[0001] The present invention is related to flush mounted inset lights for airport runways, taxiways and other air traffic lanes. In particular, the invention is related to in-pavement containers and housings which accept and support the inset lights.

[0002] A known problem in containers of the above type is that the height adjustment during construction or repair of the runway or taxiway is time- consuming. Since the inset lights must be mounted flush with the pavement or ground level, care must be taken to accurately position the containers for the inset lights relative to the (future) runway or taxiway level.

[0003] It is known from EP 021946 and from US 2005/030738 to make the container adjustable in height by providing a threaded extension sleeve which engages an internally threaded flange arranged at the top of the container. The extension sleeve can be rotated to the desired height and secured in that position by radially oriented screws frictionally engaging the container. The extension sleeve comprises a support flange at the top on which the inset light fixture is supported and to which it can be secured.

[0004] Containers of the above type have a number of cable entry locations, regularly distributed along the container's perimeter. Furthermore, the top of the container is typically provided with a marking for indicating the axis or centre line of the runway or taxiway and preventing the inset light to be mounted in an incorrect orientation. The marking is aligned during installation of the container, which operation is generally referred to as azimuth correction. However, the azimuth correction also alters the orientation of the cable entry locations, in turn requiring cable conduits to be repositioned. Since an airport may comprise thousands of flush mounted lights, repositioning the cable conduits substantially increases the total cable length that needs to be laid, which increases installation costs.

[0005] The above mentioned containers with extension sleeves cannot solve this problem adequately, since a rotation of the extension sleeve for azimuth correction necessarily changes the height of the container due to the threaded engagement. A known option is to use spacers or shims to adjust the height of the container, but each height requires a different spacer, which increases the number of stock components disproportionally.

[0006] A solution is known from US 4617616, involving a cylindrical container for housing the inset light fixture, which container has an intermediate cylindrical wall section having an outer diameter slightly less than the inner diameter of the remaining wall sections. By cutting the container cross to its axis at a first position in the wall section of smaller diameter and a second position in the wall section of larger diameter, and removing the interposed portion of the container, upper and lower container members are obtained which can be telescoped one into the other. As a result, the overall height of the container and the rotational position of one portion relative to the other can be adjusted independently.

[0007] Somewhat analogously, JP 03-084108 describes a container for housing an inset light fixture having an upper cylindrical member which can be telescoped inside a lower cylindrical member of larger diameter. The cylindrical wall section of the upper member comprises a threaded hole for a set screw. The set screw is inserted from the inside of the upper member to frictionally engage the inside wall of the lower member and fix the position of the upper member relative to the lower member.

[0008] The above solutions still suffer from a number of disadvantages. A first one is that the height positioning and rotation orientation of the upper and lower members cannot be made in the factory or workshop and must necessarily be made on the construction site. The set screw in JP 03- 084108 is not sufficient for providing a reliable securing force which can withstand transportation and handling of the containers. A second disadvantage is that the interface between the upper and lower members is not reliably water tight. Waterproofness is ensured only by the concrete or epoxy poured around the container in order to fix it to ground. However, over time, cracks can occur, which increase the risk of water oozing in the container through the interface. A third disadvantage is that possible ground settlements can tear the upper and lower member out of registration to one another, increasing the risk of water ingress.

[0009] It is therefore an aim of the present invention to provide containers for flush mounted inset lights which overcome the above drawbacks. Particularly, it is an aim to provide inset light containers which are easily adjustable, both in orientation of the cable entry points and in height and which are more robust, such as by having an improved ease of handling.

[0010] It is an aim of the present invention to provide inset light containers which are easily adjustable by only requiring a minimal number of components.

[0011] Another problem occurring with inset light containers of the above type is that, since threaded holes are used for securing the inset light fixture to the container, this thread can fail during various subsequent replacements of the light fixture. Typically, the threaded holes are made integrally with the container and repair can only be carried out by drilling out the threaded hole followed by threading the enlarged hole in order to bring in a new threaded insert. This all has to be done on the field, since the containers are potted in the pavement and cannot be removed. Furthermore, a failed insert can only be replaced once due to a lack of space for accepting ever increasing replacement inserts.

[0012] A way to solve the above problem is known from US 6550931 , which describes to provide removable inserts in a support flange of the container. The inserts feature a threaded hole for receiving securing bolts holding the light fixture on the support flange. The inserts are cylindrical with longitudinal ridges radially projecting from the exterior wall to frictionally engage the interior wall surface of through-holes provided in the support flange to prevent rotation during bolt fastening.

