NZ205975A - Clip-on circuit breakers with slide-in termination - Google Patents

Description

205975 Priority Oate(s): ff?. .

Complete Specification Filed: . ^ Class: H?A $//?*,./^J Publication Date: P.O. Journal, No: ...

I „ 14 OCT 1985, Patents Form No. 5 Patents Act 1953 COMPLETE SPECIFICATION "ELECTRICAL WIRING DISTRIBUTION SYSTEM" WE, SIEMENS LTD. a corporation of the State of Victoria, of 544 Church Street, Richmond, Victoria 3121, Australia, hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: V \ - r - v' : "* ., ■'*' / •■■• v- ..... . ...

I 1 «gj 205975 Electrical wiring distribution system.

The invention relates to an electrical wiring distribution system in which wiring devices, e.g. circuit protection switches, are held in lined-up arrangement and may be connected to a supply system which is, as a rule, a multiphase system, by a mounting foot of each respective wiring device being held on a holding means having a flat U profile with edges projecting laterally from its sides and the electrical terminals of the wiring devices each being connected to a 10 respective connecting lead of the supply system.

Electrical wiring distribution systems branch an incoming supply system off into various load circuits which may be protected by circuit breakers. Auxiliary devices such as earth leakage circuit breakers or manually operated main switches which facilitate manual zero current switching of following branches independent of the circuit breaker, contact making clocks and other wiring devices may be accommodated in such distribution systems. Conventional wiring devices have a mounting foot which, as viewed from above, forms a recess which 20 can be essentially regarded as a flat, inverted U. Projections or resilient noses may be arranged on the sides of the U to facilitate snap-action fitting of the wiring device onto a carrier rail in the form of a flat U with edges projecting laterally from its sides. Such wiring devices can be snap-fitted from above onto a carrier rail and lined up one alongside the other. A connecting lead of the supply system may be attached to one terminal and the load-side outgoing lead to another terminal. In such systems wiring devices may only be fitted or replaced as a rule by specialist personnel. 30 It has been deemed advantageous to construct wiring 205975 distribution systems in which wiring devices may be fitted and replaced in the live state, even by non-specialist personnel.

It is an object of the invention to provide an electrical wiring distribution system in which wiring devices may be replaced even in the live state without any danger to persons.

According to the present invention there is disclosed an electrical wiring distribution system for connecting a plurality of manually operable wiring devices in the form of circuit breakers or the like, to bus bars of a power supply system, said wiring distribution system comprising a carrier having said wiring devices arranged and held in a row or rows by engagement between a corresponding one of a plurality of guide tongues projecting transversely from said carrier and a corresponding holding meand included in a mounting foot of each said wiring device, said carrier having a plurality of rigid connection leads each connected to a respective one of said bus bars and each electrically insulated by said carrier in the direction of manual operation of said wiring devices except for a corresponding tool guide aperture wherein each said holding means has a width in the row direction substantially the same as the width in the row direction of one of said wiring devices or an integral multiple thereof, and comprises a substantially U-shaped member engageable-with the mounting foot of the corresponding wiring device,/'havTrig- a, /'V 'SAPliB87«i Jr.; s"~ ■ I - airjbf aligned apertures shaped V to slidingly receive the corresponding guide tongue, and having retaining means to maintain said guide tongue and holding means so engaged, and wherein a corresponding one of said connection leads bears against a respective electrical terminal of each said wiring device, and each said terminal is manipulatable by a tool passing through the corresponding tool guide aperture to engage or disengage each said connection lead with each said terminal whereby each said wiring device is releasably secured in said distribution system by both interengagement of the corresponding respective electric terminal and connection lead and interengagement of the corresponding guide tongue and holding means so that release of any said wiring device from said distribution system disconnects same from said power supply system.

In a solution known per se, L-shaped sides are provided on a carrier plate, the former having an inverted L profile, a flank of the mounting foot of a wiring device engaging behind the sides thereof. Otherwise the wiring device is only held by the electrical connection, whereby a rigid connecting lead holds down the wiring device and fixes 205975 it in the mounting position. Connection rails are here preferably laid across the wiring devices, said connection rails not being insulated from the operating plane during mounting (GB-PS 1 554 614) .

