GB2301694A - Improvements in or relating to light boxes - Google Patents

Abstract

A light box, for displaying transparencies by back lighting, for example for advertising, includes a backing assembly 14 (Figure 1) and a cover assembly 26, 28, 30 including a clear transparent panel 26 against which the transparency 60 to be displayed can be placed. The cover assembly 26, 28, 30 may be arranged simply to hook onto or lift off from the backing assembly 14. The clear transparent panel 26 may be curved so as to be convex outwardly and the cover assembly may afford inwardly directed recesses at opposite ends of the transparent panel, to locate the ends of a flexible resilient light-transmitting plastics sheet 66 extended around the inner surface of the transparent panel 26 or around the inner surface of a transparency 60 laid, in turn, against the inner surface of the transparent panel 26. The backing assembly 14 may be adapted to be secured to a wall or to some other support. In some embodiments, the backing assembly is free standing or is freely suspended and carries a respective cover assembly on either of two opposite sides thereof (Figures 13A and 13B). The clear transparent panel 26 may have other non-convex shapes, (Figure 6A-F).

Description

DESCRIPTION OF INVENTION Title: "Improvements in or relating to light boxes" THIS INVENTION relates to so-called light boxes which are used for displaying transparencies by back-lighting for advertising or informational purposes.

Figure 12 of the accompanying drawings illustrates schematically a typical conventional light box. This comprises an open fronted box structure 100 secured to a building wall, a frame structure 102 detachably fitted to the open front of the box and transparent and translucent panels 104 held in the frame structure and holding between them a transparency (not shown) bearing desired advertising material between such panels. Electric lamps 106 and associated electrical circuitry (not shown) are mounted within the box-like structure 100 for back-lighting the transparency. Known light boxes such as shown in Figure 12 do not and cannot provide unobstructed display from wall surface to wall surface for advertising or informational material, for the box structure itself presents unused visible areas.That is to say, in a conventional light box such as shown in Figure 12, the transparent outer panel, or the portion thereof which can usefully serve for the display of a back-lit transparency, is limited in size relative to the light box as a whole, and there are relatively large areas of the visible outer surface of the light box which, in visual terms, serve no useful purpose.

It is an object of the present invention to provide a light box construction which is capable of providing unobstructed display from wall surface to wall surface, and in which visible areas which cannot serve any useful visual or display surface are minimised.

According to one aspect of the invention, there is provided a light box including a cover box or cover assembly affording a clear transparent panel which is curved so as to be convex outwardly and further affording inwardly directed recesses at opposite ends of the transparent panel, the cover assembly further including a flexible resilient light-transmitting plastics panel of a size to fit snugly against the inner surface of said transparent panel, or against a transparency laid against said inner surface, the flexible panel having formations at its ends to lodge releasably in said recesses to retain said flexible panel releasably in position.

In a preferred embodiment of the invention, the light box includes a back structure adapted to be secured to a planar wall surface and said transparent panel, when the cover assembly is mounted on the backing assembly, extends at each end to a respective position substantially in the plane of said wall. In this preferred embodiment, said recesses are provided by flanges each extending from a respective said end of the transparent panel towards the other said end, said flanges having co-planar rear surfaces substantially coincident with the plane of such wall, each said recess being defined by the corner region between the respective said flange and the adjoining end portion of said transparent panel.

According to another aspect of the invention there is provided a light box including a backing assembly adapted to be secured to a vertical wall and a cover assembly having edges for engagement with or close juxtaposition with said wall when the cover assembly is mounted on the backing assembly, and wherein said backing assembly includes a part or parts arranged to engage the surface of such wall when the backing assembly is secured thereto, and further includes, along an upper edge of the backing assembly, an upwardly extending flange which at least at its upper free edge is spaced from such wall surface, and wherein the cover assembly includes, along an upper edge thereof, an inwardly and downwardly extending flange for engagement behind said flange of the backing assembly whereby the cover assembly is suspended from the backing assembly by said flanges and can be fitted to and removed from the backing assembly by hooking on or lifting off from said backing assembly flange.

Preferably, releasable retaining means is provided which, in a retaining position thereof, prevents the cover assembly being lifted for unhooking from said flange of the backing plate.

Thus, in preferred embodiments of the invention, a front box structure, providing the light transmitting display area, is removably fitted to a panel fixed to the wall or the like, in contrast to the conventional arrangement in which a light transmitting panel forms a removable front cover to a box structure secured to the wall. This reversal of the conventional arrangement makes it possible for a light box embodying the invention to provide an unobstructed wall-to-wall display. It will be appreciated that for aesthetic reasons, a light box embodying the present invention may be made to simulate the appearance of a conventional light box, but in such a case this appearance is not forced on the designer by constructional limitation as is the case in conventional light boxes.

