GB2272118A - Electrical accessory mounting - Google Patents

Abstract

There is disclosed an electrical accessory having a mounting latch member 20A, having first, pivot or hinge means 21 by which it is pivoted or hinged in a slot 11A, of the accessory and second, flange-engaging means 26 spaced from the first means by bent resilient limb means 24, 25, said second means engaging a flange 17Y of the accessory and said resilient limb means permitting a resilient change of elongation (spacing) between said first and second means sufficient to allow the second means to grip on said flange to locate the latch member in position. Second means 26 includes opposed pins riding along cam tracks 13 in the walls of the slot 11A, and in the latching position, the pins are located in portion 17Y beyond hump 18 of the cam track to hold the latching member in the latching position in which a protuberance 27 engages a mounting flange 28A. Alternatively, cut-outs 27R in the latch member may engage parts of flange 19 of the accessory body to hold the latch member in the latching position. <IMAGE>

Description

TITLE: ELECTRICAL ACCESSORY MOUNTING ETC., DESCRIPTION This invention relates to electrical accessories, and has particular application to mains-type electrical accessories and their mounting relative to accessory boxes or trunking for electrical feed wiring.

This invention arises from our development of a modular range of electrical accessories of which individual units fit onto spaced outwardly directed flanges of or as of a top-hat section DIN-rail, and normally provided by either of a busbar mains feed strip, usually an elongate holder therefor, within insulating trunking, or an inset provision of an electrical accessory box. Further details of such a system and accessories can be gained from our European Patent Applications Nos 0 453 267A and 0 462 839A, particularly for arranging stirrup-type latches by which electrical accessory bodies are attachable and detachable relative to such spaced flanges.

Whilst such stirrup-type latches are generally convenient and satisfactory in practice, it is an object of this invention to provide an alternative, generally more compact latch, whether for general application or for specific electrical accessory units where sideways accommodation required for stirrup-type latches may be impractical or not desired or simply not preferred.

According to one aspect of this invention, an electrical accessory mounting latch member has first means by which it is pivoted or hinged in a slot of the accessory concerned, and flange-engaging second means spaced from the first means by an extent including bent resilient limb means, preferably two limbs spaced transversely of the pivoting or hinging axis and serving on a resilient-return basis to permit a change of elongation between the first and second means sufficient for both of gripping flange engagement and release by flange disengagement, preferably involving traversal of a cam track, conveniently in a slot or recess of the accessory, forcing a change of elongation between flange engagement and disengagement, further preferably by varying spacing of two bent limbs from each other at their bends.

Such a latch member can be of narrow width parallel to its pivoting or hinging axis, thus conveniently and advantageously fit into or at least partially into a preferred slot-like recess extending in the height of the accessory at one end of a body part of the accessory, preferably one latch member and slot at each of opposite ends of such body part, which can be a lower body part of an above-mentioned modular range of electrical accessories.

Suitable shaping for preferred spaced limbs can be with an outward bend of at least one, preferably both, of the limbs, i.e. away from the other of the limbs, so that the second means will tend to release from flangeengagement if the one limb or both limbs is or are subjected to straightening said bend or bends. Further preferably, such release is particularly readily achieved if the latch member has an outward formation extending beyond the accessory recessing for engagement by an end of an elongate tool blade, such as of a screwdriver. Yet further preferably, such a tool blade can be used to lever against the accessory to force cam track engaging means of the latch member over preferred cam track provisions in the accessory recessing.It is particularly convenient for the outward formation to be at or near the same end of the latch member as the cam track engaging means and the second means, but be oppositely directed to the latter.

Preferred cam track provisions involve stable latch member positions at flange disengagement as well as flange engagement. However, for flange engagement, the latch member may pass through an interruption in (or even have formations that clip-fit over) accessory body formations, say bottom ribs flanking and effectively defining location relative to mounting flange positions.

