EP0134718A2 - Composants électriques comprenant un dispositif sensible à la température - Google Patents

Composants électriques comprenant un dispositif sensible à la température Download PDF

Info

Publication number
EP0134718A2
EP0134718A2 EP19840305980 EP84305980A EP0134718A2 EP 0134718 A2 EP0134718 A2 EP 0134718A2 EP 19840305980 EP19840305980 EP 19840305980 EP 84305980 A EP84305980 A EP 84305980A EP 0134718 A2 EP0134718 A2 EP 0134718A2
Authority
EP
European Patent Office
Prior art keywords
heat
electrical component
sleeve
plastics material
responsive device
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Withdrawn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
EP19840305980
Other languages
German (de)
English (en)
Inventor
Kenneth Samuel James
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.)
Dubilier PLC
Original Assignee
Dubilier PLC
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
Application filed by Dubilier PLC filed Critical Dubilier PLC
Publication of EP0134718A2 publication Critical patent/EP0134718A2/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
    • H01T1/00—Details of spark gaps
    • H01T1/14—Means structurally associated with spark gap for protecting it against overload or for disconnecting it in case of failure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H37/00—Thermally-actuated switches
    • H01H37/02—Details
    • H01H37/32—Thermally-sensitive members
    • H01H37/46—Thermally-sensitive members actuated due to expansion or contraction of a solid
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H37/00—Thermally-actuated switches
    • H01H37/74—Switches in which only the opening movement or only the closing movement of a contact is effected by heating or cooling

