GB2169749A - Electrical outlet accessories with incorporated automatic circuit breaker - Google Patents

Electrical outlet accessories with incorporated automatic circuit breaker Download PDF

Info

Publication number
GB2169749A
GB2169749A GB08600704A GB8600704A GB2169749A GB 2169749 A GB2169749 A GB 2169749A GB 08600704 A GB08600704 A GB 08600704A GB 8600704 A GB8600704 A GB 8600704A GB 2169749 A GB2169749 A GB 2169749A
Authority
GB
United Kingdom
Prior art keywords
contacts
electrical outlet
mains electrical
outlet accessory
circuit protection
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB08600704A
Other versions
GB8600704D0 (en
Inventor
Stanley William Clives
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ashley Accessories Ltd
Original Assignee
Ashley Accessories Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GB858500800A external-priority patent/GB8500800D0/en
Application filed by Ashley Accessories Ltd filed Critical Ashley Accessories Ltd
Priority to GB08600704A priority Critical patent/GB2169749A/en
Publication of GB8600704D0 publication Critical patent/GB8600704D0/en
Publication of GB2169749A publication Critical patent/GB2169749A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01RELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R13/00Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
    • H01R13/66Structural association with built-in electrical component
    • H01R13/70Structural association with built-in electrical component with built-in switch
    • H01R13/713Structural association with built-in electrical component with built-in switch the switch being a safety switch
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00Contacts
    • H01H1/02Contacts characterised by the material thereof
    • H01H1/021Composite material
    • H01H1/023Composite material having a noble metal as the basic material

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Composite Materials (AREA)
  • Materials Engineering (AREA)
  • Details Of Connecting Devices For Male And Female Coupling (AREA)

Abstract

A mains electrical outlet accessory incorporating automatic circuit protection provisions has contacts which are opened by fault detection provisions. In order to employ automatic circuit protection provisions in a mains electrical outlet accessory of a resettable type, the present invention provides contacts which are of materials capable of withstanding much heavier currents, at least on a transient basis, for multiples of the normal fuse disintegration times, to allow the aforesaid contacts to be automatically opened without disintegration or welding together. Such contacts utilise a high conductivity material such as silver intimately associated with other materials having a much higher resistance to physical disintegration and/or welding together, such as tungsten, titanium oxide and molybdenum. It is also proposed to use contacts of the aforesaid materials and properties in other switched mains electrical accessories intended for use with any circuit incorporating automatic circuit protection provisions of a resettable type having the aforesaid contacts. <IMAGE>