Alternatives for installing latch members embodying this invention include entry from sides of the slotting/recessing having said cam track provisions, say along an upper cam track until beyond a hump defining pivoting for the latch member concerned, or entry from above and through aperturing into the slotting/recessing.

One electrical accessory in which we are interested as an available unit of our modular range is a modified version of a KLIK (Registered Trade Mark) socket, especially one rated more highly than for lighting only usage, specifically for at least 10 Amp operation. Then, and as will be further described, it is convenient, indeed considered an inventive aspect, for a lower body part to be .recessed substantially centrally of each end in order to accommodate latch members hereof, and for there to be chambers for electrical connections to one or each side of such recessing at one or both ends of the lower body part.

It is considered that an electrical accessory unit with its body part adapted to have a latch member or latch members hereof pivoted or hinged thereto constitutes another aspect of this invention, whether or not specifically a KLIK type socket or provided with latch member accommodating recessing. Snap-in securement is feasible at the pivoting or hinging provision, say by cooperating latch extension and accommodation formations at each end of the pivoting or hinging axis.

An electrical power socket of such modified KLIK type can fit within the confines of a preferred basic unit of our modular range, specifically as provided for switch units, and represent a particularly compact and useful resource of the range.

A preferred mating connector of plug type is of generally narrow elongate shape, and can conveniently be substantially cuboid. A base will normally carry connector pins extending outwardly and flex cord or cable connection terminal means inwardly, which may be in-line across the narrow width of the base, preferably for exit through one end of the connector via a flex cord or cable clamp to the same side of the connection terminal means, and further preferably through a cover fitting to the base. A fused connector is readily provided by way of a snap-in fuse -location on the base, say to one side of said connection terminal means, then preferably with the fuse-way and fuse extending towards the other end of the connector from said electrical flex cord or cable exit.A suitable cover may be hinged to the base and/or can accommodate a spare fuse, preferably as an inner clip-in cr snap-in fit, and then may be alongside the fuse-way and operative fuse of the base.

An alternative would obviously be for the spare fuse to be accommodated on the base alongside the fuse-way and operative fuse therein. Suitable hinging can be of a type where detachment occurs or can occur, say after opening to some degree beyond 900. It is further envisaged herein that aspects of invention reside in features of a connector having a hinged and/or hinged then detachable top and/or a spare fuse location free of fouling any base provision (particularly lying alongside an operative fuse and fuseway).

Specific implementation for this invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figures 1A and 1B are fragmentary section and end views of an electrical accessory body part 10 with a slotlike recess 11 and a latch member 20 shown separate and installed, respectively: Figure 2 is a sectional view showing slot-like recesses llA,B at both ends of a particular KLIK-type accessory body with separate and installed latch members 20A,B and Figures 2A,B are plan views without and with a cover part 50, respectively; Figures 3A,B,C,D are fragmentary section. end, plan, and outline operational views of an installed alternative latching member 120; Figures 4A,B,C,D are plan and sections (B-B, C-C, D-D) of a lower body part 30 of the same KLIK type socket outlet accessory:: Figure 5 is another section through the socket accessory of Figures 2 and 3, with a corresponding plug; Figures 6A,B are perspective views of a plug.

Referring first in more detail to Figures lA and 1B, each of spaced confronting faces of the recessing 11 has upper and lower cam track provisions 12 and 13 defining an upper channel 14 with a retaining hump 15 adjacent a pivot or hinge position 16, and a lower channel 17 with a hump 18 between abutments 17X,Y extending at right angles to each other. The latch member 20 has pivot ears 21 projecting to each side of one end and capable of going over the retaining hump 15 of the upper channel 14 into the pivot or hinge position 16. Limbs 22,23 of the latch member 20 are spaced and outwardly bent (away from each other) at 24,25 transversely of a pivot axis defined by the pivot ears 21.

The limbs 22,23 extend between positions of the pivot ears 21 and lower cam track engaging ears 26 projecting to each side of the latch member 20, and are capable of going over the hump 18 when the limbs are straightened sufficiently, but with resilient return to engaging either of the abutments 17X,Y. The latch member 20 extends beyond the ears 26 to oppositely directed formations 27 and 28, the former (27) as an extension to engage a flange, and the latter (28) with an indent or aperture 29 for engagement by a tool blade to aid flange disengagement.

