikes a vertical tangent to the lens or lenses at a non-perpendicular angle. 
     The face shield lens can have optical qualities related to clarity, resolution, refraction, and field of vision. Higher optical qualities can be achieved when the wearer&#39;s straight ahead normal line of sight (LOS) extending from a center of the wearer&#39;s eye extends parallel to (or with deviations no more than approximately six degrees and no more than approximately three or four degrees) the optical center line (OCL) of the lens. In some aspects, the vertical tangent extends through the face shield lens. In some aspects, the wearer&#39;s straight ahead normal LOS intersects an anterior surface and a posterior surface of the face shield lens at an angle of approximately 90 degrees. Accordingly, the wearer&#39;s LOS can be substantially normal to the anterior surface and posterior surface of the face shield lens. In some aspects, the wearer&#39;s straight ahead normal LOS intersects an anterior surface and a posterior surface of the face shield lens at a non-perpendicular angle such that the face shield lens comprises a rake or lens tilt. In some aspects, a the wearer&#39;s straight ahead normal LOS extending from a center of the wearer&#39;s eye passes through a center of the lens with and without a rake or lens tilt. 
     The helmet can support the face shield in an engaged position and a stowed position. 
     In the engaged position, the face shield can be worn and functional in front of the eyes of the wearer. In the stowed position, the face shield can be stored on the helmet when not in use, but maintained with the helmet to prevent loss of the face shield, for example. The helmet can include an attachment interface, e.g., a magnetic interface, at a front of its shell to support the face shield in the engaged position. Similarly, the helmet can include an attachment interface, e.g., a magnetic interface, at a top of its shell to support the face shield in the stowed position. The face shield can include an attachment interface to attach to the helmet in the engaged position or the stowed position. A release can be included on the face shield to easily remove the face shield from the helmet. As with the adjustment system, a release can be located on one or both ends of the face shield to quickly and easily detach the face shield from the helmet. Actuating one release can release both ends such that one hand can be required for detaching the face shield from the helmet. 
     Based on the foregoing, the helmet and face shield described herein can provide comfort and fit to the wearer by adjusting the position of the face shield relative to the eyes of the wearer and/or the helmet in an as-worn position. Additionally, a desired lens performance can be achieved by allowing for translation and/or rotation of the face shield relative to the eyes of the wearer. In this way, wearers can quickly and easily select and set desired face shield positioning. These and other aspects will be described with reference to the figures. 
     As shown in  FIG.  1   , a helmet-shield adjustment system  1  can include a helmet  100 , an adjustment system  200 , and a face shield  300 . Helmet  100  can protect a wearer&#39;s head from injury, such as from impact, as well as from environmental debris and harsh conditions. Face shield  300  can similarly protect the wearer&#39;s eyes. In some aspects, the wearer can be a participant in an athletic sport, such as a snow sport. As a skier or a snowboarder, the wearer can experience harsh conditions from wind and light. Additionally, environmental debris such as snow and ice can impact the wearer. To minimize the impact of these factors and prevent debris from contacting the wearer&#39;s eyes, helmet  100  and face shield  300  can deflect debris, allowing the wearer to perform uninhibited and maintain visual awareness of their surroundings. Adjustment system  200  can adjust the position of face shield  300  relative to the wearer&#39;s eyes and/or helmet  100 . In this way, the wearer can optimize the performance of helmet  100  and face shield  300 . 
     Helmet  100  can include an upper shell  110 , a lower shell  120 , a chinstrap  130 , and an earcard  140 . In some aspects, upper shell  110  can include EPS (expanded polystyrene). In some aspects, lower shell  120  can be a hard shell. Helmet  100  and face shield  300  can be attached such that they are in an engaged position  20 . 
     With reference to  FIGS.  1 - 2   , adjustment system  200  can include a slider  230 , or a pawl. Adjustment system  200  can also include a frame  250  and a release  270 . In some aspects, adjustment system  200  or components thereof can be attached to face shield  300 . In some aspects, adjustment system  200  or components thereof can be releasably attached to face shield  300 . Similarly, in some aspects, adjustment system  200  or components thereof can be attached to helmet  100 . In some aspects, adjustment system  200  or components thereof can be releasably attached to helmet  100 . In some aspects, adjustment system  200  or components thereof can be attached to face shield  300  and helmet  100 . In some aspects, adjustment system  200  or components thereof can be releasably attached to face shield  300  and helmet  100 . In some aspects, face shield  300  can include adjustment system  200 . In some aspects, helmet  100  can include adjustment system  200  and face shield  300 . As described herein, face shield  300  can be adjusted with adjustment system  200  relative to the eyes of the wearer and/or helmet  100 . 
     In some aspects, frame  250  can be attached to helmet  100 . In some aspects, frame  250  can be attached to upper shell  110 . In some aspects, frame  250  can be attached to lower shell  120 . In some aspects, slider  230  can be attached to face shield  300 . In some aspects, frame  250  can include a channel having an upper channel  252  and/or a lower channel  256 . Slider  230  can move within upper channel  252  and/or lower channel  256  while helmet-shield adjustment system  1  is in an as-worn position. 