[0013] However, the longitudinal ridges are small and after repeated replacement of the light fixtures, the exterior wall of the insert and/or the interior wall of the flange hole become easily damaged so that insert rotation cannot be prevented. This can only be solved by removing the insert, drilling a new larger hole and using a larger insert. Another problem of inserts of the above type is that they are not leak-tight.

[0014] It is therefore an aim of the invention to provide improved inserts for securing a light fixture to a container. It is an aim of the invention to provide such inserts, which are robust with regard to insert rotation during fastening of the bolts, and which are easily replaceable.

[0015] It is an aim of the present invention to provide such inserts which provide improved water-tightness.

[0016] According to a first aspect of the invention, there is provided an inset light container as set out in the appended claims. Inset light containers according to the invention are modular and comprise a base pot and a top ring.

The top ring is arranged to be secured to the base pot in a plurality of angular orientations relative to the base pot.

[0017] The top ring's under side and the base pot's upper side are formed as a cooperating combination of a flangeless sleeve and a seat adapted for mating abutment against the flangeless sleeve.

[0018] Therefore, securing the top ring and the base pot in the above plurality of angular orientations does not change the height of the container. By so doing, an azimuth correction can be carried out by adjusting the relative orientation between the base pot, which comprises cable entry provisions and the top ring (comprising the azimuth markers) without requiring height adjustment.

[0019] That part of the seat adapted to receive the flangeless sleeve has such a width and the sleeve has such a thickness, that even after the sleeve is machined to reduce its height, the ability of assembling the top ring on the base pot by abutment of the flangeless sleeve against the seat is preserved.

Therefore, the height of the container can be adjusted by simple machining the sleeve and hence removing some material and reducing sleeve height substantially uniformly along the perimeter. Thereby, the ability of assembling the top ring on the base pot is preserved, and there is no need to use additional spacers or other components. [0020] According to the present aspect of the invention, the base pot and the top ring each comprise corresponding means for securing the top ring to the base pot. According to an aspect of the invention, such means are in the form of fastening holes, regularly distributed over a plurality of angular positions along the perimeters of the base pot and the top ring. The fastening holes accept threaded fasteners which connect the corresponding fastening holes and thereby secure the top ring to the base pot in the plurality of angular orientations relative to the base pot. The fastening holes are oriented for allowing securing the top ring to the base pot even after the sleeve is machined to reduce its height. The fastening holes are advantageously aligned substantially vertically.

[0021] The corresponding fastening holes, in combination with the fasteners, provide a tight securing between the top ring and the base pot and allow for assembling the container with the desired height and rotational position according to plan in the factory or workshop. Once assembled, the container can be safely handled and transported without any risk that there is a loss in registration in height or in rotational position between the azimuth markers and the cable entry provisions.

[0022] An additional advantage is that due to the fastening of the top ring and the base pot through the fastening holes, there is no need to have a telescopic wall section such as in US 4617616 and JP 03-084108 in order to provide sufficient structural strength to the container. Both strength (e.g. for transportation) and height or rotational adjustment can be obtained with the fastening holes. As a result, a container is obtained which can have a reduced height compared to prior art containers without loss of functionality. Indeed, the minimal wall height of containers according to the invention corresponds to the height of lateral cable entry provisions and the height of the light fixture which will be mounted in the top ring. No additional wall height for a telescopic section is required, such that containers according to the invention can be produced which are shallower than prior art containers. This enables for adapting the container height to evolution in LED lighting fixtures which are becoming smaller and of reduced height. In prior art containers, the height cannot be reduced, since otherwise, the telescopic wall section would block the cable entry provisions (cable feed throughs).

[0023] Therefore, the co-operating combination of flangeless sleeve and seat advantageously are not telescopic. Hence, force transmission between the flangeless sleeve and the seat, such as due to a moment of force acting about a horizontal axis, is advantageously (substantially) oriented along a vertical axis. Advantageously, no (substantial) force is transmitted between the flangeless sleeve and the seat in a direction normal to the wall of the sleeve.

