A cover for attachment to an elongate member and a corresponding method, kit and framework

Abstract

A cover 1 for attachment to an elongate member 2 is provided. The cover having an inner side 9 facing the elongate member in use, and an outer side 10 opposite to the inner side. The cover comprising: an optical element 3 configured to redirect light to at least partially obscure the elongate member from at least one viewpoint; and at least one attachment element 4 configured to attach the optical element to the elongate member.

Description

[0001] PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0002] - 1 -

[0003] A COVER FOR ATTACHMENT TO AN ELONGATE MEMBER AND A CORRESPONDING METHOD, KIT AND FRAMEWORK

[0004] FIELD

[0005] 5 This invention relates to an apparatus for hiding visual obstruction and, more particularly, to a cover for attachment to an elongate member to at least partially obscure the elongate member from view, a method of obscuring an elongate member, a kit for covering a framework of elongate members, and a framework comprising one or more elongate members.

[0006] BACKGROUND

[0007] Security bars and grilles are used to secure windows and doors. They are commonly formed from bars or struts extending across the opening of the window or door. While providing security by preventing unwanted access, these structures may be unsightly or block views for a viewer looking through the window or door. Decorative covers intended to hide such structures may

[0008] 15 themselves further obscure the viewer’s view through the door or window.

[0009] Similarly, other frameworks of bars, struts or other elongate members such as parts of pylons, cranes or scaffolds may be unattractive in appearance or block an observer’s view.

[0010] 20 The present invention seeks to address these issues by providing a device that obscures their appearance.

[0011] SUMMARY

[0012] A cover for attachment to an elongate member is provided. The cover comprising: an optical

[0013] 25 element configured to redirect light to at least partially obscure the elongate member from at least one viewpoint; and at least one attachment element configured to attach the optical element to the elongate member.

[0014] The cover may have an inner side facing the elongate member in use, and an outer side opposite to the inner side.

[0015] This provides a cover which can be used to obscure the appearance of an elongate member.

[0016] The cover may further comprise one or more of the following features.

[0017] 35 PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0018] - 2 -

[0019] The optical element may be a lens.

[0020] This is an effective way to obscure the elongate member. A number of adjacent lenses (such as adjacent convex and / or concave lenses) can collectively be referred to as a lens in this context.

[0021] 5

[0022] The optical element may be a lenticular lens. Such a lens can be particularly effective in obscuring an elongate member.

[0023] The optical element may be elongate in a first direction. This helps to obscure the member, which is itself elongate.

[0024] The optical element may have a curved or arched cross-sectional profile in a plane arranged generally perpendicular to the first direction. This shape can help redirect light to obscure the elongate member.

[0025] 15

[0026] The optical element may extend through at least a 60 degree arc, preferably a 100 degree arc, more preferably a 120 degree arc. The wider the optical element (i.e. the greater the arc angle), the more the elongate member is covered at oblique angles.

[0027] 20 The optical element may have a cross-section perpendicular to the first direction comprising a plurality of alternating peaks and troughs, the alternating peaks and troughs lying in at least one surface of the optical element. In some examples, the alternating peaks and troughs form a plurality of repeating curves. This is an effective element shape for redirecting light.

[0028] 25 The optical element may have undulations that extend perpendicular to the first direction. Undulations are smooth curves with no sharp corners or points, which may be beneficial when manufacturing the cover.

[0029] The optical element may be a lenticular lens and may comprise a plurality of elongate lenticules, the lenticules being aligned parallel to the first direction. A lenticular lens arranged in this manner can effectively redirect light to obscure the elongate member.

[0030] At least some of the plurality of elongate lenticules may be arranged on the inner side of the cover. This allows the light passing from the inner side of the cover to the outer side of the cover

[0031] 35 to be redirected such that the elongate member is more effectively obscured. PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0032] - 3 -

[0033] At least some of the plurality of elongate lenticules may be arranged on the outer side of the cover. Providing lenticules on the outer side of the cover can allow the image of the elongate member to be more effectively obscured as the image will be less visible to an observer on the

[0034] 5 outer side of the cover, for example when there are elongate lenticules on the inner side and the outer side of the cover.

[0035] The optical element may comprise at least one undulating surface of the cover defining the peaks and the troughs. An undulating surface is smoothly curved with no sharp corners or points, which may be beneficial when manufacturing the cover.

[0036] The at least one undulating surface may define a series of alternating convex and concave lenses. Such a series of lenses obscures the elongate member due to the interaction of light with the collective series of alternating convex and concave lenses.

[0037] 15

[0038] The at least one undulating surface of the cover may be substantially sinusoidal (this includes strictly sinusoidal). A sinusoidal surface may have an improved obscuring effect on the image of the elongate member, and may be manufactured with improved efficiency, precision, and ease.

[0039] 20 The at least one undulating surface may comprise an inner undulating surface formed on the inner side of the cover.

[0040] The at least one undulating surface may comprise an outer undulating surface formed on the outer side of the cover.

[0041] 25

[0042] The formation of the undulating surface on one or both sides of the cover can have varying advantageous effects. For example, undulating surfaces being on both the inner and outer sides may more effectively obscure an elongate member due to the cooperation of the refractive effects of the undulating surfaces of both sides. Alternatively, a single-sided cover having either one of an inner undulating surface or an outer undulating surface may be preferred. For example, it may be a simpler cover to manufacture.

[0043] In some examples, the inner undulating surface and the outer undulating surface may be in phase such that the peaks of the inner undulating surface are aligned with the troughs of the

[0044] 35 outer undulating surface. In some examples, the inner undulating surface and the outer PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0045] - 4 - undulating surface may be out of phase such that the peaks of the inner undulating surface are aligned with the peaks of the outer undulating surface. When the inner undulating surface and the outer undulating surface are in phase

[0046] 5 The cover may extend between a first cover edge and a second cover edge and a distance between adjacent peaks may decrease from a central region of the cover towards the first cover edge and the second cover edge. In use, the first and second cover edges may be closer to the elongate member than the central region of the cover, and so having a decreasing distance between adjacent peaks towards the cover edges may improve the obscuring of the bar as a decreasing distance, and thus an increasing frequency, may correspond to a shorter focal length.

[0047] The cover may extend between a first cover edge and a second cover edge and each peak may have a peak amplitude which is a height of the peak relative to an adjacent trough on that

[0048] 15 surface of the optical element, wherein the peak amplitude decreases from a central region of the cover towards the first cover edge and the second cover edge. In such a cover, the obscuring effect has the visual effect of ‘fading away’ towards the cover edges. As such, to an observer, the transition from viewing an obscured elongate member to an unobscured elongate member is smoother.

[0049] 20

[0050] The cover may have a minimum thickness measured from the inner side to the outer side, and a focal length of the optical element may be less than the minimum thickness of the cover. Such a thickness allows the image of the elongate member formed by the optical element to be better obscured because the image focuses within the thickness of the cover, creating a visual effect

[0051] 25 of the image of the elongate member being ‘trapped’ and therefore more effectively obscured.

[0052] The optical element may be elongate in a first direction and: the at least one attachment element extends along a length of the optical element in the first direction; or the at least one attachment elements comprise a first attachment element and a second attachment element, the first attachment element being spaced from the second attachment element in the first direction. This can result in a secure attachment of the cover / optical element to the elongate member.

[0053] The or each attachment element may be configured to position the optical element at a

[0054] 35 separation distance from a surface of the elongate member; wherein optionally the separation PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0055] - 5 - distance is uniform along the length of the cover in the first direction. Spacing the optical element from the surface of the elongate member means that more light is diverted to either side of the elongate member thereby reducing the visibility of the elongate member through the optical element.

[0056] 5

[0057] The separation distance may be between 20 mm and 4 mm. Within this range, the separation distance is such that the light is diverted to either side of the elongate member for effective obscuring of the member while also ensuring that the image formed of the elongate member by the light passing through the optical element is focused in such a way that the elongate member is obscured.

[0058] The frequency of the peaks may be between 15 per inch and 300 per inch, preferably between 20 per inch and 150 per inch. Within this range, the frequency of the peaks is such that the dimensions of each peak and the spacings therebetween allow for a focal length of the optical

[0059] 15 element which obscures the member most effectively.

[0060] The or each attachment element may comprise a clip configured to snap fit onto the elongate member. This allows for easy attachment of the cover to the elongate member.