     As will be described further below, slider  230  can move between secured positions in which face shield  300  can be fixed in position relative to the eyes of the wearer and/or helmet  100 . Face shield  300  can be fixed in a first secured position in which face shield  300  can be located at a first distance from an eye of the wearer in an as-worn position and a second secured position in which face shield  300  can be located at a second distance from the eye of the wearer in an as-worn position, where the first distance is less than the second distance (D 1  and D 1 ′ respectively in  FIGS.  3 - 4   ). In an aspect, a first secured position can coincide with a posterior positioning such that face shield  300  can be closer to the eyes of the wearer and/or helmet  100 . In an aspect, a second secured positioning can coincide with an anterior positioning such that face shield  300  can be farther from the eyes of the wearer and/or helmet  100  relative to a first secured position. In this way, slider  230  can move within upper channel  252  and/or lower channel  256  to adjust face shield  300  relative to the eyes of the wearer and/or helmet  100  while face shield  300  and helmet  100  are worn. 
       FIG.  3    shows helmet-shield adjustment system  1  in engaged position  20 . As shown, helmet  100  and face shield  300  can be worn such that engaged position  20  coincides with an as-worn positon. A helmet plane HP can be aligned with a surface of helmet  100 , e.g., a front surface. An eye plane EP can lie on a surface of the eyes of the wearer and can be parallel to a coronal plane. A lens plane LP can be aligned with a surface of face shield  300 , e.g., a front surface. An anterior-posterior (AP) line  500  can extend between a posterior side to an anterior side of the wearer. This AP line  500  can extend within a sagittal plane. A tangent line  501  can extend through face shield  300 . 
     As shown, D 1  can be the distance between lens plane LP and eye plane EP. In some aspects, D 1  can represent the distance between face shield  300  and the eyes of the wearer. D 2  can be the distance between lens plane LP and eye plane EP. In some aspects, D 2  can represent the distance between face shield  300  and helmet  100 . 
       FIG.  4    shows helmet-shield adjustment system  1  in engaged position  20 . As shown, face shield  300  ( FIG.  3   ) can be adjusted in an as-worn position from the position of  FIG.  3    using adjustment system  200  to a second secured position. A second secured position can coincide with an anterior positioning in which face shield  300  can be farther from the eyes of the wearer and/or helmet  100  relative to a first secured position with a posterior positioning in which face shield  300  can be closer to the eyes of the wearer and/or helmet  100  ( FIG.  3   ). In some aspects, the adjustment can include translation and/or rotation. The adjustment to a second secured position from a first secured position of  FIG.  3    can be shown in  FIG.  4    by helmet plane HP′, eye plane EP′, lens plane LP′, face shield  300 ′, D 1 ′, and D 2 ′. In some aspects, the adjustment can be from the position of  FIG.  4    to the position of  FIG.  3   . 
     As shown in  FIG.  5   , face shield  300  can include a face shield lens  310  and frame  320 . In an aspect, frame  320  can be a TPU (thermoplastic polyurethane) frame. Frame  320  can be attached to face shield lens  310 . In an aspect, frame  320  can be integral with face shield lens  310 . Frame  320  can also be attached to slider  230  of adjustment system  200  ( FIG.  2   ). In some aspects, frame  320  can be attached to slider  230  via an outrigger  340 . For example, frame  320  can be attached to slider  230  via an outrigger  340  on either end  301  of face shield  300 . In an aspect, frame  320  and slider  230  can be integral. Accordingly, slider  230  can move within upper channel  252  and/or lower channel  256  to adjust the position of face shield lens  310  relative to the eyes of the wearer and/or helmet  100  in an as-worn position. In some aspects, face shield  300  can include a foam face  330  that can form a seal with the wearer&#39;s face as face shield  300  changes position relative to the eyes of the wearer and/or helmet  100  in an as-worn position. 
     With reference to  FIGS.  3 - 5   , in some aspects, a wearer&#39;s LOS extends from a center of the wearer&#39;s eyes. In some aspects, the wearer&#39;s straight ahead normal LOS intersects an anterior surface and a posterior surface of face shield lens  310  at an angle of approximately 90 degrees. Accordingly, the wearer&#39;s LOS can be substantially normal to the anterior surface and posterior surface of face shield lens  310 . In some aspects, a wearer&#39;s LOS is parallel to AP line  500  when the wearer&#39;s head is in an upright vertical position. In some aspects, the wearer&#39;s straight ahead normal LOS intersects an anterior surface and a posterior surface of face shield lens  310  at a non-perpendicular angle such that face shield lens  310  comprises a rake or lens tilt. In some aspects, a the wearer&#39;s straight ahead normal LOS extending from a center of the wearer&#39;s eye passes through a center of face shield lens  310  with and without a rake or lens tilt. 
