IES20070254A2

IES20070254A2 - An alarm box

Info

Publication number: IES20070254A2
Authority: IE
Inventors: Gerard Kelly
Original assignee: Gerard Kelly
Priority date: 2007-04-11
Filing date: 2007-04-11
Publication date: 2007-10-17

Abstract

An alarm box comprising a base 10 for mounting on a building wall and containing an alarm, and a lid 12 for opening and closing on the base. The base includes a levelling device comprising a toroidal housing 34 in a plane substantially parallel to the wall, and a ball freely contained in the housing. Apertures 40, 42 through which the ball is visible when the aperture is at the lowest point define angular orientations of the base which are 90 degrees apart. <Figure 7>

Description

This invention relates to an alarm box.

IE 0 / 0 254 An alarm box, also referred to as a bell box, is a housing containing a siren, bell or other audible and/or visual alarm which is normally fitted, in an inaccessible but visible position, to an exterior wall of a building to be protected by the alarm.

According to the present invention there is provided an alarm box comprising a base for mounting on a building wall and containing an alarm, and a lid for opening and closing on the base, wherein the base includes a levelling device comprising a concave surface which curves through an angle of at least 90 degrees in a plane substantially parallel to the wall, a ball freely resting on the concave surface, and means for indicating when the ball is at either one of at least two distinct positions along the concave surface.

Preferably the concave surface forms part of a housing containing the ball, the indicating means comprising respective apertures in the housing at said two distinct positions through which the ball is visible.

In a preferred embodiment the housing comprises a toroid.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: FIG 1 is a perspective view of an embodiment of alarm box according to the invention with its lid closed. « 070 254 FIG 2 is a perspective view of the alarm box with its lid open.

FIG 3 is a perspective close-up view of the interior of the alarm box showing the hinge and levelling device.

FIG 4 is a horizontal cross-section of the alarm box.

FIG 5 is close-up view of the left hand end of FIG 4.

FIG 6 is a close-up plan view of the interior of the alarm box showing the levelling device.

FIG 7 is a close-up perspective view of the interior of the alarm box showing the levelling device.

FIG 8 is a close-up perspective view of the interior of the alarm box showing the illumination device.

In this specification terms such as vertical, horizontal, right and left are used to facilitate description and refer to the orientation of the alarm box as shown in FIGS 1 to 3. However, the use of such terms does not imply any particular orientation of the alarm box in use.

Referring to the drawings, an alarm box comprises a base 10 and a lid 12, both moulded from plastics material. In use the base 10 is fixed flat against a vertical wall 14, FIGS 4 and 5, using screw-fixings (not shown). The base 10 contains an alarm, such as sirens 16, and associated electrical switching circuitry. Boxes of this type are « 070254 very well known, and no further description of the interior working components is thought necessary.

The lid 12 is hinged to one edge of the base 10, in FIGS 1 to 5 the left hand edge 18, for opening and closing on the base in the manner of a book cover by rotation about a vertical hinge axis 20 (FIG 2). The hinge comprises upper and lower coaxial pivot pins 22 carried by laterally extending supports 24 on the base 10. The inside of the lid has upper and lower pairs of flanges 26, each flange having a respective slot 28 open at one end. All four flanges have substantially the same dimensions and are in register in the vertical direction. Each pin 22 is slidably received into a respective pair of slots 28 with its support 24 located between the corresponding pair of flanges 26.

Normally, with the base 10 fixed to the wall 14, the pins 22 are located at the far (i.e. closed) ends of their respective slots 28, as shown in FIGS 2 to 5, so that the lid 12 can be swung wide open (FIG 2) or closed onto the base 10 (FIG 1) by rotation about the axis 20. When the lid 12 is swung wide open it is held in that position by resilient detents 30 which engage behind raised formations 32 on the lid. The lid is closed by overcoming the resilient detent force.

In addition, with the base 10 still fixed to the wall 14, if the lid 12 is opened by about 15 degrees so that the free end of the lid, i.e. the end opposite to the axis 20, is able to clear the base 10, the lid 12 can be fully detached from the base 10. This is achieved by sliding the lid generally parallel to the wall, normal to the hinge axis 10, so that the pins 22 slide along the slots IE 0 70 254 and exit their open ends. This allows the lid 12 to be completely removed from the base 12, and correspondingly re-attached, for easier servicing of the internal components of the alarm box. It also allows the base to be fixed to the wall before fitting the lid.

However, with the base 10 fixed to the wall 14, the lid 12 can only be completely detached from the base 10 over a small angle of opening, since when the lid 12 is hinged open beyond a certain point the lid cannot be fully detached from the base 10 by the pins 22 sliding along the slots 28 due to interference by the wall.

The alarm box includes a levelling device for allowing a user to accurately level the base 10 on a wall 14. The levelling device comprises a toroidal housing 34 fitted to the base 10 such that the toroid lies substantially parallel to the wall 14 when the base is mounted on the wall. A ball 36 (FIG 6) is freely contained in the housing 34 so that it can always come to rest at the lowest point of the concave surface formed by the inside surface of the outer wall 38 of the toroid. The housing 34 has two apertures 40, 42 disposed 90 degrees apart around the toroid, the ball 36 being visible through an aperture when that aperture is at the lowest point.

The positions of apertures 40, 42 are selected so that when the aperture 40 is at the lowest point (FIGS 3, 6 and 7) and the ball 36 visible therethrough, the base 10 is horizontal on the wall 14, whereas when the aperture 42 is at the lowest point the base 10 is vertical on the wall 14. Preferably the housing 34 is rotatable relative to the base 10 in the plane substantially parallel to the wall 14. Scales 44 allow the angular position of the Ο 7 Ο 2 5 4 housing 34 relative to the base 10 to be accurately determined. This allows a fine adjustment to be made to the angular orientation of the base on the wall.

A pair of LEDs 46 is mounted on the base 10, FIGS 2 and 8. These illuminate the interior of the base when the lid 12 is opened. The LEDs 46 are operated by a microswitch (not shown) on the base 10 which is actuated by an arm 48 carried by the lid 12. Normally, when the lid is closed, the arm 48 engages the microswitch to hold it off. When the lid is opened the arm 48 disengages the microswitch to allow the latter to turn on, so lighting the LEDs. The LED power is derived form the internal circuitry of the alarm box.

The LEDs 46 preferably primarily illuminate a region of the base 10 which, in use, contains contacts (not shown) by which the alarm box is connected to external electrical circuitry in the wall 14.

The invention is not limited to the embodiment described herein which may be modified or varied without departing from the scope of the invention.

Claims

1. An alarm box comprising a base for mounting on a building wall and containing an alarm, and a lid for opening and closing on the base, wherein the base includes a levelling device comprising a concave surface which curves through an angle of at least 90 degrees in a plane substantially parallel to the wall, a ball freely resting on the concave surface, and means for indicating when the ball is at either one of at least two distinct positions along the concave surface.

2. An alarm box as claimed in claim 1, wherein the concave surface forms part of a housing containing the ball, the indicating means comprising respective apertures in the housing at said two distinct positions through which the ball is visible.

3. An alarm box as claimed in claim 2, wherein the housing is rotatable relative to the base in said plane substantially parallel to the wall.

4. An alarm box as claimed in claim 2 or 3, wherein the housing comprises a toroid.

5. An alarm box as claimed in any preceding claim, wherein the two distinct positions are substantially 90 degrees apart.