Patent Application
20210219648
The invention relates generally relate to a method of manufacturing a visor, particularly an overlay-visor, such as may be used in a visor-assembly comprising an overlay-visor and a shield-visor releasably attached to one another. The invention may also relate to an apparatus for implementing such a method; a visor, particularly an overlay-visor, obtained from the method of the invention; and a visor assembly comprising a visor obtained from the method of the invention.
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 1-dimensional (1-D) form, that is occupying a single plane so as to be flat; 2-dimensional (2-D) form, that is curved in one direction; or 3-dimensional (3-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 1-D, 2-D or 3-D. 1-D overlay-visors are used with 1-D shield-visors; 1-D and 2-D overlay-visors are used with 2-D shield-visors; and 3-D overlay-visors are used with 3-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 U.S. Pat. Nos. 5,765,235 and 6,922,850, the contents of which are hereby incorporated by reference in their entirety, which provide anti-condensation overlay-visors attached to shield-visors.
In U.S. Pat. No. 6,922,850, 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 U.S. Pat. No. 6,922,850 the seal is formed from a bead of silicone material adhered to the overlay-visor.
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 180°.
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 3-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 WO2008/096178, which describes the use of arrays of interlocking mushroom shaped connectors and/or magnets.
Another example is described in patent publication WO2011/001278, which details the use of a peripheral gasket of closed cell acrylic foam layers (such as Very High Bond, VHB of 3M), 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.
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.
According to another aspect of the invention, there is provided an overlay-visor for use in the described visor assembly. The overlay-visor is releasably attachable to a shield-visor, the overlay-visor comprising a viewing area, a spacer extending along at least a portion of a periphery of the viewing area, wherein a distal surface of the spacer is tackified, at least along a portion thereof.
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 applied to a periphery of a major planar surface of the overlay-sheet, or may comprise the combination of (preferably integrally formed) a protrusion of the overlay-sheet and an elastomeric gasket atop the protrusion forming the tackified distal surface thereof.
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.
The gasket may take the form of an elastomeric layer adhered to the distal surface of a (optionally integrally formed) projection from the overlay sheet, and acts as an interface between the overlay-visor and the shield-visor's surface.
Preferred cross-sections for the overlay-sheet projection include U-shaped, Z-shaped, and W-shaped. In the U-shaped and Z-shaped cross sections, the lower edge of the U and Z forms the distal surface of the spacer to which the gasket is applied. A W-shaped cross section is particularly advantages as it forms a concave channel at its lower edge into which the gasket material can be applied by the techniques previously discussed. While a W-shaped cross-section provides only a single channel at its distal surface, more channels may also be provided. Cross sections comprising one or more channels for receiving the gasket may generally be used.
In a preferred embodiment the spacer takes the form of a seal element that acts to form a sealed compartment between the overlay-sheet and the visor. Such a sealed compartment may act as an insulator reducing the possibility of condensation formation in the viewing area of the visor.
Preferably the seal member is permanently adhered to the overlay-sheet and non-permanently adhered to a surface of the shield-visor via the tackified distal surface. The non-permanent adherence to the shield-visor is to maintain the overlay-sheet in place and to preferably form an airtight seal but does not permanently adhere to the visor allowing for removal of the overlay-sheet for replacement if damaged or removed or replaced depending upon weather conditions.
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.
PSAs are usually formulated based on an elastomeric polymer material in combination with a tackifier resin such as a rosin ester.
The relevant balance of tackiness and peel can be obtained by varying the content ratio of an added tackifier(s).
Preferred elastomer chemistries are natural rubber, acrylics, nitriles, styrene-isoprene block copolymers, silicones, vinyl ethers, and butyl rubber. Tackifiers are added to each of these polymers to obtain tackiness. The addition of tackifiers is not necessary for acrylics, although they may optionally be included.
Exemplary elastomers include polyisoprene, the polymer constituent of natural rubber and synthetics, such as styrene-butadiene rubber, butadiene rubber, acrylonitrile- butadiene copolymer (nitrile rubber), isobutylene-isoprene copolymer (butyl rubber), polychloroprene (neoprene), polysulfide (Thiokol), polydimethyl siloxane (silicone), fluoroelastomer, polyacrylate elastomer, polyethylene (chlorinated chlorosulfonated), styrene-isoprene-styrene (SIS, styrene-butadiene-styrene (SBS) block copolymer, EPDM-polypropylene blend.
