GB2490893A

GB2490893A - Angularly adjustable mounting

Info

Publication number: GB2490893A
Application number: GB1108121.3A
Authority: GB
Inventors: Daniel William Carter; Gareth Mark Dibden; Jonathan Kevin Ben; Janusz Lucien Holland
Original assignee: Fire Fighting Enterprises Ltd
Current assignee: Fire Fighting Enterprises Ltd
Priority date: 2011-05-13
Filing date: 2011-05-13
Publication date: 2012-11-21
Also published as: GB201108121D0

Abstract

An angularly adjustable mounting for a device, such as an optical beam smoke detector system comprises: a first adjustment housing 2 adapted to be fixedly secured to a mounting surface 6, for example a wall ; a second adjustment housing 1 mounted on the first adjustment housing and interfacing therewith at a first part-cylindrical interface 5 and constrained for relative sliding movement over that interface to tilt about a first axis (9) which is fixed relative to the first adjustment housing; and a support housing for the device (8) eg a lens, mounted on the second adjustment housing and interfacing therewith at a second part-cylindrical interface and constrained for relative sliding movement over that interface to pan about a second axis which is fixed relative to the second adjustment housing and is skew relative to the first axis; and an adjustment mechanism 7 within each adjustment housing for causing the respective relative sliding movement, whereby to pan and tilt the device.

Description

I

ANGULARLY ADJUSTABLE MOUNTING

This invention relates to an angularly adjustable mounting for a device such as an optical beam smoke detector. The invention is broadly applicable across a range of technologies, for example for mounting lighting systems, security cameras and other domestic and industrial devices.

Optical beam smoke detectors typically comprise a transmitter, a receiver and a controller, this system typically being called an end to end or linear type. Alternatively, such detectors may comprise a transceiver, i.e. a transmitter and receiver integrated into one housing, a reflector and a controller. Such a system is typically called the reflective type. In both these examples, the controller could be integrated into the receiver or the transceiver.

Optical beam smoke detectors require the light-emitting, light-reflecting and/or light-receiving elements of the system to be aligned so as to form an operational system.

Alignment means steering the elements of the system so that each points to its reciprocating element. The two typical methods of alignment are manual and motorised alignment. Manual alignment requires the installer of the system to align the beam either by hand, using thumb wheels or the like, or with a hand tool. Motorised alignment uses motors to move the beam to achieve alignment, and the control of the motor or motors could be by intelligence within the system resulting in minimal installer input.

Typically, the method of alignment has an impact on the form of the product, such that its size is increased, and its shape needs to allow for the alignment mechanism. In some examples, the pads of the optical beam system need to be disassembled to allow access to the adjustment mechanism.

In a number of installation environments, it is desirable for the optical beam smoke detector elements to be as small and as compact as possible so that they do not impact on the appearance of the environment in which they are installed. From an installation viewpoint, optical beam smoke detector systems need to be simple and intuitive to install and to align, so that the installer immediately knows how to adjust the optical beam for alignment.

Accordingly, the purpose of the present invention is to improve upon existing alignment adjustment mechanisms suitable for optical beam smoke detectors to make them more compact and intuitively usable.

The present invention provides an angularly adjustable mounting for a device, comprising: a first adjustment housing adapted to be fixedly secured to a mounting surface; a support housing for the device, mounted on the first adjustment housing and interlacing therewith at a first curved interlace and constrained for relative sliding movement over that interlace to pan about a first axis which is fixed relative to the first adjustment housing; and an adjustment mechanism within the first adjustment housing for causing the relative sliding movement, whereby to position the device angularly.

The invention further provides an angularly adjustable mounting for a device, comprising: a first adjustment housing adapted to be fixedly secured to a mounting surface; a second adjustment housing mounted on the first adjustment housing and interlacing therewith at a first curved interface and constrained for relative sliding movement over that interlace to tilt about a first axis which is fixed relative to the first adjustment housing; a support housing for the device, mounted on the second adjustment housing and interfacing therewith at a second curved interlace and constrained for relative sliding movement over that interface to pan about a second axis which is fixed relative to the second adjustment housing and is skew relative to the first axis; and an adjustment mechanism within each adjustment housing for causing the respective relative sliding movement, whereby to position the device angularly in two axes.