[0061] 20 The optical element may be elongate in a first direction wherein the or each attachment element comprises a concave seat arranged to extend around an attachment axis corresponding to a longitudinal axis of the elongate member, the attachment axis being parallel to the first direction. This also allows for easy attachment of the cover to the elongate member.

[0062] 25 The optical element may comprise a primary optical element, and a plurality of secondary optical elements at an angle to the primary optical element, the primary optical element arranged between the secondary optical elements. The primary optical element provides the front-on obscuring of the elongate member and so is optimised for this, with the secondary optical elements providing supplementary obscuring for less-direct angles.

[0063] The attachment element may comprise an interface member configured to attach to the elongate member, and a connector configured to attach the optical element to the interface member. This allows for the cover to be attached to elongate members where other methods such as snap fitting are not appropriate. PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0064] - 6 -

[0065] The elongate member may be one of: a structural strut or bar; or a security bar for a door or window. These are typical elongate members which can be unattractive, and hence a user may want to obscure.

[0066] 5 A method of obscuring an elongate member is provided. The method comprises: providing a cover as discussed herein; and attaching the cover to the elongate member using the at least one attachment member.

[0067] This method results in the cover obscuring the appearance of the elongate member.

[0068] The method may further comprise one or more of the following features.

[0069] Providing the cover may comprise determining a width of the elongate member measured perpendicular to its elongate direction and selecting a cover having a width which is no more

[0070] 15 than 2 times the width of the elongate member, preferably no more than 1.7 times the width of the elongate member. If the cover is too wide with respect to the elongate member, the view beyond the cover / elongate member would be obscured and hence the effect of the cover would be less subtle.

[0071] 20 Providing the cover may comprise determining a separation distance at which the optical element is from a surface of the elongate member, a ratio of the separation distance to the width of the elongate member being between 8:13 and 18:13. This provides a good balance between the competing effects of the spacing. The farther away the optical element is from the elongate member, the more light is diverted to either side of the elongate member thereby reducing the

[0072] 25 visibility of the elongate member through the optical element. However, the closer the optical element is to the elongate member, the wider the angle of the optical element is to the elongate member.

[0073] A kit for covering a framework of elongate members is provided. The kit comprises a plurality of covers as discussed herein.

[0074] This kit allows for the elongate members of the framework to be obscured.

[0075] A framework is provided. The framework comprises: one or more elongate members; and at

[0076] 35 least one cover as discussed herein; wherein each cover of the at least one covers extends PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0077] - 7 - along an elongate member of the one or more members and is secured thereto by the one or more attachment elements of the cover.

[0078] The elongate members of the framework are obscured by the covers being attached thereto.

[0079] 5

[0080] The framework may further comprise one or more of the following features.

[0081] Each cover may be elongate in a direction which is parallel to an elongate direction of the elongate member to which it is attached. This aligns the cover and the elongate member, effectively obscuring it.

[0082] The one or more elongate members may form: a security grille for a door or window, wherein each of the elongate members is a bar or strut of the security grille; or a crane framework, scaffold or pylon wherein each of the elongate members is a bar or strut. These are typical elongate members which can be unattractive, and hence a user may want to obscure.

[0083] The cover may be arranged to at least partially surround the elongate member. This helps to obscure the elongate member.

[0084] The cover may have a width in a direction perpendicular to the first direction which is no more than 2 times the width of the elongate member in the same direction, preferably no more than 1 .7 times the width of the elongate member. If the cover is too wide with respect to the elongate member, the view beyond the cover / elongate member would be obscured and hence the effect of the cover would be less subtle.

[0085] The one or more attachment elements of the or each cover may be sized to snap-fit onto the elongate member to which it is attached. This allows for easy attachment of the cover to the elongate member.

[0086] 30 A method of manufacturing a cover for attachment to an elongate member is provided. The method comprises providing a die for extrusion and passing heated material through an aperture of the die to form the cover for attachment to the elongate member wherein the aperture of the die is shaped with undulations. PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0087] - 8 -

[0088] Manufacturing the cover by extrusion according to the above method allows the cover to be formed with the specific shaping of the optical element in a single step. This method can also be precise and efficient in terms of both cost and materials.

[0089] 5 The aperture of the die may comprise a curved or arched portion for forming the optical element of the cover. This allows the optical element to be formed in a single step of profile extrusion.

[0090] The aperture of the die may comprise an attachment aperture portion for forming the attachment elements. This allows the cover to be formed as a single piece including the optical element and the attachment elements.

[0091] BRIEF DESCRIPTION OF THE DRAWINGS

[0092] Embodiments of the disclosure will now be described, by way of example only, with reference to the following non-limiting schematic figures in which:

[0093] Figure 1 is a perspective view of a first cover according to the invention attached to an elongate member;

[0094] Figure 2 is an end view of the cover of Figure 1 in which the optical element is a lenticular lens;

[0095] Figure 2A is a close-up view of the optical element of Figure 2;

[0096] Figure 3 is an end view of the cover of Figure 1 in which the optical element comprises undulating substantially sinusoidal surfaces;

[0097] Figure 3A is a close-up view of the optical element of Figure 3;

[0098] Figure 4 is a side view of the cover of Figure 1 ;

[0099] Figure 5 is an end view of the cover of Figure 1 attached to an elongate member;

[0100] Figure 6 is a side view of the cover of Figure 1 attached to an elongate member;

[0101] Figure 7 is a perspective view of a framework according to the invention;

[0102] Figure 8 is a perspective view of a second cover according to the invention attached to an elongate member;

[0103] 30 Figure 9 is an end view of the cover of Figure 8 attached to an elongate member; and Figure 10 is a perspective view of a third cover according to the invention spaced from an elongate member. PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0104] - 9 -

[0105] DETAILED DESCRIPTION

[0106] Figures 1 to 6 show examples of covers 1 according to a first embodiment. These covers 1 can be referred to as a first cover 1. The cover 1 being for attachment to an elongate member 2 as best shown in Figures 1 , 5 and 6. The elongate member 2 may be a bar, such as a security

[0107] 5 grille. The member 2 may be defined as elongate in that it is longer in one dimension, along a longitudinal axis 6, than the others. The cover 1 is elongate in a first direction. In use, particularly when the cover 1 is attached to the elongate member 2, the first direction may be parallel to a longitudinal axis 6 of the elongate member 2.

[0108] The cover 1 comprises one or more attachment elements 4, as discussed in more detail below. The cover 1 comprises an inner side 9 and an outer side 10 as shown in Figures 2 and 3. The inner side 9 faces (i.e. is closer to) the elongate member 2 in use. The outer side 10 is opposite to this inner side (i.e. is further away from the elongate member 2 in use).

[0109] 15 The cover 1 extends between a first cover edge 13 and a second cover edge 14. A central portion of the cover 1 may be identified between the first cover edge 13 and the second cover edge 14. It is appreciated that in this context “first” and “second” simply identify the cover edges 13, 14 and either cover edge 13, 14 can be identified as the “first” or the “second” cover edge

[0110] 13, 14. Each cover edge 13, 14 extends substantially in the first direction as noted above. The

[0111] 20 cover 1 extends substantially transverse to the first cover edge 13 and the second cover edge

[0112] 14. The first and second cover edge 13, 14 may be edges of the attachment elements 4 of the cover 1 .

[0113] The cover 1 comprises an optical element 3. The optical element 3 is configured to redirect light

[0114] 25 to at least partially obscure the elongate member 2 from at least one viewpoint.

[0115] The optical element 3 may be a light-diffusing material such that the diffusion of light passing from the inner side 9 of the optical element 3 to the outer side 10 (and vice-versa) obscures the elongate member 2 from the at least one viewpoint.

[0116] In certain examples, such as shown in Figures 2, 2A, 3, and 3A, the optical element 3 comprises at least one surface comprising a plurality of repeating elongate curves having alternating peaks 11 and troughs 12. A peak 11 being a local protrusion of the optical element 3, and a trough 12 being a recessed section in between adjacent peaks 11. Different types of

[0117] 35 lenses will be discussed in more detail below, but in brief Figures 2 and 2A show an example in PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0118] - 10 - which the optical element 3 is a lenticular lens and Figures 3 and 3A show an example in which the optical element 3 is a sinusoidal lens.

[0119] The curves may be elongate parallel to or in the first direction. The peak 11 and troughs 12 of

[0120] 5 the elongate curves are best seen from the end views of the covers 1 as shown in Figures 2 to 3B.

