This invention relates to drop-down access panels for example for use in ceilings and other overhead locations, and is particularly suitable for use in conjunction with suspended ceilings.

A suspended ceiling consists of an arrangement of tiles or panels hung from a supporting framework. For aesthetic reasons it is preferable that any movable access panels should be of the same appearance as the remainder of the ceiling when viewed from below.

A problem with movable ceiling access panels is that unless special provisions are made to prevent clashing of the panels and the adjacent ceiling parts on opening, the edges of the panel and/or adjacent ceiling parts can become damaged and unsightly. Panel guide arrangements to prevent such damage are known, but are generally relatively complex and expensive.

From Patent Specification GB 2209558 there is known a hinge for mounting between the rear face of a ceiling access panel and an adjacent fixed support. The hinge is of generally Z-shaped form, having a substantially planar leaf attachable to the panel rear face, a similar leaf attachable to the fixed support and an intermediate leaf connected between the other leaves. This arrangement is relatively expensive to produce and awkward to install, particularly in the case of pressed metal ceiling panels, where it is difficult to conceal the fasteners used to attach the panel to the adjacent hinge leaf.

The present invention provides a simple and inexpensive means for prevention of edge damage, in the form of a coupling for attachment between a panel support structure and

a drop-down access panel having an upstanding mounting flange, the coupling including a link member having a hinged connection for attachment to the mounting flange and a further hinged connection for attachment to the support structure and spaced from the panel connection, characterised in that the mounting flange connection comprises a hinge pin extending from the flange in use, and upon which the link member is journalled. Thus, once one edge of the access panel has been unfastened and eased downwardly clear of the surrounding ceiling or other structure, the pair of hinged connections enable the access panel to move sideways to prevent clashing of the panel's opposite edge and the adjacent structure edge.

Providing the hinged connection between the mounting flange and the link member ensures that the coupling is not visible from below, even when used with pressed metal panels. Conveniently the mounting flange may comprise an upstanding edge flange of such a panel, or it could egually well comprise a panel edge frame.

The link member may be formed from flexible material such as cord or flexible tape. However, it preferably comprises a substantially rigid strut having the mounting flange connection at one end and the support structure connection at the other end. The coupling may comprise a pair of such struts, disposed in parallel on either side of the panel. Advantageously, the support structure connection is formed in similar manner to the mounting flange connection.

The strut is preferably cranked so that its length can be adjusted by bending the centre section using a pair of pliers. This provides a simple means for ^' levelling the closed access panel with respect to the ceiling or other surrounding surface.

Preferably the coupling lies towards an end of the access panel with the hinged connections lying along a line which slopes upwardly away from that end, towards the other end of the panel, whereby the panel end nearest the coupling will tend to fall away from any surrounding structure upon release of the panel.

The panel will normally be held in position at its other end by any suitable releasable fastening means, such as the ⁿ _T ^ιι j-, _{ar anc} j flange fastenings usually used to support ceiling panels, quarter turn or "budget ¹¹ locks, or touch latches (i.e. latches of known kind releasable by upward pressure on the panel) such as those sold under the trade mark "AUTOLOCK". The length of the coupling and the position of its attachment to the supporting structure will normally be chosen so that in its fastened condition the panel lies flush with the remainder of the ceiling or other surface in which it is mounted.

The access panel may be formed from a standard metal tray ceiling panel, which will therefore match the surrounding ceiling panels when viewed from below. The metal tray panel used to form the access panel may be stiffened by a strut attached between opposite edge flanges. A number of metal tray panels may be fastened together side-by-side to form a larger access panel, stiffened by a single crosswise strut. To minimise the risk of the access panel edges clashing with the surrounding panel edges, the flanges of the metal tray panel from which it is formed can be bent to a rounded profile, for example by pressing or hammer forming.

These and other preferred features of the invention will be apparent from the following description made by way of example and with reference to the drawings in which:-

Fig. 1 is a perspective view from above, with certain parts broken away or omitted for clarity, showing an access

panel mounted in a suspended ceiling using a coupling forming one embodiment of the invention and fastened by touch latches;

Fig. 2 is a cross-section of the panel of Fig. 1, viewed in the direction of arrow A;

Fig. 3 shows details of one of the touch latches, viewed in the direction of arrow B in Fig. l;

Fig. 4 is a cross sectional view similar to Fig. 2 but showing an access panel fastened by a pair of budget locks;

Fig. 5 is a view similar to Fig. 3, showing details of one of the budget locks;

Fig. 6 is a view taken on arrow C in Fig. 1, showing a link member and its mountings;

Fig. 7 is an exploded perspective view of a link member and its mountings; and

Fig. 8 is a view taken on arrow A in Fig. 1 showing a link member and the adjacent access panel end half-opened.