Description

SPECIFICATION Electrical accessories with incorporated automatic circuit breaker The invention relates to mains electrical outlet accessories that have incorporated automatic circuit protection provision of a resettable type, i.e. that relay on mechanical breaking of contacts automatically in fault conditions rather than or supplementary to fuses that disintegrate at predetermined overload.
We have been engaged in a development programme for such mains electrical accessories with such incorporated circuit breaker provisions, and such programme has resulted in copending patent applications nos. 8404351 (P1119), 8430850 (P1190), 8425344 (P1238), 8411600 (P1324) and 8430852 (P1417).
Specific product development includes an electrical socket outlet accessory, and other accessories are plainly feasibly, for example of an adaptor type to fit into an existing socket accessory and afford appliance circuit connection therefrom, and spur type or permanently wired connection accessories, whether or not such are otherwise switched, even to switch accessories as such. Basic fault detection and consequent circuit breaking centres on earth leakage conditions at or above a prescribed level, usually measured in tens of milliamps, and generally indicating a served-circuit and/or appliance fault resulting effectively in current flow from live line to earth line.However, for various reasons, there are other fault conditions that we believe it can be of benefit to detect and respond to, specifically concerning the condition of the neutral line and including reversal of polarity, at least in circumstances where, as is probably inevitable for accessories hereof, they will be installed, or at least connected to, by persons not professionally trained and thus of varying skill and competence.
It is against this background that the present invention has arisen, and as our investigations have demonstrated the clear practical possibilities of occasionally encountering very high current values, actually as high as 2000 amps or more. For such heavy current fault conditions, the contact operation time of our preferred circuit breakers, typically measured in tens of milliseconds, must, of course, remain an order of magnitude greater than the disintegration time of fuses, typically five milliseconds or less for cartridge fuses, and, at least if there is no proper fuse protection, there is a consequent danger of severe damage to present-day contacts, inciuding welding in the ON state.It will be evident both that such risk of damage extends to other switch contacts in the served circuit and/or appliance and that the full extent of such danger is masked by correct fusing, i.e. as currently required in this country by regulation for consumer power circuits, generally via fused plugs. However, we take the view that risks of such dangers should be guarded against, whether arising from bridging (or absence) of fuses or wiring with wrong polarity, or whatever.
Accordingly, we now propose herein that contacts automatically opened by fault detection provisions incorporated into mains electrical outlet accessories shall be of materials capable of withstanding much heavier currents at least on a transient basis for multiples of the normal fuse disintegration times, i.e. normally for tens of milliseconds, to allow the aforesaid contacts to be automatically opened.
Thus, instead of simple copper and/or silver based or coated contact materials, we specifically propose the use of contact materials in which high conductivity material, such as silver, is intimately associated with and disseminated through other material such as tungsten, titanium oxide or molybdenum having a much higher resistance to physical disintegration and/or welding together when subject to heating by heavy current transients. Such contact materials are, of course, known in themselves for various applications outside of the specific applications proposed herein, usually in relation to switch gear for equipment that is of an inherently heavy-current operating type.As thus available or specifiable from various suppliers, those contact materials may be of sintered alloy type in which a matrix of an aforesaid other material is impregnated with silver in a proportion that is found to be suitable, in connection with which we believe that a silver content of between 25% and 75% by weight will normally apply, preferably 35% to 65%, and 50% having been found satisfactory in prototype socket outlets.
Affixing of such contacts to carriers therefore is readily achieved, for example by resistance-welding directly to such carriers or to a member otherwise affixing to such carriers, e.g. by rivetting. In either case, welding may involve a contiguous eutectic interface to the carrier or member.
It is, of course, logical for electrical accessories hereof that have a consumer's switch further to have the contacts for that switch also of materials as above proposed. In fact, for any served circuit having switching over and above the aforesaid automatic fault breaking, contacts for such switching are advantageously as above proposed. It will be appreciated that use of such contacts meets the damage possibilities of by-passed or absent fusing and wrong polarity wiring. Indeed, the absolute need for fusing is eliminated in favour of reliance on our accessories with incorporated fault break provisions.
Specific implementation of this invention will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is an outline circuit diagram; Figure 2 shows, diagrammatically, a socket outlet accessory with automatic break contacts; and Figures 3A and 3B show preferred contact affixing provisions.
Referring first to Fig. 1, a consumers mains distribution circuit, such as a ring main, is shown at 20 with live, neutral and earth lines 20L, 20N, 20E, with an exemplary outlet accessory 10 connected therein. There may, indeed will for ring main circuits, be more than one such outlet accessory 10 in the circuit 20.The accessory 10 has an incorporated fault detection and automatic contact opening provision comprising contacts 12 at least in a live line branch, a switch link 14 with contacts 16 normally closing on the contacts 12, a mechanical system 18 for breaking the contacts 12, 14 by moving the switch link 14 (usually releasing a latch to allow spring bias to move the switch link) and fault detect and mechanism drive circuitry 22 for causing such contact breaking, the conventionai reset button operated means also being indicated at 24 (usually mechanically to reengage the latch) and test button-operated means at 26 (usually to operate via the fault detect and drive circuitry 22).
It is, of course, the contacts 12 and 16 that we specifically propose herein shall be of the aforesaid contact materials. However, the outlet accessory 10 is further shown with a normal consumer-operated switch 30 also of single pole action, i.e. controlling the live line branch only via contents 32, 34. Served circuit connections 36L, 36N and 36E are shown simply exiting the accessory 10 at 38 in any suitable way, for example as an individual appliance supply cord or cable.
It is, of course, further proposed herein that the contacts 32, 34 also be of the aforesaid contact materials.
It will further be appreciated that the accessory 10 could be a socket outlet, see 40 in Fig. 2, which is a highly diagrammatic representation showing flat three-pin connection at 42 without regard to the fact that same will, of course, normally be on the uppermost face of the accessory going through the drawing, i.e. the same face as gives access to the operators for the consumers switch 30 and reset latch system 44, shown as a normally-acting rocker 46 and push button 24.
Internal connections between the socket connection 42, the switch 30 and the contacts 12, and the fault detection circuitry and test facility, are not shown. However the latter circuitry and test facility can readily be viewed as being to the left of what is shown in Fig.
2, so as to operate a solenoid 48 to drive an armature 50 in knocking a latch member 52 out of its illustrated state holding the switch link 14 to close the contacts 14, 16.
As shown, the latch member 52 is pivotted at 54 to a body 56 movable in a well 58 by the push button 24 against a first compression spring 60 acting between a seat in the body 56 and an abutment surface of the socket body about a latch entry 62 into a well 64 in which the switch link 14 can move under ledging carrying the contacts 12. The latch member 52 has an extending latch part 66 to go through a hole 68 in a switch link carrier 70, and is both biassed and centred by a second compression spring 72 acting between the switch link/carrier 14, 70 and a seating on the latch member. The whole is much as shown in our copending application no. 8425344 (P1238), i.e. the first compression spring 60 being stronger than the second 72.
Turning to Figs. 3A and 3B, contacts hereof are shown at 80 and 82 suitably secured directly to an electrically conductive carrier 84 and to a member 86 for mechanical connection to such a carrier by rivetting. Materials of the carrier 84 and member 86, such as copper or brass, generally permit resistance-welding for their securement, usually with an eutectic interface 88 or 90.
Having mentioned and shown inclusion of a consumers switch in accessories hereof, and application of contacts hereof thereto in addition to the automatic fault breaking contacts, it should be evident that this invention is similarly applicable to a switched or unswitched electrical accessory whether or not same has a specific coupling/connection to an appliance, i.e. including such as an electric light switch.
Moreover, the invention is further applicable to an adaptor for a socket outlet not itself of the type specifically described above, i.e. with the adapter affording the automatic fault break provision whether directly from the socket or as a unit on a trailing lead from a plug fitting to the socket.
In general, of course, accessories hereof are compact and of low cost compared with separate provision of fault condition circuit breaking as used to be the general rule in relation to specific appliances/equipment considered to need special protection.
It will also be appreciated that the only requirement on mechanical etc systems of the automatic resettable break mechanism is its capability of incorporation into an electrical accessory, i.e. it could be different from what is shown in Fig. 2.
Contacts hereof will, of course, withstand both fault occurrence and an attempt to remake with the faults still present.

