GB2372266A

GB2372266A - Anchoring devices in apertures in buildings

Info

Publication number: GB2372266A
Application number: GB0103807A
Authority: GB
Inventors: Jeremy Buss
Original assignee: WEAC Ltd
Current assignee: WEAC Ltd
Priority date: 2001-02-16
Filing date: 2001-02-16
Publication date: 2002-08-21
Anticipated expiration: 2021-02-16
Also published as: GB2372266B; GB2372266A8; GB0103807D0

Abstract

Apparatus for anchoring a device in an aperture in a building, e.g. a smoke detector 10 in a ceiling 8, comprises a mounting 12 and a device 10, the mounting component 12 being releasably attachable both to surface 8 and to device 10, device 10 being attachable to mounting 12 by relative movement in either of two opposed directions. For example mounting 12 may be a double bayonet arrangement which allows smoke detector 10 to be attached either from above or below, regardless of whether the ceiling is present. This allows smoke detectors to be installed and tested in a building before the ceilings are all installed.

Description

1 2372266

C695.00/W

Title: Apparatus and Method for Anchoring Devices in Buildings Field of the Invention

This invention relates to apparatus for anchoring devices in buildings, particularly to interior surfaces thereof, and to a method of anchoring devices in buildings.

Background of the Invention

Modern buildings such as offices, leisure facilities, car parks and the like generally contain large numbers of devices which are positioned within the building, and are connected (e.g. via cables, ducting, bunking, pipework and the like) to other components, so as to form a system. Such "systems" normally comprise electronic and/or electrical components and therefore include electrical cables and wires for conducting power and/or electrical signals to and/or from the various components. Examples of such systems include lighting systems, fire alarm systems and burglar/intruder alarm systems. Thus, for example, a fire alarm system will generally comprise a plurality of smoke detectors, anchored to an interior surface (e.g. floor, wall or ceiling) of a building.

Conventionally devices forming part of a system are installed in a building in a two step process. In a first step (commonly referred to in the art as "first fix"), the necessary cabling is installed in the building, typically in the void spaces above ceilings and between walls.

Optionally the first fix also includes fitting of mounting boxes to the ends of the cables, via retaining glands provided on or fitted to the mounting box.

In the second step ('second fix"), the cables are offered up to and correctly terminated in the relevant device (e.g. smoke detector unit). With the mounting box on one side of the surface, and the device on the other side, fixing screws are passed through the device and the

surface of the building into the mounting box, thereby sandwiching the surface between the mounting box and the device, anchoring the device in place.

The use of a mounting box is essential in order to avoid strain on the terminations of the cables inside the device. If a termination is broken the device will normally be rendered inoperable. Moreover, a short circuit may be formed, rendering the device possibly dangerous or increasing the risk of sparking and fires.

However, this two step process outlined above is not without its disadvantages. Although the cabling can (and generally must) be fined prior to installation of the relevant surface (typically a ceiling), the devices themselves cannot be fitted and connected until the surface has been installed. For many types of system, testing and commissioning cannot begin until all the devices making up the system have been fitted. This in turn means that the ceilings (or other surface) throughout an entire section of the building (or possibly even throughout the building) must be completed before testing and commissioning can commence.

Some systems try to reduce the amount of time required for the second fix by provision of cabling that is terminated into pre-formed sockets at the first fix stage of the installation.

This enables some initial testing to be performed. However it introduces additional cost and, in any event, is prohibited in some systems such as fire alarm systems. Indeed, fire alarm systems introduce particular difficulties as, in many countries, it is a legal requirement that these are fully operational before the building can be opened to staff and the general public.

Summary of the Invention

In a first aspect the invention provides apparatus for anchoring to a surface of a building a device forming part of a system, the apparatus comprising a mounting component and a device component, wherein the mounting component is releasably attachable to both the surface and to the device component and serves to anchor the device to the surface, and wherein the mounting component may be released from the device component by relative movement of the two components in either of two opposed directions.

