EP1137030A1 - Electric switching unit for security means in household appliances - Google Patents

Electric switching unit for security means in household appliances Download PDF

Info

Publication number
EP1137030A1
EP1137030A1 EP01106430A EP01106430A EP1137030A1 EP 1137030 A1 EP1137030 A1 EP 1137030A1 EP 01106430 A EP01106430 A EP 01106430A EP 01106430 A EP01106430 A EP 01106430A EP 1137030 A1 EP1137030 A1 EP 1137030A1
Authority
EP
European Patent Office
Prior art keywords
bimetal strip
spring
strip
ptc resistor
switching unit
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.)
Granted
Application number
EP01106430A
Other languages
German (de)
French (fr)
Other versions
EP1137030B1 (en
Inventor
Oton Leban
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.)
Illinois Tool Works Inc
Original Assignee
Metalflex Druzba Za Proizvodnjo Industrijske Opreme d o o
ITW Appliance Components doo
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 Metalflex Druzba Za Proizvodnjo Industrijske Opreme d o o, ITW Appliance Components doo filed Critical Metalflex Druzba Za Proizvodnjo Industrijske Opreme d o o
Publication of EP1137030A1 publication Critical patent/EP1137030A1/en
Application granted granted Critical
Publication of EP1137030B1 publication Critical patent/EP1137030B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H37/00—Thermally-actuated switches
    • H01H37/02—Details
    • H01H37/10—Compensation for variation of ambient temperature or pressure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H61/00—Electrothermal relays
    • H01H61/06—Self-interrupters, i.e. with periodic or other repetitive opening and closing of contacts

Definitions

  • the invention concerns an electric switching unit for a security means in household appliances, wherein a PTC resistor is inserted between a bistable switching spring, whereto a security means blocking element is attached, and a bimetal strip and wherein, at a possible elevated temperature of the appliance, the PTC resistor displacement towards the bistable switching spring as accomplished by the bimetal strip is compensated for in a more precise manner.
  • the applicant manufactures a security means for use in household appliances. It is provided with a suitable electric switching unit.
  • This unit comprises a PTC resistor, a bimetal strip connected to a first connecting terminal of the unit, a compensating bimetal strip and a bistable switching spring, which is connected to a second connecting terminal of the unit.
  • the bistable switching spring is composed of a strip spring and a hoop spring, which at one end are rigidly joined to each other and fastened to a casing of the electric switching unit, whereas, close to the free end, they are elastically joined by a coupling spring.
  • the PTC resistor is inserted between the bimetal strip and the strip spring, the position of which is decisive for the jumping over of the hoop spring from one stable position into another one, and it has an electric contact with both of them.
  • a security means blocking element is inclinably mounted to the free end of the hoop spring.
  • the ends of the bimetal strip are leaned against the ends of the compensating bimetal strip which compensates for the PTC resistor displacement due to the elevated appliance temperature,
  • the proximity of the compensating bimetal strip to the PTC resistor and a good thermal contact therewith through both ends of the bimetal strip result in the compensating bimetal strip being too strongly influenced by the PTC resistor temperature, which overshadows the influence of the appliance temperture.
  • the technical problem to be solved by the present invention is how to improve the sensing of the appliance temperature by means of a compensating bimetal strip so that by a properly placing it with respect to a bimetal strip the influence of the temperature of a PTC resistor supported by the bimetal strip is reduced.
  • An electric switching unit and provided for a security means in household appliances is represented in the Figure in sectional view. It comprises a PTC resistor 1, a bimetal strip 2 connected to a first connecting terminal of the electric switching unit, a compensating bimetal strip 21 and a bistable switching spring 3, which is connected to a second connecting terminal of the electric switching unit.
  • the bistable switching spring 3 is made up of a strip spring 31 and a hoop spring 32.
  • the springs 31 and 32 are rigidly joined to each other at one end and fastened to a casing of the electric switching unit, whereas, close to the free end they are elastically joined by a coupling spring 33.
  • the hoop spring 32 of the bistable switching spring 3 jumps over from one stable position into another one.
  • the PTC resistor 1 is inserted between the bimetal strip 2, preferentially in the middle of the bimetal strip 2, and the strip spring 31, the position of which is decisive for the jumping over of the bistable switching spring 3.
  • the PTC resistor 1 has an electric contact with the bimetal strip 2 and also with the hoop spring 32 through a contact 311 mounted thereon.
  • a security means blocking element 4 is inclinably mounted to the free end of the hoop spring 32, which is provided with a movable contact 321 close to said free end.
  • a first end of the bimetal strip 2 is leaned against an adjusting screw 22 and the second end thereof is leaned against the compensating bimetal strip 21, preferentially in the middle of the compensating bimetal strip 21, both ends of which are leaned against the casing of the electric switching unit.
  • the electric current tlows through the PTC resistor 1 warming it up.
  • the bimetal strip 2 which is in touch with the PTC resistor 1, gets warm too and pushes the PTC resistor 1 towards the strip spring 31.
  • the strip spring 31 undergoes a certain displacement, the hoop spring 32 jumps over into another stable position and the blocking element 4 is moved in direction 41 to a blocking position.
  • the compensating bimetal strip 21 compensates for the said displacement for a contribution resulting from the elevated appliance temperature. Therefore the PTC resistor 1 should only slightly influence the temperature of the compensating bimetal strip 21. Namely, the compensating bimetal strip 21 must sense the temperature of the appliance wherein the security means is placed. This is accomplished by the length of the bimetal strip 2 sufficiently exceeding the diameter of the PTC resistor 1 so that the warmed up PTC resistor 1 does not exert too Strong influence upon the compensating bimetal strip 21.