Embodiments of the invention are described below by way of example with reference to the accompanying drawings, in which: FIGURE 1 is a perspective view of a backing assembly forming part of a light box embodying the invention, FIGURE 2 is a perspective view of a cover assembly forming part of the same light box as the backing assembly of Figure 1; FIGURE 3 is a schematic side view illustrating the mounting of the cover assembly of Figure 2 on the backing assembly of Figure 1; FIGURE 4 is a view similar to Figure 3 but showing a further stage in the procedure for mounting the cover assembly; FIGURE 5 is a view similar to Figure 4 but showing the final stage in the mounting procedure and also showing part of a lighting installation; FIGURE 6 shows, at A to F, six variant light boxes embodying the invention;; FIGURE 7 shows in vertical section, and FIGURE 8 shows in perspective view from above, a variant of the light box of Figures 1 to 5; FIGURES 9a to 9f are fragmentary views in vertical section showing the mounting of the cover assembly on the backing assembly in the light box of Figures 1 to 5; FIGURE 10 is a schematic fragmentary view in horizontal section through the light box of Figures 1 to 5, FIGURES lia to lld illustrate various alternative ways of forming joints between panel portions in the cover assembly, and FIGURE 12 is an exploded perspective view of a conventional light box.

Referring to the drawings, a light box embodying the invention comprises two main parts, namely a backing assembly 10, shown in Figure 1, and a cover assembly 12, shown in Figure 2.

The backing assembly may simply comprise a metal or plastics plate 14, the major part of which is planar and lies flat against a vertical wall or panel (not shown) to which the plate 14 is secured, for example by screws, brackets or clips (not shown). The vertical wall in question may, for example, be an interior wall of a shop or supermarket, or of a public building, or may be, for example, an end wall or panel of a display gondola or other display structure in a shop of supermarket. It is envisaged that the plate 14 may be fitted with hooks engageable in the slots in so-called slat panels which are well known in retail outlets and which provide a series of "T" section slots to receive such hooks. The plate 14 may have such hooks permanently fitted but preferably the plate 14 is merely provided with slots each adapted to receive one end of such a hook, of sheet metal, for example, the other end of which is adapted to engage in such a "T" section slot in slat panelling. In this way, the same plate 14 may be adapted to be screwed to a wall or to be mounted on a slat panel. A light box embodying the invention could equally well, if appropriately weatherproofed, be mounted on the outside of a building.

A horizontal flange 16 extends along the lower edge of plate 14 and a flange 18 extends upwardly, at an angle to the vertical from the upper edge of the plate 14. The flanges 16 and 18, as shown, stop short of the vertical edges of the plate 14. An angled metal plate 20 secured to the front surface of plate 14, for example by spot-welding, supports ballast units for fluorescent light units including light tubes 22 supported in clips also secured to the front of plate 14. Further plates, such as indicated at 24, may be secured to plate 14 for stiffening or support purposes.

The cover assembly illustrated in Figure 2 is preferably fabricated in its entirety from transparent rigid plastics sheet material such as "Perspex" or acrylic sheet and comprises a front panel 26 formed by a single transparent plastics sheet bent in a horizontal plane to the outwardly convex form shown in Figures 2, 6A and 10, a planar, horizontal top panel 28, a similar, planar horizontal bottom panel 30, a top flange 32 and side flanges 34. The panels 28 and 30 have convexly curved front edges to which the upper and lower edges of the panel 26 are secured, for example adhesively bonded. The flanges 32 and 34 lie in a common plane which corresponds substantially, in the erected condition of the light box, to the plane of the wall surface to which the light box is secured.It will be appreciated from this and from the description which follows that, in said erected condition the panel 26 extends from the supporting wall surface on one side of the box to the supporting wall surface on the other side of the box. The top panel 28 and bottom panel 30 are preferably opaque.

