Patent Description:
The invention may also or alternatively relate generally to visor assemblies that comprise an overlay-sheet and a shield-visor, which overlay-sheet and shield-visor are releasably attached to one another; and a kit of parts for constructing such a visor assembly.

The invention may also or alternatively generally relate to a visor,
particularly an overlay-visor, for use in a visor assembly in which an overlay-visor and a shield-visor are releasably attached to one another.

The visors and visor assemblies of the invention are particularly useful for personal protection equipment for facial and eye protection. Examples of preferred personal protection equipment include motorbike helmets, motorbike style helmets such as quad-bike, snowmobile, racing car and skiing helmets; heavy-duty protective visors, for example, ballistic face shields which may be used in riot helmets and visors for use by the emergency services; and/or goggles such as underwater diving goggles, motorcycle goggles or skiing goggles.

Visor assemblies comprising a shield-visor with an overlay-visor releasably attached thereto by mechanical fastenings, are known.

In such visor assemblies the shield-visor is more substantial than the overlay-visor and acts as a shield. In the case of motorbike style helmets the shield-visor acts to protect a user's face from wind, rain, dirt and grit; and in the case of ballistic visors it acts to protect the user's face from more substantial projectiles and blows. In goggles the shield-visor tends to be limited to extending over the eyes and that part of face immediately adjacent the eyes. The shield-visor of the goggles may have different functions depending on usage. For example, diving goggles are worn to aid underwater vision, motorcycle goggles are worn to protect a user's eyes from projectiles and dirt, and ballistic goggles are worn to protect a user's eyes from more substantial projectiles. Goggles may be provided with two shield-visors, one per eye.

Shield-visors may be provided in <NUM>-dimensional (<NUM>-D) form, that is occupying a single plane so as to be flat; <NUM>-dimensional (<NUM>-D) form, that is curved in one direction; or <NUM>-dimensional (<NUM>-D) form, that is curved in two directions so as to be bowled. Overlay-visors may be provided in appropriate shapes to fit to the surfaces of these various shield-visor forms. In this respect, overlay-visors may also be <NUM>-D, <NUM>-D or <NUM>-D. <NUM>-D overlay-visors are used with <NUM>-D shield-visors; <NUM>-D and <NUM>-D overlay-visors are used with <NUM>-D shield-visors; and <NUM>-D overlay-visors are used with <NUM>-D shield-visors.

The overlay-visor is typically utilized to provide an improved viewing window for the visor wearer. For example, the overlay-visor may be adapted to have an anti-condensation function to prevent misting-up of the viewing area. The overlay-visor may also or alternatively be provided with tinting to give improved viewing in varying light conditions. The viewing area of the shield-visor and/or the overlay-visor is the area through which the user looks.

Examples of helmet visor assemblies are known from <CIT> and <CIT>, which provide anti-condensation overlay-visors attached to shield-visors.

In <CIT>, prevention of misting-up of the viewing area is preferably achieved by provision of a chamber between an inner overlay-visor and a shield-visor. The chamber is filled with air or gas and acts to thermally insulate the internal surface of the overlay-visor from the external environment. The chamber is created by the provision of a flexible seal adhered to the overlay-visor and fitted detachably against the shield-visor so that the seal forms the peripheral boundary of the chamber. For the best anti-condensation results the chamber is sealed as far as possible with respect to the environment to prevent ingress of moisture and dirt to the chamber. In the preferred embodiment of <CIT> the seal is formed from a bead of silicone material adhered to the overlay-visor.

<CIT> discloses a an overlay-visor adapted to be releasably attached to a shield-visor, as well as a method of forming such an overlay-visor. An elastomeric gasket may be applied to the distal surface of a spacer.

In a visor that is provided with a seal the viewing area is defined by the seal, which forms the boundary of the viewing area.

The visors are provided with secure yet readily releasable mechanical retention systems for retaining the overlay-visor. The visors are provided with mechanical retaining means for retaining an inner overlay-sheet. The retaining means takes the form of inwardly projecting studs against which the overlay-sheet abuts. Recesses are provided in the overlay-sheet which engage with the studs to provide a secure retention on the inside of the curved visor.

