WO2021055332A1

WO2021055332A1 - Impact-dissipating, fluid-containing helmet liners and helmet liner retainers

Info

Publication number: WO2021055332A1
Application number: PCT/US2020/050836
Authority: WO
Inventors: Jason E. KIRSHON
Original assignee: Impact Technologies, Llc
Priority date: 2019-09-16
Filing date: 2020-09-15
Publication date: 2021-03-25
Also published as: US20210076769A1

Abstract

Impact-dissipating liners (10, 116, 316), helmets (60, 111, 310) having an impact-dissipating liner, helmet liner retainers (114), and methods of protecting the head from impact are provided. The liners (10, 116, 316) include fluid impermeable enclosures (26, 28, 30, 32, 34, 142) having internal cavities, and a fluid (14) contained in the enclosures. The enclosures are in fluid communication via passages comprising a restriction (50) between the internal cavities of the enclosures that may restrict flow of the fluid between the enclosures. The helmet liner retainers (114) include a head strap (118) and at least one projection (124, 126, 128, 130) extending from the head strap sized to engage at least one recess (134, 136, 138, 140) in a headgear liner to retain the headgear liner. Though applicable to a broad range of protective headgear, the liners and liner retainers disclosed are uniquely adapted for use in construction helmets, that is, "hard hats."

Description

IMPACT-DISSIPATING, FLUID-CONTAINING HELMET LINERS AND

HELMET LINER RETAINERS

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority from pending U.S. Provisional Patent Application 62/900,967 filed on September 16, 2019; U.S. Provisional Patent Application 62/945,529 filed on December 9, 2019; and U.S. Provisional Patent Application 63/036,006 filed on June 8, 2020, the disclosures of which are included by reference herein in their entirety.

[0002] This application is also related to pending US application 15/833,747, filed on December 6, 2017, now US Patent 10,531,699 issued on January 14, 2020; is related to US application 16/738,234 filed on January 9, 2020, and is related to US application 16/595,135 filed on October 7, 2019, the disclosures of which are included by reference herein in their entirety.

BACKGROUND OF THE INVENTION

Technical Field

[0003] Aspects of the present invention relate generally to protective headgear, such as, helmets, and the minimization and prevention of head injury. More particularly, aspects of the invention, in their several embodiments, provide helmets, headgear, helmet liner retainers, helmet assemblies having fluid filled protective liners, and methods of protecting the head. Aspects of the invention may be particularly adapted for use in protective construction helmets, for example, “hard hats,” as known in the art. Description of Related Art

[0004] Numerous human activities, such as, recreation and sports, construction, public protection, and armed service, expose the human body, especially, the head, to impact and injury.

[0005] Head injury can be the most traumatic type of bodily injury. Especially when in motion, the exposure of the human head to contact and injury can be a continuous concern, whether the motion is while in a motorized vehicle or a bicycle or walking beneath an active building site. Many attempts have been made in the art of head protection to minimize damage to the skull, brain, and brain stem due to head impact.

[0006] Many prior art attempts to address this concern have yielded various helmet designs that provide impact energy absorbing materials, for example, foam rubbers and plastics, in an attempt to provide as much “cushioning” material between the surface of impact and the head. Accordingly, in the state of the helmet art in the early 21^st century, it is typical to provide as much foam cushioning within a helmet without detracting from the aesthetic appearance of the helmet. The resulting helmets have been limited in their success in meeting either goals of head protection or aesthetics.

[0007] Among other things, as the amount of cushioning material, for example, plastic foam, increases, the larger the envelope and the greater the exposure of the resulting helmet. Specifically, though a larger volume of cushioning material within a helmet may absorb more impact energy, and lessen the amount of impact energy transmitted to the head, the larger volume also increases the torsional movement arm between the point of contact and, for example, the neck, brain stem, and spinal cord of the helmet wearer. Accordingly, providing impact protection while minimizing torsional loading on the wearer is desirable.

[0008] Though of relatively minor consequence to some users, the larger the amount of cushioning material typically also results in a more unsightly appearance of the resulting helmet to the typical helmet wearer. Accordingly, there is a need in the art to ensure proper head protection, while, it is preferred, providing an aesthetically appealing helmet.

[0009] Though many forms of activity can expose the head to impact loading, athletic completion or contact sports can be one of the more acute concerns for helmet design and head protection. It is well recognized that the repeated contact of the head in such contact sports as football, hockey, and soccer expose the athlete, even though protected with some form of headgear, to degenerative brain damage. The occurrence of chronic traumatic encephalopathy (CTE) in professional athletes, especially in former professional football and hockey players, is well documented. It is generally believed that the repeated exposure of the head to impact loading, even when protected, can result in deteriorating and life changing effects upon cognitive abilities and behavior. Efforts continue to be made to investigate the cause of CTE and to mitigate or prevent its occurrence. Accordingly, there is need in the art to provide more protective headgear for athletes.

[0010] The “hard hat” is one of the oldest and most widely used head protection devices. The hard hat in its many manifestations is a common feature of many activities, commercial and non-commercial, where the human head may be exposed to potential injury from, among other things, falling objects. Though the common hard hat design having a projective helmet shell and suspension providing an interface between the helmet shell and the head of the wearer can be very effective, due to the critical effect of potential head injury to workers and others, there continues to be a need in the art for enhancing hard hat design and construction.

[0011] In addition, when the situation and/ or head clearance discourage the use of a conventional hard hat, the smaller and, typically, less obtrusive “bump cap” may be worn to provide at least some impact protection, for example, in tight quarters. As known in the art, bump caps may have the appearance and envelope of a conventional baseball cap, but can provide some form of internal liner and/ or suspension providing head protection not typically provided by conventional baseball caps or similar headgear.

[0012] U.S. Patent 8,856,972 of Kirshon first introduced the concept of liquid- filled, fluid-displaced liner technology to the art. This technology is marketed by KIRSH Helmets of Schenectady, New York under the trademarks Fluid Displacement Liner™ technology or FDL™ technology. Though the inventions disclosed in the ‘972 patent provide an effective means for dissipating impact loading, further improvements and advantages are provided by the present inventions.

[0013] Aspects of the present invention provide protective impact-dissipating liners, for example, headgear, methods of minimizing the transfer of impact loads upon the human head that overcome the limitations and disadvantages of the prior art.

SUMMARY OF THE INVENTION

[0014] Embodiments of the present invention, in their many aspects, provide protective impact-dissipating liners, for example, for headgear, methods of minimizing the transfer of impact loads upon the human head, methods of fabricating such impact-dissipating liners, and protective retaining devices and arrangements for impact-dissipating liners, for example, retaining devices and arrangements for headgear, such as, hard hats, bump caps, or other headgear, that minimize the transfer of impact loads to the head of a user.

[0015] One embodiment of the invention is an impact dissipating helmet liner comprising or including: a plurality of flexible, fluid impermeable enclosures, each of the enclosures having opposing end walls, a sidewall extending between the opposing end walls; and a fluid contained in each of the plurality of enclosures; wherein each of plurality of flexible, fluid impermeable enclosures is in fluid communication with at least one of the other enclosures via a passage comprising a restriction between the enclosures. In one aspect, the liner may further comprise a plurality of cavities extending between the upper wall and the lower wall of each of the plurality of enclosures. In another aspect, the liner may further comprise a cavity sidewall extending from the upper wall to the lower wall of each of the plurality of cavities.

[0016] In one aspect, the restriction may at least partially restrict flow of the fluid between the enclosures. In one aspect, the restriction may have a width less than a width of the enclosures. In another aspect, the restriction may have a width less than 3 times a height of the restriction.

[0017] In another aspect each of the plurality of flexible, fluid impermeable enclosures maybe cylindrical, for example, circular cylindrical. In one aspect, one of the plurality of flexible, fluid impermeable enclosures may include a central enclosure and at least one of the plurality of the flexible, fluid impermeable enclosures may include at least one peripheral enclosure in fluid communication with the central enclosure via the passage having the restriction. In one aspect, the at least one peripheral enclosure may comprise a plurality of radially extending enclosures from the central enclosure. The plurality of radially extending enclosures may have divergent sidewalls

[0018] In one aspect, the fluid may be a liquid, for example, a liquid polydimethylsiloxane or water. The liquid polydimethylsiloxane may be a CHT QM Diluent, for example, a CHT QM Diluent having a viscosity ranging from 50 to 5000 centipoise (cps.)

[0019] In one aspect, the plurality of flexible, fluid impermeable enclosures, may comprise a synthetic amorphous silica, for example, a CHT True Skin® synthetic amorphous silica.

[0020] The present invention also provides improved headgear suspensions that accommodate the latest improvements in impact diffusing, fluid-filled headgear liner technology. These headgear suspensions include projections that engage recesses in fluid-filled liners that at least partially retain, preferably, securely retain, fluid filled liners, among others, into headgear, such as, hard hats.

[0021] One embodiment of the invention is a headgear liner retainer comprising or including: a head strap adapted to engage the head of a user and mount to a headgear; and at least one projection extending from the head strap, the at least one projection positioned and sized to engage at least one recess in a headgear liner; wherein the engagement of the at least one projection with the at least one recess in the headgear at least partially retains the headgear liner in the headgear. In one aspect, the at least one projection may comprise plurality of projections, for example, cylindrical projections, each of the plurality of projections positioned and sized to engage at least one recess in a headgear liner. In another aspect, the at least one recess in the headgear liner may comprise a least one cylindrical recess, and wherein each of the plurality of cylindrical projections are sized to engage the least one cylindrical recess.

[0022] In one aspect, the headgear liner may comprise a fluid-filled headgear liner and wherein the at least one recess in the fluid-filled headgear liner may comprise at least one cavity in the fluid-filled headgear liner. In one aspect, the at least one cavity in the fluid-filled headgear liner may comprise at least one through hole in the fluid-filled headgear liner. In another aspect, the at least one projection extending from the head strap may comprise at least one projection extending radially inward or radially outward from the strap.

[0023] Another embodiment of the invention is a helmet liner assembly comprising or including a helmet liner comprising a flexible, fluid impermeable enclosure having opposing end walls, a sidewall extending between the opposing end walls, a fluid contained in the enclosure, and at least one recess in the flexible, fluid impermeable enclosure; and a helmet liner retainer comprising a head strap adapted to engage the head of a user and mount to a headgear, and at least one projection extending from the head strap, the at least one projection positioned and sized to engage the at least one recess in the flexible, fluid impermeable enclosure of the helmet liner; wherein the engagement of the at least one projection with the at least one recess in the headgear at least partially retains, for example, securely retains, the headgear liner in the headgear. In one aspect, the at least one projection may comprise a plurality of projections, each of the plurality of projections positioned and sized to engage at least one recess in the helmet liner. In one aspect, the at least one projection extending from the head strap may comprise a plurality of cylindrical projections extending from the head strap, for example, wherein the at least one recess in the helmet liner may comprise at least one cylindrical recess, and wherein each of the plurality of cylindrical projections are sized to engage the at least one cylindrical recess.

[0024] In one aspect, the at least one recess in the flexible, fluid impermeable enclosure may comprise at least one cavity in the flexible, fluid impermeable enclosure, for example, at least one through hole in the flexible, fluid impermeable enclosure. In one aspect, the helmet liner may comprise a plurality of flexible, fluid impermeable enclosures, and wherein the at least one recess comprises at least one recess in each of the plurality of flexible, fluid impermeable enclosures. In another aspect, the at least one projection extending from the head strap may comprise at least one projection extending radially inward or radially outward from the strap.

[0025] Another embodiment comprises or includes a helmet having the headgear liner disclosed herein, or a helmet having the helmet liner assembly disclosed herein, for example, a construction helmet, a hard hat, or a bump cap.

[0026] A further embodiment of the invention is a method of protecting the head, the method comprising or including: mounting a helmet liner retainer comprising a head strap adapted to engage the head of a user and at least one projection extending from the head strap into a helmet shell or bump cap; attaching a helmet liner comprising a flexible, fluid impermeable enclosure containing a fluid and having at least one recess in enclosure to the helmet liner retainer by inserting the at least one projection from the head strap of the helmet liner retainer into the at least one recess in the enclosure; and positioning the helmet with helmet liner retainer and the flexible, fluid impermeable enclosure onto the head of the user.

[0027] Another embodiment of the invention is a helmet or a bump cap having any one of the liners disclosed herein. For example, the helmet may have a helmet shell containing any one of the liners disclosed herein.

[0028] A further embodiment of the invention is a helmet or headgear assembly comprising or including: a helmet shell or a bump cap shaped to generally conform to the head of a wearer, the helmet shell or bump cap having an external surface and an internal surface; a headgear liner shaped and adapted to be received by the helmet or the bump cap, the headgear liner having an external surface positioned to contact the internal surface of the helmet or the bump cap; and at least one interface element positioned between the external surface of the headgear liner and the internal surface of the helmet shell or the bump cap, the at least one interface element providing at least some reduction in friction between the external surface of the headgear liner and the internal surface of the helmet shell or the bump cap.

[0029] In one aspect, the at least one interface element may be a plurality of interface elements mounted to the internal surface of the helmet shell or the bump cap and/ or to the external surface of the headgear liner. In one aspect, the at least one interface element may be a flexible material mounted to the external surface of the headgear liner by an adhesive, a mechanical fastener, or stitching. In one aspect, the headgear liner may be a flexible, fluid impermeable enclosure having opposing end walls, a sidewall extending between the opposing end walls, and a fluid contained in the enclosure.

[0030] In one aspect, the at least one interface element may be a hook-and- loop-type fastener, for example, a hook-and-loop-type fastener mounted to the external surface of the headgear liner. In one aspect, the at least one interface element may be two opposing loop sides of hook-and-loop-type fasteners.

[0031] Another embodiment of the invention is a headgear liner assembly comprising or including: a headgear liner comprising a flexible, fluid impermeable enclosure having opposing end walls, external surfaces on the opposing end walls, a sidewall extending between the opposing end walls, and a fluid contained in the enclosure; and at least one interface element mounted to the headgear liner, the at least one interface element providing at least some reduction in friction between the headgear liner and an internal surface of a helmet shell or a bump cap into which the headgear liner is positioned.

[0032] In one aspect, the at least one interface element on the headgear line may be a hook-and-loop-type fastener mounted to the external surface of the headgear liner. For example, the at least one interface element maybe two opposing loop sides of a hook-and-loop-type fasteners.