As best shown in Figure 10, each side flange 34 is bonded along one edge thereof to the inner surface of panel 26 at the respective vertical edge of panel 26 and extends inwardly from the panel 26, that is to say towards the other side flange 34. Likewise, the flange 32, co-planar with flanges 34, is bonded at its upper edge to the underside of panel 28 at the rear edge of the latter and extends downwardly therefrom. Keyhole openings 40 are formed through the flanges 34 inwardly of the vertical edges of panel 26 to receive spigots 47 of mushroom or screw-head shape projecting from plate 14 adjacent the vertical edges of the latter. It should be understood that such keyhole openings 40 in flanges 34, and the cooperating spigots 47, are necessary or desirable only when the light box is relatively large.For relatively small light boxes, the cover assembly, even when made of plastics sheet of relatively light gauge, is generally stiff enough to ensure that the edges of the cover assembly will remain close to the wall, without bowing or sagging, when the cover assembly is mounted, without the need for such openings 40 or spigots 47.

To fit the cover assembly to the back assembly, the flange 32 is hooked over the flange 18 (as shown in Figure 3) and is lowered towards the wall to encompass the plate 14, the panel 30 swinging below the flange 16. With the flanges 34 close to the plate 14, the assembly 12 is raised slightly (see Figure 4) to align the larger-diameter portions of the keyhole openings 40 with the spigots 47 and the assembly 12 is pushed against the plate 14 so that the spigots 47 pass through the keyhole apertures 40 and the flanges 34 engage the front surface of plate 14. The cover assembly 12 is then allowed to drop so that the narrower portions of the keyhole slots 40 pass around the shanks of the spigots 47 and the lower edge of the flange 32 drops into the downwardly narrowing gap between the wall and the flange 18.

As best shown in Figures 9c and 9d, means is provided at the lower end of the cover assembly for retaining the cover assembly in the fitted position described. This means comprises a plurality of locking screws 50 screw-threadedly engaged in screw-threaded bores in the panel 30 and reinforcing plates 52 bonded to the panel 30. Prior to fitting the cover assembly 12 the locking screws 50 are unscrewed until they occupy the positions shown in Figure 9c. After fitting the cover assembly, the screws 50 are screwed up into the positions shown in Figure 9, in which the upper ends of the screws 50 engage, or lie close to, the underside of the flange 16.

Accordingly, in this position, the screws 50 prevent the cover assembly from being lifted sufficiently for detachment from the back assembly. The arrangement is preferably such that in the latter position, shown in Figure 9d, the countersunk heads of the screws 50 are engaged unobtrusively in countersunk recesses in the underside of panel 30.

The cover assembly is adapted to receive a transparency in the form of a rectangular flexible sheet of a size and shape corresponding substantially with that of the internal surface of panel 26. Accordingly, the transparency, indicated at 60 in Figure 10 can be fitted against the inner surface of the panel 26 with the upper and lower horizontal edges closely adjoining the upper and lower panels 28 and 30, and with each vertical edge of the transparency engaged in the vertex of the angle between the respective flange 34 and the panel 26. The transparency is held in this position by a resilient but relatively stiff, light transmitting (e.g. light diffusing) plastics sheet 66 which engages the rear surface of the transparency and is braced between the two flanges 34.The sheet 66 is of substantially the same height as the transparency, i.e. as the inner surface of the panel 26, but has its lateral edges curled as illustrated in Figure 10 to form, in effect, a combined spring and gripping tab to allow the lateral edges of the sheet 66 to be extracted from the respective recess between the respective flange 34 and panel 26.

The arrangement described allows the light from the fluorescent light tubes 22 to illuminate the transparency 60 substantially evenly over its entire extent, the backlit transparency occupying substantially the whole of the panel 26, extending from the wall at one edge of the light box to the wall at the other edge. The panels 28 and 30 are preferably of opaque plastics.

The arrangement described allows the one-piece front assembly easily to be fixed and removed by one person in one easy movement. Even where the light box is very large in size, such that the size and weight of the cover assembly make it difficult for a single person to lift and manoeuvre, once the cover assembly has been demounted from the backing assembly, the transparency 60 can easily and quickly be removed and replaced by one person.

The fabricated cover assembly allows for the easy cleaning and removal of dust particles from inside the face panel 26 and also from inside the inner transparency retaining panel 66 after the cover assembly has been removed from the wall.