The described stud based mechanical retention mechanism is the currently predominant solution to providing good anti-misting/fogging vision in visors.

Such a system offers excellent retention of an inner overlay-sheet but suffers from the disadvantage that the mechanical retaining means in the form of the studs, must be fitted through openings in the visor. The provision of such openings requires additional processing at a manufacturing stage if the visor is manufactured for use with an overlay-sheet; or it requires skilled and accurate adaptation of a pre-existing visor in the event of retrofitting of an overlay-sheet. In both cases the situation is further complicated by considerations of how the provision of the required holes may affect the structural integrity of the visor. The integrity of the visor is of major importance, in particular in order to meet various governmental safety requirements that visors are often subjected to.

So that the overlay-visor is detachable from the shield-visor, the bead of silicone material is dry and set before it is brought into contact with the shield-visor. In this manner there is no adherence between the shield-visor and the spacer or seal so that the overlay-visor can be removed from the assembly or be replaced.

In order for such visor combinations to function effectively, the position of the mechanical retainers is critical in order to effectively tension the overlay-sheet into engagement with the visor. Any play between the components can lead to friction, irritating noise and abrasion e.g. of the viewing region of the visor. In the particular case of a visor assembly in which it is intended to form a sealed chamber between the overlay-sheet and the visor, movement of the overlay-sheet can result in loss of the seal thus allowing ingress of moisture and dirt to the chamber. If holes are drilled in order to retrofit an overlay-sheet, any inaccuracy may cause leakages by the studs or render the whole assembly to be useless. Attempts have been made to improve retention by the use of eccentric studs that may be tightened by rotation, for example, through <NUM>°.

An easy yet also reliable attachment for overlay-sheets to shield-visors, that allows detachability (i.e. non-permanent attachment) of an overlay-sheet from a shield-visor is desirable.

It is also useful if an overlay-sheet retention system can retain an over-lay on either or both of the internal and external major surfaces of a curved shield-visor. The known stud based mechanical fasteners cannot achieve this because the stud and recess system acts as a retaining means by providing a compressive tension on the overlay-sheet.

It would also be useful if a single type of overlay-sheet retention system could be used for fastening any or all of the inner and outer surfaces of a curved visor; or to a flat visor.

Shield-visors generally vary in their thickness and hence flexibility according to the use for which they are designed. For example, a motorbike helmet visor need only be thick enough to deflect fairly light weight projectiles, its thickness being kept to a minimum in order to reduce weight. Motorbike helmet visors are therefore quite flexible. A ballistic visor, however, must be thick and stiff enough to withstand impacts from heavier projectiles. A ballistic visor is therefore generally less flexible than a motorbike helmet visor. This causes problems when using the stud and recess mechanisms discussed above because in order to fit the overlay-sheet the visor must initially be flexed at least partially out of its curved state. This moves the studs away from one another and allows the recesses of the overlay-sheet to be engaged with the studs before they are allowed to move back to their original positions locking the overlay-sheet in place. The lack of flexibility in the ballistic visor makes single-handed fitting of the overlay-sheet with this retention system virtually impossible. Attempts have been made to overcome this problem by the use of eccentric studs which can be rotated into and out of engagement with the overlay-sheet recesses.

Fitting of overlay-sheets to in-flexible visors, for example visors made of glass, as in glass goggles or instrument panels; or <NUM>-D visors, also need to have retaining means which can be utilized with minimal flexing of the visor or without any flexing of the visor.

Various attempts have been made to answer the desire for replaceable overlay-sheets that do not require the addition of studs to a shield-visor.

An example is found in patent publication <CIT>, which describes the use of arrays of interlocking mushroom shaped connectors and/or magnets.

Another example is described in patent publication <CIT>, which details the use of a peripheral gasket of closed cell acrylic foam layers (such as Very High Bond, VHB of <NUM>), or a closed cell crosslinked polyethylene (such PEX or XLPE of Sekisui Alveo), or closed cell polyurethane foam, or other similar materials, with added adhesive layers. The adhesive is attenuated to allow for removal and repositioning.