[0033] Another embodiment of the invention is a helmet or a bump cap having the headgear liner described above.

[0034] A further embodiment of the invention is a method of protecting the head, the method comprising or including: mounting at least one interface element to an external surface of a headgear liner or an internal surface of a helmet shell or a bump cap, the at least one interface element providing at least some reduction in friction between the external surface of the headgear liner and the internal surface of the helmet shell or the bump cap; inserting the headgear liner into the helmet shell where the at least one interface element is positioned between the external surface of the headgear liner and the internal surface of the helmet shell or the bump cap; and positioning the helmet shell or the bump cap with headgear liner and the at least one interface element onto the head of a user. [0035] These and other aspects, features, and advantages of this invention will become apparent from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention will be readily understood from the following detailed description of aspects of the invention taken in conjunction with the accompanying drawings in which:

[0037] FIGURE l is a perspective view of a helmet liner according to an aspect of the invention.

[0038] FIGURE 2 is a top plan view of the helmet liner shown in FIGURE l.

[0039] FIGURE 3 is a bottom plan view of the helmet liner shown in FIGURE l.

[0040] FIGURE 4 is a perspective view of a detail of the helmet liner shown in FIGURE 1.

[0041] FIGURE 5 is a schematic illustration of a cross section of an interface between enclosures as identified by Section lines 5-5 shown in FIGURE 2 according to one aspect of the invention.

[0042] FIGURE 6 is a perspective view of a helmet assembly that may be used for a liner according to an aspect of the invention.

[0043] FIGURE 7 is a top plan view of the helmet assembly shown in FIGURE 6.

[0044] FIGURE 8 is a top plan view of the helmet assembly shown in FIGURE 7 having a headgear liner according to one aspect of the invention. [0045] FIGURES 9 through 13 are schematic top plan views of headgear liners according to other aspects of the invention.

[0046] FIGURE 14 is a bottom perspective view of a helmet assembly according to one aspect of the invention.

[0047] FIGURE 15 is a perspective view of the helmet assembly shown in FIGURE 14 flipped over.

[0048] FIGURE 16 is an exploded perspective view of the helmet assembly shown in FIGURE 15.

[0049] FIGURE 17 is a bottom perspective view of the engaged helmet suspension and headgear liner shown in FIGURE 16.

[0050] FIGURE 18 is a top perspective view of the engaged helmet suspension and headgear liner shown in FIGURE 17.

[0051] FIGURE 19 is a bottom plan view of the engaged helmet suspension and headgear liner shown in FIGURE 18.

[0052] FIGURE 20 is a front elevation view of the engaged helmet suspension and headgear liner shown in FIGURE 19.

[0053] FIGURE 21 is a rear elevation view of the engaged helmet suspension and headgear liner shown in FIGURE 20.

[0054] FIGURE 22 is a side elevation view of the engaged helmet suspension and headgear liner shown in FIGURE 21.

[0055] FIGURES 23A and 23B are detailed perspective views of the engagement of the projections shown in FIGURE 16 before and after engagement, respectively, according to one aspect of the invention. [0056] FIGURES 24A and 24B are detailed perspective views of the engagement of a projection shown in FIGURES 23A and 23B before and after engagement, respectively, according to one aspect of the invention.

[0057] FIGURES 25A and 25B are detailed perspective views of the engagement of a projection shown in FIGURES 23A and 23B before and after engagement, respectively, according to an aspect of the invention.

[0058] FIGURES 26A, 26B, and 26C are detailed perspective views of the sequential engagement of a projection shown in FIGURES 23A and 23B according to an aspect of the invention.

[0059] FIGURES 27A, 27B, and 27C are detailed perspective views of the sequential engagement of a projection shown in FIGURES 23A and 23B according to an aspect of the invention.

[0060] FIGURES 28A and 28B are detailed perspective views of the sequential engagement of a projection shown in FIGURES 23A and 23B according to an aspect of the invention.

[0061] FIGURES 29A and 29B are detailed perspective views of the sequential engagement of a projection shown in FIGURES 23A and 23B according to an aspect of the invention.

[0062] FIGURE 30 is a perspective view of an arrangement for mounting a liner to a helmet suspension according to another aspect of the invention.

[0063] FIGURE 31 is a detailed perspective view of the arrangement for mounting a liner to a helmet suspension shown in FIGURE 30.

[0064] FIGURE 32 is a top perspective view of a helmet or headgear assembly according to another aspect of the invention. [0065] FIGURE 33 is an exploded perspective view of the helmet or headgear assembly shown in FIGURE 32.

[0066] FIGURE 34 is an exploded perspective view of the headgear liner assembly shown in FIGURE 33.

[0067] FIGURE 35 is a plan view of one interface element shown in FIGURE 34 according to one aspect of the invention.

[0068] FIGURE 36 is a side elevation view of the interface element shown in FIGURE 35.

DETAILED DESCRIPTION OF THE INVENTION

[0069] FIGURE 1 is a perspective view of a helmet or headgear liner 10 according to an embodiment of the invention. FIGURE 2 is a top plan view of the helmet liner 10 shown in FIGURE 1 and FIGURE 3 is a bottom plan view of the helmet liner 10 shown in FIGURE 1. FIGURE 4 is a perspective view of a detail of the helmet liner 10 shown in FIGURE 1.

[0070] As shown in FIGURES 1 through 4, liner 10 comprises an enclosure 12 having a fluid 14 encased within enclosure 12. Fluid 14 may be a liquid or a gas.

In one aspect, enclosure 12 of liner 10 may comprise a liquid silicone rubber (LSR), for example, a cured LSR. In one aspect, enclosure 12 maybe comprise a “medical grade” LSR, as known in the art. In one aspect, enclosure 12 of liner 10 may comprise a liquid silicone rubber marketed by CHT USA (formerly Quantum Silicones (QSi)) under the trademark True Skin® or its equivalent; however, enclosure 12 may comprises any liquid silicone rubber (LSR).

[0071] In one aspect, the fluid 14 encased in enclosure 12 may comprise a polydimethylsiloxane fluid (also know as a “silicone fluid), for example, a polydimethylsiloxane fluid marketed by CHT USA as a QM Diluent or its equivalent; however, liquid 14 may comprise any polydimethylsiloxane fluid. As known in the art, polydimethylsiloxane comprises a group of polymeric organosilicon compounds that are commonly referred to as “silicones.” Polydimethylsiloxane maybe abbreviated “PDMS’ and has the chemical formula [(CH₃)₂SiO]_n. However, in other aspects, liquid 14 maybe any fluid, including an oil or water, such as, distilled water.

[0072] According to aspects of the invention, enclosure 12 of liner 10 may take any conventional size and shape, for example, depending upon the size and/or shape of the helmet or headgear in which liner 10 is used with, for example, a construction helmet, as shown un FIGURES 6 through 8, or a bump cap.

[0073] According to aspects of the invention, as shown in FIGURES 1 through 4, enclosure 12 of liner 10 may comprise a plurality of interconnected enclosures or components, for example, sub-enclosures. For example, enclosure 12 may comprise a multi-enclosure cylindrical shape or a multi-component cylindrical shape. As shown in FIGURES 1 through 4, in one aspect, enclosure 12 may comprise a plurality of interconnected right circular cylindrical enclosures or components 26, 28, 30, 32, and 34 having fluid 14. As shown in FIGURES 1 through 4, in one aspect, liner 10 may comprise five circular cylindrical enclosures or components 26, 28, 30, 32, and 34 having fluid 14. However, it is envisioned that aspects of the invention may have 2 or more interconnected enclosures or components 26, 28, 30, 32, and 34.

[0074] In one aspect, as shown in FIGURES 1 through 4, at least some of components 26, 28, 30, 32, and 34, but typically all of components 26, 28, 30, 32, and 34, may be in fluid communication with at least one of the other components 26, 28, 30, 32, and 34. However, in other aspects, at least one of the 2 or more interconnected components 76, 78, 80, 82, and 84, for example, all of the interconnected components 26, 28, 30, 32, and 34, may not be in fluid communication but may be in fluid isolation from each other. For example, in one aspect, one or more of the enclosures or components 26, 28, 30, 32, and 34 may contain a different fluid, for example, a different QM Diluent or an entirely different fluid.

[0075] As shown in FIGURES l through 4, enclosures or components 26, 28,

30, 32, and 34 of enclosure 12 of liner 10 may comprise any enclosures having an internal cavity 15 containing fluid 14. According to aspects of the invention, components 26, 28, 30, 32, and 34 of enclosure 12 maybe fluid-impermeable, for example, at least impermeable to the passage of fluid 14, for example, liquid impermeable. As shown in FIGURES 1 through 4, components 26, 28, 30, 32, and 34 of enclosure 12 may typically have opposing end walls 16 and 18 (for example, a top and a bottom, respectively) and at least one sidewall 20. End walls 16 and 18 (and any end walls disclosed herein) may have a thickness, for example, a common thickness (though the thickness of the end walls 16 and 18 may vary) and sidewall 20 (and any sidewall disclosed herein) may have a thickness. The thicknesses of end walls 16 and 18 and sidewall 20 maybe equal or may vary, and may typically range from about 0.05 inches to about 0.25 inches, for example, between about 0.10 inches to about 0.12 inches.

[0076] In one aspect of the invention, the internal cavities 15 of enclosures or components 26, 28, 30, 32, and 34 of enclosure 12 of liner 10 maybe devoid of any structure or obstruction. However, in another aspect of the invention, the internal cavities 15 may comprise one or more supports or structures positioned and adapted to influence fluid flow and/ or to retain the shape, among other things, of components 26, 28, 30, 32, and 34 of liner 10, for example, preventing deflection of end walls 16 or 18 and or the deflection of sidewalls 20.

[0077] As shown in phantom in FIGURES 1 through 4, enclosures or components 26, 28, 30, 32, and 34 of liner 10 may include one or more structures, for example, pins, rods, or supports 38 adapted to engage opposing end walls 16 and 18 and, for example, influence fluid flow and/ or prevent portions of end walls 16 or 18 from deflecting, for example, under the force of gravity or the force of the pressure of fluid 14. As shown in FIGURES 1 through 4, in one aspect, supports 38 may be cylindrical in shape, for example, circular cylindrical, though any non-circular cylindrical shape may be used. In one aspect, supports 38 maybe hollow, as indicated by internal cavities 40; however, one or more of supports 38 maybe hollow in one aspect. According to one aspect of the invention, providing hollow supports 38 is envisioned to provide enhanced flexibility to supports 38 where the flexibility of the sidewalls of hollow supports 38 may provide an enhanced capability to absorb, and thus dissipate, the energy of an impact upon liner 10. In one aspect, hollow supports 38 may penetrate end walls 16 and 18 or be in fluid communication with through holes in end walls 16 and 18, for example, where open passages are provided though liner 10 via hollow supports 38. Supports 38 maybe mounted by an adhesive in cavity 15 of enclosure 14 or maybe molded into end walls 16 and 18 of enclosure 12.

[0078] As shown in FIGURES 1 through 4, in one aspect, each of the enclosures or components 26, 28, 30, 32, and 34 of liner 10 maybe connected to at least one of the other components 26, 28, 30, 32, and 34 by an interface, transition, extension, or projection 36 between components 26, 28, 30, 32, and 34. According to aspects of the invention, interface, transition, extension, or projection 36 maybe hollow, for example, allowing fluid communication between components; or solid, for example, preventing fluid communication between components.

[0079] As also shown in FIGURES 1 through 4, in one aspect, at least one of the enclosures or components 26, 28, 30, 32, and 34 of liner 10 may include a region of greater thickness or a boss 42, for example, a boss 42 centrally located upon the surface of end wall 16 of one or more of the components 26, 28, 30, 32, and 34. One or more bosses 42 may be provided to enhance the structural integrity of liner 10 or to introduce variable elasticity to the surface of end wall 16. The thickness of boss 42 maybe from 0.010 to 0.25 inches above the surface of end wall 16 of components 26, 28, 30, 32, and 34, but may typically be about 0.125 inches above the surface of components 26, 28, 30, 32, and 34. [0080] In one aspect, as shown most clearly in the bottom view of liner 10 shown in FIGURE 3, bosses 42 maybe omitted. For example, in one aspect, the bottom surface of liner 10, for example, the surface intended to contact the inner surface of a liner retainer or the inner surface of a helmet shell, may be devoid of any bosses 42 in order to, for example, enhance contact with the contacted surface.

[0081] In one aspect, as shown in FIGURES 1 through 4, the sidewalls 20 of enclosures or components 26, 28, 30, 32, and 34 of liner 10 may include cavities or recesses 46. Recesses 46 maybe provided for aesthetic appearance, to enhance formability or moldability, and/ or to enhance the engagement of liner 10 within any enclosure or retainer into which liner 10 is inserted, among other benefits of cavities 46.

[0082] As shown in FIGURES 1 through 4, liner 10 may comprise multiple enclosures or components 26, 28, 30, 32, and 34 arranged in a somewhat uniform radial pattern. However, it is envisioned that, according to aspects of the invention, liner 10 may take many varying arrangements of enclosures or components and/or enclosures or component shapes, such as, polygonal cylindrical in shape, for example, rectangular cylindrical in shape or square cylindrical in shape, pentagonal cylindrical in shape, or hexagonal cylindrical in shape, among other cylindrical shapes. Other shapes for enclosure 12 are also envisioned, for example, as shown schematically in FIGURES 9 through 13.

[0083] According to one aspect of the invention, at least two, but typically each, of the plurality of flexible, fluid impermeable enclosures or components 26, 28, 30, 32, and 34 maybe in fluid communication with at least one of the other enclosures 26, 28, 30, 32, and 34 via a passage between the enclosures 26, 28, 30, 32, and 34. In one aspect, these one or more passages may comprise one or more restrictions, for example, a path of reduced cross-sectional area that in some way limits the flow of fluid between one or more of enclosures 26, 28, 30, 32, and 34. FIGURE 5 is a schematic illustration of a cross section of an interface 36 between enclosures as identified by Section lines 5-5 shown in FIGURE 2 illustrating a passage comprising a restriction according to one aspect of the invention.