Referring to Fig. 1 there is shown a suspended ceiling 10 comprising a number of panel positions P whose boundaries are indicated schematically by lines 12. As is conventional, the panels are suspended at these positions from "T"-bars 14, 15 (shown broken away). A drop-down access panel 16 made by modifying a standard metal tray panel has a pair of upstanding parallel edge flanges 18, 20 cross- connected by a stiffening channel 24. As shown, the channel 24 lies below the level of the upper ^' edges of the flanges 18, 20, although other arrangements are possible. For example, where a larger access opening occupying several panel positions is required, the channel 24 may be arranged

to run above and stiffen several panels whose adjacent edges are connected together.

On either side of the access opening parallel to the flanges 18, 20, a pair of supporting beams 26 are provided, fixed to the "T"-bars 14, 15. (Only one beam 26 is shown in Fig. 1, the beam parallel to flange 20 being omitted for clarity. ) One end 28 of the panel 16 is suspended from the beams 26 by a coupling comprising a pair of cranked struts 30. The other end of the panel 16 is held closed by a pair of touch latches 32 (one only partly shown) attached to the beams 26. The beams 26 also serve as guard rails on either side of the access opening, preventing excessive loading of the ceiling by maintenance personnel. Many other forms of latch will be suitable, but a touch latch is preferred as it does not show when the panel is closed and viewed from below. Where the panel will not be opened repeatedly, it may be sufficient to use an upstanding edge flange of the conventional kind found in metal tray panels to engage with "T"-bar 15, next to the edge flange supporting the adjacent fixed ceiling panel at position PI. Such flanges are referenced 34 in Figs. 1-6.

Fig. 2 shows that in the closed position the underside of the access panel 16 is supported level with the adjacent fixed panels 36, 38. In this position, the struts 30 lie at an angle with their pivots 40, 42 lying along a line which slopes upwardly and away from panel end 28. A safety cord or chain (not shown) is attached to eye 11 screwed to T-bar 14 and has a spring hook (not shown) at its other end releasably engageable with another eye 13 screwed to stiffening channel 24.

Fig. 3 shows in more detail the touch latch 32 whose body part 31 housing the latch mechanism is screwed to supporting beam 26 via its base plate 33 and whose latch hook 35 is screwed to the stiffening channel 24 via its base plate

37, for releasable engagement within the body part 31. Fig. 3 also shows that the stiffening channel 24 is fastened to the access panel edge flange 18 by pop rivets 19. To allow the rivet heads to clear the adjacent fixed panel flange 34, flange 18 is recessed at 19 by pressing or hammer forming. The other end of channel 24 is similarly fastened to the flange 20.

The arrangement shown in Figs. 4 and 5 is similar to that of Figs. 2 and 3, except that budget locks 39 are used in place of the touch latches 32. The stiffening channel 24 is attached between the access panel edge flanges 18, 20 in a slightly higher position and closer to the adjacent panel edge compared to Figs. 2 and 3, to allow the tongue 41 of the budget lock 39 to engage above the T-bar 14 in the closed position. The budget lock 39 is bolted to the top surface of the stiffening channel 24.

The panel end flanges 27, 29 are inwardly bent (for example by pressing or hammer forming) and the upper corners of the side flanges 18, 20 are trimmed off to provide rounded front and rear edge profiles on the access panel which will not clash with the adjacent edges of fixed panels 36, 38.

Figs. 6 and 7 show that each link 30 is cranked at 46 so that it may be bent about lines 48, 50 using a pair of pliers to adjust the level of the access panel relative to the surrounding ceiling. The pivots 40, 42 may conveniently be formed by 3mm brass bushes 52 mounted between pairs of washers 54 on machine screws 56, 58 secured to the panel flanges 18, 20 and the supporting beams 26 respectively by nuts 60. The strut 30 has holes 62 at either end by which it is journalled on the bushes 52, and is of narrower width than the bushes 30 so that it can pivot freely between the washers 54. Recesses 44 are formed in the flanges 18, 20 to accommodate the heads of the machine screws 56 and ensure that they do not clash with the edges of the adjacent fixed

panels .

In an alternative embodiment which permits the ready removal of the access panel 16 if desired, the pivots 40 are formed by a rod running transversely of the entire panel 16 and having outwardly spring-loaded ends journalled in opposed bearing cups fixed to the beams 26.

Fig. 8 shows the access panel 16 opened so that the struts 30 have dropped to occupy a substantially vertical orientation. This causes the edge of the panel 16 to fall away from the edge of the adjacent fixed panel 36.