An electric lighting unit

Abstract

 An electric lighting unit has a casing (10) connectibleto a wall or ceiling and an assembly of a high voltage gear tray (11), a fluorescent tube (12) and a diffuser (13) pivotally connected to the casing (10) for movement between a position where the high voltage gear tray (11) is concealed within the casing (10) and a position where it is clear of the casing (10) for servicing purposes. Additionally, a wal; (19) of the assembly is movable to permit diffuser (13) and fluorescent tube (12) removal.

Description

[0001] This invention relates to an electric lighting unit and especially an electric lighting unit having an emergency facility, that is battery operated on mains failure.

[0002] Such electric lighting units are well known and are usually wall or ceiling mounted. Usually such a unit comprises a casing housing a high voltage gear tray mounting one or more long-life batteries, and a fluorescent light tube in circuit with the gear and protected by a diffuser. The high voltage electrical gear is connected into the mains by a suitable lead.

[0003] The present invention is especially concerned with providing ease of access to the high voltage gear tray by a skilled electrician for servicing and battery replacement, and also access for tube replacement.and diffuser cleaning without disturbing the high voltage gear tray.

[0004] According to the present invention there is provided an electric lighting unit comprising a casing connectible to a wall or ceiling and an assembly of a high voltage gear tray, a fluorescent tube and a diffuser pivotally connected to the casing for movement between a position where the high voltage gear tray is concealed within the casing and a position where it is clear of the casing for servicing purposes and a wall of the assembly being movable to permit diffuser and fluorescent tube removal.

[0005] Preferably the assembly is secured in position in the casing by a single connection, usually a screw.

[0006] Preferably also, the diffuser and fluorescent tube can be removed by release of a single connection, usually slackening of a screw.

[0007] The casing preferably has a plurality of conduit side entry positions, say four knockouts, permitting the lighting unit to be mounted in a variety of locations and attitudes. There is preferably a punched hole configuration in the base of the casing for mounting purposes.

[0008] An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:-

Fig. 1 is a perspective vieu of an emergency electric lighting unit according to the invention showing access to the high voltage gear tray;

Fig. 2 is a perspective view of the unit showing diffuser removal; and

Fig. 3 is a detail perspective view of one end of the assembly.

[0009] The emergency electric lighting unit comprises a casing 10 and an assembly of a high voltage gear tray 11, a fluorescent tube 12 and a diffuser 13.

[0010] The casing 10 has four knockout conduit entry positions 14, three of which can be seen in/Fig.1 and the fourth in Fig. 2. In this embodiment, the unit is wall mounted and the lead connecting the high voltage gear to the mains is indicated at 15 (Fig. 2).

[0011] The assembly, as aforesaid, comprises the tray 11 which has two long side walls 16 through which the assembly is pivotally secured by screws 17 to the casing 10 (see Fig. 1). The tray 11 also has two end walls 18 and 19, which walls are flanged inwardly for the purpose of engaging around the ends of the diffuser 13 to retain same in position.

[0012] At each end, the tray 11 has terminal connections 20 for the fluorescent tube 12, which connections are in circuit with the printed circuit board of the high voltage gear, generally indicated at 21, on the other side of tray 11. The tray 11 mounts a long life battery 22 alongside the gear 21, which battery is switched into circuit, in known manner, if there is mains failure.

[0013] Normally, considering Fig. 1, the assembly seats inside the casing 10 thus concealing the printed circuit board assembly 21 and battery 22, the assembly being retained in position by a single screw 23 passing through a hole 24 in casing end wall 25 and screwing into nut insert 26 in the assembly end wall 18. Thus, for servicing and battery replacement an electrician requires only to unscrew the screw 23 and pivot the assembly outwardly (or downwardly if the unit is ceiling mounted) about screws 17.

[0014] As is mentioned above, the assembly end walls 18, 19 retain the diffuser in position. End wall 18 is stationary but end wall 19 is movable to permit diffuser removal. End wall 19 is secured by a capture screw 27 engaging in a nut insert 28 in an end flange 29 of tray 11. Slackening of the screw 27 allows its movement sufficiently away from the flange 29 to permit disengagement of the diffuser 13 from the unit for cleaning or tube replacement.

[0015] The installation of the above described emergency lighting unit is relatively simple, all mains connections being made to a fused terminal block 30 on the casing 10. Thus if any work has to be done, i.e. servicing, the electric mains is disconnected from the high voltage gear merely by removing the fuse 31 from the terminal block 30. It will be manifest that such action will also result in testing the emergency facility, i.e. mains failure simulation.

[0016] If the unit requires to be removed for bench repair the fuse 31 is removed, two transformer leads (from transformer 32) are removed and one earth lead from the terminal block 30 and then screws 17 are undone and the assembly can be taken away without disturbing any other lighting units on the same mains circuit or sub-circuit.

[0017] It will be noted that the end wall 18, 19 and side walls 16 serve to render the diffuser interior relatively dust-proof and to some extent weatharproof.

[0018] A stop is provided in the casing 10 to ensure proper alignment of the casing 10 and the assembly for insertion of the screw 23.

[0019] It is to be noted that there is a series of punched holes 33 in the base of the casing 10.

Claims

1. An electric lighting unit comprising a casing connectible to a wall or ceiling and an assembly of a high voltage gear tray, a fluorescent tube and a diffuser pivotally connected to the casing for movement between a position where the high voltage gear tray is concealed within the casing and a position where it is clear of the casing for servicing purposes and a wall of the assembly being movable to permit diffuser and fluorescent tube removal.

2. An electric lighting unit as claimed in claim 1 in which the assembly is secured in position in the casing by a single connection.

3. An electric lighting unit as claimed in claim 2, in which the single connection is a screw.

4. An electric lighting unit as claimed in any one of claims 1 to 3 in which the assembly has two flanged end walls for retaining the diffuser, one of said walls being movable to permit removal of the diffuser and access to the fluorescent tube.

5. An electric lighting unit as claimed in claim 4 in which the movable end wall is maintained in diffuser retention position by a captive screw engaging a nut insert in an end flange of the high voltage gear tray.

6. An electric lighting unit as claimed in any preceding claim in which the casing has a conduit/side entry position in at least two walls to allow the unit to be mounted in a variety of locations and attitudes.

7. An electric lighting unit as claimed in claim 8, in which the casing is provided with four knockout entry positions.

8. An electric lighting unit as claimed in any one of claims 1 to 7, in which the casing base is formed with a series of punched holes for mounting purposes.

9. An electric lighting unit, substantially as hereinbefore described with reference to the accompanying drawings.

Drawing