GB2228954A - Ceiling panels - Google Patents

Abstract

A panel for use in a suspended ceiling comprises a primary plate 11 which defines an insulation receiving tray. Insulating material 12 is disposed in the tray and retained therein by a backing plate 13. The backing plate 13 is held in position by substantially vertical members (e.g. the longitudinal edge portions 16 shown or separate flange members) secured to upturned edge portions 14 on the primary plate 11. The backing plate 13 also provides rigidity to the panel. The tray may be perforated to assist sound insulation. Further insulation material may overlie the backing plate. <IMAGE>

Description

IMPROVEMENTS IN PANELS FOR CEILINGS The present invention relates to a panel which can be used for example in a suspended ceiling to provide thermal and acoustic insulation.

When for example an office, laboratory or other workspace provided with a suspended ceiling is required to be partitioned into smaller units by way of partition walls it is common practice to build the partitioning walls only up to the height of the suspended ceiling in order to reduce costs and often also to provide a greater degree of choice in the resiting of the partitioning walls.

It is usually desirable that conversations in one office unit should not readily be overheard in adjacent office units, and partitioning walls are usually designed to provide sound attenuation so that privacy between offices can be maintained. However, no matter how good the degree of sound attenuation provided by the partitioning walls a path along which sound can travel exists through the suspended ceiling from one office unit to the next, and in order to provide sound attenuation in this path the ceiling also should be acoustically corrected.

Moreover, most modern offices are air conditioned, with ducting in the void above the suspended ceiling providing the conditioned air and the space above the ceiling i.e. the ceiling void being used as a negative plenum return air path to pull the air back to the plant room for re-circulation in a conditioned mode.

To obtain optimum performance of the air conditioning system the suspended ceiling should provide an effective air-tight barrier between the office space below and the void space above the ceiling with the return air being pulled back in a controlled manner through return air grilles with damper controls or through perforated backs of luminaire housings.

If there are weak air paths through the holes of a perforated metal ceiling this will in time result in pattern staining on the surface of the metal tile.

Due to the configuration of mechanical items in the space above the ceiling a certain amount of noise (sound) may be generated in the void. It is necessary sometimes to have a sound absorption plane on the back of the metal ceiling tile to provide this acoustic correction. If a flat metal backing plate is used (flat metal being an excellent medium for preventing the passage of sound from the offices below the ceiling) this surface reverberates sound generated in the void and does not absorb it.

In hitherto known arrangements, namely those of our so-called System 320 and System 330 ceiling panelling systems, simple lay-in and hang-on ceiling panels press formed from electro-galvanised (Zintec) mild steel and factory finished with polyester powder paint to a smooth or textured finish as required are supported from exposed linear grid sections to form a flush ceiling wherein the lower faces of the panels are aligned with the grid sections in the same horizontal plane. The panels are simply hung-on or laid-into the pre-assembled grid and can be used alone (plain face) or, where acoustic absorption and attenuation is required, with non-combustible mineral wool insulation pads simply laid into the backs of perforated panels.One such arrangement is shown schematically in Figure 1 of the accompanying drawings where a main panel 1 is formed to house a layer of acoustic insulating material 2 and a backing plate 3 is placed on top of the insulating material 2 and engages behind the tabs or flanges 4 provided on the main panel 1. The backing plate 3 serves to sandwich the insulating material 2 in position, and to provide an enhanced level of sound attentuation. The lower face 5 of the main panel 1 is commonly perforated for acoustic purposes and the insulating layer, which commonly comprises a mineral wool matt, is wrapped in an encased envelope 6 in order to prevent fibre particles from falling through the perforations and in order to prevent the possibility of air flow through the panel.

Whilst the arrangement of Figure 1 provides satisfactory acoustic absorption and attentuation it is relatively difficult and therefore expensive to manufacture. The main panel 1 is commonly formed from sheet steel or other sheet metal and the number of bends that are required to form the main panel 1 and the nature of such bends increases the number of stages required for its manufacture which increases its manufacturing time and hence its cost of manufacture.