[0024] Another advantage over prior art containers is that mounting of the container is eased, in particular when an airfield plan is available. In the containers of US 4617616 and JP 03-084108 one would first need to install the lower member and aligning it with the cable positions and thereafter install the upper member and align it with the azimuth and at the correct height. An alignment hence needs to be carried out twice, viz. for the lower member and for the upper member, and despite the availability of detailed airfield plans. Conversely, the fastening holes according to the present aspect of the invention allow a reliable adjustment between the base pot and the top ring to be made prior to installation into ground. During installation, the entire container is aligned by aligning the top ring only. There is no need to align the base pot as well as this has been done during assembly of the container. It follows that the time for installing the container on the construction site is reduced.

[0025] Yet another advantage, is that due to the fastening holes and the fasteners that can be used, it becomes possible to provide a sealant or adhesive between the top ring and base pot, making the interface watertight, at the time the container is assembled in factory or at the workshop, hence prior to transportation to the construction site (airfield). Since the container can be safely transported, there is no risk that the sealant or adhesive would become damaged. Since the sealant or adhesive can be applied in factory or in the workshop under much more favourable conditions, containers according to the invention provide for improved water tightness and reduced installation times.

[0026] Advantageously, the fastening holes are provided at an outer perimeter of the top ring and the base pot. As the fastening holes and hence the fasteners are external, they provide improved anchoring of the container in the epoxy or concrete casting.

[0027] According to a second aspect of the invention, there is provided a kit of a container and one or more inserts. The container is arranged to be potted in a pavement of e.g. an airport air traffic lane, such as a runway or a taxiway, and is provided with a support flange configured for supporting and securing a light fixture. The light fixture is advantageously, though not necessarily, a flush-mounted inset light fixture and the container is advantageously configured therefor (i.e. it is an inset light container).

[0028] According to the second aspect of the invention, the support flange is provided with through-holes comprising or consisting of downwards diverging conical portions. The one or more inserts comprise downwards diverging conical parts, advantageously provided at an upper end of the insert. The inserts are configured for insertion in the through-holes such that the conical parts fittingly engage the conical portions. The inserts' conical parts are provided with threaded blind holes accepting securing bolts for the light fixtures.

[0029] The conical parts and portions, and the blind holes make the insert and the interface between insert and support flange water tight.

[0030] The insert advantageously further comprises a shoulder arranged below the conical part and being of a non-circular and preferably polygonal cross section. The shoulder is advantageously arranged to cooperate with a recess in the flange, the recess advantageously forming a lower end of the through hole and advantageously being of cross section corresponding to the shoulder in order to prevent rotation of the insert during fastening of a bolt therein.

[0031] Further advantages of the above aspects of the invention are described in the appended dependent claims.

[0032] Aspects of the invention will now be described in more detail with reference to the appended drawings, wherein:

[0033] Figure 1 represents an exploded perspective view of a container according to the invention;

[0034] Figure 2 represents a perspective view of the top ring of

Figure 1 's container, turned upside down; [0035] Figure 3 represents a partial radial cross section of base pot and top ring with a detail of the seat and the flangeless sleeve;

[0036] Figure 4 represents a cut-out of an upper part of the top ring representing the support flange with through-hole and corresponding insert for securing the light fixture according to the invention;

[0037] Figure 5 represents a cross section of the insert of figure 4 in greater detail;

[0038] Figure 6 represents an exploded perspective view of the container of figure 1 and a flush-mounted inset light fixture.

[0039] Referring to figure 1 , a container 10 for a flush-mounted inset light comprises a base pot 1 1 onto which a top ring 12 can be mounted. The container 10 is advantageously used for receiving an inset light 60 as shown in exploded view in figure 6. Returning to figure 1 , the base pot 1 1 forms the bottom section of the container 10. It is therefore provided with an advantageously substantially flat bottom 1 10 which is surrounded by an upright wall 1 1 1 . The bottom 1 10 can be circular, or of polygonal shape.

[0040] Inset light containers according to the invention can have different sizes to accept inset light fixtures 60 of different diameters, such as 8 inch, or 12 inch.

[0041] Base pot's bottom 1 10 and upright wall 1 1 1 define a central axis 101 , which is substantially parallel to the wall 1 1 1 and substantially perpendicular to the bottom 1 10. When bottom 1 10 is of circular or (regular) polygonal shape, axis 101 can be seen as an axis of symmetry.