     In some aspects, tangent line  501  can extend through face shield lens  310 . In some aspects, tangent line  501  can be parallel with a coronal plane. In some aspects, tangent line  501  can be perpendicular to AP line  500 . In some aspects, lens plane LP, which can be aligned with face shield lens  310 , can be oriented to be parallel to tangent line  501 . In this orientation, face shield lens  310  can be oriented with minimal rake or lens tilt. In some aspects, lens plane LP can be parallel to tangent line  501  in a first secured position. In some aspects, in a second secured position, lens plane LP′ can be oriented to be parallel to tangent line  501  such that face shield lens  310  has minimal rake or lens tilt. 
     In some aspects, face shield  300  and/or face shield  300 ′ and components thereof can be oriented to have a rake or lens tilt. In some aspects, as shown in  FIG.  4   , lens plane LP in a first secured position ( FIG.  3   ) can be oriented at an angle relative to tangent line  501 . In some aspects, the angle can provide a rake or lens tilt  312 . In some aspects, lens tilt  312  can be between one degree and five degrees. In some aspects, lens plane LP′ in a second secured position can be oriented at an angle relative to tangent line  501 . In some aspects, the angle can provide a rake or lens tilt  312 ′. In some aspects, face shield lens  310 ′ in a second secured position can be maintained at the same angle from tangent line  501  as lens tilt  312 . In some aspects, lens tilt  312 ′ can be between one degree and 15 degrees, such as between five degrees and 10 degrees, such as seven degrees. In some aspects, adjustment system  200  can provide rotational adjustment between a first secured position and a second secured position. In some aspects, the rake adjustment between lens tilt  312  in a first secured position and lens tilt  312 ′ in a second secured position can be between one degree and five degrees. In some aspects, face shield lens  310  can be curved. In some aspects, lens tilt  312  or lens tilt  312 ′ can vary across face shield lens  310  (e.g., across an upper edge to a lower edge of face shield lens  310 ). 
     In some aspects, adjustment between a first secured position with a posterior positioning and a second secured position with an anterior positioning ( FIGS.  3 - 4   ) can be along a plane parallel to AP line  500 . In some aspects, adjustment along a plane parallel to AP line  500  can be generally equal across face shield lens  310  (e.g., across an upper edge to a lower edge of face shield lens  310 ). In some aspects, adjustment along a plane parallel to AP line  500  can provide minimal shift in an inferior-superior direction (e.g., a direction parallel to tangent line  501 ). In some aspects, the shift in the inferior-superior direction can be less than approximately four millimeters, such as less than approximately three millimeters, such as less than approximately two millimeters. In some aspects, adjustment along a plane parallel to AP line  500  can provide minimal rake adjustment. In some aspects, the rake adjustment can be less than four degrees, such as less than three degrees, such as less than two degrees. In some aspects, the shift in the inferior-superior direction and/or a rake adjustment during adjustment along a plane parallel to AP line  500  can be minimized to maintain the wearer&#39;s LOS in the center of face shield lens  310 . 
     In some aspects, adjustment between a first secured position with a posterior positioning and a second secured position with an anterior positioning can be along a plane parallel to AP line  500 , in an inferior-superior direction, and/or with rake adjustment. In some aspects, this adjustment can maintain the wearer&#39;s LOS in the center of face shield lens  310 . Accordingly, the wearer&#39;s LOS can be in the center of face shield lens  310  in both a first secured position with a posterior positioning and a second secured position with an anterior positioning. 
     In some aspects, the adjustment between a first secured position with a posterior positioning and a second secured position with an anterior positioning ( FIGS.  3 - 4   ) along a plane parallel to AP line  500  can be represented by the difference between D 1  and D 1 ′. D 1  can be at a first secured position with a posterior positioning in which face shield  300  can be closer to the eyes of the wearer relative to a second secured position with an anterior positioning, and D 1 ′ can be at a second secured position with an anterior positioning in which face shield  300 ′ can be farther from the eyes of the wearer relative to a first secured position with a posterior positioning. In some aspects, the difference between D 1  and D 1 ′ can be between approximately five millimeters and approximately 30 millimeters, such as between approximately seven millimeters and approximately 25 millimeters, such as between approximately nine millimeters and approximately 20 millimeters, such as approximately 10 millimeters. In some aspects, the adjustment between a first secured position with a posterior positioning and a second secured position with an anterior positioning along a plane parallel to AP line  500  can be represented by the difference between D 2  and D 2 ′. D 2  can be at a first secured position with a posterior positioning in which face shield  300  can be closer to helmet  100  relative to a second secured position with an anterior positioning, and D 2 ′ can be at a second secured position with an anterior positioning in which face shield  300 ′ can be farther from helmet  100  relative to a first secured position with a posterior positioning. In some aspects, the difference between D 2  and D 2 ′ can be between approximately five millimeters and approximately 30 millimeters, such as between approximately seven millimeters and approximately 25 millimeters, such as between approximately nine millimeters and approximately 20 millimeters, such as approximately 10 millimeters. 