In order that the invention may be better understood, a preferred embodiment will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Fig. 1 is a vertical cross-section through pad of a mounting embodying the present invention and showing an adjustment mechanism between two stages of the mounting; Fig. 2 is a cross-section corresponding to Fig. I but with the stages angularly displaced by the adjustment mechanism; Fig. 3 is a partial perspective view of the mounting of Figs. I and 2, partly broken away to illustrate one adjustment mechanism; Fig. 4 is a view corresponding to Fig. 3 and showing more of the carrier structure for the adjustment mechanism; Fig. 5 is a perspective view corresponding to Figs. 3 and 4 and including an adjustment housing around the adjustment mechanism; Figs 6a and 6b show different configurations of the entire mounting of Figs. I to 5, attached to a vertical support surface; and Fig. 7 is a perspective view of the adjustment housing of Figure 5.

One component of an optical beam smoke detector system, which may be for the receiver, the transmitter or the transceiver, is illustrated in Figs. I to 6. The mounting comprises a first adjustment housing 2 which is adapted to be secured to a mounting surface 6 such as a wall in a building. An additional fixture (not shown) may be included. A second adjustment housing I is mounted on the first adjustment housing 2 with which it interfaces at a first part-cylindrical interface, and is constrained for relative sliding movement over that interface to tilt about a first axis, at right angles to the plane of the paper in Figs. 6a and 6b, the first axis being fixed relative to the first adjustment housing 2. A lens housing 8 for the appropriate optical device such as a transmitter, receiver or transceiver, constitutes a support housing and is mounted on the second adjustment housing I. The lens housing 8 interfaces with the second adjustment housing I at a second pad-cylindrical interface, which has the same radius of curvature as the first pad-cylindrical interface in this example, although the radii could be different. The lens housing 8 is constrained for relative sliding movement over that interface to pan about a second axis which is fixed relative to the second adjustment housing and is skew relative to the first axis: in this example, the second axis is orthogonal to the first axis, and is vertical, and in the plane of the paper in Figs. Ba and 6b. In effect, the mounting provides for two stages of angular adjustment. The lens housing 8 may be adjusted by vertical tilting and by horizontal panning in the respective orthogonal axes. Vertical tilting is illustrated in Figs. 6a and 6b: in the configuration in Fig. 6a, the elements of the mounting are all aligned on the horizontal axis 9, and operation of an adjustment mechanism within the first adjustment housing 2 causes the lens housing 8 and the second adjustment housing I to be tilted together upwardly through an acute angle so that their axis 10 is above the horizontal axis 9. Similarly, although not illustrated, an adjustment mechanism inside the second adjustment housing I is operable to move the lens housing 8 angularly relative to the second adjustment housing 1 to provide horizontal panning movement, independently of any vertical tilting adjustment.

In this example, the angular range of adjustment from one adjustment stage is approximately 20°. The range depends on the device and the system involved.

The adjustment mechanisms within the first and second adjustment housings 1, 2 are substantially identical in this example, and will be described with reference to Figs. 1 to 4, which illustrate portions of two adjacent stages of the mounting. Figures 1 to 4 illustrate the adjustment of the first stage, nearer the support surface 6, but the adjustment of the second stage corresponds, albeit turned through a right-angle.

Each adjustment mechanism comprises a worm gear 4 mounted for rotation in an adjustment carrier 3 within the adjustment housing, which is shown in the drawings as the first adjustment housing 2, although it would apply equally to the second adjustment housing 1. The worm gear 4 meshes with an adjustment rack which is part-cylindrical, i.e. arcuate, and is formed integrally with the part-cylindrical surface at the end of the adjacent second adjustment housing 1. A thumb wheel 7 fixed to the worm gear allows it to be rotated for manual adjustment. The thumb wheel 7 projects from the adjustment housing.

A pair of tabs A are connected to the adjustment rack 5 and are guided by a curved plate which overlies the adjustment rack 5 and is connected to the side wall of the first adjustment housing 2 as shown in Figure 7. The plate has a key hole aperture 11 for allowing the plate to be mounted over the tabs A during assembly and then allowing the relative sliding movement of the base of the tabs along the key hole slot to take place as the tabs are constrained to move in the gap between the plate and the adjustment rack 5. This relative sliding movement is constrained to rotation about the fixed axis, so that there is relative sliding movement over the part-cylindrical interface.