[0042] At a plurality of angular positions (about axis 101 ) circumferentially along the upright wall 1 1 1 , possibly identical cable entry provisions 1 12 are provided. Cable entry provisions 1 12 may take the form of possibly circular frangible recesses 1 13. Once the location of cable entry is determined, the corresponding recess 1 13 can be punched in order to create an opening to the inside of the container 10. As can be seen from figure 1 , base pot 1 1 comprises four such cable entry provisions 1 12, regularly distributed at 90° intervals. More or less cable entry provisions 1 12 can be provided as desired. However, since it is not feasible to provide a large number of cable entry provisions, as this would substantially weaken the container and make it more difficult to manufacture, the present invention provides for angular adjustment between the base pot and the top ring (about axis 101 ) as will be described further below.

[0043] It is also possible to provide cable entry provisions in the bottom 1 10 in addition to, or alternatively to the wall 1 1 1 .

[0044] Around the outer perimeter of the upright wall 1 1 1 , possibly threaded fastening holes 1 14, by which the base pot 1 1 can be fastened to the top ring 12, are provided. In figure 1 's base pot 1 1 , eight fastening holes 1 14 are provided, regularly distributed along the wall 1 1 1 (at 45° intervals).

[0045] On top of the upright wall 1 1 1 a flange-like collar 1 15, which forms a seat for the top ring 12, is provided. Reinforcement ribs 1 16 are advantageously provided to increase mechanical strength between the wall 1 1 1 and the collar 1 15.

[0046] The top ring 12 has a tubular shape and can be divided into an upper part 121 and an under part 122. The upper part 121 is provided with a flange 123 which forms a support for an inset light or light fixture. Referring to figure 2, showing the top ring 12 of Fig. 1 upside down, bracing supports 124 reinforce the flange 123 and abut against the upper part 121 .

[0047] According to an aspect of the invention, the under part 122, which can be integrally formed with the upper part 121 , is formed as a flangeless sleeve, which can have the shape of a hollow cylinder or a hollow right prism with regular polygonal base. The bottom of sleeve 122 is arranged for mating with the seat formed by collar 1 15, such that along the perimeter of the container 10, there is advantageously continuous contact between the top ring 12 and the base pot 1 1 .

[0048] Advantageously, and referring to figure 3 representing the collar 1 15 and the sleeve 122 in greater detail, sleeve 122 has a substantially flat (i.e. horizontal) under side 125 which mates with a substantially flat upper face 1 17 of collar 1 15. The collar 1 15 may be provided with projecting rims 1 18, 1 19 along either one or both the inner and outer perimeter of the upper face 1 17 for easing assembly of the base pot 1 1 and the top ring 12. A snug fitting of the sleeve 122 against either one projecting rims 1 18 and 1 19 is not required. [0049] Advantageously, only the flat faces 1 17 and 125 of the base pot 1 1 , respectively top ring 12 are configured for entering into abutment against each other during use of the container 10. The projecting rims 1 18 and 1 19 advantageously only serve a purpose of facilitating assembly and improving sealant or adhesive action. As a result, force between the base pot 1 1 and the top ring 12 is advantageously transmitted only along directions perpendicular to the flat faces 1 17 and 125.

[0050] Possibly, a sealant or an adhesive can be applied between the mating faces 1 17 and 125 for securing base pot 1 1 and top ring 12 to each other prior to installation, such as in the factory or the workshop where the container 10 is assembled, or at least prior to casting the epoxy resin.

[0051] Mating faces 1 17 and 125 of other shape than flat may be provided, even though, as will be explained below, this may make height adjustment of the container somewhat more difficult.

[0052] According to an aspect of the invention, container 10 is adjustable in height, not by adding spacers or the like such as in the prior art, but by removing material, i.e. by reducing the height of the top ring 12 as follows. Flangeless sleeve 122 of the top ring 12 has a substantially constant or weakly evolving wall thickness throughout its height. This ensures that, when the container height needs to be adjusted, it suffices to remove a bit of material from sleeve 122 (uniformly along the perimeter) in order to reduce its height. Material removal can easily be performed by machining, such as turning or sawing. By so doing, a new face 125 is created at the under side of sleeve 122, which mates with the upper face 1 17 of collar 1 15. Height adjustment can either be performed in factory, such as once the installation plan is ready and the dimensions are known, or on the field, during installation.