It will be appreciated that, depending upon the type of lighting selected, the overall size of the assembly, etc., a certain amount of ventilation of the light box may be necessary for the removal of heat from the electric lamps and associated electrical components within the light box. The construction illustrated in the Figures allows such ventilation whilst avoiding the emission of light through ventilation apertures provided in the light box or the consequent production of undesired light patterns or spots on adjoining surfaces.Thus, as best shown in Figure 9f, an entrance for air into the light box from the bottom of the light box is provided by the spacing of the rear edge of panel 30 from the wall surface (by the thickness of the plate 14 if said rear edge is co-planar with the rear surfaces of flanges 34, although clearly a wider gap between the rear edge of panel 30 and the wall could be provided by off-setting said rear edge relative to the plane of the rear surfaces of flanges 34.Passages for exit of air from the upper end of the light box may be afforded, as illustrated in Figure 9, by providing apertures 68 in the angled flange 18, at intervals therealong and providing corresponding apertures 70 in the panel 28, adjacent the rear edge of the latter, i.e. in the region which lies rearwardly of the upper edge of the flange 18 when the cover assembly is fitted to the backing assembly. The apertures 70 are staggered with respect to the apertures 68 and the spacing between apertures 68 and between apertures 70 is such as to preclude the possibility of light passing through an aperture 68 and an aperture 70 from any brightly lit area within the light box.The arrangement described allows circulation of air through the light box by convection, the air entering through the gap between the rear edge of the panel 30 and the wall and exiting through the apertures 68 and the apertures 70.

As shown in Figures 6A to 6F, 7 and 8, the cover assembly may be of various shapes, apart from that described with reference to Figure 2 (which corresponds substantially with the shape shown in Figure 6A). The cover assembly shown in Figure 6D is, in effect, the cover assembly of Figures 2 and 6A turned on its side, so that the front panel extends in a curve from a position, at the top of the box, adjacent the wall on which the box is mounted to a position, at the bottom of the box, adjacent the wall, with, for example, flat opaque side walls corresponding to panels 28 and 30. With this arrangement, a modified back assembly is required, of course, without the flanges 16 and 18, and the side panels in this case carry the flanges, corresponding to flanges 34, bearing the keyhole-shaped apertures to engage over the spigots at the sides of the backing assembly.In this case, also, modified arrangements for ventilation may be necessary.

For example, ventilation may simply be achieved by the spacing of both the upper and the lower edges of the curved main panel of the cover assembly from the wall.

Figure 6B illustrates a variant of the cover assembly of Figure 6A in which the transparent main panel has a central outwardly concave region merging into convex regions at either side, which extend to adjacent the supporting wall surface.

Figures 7 and 8 illustrate an arrangement which differs from that of Figures 2 and 6A in that the cover assembly is wedge-shaped in vertical section, being substantially deeper at the top than at the bottom so that the outer surface of the panel 26 is inclined downwardly.

It should be noted that this variety of shapes and configurations of cover assembly is only practicable because each cover assembly is a unitary box-like assembly.

Composite structures of these shapes, which needed to be disassembled and re-assembled for replacement of transparencies or of light bulbs or tubes, would be quite impracticable.

This arrangement is suitable for light boxes to be located significantly above eye level.

Whilst it is preferred, in order to maximise display area, for the transparent display panel to extend in a curve, as a unitary surface, from wall to wall, it is also possible for the display surface to be broken into a plurality of distinct display surfaces connected by edges, as, for example, in Figures 6C and 6E, where a transparent front panel is connected at each side, by a respective edge, with a respective side panel. The side panels may be used to display distinct transparencies or to display transparencies which are effectively extensions of that displayed in the main, front panel. In Figure 6E, the light box is substantially in the form of a right parallelepiped. In Figure 6C, the front panel of the light box is outwardly concave, as are the outer edges of the upper and lower panels. In both Figures 6C and 6E the upper and lower panels are opaque.In the variant shown in Figure 6F, of the light box of Figure 6E, the top and bottom panels and side panels are opaque and of one colour with a border region of the otherwise-transparent front panel, and the front panel is outwardly convex, so that the light box presents the appearance of a television set.

In order to minimise the visual effect of the fabricated glue lines of the cover assembly the edges may be bevelled in various ways depending on shape size and thickness of plastics used. Figures lla to lld show various forms of bevelling which may be used.

Cover assemblies with flat sides can be illuminated at the sides with only a glue line showing (cf Figures 6A, 6B, 6C and 6E) or as a design feature the vertical corners in arrangements otherwise as shown in Figures 6C and 6E can be covered with a black outline separating the front panel from the side panels.

It should be noted that conventional light boxes, such as shown in Figure 12, besides suffering from the disadvantage of being unable to provide unobstructed wallto-wall display of advertising or informational material also suffer from various other disadvantages which are avoided or mitigated by the structures shown in, and described with reference to, Figures 1 to 11. Thus, in such known light boxes, removal and refitting of the frame structure, for example for replacement of the transparency or even changing the light bulbs or tubes within the box, is time consuming and labour intensive. In such known light boxes it is difficult to keep dust-free the surfaces through which light passes, including the transparency surfaces and the rear surface of the transparent outer panel, so that dust particles, trapped insects, etc. are visible in the display area, for example through or in front of the transparency.