The tabs A are integral with the adjustment rack 5. The plate with the key hole aperture 11 is an end surface of the adjustment housing 2. When the tabs have been located into the adjustment housing, the key hole 11 which allowed the assembly is blanked off by tabs (not shown) on the adjustment carrier 3. These match the key hole almost size for size. The adjustment rack is therefore constrained in all directions apart from the one path along which it is required to move. The undersides of tabs A slide across the part-cylindrical rear face of the adjustment housing.

The adjustment housing 2 has a circular aperture 12 in its side wall to accommodate a thumb wheel 7, described below, which is assembled with a snap fit into the worm gear.

Each housing 1, 2, 8 in this example has cylindrical side walls, although other shapes would be possible. The cylindrical shape is considered to be the most compact arrangement and the least visually obtrusive. Again in this example, each component has substantially the same diameter. In this example, the lens housing has a slightly smaller diameter than the second adjustment housing, which in turn has a slightly smaller diameter than the first adjustment housing. Thus the entire mounting may form a substantially cylindrical shape or tapering conical shape when the two adjustment mechanisms are centred, as shown in Fig. 6a. In this configuration, the cylindrical side walls are all substantially flush with each other.

Each adjustment worm gear 4 can be rotated either by the thumb wheel 7 as shown or, in other embodiments, with the use of a screwdriver or a hand tool (not shown) or even by an integrated electric motor or other motor (not shown). In a further alternative, a thumb wheel could be pushed and pulled such as to move perpendicularly to the adjustment housing axis: this in turn would act upon the adjustment rack, to provide relative angular movement.

In this example, the first adjustment housing 2 has a planar end surface perpendicular to the axis of the cylindrical side wall, for engagement with a mounting surface 6. This mounting surface may be another component onto which it engages via a bayonet fix.

At the other end of the first adjustment housing, there is the part-cylindrical interface.

The second adjustment housing I has part-cylindrical surfaces at each of its ends,

A

meeting the cylindrical side wall. The lens housing 8 has its part-cylindrical end surface meeting its cylindrical side wall at one end: the opposite end can be of any convenient shape, including the inclined flat surface as shown in Figs. 6a and 6b.

The mounting shown in Figs. 1 to 6 may be installed by securing a base plate (not shown) to the wall of a building, and then securing the end of the first adjustment housing 2 to the base plate for example by screws or by a twist fit such as with a bayonet coupling. In the case of manual adjustment, the angular position of the lens housing 8 is adjusted in the two orthogonal axes by appropriate operation of the thumb wheels 7 of each stage. In the case of automatic motorised adjustment, the position of the lens housing 8 may be adjusted by remote control. For optical beam smoke detector systems, the optical beam itself may be used for the alignment of the components of the system, using an appropriate optical-electrical feedback control system, which operates the motorised adjustment mechanisms.

The structure of the adjustment carrier 3 is such as to comply with the appropriate fire detector impact test standards. The spine of the carrier and the pair of tabs A contribute to retaining the worm gear 4 when the external cylinders are impacted. The other components of the structure such as tabs B contribute to strength and rigidity and enable the mounting to be assembled from separate plastics mouldings with a snap fit.

The worm gear and rack arrangement of the preferred embodiment is advantageous as it inherently resists back forces and impacts, providing stability to the relative angular position of each stage. However, it will be appreciated that the invention is applicable also to other adjustment mechanisms, manual or automatic.

Whilst the preferred embodiment is intended for supporting an optical device as part of an optical beam smoke detector system, the mounting could be used for any device to provide angular adjustment about two or more axes, relative to a reference support surface. The device could for example be a security camera or an electric light, or an antenna. Any electrical or optical connections to the device that is supported by the mounting could pass through the interior of the mounting through appropriate apertures (not shown) formed in the interfaces.

The mounting shown in the drawings is particularly compact and unobtrusive, with only the thumb wheels shown protruding from the cylindrical housing. Operation of the adjustment mechanisms during installation is particularly intuitive, since the shapes of the interfaces are apparent as curved lines when viewed from the exterior, and the thumb wheels are positioned at different stages along the longitudinal axis of the mounting so as to be identifiable for adjusting each stage.