Definitions

  • the present invention relates to electrical components incorporating a temperature responsive device and more particularly to such components in which the temperature responsive device is provided to perform a protective function on the component or on an associated component.
  • the temperature responsive device may take the form of a bimetallic member which, when heated, is subjected to distortion which in turn can be employed to perform an open-circuiting or short-circuiting function.
  • the temperature responsive device are relatively expensive and require careful adjustment.
  • Another form of temperature responsive device comprises a resilient electrically conductive member which is normally maintained in a stressed condition by means including a heat softenable material, the arrangement being such that when the heat softenable material becomes soft at an elevated temperature, the stress in the resilient electrically conductive member is released to enable it to perform a short-circuiting or open-circuiting function.
  • the heat softenable material may be a metallic fusible material, for examle a relatively low melting point alloy, or a fusible insulating material such as a thermoplastics material which becomes soft at a desired temperature.
  • the device employs a fusible insulating material which normally holds the stressed resilient electrically conductive member out of engagement with a cooperating contact
  • the heat softening of the insulating material allows the resilient electrically conductive member to engage the contact
  • a film of the softened insulating material remains interposed between the engaging parts thereby preventing the protective short-circuiting function from occuring.
  • the invention provides an electrical component comprising a temperature responsive device including a member of plastics material having a heat responsive memory and which is formed so as to shrink longitudinally on the application of heat.
  • the invention provides an electrical component having at least two electrodes or regions which either become short-circuited or open-circuited when a temperature responsive device associated with the component responds to an increase in temperature and wherein the short-circuiting or open-circuiting function is controlled by a member of plastics material having a heat responsive memory and which is formed so as to shrink longitudinally on the application of heat.
  • the invention may particularly be employed as an overheating protection device attached to a component such as an excess voltage arrestor which may take the form of a pair of spaced electrodes defining a spark gap and arranged in a gas filled enclosure.
  • a component such as an excess voltage arrestor which may take the form of a pair of spaced electrodes defining a spark gap and arranged in a gas filled enclosure.
  • Such arrestors may also take the form of three electrode devices in which case the third electrode is generally located in the region of the spark gap.
  • the temperature responsive device comprises a length of a stiff resilient metal wire which is surrounded over at least part of its length by a sleeve of an insulating plastics material having a heat responsive memory characteristic such that on the application of heat it will shrink in the lengthwise direction.
  • This shrinkage of the sleeve in the lengthwise direction may either result in one or more regions of the wire being exposed to perform a short-circuiting function, or alternatively result in one or more exposed regions of the wire being covered by the insulating plastics sleeve to perform an open-circuiting function.
  • a member of insulating plastics material having a heat responsive memory may be arranged as a separator between two parts, at least one of which is resiliently urged towards the other and the application of heat causes the member of insulating plastics material to shrink lengthwise sufficiently to allow the two parts to come into contact and thereby perform a short-circuiting function.
  • plastics materials are available which have a heat responsive memory.
  • Preferred materials for use in the present invention include irradiated polyolefins and modified polyvinylidene fluorides.
  • Figure 1 shows a simple form of temperature responsive device in which a wire 1 of spring temper, for example a plated spring steel wire or a beryllium copper wire, is located within a sleeve 2 of heat shrinkable material, that is to say a plastics material having a heat responsive memory.
  • the sleeve 2 has a cut-out or notch 3 at the mid point of its length so that the wire 1 is exposed and may make contact with a conductor such as the centre terminal pin of a three electrode excess voltage arrestor.
  • Figure 2 is a plan view of the casing of such a three electrode excess voltage arrestor comprising two electrodes defining a spark gap and having terminal pins 5 and an intermediate electrode having a terminal pin 4.
  • Figure 3 is an elevation of the same device. The arrestor is fitted with a temperature responsive device as shown in Figure 1, and as can be seen in Figure 2, the cut-out or notch 3 permits electrical contact between the centre pin 4 and the spring temper wire 1 whilst the sleeve 2 insulates the end pins 5 from the spring temper wire. The exposed wire may be attached to the pin 4 or merely rest against it.
  • Figure 4 is a plan view of the same component after a sustained excess voltage has been applied to the arrestor resulting in overheating. It can be seen that the sleeve 2 has retracted or shrunk longitudinally under the effect of heat and electrical contact has now been made between the spring temper wire 1 and the end pins 5. The amount of shrinkage may be up to about 50% of the length of the sleeve. Since the end and centre pins are now electrically connected one to the other, the discharge through the arrestor is stopped and no further heating can occur. Also because the terminals are so connected together, an item of equipment fitted with the arrestor is still protected against damage due to overvoltage or excess voltage surges.
  • Figure 5 illustrates an embodiment of surge arrestor which is not fitted with pins and the centre of the spring temper wire is welded at 6 direct to the centre electrode 7 of the arrestor.
  • the extremities of the wire 1 are performed at la such that they are biassed into contact with the end electrodes 8 but are normally electrically isolated from them by the sleeve 2.
  • the wire contacts the electrodes 8 and shorts them together with the electrode 7.
  • FIG. 6 The principle of the invention, namely employing a heat shrinkable sleeve which shrinks longitudinally on the application of heat may be extended to other types of excess voltage arrestors, as for example is illustrated in Figure 6.
  • a gas discharge tube 10 is welded between two terminal plates 11, and ceramic spacers 12 are also provided between the plates.
  • One of the spacers encloses a compression spring 9 which carries a heat shrinkable sleeve 2a normally shrouding the ends of the spring.
  • the spring may be reverse wound over part of its length to anchor the sleeve at an intermediate point.
  • FIG. 7 is a plan view of a component 13 having a temperature responsive device arranged so that a normal connection is broken or open-circuited in response to overheating.
  • the temperature responsive device again comprises a spring tension wire 14 enclosed in a sleeve 2 of heat shrinkable plastics material which in this case has three cut-outs or notches 15 arranged opposite contact pins 16, by virtue of which all three pins are normally interconnected.
  • the sleeve will retract longitudinally causing the two outer cut-outs or notches to move from the vicinity of the pins, and leave a portion of the insulating sleeving interposed between the wire and the pins so that the circuit is opened.
  • the invention Whilst the invention has been specifically described, in the main, as applied to excess voltage arrestors, it may obviously be applied to any other electrical component in order to protect it from damage due to overheating.
  • the component e.g. of Figure 7 could be an integrated circuit or microchip.
  • the temperature responsive device could itself be formed as a separate component which is mounted in the vicinity of and appropriately connected to a component or components which it is to protect from overheating.

