GB2045327A

GB2045327A - Suspended Ceilings

Info

Publication number: GB2045327A
Application number: GB7909347A
Authority: GB
Original assignee: British Steel Corp
Current assignee: British Steel Corp
Priority date: 1979-03-16
Filing date: 1979-03-16
Publication date: 1980-10-29

Abstract

A system for assembling a suspended ceiling the system comprises metal planks 1 flanged at their longitudinal edges 7 for arrangement horizontally with the flanges of adjacent planks in contact and resilient metal hangers 2 having portions 8 biassed towards each other to form a resilient clamp to receive and grip the adjacent flanges of the planks so that the planks can be suspended from the hangers, wherein each hanger is formed with a chamber 9 extending from the portions and adapted to receive the flanges 7 which, in use, divide the chamber into two parts, one part 10 of the chamber containing a material 12 which expands upon the application of sufficient heat and the flanges having openings 16 alignable within the chamber to enable the material to expand from one part 10 to the other 11, via the openings. <IMAGE>

Description

SPECIFICATION Improvements in Suspended Ceilings The present invention relates to a system for assembling a suspended ceiling in a prefabricated building.

Conventional systems for assembling a suspended ceiling generally comprise metal planks flanged at their longitudinal edges which are arranged in rows horizontally and are suspended from resilient metal hangers. The flanges of the adjacent planks are in contact and pass through a resilient clamp formed by biassed portions at the lower ends of the hangers so that the portions grip the flanges resiliently to suspend the planks. The hangers themselves are secured to longitudinally extending beams which are secured to transverse beams supported by opposite walls of the room or space.

One problem with this type of system is that in the event of a localised fire in one room, the hangers can expand and/or distort with the heat to such an extent that the portions gripping the flanges can re-open and the planks can fall away from the hangers. The fire may then spread to rooms both above and adjoining the room on fire.

It is therefore an object of the present invention to provide a system which overcomes the problem.

According therefore to the present invention there is provided a system for assembling a suspended ceiling, the system comprising metal planks flanged at their longitudinal edges for arrangement horizontally with the flanges of adjacent planks in contact and resilient metal hangers having portions biassed towards each other to form a resilient clamp to receive and grip the adjacent flanges of the planks so that the planks can be suspended from the hangers, wherein each hanger is formed with a chamber extending from the portions and adapted to receive the flanges which, in use, divide the chamber into two parts, one part of the chamber containing a material which expands upon the application of sufficient heat and the flanges having openings alignable within the chamber to enable the material to expand from one part to the other part via the openings.

Preferably the chamber comprises two compartments forming the parts.

Suitably the hanger has further portions leading from the upper end of the chamber and biassed towards each other to form a resilient clamp to receive the ends of the flanges whereby the portions can grip the flanges resiliently.

Conveniently fire resistant insulating material is provided to be laid on each plank before suspension from the hangers.

An embodiment of the invention will now be particularly described with reference to the accompanying drawings.in which Figure 1 shows a cross section of a portion of a suspended ceiling, Figure 2 is a cross section of the components of the system, and Figure 3 is a close up view of the hanger chamber and associated parts after the heat sensitive material has expanded during a fire.

Referring to the drawings, the system comprises planks 1, hangers 2 and fire resistant material 3. In use, the hangers 2 are suspended from channel section beams 4 which run longitudinally of the room in which the ceiling is to be assembled These beams 4 are themselves suspended from transverse beams 5 which are supported on the walls 6 of the room. The floor (not shown) of the room above is laid across the transverse beams 5.

The planks 1 comprise steel sheets which are provided at their longitudinal edges with flanges 7 (Figures 2 and 3) which extend at right angles to the plane of the sheet. The planks 1, in use, are arranged in horizontal rows extending longitudinally of the room with their adjacent flanges 7 in contact and gripped by the hangers 2 in the manner to be described. While not shown, there are several hangers 2 spaced along the length of the planks 1 to enable the planks 1 to be suspended securely.

Referring to Figure 2, the hangers 2 comprise a thin steel strip bent or otherwise formed into a generally butterfly type shape. The hangers 2 are so designed that lower portions 8 are biassed towards each other to form a resilient clamp to receive and grip the adjacent flanges 7 of the planks 1 for suspension. Above the portions 8, a two compartment open ended chamber 9 is formed, the two compartments being designated 10 and 11 respectively. Compartment 10 contains a material 12 which expands upon the application of sufficient heat. Such a material is generally known as an "intumescent" material and a suitable compound is known as "Intugard" (Trade Mark).

This material 12 is injected into the compartment during the fabrication of the hanger 2 by roll forming. The other compartment 11 is empty to enable the material 12 to expand into it.

The upper end of the chamber 9 is provided with further portions 1 3 biassed towards each other to form another resilient clamp to receive and grip the ends of the flanges 7.

Above portions 13 the main body 14 of the hanger 2 is located which forms a generally triangular chamber with flattened elongations 1 5 at the base of the triangle.

The flanges 7 are provided with rows of equispaced apertures 1 6 along their length. The apertures 1 6 can be spaced about four feet apart but the spacing can be varied to suit requirements.

Adjacent apertures 1 6 in adjacent plank flanges 7 are alignable as shown in Figures 2 and 3 to enable the intumescent material 12 in compartment 10 to expand via the apertures 1 6 into compartment 12 during a fire as shown in Figure 3. Thus should the hanger 2 expand as a result of heating so that the portions 8 and 1 3 separate to free the plank flanges 7 from the clamping effect, the intumescent material will, by expansion, form a key to support the flanges 7 and maintain the planks 1 in position. Thus the room or space containing the assembly will be sealed off from other vertically and horizontally adjacent rooms should a fire break out in that room so that the risk of spread of the fire to the other rooms is greatly reduced or even eliminated altogether.

Furthermore, boards 3 which rest on the upper surface of planks 1 and which are of a heat insulating material such as asbestos, further reduce the risk of the fire spreading by providing a heat insulating blanket over the ceiling area.

The system is assembled easily in the following manner. The hangers 2 are firstly secured to the channel beams 4 by conventional screw fittings.

There will be several hangers 2 in each longitudinal row. Next, the insulating boards or blankets 3 are laid on the top surface of the planks 1. The planks 1 with adjacent flanges 7 touching and with adjacent apertures 16 aligned, are then lifted and finally the flanges 7 are pushed between the clamping portions 8 and 13 of the hangers 2.

Claims

1. A system for assembling a suspended ceiling, the system comprising metal planks flanged at their longitudinal edges for arrangement horizontally with the flanges of adjacent planks in contact and resilient metal hangers having portions biassed towards each other to form a resilient clamp to receive and grip the adjacent flanges of the planks so that the planks can be suspended from the hangers, wherein each hanger is formed with a chamber extending from the portions and adapted to receive the flanges which, in use, divide the chamber into two parts, one part of the chamber containing a material which expands upon the application of sufficient heat and the flanges having openings alignable within the chamber to enable the material to expand from one part to the other, via the openings.

2. A system as claimed in claim 1 in which the chamber comprises two compartments forming the parts.

3. A system as claimed in claim 1 or claim 2 in which the hanger has further portions leading from the upper end of the chamber and biassed towards each other to form a resilient clamp to receive and grip the ends of the flanges.

4. A system as claimed in any preceding claim in which fire resistant insulating material is provided to be laid upon the upper surface of each plank before suspension from the hangers.