Landscapes

  • Thermally Actuated Switches (AREA)
  • Thermistors And Varistors (AREA)
  • Fire-Detection Mechanisms (AREA)

Abstract

Electric switching unit for a security means in household appliances comprises a PTC resistor (1), a bimetal strip (2), a bimetal strip (21) compensating for an elevated appliance temperature and a bistable switching spring (3), which is made of a strip spring (31) and a hoop spring (32) coupled to each other by a coupling spring (33). The PTC resistor (1) is placed in a electrically conductive way between the strip spring (31) decisive for the jumping over of the hoop spring (32) and the bimetal strip (2). A first end of the bimetal strip (2) is leaned against an adjusting screw (22) and the second end thereof is leaned against the compensating bimetal strip (21) supported at both ends. The length of the bimetal strip (2) is such that the PTC resistor (1) only slightty influences the temperature of the compensating bimetal strip (21).

Description

  • The invention concerns an electric switching unit for a security means in household appliances, wherein a PTC resistor is inserted between a bistable switching spring, whereto a security means blocking element is attached, and a bimetal strip and wherein, at a possible elevated temperature of the appliance, the PTC resistor displacement towards the bistable switching spring as accomplished by the bimetal strip is compensated for in a more precise manner.
  • The applicant manufactures a security means for use in household appliances. It is provided with a suitable electric switching unit. This unit comprises a PTC resistor, a bimetal strip connected to a first connecting terminal of the unit, a compensating bimetal strip and a bistable switching spring, which is connected to a second connecting terminal of the unit. The bistable switching spring is composed of a strip spring and a hoop spring, which at one end are rigidly joined to each other and fastened to a casing of the electric switching unit, whereas, close to the free end, they are elastically joined by a coupling spring. The PTC resistor is inserted between the bimetal strip and the strip spring, the position of which is decisive for the jumping over of the hoop spring from one stable position into another one, and it has an electric contact with both of them. A security means blocking element is inclinably mounted to the free end of the hoop spring. The ends of the bimetal strip are leaned against the ends of the compensating bimetal strip which compensates for the PTC resistor displacement due to the elevated appliance temperature, The proximity of the compensating bimetal strip to the PTC resistor and a good thermal contact therewith through both ends of the bimetal strip result in the compensating bimetal strip being too strongly influenced by the PTC resistor temperature, which overshadows the influence of the appliance temperture.
  • Consequently, the technical problem to be solved by the present invention is how to improve the sensing of the appliance temperature by means of a compensating bimetal strip so that by a properly placing it with respect to a bimetal strip the influence of the temperature of a PTC resistor supported by the bimetal strip is reduced.
  • The novel features that are considered characteristic of this invention are set forth with particularity in the appended claims.
  • The advantage of the electric switching unit for a security means in household appliances with respect to such known electric switching unit exists in that therein a more precise compensation for the elevated appliance temperature is accomplished, which favourably results in a shorter turning-off time of the security means and also its spread is narrower.
  • The invention will now be explained in more detail by way of the description of an embodiment and with reference to the accompanying drawing representing in the sole Figure a section of a preferential embodiment of the electric switching unit for a security means in household appliances.
  • An electric switching unit according to the invention and provided for a security means in household appliances is represented in the Figure in sectional view. It comprises a PTC resistor 1, a bimetal strip 2 connected to a first connecting terminal of the electric switching unit, a compensating bimetal strip 21 and a bistable switching spring 3, which is connected to a second connecting terminal of the electric switching unit.
  • The bistable switching spring 3 is made up of a strip spring 31 and a hoop spring 32. The springs 31 and 32 are rigidly joined to each other at one end and fastened to a casing of the electric switching unit, whereas, close to the free end they are elastically joined by a coupling spring 33. Depending on the position of the strip spring 31, the hoop spring 32 of the bistable switching spring 3 jumps over from one stable position into another one.
  • The PTC resistor 1 is inserted between the bimetal strip 2, preferentially in the middle of the bimetal strip 2, and the strip spring 31, the position of which is decisive for the jumping over of the bistable switching spring 3. The PTC resistor 1 has an electric contact with the bimetal strip 2 and also with the hoop spring 32 through a contact 311 mounted thereon.
  • In a known way a security means blocking element 4 is inclinably mounted to the free end of the hoop spring 32, which is provided with a movable contact 321 close to said free end.
  • A first end of the bimetal strip 2 is leaned against an adjusting screw 22 and the second end thereof is leaned against the compensating bimetal strip 21, preferentially in the middle of the compensating bimetal strip 21, both ends of which are leaned against the casing of the electric switching unit.
  • When voltage is applied to the connecting terminals of the electric switching unit according to the invention, the electric current tlows through the PTC resistor 1 warming it up. The bimetal strip 2, which is in touch with the PTC resistor 1, gets warm too and pushes the PTC resistor 1 towards the strip spring 31. When the strip spring 31 undergoes a certain displacement, the hoop spring 32 jumps over into another stable position and the blocking element 4 is moved in direction 41 to a blocking position.
  • The compensating bimetal strip 21 compensates for the said displacement for a contribution resulting from the elevated appliance temperature. Therefore the PTC resistor 1 should only slightly influence the temperature of the compensating bimetal strip 21. Namely, the compensating bimetal strip 21 must sense the temperature of the appliance wherein the security means is placed. This is accomplished by the length of the bimetal strip 2 sufficiently exceeding the diameter of the PTC resistor 1 so that the warmed up PTC resistor 1 does not exert too Strong influence upon the compensating bimetal strip 21.