The tabs or flanges 4 in Figure 1 at the top horizontal edge of the panel are added to the panel to provide additional rigidity and length spanning (non deflection) characteristics to the panel.

The structural and acoustic performance of the panel shown in Figure 1 with its insulating material 2 is reasonably efficient. However, for ease of assembly of the panel, the backing plate 3 is normally cut to below a nominal size so that it may slide easily over the back of the insulating material and under the flanges 4. The result of this is that it is not possible to get a perfectly tight sandwich construction preventing total air leakage and sound leakage through the panel. Also, the backing plate 3 does not add to the structural integrity of the panel, being merely a flat un-rigidised piece of steel.

In order to simplify the manufacturing process, a simpler alternative arrangement is sometimes used. As shown in Figure 2 the main panel 7 does not include the tabs or flanges indicated at 4 in Figure 1 and can be manufactured in a single dedicated tool pressing operation. A layer of insulating material 8 within a foil envelope 9 may be placed in the tray defined by the main panel 7 but, this panel 7 does not have the equivalent rigidity of panel 1 Figure 1 because of the absence of an additional fold at the flange 4 in Figure 1.

As in the panel 1 shown in Figure 1 a plain metal panel could be laid loosely in the back of panel 7 to enhance the acoustic attentuation qualities of this panel, however this plain piece of metal normally .6mm thick Zintec Steel weighing approximately 5kg per square metre of surface area would cause distortion in the surface of the panel due to weak structural characteristics of the panel i.e. because of the absence from panel 7 of the return flange 4 present in panel 1 as shown in Figure 1.

An object of the present invention is to provide a ceiling panel of simple construction and having improved characteristics of air tightness, acoustic attentuation qualities and structural spanning qualities along its length that is to say a resistance to deflection along the length of a panel.

It is also an object of the invention to provide a ceiling panel which can act as a receiving frame for a laid-in acoustic absorbing medium placed in the back of the panel and to hold such medium firmly in position i.e, not loosely laid. Such a panel may subsequently be removed from the ceiling by maintenance engineers as an integral one piece panel.

The invention in one of its aspects provides a panel for use in, for example, a suspended ceiling, which panel comprises a primary plate defining an insulation receiving tray, insulating material disposed in said tray, and retaining means placed over said insulating material and held thereover by substantially vertical members secured to upturned edge portions on the primary plate thereby to retain the insulating material in position and provide rigidity to the panel.

In accordance with one exemplary embodiment of the invention as above defined the means placed over the insulating material and the substantially vertical members securing the said means to the tray are integral with each other, whereas in another exemplary embodiment they are separately formed.

In order that the invention may be better understood some embodiments will be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a sectional view through one type of known panel as already described hereinabove; Figure 2 shows a sectional view through another type of known panel as already described hereinabove; Figure 3 shows a partially cut away and sectioned perspective view of one exemplary embodiment of the present invention; Figure 4 shows a sectional view along the line 44 in Figure 3; Figure 5 shows panels of the kind shown in Figures 3 and 4 for example supported from a suspended hanger bracket; Figure 6 shows panels of the kind shown in Figures 3 and 4 for example alternatively supporting a wall partition head; Figure 7 shows another exemplary embodiment of the present invention;; Figure 8 shows a further exemplary embodiment of the present invention; and Figures 9 and 10 show an exemplary apparatus for use in the manufacture of panels according to the present invention, Figure 9 being an end elevation view and Figure 10 being a partial side elevation view.