It remains desirable to provide an overlay-sheet that is any one or more of readily, efficiently and economically manufacturable and fittable; reliable; with minimal visual interference or distraction in a user's viewing field. While an apparent route to answering such a problem would be to more solidly affix the inner-visor to an outer-visor, e.g. by use of bolts or screws, these solutions can be undesirable because of increased complexity and user inconvenience.

The invention provides a method; an overlay-visor; a visor assembly; a kit of parts; and a helmet in accordance with the claims.

According to an aspect of the invention, there is provided a method of forming an overlay-visor comprising a viewing area and a spacer extending along at least a portion of a periphery of the viewing area, comprising the steps of: injection molding, extruding, nozzling, beading, and/or caulking a bead of fluid elastomeric material onto a surface of the overlay-sheet to form a spacer; wherein the elastomeric material is tacky when set and/or cured. The method may be used to provide any of the overlay-visors described herein. The invention in another aspect provides overlay-visors obtainable by the method. The invention in other aspects provides visor assemblies, kits of parts, or helmets comprising such overlay-visors obtainable by the method.

According to an aspect of the invention there is provided a visor assembly, comprising a shield-visor having a surface; an overlay-visor; wherein the overlay-visor comprises a viewing area and a spacer extending along at least a portion of a periphery of the viewing area, wherein a distal surface of the spacer is tackified.

The body of the overlay-visor is preferably made of cellulose propionate, cellulose acetate, and/or cellulose triacetate. Such materials can provide good anti-misting properties.

Preferably there is no mechanical fastening of the overlay-visor to the shield-visor.

The tacky distal surface of spacer can provide for reliable yet releasable adhesion of the overlay-sheet to a surface of the shield-visor. Since the tacky distal surface is not permanently adhered to the visor the overlay-sheet is removable from the visor so that it can be replaced if damaged, or removed or replaced depending upon weather conditions, or repositioned if incorrectly positioned.

In preferred embodiments, the spacer may take the form of an elastomeric gasket.

The gasket has a tacky distal surface. The gasket is preferably permanently adhered to the overlay-sheet, and non-permanently adhered to a surface of the shield-visor via the tackified distal surface. In this manner the overlay-visor can be removed from the shield-visor so that it can be replaced if damaged, or removed or replaced depending upon weather conditions.

The gasket has a generally convex, concave, polygonal, rectangular, square, U-shaped, Z-shaped, W-shaped or multi-channeled transverse cross section.

In a preferred embodiment the gasket comprises an elastomer material. Preferably said elastomer material is a silicone or other rubber material. This type of material is elastically deformable which is advantageous for sealing and adhesion.

The elastomeric character of the gasket allows some controlled movement between the overlay-visor and shield-visor, which may be important if the overlay-sheet and the visor are made of different materials, or subject to different temperature or other environmental conditions, leading to differences in expansion and contraction or shrinkage. For example, the shield-visor may be formed of polycarbonate, while the overlay-visor can comprise a number of different materials, particularly preferred are polymeric resins. Examples of particularly preferred materials are cellulose propionate, cellulose acetate and/or cellulose triacetate.

It is preferred that the gasket material is transparent.

The term elastomer refers to a rubbery material composed of long chainlike molecules, or polymers, that are capable of recovering their original shape after being stretched to a great extent-hence the name elastomer, from "elastic polymer".

Preferably the spacer, in particular the gasket, comprises a pressure-sensitive adhesive.

Pressure-sensitive adhesives (PSAs) are elastomer polymer materials that demonstrate aggressive and permanent tackiness, so that they are able to adhere to objects with low levels of application pressure, and preferably do not require heat or activation to adhere. They are also removable without leaving a visible residue.

The gasket may be applied to the overlay-sheet by a number of techniques.

The spacer or gasket is applied to the overlay-sheet as a fluid, e. g by extrusion through a nozzle.

For example, the gasket may be applied by extrusion via a nozzle, where the gasket material is applied as a fluid that cures in situ upon the overlay-sheet. It is also possible to use an extrusion method involving extrusion of a bead of the gasket material from a nozzle onto the spacer's distal surface, for example by CNC techniques, dispensing or extrusion via nozzle or hollow needle, or caulking.