Claims (3)

  1. Electric switching unit for a security means in household appliances, comprising a PTC resistor (1), a bimetal strip (2) connected to a first connecting terminal of the unit, a compensating bimetal strip (21) and a bistable switching spring (3), which is connected to a second connecting terminal of the unit and whereto a blocking element (4) is attached and between a part (31) of the bistable switching spring (3) decisive for its jumping over and the bimetal strip (2) the PTC resistor (1) is placed, which has an electric contact with said part (31) as well with the bimetal strip (2), characterized in that a first end of the bimetal strip (2) is leaned against an adjusting screw (22) and the second end thereof is leaned against the compensating bimetal strip (21).
  2. Electric switching unit for a security means in household appliances as recited in claim 1, characterized in that the PTC resistor (1) is placed in the middle of the bimetal strip (2)
    and that the second end of the bimetal strip (2) is leaned against the middle of the compensating bimetal strip (21) which is supported at both ends.
  3. Electric switching unit for a security means in household appliances as recited in claim 1 or 2, characterized in that the length of the bimetal strip (2) exceeds the diameter of the PTC resistor (1) to such an extent that the PTC resistor (1) only slightly influences the temperature of the compensating bimetal strip (21).
EP20010106430 2000-03-23 2001-03-22 Electric switching unit for security means in household appliances Expired - Lifetime EP1137030B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SI200000081 2000-03-23
SI200000081A SI20537A (en) 2000-03-23 2000-03-23 Electric switching assembly for security device preparation within an appliance

Publications (2)

Publication Number Publication Date
EP1137030A1 true EP1137030A1 (en) 2001-09-26
EP1137030B1 EP1137030B1 (en) 2003-02-19

Family

ID=20432627

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20010106430 Expired - Lifetime EP1137030B1 (en) 2000-03-23 2001-03-22 Electric switching unit for security means in household appliances

Country Status (4)

Country Link
EP (1) EP1137030B1 (en)
DE (1) DE60100104T2 (en)
ES (1) ES2192550T3 (en)
SI (1) SI20537A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1550759A2 (en) * 2003-12-18 2005-07-06 ITW Metalflex d.o.o. Tolmin Security means in a household appliance
EP1645706A2 (en) * 2004-10-06 2006-04-12 ITW Metalflex d.o.o. Tolmin Safety lock of a door of household appliances
WO2006095241A1 (en) 2005-03-08 2006-09-14 Itw Metalflex, Druzba Za Proizvodnjo Delov Za Gospodinjske Aparate, D.O.O. Blocking device for the door of an electric household appliance, in particular the door of a washing machine
WO2008044132A3 (en) * 2006-10-13 2008-08-21 Itw Metalflex Druzba Za Proizv Blocking device for the door of an electric household appliance, in particular the door of a washing machine
WO2013151964A1 (en) 2012-04-03 2013-10-10 Illinois Tool Works Inc. Door locking device with integrated door sensing switch