     As shown, face shield  300  ( FIG.  3   ) can include a lower edge  305  ( FIG.  3   ). In some aspects, the adjustment from a first secured position with a posterior positioning to a second secured position with an anterior positioning can be can be illustrated with reference to lower edge  305  and lower edge  305 ′ in  FIG.  3    and  FIG.  4   , respectively. Similarly, the adjustment from a second secured position with an anterior positioning to a first secured position with a posterior positioning can be can be illustrated with reference to lower edge  305 ′ and lower edge  305  in  FIG.  4    and  FIG.  3   , respectively. In some aspects, face shield  300 ′ can be oriented such that the lower edge  305 ′ can be angled towards the wearer (e.g., pantoscopic tilt). In some aspects, face shield  300 ′ can be oriented such that the lower edge  305 ′ is angled away from the wearer (e.g., retroscopic tilt). 
     With reference to  FIGS.  1 - 2  and  5   , in some aspects, helmet-shield adjustment system  1  can include an adjustment system  200  on either side  101  ( FIG.  1   ) of helmet-shield adjustment system  1 . In some aspects, ends  301  ( FIG.  5   ) of face shield  300  can be adjusted independently using adjustment system  200  on the respective side  101 . In some aspects, ends  301  of face shield  300  can be adjusted simultaneously (e.g., together) using adjustment system  200  on either side  101 . In some aspects, adjustment of ends  301  between a first secured position with a posterior positioning and a second secured position with an anterior positioning can be the same along a plane parallel to AP line  500 , in an inferior-superior direction, and/or with rake adjustment. In some aspects, a frame  250  can be attached to helmet  100  on each side  101  as part of each adjustment system  200 . In some aspects, first and second frames  250  on either side  101  can be the same. For example, a second frame  250  can include a second channel having upper channel  252  and/or lower channel  256 . Accordingly, slider  230  can move within upper channel  252  and/or lower channel  256  of the first frame  250 . Similarly, a second slider  230  can move within upper channel  252  and/or lower channel  256  of the second frame  250 . In this way, slider  230  can move with second slider  230  between a first secured position and a second secured position. Ends  301  of face shield  300  can thus move simultaneously based on the attachment between first and second sliders  230  and face shield  300  (e.g., via outriggers  340  on ends  301 ). 
     Adjustment system  200  can be shown in  FIGS.  6 - 11   , with which helmet-shield adjustment system  1  can be adjusted between a first secured position with a posterior positioning and a second secured position with an anterior positioning along a plane parallel to AP line  500 , (e.g., a direction parallel to tangent line  501 ), and/or with a rake adjustment. 
       FIG.  6    shows a view from the exterior of helmet-shield adjustment system  1 . As shown, in some aspects, lower shell  120  of helmet  100  can be attached to release  270  of adjustment system  200 . In some aspects, release  270  can be attached to upper shell  110  of helmet  100  ( FIG.  1   ). In some aspects, release  270  can be a button or a lever accessible to the wearer from the exterior of helmet-shield adjustment system  1 . Adjustment system  200  and its components can have a rest position  210 . In rest position  210 , slider  230  ( FIG.  2   ) can be in a secured position. In some aspects, release  270  can be coplanar with helmet  100  in rest position  210 . In some aspects, release  270  can be coplanar with a bottom edge  122  of lower shell  120  in rest position  210 , as shown. 
       FIG.  7    shows a view from the exterior of helmet-shield adjustment system  1  with lower shell  120  of helmet  100  removed. As shown, slider  230  can include an upper end  232  and a lower end  234 . Upper end  232  can fit within upper channel  252  of frame  250 . Lower end  234  can fit within lower channel  256  of frame  250 . In some aspects, upper channel  252  can be bounded by a track  254  of frame  250 . Track  254  can contain upper end  232  of slider  230  within upper channel  252  such that upper end  232  moves within upper channel  252 . In some aspects, slider  230  can include a protrusion  233  ( FIG.  9   ) that can move within the channel (e.g., upper channel  252  and/or lower channel  256 ) of frame  250 . In some aspects, track  254  can contain protrusion  233  such that protrusion  233  moves within upper channel  252  and/or lower channel  256  of frame  250 . 
     In some aspects, upper channel  252  and/or lower channel  256  can extend linearly through frame  250 . In some aspects, upper channel  252  and/or lower channel  256  can curve through frame  250 . In some aspects, upper channel  252  and/or lower channel  256  can both extend linearly and curve through frame  250 . In some aspects, slider  230  can move linearly and/or non-linearly within upper channel  252  and/or lower channel  256  while helmet-shield adjustment system  1  is in an as-worn position. in some aspects, slider  230  can rotate within frame  250  while helmet-shield adjustment system  1  is in an as-worn position. 