The limbs 22,23 of the latch member 20 have resilience and the whole latch member 20 can be installed in the recess 11 as a snap-in push fit involving pushing the pivot ears 21 along the channel 14 and over the humps 15. With the lower ears 26 in the channel 14 against the abutment 19X, relaxation of straightening of the limbs 22,23 required for such installation preferably leaves those limbs at least taut (in terms of the natural shapes of their bends 24,25), feasibly at least lightly stressed (in terms of slight straightening of their bends 24,25). The latch member 20 will then be effectively captive in the recess 11 unless sufficient outward force is applied to the extension 28 to fetch the ears 26 back -clear of the abutment surface 17X.A lesser force is required for the ears 26 to go over the humps 15 in either direction of pivoting at the ears 21, thereby giving stable flange engaged and disengaged positions of the latch member 20 with the ears 26 engaging sides of the humps 18 adjacent 19X and 19Y respectively. For actual latching in the engaged position, it is satisfactory to rely on a retaining indent (for the lower ears 26) between the hump 18 and the surface 17Y. (An alternative would be for inward faces of end formations of the flange engaging part 27 to be selectively recessed (27R) to engage ends of bottom ribs 19A,B of the accessory body interrupted at the position of the latch member recessing 11).

Turning to Figures 3A,B,C,D an accessory body 110 has a slot 111 and confronting lower cam tracks 113 with humps 118 between abutments 117X,117Y (see Figure 3D). The latching member 120 has engaging ears 126 for the lower cam tracks 113, all similar to what has been described for latching member 20 and accessory body slot 11. Upper pivot ears 121 of the latching member 120 are shown larger (than for pivot ears 21 of latching member 20 and than ears 126), and rest in matching depressions 116 (see Figure 3D) in upper confronting surface formations (shown with sloped exits 112) of the slot 111 into which the latching member 120 is inserted from above between internal accessory body walls 111A,B flanking the receiving surface formations 116 and constituting an upper part of the slot 111 open at its top.The latching member 120 can be captive sideways in the slot 111 by virtue of its pivot ears 121 being unable to pass over outward slot surface formations 112 (shown below accessory body lip 120L), though the ears 126 can do so (at installation). Installation of latching members 120 could be completed by stretching its limbs 122,123 to bring the ears 126 over ends of the abutment surface 117X, but it is preferred not to require such stretching, see sloping of surfaces 117X. Inner limb 123 is shown with a more pronounced knee bend 125 than outer limb 124. A disengager formation as a hooked extension 128 can assist strength and installation.

Figure 2 repeats Figure 1A at the right hand side for recess llA and separate latch member 20A, but shows at its left hand side latch member 20B both installed in recess 11B and moved into its flange-engaging position, both in relation to what is actually a lower body part 30 of KLIKtype socket of power-handling rating; see also Figure 4 for detail of locating engagement of bottom ribbing 19, shown web-braced at 19W, and chamfer-edged flanging 48A,B.

Figures 4A-D show more detail of the body part 30, including chambers 32A,34A to each side of its recessing 11A. There are also chambers 32B,34B at the other end of the body 30 flanking the recessing 11B. All but chamber 34B are shown with wire entry holes (36L,N,E) through accessory end walls of the chamber concerned, for three-wire (live, neutral and earth) mains feeds connecting to chamber-housed electrical connector blocks, see dashed plan outlines 40L,N,E and full line side detail 40L, having contact provisions, see dashed plan outlines 42L,N,E and full side details 42L,E in Fig 2A.