Landscapes

  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Fuses (AREA)
  • Thermally Actuated Switches (AREA)
EP19840305980 1983-09-09 1984-08-31 Composants électriques comprenant un dispositif sensible à la température Withdrawn EP0134718A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8324174 1983-09-09
GB838324174A GB8324174D0 (en) 1983-09-09 1983-09-09 Electrical components

Publications (1)

Publication Number Publication Date
EP0134718A2 true EP0134718A2 (fr) 1985-03-20

Family

ID=10548532

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19840305980 Withdrawn EP0134718A2 (fr) 1983-09-09 1984-08-31 Composants électriques comprenant un dispositif sensible à la température

Country Status (3)

Country Link
EP (1) EP0134718A2 (fr)
JP (1) JPS6074370A (fr)
GB (2) GB8324174D0 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0603428A1 (fr) * 1992-12-24 1994-06-29 Cerberus Ag Dérivateur de surtensions, rempli de gaz
WO1998034308A1 (fr) * 1997-01-31 1998-08-06 Siemens Aktiengesellschaft Dispositif de protection contre les surtensions rempli de gaz et dote de deux electrodes en forme de godets

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0227694U (fr) * 1988-08-10 1990-02-22
US6223071B1 (en) 1998-05-01 2001-04-24 Dusa Pharmaceuticals Inc. Illuminator for photodynamic therapy and diagnosis which produces substantially uniform intensity visible light

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL6714664A (fr) * 1966-11-03 1968-05-06
NL153733B (nl) * 1966-11-03 1977-06-15 Raychem Corp Verbindingsorgaan voorzien van een krimphuls voor het maken van een mechanische en/of elektrische verbinding.

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0603428A1 (fr) * 1992-12-24 1994-06-29 Cerberus Ag Dérivateur de surtensions, rempli de gaz
WO1998034308A1 (fr) * 1997-01-31 1998-08-06 Siemens Aktiengesellschaft Dispositif de protection contre les surtensions rempli de gaz et dote de deux electrodes en forme de godets

Also Published As

Publication number Publication date
GB8422066D0 (en) 1984-10-03
JPS6074370A (ja) 1985-04-26
GB8324174D0 (en) 1983-10-12
GB2146490A (en) 1985-04-17

Similar Documents

Publication Publication Date Title
US4262317A (en) Line protector for a communications circuit
US6795290B2 (en) Surge arrestor
US4047143A (en) Fused resistive electrical protection device
CA2060641C (fr) Limitateur de tension
US4876621A (en) Line protector for a communications circuit
GB2222023A (en) Arrester apparatus
US3896343A (en) Heat-operated short-circuiting arrangements
US4723190A (en) Safety device communication equipment
US5844761A (en) Device for circuit board power surge protection such as protection of telecommunication line cards from lightning and power cross conditions
US3281625A (en) Over-voltage protection techniques
US4733325A (en) Electrical protective devices
US5027100A (en) Gas tube fail safe device for telephone protector modules
US5488535A (en) Arc suppressor for sidactors
US4717902A (en) Electrical components incorporating a temperature responsive device
US4458288A (en) Electrical protective devices
US4434449A (en) Protector unit for telecommunications circuits
EP0134718A2 (fr) Composants électriques comprenant un dispositif sensible à la température
US4910489A (en) Gas tube fail-safe device for telephone protector modules
CA2051564C (fr) Boite de derivation a fonction de protection contre la surtension
US4237515A (en) Protective electrical discharge device
EP0657978B1 (fr) Dispositif à sûreté intégrée pour utilisation dans un dérivateur de surtensions
US5831808A (en) Lightning arrester device
US4583954A (en) Methods of assembling electrical protective devices
EP0471006B1 (fr) Dispositif de tube a gaz a securite integree destine aux modules de protection de telephones
US5475356A (en) Gas-tube arrester

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT BE CH DE FR IT LI LU NL SE

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19861018

RIN1 Information on inventor provided before grant (corrected)

Inventor name: JAMES, KENNETH SAMUEL