Furthermore, in known light boxes the arrangements provided for supporting the transparencies are often awkward to use, when transparencies are changed.

It will be appreciated that other arrangements apart from those described for supporting the cover assembly from the backing assembly may be adopted. Thus, various hooking or retaining arrangements may be used instead.

A further variant comprises, in effect, two similar (indeed preferably identical) light boxes according to any of Figures 1 to lld arranged back to back, to form a composite display which can be located in the middle of an open space for viewing from any position within the whole 360C range of positions around the display. Figure 13a is a diagrammatic perspective view illustrating such a composite display suspended by wires, chains or cables 90 whilst Figure 13b is a corresponding view illustrating such a composite display mounted at the upper end of a post or stand 92. Reference 94 in both Figures indicates an electrical flex leading to a power supply point (not shown).Such a composite display may, indeed, simply be formed by bolting or welding together the backing plates 14 of two display boxes, in back-to-back, registering relation, possibly with the interposition of a supporting bracket or plate affording anchorage points by which the display may be suspended by wires or the like from a ceiling or other structure or may be secured to the upper end of a mounting mast or stand or the like. In this case, the backing plates, with any intervening supporting brackets or plates, form a core assembly, on either side of which the respective cover assemblies are mounted so that the edges of each cover assembly which, in the wall mounted equivalent, would lie against or close to the wall, lie against or close to the corresponding edges of the other cover assembly. It will be understood that if desired, the core assembly could be a dedicated assembly, that is to say it need not be formed by securing together two backing plates from wall-mounted boxes but may, for instance, comprise a single plate having two spaced apart mounting flanges at its upper end.

Claims (8)

1. A light box including a cover box or cover assembly affording a clear transparent panel which is curved so as to be convex outwardly and further affording inwardly directed recesses at opposite ends of the transparent panel, the cover assembly further including a flexible resilient light-transmitting plastics panel of a size to fit snugly against the inner surface of said transparent panel, or against a transparency laid against said inner surface, the flexible panel having formations at its ends to lodge releasably in said recesses to retain said flexible panel releasably in position.

2. A light box according to claim 1 which includes a back structure adapted to be secured to a planar wall surface and said transparent panel, when the cover assembly is mounted on the backing assembly, extends at each end to a respective position substantially in the plane of said wall.

3. A light box according to claim 2, wherein said recesses are provided by flanges each extending from a respective said end of the transparent panel towards the other said end, said flanges having co-planar rear surfaces substantially coincident with the plane of such wall, each said recess being defined by the corner region between the respective said flange and the adjoining end portion of said transparent panel.

4. A light box including a backing assembly adapted to be secured to a vertical wall and a cover assembly having edges for engagement with or close juxtaposition with said wall when the cover assembly is mounted on the backing assembly, and wherein said backing assembly includes a part or parts arranged to engage the surface of such wall when the backing assembly is secured thereto, and further includes, along an upper edge of the backing assembly, an upwardly extending flange which at least at its upper free edge is spaced from such wall surface, and wherein the cover assembly includes, along an upper edge thereof, an inwardly and downwardly extending flange for engagement behind said flange of the backing assembly whereby the cover assembly is suspended from the backing assembly by said flanges and can be fitted to and removed from the backing assembly by hooking on or lifting off from said backing assembly flange.

5. A light box according to claim 4 wherein releasable retaining means is provided which, in a retaining position thereof, prevents the cover assembly being lifted for unhooking from said flange of the backing plate.

6. A light box including a core assembly adapted to be suspended from a ceiling or other support or mounted on a supporting column, stand, or the like, the light box including two cover assemblies each having edges for engagement with or close juxtaposition with the corresponding edges of the other cover assembly when the cover assemblies are mounted on the core assembly, and wherein said core assembly provides, along an upper edge thereof, respective upwardly extending flanges which at least at their upper free edges are spaced from one another, and wherein each cover assembly includes, along an upper edge thereof, an inwardly and downwardly extending flange for engagement behind the respective said flange of the backing assembly whereby each cover assembly is suspended from the core assembly by said flanges and can be fitted to or removed from the core assembly by hooking on or lifting off from the respective said core assembly flange.

7. A light box substantially as hereinbefore described with reference to and as shown in any of the accompanying drawings.

8. Any novel feature or combination of features described herein.