In the preferred embodiment there are two stages of angular adjustment. There may however be at least one further adjustment stage, axially aligned with the first and second adjustment housings, for angular adjustment of the device about a further axis different from the first two axes. It is also possible to use only one adjustment housing, so as to provide only one adjustment stage, with angular adjustment about only one axis, The invention of using an internal adjustment mechanism and having a curved interface is equally applicable and still provides compactness and simplicity.

Instead of part-cylindrical interfaces, other curved interfaces are possible, in particular part-spherical interfaces, In this case, the join between the relatively moveable components appears to be linear in plan view and elevation.

Claims

SCLAIMS: 1. An angularly adjustable mounting for a device, comprising: a first adjustment housing adapted to be fixedly secured to a mounting surface; a support housing for the device, mounted on the first adjustment housing and interfacing therewith at a first curved interface and constrained for relative sliding movement over that interface to pan about a first axis which is fixed relative to the first adjustment housing; and an adjustment mechanism within the first adjustment housing for causing the relative sliding movement, whereby to position the device angularly.
2. A mounting according to claim 1, in which the adjustment mechanism comprises a worm gear cooperating with an arcuate rack on the support housing at the curved interface.
3. An angularly adjustable mounting for a device, comprising; a first adjustment housing adapted to be fixedly secured to a mounting surface; a second adjustment housing mounted on the first adjustment housing and interfacing therewith at a first curved interface and constrained for relative sliding movement over that interface to tilt about a first axis which is fixed relative to the first adjustment housing; a support housing for the device, mounted on the second adjustment housing and interfacing therewith at a second curved interface and constrained for relative sliding movement over that interface to pan about a second axis which is fixed relative to the second adjustment housing and is skew relative to the first axis; and an adjustment mechanism within each adjustment housing for causing the respective relative sliding movement, whereby to position the device angularly in two axes.
4. A mounting according to claim 3, in which the first and second axes are orthogonal, whereby the device may be panned horizontally and tilted vertically.
5. A mounting according to claim 3 or claim 4, in which the first and second adjustment mechanisms are substantially identical.
6. A mounting according to any of claims 3 to 5, comprising at least one further adjustment stage axially aligned with the first and second adjustment housings, for angular adjustment of the device about a further axis different from the other axes.
7. A mounting according to any preceding claim, in which the interface is, or interfaces are, part-cylindrical.
8. A mounting according to any of claims 1 to 6, in which the interlace is, or interfaces are, part-spherical.
9. A mounting according to claim 3, in which the first adjustment mechanism comprises a worm gear cooperating with an arcuate rack on the second adjustment housing at the curved interface, and the second adjustment mechanism comprises a worm gear cooperating with an arcuate rack on the support housing at the curved interface.
10. A mounting according to claim 2 or claim 9, in which the or each worm gear has a mechanism for manually rotating it.
11. A mounting according to claim 2 or claim 9, in which the or each worm gear has a motorised rotational drive.
12. A mounting according to claim 2 or claim 9, in which the or each worm gear is either manually rotatable or has a motorised rotational drive.
13. A mounting according to claim 3 or any claim dependent on claim 3, in which each adjustment housing has a generally cylindrical side surface meeting its curved surface which is at an end, the first and second axes being orthogonal to the principal axes of the cylindrical housings which coincide when the adjustment housings are centred angularly.
14. A mounting according to claim 13, in which the first and second adjustment housings have substantially the same diameter so that their cylindrical surfaces can be flush with each other. In
15. A mounting according to claim 13 or claim 14, in which the support housing has a generally cylindrical side surface meeting its part-cylindrical surface which is at an end.
16. A mounting according to claim 15, in which the diameter of the support housing is substantially the same as that of the first and second adjustment housings so that their cylindrical surfaces can all be flush with one another.
17. A mounting according to claim 3 or any claim dependent on claim 3, in which the radius of curvature of the curved interfaces is the same.
18. Apparatus comprising an optical beam transmitter and/or receiver and/or reflector device mounted in the support housing of a mounting according to any preceding claim.
19. Apparatus substantially as described herein with reference to the accompanying drawings.