[0121] Figures 2 and 2A show an example of the cover 1 where the optical element comprises one or more lenticular lenses. In particular, in which the optical element 3 is a lenticular lens array or sheet, or a lenticular lens. In embodiments where the optical element 3 is a lenticular lens, the peaks 11 may be defined as the vertex (i.e. most protruding point) of each lenticule 7 of the lenticular lens. The troughs 12 may be defined as the points where adjacent lenticules 7 meet. Therefore, the troughs 12 may be generally V-shaped, or a radius may be applied at this meeting of adjacent lenticules 7.

[0122] 15

[0123] Figures 2 and 2A show an example where lenticules 7 are only provided on the inner side 9 of the cover 1. In further examples, the lenticules 7 may be provided only on the outer side 10 of the cover 1 , or on both the inner side 9 and the outer side 10 of the cover 1 . More information relating to the lenticules 7 is provided below.

[0124] 20

[0125] In some examples, as shown in Figures 3 and 3A, the optical element 3 comprises at least one undulating surface 15 defining the peaks 11 and the troughs 12. Unless otherwise expressly stated to the contrary, any disclosure in relation to the cover 1 of Figures 2 and 2A is equally applicable to the cover of Figures 3 and 3A, and vice-versa. An undulating surface 15 may be

[0126] 25 defined as a surface with a rising and falling outline, as shown in Figures 3 and 3A.

[0127] Figures 3 and 3A show an example where the undulating surface 15 comprises both an inner undulating surface on the inner side 9 of the cover 1 , and an outer undulating surface on the outer side 10 of the cover 1. However, in other examples there may be only an inner undulating surface, or only an outer undulating surface.

[0128] The peaks 11 may be defined as the vertex (i.e. most protruding point) of the undulating surface 15, and the troughs 12 may be defined as the innermost point of the undulating surface 15. More information relating to the undulating surface 15 is provided below.

[0129] 35 PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0130] - 11 -

[0131] The first cover 1 of Figures 1 to 6 has an attachment element 4 either side of the optical element 3. In the first cover 1 , each attachment element 4 extends along a length of the cover 1 in the first direction.

[0132] 5 The attachment elements 4 comprise a pair of resilient arms which define an opening 6a for receiving an elongate member 2. The resilient arms are biased to a position where a spacing between the arms is smaller than a reference dimension (such as a diameter) of the elongate member.

[0133] Each arm may be formed with an apex arranged to receive the elongate member 2, this can allow the cover 1 to be used with elongate members 2 of different reference dimension (such as width or diameter). The arms may be pivoted with respect to the optical element 3 such that a distance between the apexes of the arms can be varied.

[0134] 15 The attachment element 4 of this example is formed substantially integrally / unitary with the optical element 3 of the cover 1. For example, the cover 1 may be formed of a single sheet of material which is shaped to form the optical element 3 and the attachment element(s) 4.

[0135] The cover 1 may be formed as a single piece through extrusion, 3D printing, or any other

[0136] 20 suitable manufacturing method.

[0137] Of course, other arrangements for the attachment element 4 may be used, as discussed herein. For example, this could incorporate one or more of: an adhesive element, a spacer with adhesive, a hook-and-loop strap (e.g. Velcro), circlip, bracket, or fastener.

[0138] 25

[0139] As in the illustrated example, the optical element 3 may be elongate in the first direction. The optical element 3 may have a curved or arched cross-sectional profile in a plane arranged generally perpendicular to the first direction. However, in further examples the optical element 3 may be substantially flat.

[0140] In use, the cover 1 of the present invention may be arranged to at least partially obscure and / or surround the elongate member 2. As best shown in Figures 2 and 3, the illustrated optical element 3 extends through a 180 degree arc about the attachment axis 5. As explained in more detail below, the optical element 3 is formed of a primary optical element 3a, and one or more

[0141] 35 secondary optical elements 3b. It is the combination of each of these that defines the extent of PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0142] - 12 - the arc. As discussed herein, other arc angles are also possible. For example, the optical element 3 or cover 1 may extend through at least a 60 degree arc, preferably a 100 degree arc, more preferably a 120 degree arc. The arc is in a plane arranged generally perpendicular to the first direction.

[0143] 5

[0144] An attachment axis 5 can be defined for the attachment elements 4 as an axis defined through a centre point of an opening 6a of one or more of the attachment elements 4, the opening being configured to receive the elongate member 2 in use. The attachment axis 5 may be generally parallel to the first direction. However, other attachment elements 4 may be used where this is not the case. The arc of the optical element 3 or cover 1 may be about this attachment axis 5.

[0145] Without being bound by theory, the wider the optical element 3 (i.e. the greater the arc angle), the more the elongate member 2 is covered at oblique angles (i.e. not perpendicular to a front of the optical element 3. This improves the effect of hiding the elongate member 2 from all locations in a room / environment / space. However, the narrower the optical element 3 (up to being the same width as the reference dimension (such as the diameter) of the elongate member 2) the less of the view beyond the cover 1 and / or elongate member 2 is obscured, so the more low-profile the resulting effect is when viewed from the front.

[0146] As shown in Figures 2 and 3, the optical element 3 may be formed of a primary optical element 3a, and one or more secondary optical elements 3b. In the examples of Figures 2 and 3, there are two secondary optical elements 3b, either side of the primary optical element 3a in a plane arranged generally perpendicular to the first direction.

[0147] Each secondary optical element 3b may be angled with respect to the primary optical element 3a. In other words, a separation distance from a surface of the elongate member 2 may be different for the primary optical element 3a and each secondary optical element 3b. Specifically, for example, each secondary optical element 3b may have a smaller separation distance than the primary optical element 3a.

[0148] 30

[0149] The primary optical element 3a performs the primary redirection of light to at least partially obscuring the elongate member 2. The primary optical element 3a may, therefore, be provided substantially centrally on the cover 1 . The cover 1 may be symmetric in a plane defined in the first direction. In use, the primary optical element 3a may be positioned substantially “front on” to PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0150] - 13 - the elongate member 2. That is, in the primary direction that the elongate member 2 will be viewed from in use.

[0151] The primary optical element 3a may extend through an arc of at least 40 degrees, preferably at

[0152] 5 least 50 degrees, more preferably at least 60 degrees. Each secondary optical element 3b may extend through an arc of at least 20 degrees, preferably at least 30 degrees. Collectively, the sum of the arcs of the primary optical element 3a and each secondary optical element 3b form the full arc of the optical element 3.

[0153] The optical element 3 can also be defined in relation to the edge of the elongate member 2. Particularly, be defining a plane which touches, but does not intersect with, the elongate member 2 and which passes through the edge of the optical element 3. This can be defined as the “edge plane”. In examples with a primary optical element 3a and secondary optical elements 3a, a “primary edge plane” and a “secondary edge plane” can be defined. There will be two of each edge plane, for either side of the elongate member 2 and optical element 3. In other words, there may be a plane defined which passes from an outermost edge of the elongate member 2 to the corresponding outermost edge of the optical element 3.

[0154] Between the two edge planes, an edge angle can be defined. The edge angle may be at least 20 degrees.

[0155] For examples with a primary optical element 3a and secondary optical elements 3b, there is a primary edge angle and a secondary edge angle. The primary edge angle may be at least 20 degrees. The secondary edge angle may be at least 40 degrees, preferably at least 50 degrees.

[0156] Where the optical element 3 is a lenticular lens, the lenticular lens sheet forming the optical element 3 of the first embodiment comprises a plurality of elongate lenticules 7, each lenticule 7 being a curved lens, for example a convex lens. The lenticules 7 are aligned parallel to the first direction, such that the lenticules 7 are parallel to the longitudinal axis 6 of the elongate member

[0157] 30 2. The lenticules 7 may be arranged adjacent to one another, such that they have intersecting radii of curvatures.

[0158] In use, at least some of, or all of, the lenticules 7 may face the elongate member 2. That is, the lenticules 7 may be on the same side of the cover 1 as the attachment element(s) 4. In other PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0159] - 14 - words, the lenticules 7 may be on the inner side 9 of an arc of the cover 1. At least some of the lenticules 7 may be on the outer side 10 of the cover 1.

[0160] In some examples, the optical element 3 comprises at least one undulating (or corrugated)

[0161] 5 surface 15 of the cover 1 defining the peaks 11 and the troughs 12. This undulating surface 15 may define a series of alternating convex and concave lenses defined by the peaks 11 and the troughs 12. The convex and concave lenses are defined based on the curvature of the lenses relative to the surface of a cover 1 without an undulating surface 15. The convex lenses may be defined by the peaks 11 of the undulating surface 15, while the concave lenses may be defined by the troughs 12 of the at least one undulating surface 15. The convex and concave lenses may be elongate parallel to the first direction.