[0084] As shown in FIGURE 5, the cross section of the interface 36 between any two of enclosures 26, 28, 30, 32, and 34 may comprise a restriction or flow cross- section of reduced area 50 between adjoining enclosures. FIGURE 5 illustrates a restriction 50 between enclosures 26 and 34, though restriction 50 maybe typical of a restriction between any two enclosures or components 26, 28, 30, 32, and 34 or any other enclosure or component disclosed herein. According to this aspect of the invention, restriction 50 may comprise a fluid passage of reduced open cross-sectional area between enclosures that provides at least some restriction or resistance to fluid flow, for example, uniform fluid flow, between adjoining enclosures. Typically, a restriction such as restriction 50 results in at least some resistance to flow, sometimes referred to as pressure drop or a “back pressure,” and at least a local acceleration in fluid flow, for example, a local increase in fluid velocity through the restriction 50. However, in another aspect of the invention, the flow through one or more areas 50 may not be restricted or limited, for example, fluid may be allowed to flow through area 50 with little or no pressure drop.

[0085] In the aspect of the invention shown in FIGURE 5, restriction 50 is illustrated as rectangular in cross section; however, according to aspects of the invention, restriction 50 may take any cross sectional shape while providing the restriction to flow disclosed herein. For example, restriction 50 maybe circular, elliptical, or polygonal in cross section while providing the restriction to flow function provided herein.

[0086] In one aspect of the invention, the size of restriction 50 may be related to the width of the enclosure or component 26, 28, 30, 32, or 34. For example, in one aspect, the internal width, w, of restriction 50 may be related to the width, W, of the enclosure or component 26, 28, 30, 32, or 34, for example, a maximum width, W_max, of the enclosure or component 26, 28, 30, 32, or 34. In one aspect, assuming a common internal height, h, of the enclosure 26, 28, 30, 32, or 34 and the restriction 50, restriction 50 may have a width, w, of at most about 50% of the width, W, of the component, or at most 40% of the width W, or at most 30% of the width W, or at most 20% of the width W, or at most 10% of the width W.

[0087] In another aspect, the dimension of restriction 50 may be defined by an aspect ratio (AR) between the width, w, and the height, h, of restriction 50, that is, AR = w/h. For example, in one aspect, the aspect ration of restriction 50 may be greater than or equal to 0.50 and less than or equal to 10. In another aspect, the aspect ration of restriction 50 maybe greater than or equal to 1 and less than or equal to 6. In another aspect, the aspect ration of restriction 50 maybe greater than or equal to 2 and less than or equal to 4.

[0088] In one aspect, as shown most clearly in FIGURE 2, the interface, transition, extension, or projection 36 between components 26, 28, 30, 32, and 34 maybe devoid of any obstructions, such as, supports 38, and/or devoid of any through holes, such as, holes 40.

[0089] FIGURE 6 is a perspective view of a helmet assembly 60 that may be used for a liner 10 according to an aspect of the invention. FIGURE 7 is a top plan view of the helmet assembly 60 shown in FIGURE 6. As shown in FIGURES 6 and 7, helmet assembly 60 may typically include a helmet shell 62, for example, a construction helmet shell, a liner retainer or interface 64, and a helmet suspension or harness 66 mounted in helmet shell 62. As known in the art, helmet suspension 66 is adapted to engage the head of the wearer of the helmet, and maybe adjustable, for example, to snuggly fit the helmet to the head of the wearer. As shown in FIGURES 6 and 7, in one aspect, helmet assembly 60 may also include a helmet chinstrap 68, as is typical in the art. Though FIGURES 6, 7, and 8 illustrate aspects of the invention as they apply to hard hats having a helmet shell, it is envisioned that aspects of the invention, that is, liners and liner retainers, may be applied to any headgear, that is, any headgear which could be enhanced by employing aspects of the invention. This includes bump caps and related headgear and any one the helmets or headgear disclosed herein.

[0090] According to one aspect of the invention, liner retainer or interface 64 includes one or more recesses 70 positioned and sized to receive a liner according to aspects of the invention, for example, liner 10 shown in FIGURES 1-4. In the aspects shown in FIGURES 6 and 7, recesses 70 comprise circular recesses adapted to receive the circular cylindrical enclosures 26, 28, 30, 32, and 34 of liner 10. However, according to aspects of the invention, recesses 70 maybe non circular, for example, elliptical, rectangular, or polygonal, and be adapted to receive similarly shaped enclosures or components of a liner.

[0091] FIGURE 8 is a top plan view of helmet assembly 60 shown in FIGURE 7 having liner 10 according to one aspect of the invention. As shown in FIGURE 8, recesses 70 of liner retainer or interface 64 of helmet assembly 60 may receive enclosures 26, 28, 30, 32, and 34 of liner 10 without any additional retaining means, for example, recesses 70 maybe sized and shaped to snugly receive enclosures 26, 28, 30, 32, and 34 of liner 10, for example, due to the flexibility or compressibility of liner 10, and be retained by friction where no additional retaining device or mechanism maybe provided. In other aspects, enclosures 26, 28, 30, 32, and 34 of liner 10 maybe retained in recesses 70 by a retaining device or mechanism, for example, with hardware, straps, and/ or an adhesive.

[0092] FIGURE 9 is a schematic top plan view of a liner 100 that may have one or more of the attributes of liner 10 according to another aspect of the invention. As shown, liner 100 may comprise two or more enclosures 26, 28, 30, 32, and 34 of liner 10 shown in FIGURES 1 through 4. In one aspect, liner 100 maybe mounted in a helmet with a liner retainer 64 as shown and described with respect to FIGURES 6 through 8.

[0093] FIGURE 10 is a schematic top plan view of a liner 102 that may have one or more of the attributes of liner 10 according to another aspect of the invention. As shown, liner 102 may comprise three or more enclosures 26, 28, 30, 32, and 34 of liner 10 shown in FIGURES 1 through 4. In one aspect, liner 102 maybe mounted in a helmet with a liner retainer 64 as shown and described with respect to FIGURES 6 through 8.

[0094] FIGURE 11 is a schematic top plan view of a liner 104 that may have one or more of the attributes of liner 10 according to another aspect of the invention. As shown, liner 104 may comprise four or more enclosures 26, 28, 30, 32, and 34 of liner 10 shown in FIGURES 1 through 4. In one aspect, liner 104 maybe mounted in a helmet with a liner retainer 64 as shown and described with respect to FIGURES 6 through 8.

[0095] FIGURE 12 is a schematic top plan view of a liner 106 that may have one or more of the attributes of liner 10 according to another aspect of the invention. As shown, liner 106 may comprise five or more enclosures 26, 28, 30, 32, and 34 of liner 10 shown in FIGURES 1 through 4. In one aspect, liner 106 maybe mounted in a helmet with a liner retainer 64 as shown and described with respect to FIGURES 6 through 8

[0096] FIGURE 13 is a schematic top plan view of a liner 108 that may have one or more of the attributes of liner 10 according to another aspect of the invention. As shown, liner 108 may comprise two or more circular cylindrical enclosures 26, 28, 30, 32, and 34 of liner 10 shown in FIGURES 1 through 4 and one or more rectangular, square, or polygonal cylindrical enclosures no, for example, a centrally mounted enclosure 110. In one aspect, liner 108 maybe mounted in a helmet with a liner retainer 64 as shown and described with respect to FIGURES 6 through 8.

[0097] According to aspects of the invention, the enclosures of the liners disclosed herein, for example, liners 10, 100, 102, 104, 106, and 108, may comprise any flexible, fluid-impermeable material, for example an elastomer. In one aspect, the material of any one of the liners disclosed herein maybe a natural polymer, such as, polyisoprene rubber, or a synthetic polymer, such as, a neoprene, a thermoplastic elastomer, a thermoplastic rubber, and a polyvinyl chloride, or an ethylene propylene diene monomer (EPDM) rubber, and the like.

[0098] According to one aspect of the invention, the enclosures of the liners disclosed herein, for example, liners 10, 100, 102, 104, 106, and 108, may comprise a liquid silicone rubber, for example, a cured liquid silicone rubber, such as, a platinum-cured LSR. In one aspect, the enclosures of the liners disclosed herein may comprise a LSR marketed under the trademark True Skin ®; however, the enclosures of the liners disclosed herein may comprise any cured liquid silicone rubber (LSR). In one aspect, the cured liquid silicone rubber may be a “medical grade” LSR, as known in the art, for example, an LSR having an elasticity, a viscosity, a “feel,” and/or anti-microbial properties, among other things, that are desirable in aspects of the invention.

[0099] However, in one aspect, a liquid silicone rubber marketed under the trademark True Skin ® may be preferred. In one aspect, the enclosures disclosed herein may be made from CHT’s True Skin ® 10 having a 10 Shore A hardness (or durometer) as disclosed in CHT “Technical Data Sheet” for True Skin ® 10 [Rev-i, 8-16-17], which is included by reference herein. In one aspect, the enclosures disclosed herein maybe made from CHT’s True Skin ® 20 having a 20 Shore A hardness (or durometer) as disclosed in CHT “Technical Data Sheet” for True Skin ® 20 [Rev-i, 8-16-17], which is included by reference herein. In one aspect, the enclosures disclosed herein may be made from CHT’s True Skin ® 30 having a 30 Shore A hardness (or durometer) as disclosed in CHT “Technical Data Sheet” for True Skin ® 30 [Rev-i, 8-16-17], which is included by reference herein.

[00100] As known in the art, any one of the enclosures disclosed herein may be fabricated from a liquid silicon rubber produced when combining two or more components, for example, a CHT True Skin liquid silicone rubber “A” and a CHT True Skin liquid silicone rubber “B” to produce the desired liquid silicone rubber when cured.

[00101] It is also envisioned that aspects of the invention maybe made from other liquid silicone rubbers, for example, a LSR marketed under the trademark SILBIONE® by Elkem Silicones of Lyon, France, or its equivalent. For example, in one aspect, one or more of the LSRs identified in Elkem’s “Silbione® Liquid Silicone Rubber (LSR) Elastomers” line card dated 06/ 2018, which is included by reference herein, may be used for an aspect of the invention.

[00102] In another aspect, the enclosures of the invention may be made from a LSR marketed by Dow Corning, or their equivalent.

[00103] In another aspect, enclosures of any one of the liners disclosed herein may be made from a LSR marketed under the trademark DRAGON SKIN™ by Smooth-On, Inc., or their equivalent. For example, one or more of the LSRs identified in Smooth-On’s Technical Bulletin “Dragon Skin™ Series,” having reference number 041619-JR, which is included by reference herein, may be used for an aspect of the invention.

[00104] In one aspect, the fluid (for example, a liquid) encased in the enclosures of the liners disclosed herein, for example, liners 10, 100, 102, 104, 106, or 108, may comprise any fluid, for example, a gas or a liquid. In one aspect, the fluid may be substantially water (for example, distilled water). In another aspect, the fluid may be an oil, for example, naturally occurring oil or synthetic oil. In one aspect, the fluid may include a diol, for example, ethylene glycol and/or propylene glycol. In one aspect, the fluid maybe a saline solution, or its equivalent.

[00105] In one aspect, the fluid (for example, a liquid) encased in the enclosures of the liners disclosed herein, for example, liners 10, 100, 102, 104, 106, or 108, may comprise a polydimethylsiloxane fluid, for example, a polydimethylsiloxane fluid marketed as a QM Diluent by CHT, or their equivalents; however, liquid 74 may comprises any polydimethylsiloxane fluid. However, in one aspect, the polydimethylsiloxane fluid marketed under the trademark QM Diluent may be preferred. In one aspect, the fluid encased in the enclosures of the liners disclosed herein may comprise QM Diluent 50 having a viscosity of about 50 centipoise (cps) as disclosed in CHT “Technical Data Sheet” for QM Diluent 50 [Rev-3, 8/7/ 17], which is included by reference herein. In one aspect, the fluid encased in the enclosures of the liners disclosed herein may comprise QM Diluent 100 having a viscosity of about 100 cps as disclosed in CHT “Technical Data Sheet” for QM Diluent 100 [Rev-3, 8/7/ 17], which is included by reference herein. In one aspect, the fluid encased in the enclosures of the liners disclosed herein may comprise QM Diluent 1000 having a viscosity of about 1000 cps as disclosed in CHT “Technical Data Sheet” for QM Diluent 1000 [Rev-3, 8-7-17], which is included by reference herein. In one aspect, the fluid encased in the enclosures of the liners disclosed herein may comprise QM Diluent 5000 having a viscosity of about 5000 cps, for which a “Technical Data Sheet” has not been identified. It is envisioned that fluids of higher viscosity, for example, QM Diluents having a viscosity greater than 5000 cps maybe used in aspects of the invention.

[00106] It is envisioned that fluids having other viscosities, for example, QM Diluents provided by CHT, may also be used, for example, by appropriately combining at least two fluids of known viscosity, as known in the art.

Accordingly, in one aspect, polydimethylsiloxane fluids of different viscosities, such as, a CHT QM Diluents, can be mixed or otherwise combined to provide a fluid having a viscosity of at least 50 cps that can be used as a fluid in an aspect of the invention. Similarly, in one aspect, polydimethylsiloxane fluids of different viscosities, such as, a CHT QM Diluents, can be mixed or otherwise combined to provide a fluid having a viscosity of at least 100 cps that can be used as a fluid in an aspect of the invention. In one aspect, polydimethylsiloxane fluids of different viscosities, such as, a CHT QM Diluents, can be mixed or otherwise combined to provide a fluid having a viscosity of at least 500 cps that can be used as a fluid in an aspect of the invention. In one aspect, polydimethylsiloxane fluids of different viscosities, such as, a CHT QM Diluents, can be mixed or otherwise combined to provide a fluid having a viscosity of at least 1000 cps, or at least 2000 cps, or at least 3000 cps, or at least 4000 cps, or at least 5000 cps, or at least 6000 cps, or at least 8000 cps that can be used as a fluid in an aspect of the invention.

[00107] It is envisioned that a broad range of fluids, including liquids or gases, may be used with aspects of the invention, for example, a liquid or gas compatible with the materials of the enclosures disclosed herein, for instance, fluids that are impermeable to the material of the enclosure disclosed herein and/or fluids having a boiling point where the liquid will not evaporate under the expected working conditions. In one aspect, the liquid may have a broad range of viscosities, for example, any fluid having a viscosity, for instance, having a viscosity of at least 0.01 cps. In one aspect, the liquid may have a viscosity from less than 50 cps to greater than 5,000 cps. In one aspect, the fluid maybe oil, an alcohol, and/ or a diol. For example, the oil may be a mineral oil or a vegetable oil, and the oil may have a natural source or be synthetic. In one aspect, the fluid may be ethylene glycol and/ or a propylene glycol. In one aspect, the fluid may comprise a polyol, for example, a polyether polyol. In other aspects, the liquid may be water, for example, distilled water.