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110106668B (en) * 2019-06-11 2021-06-15 温州天健电器有限公司 Electric door lock on-off control device, door lock and washing machine

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3702454A (en) * 1971-09-24 1972-11-07 Montec Corp Ambient compensated time delay switch
EP0682352A2 (en) * 1994-05-12 1995-11-15 SAMUEL MONTAGU & CO. LIMITED (as Security Trustee of DIAMOND H CONTROLS LIMITED) Energy regulator

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3702454A (en) * 1971-09-24 1972-11-07 Montec Corp Ambient compensated time delay switch
EP0682352A2 (en) * 1994-05-12 1995-11-15 SAMUEL MONTAGU & CO. LIMITED (as Security Trustee of DIAMOND H CONTROLS LIMITED) Energy regulator

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1550759A2 (en) * 2003-12-18 2005-07-06 ITW Metalflex d.o.o. Tolmin Security means in a household appliance
EP1550759A3 (en) * 2003-12-18 2009-08-26 ITW Metalflex d.o.o. Tolmin Security means in a household appliance
EP1645706A2 (en) * 2004-10-06 2006-04-12 ITW Metalflex d.o.o. Tolmin Safety lock of a door of household appliances
EP1645706A3 (en) * 2004-10-06 2008-04-02 ITW Metalflex d.o.o. Tolmin Safety lock of a door of household appliances
WO2006095241A1 (en) 2005-03-08 2006-09-14 Itw Metalflex, Druzba Za Proizvodnjo Delov Za Gospodinjske Aparate, D.O.O. Blocking device for the door of an electric household appliance, in particular the door of a washing machine
WO2008044132A3 (en) * 2006-10-13 2008-08-21 Itw Metalflex Druzba Za Proizv Blocking device for the door of an electric household appliance, in particular the door of a washing machine
WO2013151964A1 (en) 2012-04-03 2013-10-10 Illinois Tool Works Inc. Door locking device with integrated door sensing switch

Also Published As

Publication number Publication date
DE60100104D1 (en) 2003-03-27
ES2192550T3 (en) 2003-10-16
DE60100104T2 (en) 2004-01-29
SI20537A (en) 2001-10-31
EP1137030B1 (en) 2003-02-19

Similar Documents

Publication Publication Date Title
US4399423A (en) Miniature electric circuit protector
US5367279A (en) Overcurrent protection device
US4476452A (en) Motor protector
US4092573A (en) Motor starting and protecting apparatus
US5294852A (en) Thermally protected electric motor
CN101197480B (en) Plug
US4958254A (en) Five pin protector module for telephone circuits
USRE31367E (en) Motor starting and protecting apparatus
US4394646A (en) Temperature indicator for a glass ceramic cooking surface
EP1137030B1 (en) Electric switching unit for security means in household appliances
JPH03211316A (en) Electric cigarette lighter
GB1594334A (en) Thermal protection for electric motors
RU97101166A (en) TUBULAR ELECTRIC RESISTIVE ELEMENT, HEATING PLATE AND ELECTRIC KETTLE
EP0684623B1 (en) Appliances having resistive elements and thermal protective apparatus used therewith
US4591820A (en) Thermostatic electric switch and thermal biasing assembly therefor
GB2098436A (en) Electrical heating element
JP2001508969A (en) Positive thermistor device
US4646051A (en) Thermostatic electric switch and thermal biasing assembly therefor
WO2012014025A1 (en) Improved electronic and electromechanical thermostat
US4754251A (en) Thermostatic electric switch and thermal biasing assembly therefor
AU2011201313A1 (en) Surface mount thermostat
US6097275A (en) Motor starting and protecting apparatus
GB2251986A (en) Switched electrical contacts for cordless appliances
JPS62165824A (en) Thermostat
US6525640B1 (en) Resistive thermostat for electrical motors protection

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

Kind code of ref document: A1

Designated state(s): DE ES GB IT

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

17P Request for examination filed

Effective date: 20020228

AKX Designation fees paid

Free format text: DE ES GB IT

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): DE ES GB IT

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 60100104

Country of ref document: DE

Date of ref document: 20030327

Kind code of ref document: P

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: ILLINOIS TOOL WORKS INC.

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2192550

Country of ref document: ES

Kind code of ref document: T3

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

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

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20031120

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20130327

Year of fee payment: 13

Ref country code: ES

Payment date: 20130326

Year of fee payment: 13

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20140322

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20140322

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20150427

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20140323

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20200323

Year of fee payment: 20

Ref country code: DE

Payment date: 20200327

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 60100104

Country of ref document: DE