[0162] The troughs 12 and / or peaks 11 of the at least one undulating surface 15 are curved. This curvature can improve the ease of manufacture by extrusion due to the absence of sharp

[0163] 15 corners in the design for extrusion.

[0164] As shown in Figures 3 and 3A, the at least one undulating surface 15 may be substantially sinusoidal and follows the curvature of a sinusoidal curve. Of course, the cover 1 may be curved and so the centre-line of the sinusoidal curve may be correspondingly curved to follow the

[0165] 20 shape of the cover 1.

[0166] The sinusoidal curve defines a curvature, focal length, amplitude, and frequency of the convex and concave lenses of the optical element 3.

[0167] 25 Alternatively, the at least one undulating surface 15 may not follow a sinusoidal curve. The at least one undulating surface 15 may be a modified lenticular lens sheet. The at least one undulating surface 15 may comprise curved lenses such as convex lenses or lenticules forming the peaks 11 of the at least one undulating surface 15 and they may be separated by curved, concave portions forming troughs 12 between the lenticules 7.

[0168] In certain examples, a radius of curvature of the convex lenses may be greater than a radius of curvature for the concave lenses.

[0169] The cover 1 may comprise an inner undulating surface 16, on the inner side 9 of the cover 1 , an

[0170] 35 outer undulating surface 17 on the outer side 10 of the cover, or both. PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0171] - 15 -

[0172] In examples with both an inner undulating surface 16, and an outer undulating surface 17, the inner undulating surface 16 and the outer undulating surface 17 may be in phase with one another. Being in phase is defined by taking the curves of each undulating surface 16, 17 and

[0173] 5 overlaying these. In phase curves substantially overlap one another. In this sense, when the undulating surfaces 16, 17 are in phase, the peaks 11 of the inner undulating surface 16 are aligned with the troughs 12 of the outer undulating surface 17, with the peaks 11 and troughs 12 of the inner undulating surface 16 and the outer undulating surface 17 being defined relative to the surface of a cover 1 without an undulating surface 15.

[0174] Figures 3 and 3A show an example in which the inner undulating surface 16 and the outer undulating surface 17 are out of phase, such that the peaks 11 of the inner undulating surface 16 are aligned with the peaks 11 of the outer undulating surface 17. Again, if the curves of each undulating surface 16, 17 were overlaid this would mean that the curves do not overlap one

[0175] 15 another. For example, in the case of sinusoidal undulating surfaces 16, 17 these may be phase shifted by TT radians or 180°.

[0176] The inner undulating surface 16 and the outer undulating surface 17 may cover different parts of the inner and outer sides 9, 10 of the cover 1. For example, Figure 3 shows the outer undulating

[0177] 20 surface 17 extending on the outer side 10 onto the attachment element 4, while the inner undulating surface 16 does not.

[0178] The lenses of the optical element 3 have a frequency. “Lenses” refers to the convex and concave lenses where the optical element 3 comprises an undulating surface 15, and the

[0179] 25 lenticules where the optical element 3 is a lenticular lens. This may be the frequency of the lenses, of the lenticules, or of the sinusoidal curve defining the undulating surface 15. The frequency can be determined according to the distance 18 between adjacent peaks 11 on the surface of the optical element 3. The frequency may be measured according to the number of lenses or lenticules per inch, or LPL For a sinusoidal curve, this may be the number of convex peaks per inch.

[0180] The frequency of the lenses of the optical element may vary along the optical element. For example the frequency may decrease towards the cover edges 13, 14. In other words, the distance 18 between adjacent peaks may increase towards the cover edges. The distance 18

[0181] 35 between adjacent peaks may be greater proximal to each cover edge 13, 14, and the frequency PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0182] - 16 - may be greater, and the distance between adjacent peaks 11 may be less, distal from each cover edge 13, 14 - towards a central region of the cover 1 . Without wanting to be bound by theory, a higher frequency will generally have a shorter focal length, meaning it can be closer to the elongate member 2 (as in at the side sections).

[0183] 5

[0184] The lenses of the optical element have a peak amplitude 19. The peak amplitude 19 is the height of each peak 11 relative to the adjacent trough 12. As there are two adjacent troughs 12 for each peak 11 , the peak amplitude 19 may be taken as an average of the heights relative to each of the troughs 12. The height is measured perpendicular to the peaks 11.

[0185] Where the optical element 3 is a lenticular lens, the peak amplitude 19 is equivalent to the sagitta or sag of each lenticule. Where the optical element 3 comprises an undulating sinusoidal surface 15, the peak amplitude 19 is twice the mathematical amplitude of the sinusoidal curve which the undulating surface 15 follows.

[0186] 15

[0187] The peak amplitudes 19 of the lenses of the optical element 3 may vary along the optical element. The peak amplitude 19 may decrease towards each cover edge 13, 14. The peak amplitude 19 may be constant distal from the cover edges 13, 14 (i.e. in a central region of the cover 1). For example, the peak amplitude 19 may decrease starting from the twentieth lens, the

[0188] 20 sixteenth lens, the tenth lens, or the eighth lens, from the cover edge.

[0189] Due to the decreasing frequency and amplitude of the lenses of the optical element 3 towards the cover edges 13, 14, which, in the first cover 1 , are positioned toward the back of the elongate member 2, the impression of the obscuring of the elongate member 2 when viewed

[0190] 25 from different viewpoints is improved.

[0191] The frequency of the lenses of the optical element 3 may be between 15 and 300 LPI, or between 20 and 150 LPI. For example, the distance 18 between the adjacent peaks of the lenses of the optical element may be between 0.01” and 0.05”, corresponding to between 20 and 100 LPI. The frequency of the lenses of the optical element may be, for example, 35 LPI.

[0192] The peak amplitude 19 of the lenses, which, for a lenticular lens, is the sag of the lenticules 7, may be at least 0.0005”. Separately to, or in combination with, this lower limit the sag may be up to 0.25” (for example for a utility pole) or up to 0.05” (for example for a security bar)

[0193] 35 PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0194] - 17 -

[0195] The cover 1 has a thickness 20 as shown in Figures 2 and 3. This thickness 20 is measured as the distance from the inner side 9 to the outer side 10. The thickness 20 is measured in the region of the optical element 3. The thickness 20 may be the maximum thickness in the region of the optical element 3. For example, as shown in Figure 3, with out of phase undulating

[0196] 5 surfaces 15, 16, the thickness 20 is measured from the peak 11 on the inner side 9 to the peak

[0197] 11 on the outer side 10. A minimum thickness 20a may also be measured from the trough 12 on the inner side 9 to the trough 12 on the outer side 10. In certain cases an average thickness can be taken of the minimum thickness and the (maximum) thickness 20.

[0198] The optical element 3 has a focal length less than the minimum thickness 20a of the cover 1. The focal length of the optical element 3 may be the focal length of the lenses or lenticules 7 forming the optical element 3. Such a configuration allows improved obscuring of the elongate member 2.

[0199] As best shown in Figure 5, the attachment element(s) 4 may be configured to position the optical element 3 at a separation distance 8 from a surface of the elongate member 2. The separation distance 8 may be uniform along the length of the cover 1.

[0200] The separation distance may be defined with respect to the size of the elongate member 2 that the cover 1 is to be attached on. Specifically, for example, this could be based on a reference dimension of the elongate member 2, the reference dimension being a dimension of the elongate member 2 perpendicular to the longitudinal axis 6 (such as a width). The reference dimension could be a diameter or width of the elongate member 2. The ratio between the reference dimension and the separation distance may be between 8:13 and 18:13.

[0201] Additionally, or alternatively, the separation distance may be between 50% to 100% of the reference dimension (such as width).

[0202] In practice, the separation distance may be between 8 mm to 18 mm, for example where the

[0203] 30 elongate member 2 is up to 0.5” wide (such as a security bar). A separation distance of between

[0204] 12 mm to 25 mm may be used for a 1” wide elongate member 2 or for a 3” wide pylon. A separation distance of between 125 mm and 250 mm may be used for a 10” wide elongate member 2 (such as a utility pole). PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0205] - 18 -

[0206] Without being bound by theory, the farther away the optical element 3 is from the elongate member 2, the more light is diverted to either side of the elongate member 2 thereby reducing the visibility of the elongate member 2 through the optical element 3. However, the closer the optical element 3 is to the elongate member 2, the wider the angle of the optical element 3 is to

[0207] 5 the elongate member 2 (defined below as the edge angle). There is therefore a balance between a large separation distance and a short separation distance.