[00108] Though not shown in Figures 1 through 13, it is envisioned that any one of more of the liners disclosed herein may be enhanced with appropriate text and/or logos. For example, instructions for use and/or marketing information or logos maybe applied to a surface of the liners disclosed herein. In addition, it is envisioned that the aesthetic appeal of aspects of the invention may be enhanced by introducing dyes or colorants to the enclosures and/or to the fluid encased within the enclosures.

[00109] In one aspect of the invention, the liners disclosed herein maybe enhanced with an appropriate mountings or attachment mechanisms or devices. For example, in one aspect, any one of the liners disclosed herein may include a mounting device, for example, one or more straps (with or without connectors), holders, interfaces, and/or retainers.

[00110] In another aspect, any one of the liners disclosed herein may be enhanced with an attachment or retention mechanism or device, for example, one or more fasteners. In one aspect, any one of the liners disclosed herein may include one or more hook and loop fasteners, for example, a Velcro-type hook and loop fastener, as known in the art. The hook and loop fastener maybe used to facilitate or enhance mounting and/or locating any one of the liners disclosed herein, for example, to a mating hook and look fastener. In one aspect, a hook and loop fastener may be attached to any one of the liners disclosed herein with mounting hardware and/or with an adhesive. In another aspect, a fastener, such as, a hook and loop faster, may be molded into any one of the enclosures of the liners disclosed herein. For example, in one aspect, a hook and loop fastener may be molded into any one or more of the bosses 42 shown in FIGURES 1 through 4 during a molding process.

[00111] In one aspect, any one or more of the liners disclosed herein may include a fabric sheet, for example, a reinforcing fabric sheet as disclosed in pending US application 16/595,135, filed on October 7, 2019, the disclosures of which are incorporated by reference herein in their entirety.

[00112] In one aspect, any one or more of the liners disclosed herein may be fabricated by any one or more of the methods disclosed in pending US application i5/833,747filed on December 6, 2017, now US patent 10,531,699, or pending application 16/738,234 filed on January 9, 2020, the disclosures of which are incorporated by reference herein in their entirety.

[00113] FIGURE 14 is a bottom perspective view of a helmet assembly 111 according to another aspect of the invention. FIGURE 15 is a perspective view of the helmet assembly 111 shown in FIGURE 14 flipped over. As shown in FIGURES 14 and 15 helmet assembly 111 includes a helmet shell 112, for example, having a brim 113, a helmet suspension or liner retainer 114 mounted in helmet shell 112, and one or more protective helmet liners 116 retained by helmet suspension or liner retainer 114. According to aspects of the invention, liner 116 may comprise liner 10, 100, 102, 104, 106, and 108 shown and descried with respect to FIGURES 1 through 13, among others. As known in the art, helmet suspensions like suspension 114 provide a gap between the helmet shell 112 and the head of the wearer (not shown), and this gap typically aids in minimizing the transmission of impact forces on the helmet shell 112 and/ or redirects the impact forces away from the head and spine of the user. Though helmet assembly 111 shown and described with respect to FIGURES 14 and 15 may be referred to herein as a “helmet” or a “helmet assembly,” it is envisioned that aspects of the invention may be applied to any form of “headgear” that would benefit from aspects of the invention. For example, in FIGURES 14 and 15, for the sake of illustration, helmet 112 is shown as a construction helmet, or a “hard hat” as known in the art, or a “bump cap” as known in the art; however, aspects of the invention can be applied to any helmet or headgear and are not limited to hard hats and related construction helmets.

[00114] FIGURE 16 is an exploded perspective view of the helmet assembly 111 shown in FIGURE 15. As shown in FIGURES 14 through 16, helmet suspension, liner interface, or liner retainer 114 may be substantially similar in construction to conventional helmet interfaces or suspensions. Though structure 114 may be referred to as a “suspension” herein, it is to be understood that structure 114 may also be referred to as an “interface” or as a “retainer.” As shown, and as is typical in the art, helmet suspension or liner interface 114 may include a head strap 118 and head strap 118 may have a plurality of mounting clips 120 adapted to engage corresponding recesses 122 of helmet shell 112. Helmet suspension 114 may also include some form of adjustment mechanism for varying the size of helmet suspension 114, for example, the ratchet -type mechanism 117 shown in FIGURE 16, though any form of adjustment device or mechanism maybe provided according to aspects of the invention. However, according to aspects of the invention, helmet suspension 114 is uniquely adapted to retain one or more helmet liners 116, for example, one or more fluid-containing, impact dissipating liners disclosed herein.

[00115] As shown in FIGURE 16, according to one aspect of the invention, helmet suspension 114 includes at least one, but typically, a plurality of projections 124, 126, 128, and 130 adapted to engage one or more liners 116. For example, in one aspect, one or more of projections 124, 126, 128, and 130 may engage any one or more recesses, holes, or cavities in one or more liners 116. In one aspect, one or more of projections 124, 126, 128, and 130 may engage one or more corresponding recesses or cavities in one or more liners 116, for example, one or more of cavities or recesses 134, 136, 138, and 140 of liner 116. For example, in one aspect, projection 124 may engage recess 134, projection 126 may engage recess 136, projection 128 may engage recess 138, and projection 30 may engage recess 140.

[00116] As shown in FIGURE 16, one or more suspension components 129 may be provided to suspension 114 to accommodate the desired presence of one or more projections 124, 126, 128, and 130. As shown in FIGURE 16, in one aspect, one or more suspension components 129 may comprise extensions or spacers, for example, similar in construction to head strap 118, and be mounted to head suspension 114 by connectional means, for example, with an adhesive, with mechanical fasteners (for example, with hook and loop-type fasteners such as, Velcro brand hook and loop type fasteners), or be integrally formed with suspension 114. According to this aspect of the invention, one or more suspension components 129 having one or more projections 124, 126, 128, or 130 maybe provided where otherwise a structure for mounting a projection would not be present. In other aspects, for example, where a portion of head strap 118 can accommodate a projection, as disclosed herein, or in areas where no projection is required, a suspension components 129 maybe omitted. [00117] According to aspects of the invention, liner n6 may comprise any one or more protective, or energy or impact absorbing or dissipating liners having holes, recesses, or cavities adapted to receive one or more projections 124, 126, 128, or 130 of suspension 114. In one aspect of the invention, liner 116 maybe a fluid containing liner, for example, a fluid-containing liner having holes, recesses, or cavities sized and positioned to receive one or more projections of suspension 114. In one aspect, liner 16 maybe a liner disclosed in US patent 8,856,972 or, liner 116 maybe the fluid containing liner disclosed herein, for example, the lines shown and described with respect to FIGURES 1 through 13. Kirsh Helmets, Inc. of Schenectady, New York, markets these liners and related liners under the trademark FLUID DISPLACEMENT LINER™.

[00118] As shown in FIGURE 16 and as shown and described, for example, with respect to FIGURES 1 through 13, liner 116 maybe an impact dissipating helmet liner having one or more, or a plurality of, flexible, fluid impermeable enclosures 142, each of the enclosures 142 having opposing end walls, a sidewall extending between the opposing end walls; and a fluid contained in each of the plurality of enclosures. One or more of the plurality of flexible, fluid impermeable enclosures 142 maybe in fluid communication with at least one of the other enclosures 142 via a passage comprising a restriction between the enclosures. In one aspect, as shown and described, for example, with respect to FIGURES 1 through 13, enclosures 142 may not be in fluid contact, for example, though enclosures 142 are shown in FIGURE 16 as interconnect, enclosures 142 may be individual separate enclosures 142. In one aspect, for example, as shown and described, for example, with respect to FIGURES 1 through 13, the enclosures 142 of liner 116 may further comprise one or more, or a plurality of, cavities, or through holes, extending between the upper wall and the lower wall of each of the plurality of enclosures 142. In another aspect, for example, as shown and described, for example, with respect to FIGURES 1 through 13, the enclosures 142 of liner 116 may further comprise a cavity sidewall extending from the upper wall to the lower wall of each of the plurality of cavities. [00119] As shown in FIGURE 16 and as shown and described, for example, with respect to FIGURES l through 13, liner 116 and any liner disclosed herein may comprise one or more enclosures 142 having a fluid (not shown) encased within enclosures 142. The fluid in liner 116 or in any liner disclosed herein maybe a liquid or a gas, or any fluid disclosed herein. In one aspect, enclosures 142 of liner 116 or of any liner disclosed herein may comprise or be made any one or more of the materials disclosed herein, for example, a liquid silicone rubber (LSR), for example, a cured LSR. In one aspect, enclosure 142 of liner 116 or of any liner disclosed herein may comprise a “medical grade” LSR, as known in the art. In one aspect, enclosure 142 or any liner disclosed herein may comprise or be made of a liquid silicone rubber marketed by CHT USA (formerly Quantum Silicones (QSi)) under the trademark True Skin® or its equivalent; however, enclosure 142 of liner 116 or of any liner disclosed herein may comprise any liquid silicone rubber (LSR).

[00120] In one aspect, the fluid encased in enclosure 142 of liner 116, or in any liner disclosed herein, may comprise a polydimethylsiloxane fluid (also know as a “silicone fluid), for example, a polydimethylsiloxane fluid marketed by CHT USA as a QM Diluent or its equivalent, as disclosed herein; however, the liquid may comprise any polydimethylsiloxane fluid. As known in the art, polydimethylsiloxane comprises a group of polymeric organosilicon compounds that are commonly referred to as “silicones.” Polydimethylsiloxane maybe abbreviated “PDMS’ and has the chemical formula [(CH₃)₂SiO]_n. However, in other aspects, the fluid encased in enclosure 142 of liner 116, or in any liner disclosed herein, may be any fluid disclosed herein, including water, such as, distilled water.

[00121] According to aspects of the invention, enclosures 142 of liner 16, or in any liner disclosed herein, may take any conventional size and shape, for example, depending upon the size and/ or shape of the helmet shell 112 in which liner 116 is used with, for example, a construction helmet. [00122] FIGURE 17 is a bottom perspective view of an assembly 115 of the helmet suspension 114 and helmet or headgear liner 116 shown in FIGURE 16. FIGURE 18 is a top perspective view of assembly 115 shown in FIGURE 17. FIGURE 19 is a bottom plan view of the assembly 115 shown in FIGURE 18. FIGURE 20 is a front elevation view of assembly 115 shown in FIGURE 19. FIGURE 21 is a rear elevation view of assembly 115 shown in FIGURE 20 and FIGURE 21 is a side elevation view of assembly 115 shown in FIGURE 21.

[00123] According to aspects of the invention, as shown in FIGURES 14 through 22, enclosures 142 of liner 116 may comprise a plurality of interconnected enclosures 142 or components, for example, sub-enclosures, as shown in FIGURES 1 through 13. For example, enclosures 142 may comprise a multi enclosure cylindrical shape or a multi-component cylindrical shape. As shown in FIGURES 14 through 22, in one aspect, enclosures 142 of liner 116 may comprise a plurality of interconnected right circular cylindrical enclosures 142 or components having a fluid. As shown in FIGURES 14 through 22, in one aspect, liner 116 may comprise five circular cylindrical enclosures 142 or components having fluid. However, it is envisioned that aspects of the invention may have one or more, for example, 2 of more, interconnected enclosures or components 142.

[00124] As shown in FIGURES 14 through 22, liner 116 may comprise multiple enclosures or components 142 arranged in a somewhat uniform radial pattern. However, it is envisioned that, according to aspects of the invention, liner 116 may take many varying arrangements of any number of enclosures or components 142 and/or enclosures or component shapes, such as, polygonal cylindrical in shape, for example, rectangular cylindrical in shape or square cylindrical in shape, pentagonal cylindrical in shape, or hexagonal cylindrical in shape, among other cylindrical shapes. Other shapes for enclosures 142 are also envisioned, for example, as shown FIGURE 30. [00125] FIGURES 23A and 23B are detailed perspective views of the engagement of the projections 124, 126, 128, and 130 on suspension or headgear liner retainer 114 (not shown) with the cavities or recesses 134, 136, 138, and 140 of liner 116 shown in FIGURE 16 before and after engagement, respectively, according to one aspect of the invention. Phantom arrows in FIGURE 23A represent the direction of engagement of projections 124, 126, 128, and 130 with the cavities or recesses 134, 136, 138, and 140. Though in FIGURES 23A and 23B four (4) different projections 124, 126, 128, and 130 are shown engaging four (4) cavities or recesses 134, 136, 138, and 140 in liner 116, according to aspects of the invention, any combination of one or more projections 124, 126, 128, and 130 maybe provided to suspension 114 to engage one or more cavities or recesses 134, 136, 138, and 140 in liner 116. For example, in one aspect, 1, 2, 3, 4, 5, 6, or more projections 124, 126, 128, and 130 maybe provided for suspension 114 in which each projection 124, 126, 128, or 130 is adapted to engage 1, 2, 3, 4, 5, 6 or more recesses or cavities 134, 136, 138, or 140 in liner 116.

[00126] Details of projections 124, 126, 128, and 130 on suspension or headgear liner retainer 114 and their mounting to suspension or headgear liner strap 118 are shown in FIGURES 24A through 29B.

[00127] FIGURES 24A and 24B are detailed perspective views of the engagement of projection 124 shown in FIGURES 23A and 23B with head strap 118 of suspension 114 before and after engagement, respectively, according to one aspect of the invention. Only a representative portion of head strap 118 of suspension 114 is shown in FIGURES 24A and 24B.