One aspect of the invention is realized in the form of a kit of parts for constructing the above visor assembly. Such a kit of parts comprises an overlay-sheet as described, and a shield visor.

The visor assembly of the present invention can conveniently be provided as a kit of parts comprising an overlay-visor as discussed above, and a shield-visor as discussed.

According to a further aspect of the invention there is provided a helmet comprising; an opaque skull protection portion; and a visor assembly as discussed above.

Specific embodiments of the invention will now be described by way of nonlimiting example only. The features and advantages of the invention will be further appreciated upon reference to the following drawings, in which:.

<FIG> shows a motorcycle helmet <NUM> comprising a 3D visor assembly <NUM> in accordance with the present invention. There is provided a visor <NUM> having releasably adhered to its inner-surface an overlay-sheet <NUM>. There are no mechanical retaining elements between the overlay-visor <NUM> and the visor <NUM>.

Also illustrated in <FIG> is a spacer <NUM> extending around the periphery of the overlay-visor <NUM>.

As a result of the presence of this spacer <NUM>, the overlay-visor <NUM> is spaced from the shield-visor <NUM> and a chamber is formed between the overlay-visor <NUM> and the shield-visor <NUM>. This chamber acts as an insulator reducing condensation formation in the viewing area of the shield-visor <NUM>. It will be clear to those skilled in the art that the spacer <NUM> may be provided at alternative locations on the overlay-visor <NUM> so long as it encompasses an adequate viewing area for the visor user. For example, the overlay-visor may be larger than the viewing area of the shield-visor but the spacer <NUM> located on the periphery of the viewing area, and thus not on the periphery of the overlay-visor <NUM>.

The spacer <NUM>, in the form of an PSA elastomeric gasket seal, is adhered to the overlay-visor <NUM> and is held in non-permanent adhesive relation to the shield-visor <NUM>. The overlay-visor <NUM> is removable from the shield-visor <NUM> so that it can be replaced if damaged or removed or replaced depending upon weather conditions.

Spacer <NUM> provides a seal between the overlay-visor <NUM> and the shield-visor <NUM>, as a result of which ingress of moisture, and consequently misting up of the shield-visor <NUM>, can be avoided.

<FIG> show partial sections through overlay-visors <NUM> provided with seal members <NUM> having tackified distal surface <NUM>.

In <FIG> the seal member <NUM> is provided on both a first surface <NUM> and a second surface <NUM> of the overlay-visor <NUM>.

In <FIG> the seal member <NUM> is applied to only a first surface <NUM> of the overlay-visor <NUM>.

In <FIG> the seal member <NUM> is provided on both a first surface <NUM> and the edge <NUM> of the overlay-visor <NUM>.

In <FIG> the seal member <NUM> is provided on the first surface <NUM> and the second surface <NUM> as well as on the edge <NUM> of the overlay-visor <NUM>.

In <FIG> the seal member <NUM> is provided on the first surface <NUM> of the overlay-visor <NUM> and is formed with a double ridge construction. Such a double ridge may be useful in providing an improved sealing of the chamber.

In <FIG> there is shown a visor assembly <NUM> in which the shield-visor <NUM> is provided with a recess <NUM>. The dimensions of the recess correspond to the external dimensions of the overlay-visor <NUM>.

The overlay-visors can be manufactured by a process in which the spacer/seal <NUM> is extruded from a nozzle or caulked onto the overlay-visor <NUM>.

The overlay-visors can be manufactured by a process in which the spacer/seal <NUM> is injection molded directly onto the overlay-visor <NUM>, which does not form part of the claimed invention. In such a process use is made of a mold <NUM>. Partial cross-sections of a mold are shown in <FIG>. The mold has a first cavity shaped to receive a prefabricated overlay-visor <NUM>. The mold is also provided with a second cavity which as can be seen in the figure is shaped as the inverse of the desired seal shape <NUM> and is placed in relation to the first cavity such that the seal is formed on the periphery of the viewing area of the overlay-visor <NUM>. The mold shown in <FIG> is adapted to provide a seal on both surfaces and the edge of the overlay-visor.