[0208] Advantageously, the separation distance 8 can be related to the frequency of the lenses of the optical element 3. An appropriate separation from the elongate member 2 impacts the effectiveness of the obscuring of the elongate member 2. For a lens frequency between 20 LPI and 150 LPI, the separation distance 8 may be between 20 mm and 4 mm. For example, for an optical element 3 having a frequency of 35 LPI, the separation distance 8 may be in the region of 8 mm. For example, for an optical element 3 having a frequency of 80 LPI, the separation distance may be in the region of 4 mm.

[0209] 15

[0210] The frequency may in turn be related to the dimensions of the elongate member 2 to which the cover is attached. For example, a cover for obscuring an elongate member 2 having a larger diameter may have a smaller frequency of the lenses or peaks of the optical element, and a greater separation distance 8. In other words, the frequency may be inversely related to the

[0211] 20 diameter of the elongate member 2.

[0212] Figure 7 shows a plurality of covers 1 according to the first embodiment attached to a corresponding plurality of elongate members 2, as discussed in more detail below. This forms a framework.

[0213] 25

[0214] Figures 8 and 9 show a second embodiment of a cover 1 , which can be referred to as a second cover 1 . Unless otherwise expressly stated to the contrary, all features discussed in relation to the first cover 1 are equally applicable to the second cover 1 , and vice versa. The second cover 1 may include the optical element 3 of either of Figures 2 and 2A, or 3 and 3A.

[0215] The key difference for this second embodiment of the cover 1 is the use of alternative attachment elements 4. Reference will be made to a single attachment element 4, but in each case there may be multiple attachment elements 4 on a single cover 1 as discussed herein. For example, Figures 8 and 9 show two attachment elements 4.

[0216] 35 PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0217] - 19 -

[0218] The embodiment shown in Figures 8 and 9 is a two-part attachment element 4, comprising an elongate member interface member 4d and one or more connector(s) 4e. The interface member 4d is attachable to the elongate member 2, thus providing an interface between the elongate member 2 and the optical element 3. The connector(s) 4e are for attaching the optical element 3

[0219] 5 to the interface member 4d, and hence the elongate member 2.

[0220] The interface member 4d may be attached to the elongate member 2 in any suitable method. This could include, for example a strap 4f (such as a cable tie) as shown in Figures 8 and 9. Alternatively, other systems such as an adhesive element, a spacer with adhesive, a hook-and- loop strap (e.g. Velcro), circlip, bracket, or fastener. This interface member 4d may particularly be used where it is not possible to directly attach the optical element 3 to the elongate member 2.

[0221] The optical element 3 is attached to the interface member 4d with the connector(s) 4e. For example, this could be with one or more resilient arms which snap fit into the interface member 4d. Alternatively, the optical element 3 may slide into engagement with the interface member 4d, or any of the attachment systems discussed herein.

[0222] The optical element 3 and connectors 4e may be formed substantially integrally / unitary with one another. For example, the optical element 3 and connectors 4e may be formed of a single sheet of material which is shaped to form the optical element 3 and the connectors 4e. The optical element 3 and connectors 4e may be formed as a single piece through extrusion, 3D printing, or any other suitable manufacturing method.

[0223] The interface member 4d may be formed in any suitable manufacturing method, including injection moulding, extrusion, 3D printing, or the like.

[0224] Other examples of attachment elements 4 can be used with any of the examples discussed herein. For example, this could incorporate one or more of: an adhesive element, a spacer with

[0225] 30 adhesive, a hook-and-loop strap (e.g. Velcro), circlip, bracket, or fastener.

[0226] Figure 10 shows a third embodiment of a cover 1 , which can be referred to as a third cover 1. Unless otherwise expressly stated to the contrary, all features discussed in relation to the first PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0227] - 20 - cover 1 and / or the second cover 1 are equally applicable to the third cover 1 , and vice versa. The third cover 1 may include the optical element 3 of either of Figures 2 and 2A, or 3 and 3A.

[0228] Again, a different attachment element 4 is used in this cover 1. In this case, the attachment

[0229] 5 element(s) 4 are in the form of one or more clips. In the illustrated example, the attachment elements 4 comprise a first attachment element 4a and a second attachment element 4b, the first attachment element 4a being spaced from the second attachment element 4b in the first direction. That is, the attachment element 4 is in the form of a pair of clips configured to attach the optical element 3 to the elongate member 2.

[0230] An attachment axis 5 can be defined for these attachment elements 4 as an axis defined through a centre point of an opening 6a of one or more of the attachment elements 4, the opening being configured to receive the elongate member 2 in use. The attachment axis 5 may be generally parallel to the first direction. However, other attachment elements 4 may be used where this is not the case. The optical element 3 is shown arranged around the attachment axis 5 of the cover 2.

[0231] The clips have a concave seat 6 arranged to extend around the attachment axis 5 of the cover 1 , corresponding to the longitudinal axis 6 of the elongate member 2, the attachment axis 5 being parallel to the first direction. The cover 1 may be configured, for example by selection of appropriate dimensions of the attachment elements 4, such that the attachment axis 5 of the cover corresponds to the longitudinal axis 6 of the elongate member 2.

[0232] The concave seat 6 may be formed from a pair of resilient arms defining the opening 6a for receiving the elongate member 2 in use. The arms may be configured to snap fit onto the elongate member as shown in Figures 5 and 6. That is, the arms may be biased to a position with a spacing between the arms smaller than a reference dimension (such as a diameter) of the elongate member 2. As in the illustrated embodiment, the opening may be an arch-shaped cavity arranged to receive a cylindrical bar of a corresponding diameter, such that the arms

[0233] 30 resiliently grip onto the bar in use.

[0234] The attachment element(s) 4 may also comprise a spacer 4c and / or may be configured to position the optical element 3 at a separation distance 8 from a surface of the elongate member 2. The separation distance 8 may be uniform along the length of the cover 1. Each attachment PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0235] - 21 - member 4a, 4b may be have a same length as measured from the optical element 3 to the attachment axis 5. This separation distance can follow the disclosure herein in relation thereto.

[0236] The arc of the optical element 3 and / or cover 1 may be about this attachment axis 5.

[0237] 5

[0238] In the examples shown herein, a single cover 1 is shown attached to an elongate member 2. This may be any of the covers 1 discussed herein. In further examples, there may be a plurality of covers 1 attached to the elongate member 2, with each cover 1 at least partially overlapping along the longitudinal axis 6 of the elongate member 2. In such an example, each cover 1 may be rotationally offset about the longitudinal axis 6. Particularly, where there are N covers 1 overlapping along the longitudinal axis 6, the covers may be spaced from one another by (36O / N)0about the longitudinal axis 6. That is, they may be rotationally symmetric with N-fold symmetry.

[0239] In a further embodiment a kit is provided for covering a framework of elongate members, the kit comprising a plurality of covers according to any embodiment of the invention. The kit may comprise a set of covers having sizes and shapes configured to match the elongate members of a known framework, while being sized to minimise the extent of the covers into any gaps between the elongate members to thereby avoid disruption of an observer’s view through the framework.

[0240] In a further embodiment, a framework is provided comprising one or more elongate members and at least one cover according to any embodiment of the invention. An example of such a framework comprising a plurality of elongate members 2 and a plurality of covers 1 is shown in Figure 7. In the example shown in Figure 7, each of the covers 1 is as described above, and extends along one of the elongate members 2 and is secured thereto by its attachment elements 4. Each cover 1 is elongate in a direction which is parallel to an elongate direction of the elongate member 2 to which it is attached.

[0241] 30 The one or more elongate members 2 of the framework according to the present invention may form a security grille for a door or window, a crane framework, a scaffold, a pylon or similar. Each of the elongate members may be a bar or strut of the structure. PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0242] - 22 -

[0243] A further embodiment provides a method of obscuring the elongate member 2, the method comprising providing a cover according to any embodiment described herein and attaching the cover to the elongate member using the attachment member(s).

[0244] 5 When providing the cover, the elongate member may be measured to determine a width of the elongate member measured perpendicular to its longitudinal axis (elongate direction). A cover may be selected having a width which is no more than 2 times bigger than the width of the elongate member. In certain examples, A cover may be selected having a width which is no more than 1 .7 times bigger than the width of the elongate member.