[00128] As shown in FIGURE 24A, in this aspect, projection 124 may comprise a cylindrical body 150 having a first, free end 152, and a second end 154 mounted to a mounting strip or tab 156. In one aspect, cylindrical body 150 may be mounted to tab 156 with an adhesive, a mechanical fastener, or be molded or formed integrally with tab 156. Though in FIGURES 24A and 24B projection 124 is shown as a circular cylindrical body 150, it is envisioned that cylindrical body 150 may be polygonal cylindrical, for example, square cylindrical, or elliptical cylindrical (for example, consistent with the shape of the mating cavity 134). As shown in FIGURE 24A, strip or tab 156 includes a hole 158, for example, a hole 158 having a reinforcement or grommet 160. According to this aspect, hole 158 of tab 158 is sized and positioned to receive a fastener or plug 162 and retain fastener 162 to secure projection 124 to head strap 118. As shown, head strap 118 may include one or more holes 164 positioned and sized to receive fastener 162 and, when fastener 162 is retained in hole 158 in strap 156, at least temporarily secures projection 124 to head strap 118.

[00129] In one aspect, fastener or plug 162 may include a stem 166 sized to engage and be retained by hole 158 and a cap or head 168 sized to prevent passage of fastener 162 through hole 164 wherein, when stem 166 engages and is retained by hole 158, fastener 162 at least temporarily retains projection 124 on head strap 118 of suspension 114. In one aspect, strip 156 maybe elastomeric of flexile, wherein stem 166 of fastener 162 flexibly engages hole 158 to retain projection 124 on head strap 118. For example, in one aspect, fastener 166 may be engaged and disengaged from strip 156, for example, to facilitate assembly/ disassembly and/or replacement of projection 124.

[00130] FIGURE 24B is a detailed perspective view similar to FIGURE 24A after engagement of fastener 162 with hole 158 of strip 156 of projection 124. As indicated by arrow 169 in FIGURE 24B, prior to or after engagement of projection 124 with head strap 118, projection 124 may engage recess 134 in liner 116 and, according to aspects of the invention, at least partially assist in retaining liner 116 on suspension 114 and in helmet shell 112 (not shown).

[00131] FIGURES 25A and 25B are detailed perspective views of the engagement of projection 126 shown in FIGURES 23A and 23B with head strap 118 of suspension 114 before and after engagement, respectively, according to an aspect of the invention. Only a representative portion of head strap 118 of suspension 114 is shown in FIGURES 25A and 25B. [00132] As shown in FIGURE 23A, in this aspect, projection 126 may comprise a cylindrical body 170 having a first, free end 172, and a second end 174 mounted to mounting strip or tab 176. In one aspect, cylindrical body 170 may be mounted to tab 176 with an adhesive, a mechanical fastener, or be molded or formed integrally with tab 176. Though in FIGURES 25A and 25B projection 126 is shown as a circular cylindrical body 170, it is envisioned that cylindrical body 170 may be polygonal cylindrical, for example, square cylindrical, or elliptical cylindrical (for example, consistent with the shape of the mating cavity 136).

[00133] As shown in FIGURE 25A, strip or tab 176 includes a projection 178 extending from tab 176. In this aspect, projection 178 includes a stem 180 mounted to tab 176 and a cap or head 182 sized and positioned to engage and at least temporarily be retained by a hole 184 in head strap 118. As shown, head strap 118 may include one or more holes 184 positioned and sized to receive projection 178. In one aspect, head strap 118 maybe elastomeric or flexible, wherein projection 178 of projection 126 may flexibly engages hole 184 to retain projection 26 on head strap 18. In one aspect, as shown in FIGURE 25A, head strap 118 may include grooves or indentations 186 about hole 184 to enhance the flexibility of a portion of head strap 118 and thus enhance the engagement of projection 178 in hole 184. For example, in one aspect, projection 178 maybe engaged and disengaged from head strap 118, for example, to facilitate assembly/ disassembly and/or replacement of projection 126.

[00134] FIGURE 25B is a detailed perspective view similar to FIGURE 25A after engagement of projection 178 of projection 126 with hole 184 of head strap 118.

As indicated by arrow 187 in FIGURE 25B, prior to or after engagement of projection 126 with head strap 118, projection 126 may engage recess 136 in liner 116 and, according to aspects of the invention, at least partially assist in retaining liner 116 on suspension 114 and in helmet shell 112 (not shown).

[00135] FIGURES 26A, 26B, and 26C are detailed perspective views of the sequential engagement of projection 130 shown in FIGURES 23A and 23B with head strap 118 of suspension 114 according to an aspect of the invention. Only a representative portion of head strap 118 of suspension 114 is shown in FIGURES 26A, 26B, and 26C.

[00136] As shown in FIGURE 26A, in this aspect, projection 130 may comprise a cylindrical body 190 having a first, free end 192, and a second end 194 mounted to mounting strip or tab 196 via a cylindrical stem 198. In one aspect, cylindrical body 190 maybe mounted to tab 196 and stem 198 with an adhesive, a mechanical fastener, or be molded or formed integrally with tab 196 and stem 198. Though in FIGURES 26A, 26B, and 26C projection 130 is shown as a circular cylindrical body 190, it is envisioned that cylindrical body 190 maybe polygonal cylindrical, for example, square cylindrical, or elliptical cylindrical (for example, consistent with the shape of the mating cavity 140).

[00137] As shown in FIGURES 26A and 26B, strip or tab 196 is sized and shaped to engage elongated hole or slot 200 in head strap 118. According to this aspect, elongated hole or slot 200 is sized and positioned to receive tab 196, and, when tab 196 is rotated after insertion into slot 200 (as shown by curved arrow 204 in FIGURE 26B) and tab 196 is positioned as shown in FIGURE 26C, tab 196 is at least temporarily retained in slot 200 to at least temporarily secure projection 130 to head strap 118. In one aspect, the shoulder of cylindrical body 190 adjacent the stem 198 provides one bearing surface and a side of tab 196 defines a second bearing surface which engage the opposing surfaces of head strap 118 to at least temporarily secure projection 130 to head strap 118. For example, in one aspect, tab 196 maybe engaged with and disengaged from head strap 118, for example, to facilitate assembly/disassembly and/or replacement projection 130.

[00138] FIGURE 26C is a detailed perspective view similar to FIGURES 26A and 26B after engagement of tab 196 with elongated hole or slot 200 of head strap 118. As indicated by arrow 206 in FIGURE 26C, prior to or after engagement of projection 130 with head strap 118, projection 130 may engage recess 140 in liner 116 and, according to aspects of the invention, at least partially assist in retaining liner 116 on suspension 114 and in helmet shell 112 (not shown).

[00139] FIGURES 27A, 27B, and 27C are detailed perspective views of the sequential engagement of projection 28 shown in FIGURES 23A and 23B with head strap 118 of suspension 114 according to an aspect of the invention. Only a representative portion of head strap 118 of suspension 114 is shown in FIGURES 27A, 27B, and 27C.

[00140] As shown in FIGURE 27A, in this aspect, projection 128 may comprise a cylindrical body 210 having a first, free end 212, and a second end 214. As shown, second end 214 may include an annular recess 216 adapted to engage head strap 118. In one aspect, head strap 118 includes an elongated hole or slot 220 having a through hole 222 at one end of slot 220. Though in FIGURES 27A, 27B, and 27C, projection 128 is shown as a circular cylindrical body 210, it is envisioned that cylindrical body 210 maybe polygonal cylindrical, for example, square cylindrical, or elliptical cylindrical (for example, consistent with the shape of the mating cavity 138). As shown in FIGURES 27A and 27B, second end 214 and annular recess 216 are sized and shaped to engage through hole 222 and slot 220 in head strap 118. According to this aspect, elongated hole or slot 220 is sized and positioned to receive second end 214 and annular recess 216, and, when second end 214 and annular recess 216 are translated along slot 220 (as shown by arrow 224 in FIGURE 27B) and second end 214 and annular recess 216 are positioned as shown in FIGURE 27C, projection 128 is at least temporarily retained in slot 220 to at least temporarily secure projection 128 to head strap 118. In one aspect, the opposing shoulders of cylindrical body 210 adjacent to the annular recess 216 provide bearing surfaces, which engage the opposing surfaces of head strap 118 to at least temporarily, secure projection 128 to head strap 118. For example, in one aspect, projection 128 maybe engaged with and disengaged from head strap 118, for example, to facilitate assembly/disassembly and/or replacement projection 128. [00141] FIGURE 27C is a detailed perspective view similar to FIGURE 27A and 27B after engagement and translation of projection 128 within elongated hole or slot 220 of head strap 118. As indicated by arrow 226 in FIGURE 27C, prior to or after engagement of projection 128 with head strap 118, projection 128 may engage recess 138 in liner 116 and, according to aspects of the invention, at least partially assist in retaining liner 116 on suspension 114 and in helmet shell 112 (not shown).

[00142] FIGURES 28A and 28B are detailed perspective views of the engagement of another projection 250 that maybe used for the engagement of liner 116 with head strap 118 of suspension 114 shown in FIGURES 23A and 23B before and after engagement, respectively, according to another aspect of the invention.

Only a representative portion of head strap 118 of suspension 114 is shown in FIGURES 28A and 28B.

[00143] As shown in FIGURE 28A, in this aspect, projection 250 may comprise a cylindrical body 252 having a first, free end 254, and a second end 256 mounted to head strap 118. As shown, cylindrical body 252 of projection 250 may be mounted to head strap 118 with a mechanical fastener 258, for example, a plastic rivet adapted to engage head strap 118. Though in FIGURES 28A and 28B cylindrical body 252 is shown as a circular cylindrical body 252, it is envisioned that cylindrical body 252 maybe polygonal cylindrical, for example, square cylindrical, or elliptical cylindrical. As shown in FIGURE 28A, head strap 118 includes a hole 260, and, according to this aspect, hole 260 is sized and positioned to receive a fastener 258 and retain fastener 258 to secure projection 250 to head strap 118. Head strap 118 may include one or more holes 260 positioned and sized to receive fasteners 258 and, when fastener 258 is retained in whole 260, fastener 258 at least temporarily secures projection 250 to head strap 118.

[00144] In one aspect, fastener 258, for example, a plastic rivet, may include a stem 262 sized to penetrate hole 260 and a cap or head 264 sized to prevent passage of fastener 258 through hole 260 wherein, when stem 262 engages and is retained by cylindrical body 252, fastener 258 at least temporarily retains projection 250 on head strap 118 of suspension 114.

[00145] As shown, in one aspect, stem 262 of fastener 258 may include a pointed distal end and external serrations or threads adapted to engage the second end 256 cylindrical bodies 252 of projection 250. Fastener 258 maybe metallic or non-metallic, for example, a plastic rivet. In one aspect, the second end 256 of cylindrical body 252 may include a hole or penetration adapted to receive and retain stem 262, for example, cylindrical body 252 may include a blind hole adapted to receive and engage serrations on stem 262 or internal threads adapted to receive corresponding external threads on stem 262. In one aspect of the invention, cylindrical body 252 may not include a hole or penetration, but comprise a pliable or flexible material, such as an elastomer, that is penetrable by stem 262, for example, by manually compressing fastener 258 into cylindrical body 252, by compressing fastener 258 into cylindrical body 252 with a tool for example, a power tool, or by compressing fastener 258 into cylindrical body 252 by automated means. According to this aspect, the plastic or flexible penetration and engagement of stem 262 into cylindrical body 252 maybe sufficient to at least temporarily secure fastener 258 in cylindrical body 252 and at least temporarily secure projection 250 on head strap 118. For example, in one aspect, fastener or rivet 258 may be engaged and disengaged from head strap 118, for example, to facilitate assembly/disassembly and/or replacement of projection 250.

[00146] FIGURE 28B is a detailed perspective view similar to FIGURE 28A after engagement of fastener 258 with hole 260 of head strap 118 and engagement of cylindrical body 252 of projection 250. As indicated by arrow 266 in FIGURE 28B, prior to or after engagement of projection 250 with head strap 118, projection 250 may engage a hole or recess in liner 116 and, according to aspects of the invention, at least partially assist in retaining liner 116 on suspension 114 and in helmet shell 112 (not shown).

[00147] FIGURES 29A and 29B are detailed perspective views of the engagement of another projection 270 that maybe used for the engagement of liner 116 with head strap 118 of suspension 114 shown in FIGURES 23A and 23B before and after engagement, respectively, according to another aspect of the invention.

Only a representative portion of head strap 118 of suspension 114 is shown in FIGURES 29A and 29B.

[00148] As shown in FIGURE 29A, in this aspect, projection 270 may comprise a cylindrical body 272 having a first, free end 274, and a second end 276 mounted to head strap 118. As shown, cylindrical body 272 of projection 270 may include a fastening arrangement comprising a flexible conical cap 278 adapted to be received and be retained in a hole 280 in head strap 118. In one aspect, the fastening arrangement may include a guide projection or pin 282 adapted to facilitate alignment of conical cap 278 with hole 280. As shown in FIGURE 29A, head strap 118 includes a hole 280, and, according to this aspect, hole 280 is sized and positioned to receive conical cap 278 and retain conical cap 278 to secure projection 270 to head strap 118. Head strap 118 may include one or more holes 280 positioned and sized to receive conical caps 278 and, when conical cap 278 is retained in hole 280, conical cap 278 at least temporarily secures projection 270 to head strap 118.

[00149] In one aspect, projection 270 may be engaged with head strap 118 by manually compressing projection 270 through hole 280, by compressing projection 270 into hole 280 with a tool, for example, a power tool, or by compressing projection 270 into hole 280 by automated means. According to this aspect, the plastic or flexible penetration and engagement of conical cap 278 into hole 280 maybe sufficient to at least temporarily secure projection 270 on to head strap 118. For example, in one aspect, projection 270 maybe engaged and disengaged from head strap 118, for example, to facilitate assembly/disassembly and/or replacement of projection 270.

[00150] FIGURE 29B is a detailed perspective view similar to FIGURE 29A after engagement of projection 270 with hole 280 of head strap 118. As indicated by arrow 284 in FIGURE 29B, prior to or after engagement of projection 270 with head strap 118, projection 270 may engage a hole or recess in liner 116 and, according to aspects of the invention, at least partially assist in retaining liner 116 on suspension 114 and in helmet shell 112 (not shown).

[00151] In the aspects shown in FIGURES 28A, 28B, 29A, and 29B, projection 250 or projection 270 may comprise a commercially available clip, retainer, or pin, for example, a conventional automotive mounting clip or body clip, as known in the art.