[0053] The wall thickness of the sleeve 122 (throughout the height) need not be constant. Sleeve 122 can e.g. have conical inner and/or outer surfaces. Referring to figure 3, the sleeve 122 has a wall thickness T1 at the lower end (the end configured for abutment against face 1 17 of collar 1 15). The wall thickness of the sleeve 122 increases (slightly) towards the upper part 121 , such that it has a (largest) wall thickness T2 at the upper end of the sleeve 122 with T2 larger than T1 . In this case, it suffices to make the upper face 1 17 of collar 1 15 of a width W larger than or equal to T2. This ensures that the top ring mates with the base pot even after height adjustment.

[0054] As a result, a height-adjustable container is provided, which requires a minimal number of components. This avoids large stocks and reduces lead times, since containers in a large number of heights can be provided within a limited time frame. This is advantageous not only for the manufacturer, but also for the airport operators, which only need to keep a limited number of spare parts in stock.

[0055] It will be convenient to note that the combination of co- operating collar 1 15 and sleeve 122 can be inverted between the base pot 1 1 and the top ring 12, in that the collar 1 15 can be formed at the underside of the top ring 12 whereas the sleeve 122 can be provided on top of the base pot 1 1 , without any loss of the advantages mentioned above.

[0056] To cope with cases in which a container 10 with larger height than the total maximal height of the assembly of base pot 1 1 and top ring 12 is required, it will be advantageous to form the under face of the upright wall 1 1 1 and/or of the periphery of the base pot's bottom 1 10 such that it mates with the upper (seating) face 1 17 of collar 1 15. In other words, it is advantageous to make identical base pots 1 1 superposable or stackable. By removing the bottom 1 10 of the middle base pots 1 1 , a container can be assembled by stacking two or more base pots 1 1 , with on top one top ring 12.

[0057] Referring to figure 3, the outer diameter D1 of the base pot's bottom 1 10 advantageously fits within the outer diameter D2 of the upper face 1 17 (corresponding to the inner diameter of the projecting rim 1 18). A groove 108 is advantageously provided at the underside of the bottom 1 10 along the perimeter and spaced inwards from it, for accepting the projecting rim 1 19 of another (identical) base pot 1 1 when the two are stacked on top of each other. By so doing, a mating abutment of bottom 1 10 and top (collar 1 15) is obtained. The groove 108 can be filled with a water repellent adhesive when stacking two base pots.

[0058] Part of bottom 1 10 can be made removable, such as by machining, or by providing lines of weakness for facilitating removal of a bottom part by punching. Referring to figure 1 , bottom 1 10 is provided with a circular frangible recess or groove 109 for this purpose.

[0059] As a result, a modular container is provided, adjustable to almost every possible height, and made up of only two different components, viz. the base pot 1 1 and the top ring 12.

[0060] Alternatively, an intermediate ring can be provided (not shown), which is stackable between the base pot 1 1 and the top ring 12. Such an intermediate ring has end faces which are respectively configured to mate with the upper face 1 17 of the base pot 1 1 and the under face 125 of the sleeve 122 (top ring 12). The intermediate ring can be secured to both the base pot 1 1 and the top ring 12 in the same way as the top ring is secured to the base pot and which will be described further below. In such case, the modular container is made up of only three different components.

[0061] In order to ease machining, it will be convenient to make the top ring 12, and optionally the base pot as well, of an aluminium alloy. The aluminium alloy is advantageously cast in a mould by high pressure injection, which allows for obtaining parts with accurate details without requiring post- machining. Materials other than aluminium alloys, such as injection mouldable polymeric materials, or thermoplastic materials can be used as well, in particular for the base pot 1 1 .

[0062] Referring back to figure 1 , markers 13 are provided on, and possibly integrally formed with, the top ring 12 for aligning the container 10 with the centre line or axis of the runway or taxiway. Markers 13 are hence used for azimuth correction. In addition, the upper part 121 of the top ring 12 is advantageously made such that the inset light can be mounted in the top ring 12 (or in the container 10) in one or a limited number of possible orientations relative to the marker 13. This may be obtained by providing corresponding projections and recesses at determined locations as is known in the art. This ensures that once the container is aligned correctly, mounting of the inset light becomes straight forward without any possibility of erroneous orientation.