[0245] The cover 1 may be manufactured by extrusion, or specifically, profile extrusion. A method of manufacturing the cover 1 comprises providing a die for extrusion, and passing heated material through the die to form the cover for attachment to the elongate member.

[0246] The die for extrusion comprises an aperture, which may be formed according to the desired end profile or cross-section of the cover 1. The aperture comprises undulations for forming the undulating surface(s) of the cover 1.

[0247] In some examples, the method of manufacturing the cover further comprises a secondary forming step. In these examples, the aperture of the die is not curved (or not fully shaped in the shape of the cover 1) and the extruded material from which the cover is formed is, prior to the secondary forming step, a substantially flat sheet (or partially curved sheet) on which the undulating surface(s) are formed. In these examples, manufacturing the cover may further comprise a step of thermoforming, pressure forming, or vacuum forming the extruded material to form the cover. In such examples, passing the material through the die may be an intermediary step in the manufacture of the cover 1 .

[0248] In some examples, the aperture may comprise a curved or arched portion for forming the optical element 3 of the cover 1 , and an attachment aperture portion for forming the attachment

[0249] 30 elements 4 of the cover 1 . As such, the cover, or at least the optical element, can be manufactured in a single step, with no need for further processing or forming.

[0250] The cover 1 may be formed from a resin material. For example, the cover 1 may be formed from a resin material having good outdoor weatherability, mechanical strength, and melt flow PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0251] - 23 - properties insuring good clarity after extrusion. The resin may be an acrylate resin. As an example, the resin may be polymethylmethacrylate.

[0252] While embodiments according to the present disclosure have been described above and

[0253] 5 illustrated in the drawings, these are for example only and are non-limiting. It will be appreciated by those skilled in the art that alternatives are possible within the ambit of the disclosure. For example, in the illustrated example, the optical element is a lenticular lens sheet. In any embodiment, the optical element may alternatively be any lens or array of lenses configured to redirect light to at least partially obscure the elongate member from at least one viewpoint.

[0254] In the present disclosure, the term lenticular lens refers to an array of lenses or lens elements (lenticules) configured to refract light. A lenticule is an individual lens or lens element, a plurality of which make up the lenticular lens. The lenticules may therefore be formed as ridges on the surface of the lenticular lens sheet. The lenticular lens may be characterised based on how many lenticules fit within an inch of the lens surface (lenticules per inch, LPI). In the present case, the lenticular screen may have 35 LPI or greater or40 LPI or greater. In certain cases, lower LPIs could be used. For example, with a 10” width elongate member 2, the LPI may be 0.5 LPI to 3 LPI. For a 0.5” width elongate member 2 the LPI may be at least 15 LPI.

[0255] In examples with a sinusoidal lens, LPI can refer to the number of lenses per inch (i.e. the number of convex peaks per inch).

[0256] In any embodiment, the elongate member may be, for example, a structural strut or bar, a security bar for a door or window, a framework element for a crane, scaffold or similar.

[0257] The cover(s) of the present invention may be attached to the inside of the security grille or other framework to obscure the bars from the point of view of an observer positioned on the inside of the bars, thereby allowing them to see the view through the window with limited obscuring of the view. Additionally, or alternatively, one or more covers may be attached on an outside of the

[0258] 30 grille or other framework to obscure them from the point of view of an external observer looking at the structure.

[0259] The cover of the present invention may be fitted during manufacture, or be retrofitted after installation of the elongate member, for example on a security bar or grille. The cover of the PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0260] - 24 - present invention may obscure the appearance of the elongate member while limiting disruption of a view beyond or through the structure (e.g. the window security grille) to which it is attached.

[0261] It is appreciated that in some cases, an elongate member may be too large (particularly in

[0262] 5 diameter) to be effectively visually obscured by a single cover 1 . In this sense, a composite cover may be defined. This composite cover may be formed of a plurality of covers 1 as discussed herein, attached to one another.

[0263] For example, the composite cover may comprise of a plurality of flat or curved panels (which may be covers 1 as discussed herein) with each panel being a cover for partially covering the large diameter elongate member. Each panel / cover 1 having an optical element configured to redirect light to at least partially obscure the elongate member from at least one viewpoint. Collectively, the composite cover may thus at least partially obscure the elongate member from at least one viewpoint.

[0264] Each panel / cover 1 may comprise one or more cover attachment elements, for attaching adjacent panels / covers 1 to one another. These cover attachment elements may be the same as the attachment elements 4 discussed above, or may be different. In an example, the cover attachment elements may be in the form of ridges (such as semi-circular ridges) along a cover edge. These ridges can allow for adjacent panels / covers 1 to snap together, and with multiple panels, eventually surround the elongate member.

[0265] There may also be some separation support structures similar to the structures 4b and 4c shown in Figure 9, which also may self-clamp to each other for additional support, rigidity, and wind resistance.

[0266] By providing a cover with an optical element and attachment element(s), the present invention may be securely fitted and simple to manufacture, while securely attaching the cover to the element it is configured to obscure.

[0267] 30

[0268] By using a lenticular lens as the optical element, the present invention may provide a lightweight and durable means of obscuring the elongate member. PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0269] - 25 -

[0270] CLAUSES

[0271] 1. A cover for attachment to an elongate member, the cover comprising: an optical element configured to redirect light to at least partially obscure the elongate member from at least one viewpoint; and

[0272] 5 at least one attachment element configured to attach the optical element to the elongate member.

[0273] 2. The cover of clause 1 wherein the optical element is a lens.

[0274] 3. The cover of any preceding clause wherein the optical element is a lenticular lens.

[0275] 4. The cover of any preceding clause wherein the optical element is elongate in a first direction.

[0276] 15 5. The cover of clause 4 wherein the optical element has a curved or arched cross- sectional profile in a plane arranged generally perpendicular to the first direction.

[0277] 6. The cover of clause 5 wherein the optical element extends through at least a 60 degree arc, preferably a 100 degree arc, more preferably a 120 degree arc.

[0278] 20

[0279] 7. The cover of any one of clauses 4 to 6 wherein the optical element is a lenticular lens and comprises a plurality of elongate lenticules, the lenticules being aligned parallel to the first direction.

[0280] 25 8. The cover of any preceding clause wherein the optical element is elongate in a first direction and: the at least one attachment element extends along a length of the optical element in the first direction; or the at least one attachment elements comprise a first attachment element and a second attachment element, the first attachment element being spaced from the second attachment element in the first direction.

[0281] 9. The cover of any preceding clause wherein the or each attachment element is configured to position the optical element at a separation distance from a surface of the

[0282] 35 elongate member; PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0283] - 26 - wherein optionally the separation distance is uniform along the length of the cover in the first direction.

[0284] 10. The cover of any preceding clause wherein the or each attachment element comprises a

[0285] 5 clip configured to snap fit onto the elongate member.

[0286] 11 . The cover of any preceding clause wherein the optical element is elongate in a first direction wherein the or each attachment element comprises a concave seat arranged to extend around an attachment axis corresponding to a longitudinal axis of the elongate member, the attachment axis being parallel to the first direction.

[0287] 12. The cover of any preceding clause, wherein the optical element comprises a primary optical element, and a plurality of secondary optical elements at an angle to the primary optical element, the primary optical element arranged between the secondary optical elements.

[0288] 13. The cover of any preceding clause, wherein the attachment element comprises an interface member configured to attach to the elongate member, and a connector configured to attach the optical element to the interface member.

[0289] 14. The cover of any preceding clause wherein the elongate member is one of: a structural strut or bar; or a security bar for a door or window.

[0290] 15. A method of obscuring an elongate member, the method comprising: providing a cover as in any preceding clause; and attaching the cover to the elongate member using the at least one attachment member.

[0291] 16. The method of clause 15 wherein providing the cover comprises determining a width of the elongate member measured perpendicular to its elongate direction and selecting a cover

[0292] 30 having a width which is no more than 2 times the width of the elongate member, preferably no more than 1 .7 times the width of the elongate member.

[0293] 17. The method of clause 15 or 16, wherein providing the cover comprises determining a separation distance at which the optical element is from a surface of the elongate member, a PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0294] - 27 - ratio of the separation distance to the width of the elongate member being between 8:13 and 18:13.

[0295] 18. A kit for covering a framework of elongate members, the kit comprising a plurality of

[0296] 5 covers according to any of clauses 1 to 14.