     In some aspects, slider  230  can also include a spring aperture  236  and a spring  238 . Spring aperture  236  can receive spring  238 . Spring  238  can be supported between spring aperture  236  and frame  250 . In an aspect, spring  238  can bias slider  230 . For example, slider  230  can be biased to extend further into upper channel  252  and/or lower channel  256  of frame  250  via the extension of spring  238 . Accordingly, slider  230  can be biased to extend further into frame  250  such that face shield  300  attached thereto ( FIGS.  1 - 2 , and  5   ) can be similarly biased. Slider  230  in an inward position can position face shield  300  closer to the eyes of the wearer and/or helmet  100  (e.g., D 1  and D 2  in  FIG.  3    relative to D 1 ′ and D 2 ′, respectively, in  FIG.  4   ). As will be described further below, slider  230  can move between a first secured position with a posterior positioning and a second secured position with an anterior positioning ( FIGS.  3 - 4   ). In an aspect, a first secured position with a posterior positioning can coincide with the biased position of slider  230  where slider  230  can extend further into frame  250 . Accordingly, slider  230  can be biased to a first secured position with a posterior positioning. 
       FIG.  8    shows a view from the interior of helmet-shield adjustment system  1  with lower shell  120  of helmet  100  removed. As shown, in some aspects, helmet  100  ( FIG.  1   ) can include a pad  150 . Pad  150  can separate adjustment system  200  from helmet  100 . In some aspects, pad  150  can provide comfort to the wearer. 
     In some aspects, release  270  can include an anchor  272  having a pinned portion  274  and a free end  276 . In some aspects, pinned portion  274  can be attached to release  270 . In an aspect, anchor  272  can be pivotally attached to release  270  at pinned portion  274  such that anchor  272  can rotate about pinned portion  274  relative to release  270 . In some aspects, anchor  272  can be fixed to release  270 . In some aspects, anchor  272  can also include an anchor spring protrusion  278  and a spring  280 . In some aspects, protrusion  278  can extend upward from anchor  272  to support spring  280  between anchor  272  and lower shell  120  ( FIG.  5   ). Accordingly, release  270  can be attached to spring  280  via anchor  272 . This attachment can bias release  270  via the extension of spring  280 . For example, release  270  can be biased such that adjustment system  200  and its components are in rest position  210 . As discussed above with reference to  FIG.  6   , in rest position  210 , release  270  can be coplanar with bottom edge  122  of lower shell  120 . Thus, release  270  can be biased to be coplanar with bottom edge  122  of lower shell  120  in rest position  210 . In rest position  210 , slider  230  can be in a secured position (e.g., a first secured position shown in  FIG.  3    or a second secured position shown in  FIG.  4   ). 
       FIG.  9    shows a view from the interior of helmet-shield adjustment system  1  with lower shell  120  and pad  150  of helmet  100  removed. Additionally, frame  250  is removed. As shown, in some aspects, slider  230  can include a slider member  240 . In some aspects, slider member  240  can have a pinned end  248  and a free end  249 . In some aspects, slider member  240  can have one or more slider teeth  242 . In an aspect, slider teeth  242  can be positioned along a bottom edge  241  of slider member  240 . Accordingly, slider teeth  242  can be part of slider member  240 . In some aspects, slider teeth  242  can be integral with slider  230 . In some aspects, slider member  240  can include a spring aperture  246 . In some aspects, slider member  240  can include a spring  247 . In an aspect, spring aperture  246  can receive spring  247 . Spring  247  can be supported between spring aperture  246  and frame  250 . In some aspects, frame  250  can include a frame member  260 . In some aspects, frame member  260  can be fixed on frame  250 . In some aspects, frame member  260  can have one or more frame teeth  262 . In an aspect, frame teeth  262  can be positioned along top edge  261  of frame member  260 . In some aspects, frame teeth  262  can be integral with frame  250 . 
     In some aspects, slider member  240  can include spring  247  to bias slider member  240 . Slider member  240  can be biased such that slider member  240  can be engaged with frame member  260  via the extension of spring  238 , as shown. Accordingly, slider member  240  can be biased to engage frame member  260 . Frame member  260  can be attached to frame  250  ( FIG.  8   ) to hold slider  230  in a first secured position with a posterior positioning and a second secured position with an anterior positioning ( FIGS.  3 - 4   ). 
     In some aspects, slider member  240  of slider  230  and frame member  260  of frame  250  can engage via slider teeth  242  and frame teeth  262 . The engagement between slider teeth  242  and frame teeth  262  can inhibit translation and/or rotation of slider  230  such that slider  230  can be secured in place. In some aspects, frame member  260  attached to frame  250  ( FIG.  8   ) can engage slider  230  in a first secured position with a posterior positioning and a second secured position with an anterior positioning ( FIGS.  3 - 4   ). In other words, frame teeth  262  can selectively engage slider teeth  242  of slider  230  in a first secured position and a second secured position based on the wearer&#39;s desired positioning. In a first secured position, face shield  300  ( FIGS.  1 - 2  and  5   ), which can be attached to slider  230 , can be fixed in position relative to the eyes of the wearer and/or helmet  100  (e.g., D 1  and D 2  in  FIG.  3    are constant). Accordingly, face shield lens  310  ( FIG.  5   ) of face shield  300  can be fixed in position relative to the eyes of the wearer and/or helmet  100 . Similarly, in a second secured position, face shield  300 ′ can be fixed in position relative to the eyes of the wearer and/or helmet  100  (e.g., D 1 ′ and D 2 ′ in  FIG.  4    are constant). 