Claims (8)

1. A mains electrical outlet accessory incorporating automatic circuit protection provisions of a resettable type having contacts which are automatically opened by fault detection provisions and wherein said contacts are of materials capable of withstanding much heavier currents, at least on a transient basis, for multiples of the normal fuse disintegration times, to allow the aforesaid contacts to be automatically opened.
2. A mains electrical outlet accessory as claimed in claim 1 in which the contacts use a high conductivity material intimately associated with and disseminated through other material having a much higher resistance to physical disintegration and/or welding together when subject to heating by heavy current transients.
3. A mains electrical outlet accessory as claimed in claim 2 in which the high conductivity material is silver.
4. A mains electrical outlet accessory as claimed in claim 2 or 3 in which said other material is tungsten, titanium oxide or molybdemum.
5. A main electrical outlet accessory as claimed in claim 2, 3 or 4 in which the contacts are of sintered alloy type in which a matrix of the aforesaid other material is impregnated with silver.
6. A mains electrical outlet accessory as claimed in claim 3 in which the silver content is in the range 25% to 75% by weight.
7. A switched mains electrical accessory for any served circuit incorporating automatic circuit protection provisions of a resettable type, wherein the switch contacts are made of the same materials as the circuit protection contacts of claims 1 to 6.
8. A mains electrical outlet accessory incorporating automatic circuit protection provisions of a resettable type constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.
GB08600704A 1985-01-12 1986-01-13 Electrical outlet accessories with incorporated automatic circuit breaker Withdrawn GB2169749A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08600704A GB2169749A (en) 1985-01-12 1986-01-13 Electrical outlet accessories with incorporated automatic circuit breaker

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB858500800A GB8500800D0 (en) 1985-01-12 1985-01-12 Electrical accessories
GB08600704A GB2169749A (en) 1985-01-12 1986-01-13 Electrical outlet accessories with incorporated automatic circuit breaker

Publications (2)

Publication Number Publication Date
GB8600704D0 GB8600704D0 (en) 1986-02-19
GB2169749A true GB2169749A (en) 1986-07-16

Family

ID=26288658

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08600704A Withdrawn GB2169749A (en) 1985-01-12 1986-01-13 Electrical outlet accessories with incorporated automatic circuit breaker

Country Status (1)

Country Link
GB (1) GB2169749A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2230146A (en) * 1989-04-07 1990-10-10 Ashley & Rock Ltd Adapters for mounting electrical outlet plates
WO1992015110A1 (en) * 1991-02-19 1992-09-03 Heinrich Kopp Gmbh & Co. Kg Protective switchgear tripped by differential current or undervoltage
WO1998019367A1 (en) * 1996-10-31 1998-05-07 Greenbrook Electrical Plc Mains electrical outlet
CN108365486A (en) * 2018-02-09 2018-08-03 夏蔓芸 One kind is exempted to pull out false-touch prevention electrical socket and its adapter