[00152] According to aspects of the invention, one or more of the mountings of projections 124, 126, 128, 130, 250, and 270 to head strap 118 shown in FIGURES 24A through 29B maybe provided. For example, one or more projections 124,

126. 128. 130, 250, or 270 maybe mounted to head strap 118 by means of one of more of the mounting arrangements shown in FIGURES 24A and 24B; shown in FIGURES 25A and 25B; shown in FIGURES 26A, 26B, and 26C; shown in FIGURES 27A, 27B, and 27C, shown in FIGURES 28A and 28B, or shown in FIGURES 29A and 29B. In another aspect, one or more projections 124, 126,

128. 130, 250, or 270 maybe mounted to head strap 118 as shown in FIGURES 24A and 24B; one or more projections may be mounted to head strap 118 as shown in FIGURES 25A and 25B; one or more projections maybe mounted to head strap 118 as shown in FIGURE 26A, 26B, and 26C; one or more projections may be mounted to head strap 118 as shown in FIGURE 27A, 27B, and 27C; one or more projections maybe mounted to head strap 118 as shown in FIGURES 28A and 28B, or one or more projections maybe mounted to head strap 118 as shown in FIGURES 29A and 29B. Various combinations of the mountings shown and described with FIGURES 24A through 29B will be apparent to those of skill in the art.

[00153] FIGURE 30 is a perspective view of an arrangement 230 for mounting a liner 232 to a helmet suspension or headgear liner retainer 234 according to another aspect of the invention. FIGURE 31 is a detailed perspective view of the arrangement 230 for mounting a liner 232 to the helmet suspension 234 shown in FIGURE 30. Suspension 234 maybe similar to helmet suspension 114 shown in and described with respect to FIGURES 14 through 22 above. For example, suspension 234 may have a head strap 236, for instance, similar to head strap 118 having mounting clips 237 adapted to engage corresponding recesses in a helmet shell (not shown). Liner 232 shown in FIGURES 30 and 31 maybe similar in design and construction to liners 10, 100, 102, 104, 106, 108, and, 116 disclosed herein, for example, having an upper wall, a lower wall, side walls, through holes, and containing a fluid. However, according to the aspect shown in FIGURES 30 and 31, liner 232 may comprise any appropriate shape and includes one or more mounting extensions, mounting loops, or mounting lugs 238 having a recess, hole, or cavity 240. Mounting lugs 238 maybe provided or mounted to any surface of liner 232, but may typically be mounted or provided at the periphery of liner 232. According to this aspect of the invention, one or more extensions, loops, or lugs 238 maybe provided for a liner having recesses, holes, or cavities, for example, provided to liner 116 disclosed herein, to facilitate engagement of a liner with projections on head strap 236.

[00154] According to this aspect of the invention, head strap 236 may include one or more projections 242. Projections 242 maybe mounted, for example, removably mounted, to head strap 236 by any one of the mountings shown in FIGURES 24A through 29B. For example, in one aspect, projection 242 shown in FIGURE 30 maybe mounted to head strap 236 as shown in FIGURES 25A and 25B. [00155] As shown in FIGURES 30 and 31, in one aspect, mounting extensions, mounting loops, or mounting lugs 238 may comprise a cylindrical body having a cross section conducive to the shape and construction of liner 232. For example, as shown in FIGURES 30 and 31, extension, loop, or lug 238 may comprise a rectangular cylindrical body having a radiused distal end 244. However, it is envisioned that the cylindrical shape of extension, loop, or lug 238 may vary broadly, for example, comprise a polygonal cylindrical body, a circular cylindrical body, or an elliptical cylindrical body, and provide the desired engagement with head strap 236 disclosed herein.

[00156] In one aspect, recess, hole, or cavity 240 in lug 238 may comprise a through hole, as shown in FIGURES 30 and 31, or be a blind recess or cavity in the surface of liner 232 opposite the surface shown in FIGURES 30 and 31. In addition, it is envisioned that recess, hole, or cavity 240 may have a circular cross section, as shown, or have a polygonal cross section or an elliptical cross section, for example, compatible with the shape of projection 242. For instance, projection 242 may also have a circular cross section, as shown in FIGURES 30 and 31, or a polygonal cross section or an elliptical cross section.

[00157] According to the aspect shown in FIGURES 30 and 31, mounting extensions, mounting loops, or mounting lugs 238 maybe attached or mounted to liner 232 by any conventional means, for example, lugs 238 maybe mounted to liner 232 with an adhesive, with one or more mechanical fasteners, or be integrally formed or molded with liner 232. In one aspect, mounting lugs 238 may be formed integrally with liner 232 during the fabrication of liner 232, for example, in a molding process or in a molding process with assembly with an adhesive.

[00158] In one aspect, mounting extensions, mounting loops, or mounting lugs 238 maybe fabricated from the same materials from which liner 232 is fabricated, for example, any one of the LSRs disclosed herein. In one aspect, mounting extensions, mounting loops, or mounting lugs 238 may be hollow or non-hollow. For example, lug 238 may comprise a solid material, for example, a solid LSR, or lug 238 maybe hollow, for example, with or without an internal fluid, such as, one of the fluids disclosed herein. In one aspect, when lug 238 includes a hollow cavity containing a fluid, the fluid-containing cavity of lug 238 may or may not be in fluid communication with one or more fluid-containing cavities of liner 232.

[00159] In the aspects of the invention shown and described herein, the projections disclosed herein, for example, projections 124, 126, 128, 130, 242, 250, or 270, are generally illustrated as mounted to a head strap and directed outward from the head strap, for example, radially outward from the head strap, and engage a hole or cavity in a liner positioned external to or outward of the head strap of the retainer. However, it is envisioned that, in one aspect, one or more projections from any one of the head straps of retainers disclosed herein may be directed inward from the head strap, for example, radially inward, for instance, opposite the direction of projection shown herein and toward the head of the wearer. For example, as shown in FIGURE 16, one or more of projections 124, 126, 128, and/or 130 maybe directed inward, opposite to the direction shown in FIGURE 16, and engage holes or cavities in a liner 116 positioned, for example, within retainer 114. In another example, with respect to FIGURES 24A through 31, one or more of projections 124, 126, 128, 130, 242, 250, or 270 may be directed inward, opposite to the direction shown, and engage holes or cavities in a liner positioned, for example, within a retainer or interface.

[00160] It is envisioned that aspects of the invention maybe implemented in a broad range of materials. For example, the head straps and projections disclosed herein, for example, projections 124, 126, 128, 130, 242, 250, or 270, maybe fabricated or formed from a broad range of materials, for example, a plastic, an elastomer, a metal, and even wood. In one aspect, the projections may comprise one or more of the following plastics: a polyamide (PA), for example, nylon; a polyethylene (PE), both high-density polyethylene (HDPE) and low-density polyethylene (LDPE); a polyethylene terephthalate (PET); a polypropylene (PP); a polyester (PE); a polytetrafluoroethylene (PTFE); a polystyrene (PS); an acrylonitrile butadiene styrene (ABS); a polycarbonate (PC); or a polyvinylchloride (PVC); among other plastics. In one aspect, the projections may comprise one or more of the following elastomers or “rubbers”: a natural polymer, such as, polyisoprene rubber, or a synthetic polymer, such as, a neoprene, a thermoplastic elastomer, a thermoplastic rubber, and a polyvinyl chloride, or an ethylene propylene diene monomer (EPDM) rubber, and the like. In one aspect, projections 124, 126, 128, 130, 242, 250, or 270 maybe fabricated or formed from a foam-like material, for example, a foam rubber or a closed-cell foam rubber, for instance, comprising one or more of the elastomeric or rubber materials listed above.

[00161] The size and shape of the projections, for example, projections 124, 126, 128, 130, 242, 250, or 270, may vary broadly depending upon the application of aspects of the invention. For example, the projections may have an outer dimension or width ranging from about 0.125 inches to about 3 inches, but typically may have an outer dimension of between about 0.25 inches and about 1 inch, for example, about 0.375 inches. The projections may have a length ranging from about 0.125 inches to about 3 inches, but typically may have a length between about 0.25 inches and about 1 inch, for example, about 0.375 inches.

[00162] FIGURE 32 is a top perspective view of a helmet or headgear assembly 310 according to a further aspect of the invention. FIGURE 33 is an exploded perspective view of the helmet or headgear assembly 310 shown in FIGURE 32.

In the following disclosure of the invention, though assembly 10 and its components maybe referred to as a “helmet assembly,” a “helmet shell,” or a “helmet,” it is envisioned and understood that assembly 310 may comprise any form of “headgear,” that is, not specifically a protective helmet. For example, aspects of the invention may be applicable to any form of headwear, protective or otherwise. It is also envisioned that aspects of the invention may be applicable to any form of protective barrier, for example, body armor or any form of surface protection.

[00163] As shown in FIGURES 32 and 33, in one aspect, headgear assembly 310 includes a helmet shell 312 and a helmet or headgear liner assembly 314. According to one aspect of the invention, headgear liner assembly 314 may comprise a headgear liner 316, for example, a fluid-filled headgear liner as disclosed in US Patents 8,856,972 and 10,531,699, or in pending US applications 16/595,135 filed on Oct. 7, 2019; or any one of the liners shown and described with respect to FIGURES 1 through 31 herein. These and related helmet or headgear liners are marketed under the trademark Fluid Displacement Liner™ technology by Kirsh Helmets Inc. In other aspects, headgear liner 316 may be any headgear or helmet liner adapted to be received by a helmet shell, such as, helmet shell 312, or a bump cap, among other protective headgear.

[00164] In order to facilitate disclosure of the invention, in FIGURES 32 and 33, helmet shell 312 is shown transparent to allow illustration of the liner assembly 314 and its components positioned within helmet shell 312. However, as is typical in the art, helmet shell 312 may typically be opaque, and be tinted, for example, with an aesthetically appealing color or design, though shell 312 maybe transparent or translucent. Helmet shell 312 may typically be made of plastic, for example, a polycarbonate, such as, a polycarbonate shell fabricated by injection molding, or an equivalent process. In one aspect, helmet shell 312 may comprise one of the helmets or helmet shells shown in US Design Patents 844,252; 853,038; 877,986; and 869,778, which are included by reference herein.

[00165] According to aspects of the invention, helmet assembly 310 includes some form of mechanism, device, or means for reducing the friction between helmet shell 312 and headgear liner 316. Specifically, aspects of the invention include some form of mechanism, device, or means for reducing the friction between internal surface 318 of helmet shell 312 and the external surface 320 of headgear liner 316. In one aspect, the device for reducing the friction may comprise any interface, interfaces, structure, or structures positioned between internal surface 318 of helmet shell 312 and the external surface 320 of headgear liner 316. In one aspect, the friction-reducing interface, interfaces, structure, or structures may extend over at least a portion of internal surface 318 and/or over at least a portion of external surface 320. In another aspect, the friction-reducing interface, interfaces, structure, or structures may extend over a substantial portion (for example, more than 50% of the surface area) of internal surface 318 and/or over a substantial portion of external surface 320. In another aspect, the friction-reducing interface, interfaces, structure, or structures may extend substantially completely over (for example, more than 80% of the surface area) internal surface 318 and/or substantially completely over external surface 320.

In one aspect, the interface, interfaces, structure, or structures between internal surface 318 of helmet shell 312 and the external surface 320 of headgear liner 316 may comprise a material characterized by providing reduced friction, for example, a polytetrafluoroethylene (PTFE), such as, a DuPont Teflon® PTFE, or its equivalent, or a Saint-Gobain Rulon® PTFE, or its equivalent.

[00166] In is envisioned that aspects of the invention may provide at least 5% reduction in friction, for example, at least a 5% reduction in the coefficient of friction (static or dynamic) between internal surface 318 of helmet shell 312 and the external surface 320 of headgear liner 316. However, it is envisioned that aspects of the invention may provide at least a 10% reduction in coefficient of friction, or at least a 20% reduction in the coefficient of friction between internal surface 318 of helmet shell 312 and the external surface 320 of headgear liner 316.

[00167] In one aspect of the invention, the reduction in the coefficient of friction may be provided by a fluid, for example, an oil-based lubricant or the like. In another aspect of the invention, the reduction in the coefficient of friction may be provided by a solid, for example, a graphite powder and the like. [00168] In one aspect, the internal surface 318 of helmet shell 312, the external surface 320 of headgear liner 316, or both may be treated, for example, chemically or mechanically to enhance the reduction in friction between the mating surfaces. For example, the internal surface 318 of helmet shell 312, the external surface 320 of headgear liner 316, or both may be sanded or polished to provide reduced friction. In another aspect, the internal surface 318 of helmet shell 312, the external surface 320 of headgear liner 316, or both maybe coated with the friction reducing compound, such as, a PTFE-containing compound, or the like.

[00169] In one aspect of the invention, as shown in FIGURE 33, at least one, but typically a plurality of interface elements or “pads” 322 maybe provided to provide at least some reduction in friction between internal surface 318 of helmet shell 312 and the external surface 320 of headgear liner 316. FIGURE 34 is an exploded perspective view of the headgear liner assembly 314 shown in FIGURE 33 with interface elements or pads 322 isolated from the liner 316. As shown in FIGURES 33 and 34, headgear liner 316, for example, a fluid-filled headgear liner may have a plurality of through holes 324, such as, any one of the liners shown and described with respect with FIGURES 1 through 31. Headgear liner 316 may also have a plurality of radial slots 326 allowing the liner 316 to conform to, for example, manipulated and positioned into, the internal shape of helmet shell 312.

[00170] As shown in FIGURE 33, in one aspect, interface elements or pads 322 may be positioned on surface 320 of headgear liner 316 where the pads 322 at least partially cover or bridge a radial slot 326 in liner 316. In one aspect, pads 322 maybe mounted or fixed, for example, with an adhesive, to one side of a radial slot 326 while not being fixed or mounted to the other side of radial slot 326. For example, in one aspect, a pad 322 maybe mounted to a surface on one side of a radial slot 326 while also being allowed to “float” or slide with little or no restriction on the surface of the opposite other side of slot 326. It is envisioned that allowing at least a portion of pad 322 to float, permits the pad 322 to be minimally affected by any separation or relative movement of the surfaces adjacent slot 326 and without deflecting, stretching, or stressing pad 322. In one aspect of the invention, pads 322 maybe fabricated from an elastic material, for example, one or more of the plastics, rubbers, or elastomers disclosed herein, and thus accommodate any relative movement of surfaces adjacent slots 326.