Typically the surface is an interior surface, generally a ceiling. The device present in the device component will normally be any electrical or electronic device, such as a smoke detector, a light source, infra-red detector component of a burglar alarm, and the like.

In a preferred embodiment, the mounting component takes the form of a circular annulus, such as a collar or bezel, defining a central space within which the device component is accommodated. In one such embodiment the device component is provided with lugs (typically two or more) which are received within corresponding suitably shaped and dimensioned channels or grooves formed in the mounting component, such that the two components fit together with a bayonet-type engagement. The bayonet fitting is such that the lugs of the device component can enter or exit the corresponding channels or grooves from both an upper surface and from a lower surface of the mounting component and, in an intermediate position are releasably locked in place in the mounting component by engagement with, for example, corresponding detents. The detents may, for example, be formed of a resiliently deformable material and form a snap- fit locking action with the lugs.

Accordingly, in preferred embodiments the device component can be passed through the mounting component in either of two opposed directions, but can also be retained in engagement with the mounting component.

The mounting component may be anchored to the surface by any conventional means, e.g. by fixing screws, or by a snap-fit action. The present invention thus allows a device to be anchored in position to a surface of a building without having to form a sandwich of device and mounting box on opposed sides of the surface.

The arrangement of the present invention confers a number of significant advantages over conventional techniques of anchoring devices. For example, the present invention allows termination, testing and commissioning of a device without the need for the surface to be in place, and subsequent anchoring of the device to the surface whilst the device remains operational. Further the invention allows for the device to be later detached from the

surface, again whilst the device remains operational, by disengagement of the device component from the mounting component. The invention also allows for installation and removal of a device from either side of the surface, without the need to access the other side of the surface.

In a second aspect, the invention provides a method of anchoring a device to a surface of a building, the method comprising use of an apparatus as defined above.

The invention will now be further described by way of illustrative example and with reference to the accompanying drawings, in which: Figure 1 is a schematic sectional view showing a conventional arrangement (not in accordance with the invention) for anchoring a device to a ceiling; Figure 2 is a schematic sectional view showing an arrangement in accordance with the invention for anchoring a device to a surface of a building; Figures 3 and 4 show top and bottom elevations respectively of a mounting component of apparatus in accordance with the invention; Figure 5 is a perspective view of a mounting component of a further embodiment of apparatus in accordance with the invention; Figure 6 is a side elevation of a mounting component of a further embodiment of apparatus in accordance with the invention; and Figure 7 is a side elevation of a part of the mounting component depicted in Figure 6. shown in isolation from the rest of the mounting component for clarity.

Examples

A conventional arrangement for anchoring a device, such as a smoke detector, to the ceiling of a building is illustrated schematically in Figure 1. Cables 2A, 2B are secured to

respective glands 4A, 4B provided on mounting box 6. These components are installed in a first fix procedure. Once the ceiling 8 is put in place, the smoke detector unit 10 may be electrically connected to the cables 2A, B and anchored to the ceiling by fixing screws 9, thereby sandwiching the ceiling between the mounting box 6 and the detector unit 10. This arrangement involves a number of disadvantages as explained above.

In contrast, apparatus in accordance with the invention is illustrated schematically in section in Figure 2.

In the embodiment of the invention illustrated in Figure 2, the apparatus comprises a mounting component 12 in the form of a circular collar or bezel, and a device component 14.

The device component 14 includes glands 4A, B and associated fixtures found in conventional apparatus for securing cables. The mounting component 12 and device component 14 both comprise injection mouldings formed from a synthetic plastics material, such as ABS, or formed from investment cast metal. The mounting component 12 is located within a circular aperture provided in the ceiling 8 and may be releasably attached to the ceiling by any suitable means (e.g. fixing screws, not shown). The device component 14 is held in engagement with the mounting component 12 by lugs (not shown) and is thus anchored via the mounting component 12 within, but is not directly attached to, the ceiling 8.