It is also known in the prior art that means for attachment of busbars may also be provided on a carrier plate for wiring devices (US-PS 3 309 581) . In this case the elect-.rical contact is obtained at the bottom of the mounting base which, in association with mating contacts of the distribution system, provides electrical contact as also a clamp hold. In this case the wiring devices are only njechanically held in the zone of the electical contact. A hooked-in corner of the wiring device outside the zone of electrical contact cannot provide a secure mechanical hold.

In the wiring distribution system according to the preferred embodiment of the invention it is of particular advantage, without mentioning the electrical insulation of the terminal of the wiring devices from the operating plane, that the wiring devices are disposed and held in a mechanically secure manner and are only fixed in the mounting position through the electrical connections without being subjected to considerable tensile forces, whereas if a wiring device has to be removed from the mounting position it is automatically isolated from the supply system.

In a simple construction, the carrier means is the base for a housing accomodating busbars, said housing projecting with integral collars over the electrical connection points of the wiring devices. The embodiment of the housing accommodating the busbars may be in the manner of a duct closed by a cover formed by the laterally projecting collars. ^ f Duct and cover of the housing accommodating busbars 205975 are, for purposes of storage and mounting, preferably in the form of line-up section each having a width equal to an integral multiple of device unit width.

A construction which is economical in manufacture and compact in its final state is obtained by the tongues being formed on both sides of a back in the manner of a comb and being attached at least to strip-shaped carriers with this back, said s€rip-shaped carriers being spaced at least in the mounting zone for wiring devices by cranking and forming attachment means for the distribution system.

If the collars have guide- penetrations for tools over the electrical connection points for the wiring devices, a wiring device can be connected to live busbars of the distribution system with conventional insulated tools, such as screwdrivers, without danger to personnel. On the one hand, the terminal of the wiring device is protected against random contact and on the other hand, the tool is prevented from slipping sideways onto other live parts.

The invention is to be described in greater detail with the use of an example of twc embodiments shown in rough schematic representation in the drawings in which: Fig. 1 shows the essential part of the wiring distribution system in side view, whereby a wiring device is just being mounted on one side. For the sake of clarity a conventional distribution system housing in which the represented essential part may be disposed has been omitted.

Fig. 2 shows a wiring device, in this embodiment a single-pole circuit breaker, in the non-operative position with itsjjlmechanical and electrical connection parts for the wiring distribution system in an exploded view. 305975 Fig. 3 shows the wiring distribution system, corresponding to Fig. 1, however without fitted wiring devices, and Fig. 4 shows the essential part of the wiring distribution system, corresponding to Fig. 3, in a sectional elevation. Figs. 5 to 8 are described hereafter.

The central part of an electrical wiring distribution system corresponding to Fig. 1 may be imagined in a conventional housing of a wiring distribution system. It can hold wiring devices 1, e.g. circuit protection switches, in lined-up arrangement and facilitate connection to a supply system which is, as a rule, a multiphase system.' The busbars with the three phases are arranged as supply bars 2 in a housing 3 which is preferably so constructed that it can stand up to forces acting on the busbars. The mounting foot 4 of the wiring device 1 is held on a holding means 5 with flat U profile and edges projecting laterally from its sides. For this purpose the wiring devices may be provided with projecting noses and/or resilient, nubs in sides of the mounting foot 4. The electrical terminals 7 of the wiring devices 1 are, in the mounted state, connected to one respective connection lead 12 of the supply system, the busbars 2.

The holding means 5 has approximately the width of a wiring device in the line-up direction of the wiring devices 1. It has in its sides recesses or apertures 9 which are in alignment with each other and can be slid onto guide tongues 10, as may be seen from Fig. 2. Such guide tongues 10 are formed on a carrier means 11 of the distribution system. A rigid connection lead 12 presumed to be electrically insulated from the operating plane bears against and is clamped against one Respective electrical terminal 7 of the wiring devices 1 when 305975 in the mounted state.