Exemplary tackifiers include rosin esters, terpene resins (C-5 and C-9 resins, low molecular weight polymers from petroleum streams).
A preferred material includes silicone polymer with added tackifiers selected from the group consisting of MQ silicate resins. MQ resins are materials obtained by reaction of monofunctional trimethyl silane (“M”) with quadrafunctional silicon tetrachloride (“Q”).
Silicone polymers demonstrate excellent weather and/or humidity resistance.
The elastomer material may advantageously include shear-thinning rheology modifiers, as this may allow easy application for manufacture (e.g. easy flow, low viscosity under shear during nozzle or injection molding) yet also maintain a desired transverse cross section until the gasket composition has set or cured (e.g. higher viscosity under low shear).
Rheology modifiers may preferably be selected from natural gums, cellulosics, alkali-soluble and alkali swellable emulsions (ASE), hydrophobically modified alkali swellable emulsions (HASE), hydrophobically modified ethoxylated urethanes (HEUR), organoclays, castor oil derivatives, polyamides, calcium sulfonate derivatives, modified polyurea, fibers, and combinations thereof.
The seal member is preferably made of silicone material, particularly transparent silicone material. This acts as a flexible seal between the overlay-sheet and visor. Moreover, any compressive strain that results because of a biasing of the overlay-sheet toward the visor is uniformly distributed. Preferably the silicone material is dry, set and flexible silicone material but the skilled person will be well aware of other alternatives that may be considered equivalent to this material.
Silicone polymers are also usefully available in a range of (uncured) fluid forms with modifiable rheology, for example modifiable viscosities
The elastomer resin used to form the spacer or seal may also preferably be a low-temperature setting resin. This advantageously allows curing to occur at temperatures that do not adversely affect the qualities of the (e.g. optical) of the overlay-visor; cause undesired size or shape changes in the visor; or adversely affect surface coatings or finishes (e.g. anti-scratch or anti-misting coatings) on the visor. Elastomeric resins are preferably selected to be curable at 90° C. or below, more preferably 70° C. or below; even more preferably 60° C. or below; and most preferably 50° C. or below.
The elastomer resin used to form the spacer or seal may also preferably be a hot-melt pressure sensitive adhesive (HMPSA). HMPSAs are heated to melt them for application and are then subsequently cooled to set or cure. Butyl rubber (BR) and polyisobutene (PIB) based HMPSA can provide flexibility at low temperature, and can impart improved chemical resistance and enhanced aging.
Hot-melt formulations may include butyl rubber, petrolatum and amorphous polypropylene, and hydrocarbon oils, polybutenes, and microcrystalline waxes (to reduce viscosity).
Preferred HMPSAs may be selected from Styrenic Block Copolymer-Based Hot-Melt Pressure-Sensitive Adhesives and/or Acrylic Block Copolymer-Based Hot-Melt Pressure-Sensitive Adhesives, including polyacrylates and poly(meth)acrylates.
The gasket may also comprise foams, preferably closed cell foams, such as closed cell acrylic foams or closed cell cross-linked polyethylene foams, or closed cell polyurethane foam, or other similar materials. To achieve adhesion of a foam gasket to the integrally formed spacer, the foam may be provided on one side with an adhesive layer.
In a preferred embodiment the gasket elastomer material has a Shore A hardness of 50-95, more preferably 60-90, even more preferably 65-80, most preferably 70. The Shore A scale is used to measure the hardness of elastomers, rubber-like materials, and elastomer materials like polyurethane. The method of Shore A hardness measurement is one using a durometer as described in standard ISO 7619-1:2010
Gaskets comprised in the spacer preferably comprise a pressure sensitive adhesive (PSA); a non-residue PSA; a tacky, elastomeric polymer; and/or an elastomeric polymer comprising tackifiers.
For embodiments of the overlay sheet comprising a peripheral protrusion upon which the gasket is applied, the protrusion may have the same material composition as the material of the viewing area or the overlay-visor. The protrusion may be integrally formed from the overlay-visor material, preferably by physical deformation, more preferably using thermoforming.
The spacer may have a constant height but may also have a height that varies along its length. This can be useful in circumstances where it is desirable for a visor assembly to have a varied spacing of the overlay-visor and the shield-visor. For example, in a motorbike helmet visor assembly it may be desirable to have a narrow spacing at the upper portion of the visor assembly and a deeper spacing at the lower portion of the visor assembly. This helps to avoid a scratching contact of the overlay-visor with the helmet components when lifting the visor assembly. In another embodiment the spacing may be greater at the lateral side portions than in the central portion.