     In some aspects, slider  230  and/or frame  250  ( FIG.  8   ) can include a lock (e.g., a latch) to hold slider member  240  in engagement with frame member  260  to prevent spring  247  from compressing and releasing slider teeth  242  of slider member  240  from engagement with frame teeth  262  of frame member  260 . 
     In some aspects, slider member  240  can include between three and ten slider teeth  242 . In some aspects, slider member  240  can include four slider teeth  242 . Each slider tooth  242  can include a front edge  243  and a rear edge  244 . Front edge  243  can be the edge facing pinned end  248  and can be angled relative to a longitudinal axis  5  disposed on a plane coinciding with top edge  261  of frame member  260 . Rear edge  244  can be the edge facing free end  249  and can extend perpendicularly relative to longitudinal axis  5 . In some aspects, frame member  260  can include between five and fifteen frame teeth  262 . In some aspects, frame member  260  can include seven frame teeth  262 . Each frame tooth  262  can include a front edge  263  and a rear edge  264 . Front edge  263  can be the edge farther from release  270  and can extend perpendicularly relative to longitudinal axis  5 . Rear edge  264  can be the edge facing release  270  and can be angled relative to longitudinal axis  5 . In some aspects, rear edge  244  and rear edge  264  can extend at the same angle from longitudinal axis  5 . 
     In some aspects, each slider tooth  242  and frame tooth  262  can have the same width at their respective widest portions. In some aspects, each slider tooth  242  and frame tooth  262  can include a width at their widest portion of approximately two millimeters. In some aspects, each slider tooth  242  and frame tooth  262  can include a height at their tallest portion of approximately one millimeter to approximately two millimeters. In some aspects, the engagement between slider teeth  242  and frame teeth  262  can include rear edge  244  of slider teeth  242  and front edge  263  of frame teeth  262  engaging. Similarly, in some aspects, the engagement between slider teeth  242  and frame teeth  262  can include front edge  243  of slider teeth  242  and rear edge  264  of frame teeth  262  engaging. 
     In some aspects, slider  230  can be attached to a strap that can be fixed to secure slider in place. In some aspects, slider  230  can be attached to a strap that can snap to frame  250  to secure slider  230  in place. In some aspects, one or more snaps can be fixed onto frame  250 . In some aspects, one or more snaps can be fixed onto helmet  100 . In this way, slider  230  can be attached to a strap that can snap to secure slider  230  in one of a plurality of positions. Accordingly, slider  230  can move between a first secured position with a posterior positioning and a second secured position with an anterior positioning ( FIGS.  3 - 4   ). 
     In some aspects, to disengage slider  230  from frame member  260 , slider teeth  242  of slider member  240  can disengage from frame teeth  262  of frame member  260 . Disengaging slider teeth  242  and frame teeth  262  can allow for translation and/or rotation of slider  230  such that slider  230  is not in a secured position. In this way, slider  230  and face shield  300  attached thereto can be moved relative to the eyes of the wearer and/or helmet  100  while in an as-worn position. Additionally, face shield lens  310  ( FIG.  5   ) of face shield  300  can be moved relative to the eyes of the wearer and/or helmet  100 . 
     As shown in  FIG.  9   , in some aspects, pinned end  248  of slider member  240  can be attached to slider  230 . In some aspects, slider member  240  can be pivotally attached to slider  230  at pinned end  248  such that slider member  240  can rotate about pinned end  248  relative to slider  230 . In some aspects, free end  249  can be coupled to release  270 . In some aspects, free end  249  can be coupled to free end  276  of release  270 . Accordingly, as release  270  moves from its biased position, free end  249  of slider member  240  can be moved by free end  276  of release  270 . This movement can compress spring  247  of slider member  240  such that slider member  240  can be moved away from its biased position. In some aspects, moving slider member  240  away from its biased position can disengage slider  230  from frame member  260 . The movement of release  270  can move adjustment system  200  and its components to an actuated position  220 . 
     In some aspects, helmet-shield adjustment system  1  can include a release  270  on either side  101  of helmet-shield adjustment system. In some aspects, a single release  270  can be actuated to release adjustment system  200  on either side  101  of helmet-shield adjustment system  1 . In some aspects, release  270  on either side  101  of helmet-shield adjustment system  1  can be operatively attached (e.g., by a wire) such that actuation of one release  270  can actuate both releases  270 . In this way, adjustment system  200  on either side  101  can be in actuated position  220  by actuating one or more releases  270 . Additionally, actuation of one release  270  can require one hand to operate adjustment system  200 . 
