GB2244605A - Electrical trunking - Google Patents

Abstract

Trunking, for housing electrical equipment, comprises an open faced U-shaped duct 10 closable by a cover plate 11 hinged thereto. The cover plate 11 may incorporate an electrical socket 13. When in the closed relationship the cover plate 11 and duct 10 define a channel 17 which underlies the exposed surfaces of the cover plate 11 and an adjacent portion of the duct 10. Rectangular slidable locking elements 24 are located in the channel 17. Each locking element 24 is slidable between a position A whereby it bridges the duct 10 and the cover plate 11 to lock them together and a position B where it is clear of the cover plate 11 to allow it to open relative to the duct 10. <IMAGE>

Description

CABLE TRUNKING The present invention relates to trunking especially but not exclusively for housing electrical equipment.

Trunking for housing electrical equipment is well known, generally comprising an elongate open duct of U-shaped cross-section closed by a cover plate fixed thereto by various means for example screwing or snap fit. The cover plates need to be easy to fit and to remove to allow service or maintenance work to be effected with minimum disruption to the trunking system. This applies in particular to access points in the trunking such as sockets for plugs.

Once fitted the cover plates must be secure and robust enough to meet safety criteria and to remain in place. In the particular case of socket cover plates in a trunking system, the withdrawal of a plug from a socket must not result in the cover plate working or being pulled free from the duct.

In the case of known snap fit cover plates, for example, the withdrawal of a plug often results in the separation of the cover plate from the duct.

With such trunking arrangements space is at a premium and the cover plate securing or locking arrangement must be simple and compact.

It is an object of the present invention to provide a simple but effective cover plate securing or locking arrangement which is easy to apply and release but which resists accidental cover plate separation from the duct of the trunking during normal usage.

In accordance with the present invention there is provided trunking, especially but not exclusively for housing electrical equipment, the trunking comprising an open-faced duct closable by an openable cover plate, the duct and cover plate, when in closed assembled relationship, defining a channel bridging the cover plate and an adjacent portion of the duct and underlying the exposed surfaces thereof and a locking element slidable within the channel between a first position wherein it bridges the duct portion and the cover plate to lock the latter relative to the duct and a second position where it is clear of the cover plate to permit opening of the latter relative to the duct.

As a result of this invention there is provided trunking which achieves the aforesaid object and which additionally, unlike existing trunking, does not have any visible screw or other fastener fixings.

Preferably the channel is accessible externally of the closed duct and cover plate assembly such that an actuator can be inserted into said channel portion to slide the locking element between said first and second positions.

Preferably said locking element is of rectangular configuration and defines a bow along its length to provide sliding friction within said channel.

Preferably said cover plate is in a hinged relationship with said duct.

Preferably there are provided in said trunking separate electric socket cover plates lockable in the manner defined in the preceding four paragraphs and wherein the socket cover plates define apertures in which pins of an electric plug can be received.

Also according to the invention there is provided, a method for locking a cover plate to an open-faced duct, the method comprising the step of sliding a locking element in a channel portion defined between said cover plate and said duct and underlying exposed surfaces thereof between a first position wherein said locking element bridges the channel to lock the cover plate to the duct and a second position where it is clear of said cover plate to permit opening of the latter relative to the duct.

Preferably said duct houses electrical equipment.

Preferably an actuator is insertable into said channel to engage with said locking element to slide it within said channel between said first and second positions.

It will be appreciated that the term "trunking" as used herein is not to be restricted to housings for electrical equipment but rather is intended to cover all arrangements in which a lid or cover plate closes an open-faced container body with a channel parallel to exposed surfaces thereof being defined therebetween.

A specific embodiment of the present invention will now be described, by way of example, with reference to the drawings in which: Fig. 1 is a fragmentary exploded view of trunking for electrical equipment in accordance with this invention; Fig. 2 is an end view of the trunking; and Fig. 3 is a plan view of the trunking.

The trunking comprises an elongate duct 10 of substantially U-shaped cross-section and is adapted to receive and house electric cables or wires. The duct 10 is closable by substantially flat cover plates 11. At predetermined positions along the trunking length, electrical socket cover plates 12, which again are substantially flat, are fitted. Each socket cover plate 12 defines apertures 13 designed to receive the pins of an electrical plug (not shown).