The device component 14 comprises an otherwise conventional smoke detector unit 10, which is retained in the device component by fixing screws.

The device component 14 may be released from the mounting component 12 by relative movement of the two components in either of two opposed directions. Accordingly, the mounting component 12 being secured to the ceiling 8, downward movement of the device component 14 into the room, or upward movement into the void space above the ceiling is permissible to release the device component 14 from the mounting component l9. no part of the device component being wider (when the device is being removed) than the widest path through the mounting component.

Two similar embodiments are illustrated in Figures 3-5. Figures 3 and 4 are top and bottom elevations respectively of a mounting component of apparatus in accordance with the present

invention. Figure S shows (to a different scale) a perspective view of a different mounting component. in particular Figure 5 shows a double rightangled channel or groove 20 provided in the mounting component 12 which accommodates a corresponding lug provided on the device component. The channel 20 includes a detent 22 which engages with the lug to anchor the device component in position. Relative rotational and translational movement of the two components allows them to be engaged and disengaged as desired.

In other embodiments (not illustrated) operation of a switch or other mechanism engages and disengages lugs on the device component with cooperating channels or grooves provided on the mounting component (or vice versa).

If desired, the lugs can be formed of a resiliently deformable material to assist in engagement and disengagement with their respective co- operating channels or grooves. Alternatively, the lugs may be retractable (e.g. spring-mounted, or mounted on other biasing means) as desired. As explained above, the mounting component may be releasably attached to the ceiling by any suitable means. Conveniently these will comprise fixing screws, but other fixing means can be envisaged. For example, as illustrated in Figure 6, the mounting component may be provided with a plurality of tabs 24, attached to the mounting component by a resiliently deformable hinge portion. When inserted into the ceiling or other surface, the tabs 24 are substantially aligned with the body of the mounting component, but may be bent outwards to engage with the rear surface and secured in place by cheap, disposable ties formed from synthetic plastics material (and well known to those skilled in the art). To remove the mounting component from the ceiling simply requires that the ties be cut, the resiliently deformable hinge returning the tabs to their upright position. In order to obtain access to the ties it may be necessary first to release the device component from the mounting component.

. Figure 7 illustrates the principle of operation in relation to a single tab.

Those skilled in the art will appreciate that other embodiments, within the general concept defined herein, may be envisaged and all such embodiments are intended to be encompassed within the scope of the following claims.

Claims

1. Apparatus for anchoring to a surface of a building a device forming part of a system. the apparatus comprising a mounting component and a device component, wherein the mounting component is releasably attachable to both the surface and to the device component and serves to anchor the device component by relative movement of the two components in either of two opposed directions.

2. Apparatus according to claim 1, for anchoring a device to a ceiling.

3. Apparatus according to claim 1 or 2, wherein the device comprises an electrical or electronic component to be electrically connected to cables provided in the building.

4. Apparatus according to any one of the preceding claims wherein the device forms part of a fire alarm or burglar alarm system.

5. Apparatus according to any one of the preceding claims, wherein the device comprises a smoke detector.

6. Apparatus according to any one of the preceding claims, wherein the mounting component comprises a circular collar or bezel defining a central space, within which space the device component is accommodated.

7. Apparatus according to any one of the preceding claims, wherein the device component may be released from the mounting component without releasing the mounting component from the surface.

8. Apparatus according to any one of the preceding claims, wherein the device component is retained within the mounting component by interaction of one or more lugs provided on one component with corresponding cooperating detents provided on the other component.

9. Apparatus according to any one of the preceding claims, wherein the device componen, is attached to the mounting component by a bayonet-type engagement.

10. Apparatus according to any one of the preceding claims, wherein the device component can be released from the surface whilst remaining an operational part of the system,

11. A method of anchoring to a surface of a building a device forming part of a system. the method comprising' use of apparatus in accordance with any one of the preceding claims.

12. Apparatus substantially as hereinbefore described and with reference to the accompanying drawings.