The over-lay visor is provided as a prefabricated component and is either cut or milled from an extruded sheet; or is injection molded.

In an alternative embodiment (not shown) a multi-component injection molding process is used to form the overlay-visor. In this process the overlay-visor is injection molded into the same mold in which the seal is formed.

Alternative shapes to those shown in <FIG> of the second cavity of the mold are used to provide alternative seal shapes and cross-sections, examples of which are shown in <FIG>.

In a non-claimed alternative (not shown) a seal <NUM> or spacer may be provided on the shield-visor rather than on the overlay-visor. Similarly, to the overlay-visor the seal may be provided by injection molding onto a prefabricated shield-visor or by multi-component injection molding of the shield-visor and seal or spacer.

In such an example an overlay-visor not provided with a seal or spacer is placed over the seal to create an insulating gap or chamber. Hence a similar anti-misting effect can be achieved as with the above described embodiments. However, this embodiment is less preferred because on suffering damage to the spacer or seal the shield-visor must be discarded. Since the shield-visor is typically more expensive than the overlay-visor, it is preferred that in the event of damage to the seal it is the overlay-visor that is discarded.

<FIG>, illustrate the overlay-sheet preapplication and post-application to the shield-visor respectively.

<FIG>, show partial sections through overlay-visors <NUM> provided with integrally formed spacers <NUM>, the spacer <NUM> carries a gasket <NUM> of tackified elastomeric material upon a distal surface <NUM> such that the gasket <NUM> is positioned between the spacer <NUM> and the inner surface of the shield-visor <NUM> when adhered in place.

The overlay-visor <NUM> is a single-piece element including the part that is the viewing area and its spacer <NUM>. That is, the overlay visor <NUM> is integrally formed as single-piece element.

In <FIG> overlay-visor <NUM> is provided with an integrally formed U-shaped cross section spacer <NUM> with an elastomer gasket <NUM> applied to its distal surface <NUM>. The spacer <NUM> diverts out of the major plane of the overlay-visor <NUM>. The spacer <NUM> extends out of a first surface <NUM> of the overlay-visor. In use, the first surface <NUM> of the overlay-visor <NUM> faces a user's face, and a second surface <NUM> opposite thereto, faces an inner surface of the shield-visor.

In <FIG> overlay-visor <NUM> is provided with an integrally formed Z-shaped cross section spacer <NUM> with an elastomer gasket <NUM> applied to its distal surface <NUM>.

In <FIG> overlay-visor <NUM> is provided with an integrally formed W-shaped cross section spacer <NUM> with an elastomer gasket <NUM> applied to its distal surface <NUM>.

In <FIG> overlay-visor <NUM> is provided with an integrally formed double concave channel cross section, with a gasket <NUM> applied to its distal surface <NUM>.

In the cross sections of <FIG>, the material of the overlay visor <NUM> diverts out of its major plane at the position of the spacer <NUM>. The spacer <NUM> may be obtained by deforming, preferably thermoforming and/or molding, a sheet material.

Many modifications in addition to those described above may be made to the structures and techniques described herein without departing from the scope of the invention. Accordingly, although specific embodiments have been described, these are examples only and are not limiting upon the scope of the invention.

It should be noted that the term "comprising" as used in the claims or description of this application does not exclude other elements or steps; and the terms "a" and "an" do not exclude a plurality.

Claim 1:
A method of forming an overlay-visor (<NUM>) comprising a viewing area and a spacer (<NUM>) extending along at least a portion of a periphery of the viewing area, comprising the steps of:
- injection molding, extruding, nozzling, beading, and/or caulking a bead of fluid elastomeric material onto a surface of the overlay-sheet to form a spacer;
wherein the elastomeric material is tacky when set and/or cured; characterized in that
the elastomeric material is a polymer selected from natural rubber, acrylics, nitriles, styreneisoprene block copolymers, silicones, vinyl ethers, and butyl rubber; and
a tackifier is added to each of the polymers, wherein the tackifier is a rosin ester or a terpene resin, or an MQ silicate resin when the polymer is silicone.