Referring now to Figures 3 and 4, a rectangular panel generally indicated at 10 comprises a primary or face plate 11 (also known as a partition head support plate) defining a shallow tray (shown relatively deep for the purpose of illustration), a layer of insulating material 12, such as for example of mineral fibre, and a secondary or backing plate 13. The face plate 11 is preformed to define upwardly extending longitudinal edge portions 14 and flanged end portions 15. The backing plate is also preformed to define upwardly extending longitudinal edge portions 16,16a and, as can be seen from Figures 3 and 4 the respective edge portions of the facing and backing plates are dimensioned so that the respective ends 17,18 thereof are substantially in alignment when an insulating layer of suitable thickness is disposed between the two plates.The face and backing plates may be formed from any suitable sheet material but, because of its suitability 0.6 mm or 0.7 mm electrogalvanised mild steel is preferred. Similarly, the insulating layer can be formed of any suitable insulating material although mineral fibre is preferred on account of its non flammable properties and will typically be of the order of 10 to 15 mm deep. The adjoining longitudinal edge portions of the two plates are preferably secured together and can be secured together by any known method, such as for example by spot welding, pop riveting, stitching or by means of spire clips.The backing plate serves, in effect, to form an enclosed structure which contains the insulating layer 12 and provides rigidity to the panel under both tension and compression so that the panel is resistant to distortion and manipulation of the panel prior to and during installation is eased.

The face plate 11 can be plain or can, if desired, be formed to provide a visually pleasing appearance or profile. To this end the face plate may be perforated with regularly spaced holes and/or may even be contoured. Where the face plate is perforated it is advantageous to provide a thin layer of, for example, fibre glass cloth tissue between the face plate 11 and the insulating layer 12 to prevent particles and/or fibres from the insulating layer falling through the perforations in the face plate, and indeed it may be desirable to enwrap the insulating batt 12 entirely with tissue or other material to ensure that fibres or other particles cannot escape from the panel.

Turning now to Figures 5 and 6, it can be seen that the purpose of the flanged end portions 15 is to provide a means by which the panel may be suspended from a modular grid supporting arrangement to form a suspended ceiling. A hanger bracket 20 is shown suspended by a suspension rod 21 connected by suitable means to a building soffit and the flanged end portion 15 of a panel is placed over the hanger bracket 20 so as to be supported thereby. Nuts 21a on a threaded portion of the suspension rod 21 can be used to adjust the height of the hanger bracket It will be appreciated that a hanger bracket will normally be provided for each end of the panel 10 and several such panels will be placed side-by-side along the length of the hanger bracket to form the suspended ceiling. In order to ensure equal spacing between hanger brackets a distancing bar 22 may be used.A compressible gasket 23 is optionally provided on the flanged end portions 15 of the panels to reduce thermal and acoustic leakage between the panels and the hanger bracket and provide a recessed edge feature therebetween if required. A "C" profile finishing member 24 can be clipped over the lower face of the hanger bracket 24 to provide a finish matching the finish on the lower faces of the panels, if required.

Where the ceiling is to be installed in conjunction with partitioned walls, a partition head support bracket 25 can be used as shown in Figure 6 at the top of the partition 26 to provide support for the panels 10. Again, compressible gaskets can be used between the end 15 of the panel and the head support bracket 25.

Figure 7 shows another embodiment of the panel wherein a plasterboard 27 is placed over the insulating material 12 and separate flange members 28 are secured to the edge portions 14 of the face plate 11 by any convenient means as aforementioned to hold the plasterboard in position. The plasterboard 27 provides adequate acoustic and thermal insulation and, if suitably dimensioned, will provide rigidity to the panel under both tension and compression to prevent the panel from sagging downwards when installed. This arrangement is similar in some respects to that of Figure 1 but is more easily manufactured.

In another embodiment shown in Figure 8, the panel is provided with another layer of insulating material 29 in addition to the insulating layer 12 sandwiched between the face plate 11 and the backing plate 13. The purpose of the insulating layer 29 is to further absorb sound and heat that might be generated in the ceiling void and would otherwise pass through the panel. The provision of the insulating layer 29 enables the thickness of the insulating layer 12 to be reduced which results in a corresponding reduction in the thickness and weight of the panel thereby. facilitating transportation and installation of the panel. The additional insulating layer 29 would desirably be enclosed within a foil envelope for example to prevent migration of fibrous or particulate material.

It is envisaged that panels of widths in the range 200 to 600 mm and lengths up to 3000 mm will typically be available although these dimensions are not intended to be limiting. Typically the facing and backing plates may be made from 0.6 mm or 0.7 mm electro-galvanised mild steel with at least the face plate finished with for example a polyester powder paint to a smooth or textured finished as required.