     With reference to  FIGS.  10 - 11   , adjustment system  200  and components thereof can be in actuated position  220 .  FIG.  11    shows a view from the interior of helmet-shield adjustment system  1  with lower shell  120  and pad  150  of helmet  100  removed. Additionally, frame  250  is removed. In actuated position  220 , frame member  260  can be disengaged from slider member  240  to move slider  230  in an as-worn position. Thus, adjustment system  200  can be in actuated position  220  while helmet-shield adjustment system  1  is in engaged position  20 . Accordingly, slider  230  and face shield  300  attached thereto can be moved while helmet  100  and face shield  300  are attached between a first secured position with a posterior positioning and a second secured position with an anterior positioning ( FIGS.  3 - 4   ). Once a desired position is reached, the wearer can return adjustment system  200  to rest position  210  such that release  270  is no longer actuated and frame member  260  and slider  230  can engage to fix slider  230  and face shield  300  attached thereto in a secured position relative to the eyes of the wearer and/or helmet  100 . 
     Release  270  moving from rest position  210  to actuated position  220  can thus disengage frame member  260  from slider  230  to move slider  230  in an as-worn position. In other words, release  270  in actuated position  220  can disengage slider  230  to move face shield  300  between a first secured position with a posterior positioning and a second secured position with an anterior positioning ( FIGS.  3 - 4   ). 
     In some aspects, a distance  239  along longitudinal axis  5  between a first secured position with a posterior positioning and a second secured position with an anterior positioning can be less than a length of frame member  260 . In some aspects, distance  239  can represent the displacement of slider  230 . In some aspects, distance  239  can be within a range of approximately one millimeter to approximately 15 millimeters, such as approximately five millimeters to approximately 10 millimeters, such as approximately seven millimeters. In some aspects, distance  239  can be approximately one millimeter. In some aspects, the displacement of slider  230  can coincide with a displacement of slider member  240  and/or release  270 . In some aspects, the displacement of slider member  240  can be an angle  245  relative to longitudinal axis  5 . In some aspects, angle  245  can be between five degrees and 20 degrees, such as between seven degrees and 15 degrees, such as 10 degrees. In some aspects, the displacement of release  270  can be an angle  275  relative to a longitudinal axis  6  disposed on a plane coinciding with a bottom edge  271  of anchor  272 . In some aspects, angle  275  can be between five degrees and 20 degrees, such as between seven degrees and 15 degrees, such as 10 degrees. 
     As shown in  FIG.  11   , in some aspects, slider  230  can move in a direction  2  from a second secured position with an anterior positioning to a first secured position with a posterior positioning. Similarly, in some aspects, slider  230  can move in a direction  3  from a first secured position with a posterior positioning to a second secured position with an anterior positioning. Accordingly, slider  230  can translate to adjust face shield  300  relative to the eyes of the wearer and/or helmet  100 . In some aspects, slider  230  can rotate to adjust face shield  300  relative to the eyes of the wearer and/or helmet  100 . In some aspects, slider  230  can translate and rotate to adjust face shield  300  relative to the eyes of the wearer and/or helmet  100 . 
     As discussed above, helmet-shield adjustment system  1  can include an adjustment system  200  on either side  101  ( FIG.  1   ). In some aspects, first and second sliders  230  of face shield  300  ( FIGS.  1 - 2   ) can move simultaneously in direction  2  and direction  3  between a first secured position and a second secured position. In some aspects, first and second sliders  230  can rotate to adjust face shield  300  relative to the eyes of the wearer and/or helmet  100 . In some aspects, first and second sliders  230  can translate and rotate to adjust face shield  300  relative to the eyes of the wearer and/or helmet  100 . 
     As shown in  FIG.  12   , helmet-shield adjustment system  1  can be in a detached position  10 . In detached position  10 , face shield  300  can be removed from helmet  100 . 
     In some aspects, helmet  100  can include a shield attachment  160  for attaching and removing face shield  300  between engaged position  20  ( FIG.  10   ) and detached position  10 , respectively. In some aspects, shield attachment  160  can be a magnetic interface that includes one or more magnets  162 . In some aspects, shield attachment  160  can include an upper recess  164  supported by an upper recess rim  165  and an upper recess wall  166 . In some aspects, shield attachment  160  can also include a lower recess  168  supported by a first lower recess wall  170  and a second lower recess wall  172 . In some aspects, upper recess wall  166  can be a round sidewall around upper recess rim  165 . In some aspects, first lower recess wall  170  can extend at an angle  169  from lower recess  168  toward upper recess  164 . In some aspects, second lower recess wall  172  can extend perpendicularly from lower recess  168 . In some aspects, second lower recess wall  172  can also include a protrusion  174  ( FIG.  14   ) that can extend inward into lower recess  168 . In some aspects, magnet  162  can be disposed in each of upper recess  164  and lower recess  168 . 
     With reference to  FIGS.  12 - 13   , helmet-shield adjustment system  1  can move from detached position  10  ( FIG.  12   ) to engaged position  20  ( FIG.  13   ). As shown in  FIG.  12   , face shield  300  can include a helmet attachment  360 . In some aspects, helmet attachment  360  can be a magnetic interface. Helmet attachment  360  can attach to shield attachment  160  to move helmet-shield adjustment system  1  from detached position  10  to engaged position  20 . 