The interior of the duct 10 has walls defining channels 14 adapted to receive cables (not shown) and to hold them in place within the duct 10 (see Fig. 2).

One side wall 10A of the duct 10 at the open face thereof has an inturned flange 15 with a lower integral stepped flange 16 defining a channel 17 therebetween.

The other side wall 10B of the duct 10 at the open face thereof also has an inturned flange 18 which inboard of the side wall 10B defines a U-shaped formation 19 open to the open face of the duct 10 and terminating in a bead 19A.

One edge of the cover plate 11 or 12 is formed with a depending lip 20 adapted to engage and rest on the stepped flange 16, the lip 20 defining with the main body of the cover plate 11 or 12 a channel 21 which, when the cover plate 11 or 12 is in position on the duct 10, is aligned with the channel 17.

The adjacent edges of the flange 16 and the cover plate 11 or 12 define a slit 22 for a purpose hereinafter described.

Each cover plate 11 or 12 at its opposed edge has an underlying socket formation 23 adapted to cooperate with the bead 19A to form a hinge for the cover plate 11 or 12.

When the cover plates 11 and 12 are assembled on the duct 10 there is therefore provided along one side thereof an underlying channel 17,21 which can be accessed through the slit 22.

It is to be understood that both sides of the trunking can be formed with this channel/slit arrangement, i.e. no hinge at one side of the trunking.

It is also to be understood that the cover plates can be hinged or otherwise secured to one side only of the duct in any conventional or other manner.

Locking elements 24 are provided releasably to hold the cover plates 11,12 closed relative to the duct 10.

A convenient form of locking element 24 comprises an open rectangular element whereof the long sides are bowed but may simply be a flat strip of plastics material for example.

The locking element 24 is dimensioned to bridge channels 17 and 21 and to be slidable therealong, the bowing provided a light frictional resistance to the sliding motion to ensure that there is retention of the locking element in adjusted position.

Reference is made to Fig. 3, where operation of the locking elements 24 is illustrated.

The socket cover plate 13 is shown with two locking elements 24 at positions A, these locking elements 24, in these positions, securing the socket cover plate 13 against removal from the duct 10 and resisting accidental pull-out by removal of an engaged electrical plug (not shown).

To access the duct 10 underneath the socket cover plate 13 the locking elements 24 are slid clear of same to positions B.

Movement of the locking elements between positions A and B can easily be effected by a thin-bladed tool or other thin element such as a card for example being inserted through the slit 22 to contact an end of the locking element 24 to push same from position A to position B or vice versa.

The present invention thus provides a simple but effective, easily released securing or locking arrangement between the duct and its cover plates.

Claims (10)

1. Trunking comprising an open-faced duct closable by an openable cover plate, the duct and cover plate when in closed assembled relationship defining a channel bridging the cover plate and an adjacent portion of the duct and underlying the exposed surfaces thereof, and a locking element slidable within the channel between a first position wherein it bridges the duct portion and the cover plate to lock the latter relative to the duct and a second position where it is clear of the cover plate to permit opening of the latter relative to the duct.

2. Trunking according to claim 1, wherein the channel is accessible externally of the closed duct and cover plate assembly such that an actuator can be inserted into said channel portion to slide the locking element between said first and second positions.

3. Trunking according to claim 1 or 2 wherein the locking element is of rectangular configuration and defines a bow along its length to provide sliding friction within said channel.

4. Trunking according to any preceding claim wherein said cover plate is in a hinged relationship with said duct.

5. Trunking according to any preceding claim wherein the duct houses electrical equipment.

6. Trunking according to any preceding claim wherein said cover plates incorporate separate electric sockets each socket having apertures in which pins of an electric plug can be received.

7. A method for locking a cover plate to an open-faced duct, the method comprising the step of sliding a locking element in a channel portion defined between said cover plate and said duct and underlying exposed surfaces thereof between a first position wherein said locking element bridges the channel to lock the cover plate to the duct and a second position where it is clear of said cover plate to permit opening of the latter relative to the duct.

8. A method according to claim 7 wherein said channel is accessible externally of said closed duct and cover plate assembly and an actuator is insert able into said channel portion to engage with the locking element to slide it within said channel between said first and second positions.

9. Trunking substantially as hereinbefore described with reference to the accompanying drawings.

10. A method for locking a cover plate to an open faced duct substantially as hereinbefore described with reference to the accompanying drawings.