[00171] The interface elements or pads 322 may be mounted to the internal surface 318 of helmet shell 312, to the external surface 320 of headgear liner 316, or to both surfaces 318 and 320. Pads 322 may be mounted to the internal surface 318 of helmet shell 312 or to the external surface 320 headgear liner 316 with an adhesive, one or more mechanical fasteners, stitching, or thermal fusion (for example, welding), and the like. In one aspect, interface elements or pads 322 may not be fixed to either surface 318 or surface 316 but be allowed to “float” between surfaces while providing the desired reduction in friction.

[00172] Interface elements or pads 322 may comprise a broad range of materials and material surface textures. For example, in one aspect, pads 322 may comprise a plastic, for example, a polyamide (PA), for example, nylon; a polyethylene (PE), both high-density polyethylene (HDPE) and low-density polyethylene (LDPE); a polyethylene terephthalate (PET); a polypropylene (PP); a polyester (PE); a polytetrafluoroethylene (PTFE); a polystyrene (PS); an acrylonitrile butadiene styrene (ABS); a polycarbonate (PC); or a polyvinylchloride (PVC); among other plastics. In another aspect, pads 322 may comprise an elastic material, such as, a rubber or an elastomer, for example, a natural polymer, such as, polyisoprene rubber, or a synthetic polymer, such as, a neoprene, a thermoplastic elastomer, a thermoplastic rubber, and a polyvinyl chloride, or an ethylene propylene diene monomer (EPDM) rubber, and the like. In another aspect, pads 322 may comprise a wood (for example, in the form of paper) or a metal, while providing the desired reduction in friction.

[00173] In one aspect, pads 322 may provide a substantially smooth surface against the mating or opposing surface. In another aspect, pads 322 may provide an irregular surface, for example, one with projections, undulations, asperities, or “hills and valleys,” for instance, providing isolated points or regions of contact with the mating or opposing surface.

[00174] In the aspect of the invention shown in FIGURE 34, interface elements or pads 322 maybe flexible or pliant, for example, readily conforming to the shape and texture of the internal surface 318 of helmet shell 312 and/ or the external surface 320 of headgear liner 316. In one aspect, pads 322 may comprise a woven or unwoven fabric, for example, a natural fabric such as, cotton or wool, or a synthetic fabric, for example, fabricated from threads of any one or more of the plastics or polymers disclosed herein.

[00175] In one aspect, pads 322 may be fabricated from hook-and-loop-type fastener materials, for example, a Velcro® hook-and-loop-type fastener material. In one aspect, the hook-and-loop-type fastener material maybe mounted to internal surface 318 of helmet shell 312 and/or to external surface 320 of headgear liner 16 wherein either the ’’loop-side” or the “hook side” of the hook- and-loop-type material may bear against the opposing surface. For example, in one aspect, pads 322 may comprise hook-and-loop-type fastener material where the pad 322 maybe mounted to the external surface 320 of headgear liner 316 where either the loop side or the hook side may bear against the opposing internal surface 320 of the helmet shell 312. In one aspect, pads 322 maybe mounted to the external surface 320 of headgear liner 316 where the hook side of the hook-and-loop-type fastener may bear against the opposing internal surface 320 of the helmet shell 312. In one aspect, pads 322 may comprise a hook-and- loop-type fastener material comprising opposing “hook side” and “loop side,” where one side provides a mounting to the surface 318 or surface 320 (via a corresponding hook-and-loop-type fastener mounted to surface 318 or surface 320) and the opposing side provides the friction-reducing bearing surface against surface 318 or surface 320, as appropriate. Alternative arrangements of the mounting of ’’loop-side” or the “hook side” of a hook-and-loop-type material to internal surface 318 and/or external surface 320 maybe apparent to those of skill in the art.

[00176] FIGURE 35 is a plan view of one interface element 322 shown in FIGURE 34 according to one aspect of the invention and FIGURE 36 is a side elevation view of the interface element 322 shown in FIGURE 35. In one aspect of the invention, interface element or pad 322 may assume a broad range of geometric shapes while providing the desired reduction in friction. These shapes include circular, rectangular, square, elliptical, or any conventional polygonal shape.

[00177] In the aspect of the invention shown in FIGURES 35 and 36, pad 322 is shown in a general rounded rectangular shape or “race track oval” type shape. As shown in FIGURE 35, pad 322 may have a dimension, that is, a length, width, or diameter 328, ranging from 0.25 inches to 12 inches, depending, among other things, upon the size of liner 316, but typically has a dimension 328 ranging between 1 inch and 3 inches.

[00178] As shown in FIGURE 36, pad 22 may typically have rounded ends 329, though in other aspects, the ends 329 may not be rounded, and a thickness 330. The thickness 330 of pad 322 may range from 0.0625 inches to 2 inches, depending, among other things, upon the size of liner 316, but typically thickness 330 ranges between 0.125 inches and 0.5 inches.

[00179] In one aspect of the invention, as shown in FIGURE 36, pad 322 may comprise two components 332 and 334 mated along an interface 336 (shown by s dashed line). Components 332 and 334 maybe substantially the same material or different materials. In one aspect, interface 336 may comprise an adhesive mating the components 332 and 334.

[00180] In one aspect, components 332 and 334 may each comprise a hook-and - loop-type fastener material, for example, the same or a different hook-and-loop - type fastener material. For instance, in one aspect, components 332 and 334 may comprise a “hook side,” a “loop side,” or both of a hook-and-loop-type faster material, wherein the interface 336 comprises the backing adhesive that may typically be provided with hook-and-loop-type fasteners. In one aspect, interface elements or pads 322 may comprise components 332 and 334 each having a “hook side” surface of the hook-and-loop-type fastener while mated along interface 336 thus exposing the “hook side” surface on either side of pads 322 for bearing against and reducing friction with a mating surface. In one aspect, the dual component pad 322 shown in FIGURE 36 maybe mounted to surface 318 and/or surface 320 with an adhesive, a mechanical fastener, and/or a corresponding hook-and-loop-type faster mounted to surface 318 and/ or surface 320.

[00181] The hook-and-loop-type fasteners used for pad 322 may comprise a plastic hook-and-loop-type fastener, for example, a nylon hook-and-loop-type fastener, or a hook-and-loop type fastener made of any one of the plastics disclosed herein. In one aspect, the hook-and-loop type fastener used for pad 322 maybe a Velcro® brand hook-and-loop-type fastener provided by Velcro, USA, for example, a nylon loop Velcro® hook-and-loop-type fastener having model number 158505, or its equivalent.

[00182] As disclosed herein, helmets, headgear, headgear liners, helmet liner assemblies, and methods of protecting the head are provided that enhance head protection and provide improvements over the existing helmet or headgear technology. Aspects of the invention may include friction reducing interface elements or pads.

[00183] Though aspects of the invention may be applicable for use for construction helmets, in other aspects, the liners and helmets disclosed herein may be used an any type of helmet or headgear that would benefit from aspects of the invention. The liner’s disclosed herein may be used in any one or more of a baseball catcher’s helmet, a baseball batter’s helmet, a soft ball catcher’s helmet, a softball batter’s helmet, a hockey helmet, a hockey goalie mask, a motorcycle helmet, a motor cross helmet, a skiing helmet, a snowboarding helmet, a skateboarding helmet, a lacrosse helmet, a bicycle helmet, a jockey helmet, an official’s helmet, a medical protection helmet, a rock or ice climbing helmet, a mountain climbing helmet, a football helmet, and a military helmet, among others. Other aspects of the invention maybe used for other forms of impact protection, for example, for kneepads, for shoulder pads, for chest protectors, or shin guards, among other devices. In one aspect, any one of the liners disclosed herein may be incorporated into an impact protection device, for example, having a liner as disclosed herein and/ or having a liner disclosed herein with a shell, for example, a hard plastic shell.

[00184] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/ or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/ or groups thereof.

[00185] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiment was chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.

[00186] While several aspects of the present invention have been described and depicted herein, alternative aspects may be effected by those skilled in the art to accomplish the same objectives. Accordingly, it is intended by the appended claims to cover all such alternative aspects as fall within the true spirit and scope of the invention.

* * * * *

Claims

1. An impact dissipating headgear liner (10) comprising: a plurality of flexible, fluid impermeable enclosures (26, 28, 30, 32, 34), each of the enclosures having opposing end walls (16,18), a sidewall (20) extending between the opposing end walls; and a fluid (14) contained in each of the plurality of enclosures; wherein each of plurality of flexible, fluid impermeable enclosures (26, 28, 30, 32, 34) is in fluid communication with at least one of the other enclosures via a passage comprising a restriction (50) between the enclosures.

2. The headgear liner as recited in claim 1, wherein the liner (10) further comprises a plurality of cavities (40) extending between the upper end wall (16) and the lower end wall (18) of each of the plurality of enclosures.

3. The headgear liner as recited in claim 2, wherein the liner further comprises a cavity sidewall extending from the upper end wall (16) to the lower end wall (18) of each of the plurality of cavities.

4. The headgear liner as recited in any one claims 1 to 3, wherein the restriction (50) at least partially restricts flow of the fluid between the enclosures.

5. The headgear liner as recited in any one claims 1 to 3, wherein the restriction (50) comprises a width (w) less than a width (W) of the enclosures.

6. The headgear liner as recited in any one claims 1 to 3, wherein the restriction (50) comprises a width (w) less than 3 times a height (h) of the restriction.

7. The headgear liner as recited in any one claims 1 to 3, wherein the passage is devoid of cavities extending between the upper end wall (16) and the lower end wall (18).

8. The headgear liner as recited in any one claims 1 to 3, wherein each of the plurality of flexible, fluid impermeable enclosures (26, 28, 30, 32, 34) is cylindrical.

9. The headgear liner as recited in claim 8, wherein each of the plurality of flexible, fluid impermeable cylindrical enclosures (26, 28, 30, 32, 34) is circular cylindrical.

10. The headgear liner as recited in any one claims 1 to 3, wherein one of the plurality of flexible, fluid impermeable enclosures (26, 28, 30, 32, 34) comprises a central enclosure (26) and at least one of the plurality of the flexible, fluid impermeable enclosures (28, 30, 32, 34) comprises at least one peripheral enclosure in fluid communication with the central enclosure via the passage comprising the restriction (50).

11. The headgear liner as recited in claim 10, wherein the at least one peripheral enclosure (28, 30, 32, 34) in fluid communication with the central enclosure (26) via the passage comprises a plurality of peripheral enclosures in fluid communication with the central enclosure.

12. The headgear liner as recited in claim 10, wherein the central enclosure (26) and the peripheral enclosures (28, 30, 32, 34) are adapted to conform to the shape of an interface (64) with an internal surface of a helmet shell (62).

13. The headgear liner as recited in any one claims 10 to 12, wherein the at least one peripheral enclosure (28, 30, 32, 34), comprises a plurality of radially extending enclosures (28, 30, 32, 34), from the central enclosure (26).

14. The headgear liner as recited in claim 11, wherein the plurality of radially extending enclosures (28, 30, 32, 34), comprise divergent sidewalls.

15. The headgear liner as recited in any one claims 1 to 3, wherein the fluid (14) comprises a liquid.

16. The headgear liner as recited in claim 15, wherein the liquid comprises a liquid polydimethylsiloxane.

17. The headgear liner as recited in claim 16, wherein the liquid polydimethylsiloxane comprises a CHT QM Diluent.

18. The headgear liner as recited in claim 16, wherein the liquid polydimethylsiloxane comprises a viscosity of at least 1000 cps.

19. The headgear liner as recited in claim 16, wherein the liquid polydimethylsiloxane comprises a viscosity of at least 2000 cps.

20. The headgear liner as recited in claim 16, wherein the liquid polydimethylsiloxane comprises a viscosity of at least 3000 cps.

21. The headgear liner as recited in claim 16, wherein the liquid polydimethylsiloxane comprises a viscosity of at least 4000 cps.

22. The headgear liner as recited in claim 16, wherein the liquid polydimethylsiloxane comprises a viscosity of at least 5000 cps.

23. The headgear liner as recited in claim 1, wherein the plurality of flexible, fluid impermeable enclosures (26, 28, 30, 32, 34) comprises a synthetic amorphous silica.

24. The headgear liner as recited in claim 23, wherein the synthetic amorphous silica comprises a CHT True Skin® synthetic amorphous silica.

25. The headgear liner as recited in any one claims 1 to 3, wherein the headgear liner (10) comprises a liner for at least one of a baseball catcher’s helmet, a baseball batter’s helmet, a soft ball catcher’s helmet, a softball batter’s helmet, a hockey helmet, a hockey goalie mask, a motorcycle helmet, a motor cross helmet, a skiing helmet, a snowboarding helmet, a skateboarding helmet, a lacrosse helmet, a bicycle helmet, a jockey helmet, an official’s helmet, a medical protection helmet, a rock or ice climbing helmet, a mountain climbing helmet, a football helmet, a construction helmet, and a military helmet.

26. A helmet having the headgear liner (10) recited in any one of claims 1 to

25·

27. The helmet as recited in claim 26 wherein the helmet comprises a helmet shell (62) containing the headgear liner (10).

28. An impact protection liner (10) comprising the headgear liner recited in any one of claims 1 to 25.

29. The impact protection liner as recited in claim 28, wherein the impact protection liner comprises at least one of a kneepad, a shoulder pad, a chest protector, and a shin guard.

30. A bump cap having the impact dissipating headgear liner (10) recited in any one of claims 1 to 25.

31. The headgear liner (10, 16) ) as recited in any one of claims 1 to 25, further comprising a headgear liner retainer (114) comprising: a head strap (118) adapted to engage the head of a user and mount to a headgear (112); and at least one projection (124, 126, 128, 130) extending from the head strap 118), the at least one projection positioned and sized to engage at least one recess (134, 1-36, 138, 140) in the headgear liner (10, 116); wherein the engagement of the at least one projection (124, 126, 128, 130) with the at least one recess (134, 136, 138, 140) in the headgear liner at least partially retains the headgear liner in the headgear.

32. The headgear liner as recited in claim 31, wherein the at least one projection (124, 126, 128, 130) comprises a plurality of projections, each of the plurality of projections positioned and sized to engage at least one recess (134, 136, 138, 140) in the headgear liner.

33. The headgear liner as recited in claim 31 or claim 32, wherein the at least one projection (124, 126, 128, 130) comprises a plurality of cylindrical projections.