In a particular example the height of the spacer may be about 0.5 mm along a first portion of a visor with a seamless graduation to 1.0 mm at an opposed portion of the visor. In this manner a chamber is provided with a gradually increasing spacing from one portion to another. Preferably, the height variation is achieved by variation in the height of the integrally formed spacer, and the gasket has a constant thickness.
In general, the spacing between the overlay-visor and the shield-visor can be adjusted to optimise the anti-misting properties of the assembly, by adjustment of the height of the integrally formed spacer.
The gasket may be applied to the overlay-sheet by a number of techniques.
The spacer or gasket is preferably applied to the overlay-sheet as a fluid, e.g. by extrusion through a nozzle or by injection molding, as a melt, suspension, dispersion, solution, gel or liquid.
The fluid material preferably comprises compositions that are thixotropic, preferably including shear-thinning rheology modifiers. This may allow easy application for manufacture (e.g. during nozzle or injection molding) yet also maintain a desired transverse cross section until the gasket composition has set or cured.
For example, the gasket may be applied by coating, painting, brushing, spraying, extrusion via a nozzle, or any other appropriate method, 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.
A CNC machine controls a resin dispensing nozzle that extrudes a bead of resin under pressure onto the overlay-visor in the appropriate pattern. Once the resin has been applied to the overlay-visor, the bead is allowed to cure.
In such a process accurate computer numerical control has to be utilised in order to achieve excellent bead placement, bead thickness and bead cross-section control.
Various transverse cross sections of the gasket can be obtained by selection of extrusion port shapes on a nozzle, for example curved or polygonal. The rheology of the applied fluid material can be chosen to be thixotropic such that it maintains a shape resulting from an extrusion nozzle's orifice.
Alternatively, the gasket may be prefabricated as a solid or semi-solid, which is pre-shaped and then joined to the overlay-sheet by adhesion techniques, or by laser/ultrasonic welding.
Alternatively, the gasket may be applied by injection molding onto an overlay-sheet body.
The overlay-sheet is in one embodiment provided as a visor prefabricated by cutting or milling from a sheet of material. The overlay-visor may alternatively be formed by injection molding, or other known techniques.
A projection for the overlay-sheet is preferably integrally formed into the overlay-shield by mechanical deformation of the overlay-shield. This can be done, for example, by mechanical deformation, preferably thermally, with a mould. That is, a sheet-like overlay-shield can be provided with a protrusion in a simple manner via mechanical deformation.
The gasket may be applied to a distal surface of the projection by the techniques discussed herein.
In a preferred embodiment the shield-visor of the visor assembly is provided with a recess shaped to receive an overlay-visor. The dimensions of the recess preferably correspond closely to the peripheral dimensions of the overlay-visor. The depth of the recess is preferably such that when the overlay-visor is inserted it sits substantially flush with the un-recessed part of the shield-visor.
As discussed, the overlay-visor maintains a user's vision through the visor assembly. In relation to this the overlay-visor is preferably provided with an anti-misting surface, for example, in the form of a surface having hydrophilic properties. The surface may be applied as a coating of a hydrophilic material. The coating is preferably a silicone-based material which is applied by dip-coating. More preferably the overlay-visor is also provided with an anti-misting surface on both of its major surfaces.
The overlay-visor may also or alternatively be provided with a colouring agent in the form of a permanent colouring or a photo-chromic UV reactive dye. This acts to reduce the ingress of excess light during, for example, sunny conditions, or to filter particular wavelengths of light.
The overlay-visor may be provided with an anti-scratch coating, separately or in combination with an anti-misting surface, on either or both of its major surfaces. Preferably the overlay-visor is provided with an anti-misting surface on one side and an anti-scratch surface on the other side.
It will be clear to those skilled in the art that the seal member may be provided at alternative locations on the overlay-sheet so long as it encompasses an adequate viewing area for the visor user. For example, the overlay-sheet may be larger than the viewing area of the visor, but the seal member located on the periphery of the viewing area, and thus not on the periphery of the overlay-sheet.
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, optionally with a backing sheet releasably adhered to and protecting the tacky surface of the overlay-sheet, 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. Optionally the kit of parts may also comprise a safety helmet on which the visor assembly can be fitted.