     As shown in  FIG.  14   , in some aspects, helmet attachment  360  can be disposed on outrigger  340  of face shield  300 . In some aspects, helmet attachment  360  can include one or more magnets  362 . In some aspects, helmet attachment  360  can include an upper recess  364  supported by an upper recess wall  366 . In some aspects, helmet attachment  360  can also include a lower recess  368  supported by a first lower recess wall  370  and a second lower recess wall  372 . In some aspects, upper recess wall  366  can be a round sidewall for supporting upper recess  364 . In some aspects, upper recess wall  366  can fit within upper recess  164  of shield attachment  160 . In some aspects, first lower recess wall  370  can extend at an angle  369  from lower recess  368  toward upper recess  364 . In some aspects, second lower recess wall  372  can extend perpendicularly from lower recess  368 . In some aspects, second lower recess wall  372  can also include a protrusion  373  that can extend outward from lower recess  368 . In some aspects, protrusion  373  can be received in second lower recess wall  172  of shield attachment  160  around protrusion  174 , as shown in  FIG.  14   . In some aspects, a magnet  362  can be disposed in each of upper recess  364  and lower recess  368  of helmet attachment  360  to magnetically attach to magnets  162  of shield attachment  160 . 
     Based on the foregoing, in some aspects, magnets  362  disposed in outrigger  340  of face shield  300  can attach face shield  300  to helmet  100 . In some aspects, helmet attachment  360  can also include a release  374 . In some aspects, release  374  can be a button or a lever accessible from outside face shield  300 . In some aspects, release  374  can be biased such that magnet  162  disposed in lower recess  168  and magnet  362  disposed in lower recess  368  are attached. In some aspects, a spring  376  can be supported between upper recess wall  366  and first lower recess wall  370 . In some aspects, spring  376  can bias release  374 . In some aspects, release  374  can extend from second lower recess wall  372  such that actuating release  374  can compress spring  376 . Compressing spring  376  can move release  374  away from its biased position. Moving release  374  attached to lower recess  368  can move lower recess  368  to interrupt the magnetic attachment between magnet  162  disposed in lower recess  168  and magnet  362  disposed in lower recess  368 . Accordingly, the wearer can actuate release  374  to detach magnet  162  disposed in lower recess  168  from magnet  362  disposed in lower recess  368 . In some aspects, the wearer can pull face shield  300  to detach magnet  162  disposed in upper recess  164  from magnet  362  disposed in lower recess  368 . In this way, face shield  300  and helmet  100  can be detached from one another. 
     As shown in  FIG.  15   , helmet-shield adjustment system  1  can be in a stowed position  30 . In some aspects, helmet  100  can include a second shield attachment  160  ( FIGS.  12 - 13   ) for attaching and removing face shield  300  between stowed position  30  and detached position  10 , respectively. Accordingly, helmet  100  can include a first shield attachment  160  to couple helmet  100  to face shield  300  in engaged position  20  ( FIG.  13   ) and a second shield attachment  160  to couple helmet  100  to face shield  300  in stowed position  30 . Stowed position  30  can secure face shield  300  to helmet  100  when not in engaged position  20 . In this way, face shield  300  can be maintained with helmet  100  when not in an as-worn position. 
     As discussed above, in some aspects, face shield  300  and/or face shield  300 ′ and components thereof can be oriented to have a rake or lens tilt ( FIG.  4   ). In some aspects, frame  250  and/or slider  230  (and/or components thereof) can translate and/or rotate to move between a first secured position with a posterior positioning and a second secured position with an anterior positioning to provide a rake adjustment ( FIGS.  3 - 4   ). 
     With reference to  FIGS.  16 - 17   , in some aspects, frame  250  and/or slider  230  (and/or components thereof) can translate or rotate relative to longitudinal axis  5  when release  270  is in actuated position  220  ( FIG.  11   ). In this way, slider  230  and face shield  300  engaged with frame  250  via slider member  240  can be adjusted translationally and rotationally. In some aspects, shield attachment  160  can rotate to adjust face shield  300  rotationally. In some aspects, shield attachment  160  can rotate relative to frame  250 . In some aspects, one or more slots on shield attachment  160  can guide rotation relative to frame  250 . In some aspects, a protrusion moving within slot can fix shield attachment  160  and provide a rake or lens tilt. In some aspects, frame  250  can include a bar  265  extending across lower channel  256 . In some aspects, slider  230  can be attached to frame  250  by receiving bar  265  in a corresponding opening  235 . In some aspects, slider  230  can rotate about bar  265  to adjust rotationally. In some aspects, a rotating tool can be actuated to rotate frame  250 , slider  230 , and/or shield attachment  160 . In some aspects, a rotating tool can translate a top end of face shield  300  to provide a rake or lens tilt. 
     It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present invention as contemplated by the inventors, and thus, are not intended to limit the present invention and the appended claims in any way. 
     The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present invention. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance. 
     The breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.