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB416683A (en) * 1932-03-23 1934-09-19 Westinghouse Electric & Mfg Co Improvements in or relating to electric circuit breakers
GB420042A (en) * 1933-04-25 1934-11-23 British Thomson Houston Co Ltd Improvements in and relating to arc extinguishing arrangements for electric circuit breakers
GB933547A (en) * 1960-03-23 1963-08-08 Ellenberger & Poensgen Overload circuit breaker for high currents
GB1141626A (en) * 1966-01-04 1969-01-29 Stackpole Carbon Co Electrical contact
GB1242004A (en) * 1967-11-13 1971-08-11 Westinghouse Electric Corp Electrical contact assembly
GB1472720A (en) * 1974-11-27 1977-05-04 Amf Inc Socket device including ground fault circuit interrupter
GB2030368A (en) * 1978-08-22 1980-04-02 Picchia Walter Del Electromagnetic Cut-out Device Used as a Relay or for Short Circuit Protection
EP0031159A1 (en) * 1979-12-21 1981-07-01 Kabushiki Kaisha Toshiba Electrical contact

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB416683A (en) * 1932-03-23 1934-09-19 Westinghouse Electric & Mfg Co Improvements in or relating to electric circuit breakers
GB420042A (en) * 1933-04-25 1934-11-23 British Thomson Houston Co Ltd Improvements in and relating to arc extinguishing arrangements for electric circuit breakers
GB933547A (en) * 1960-03-23 1963-08-08 Ellenberger & Poensgen Overload circuit breaker for high currents
GB1141626A (en) * 1966-01-04 1969-01-29 Stackpole Carbon Co Electrical contact
GB1242004A (en) * 1967-11-13 1971-08-11 Westinghouse Electric Corp Electrical contact assembly
GB1472720A (en) * 1974-11-27 1977-05-04 Amf Inc Socket device including ground fault circuit interrupter
GB2030368A (en) * 1978-08-22 1980-04-02 Picchia Walter Del Electromagnetic Cut-out Device Used as a Relay or for Short Circuit Protection
EP0031159A1 (en) * 1979-12-21 1981-07-01 Kabushiki Kaisha Toshiba Electrical contact

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2230146A (en) * 1989-04-07 1990-10-10 Ashley & Rock Ltd Adapters for mounting electrical outlet plates
WO1992015110A1 (en) * 1991-02-19 1992-09-03 Heinrich Kopp Gmbh & Co. Kg Protective switchgear tripped by differential current or undervoltage
US5347248A (en) * 1991-02-19 1994-09-13 Heinrich Kopp Ag Protective switching device for difference-current and undervoltage tripping
WO1998019367A1 (en) * 1996-10-31 1998-05-07 Greenbrook Electrical Plc Mains electrical outlet
CN108365486A (en) * 2018-02-09 2018-08-03 夏蔓芸 One kind is exempted to pull out false-touch prevention electrical socket and its adapter

Also Published As

Publication number Publication date
GB8600704D0 (en) 1986-02-19

Similar Documents

Publication Publication Date Title
US4979070A (en) Automatic reset circuit for GFCI
CA2102014C (en) Improved gfci receptacle
US5572396A (en) Electric service safety disconnect apparatus with overvoltage and overcurrent protection
US4034266A (en) Electric wall receptacle with ground fault protection
EP1005133A2 (en) Power distribution system with circuit breakers remotely resetable by signals transmitted over the power lines
GB2205700A (en) Modular electric circuit breaker apparatus
US6275044B1 (en) Arcing fault detection system
US20150194798A1 (en) Electrical fault protection device
EP0096601A1 (en) Functional low-voltage power distribution block
EP0890210B1 (en) Safety adapter for ungrounded electrical socket
US5321574A (en) Circuit breaker/surge arrestor package in which the arrestor uses an MOV that is thermally de-coupled from the breaker&#39;s thermal trip circuit
CA3012118C (en) Apparatus for isolating a network protector in an electric power distribution network
MXPA06014630A (en) Two pole circuit interrupter employing a single arc fault or ground fault trip circuit.
ATE44192T1 (en) FISH PROTECTION SWITCH|T DESIGNED AS A PLUG.
GB2169749A (en) Electrical outlet accessories with incorporated automatic circuit breaker
AU2005313826B2 (en) Master breaker device for back-up protection against electric shock in earthed user units with mains voltage dependent residual current triggering and high selectivity
KR840001584B1 (en) Wireless emergency power interrupting system for multibranch circuits
GB2128047A (en) Earth leakage monitor and earth proving apparatus
WO2012030648A2 (en) Protected power cord
GB2200001A (en) Electric cable assembly with safety device
EP0329974B1 (en) Electrical safety socket
US3544985A (en) Voltage-indicating device for a switch bushing stud
CN213752439U (en) Power socket with double-pole double-throw switch
GB2201290A (en) Earth leakage circuit breaker
GB2152775A (en) Reversed conductors auto-tripping system

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)