The shield visor may be made of polycarbonate and the substrate of the overlay-sheet of cellulose acetate. Differences in both contraction and expansion can be overcome with the aid of an adequately rubbery elastic seal.
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.
According to another aspect of the invention there is provided a safety helmet assembly comprising a safety helmet, and a visor assembly as discussed above fitted, or suitable to be fitted to the safety helmet.
Specific embodiments of the invention will now be described by way of non-limiting example only. The features and advantages of the invention will be further appreciated upon reference to the following drawings, in which:
a and 4b show a visor assembly having a shield-visor with a recess;
Also illustrated in
As a result of the presence of this spacer 7, the overlay-visor 6 is spaced from the shield-visor 2 and a chamber is formed between the overlay-visor 6 and the shield-visor 2. This chamber acts as an insulator reducing condensation formation in the viewing area of the shield-visor 2. It will be clear to those skilled in the art that the spacer 7 may be provided at alternative locations on the overlay-visor 6 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 7 located on the periphery of the viewing area, and thus not on the periphery of the overlay-visor 6.
The spacer 7, in the form of an PSA elastomeric gasket seal, is adhered to the overlay-visor 6 and is held in non-permanent adhesive relation to the shield-visor 2. The overlay-visor 6 is removable from the shield-visor 2 so that it can be replaced if damaged or removed or replaced depending upon weather conditions.
Spacer 7 provides a seal between the overlay-visor 6 and the shield-visor 2, as a result of which ingress of moisture, and consequently misting up of the shield-visor 2, can be avoided.
In
In
In
In
In
In
The overlay-visors can be manufactured by a process in which the spacer/seal? is extruded from a nozzle or caulked onto the overlay-visor 6.
The overlay-visors can be manufactured by a process in which the spacer/seal? is injection molded directly onto the overlay-visor 6. In such a process use is made of a mold 30. Partial cross-sections of a mold are shown in
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
In an alternative embodiment (not shown) a seal 7 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 embodiment 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.
The overlay-visor 6 is a single-piece element including the part that is the viewing area and its spacer 7. That is, the overlay visor 6 is integrally formed as single-piece element.
In
In
In
In
In the cross sections of
In
Many modifications in addition to those described above may be made to the structures and techniques described herein without departing from the spirit and 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.
Equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.
The following clauses describe various aspects of the invention.
Clause 1. An overlay-visor adapted to be releasably attached to a shield-visor, the overlay-visor comprising a viewing area, a spacer extending along at least a portion of a periphery of the viewing area, wherein a distal surface of the spacer is tackified.
Clause 2. The overlay-visor according to clause 1 wherein the spacer comprises a tackifier.
Clause 3. The overlay-visor according to clause 1 or 2 wherein the spacer comprises a gasket comprising a tackified material.
Clause 4. The overlay-visor according to any preceding clause, wherein the spacer has an adhesive external surface facing away from the overlay-visor, wherein the adhesive surface is a non-permanent adhesive, preferably a pressure sensitive adhesive.
Clause 5. The overlay-visor according to any preceding clause wherein the gasket is elastically deformable.
Clause 6. The overlay-visor according to any preceding clause wherein the spacer has a convex, concave, polygonal, rectangular, square, U-shaped, Z-shaped, W-shaped or multi-channeled transverse cross section.
Clause 7. The overlay-visor according to any preceding clause wherein the spacer, preferably the gasket, comprises a pressure-sensitive adhesive
Clause 8. The overlay-visor according to any preceding clause wherein the spacer, preferably the gasket, comprises any of natural rubber, acrylics, nitriles, styrene-isoprene block copolymers, silicones, vinyl ethers, butyl rubber or combinations thereof.
Clause 9. The overlay-visor according to any preceding clause wherein the spacer, preferably the gasket, comprises one or more silicone polymers and one or more MQ silicate resins.
Clause 10. A visor assembly comprising
Clause 11. The assembly according to clause 10, wherein the overlay-visor is adhered to the shield-visor and the adherence is peelably releasable.
Clause 12. A kit of parts comprising;
Clause 13. A helmet comprising;
Clause 14. 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:
Clause 15. The method of clause 14, wherein the overlay-visor is in accordance with any of clauses 1 to 9.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20151239.9 | Jan 2020 | EP | regional |