[0297] 19. A framework comprising: one or more elongate members; and at least one cover as in any of clauses 1 to 14; wherein each cover of the at least one covers extends along an elongate member of the one or more members and is secured thereto by the one or more attachment elements of the cover.

[0298] 20. The framework of clause 19 wherein each cover is elongate in a direction which is parallel to an elongate direction of the elongate member to which it is attached.

[0299] 21 . The framework of any one of clauses 19 to 20 wherein the one or more elongate members form: a security grille for a door or window, wherein each of the elongate members is a bar or strut of the security grille; or a crane framework, scaffold or pylon wherein each of the elongate members is a bar or strut.

[0300] 22. The framework of any one of clauses 19 to 21 wherein the cover is arranged to at least partially surround the elongate member.

[0301] 23. The framework of any one of clauses 19 to 22 wherein the cover has a width in a direction perpendicular to the first direction which is no more than 2 times the width of the elongate member in the same direction, preferably no more than 1 .7 times the width of the elongate member.

[0302] 30

[0303] 24. The framework of any one of clauses 19 to 23 wherein the one or more attachment elements of the or each cover are sized to snap-fit onto the elongate member to which it is attached. PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0304] - 28 -

[0305] 25. A cover for attachment to an elongate member, the cover having an inner side facing the elongate member in use, and an outer side opposite to the inner side, the cover comprising: an optical element configured to redirect light to at least partially obscure the elongate member from at least one viewpoint; and

[0306] 5 at least one attachment element configured to attach the optical element to the elongate member.

[0307] 26. The cover of clause 25 wherein the optical element is a lens.

[0308] 27. The cover of any of clauses 25 to 26 wherein the optical element is elongate in a first direction.

[0309] 28. The cover of clause 27 wherein the optical element has a curved or arched cross- sectional profile in a plane arranged generally perpendicular to the first direction.

[0310] 29. The cover of clause 28 wherein the optical element extends through at least a 60 degree arc, preferably a 100 degree arc, more preferably a 120 degree arc.

[0311] 30. The cover of any of clauses 25 to 29 wherein the optical element has a cross-section perpendicular to the first direction comprising a plurality of alternating peaks and troughs, the alternating peaks and troughs lying in at least one surface of the optical element, wherein preferably the alternating peaks and troughs form a plurality of repeating curves.

[0312] 31. The cover of any of clauses 25 to 30 wherein the optical element has a surface having undulations that extend perpendicular to the first direction.

[0313] 32. The cover of clause 30, wherein the optical element is a lenticular lens.

[0314] 33. The cover of clause 30 or 32, wherein the optical element comprises a plurality of

[0315] 30 elongate lenticules, the lenticules being aligned parallel to the first direction.

[0316] 34. The cover of clause 33 wherein at least some of the plurality of elongate lenticules are arranged on the inner side of the cover. PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0317] - 29 -

[0318] 35. The cover of clause 33 or 34 wherein at least some of the plurality of elongate lenticules are arranged on the outer side of the cover.

[0319] 36. The cover of clause 30, wherein the optical element comprises at least one undulating

[0320] 5 surface of the cover defining the peaks and the troughs.

[0321] 37. The cover of clause 31 or 36, wherein the at least one undulating surface defines a series of alternating convex and concave lenses.

[0322] 38. The cover of clause 31 , 36 or clause 37 wherein the at least one undulating surface of the cover is substantially sinusoidal the at least one undulating surface comprises an inner undulating surface formed on the inner side of the cover.

[0323] 39. The cover of any of clauses 31 or 36 to 38 wherein the at least one undulating surface comprises an outer undulating surface formed on the outer side of the cover.

[0324] 40. The cover of clause 39 when dependent on clause 38 wherein the inner undulating surface and the outer undulating surface are in phase such that the peaks of the inner undulating surface are aligned with the troughs of the outer undulating surface.

[0325] 41 . The cover of clause 39 when dependent on clause 38 wherein the inner undulating surface and the outer undulating surface are out of phase such that the peaks of the inner undulating surface are aligned with the peaks of the outer undulating surface.

[0326] 42. The cover of any of clauses 30 to 41 wherein the cover extends between a first cover edge and a second cover edge and wherein a distance between adjacent peaks decreases from a central region of the cover towards the first cover edge and the second cover edge.

[0327] 43. The cover of any of clauses 30 to 42 wherein the cover extends between a first cover

[0328] 30 edge and a second cover edge and wherein each peak has a peak amplitude being a height of the peak relative to an adjacent trough on that surface of the optical element, wherein the peak amplitude decreases from a central region of the cover towards the first cover edge and the second cover edge. PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0329] - 30 -

[0330] 44. The cover of any of clauses 25 to 43, wherein the cover has a minimum thickness measured from the inner side to the outer side, and wherein a focal length of the optical element is less than the minimum thickness of the cover.

[0331] 5 45. The cover of any of clauses 25 to 44, wherein the optical element is elongate in a first direction and: the at least one attachment element extends along a length of the optical element in the first direction; or the at least one attachment elements comprise a first attachment element and a second attachment element, the first attachment element being spaced from the second attachment element in the first direction.

[0332] 46. The cover of any of clauses 25 to 45, wherein the or each attachment element is configured to position the optical element at a separation distance from a surface of the

[0333] 15 elongate member; wherein optionally the separation distance is uniform along the length of the cover in the first direction.

[0334] 47. The cover of clause 46, wherein the separation distance is between 20 mm and 4 mm.

[0335] 20

[0336] 48. The cover of any of clauses 25 to 47, wherein the frequency of the peaks is between 15 per inch and 300 per inch, preferably between 20 per inch and 150 per inch.

[0337] 49. The cover of any of clauses 25 to 48, wherein the or each attachment element

[0338] 25 comprises a clip configured to snap fit onto the elongate member.

[0339] 50. The cover of any of clauses 25 to 49, wherein the optical element is elongate in a first direction wherein the or each attachment element comprises a concave seat arranged to extend around an attachment axis corresponding to a longitudinal axis of the elongate member, the attachment axis being parallel to the first direction.

[0340] 51 . The cover of any of clauses 25 to 50, wherein the optical element comprises a primary optical element, and a plurality of secondary optical elements at an angle to the primary optical element, the primary optical element arranged between the secondary optical elements.

[0341] 35 PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0342] - 31 -

[0343] 52. The cover of any of clauses 25 to 51 , wherein the attachment element comprises an interface member configured to attach to the elongate member, and a connector configured to attach the optical element to the interface member.

[0344] 5 53. The cover of any of clauses 25 to 51 , wherein the elongate member is one of: a structural strut or bar; or a security bar for a door or window.

[0345] 54. A method of obscuring an elongate member, the method comprising: providing a cover according to any of clauses 25 to 53; and attaching the cover to the elongate member using the at least one attachment member.

[0346] 55. The method of clause 54, wherein providing the cover comprises determining a width of the elongate member measured perpendicular to its elongate direction and selecting a cover having a width which is no more than 2 times the width of the elongate member, preferably no more than 1 .7 times the width of the elongate member.

[0347] 56. The method of clause 54 or 55, wherein providing the cover comprises determining a separation distance at which the optical element is from a surface of the elongate member, a ratio of the separation distance to the width of the elongate member being between 8:13 and 18:13.

[0348] 57. A kit for covering a framework of elongate members, the kit comprising a plurality of covers according to any of clauses 25 to 53.

[0349] 58. A framework comprising: one or more elongate members; and at least one cover according to any of clauses 25 to 53; wherein each cover of the at least one covers extends along an elongate member of the one or

[0350] 30 more members and is secured thereto by the one or more attachment elements of the cover.

[0351] 59. The framework of clause 58, wherein each cover is elongate in a direction which is parallel to an elongate direction of the elongate member to which it is attached. PCT / US25 / 49605 06 October 2025 (06.10.2025)

[0352] - 32 -

[0353] 60. The framework of any one of clauses 58 to 59, wherein the one or more elongate members form: a security grille for a door or window, wherein each of the elongate members is a bar or strut of the security grille; or

[0354] 5 a crane framework, scaffold or pylon wherein each of the elongate members is a bar or strut.

[0355] 61 . The framework of any one of clauses 58 to 60 wherein the cover is arranged to at least partially surround the elongate member.

[0356] 62. The framework of any one of clauses 58 to 61 wherein the cover has a width in a direction perpendicular to the first direction which is no more than 2 times the width of the elongate member in the same direction, preferably no more than 1 .7 times the width of the elongate member.