The carrier means 11, c.f. Figs. 1, 3 and 4 is the base of a housing 3 accomodating a busbar 2. The housing projects with integral i collars 14 over the electrical connection points, in the present embodiment the terminals 7 of the wiring devices 1, and effectively insulates them (by seperation) against inadvertent contact from above by a hand used to operate the manual operating element or switch 15.

In the embodiment corresponding to Figs. 3 and 4 the housing 3 accommodating the busbars 2 is in the form of a duct closed by a cover 15A. The cover also forms the laterally projecting collar 14.

The duct trough 16 and cover lEAof the housing 3 accommodating the busbars 2 are, in the embodiment corresponding to Figs. 3 and 4, capable of being lined-up and have a width equal to an integral multiple of a division unit. The term "division unit" is understood to mean the width of the narrowest wiring device when wider wiring devices have a width which is an integral multiple thereof.

The tongues 10 in the embodiment are formed on both sides of the base in the manner of a comb, as may be best seen from Fig. 3. The base 11 can be attached at least to strip-shaped carriers 18 which are cranked to provide spacing at least in the mounting zone for the wiring devices and form attachment means 19.

The collars 14 over the electrical connection points, the terminals 7 of the wiring devices, preferably have guide penetrations 20 for tools, corresponding to Fig. 3.

The busbars 2 can be connected at projecting ends corresponding to Fig. 3 to the supply system through terminals 21. Branches are run off from the busbars 2 within the terminal 8 can then be disconnected in the zero current state. The holding means 5 can then be withdrawn. Wiring devices with snap-action holding can be released through a tilting motion when slightly slid off from the respective guide tongue the holding means 5 subsequently being completely withdrawn from the guide tongue 10.

A further emboidment of the present invention will now be described with reference to the following additional drawings:- Fig. 5 is a view similar to Fig. 2 of one further embodiment; Fig. 6 is a longitudinal cross-sectional view through the holding means 5; Fig. 7 is a view similar to Fig. 2 of an additional further embodiment; and Fig. 8 is a view similar to that of Fig. 6 but of the arrangement of Fig. 7.

It will be apparent that although the carrier means 11 is normally mounted upright in a vertical plane so that the holding means 5 are normally retained on the guide tongues 10 without difficulty, in some cases it may be desirable to mount the carrier means 11 extending in a horizontal direction Under these circumstances the holding means 5 positioned on those ones of the guide tongues 10 which are downwardly directed, would slide from the guide tongues 10. Thus it is desirable to provide an attachment means to retain the holding means 5 in position after it has been slid onto the corresponding guide tongue 10. This is also a desirable attribute when the carrier means is to be manipulated after the holding means 5 have been located on the guide tongues 10.

In accordance with one embodiment of the present invention the above described retaining means are realised by forming the holding means 5 with an arched base 30 as seen in Fig. 5. As best seen in Fig. 6, the arched base 30 and recesses 9 co-operate to form a frictional clamp which retains the holding means 5 in position after the holding means 5 has been slid onto the guide tongue 10.

An alternative embodiment is illustrated in Figs. 7 and 8. Here the retaining means takes the form of a protrusion 31 formed in the base of the holding means 5 and co-operable with an aperture 32 in the guide tongue 10. As seen in Fig. 8 when the holding means is slid into its intended position, the protrusion 31 is located within the aperture 32 thus preventing the movement of the holding means 5 from the guide tongue 10 without the application of a substantial manual withdrawal force.

The foregoing describes only some embodiments of the present invention and modifications, obvious to those skilled in the art, may be made thereto without departing from the scope of the present invention. 203975 In accordance with one embodiment of the present invention the above described retaining means are realised by forming the holding means 5 with an arched base 30 as seen in Fig. 5. As best seen in Fig. 6, the arched base 30 and recesses or. aperture 9 co-operate to form a frictional clamp which retains the holding means 5 in position after the holding means 5 has been slid onto the guide tongue .10.

An alternative embodiment is illustrated in Figs. 7 and 8. Here the retaining means takes the form of a protrusion 31 formed in the base of the holding means 5 and co-operable with an aperture 32 in the guide tongu$ 10. As seen in Fig. 8 when the holding means is slid into its intended position, the protrusion 31 is located within the aperture 32 thus preventing the movement of the holding means 5 from the guide tongue 10 without the application of a substantial manual withdrawal force.