34. The headgear liner as recited in claim 33, wherein the at least one recess (134, 1-36, 138, 140) in the headgear liner (10, 116) comprises a least one cylindrical recess, and wherein each of the plurality of cylindrical projections are sized to engage the least one cylindrical recess.

35. The headgear liner as recited in any one claims 31 to 34, wherein the at least one-projection (124, 126, 128, 130) extending from the head strap (118) comprises at least one projection removably mounted to the head strap.

36. The headgear liner as recited in any one claims 31 to 34, wherein the at least one recess (134, 136, 138, 140) in the headgear liner (10, 116) comprises at least one recess in an extension (129) of the headgear.

37. The headgear liner as recited in any one claims 31 to 34, wherein the at least one recess (134, 136, 138, 140) in the headgear liner (10, ii6)comprises at least one recess in each of the plurality of enclosures (142).

38. The headgear liner as recited in any one claims 31 to 34, wherein the at least one projection (124, 126, 128, 130) extending from the head strap (118) comprises at least one projection removably mounted to the head strap by one of rotation and translation.

39. The headgear liner retainer as recited in any one claims 31 to 34, wherein the at least one projection (124, 126, 128, 130) extending from the head strap (118) comprises at least one projection extending radially inward or radially outward from the head strap (118).

40. The headgear liner as recited in any one claims 1 to 3, wherein the headgear liner (10, 116, 316) further comprises at least one interface element (322) positioned between the external surface (320) of the headgear liner and an internal surface (318) of a helmet shell, the at least one interface element (322) providing at least some reduction in friction between the external surface (320) of the headgear liner and the internal surface (318) of the helmet shell.

41. The headgear liner as recited in claim 40, wherein the at least one interface element (322) comprises one or more of a metal and a plastic.

42. The headgear liner as recited in claim 40 of claim 41, wherein the at least one interface element (322) comprises a plurality of interface elements mounted to one of the internal surface (318) of the helmet shell and the external surface (320) of the headgear liner.

43. The headgear liner as recited in any one of claims 40 to 42, wherein the at least one interface element (322) comprises a flexible material.

44. The headgear liner as recited in claim 43, wherein the flexible material is mounted to the external surface (320) of the headgear liner.

45 The headgear liner as recited in claim 44, wherein the flexible material is mounted to the external surface (320) of the headgear liner by at least one of an adhesive, a mechanical fastener, and stitching.

46. The headgear liner as recited in any one of claim 40 to 45, wherein the at least one interface element (322) comprises a hook-and-loop-type fastener.

47. The headgear liner as recited in claim 46, wherein the at least one interface element (322) comprises the hook-and-loop-type fastener is mounted to the external surface (320) of the headgear liner.

48. The headgear liner as recited in claim 46 or claim 47, wherein the at least one interface element (322) comprises two opposing loop sides of hook-and-loop- type fasteners.

49. A headgear liner retainer (114) comprising: a head strap (118) adapted to engage the head of a user and mount to a headgear (112); and at least one projection (124, 126, 128, 130) extending from the head strap (118), the at least one projection positioned and sized to engage at least one recess (134, 136, 138, 140) in a headgear liner (116); wherein the engagement of the at least one projection (124, 126, 128, 130) with the at least one recess (134, 136, 138, 140) in the headgear at least partially retains the headgear liner (116) in the headgear (112).

50. The retainer as recited in claim 49, wherein the at least one projection (124, 126, 128, 130) comprises a plurality of projections, each of the plurality of projections positioned and sized to engage at least one recess (134, 136, 138, 140) in a headgear liner.

51. The retainer as recited in claim 49, wherein the at least one projection (124, 126, 128, 130) comprises a plurality of cylindrical projections.

52. The retainer as recited in claim 51, wherein the at least one recess (134,

136, 138, 140) in the headgear liner (116) comprises a least one cylindrical recess, and wherein each of the plurality of cylindrical projections (124, 126, 128, 130) are sized to engage the least one cylindrical recess.

53. The retainer as recited in any one of claims 49 to 52, wherein the headgear liner (10, 116) comprises a fluid-filled headgear liner and wherein the at least one recess (134, 136, 138, 140) in the fluid-filled headgear liner comprises at least one cavity in the fluid-filled headgear liner.

54. The retainer as recited in claim 53, wherein the at least one cavity in the fluid-filled headgear liner comprises at least one through hole in the fluid-filled headgear liner.

55. The retainer as recited in any one of claims 49 to 52, wherein the at least one-projection (124, 126, 128, 130) extending from the head strap (118) comprises at least one projection removably mounted from the head strap.

56. The retainer as recited in any one of claims 49 to 52, wherein the at least one recess (134, 136, 138, 140) in the headgear liner (116) comprises at least one recess (240) in an extension (238) of the headgear liner.

57. The retainer as recited in any one of claims 49 to 52, wherein the headgear liner comprises a plurality of enclosures (142) and the at least one recess (134, 136, 138, 140) in the headgear liner (116) comprises at least one recess in each of the plurality of enclosures.

58. The retainer as recited in any one of claims 49 to 52, wherein the at least one projection (124, 126, 128, 130) extending from the head strap (118) comprises at least one projection removably mounted to the head strap by one of rotation and translation.

59. A helmet liner assembly comprising: a helmet liner (10, 116) comprising a flexible, fluid impermeable enclosure (142) having opposing end walls (16, 18), a sidewall extending between the opposing end walls, a fluid (14) contained in the enclosure (142), and at least one recess (134, 136, 138, 140) in the flexible, fluid impermeable enclosure (142); and a helmet liner retainer (114) comprising a head strap (118) adapted to engage the head of a user and mount to a headgear (112), and at least one projection (124, 126, 128, 130) extending from the head strap (118), the at least one projection (124, 126, 128, 130) positioned and sized to engage the at least one recess (134, 136, 138, 140) in the flexible, fluid impermeable enclosure of the helmet liner; wherein the engagement of the at least one projection (124, 126, 128, 130) with the at least one recess (134, 136, 138, 140) in the headgear at least partially retains the headgear liner in the headgear.

60. The helmet liner assembly as recited in claim 59, wherein the at least one projection (124, 126, 128, 130) comprises a plurality of projections, each of the plurality of projections positioned and sized to engage the at least one recess (134, 1-36, 138, 140) in the helmet liner.

61. The helmet liner assembly as recited in claim 59 or claim 60, wherein the at least one projection (124, 126, 128, 130) extending from the head strap (118) comprises a plurality of cylindrical projections extending from the head strap.

62. The helmet liner assembly as recited in claim 60 or claim 61, wherein the at least one recess (134, 136, 138, 140) in the helmet liner (10, 116) comprises a least one cylindrical recess, and wherein each of the plurality of cylindrical projections are sized to engage the least one cylindrical recess.

63. The helmet liner assembly as recited in any one of claims 59 to 62, wherein the at least one recess in the flexible, fluid impermeable enclosure (142) comprises at least one cavity in the flexible, fluid impermeable enclosure.

64. The helmet liner assembly as recited in claim 63, wherein the at least one cavity in the flexible, fluid impermeable enclosure comprises at least one through hole in the flexible, fluid impermeable enclosure.

65. The helmet liner assembly as recited in any one of claims 59 to 62, wherein the at least one projection (124, 126, 128, 130) extending from the head strap (118) comprises at least one projection removably mounted from the head strap.

66. The helmet liner assembly as recited in any one of claims 59 to 62, wherein the at least one recess (134, 136, 138, 140) in the flexible, fluid impermeable enclosure (142) comprises at least one recess (240) in an extension (238) of the flexible, fluid impermeable enclosure.

67. The helmet liner assembly as recited in any one of claims 59 to 62, wherein the at least one recess (134, 136, 138, 140) comprises at least one recess in each of the plurality of flexible, fluid impermeable enclosures (142).

68. The helmet liner assembly as recited in any one of claims 59 to 62, wherein the at least one projection (124, 126, 128, 130) extending from the head strap (118) comprises at least one projection removably mounted to the head strap by one of rotation and translation.

69. A helmet (112) having the headgear liner assembly recited in any one of claims 59 to 68.

70. The helmet (112) as recited in claim 69, wherein the helmet comprises a construction helmet.

71. The helmet (112) as recited in claim 70, wherein the construction helmet comprises a hard hat or a bump cap.

72. The helmet (112) as recited in claim 69, wherein the helmet comprises at least one of a baseball catcher’s helmet, a baseball batter’s helmet, a soft ball catcher’s helmet, a softball batter’s helmet, a hockey helmet, a hockey goalie mask, a motorcycle helmet, a motor cross helmet, a skiing helmet, a snowboarding helmet, a skateboarding helmet, a lacrosse helmet, a bicycle helmet, a jockey helmet, an official’s helmet, a medical protection helmet, a rock or ice climbing helmet, a mountain climbing helmet, a football helmet, and a military helmet.

73. A method of protecting the head, the method comprising: mounting a helmet liner retainer (114) comprising a head strap (118) adapted to engage the head of a user and at least one projection (124, 126, 128, 130) extending from the head strap into a helmet shell (112); attaching a helmet liner (116) comprising a flexible, fluid impermeable enclosure (142) containing a fluid (14) and having at least one recess (134, 136, 138, 140) in the enclosure (142) to the helmet liner retainer (114) by inserting the at least one projection (124, 126, 128, 130) from the head strap (118) of the helmet liner retainer (114) into the at least one recess (134, 136, 138, 140) in the enclosure (142); and positioning the helmet (112) with helmet liner retainer (114) and the flexible, fluid impermeable enclosure (142) onto the head of the user.

74. A headgear assembly (310) comprising: a helmet shell (312) shaped to generally conform to the head of a wearer, the helmet shell having external surface and an internal surface (318); a headgear liner (314) shaped and adapted to be received by the helmet shell (312), the headgear liner having an external surface (320) positioned to contact the internal surface (318) of the helmet shell; and at least one interface element (322) positioned between the external surface (320) of the headgear liner and the internal surface (318) of the helmet shell, the at least one interface element (322) providing at least some reduction in friction between the external surface (320) of the headgear liner and the internal surface (312) of the helmet shell.

75. The headgear assembly (310) as recited in claim 74, wherein the at least one interface element (322) comprises one or more of a metal and a plastic.

76. The headgear assembly (310) as recited in claim 74 or claim 75, wherein the at least one interface element (322) comprises a plurality of interface elements mounted to one of the internal surface of the helmet shell and the external surface of the headgear liner.

77. The headgear assembly (310) as recited in any of claims 74 to 76, wherein the at least one interface (322) element comprises a flexible material.

78. The headgear assembly (310) as recited in claims 77, wherein the flexible material is mounted to the external surface of the headgear liner.

79. The headgear assembly (310) as recited in claim 76 or claim 77, wherein the flexible material is mounted to the external surface of the headgear liner by at least one of an adhesive, a mechanical fastener, and stitching.

80. The headgear assembly (310) as recited in any one of claims 74 to 79, wherein the headgear liner comprises a flexible, fluid impermeable enclosure having opposing end walls, a sidewall extending between the opposing end walls, and a fluid contained in the enclosure.

81. The headgear assembly (310) as recited in claim 80, wherein the at least one interface element (322) comprises a hook-and-loop-type fastener.

82. The headgear assembly (310) as recited in claim 81, wherein the at least one interface element (322) comprises the hook-and-loop-type fastener is mounted to the external surface of the headgear liner.

83. The headgear assembly (310) as recited in claim 80 or claim 81, wherein the at least one interface element (322) comprises two opposing loop sides of hook-and-loop-type fasteners.

84. The headgear assembly (310) as recited in any one of claims 74 to 83, wherein the headgear comprises a helmet.

85. The headgear as recited in claim 84, wherein the helmet comprises at least one of a baseball catcher’s helmet, a baseball batter’s helmet, a soft ball catcher’s helmet, a softball batter’s helmet, a hockey helmet, a hockey goalie mask, a motorcycle helmet, a motor cross helmet, a skiing helmet, a snowboarding helmet, a skateboarding helmet, a lacrosse helmet, a bicycle helmet, a jockey helmet, an official’s helmet, a medical protection helmet, a rock or ice climbing helmet, a mountain climbing helmet, a football helmet, a hardhat, and a military helmet.

86. A headgear liner assembly comprising: a headgear liner (314) comprising a flexible, fluid impermeable enclosure (10, 116, 142, 316) having opposing end walls (16,18), external surfaces (320) on the opposing end walls, a sidewall extending between the opposing end walls, and a fluid (14) contained in the enclosure; and at least one interface element (322) mounted to the headgear liner (314), the at least one interface element providing at least some reduction in friction between the headgear liner (314) and an internal surface (318) of a helmet shell (312) into which the headgear liner is positioned.

87. The headgear liner assembly as recited in claim 86, wherein the at least one interface element (322) comprises a plurality of interface elements mounted to the external surface of the headgear liner.

88. The headgear liner assembly as recited in claim 86 or claim 87, wherein the at least one interface element (322) comprises a flexible material.

89. The headgear liner assembly as recited in claim 88, wherein the flexible material is mounted to the external surface of the headgear liner.

90. The headgear liner assembly as recited in claim 88 or claim 89, wherein the flexible material is mounted to the external surface of the headgear liner by at least one of an adhesive, a mechanical fastener, and stitching.

91. The headgear liner assembly as recited in any one of claims 86 to 90, wherein the at least one interface element (322) comprises a hook-and-loop-type fastener.

92. The headgear liner assembly as recited in claim 91, wherein the at least one interface element (322) comprises the hook-and-loop-type fastener is mounted to the external surface of the headgear liner.

93. The headgear liner assembly as recited in any one of claims 86 to 90, wherein the at least one interface element (322) comprises two opposing loop sides of a hook-and-loop-type fasteners.

94. A helmet (111) having the headgear liner (314) recited in any one of claims 86 to 93.

95. A method of protecting the head, the method comprising: mounting at least one interface element (322) to one of an external surface (320) of a headgear liner (314) and an internal surface (318) of a helmet shell (312), the at least one interface element (322) providing at least some reduction in friction between the one of the external surface of the headgear liner and the internal surface of the helmet shell; inserting the headgear liner (314) into the helmet shell (312) where the at least one interface element (322) is positioned between the external surface (320) of the headgear liner and the internal surface (318) of the helmet shell; and positioning the helmet shell (312) with headgear liner (314) and the at least one interface element (322) onto the head of a user.