[0357] 63. The framework of any one of clauses 58 to 62 wherein the one or more attachment elements of the or each cover are sized to snap-fit onto the elongate member to which it is attached.

[0358] 64. A method of manufacturing a cover for attachment to an elongate member according to any of clauses 25 to 53, the method comprising providing a die for extrusion; and passing heated material through an aperture of the die to form the cover for attachment to the elongate member; wherein the aperture of the die is shaped with undulations.

[0359] 65. The method of clause 64, wherein aperture of the die comprises a curved or arched portion for forming the optical element of the cover.

[0360] 30 66. The method of clause 64 or 65, wherein the aperture of the die comprises an attachment aperture portion for forming the attachment elements.

Claims

1.PCT / US25 / 49605 06 October 2025 (06.10.2025)- 33 -CLAIMS:1 1. A cover for attachment to an elongate member, the cover having an inner side facing the2 elongate member in use, and an outer side opposite to the inner side, the cover comprising:3 an optical element configured to redirect light to at least partially obscure the elongate4 member from at least one viewpoint; and5 at least one attachment element configured to attach the optical element to the elongate6 member.1 2. The cover of claim 1 wherein the optical element is a lens.1 3. The cover of any preceding claim wherein the optical element is elongate in a first2 direction.1 4. The cover of claim 3 wherein the optical element has a curved or arched cross-sectional2 profile in a plane arranged generally perpendicular to the first direction.1 5. The cover of claim 4 wherein the optical element extends through at least a 60 degree2 arc, preferably a 100 degree arc, more preferably a 120 degree arc.1 6. The cover of any preceding claim wherein the optical element has a cross-section2 perpendicular to the first direction comprising a plurality of alternating peaks and troughs, the3 alternating peaks and troughs lying in at least one surface of the optical element, wherein4 preferably the alternating peaks and troughs form a plurality of repeating curves.1 7. The cover of any preceding claim wherein the optical element has a surface having2 undulations that extend perpendicular to the first direction.1 8. The cover of claim 6, wherein the optical element is a lenticular lens.1 9. The cover of claim 6 or 8, wherein the optical element comprises a plurality of elongate2 lenticules, the lenticules being aligned parallel to the first direction.1 10. The cover of claim 9 wherein at least some of the plurality of elongate lenticules are2 arranged on the inner side of the cover.PCT / US25 / 49605 06 October 2025 (06.10.2025)- 34 -1 11 . The cover of claim 9 or 10 wherein at least some of the plurality of elongate lenticules2 are arranged on the outer side of the cover.1 12. The cover of claim 6, wherein the optical element comprises at least one undulating2 surface of the cover defining the peaks and the troughs.1 13. The cover of claim 7 or 12, wherein the at least one undulating surface defines a series2 of alternating convex and concave lenses.1 14. The cover of claim 7, 12 or claim 13 wherein the at least one undulating surface of the2 cover is substantially sinusoidal the at least one undulating surface comprises an inner3 undulating surface formed on the inner side of the cover.1 15. The cover of any of claims 7 or 12 to 14 wherein the at least one undulating surface2 comprises an outer undulating surface formed on the outer side of the cover.1 16. The cover of claim 15 when dependent on claim 14 wherein the inner undulating surface2 and the outer undulating surface are in phase such that the peaks of the inner undulating3 surface are aligned with the troughs of the outer undulating surface.1 17. The cover of claim 15 when dependent on claim 14 wherein the inner undulating surface2 and the outer undulating surface are out of phase such that the peaks of the inner undulating3 surface are aligned with the peaks of the outer undulating surface.1 18. The cover of any of claims 6 to 17 wherein the cover extends between a first cover edge2 and a second cover edge and wherein3 a distance between adjacent peaks decreases from a central region of the cover towards4 the first cover edge and the second cover edge.1 19. The cover of any of claims 6 to 18 wherein the cover extends between a first cover edge2 and a second cover edge and wherein each peak has a peak amplitude being a height of the3 peak relative to an adjacent trough on that surface of the optical element, wherein the peak4 amplitude decreases from a central region of the cover towards the first cover edge and the5 second cover edge.PCT / US25 / 49605 06 October 2025 (06.10.2025)- 35 -1 20. The cover of any preceding claim, wherein the cover has a minimum thickness2 measured from the inner side to the outer side, and wherein a focal length of the optical element3 is less than the minimum thickness of the cover.1 21 . The cover of any preceding claim, wherein the optical element is elongate in a first2 direction and:3 the at least one attachment element extends along a length of the optical element in the4 first direction; or5 the at least one attachment elements comprise a first attachment element and a second6 attachment element, the first attachment element being spaced from the second attachment7 element in the first direction.1 22. The cover of any preceding claim, wherein the or each attachment element is configured2 to position the optical element at a separation distance from a surface of the elongate member;3 wherein optionally the separation distance is uniform along the length of the cover in the4 first direction.1 23. The cover of claim 22, wherein the separation distance is between 20 mm and 4 mm.1 24. The cover of claim 23 wherein the frequency of the peaks is between 15 per inch and2 300 per inch, preferably between 20 per inch and 150 per inch.1 25. The cover of any preceding claim, wherein the or each attachment element comprises a2 clip configured to snap fit onto the elongate member.1 26. The cover of any preceding claim, wherein the optical element is elongate in a first2 direction wherein the or each attachment element comprises a concave seat arranged to extend3 around an attachment axis corresponding to a longitudinal axis of the elongate member, the4 attachment axis being parallel to the first direction.1 27. The cover of any preceding claim, wherein the optical element comprises a primary2 optical element, and a plurality of secondary optical elements at an angle to the primary optical3 element, the primary optical element arranged between the secondary optical elements.PCT / US25 / 49605 06 October 2025 (06.10.2025)- 36 -1 28. The cover of any preceding claim, wherein the attachment element comprises an2 interface member configured to attach to the elongate member, and a connector configured to3 attach the optical element to the interface member.1 29. The cover of any preceding claim wherein the elongate member is one of:2 a structural strut or bar; or3 a security bar for a door or window.1 30. A method of obscuring an elongate member, the method comprising:2 providing a cover according to any preceding claim; and3 attaching the cover to the elongate member using the at least one attachment member.1 31 . The method of claim 30, wherein providing the cover comprises determining2 a width of the elongate member measured perpendicular to its elongate direction and3 selecting a cover having a width which is no more than 2 times the width of the elongate4 member, preferably no more than 1.7 times the width of the elongate member.1 31 . The method of claim 30 or 31 , wherein providing the cover comprises determining a2 separation distance at which the optical element is from a surface of the elongate member, a3 ratio of the separation distance to the width of the elongate member being between 8:13 and4 18:13.1 32. A kit for covering a framework of elongate members, the kit comprising a plurality of2 covers according to any of claims 1 to 29.1 33. A framework comprising:2 one or more elongate members; and3 at least one cover according to in any of claims 1 to 29;4 wherein each cover of the at least one covers extends along an elongate member of the one or5 more members and is secured thereto by the one or more attachment elements of the cover.1 34. The framework of claim 33, wherein each cover is elongate in a direction which is2 parallel to an elongate direction of the elongate member to which it is attached.PCT / US25 / 49605 06 October 2025 (06.10.2025)- 37 -1 35. The framework of any one of claims 33 to 34, wherein the one or more elongate2 members form:3 a security grille for a door or window, wherein each of the elongate members is a bar or4 strut of the security grille; or5 a crane framework, scaffold or pylon wherein each of the elongate members is a bar or6 strut.1 36. The framework of any one of claims 33 to 35 wherein the cover is arranged to at least2 partially surround the elongate member.1 37. The framework of any one of claims 33 to 36 wherein the cover has a width in a direction2 perpendicular to the first direction which is no more than 2 times the width of the elongate3 member in the same direction, preferably no more than 1 .7 times the width of the elongate4 member.1 38. The framework of any one of claims 33 to 36 wherein the one or more attachment2 elements of the or each cover are sized to snap-fit onto the elongate member to which it is3 attached.1 39. A method of manufacturing a cover for attachment to an elongate member according to2 any of claims 1 to 29, the method comprising3 providing a die for extrusion; and4 passing heated material through an aperture of the die to form the cover for attachment5 to the elongate member;6 wherein the aperture of the die is shaped with undulations.1 40. The method of claim 39, wherein aperture of the die comprises a curved or arched2 portion for forming the optical element of the cover.1 41 . The method of claim 39 or 40, wherein the aperture of the die comprises an attachment2 aperture portion for forming the attachment elements.

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