The foregoing describes only some embodiments of the present invention and modifications, obvious to those skilled in the art, may be made thereto without departing from the scope of the present invention.

Vv-' © 205975 m

Claims (10)

WHAT WE CLAIM IS:

1. An electrical wiring distribution system for connecting a plurality of manually operable wiring devices in the form of circuit breakers or the like, to bus bars of a power supply system, said wiring distribution system comprising a carrier having said wiring devices arranged and held in a row or rows by engagement between a corresponding one of a plurality of guide tongues projecting transversely from said carrier and a corresponding holding meand included in a mounting foot of each said wiring device, said carrier having a plurality of rigid connection leads each connected to a respective one of said bus bars and each electrically insulated by said carrier in the direction of manual operation of said wiring devices except for a corresponding tool guide aperture wherein each said holding means has a width in the row direction substantially the same as the width in the row direction of one of said wiring devices or an integral multiple thereof, and comprises a substantially U-shaped member engageable with the mounting foot of the corresponding wiring device, having a pair of aligned apertures shaped to slidingly receive the corresponding guide tongue, and having retaining means to maintain said guide tongue and holding means so engaged, and wherein a corresponding one of said connection leads bears against a respective electrical terminal of each said wiring device, and each said terminal is manipu1atab1e by a tool passing through the correspondafig tool ^tiide |berture to engage or disengage each *Tt" "8^°/?/957S -12- ' / •Xjx i 2'»5975 m said connection lead with each said terminal whereby each said wiring device is releasably secured in said distribution system by both interengagement of the corresponding respective electric terminal and connection lead and interengagement of the corresponding guide tongue and holding means so that release of any said wiring device from said distribution system disconnects same from said power supply system.

2. An electrical wiring distribution system as claimed in claim 1 wherein said U-shaped member has aligned, oppositely directed projections extending therefrom at either end, said projections being slidingly engageable with the mounting foot of the corresponding wiring device in a direction substantially perpendicular to the direction of sliding engagement between said member and the corresponding guide tongue.

3. An electrical wiring distribution system according to claim 1 or 2, characterised in that the carrier comprises the base of a housing accommodating said busbars, said housing having laterally projecting integrally formed collars which extend over said respective electrical terminals of the wiring devices.

4. An electrical wiring distribution system according to claim 3 wherein said tool guide apertures are in said collars.

5. An electrical wiring distribution system according to piaim 3 or 4 characterised in that the housing acqoinmoda^sfeB^toe busbars is formed in the manner of -13- o 2"5375 a' a duct closed by a cover, the side edges of said cover forming said laterally projecting collars.

6. An electrical wiring distribution system according to claim 5 characterised in that the duct trough and cover of the housing accommodating the busbars are formed in sections each having a width equal to an integral multiple of a division unit and being capable of being longitudinally aligned to form said carrier.

7. An electrical wiring distribution system according to any one of claims 1 to 5, characterised in that the guide tongues are formed in the manner of the teeth of a comb and lie to both sides of a back, at least two strip-shaped carriers are attached to said back and are cranked to provide spacing at least adjacent the wiring devices between said back and a support surface upon which said back is mounted.

8. An electrical wiring system as claimed in any one of the preceding claims, wherein said retaining means comprises an arched base on said U-shaped member, said arched base forming a frictional fit with said corresponding guide tongue when said guide tongue and holding means are slidingly engaged.

9. An electrical wiring system as claimed in any one of claims 1 to 7, wherein said retaining means comprises a protrusion on the base of said U-shaped member engageable with an- aperture in the corresponding guide tongue when said guide tongue and holding means are slidingly engaged.

10. An electrical-.wiring system substantially as 1' 205975 described with reference to Figs. 1,3 and 4 and any of Fig. 2 or Figs. 5 and 6 or Figs. 7 and 8 of the drawings. Lii£shc3f. By>4fs7thelr authorised Agents., A. J. PARK & SON. " ilkl >r " 6 MAR 1987n -15-