For KLIK socket units and corresponding plug units, the live and neutral socket contacts 42L,N go to spaced resilient limbs that curve towards each other to grip free limbs 44L,N of spaced L-shaped blade-like plug pins 46L,N; and the earth socket contact 42E is of folded resilient plate type to be compressed in engaging cross-head 47E of T-shaped earth plug pin 46E. Corresponding entries in a socket cover part 50 are simple spaced slots 52L,N and rectangular opening 52E giving access to key-hole shaped aperture 53E in part 60 (see below), the former (52L,N) spaced towards the latter from the actual live and neutral contacts (42L,N) and shielded by at least the cover part 50, so that live and neutral electrical connections can only be made after plug pin entry into the socket and linear sliding of the plug over the socket.

For the particular preferred KLIK socket, the chambers 32A,B and 34A,B of the lower body part 30 are open-topped for easy loose installation of the connector blocks 40L,N,E and associated electrical contacts 42L,N,E. Such block etc installation is followed by securement to the lower body part 10 of an upper body part 60 that will take the cover part 50, preferably as a snap-fit thereto, and cover the connector blocks and contacts save for apertures registering with heads of clamp screws shown for making connections to mains wires bared and passed through the holes 36L,N,E.

For KLIK sockets, it is particularly preferred that such upper body part 60 extend over at least the live and neutral electrical contacts 42L,N. However, the upper body part 60 will, of course, have provision for entry of plug contact pins through the cover part 50 prior to sliding the plug over the socket in order to make neutral electrical coupling between the plug and the socket.

For the particular KLIK-socket shown, the upper body part 60 has an indent or well 61 with walls to each of the chambers 32,34 and plug pin entries through those walls to the chambers 32A,B for live and neutral connector blocks 40L,N. The indent or well 61 affords operative accommodation for physical blocking and shielding provisions for the first entries for plug pins through the cover part 50, and such provisions are seen as having inventive merit in themselves, particularly in being operative without registration of plug pin entries and socket contacts and other than in and relying upon the direction of movement of the plug pins directly into the socket contacts (both as is normal).

A shutter 62 is rockable in the indent or well 61 and has a bias spring 63 operative relative to abutment 64 for over-centre action relative to shutter rocking and latching against spring-resisted sliding out of socket 'entry blocking location (say by cooperating projecting and indented provisions of the shutter 62 and the well 61, respectively), unless and until the shutter 62 is moved and held by plug pins in a position intermediate its overcentre latched positions (see end upstands 67L,N for engagement by L-shaped blade-like plug pins 44L,N). Snapfit for the cover part 50 promotes both easy assembly and ready access for the shutter 62 and its bias spring 64, as well as access to terminal connection screws.

As normal for KLIK type units, the socket has a further keyhole aperture for mechanical connection also by a T-shaped plug projection (resembling the earth entry/pin provisions, though without electrical connections in a three-wire system).

The particular KLIK plug shown at 70 has transversely aligned cord or flex wire connectors 71L,N,E each with associated shielded connection provisions to related plug pins 46L,N,E and a live-side fuse holder provision 72 shown to the opposite side of the linear bank of connectors 71 from end cord or cable entry 73 and clamping provision 74.

A preferred hinged plug cover 75 has the cord or flex entry 73 and is shown capable of being screwed down at 76 to the base. The plug cover 70 may come wholly off the base after hinging through a prescribed angle, and further preferably has an internal holder 77 for a spare fuse 78 that can conveniently lie either alongside the active fuse 79 when the cover is closed down onto the base, or above the active fuse 79 (as actually shown).

Claims (3)

1. An electrical accessory having a mounting latch member having first, pivot or hinge means by which it is pivoted or hinged in a slot of the accessory and second, flange-engaging means spaced from the first means by bent resilient limb means, said second means engaging a flange of the accessory and said resilient limb means permitting a resilient change of elongation (spacing) between said first and second means sufficient to allow the second means to grip on said flange to locate the latch member in position.

2. An accessory according to claim 1, in which the flange comprises a cam track for the second member and has a retaining hump for the second means to grip on.

3. An accessory according to claim 1 or claim 2, of which the latch member comprises two bent arms arranged as a parallelogram.