[0063] Containers according to an aspect of the invention allow for orienting the cable entry provisions 1 12 according to a plurality of angular positions (about axis 101 ) relative to the markers 13. To this end, the top ring 12 is provided with an external flange 126 along its perimeter, possibly but not necessarily interposed between the upper part 121 and the under part (sleeve) 122. Possibly threaded fastening holes 127 are provided through the flange 126 at a plurality of advantageously regularly distributed angular positions (about axis 101 ). In the top ring 12 of figures 1 and 2, four such fastening holes are provided at 90° intervals. It can be seen that both fastening holes 1 14 and 127 are aligned with the vertical axis 101 of the container 10. The fastening holes 127 of the top ring 12 are arranged to co-operate with the fastening holes 1 14 of the base pot 1 1 in order to secure base pot 1 1 and top ring 12 to each other. To this end, both types of fastening holes may be arranged for accepting a same type of threaded fastener, such as bolts, bolts and nuts, or threaded rod with nuts at both ends. Therefore, either one of the fastening holes 1 14 and 127 may be threaded with the other one being a non-threaded through-hole arranged for abutment of the bolt head or a nut.

[0064] It will be convenient to note that the fastening holes can have other shape than holes 1 14 and 127 depicted in the figures. They can e.g. be holes having an open perimeter (e.g. recesses or grooves in the wall of the top ring or base pot, allowing securing a threaded fastener thereto), or holes accepting an eye bolt and corresponding nut. In the latter case, the loop of the eye bolt turns through one hole (on an axis at the perimeter of the hole), whereas the nut serves for securing the eye bolt in the corresponding hole in the other part of top ring and base pot.

[0065] The number of fastening holes 1 14 on the base pot 1 1 is advantageously double or a multiple of the number of fastening holes 127 on the top ring 12. As a result, the angular interval (along the perimeter, about axis 101 ) between the fastening holes 127 of the top ring 12 is a multiple of the angular interval between the fastening holes 1 14 of the base pot 1 1 . This allows for mounting and securing the top ring 12 in a plurality of angular orientations relative to the base pot 1 1 , so that the orientation of the cable entry provisions 1 12 is adjustable relative to the orientation of the markers 13. In the example of figure 1 , cable entry provisions 1 12 can be oriented at 45° intervals relative to the markers. [0066] Having a multiple number of fastening holes on one member

(top ring 12 or base pot 1 1 ) with regard to the other member also allows to stack multiple base pots on one another, or to stack the intermediate ring between the base pot and the top ring. The intermediate ring hence would have a sufficient number of fastening holes, with some fastening holes to be used for securing it to the top ring, and other ones to be used for securing it to the base pot.

[0067] Making the orientation of the cable entry provisions 1 12 adjustable is advantageous, since it allows for more flexibility in drawing the cable conduits and therefore economizing cable lengths considerably.

[0068] It will be convenient to note that other ways of securing base pot 1 1 and top ring 12 in a plurality of relative angular orientations are possible, such as by clasping. Instead of securing at discrete angular orientations, some means, such as clasps, can allow for securing at any continuous angular position. However, threaded fasteners are superior to clasps. The latter have an increased risk that they become loose. Also, securing the top ring to the base pot at any continuous angular orientation may not be desirable, since the rotational registration cannot be maintained stable in all circumstances during transportation and handling.

[0069] According to another aspect of the invention, an improved assembly is provided for fastening or securing the inset light fixture on the top ring, or more generally, in a corresponding container. Referring to figure 1 , in the inset light fixture supporting flange 123 through-holes 14 are provided, of which figure 4 represents a radial cross section in greater detail. Through-holes 14 comprise conical upper portions 141 , with circumferentially continuously extending, downwards diverging conical walls. The flange advantageously further comprises a recess or pocket 142 in a lower part of through-hole 14. Pocket 142 has a size larger than the base of the conical portion and is advantageously concentric with the conical portion.

[0070] An insert 15 of shape corresponding to the through-hole 14 is provided for insertion therein. Insert 15, which is represented in cross section in figures 4 and 5, comprises a part 151 having a (frusto-)conical outer surface of size corresponding to conical portion 141 of through-hole 14. Conical part 151 hence has a circumferentially continuously extending, downwards diverging conical wall.

[0071] Advantageously, insert 15 further comprises one or more shoulders 152 of size larger than the base of conical part 151 . Shoulder 152 is advantageously formed as a prismatic element having a (horizontal, i.e. in a plane perpendicular to the axis 157 of the conical part 151 ) cross sectional shape other than circular, such as polygonal. Shoulder 152 is advantageously concentric with the axis 157 of conical part 151 . The cross section of shoulder 152 can be constant throughout the shoulder height.