The panel has been described herein in relation to a so-called hang-on suspended ceiling arangement.

However, it should be understood that the invention is intended to cover panels for other ceiling arrangement such as for example clip-in or lay-in arrangements.

Referring now to Figures 9 and 10 an apparatus for use in manufacturing the above described and similar ceiling panels comprises a supporting bed 30 made from for example 2" thick aluminium plate which provides support for several sets of supporting members 31,32,33 along the length of the bed 30. Each set of supporting members supports a mounting bar 34 which extends across the width of the bed and provides support for a pair of roller beds 35,36 which extend along the length of the supporting bed 30 and are adjustably mounted to the mounting bar 34 by way of adjustable carrier members e.g. 37,38 which enable the relative positions of the roller beds 35,36 and associated parts of the apparatus to be adjusted for the manufacture of panels of differing widths.

At least one hydraulic riser column 39 is provided on each of the roller beds 35,36 each riser column comprising a central member 40 mounted to the respective roller bed 35,36 and a hydraulic riser 41 which supports a tagging bar 42.

A number of stitching heads or taggers 43 are provided along the length of the tagging bar 42 and are arranged to be brought into contact with the upwardly extending edge portions of the panel by movement of the hydraulic riser column 39. The taggers 43 are per se known and operate to "stitch" two sheet metal panels together by releasing pairs of opposed tags out of the contiguous panels and bending the tags over to secure the panels together.

In use, preformed components of the panel 10 are put together and placed on rollers e.g. 44,45 provided along the length of the roller beds for final assembly. That is to say, a faceplate 11 is placed on the rollers with a layer of insulating material 12 sandwiched between the faceplate 11 and a backing plate 13 so that the edges of the faceplate and backing plate can be tagged together by the taggers 43. Once the panel has been positioned lengthwise on the roller beds 35,36, hydraulic centering rams 46 are actuated to position the edges of the panel under the taggers 43. The hydraulic risers are actuated to lower the respective tagger bars to position the taggers over the edges of the panel and the taggers are energised to tage the edges of the faceplate and backing plate together to complete assembly of the panel. The hydraulic risers are then actuated to raise the taggers clear of the completed panel which is removed from the machine.

It has been found that unless each side of the panel is precisely positioned in relation to the respective taggers, the panel tends to be pulled to one side or the other during the tagging operation.

With the taggers on both sides of the panel pulling the panel out of position distortion in the finished panel can occur. This problem tends to arise because of variations in panel widths within acceptable manufacturing tolerances and is simply overcome by arranging for the taggers associated with one side of the panel only to be energised to tag that side of the panel first and then for the taggers associated with the other side to be energised.

Claims (12)

CLAIIYS :

1. A panel for use in, for example, a suspended ceiling, which panel comprises a primary plate having a portion defining an insulation receiving tray, insulating material disposed in said tray, and retaining means placed over said insulating material and held thereover by substantially vertical members secured to upturned edge portions on the primary plate thereby to retain the insulating material in position and provide rigidity to the panel.

2. A panel according to claim 1, wherein the insulating material comprises a mineral wool matt wrapped in an encasing envelope.

3. A panel according to claim 1 or 2, wherein the said insulation receiving tray portion is perforated in order to enhance sound absorbing characteristics of the panel.

4. A panel according to any preceding claim, wherein the retaining means and the substantially vertical securing members are integrally formed.

5. A panel according to any of claims 1 to 3, wherein the substantially vertical members comprise flange members secured to edge portions of the primary plate.

6. A panel according to claim 5, wherein the flange members are welded to the primary plate.

7. A panel according to claim 5, wherein the flange members are stitched to the primary plate.

8. A panel according to any preceding claim, wherein the retaining means comprises a metal panel.

9. A panel according to any of claims 1 to 7, wherein the retaining means comprises a plasterboard panel.

10. A panel according to any preceding claim wherein a further layer of insulating material is disposed on said retaining means.

11. Apparatus for use in manufacturing a panel as claimed in any one of the preceding claims.

12. A panel substantially as described herein with reference to Figures 3 to 8 of the accompanying drawings.