[0072] Insert 15 is arranged for being inserted from the underside of the flange 123 into through-hole 14 and it will therefore become evident that shoulder 152 is arranged below the conical part 151 , at the diverging end 158 of conical part 151 . Conical portion 141 of through-hole 14 then accepts conical part 151 of the insert 15 and pocket 142 accepts part of shoulder 152.

[0073] Rubber grommets 16 are advantageously secured (e.g. by screws 161 ) to the under face of flange 123, at either side of through-hole 14, and such that insert 15 can snugly fit in between (at the level of shoulder 152). When insert 15 is inserted into through-hole 14, it is frictionally held by rubber grommets 16 to prevent that the insert 15 would fall out. It may hence be seen that it is advantageous to have insert 15 (shoulder 152) project below through- hole 14 and flange 123 once inserted (i.e. to have it project out of pocket 142). This means that, advantageously, the height of shoulder 152 is larger than the depth of pocket 142.

[0074] Insert 15 further comprises an advantageously blind threaded hole 153 configured for accepting a screw 61 for fastening the inset light fixture 60 (see figure 6) once the insert 15 has been inserted in through- hole 14. Threaded hole 153 is hence open towards the top and advantageously closed at the bottom. Hole 153 is therefore provided in the conical part 151 and is concentric with the cone axis 157.

[0075] Hence, in order to secure an inset light fixture in a container, inserts 15 are inserted from below into the through-holes 14 provided in the supporting flange 123 of a container. Inserts 15 are frictionally held in place e.g. by the rubber grommets 16. Referring to figure 6, the inset light fixture 60 can now be placed on the supporting flange 123 and can be secured to the container by screws 61 or bolts that are fastened into inserts 15. By fastening the screw 61 , conical part 151 of the insert will be tightened into the conical hole 141 . This will provide for automatic centring of insert 15 and the screw in through-hole 14.

[0076] Shoulder 152 provides a mechanical limit to the screw tightening, so as to prevent that the insert would be torn out of the through-hole 14. Hence in the initial insertion position of insert 15 into through-hole 14, upper face 154 of shoulder 152 advantageously does not touch any under face of the flange, so as to permit a small upward motion of the insert 15 further into the through-hole 14 during fastening of the inset light fixture 60.

[0077] When shoulder 152 and pocket 142 have cross sections of corresponding shape other than circular, they can inhibit rotation of insert 15 about its axis during fastening of the screws into threaded holes 153. Referring to figure 2, it is seen that shoulder 152 can be formed of a right prism with rectangular or other polygonal (horizontal) base.

[0078] Inserts 15 and corresponding through-holes 14 according to the present aspect of the invention not only allow for securely fastening inset light fixtures in a container, but they are replaceable as well, such as in case of failure of the thread in hole 153 during e.g. replacement of a light fixture. It suffices to punch the failed insert 15 (downwards) out of the through-hole 14 and to replace it with a new one. No additional machining will be required.

[0079] An additional advantage of present inserts 15, is that they provide improved water-tightness, which is an important aspect, since any water oozed in the container may damage electric (cable entries) or electronic parts and may cause short circuits causing undesired failure of air traffic lights. Water-tightness is obtained through a number of provisions. Firstly, the conical faces of insert 15 and through-hole 14 provide for a leak-tight interface between the container (flange 123) and the insert. Secondly, when the threaded hole 153 is made as a blind hole, closed at the bottom, it is prevented that water oozes into the container via the thread.

[0080] As an additional measure, a gasket such as an O-ring 156 can be provided at the base of the conical part 151 of insert 15. A groove 155 can be provided circumferentially around the insert (the conical part 151 ) for housing the O-ring 156. Alternatively, or in addition thereto, a waterproof lubricant can be provided on the external face of conical part 151 in order to provide increased leak-tightness of the interface between through-hole 14 and insert 15.

[0081] As a yet additional measure, support flange 123 can be provided with a groove 128 circumferentially around the inner perimeter for housing an O-ring in order to make the interface between light fixture 60 and support flange 123 leak tight towards the container.

[0082] It will be convenient to note that the application of the light fixture fastening assembly with inserts as described above is not limited to modular inset light containers according to the first aspect of the invention, but is generally applicable to any inset light container, in particular those for use in airport air traffic lanes.

[0083] It will also be convenient to note that the application of the containers and assemblies as described above in relation to both the first and the second aspects of the invention is not restricted to airfields, but can be extended to other traffic lanes, such as for road traffic.