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EP0809270A2 - Mécanisme commutateur à contact de ressort réversible et relais thermique de surcharge - Google Patents

Mécanisme commutateur à contact de ressort réversible et relais thermique de surcharge Download PDF

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Publication number
EP0809270A2
EP0809270A2 EP97108306A EP97108306A EP0809270A2 EP 0809270 A2 EP0809270 A2 EP 0809270A2 EP 97108306 A EP97108306 A EP 97108306A EP 97108306 A EP97108306 A EP 97108306A EP 0809270 A2 EP0809270 A2 EP 0809270A2
Authority
EP
European Patent Office
Prior art keywords
spring
reversing
plate spring
contact
central leg
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Withdrawn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
EP97108306A
Other languages
German (de)
English (en)
Other versions
EP0809270A3 (fr
Inventor
Kenji Suzuki
Yukinari Furuhata
Shoji Yokoyama
Katsumi Akiike
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.)
Fuji Electric Co Ltd
Original Assignee
Fuji Electric Co 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
Application filed by Fuji Electric Co Ltd filed Critical Fuji Electric Co Ltd
Publication of EP0809270A2 publication Critical patent/EP0809270A2/fr
Publication of EP0809270A3 publication Critical patent/EP0809270A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H73/00—Protective overload circuit-breaking switches in which excess current opens the contacts by automatic release of mechanical energy stored by previous operation of a hand reset mechanism
    • H01H73/02—Details
    • H01H73/04—Contacts
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H5/00—Snap-action arrangements, i.e. in which during a single opening operation or a single closing operation energy is first stored and then released to produce or assist the contact movement
    • H01H5/04—Energy stored by deformation of elastic members
    • H01H5/18—Energy stored by deformation of elastic members by flexing of blade springs
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10—Operating or release mechanisms
    • H01H2071/109—Operating or release mechanisms with provisions for selecting between automatic or manual reset

Definitions

  • the present invention relates to a reversing spring contact switching mechanism for opening and closing a contact using a reversing spring mechanism that responds to the operation of a releasing lever, and a thermal overload relay comprising a combination of the reversing spring contact switching mechanism and a trigger element that responds to an overload current.
  • an electromagnetic contactor connected to a feeding circuit for an electric motor includes a thermal overload relay such as that described above for protecting the device from overloads.
  • FIG. 4 illustrates a thermal overload relay using a conventional reversing spring contact switching mechanism which is disclosed in JP-A-2-86024.
  • 1 designates a resin case for a relay, in which a bimetal heat element 2 which responds to overload current in a main circuit (e.g. power circuit of a motor), a reversing spring mechanism 3, and a contact mechanism 4 are incorporated.
  • a main circuit e.g. power circuit of a motor
  • a reversing spring mechanism 3 e.g. power circuit of a motor
  • the bimetal heat element 2 which forms a trigger element includes a bimetal 2a wrapped with a heater wire 2b through which the load current from the main circuit passes, wherein one end of a shifter 2c coupled to the tip of the bimetal 2a is disposed opposite to a first end of a seesaw-like releasing lever 5 (only one bimetal heat element 2 is shown in the figure, but for a multi-phase circuit there will be one such element for each phase).
  • the reversing spring mechanism 3 is assembled from multiple parts. More particularly, the reversing spring mechanism 3 comprises a reversing plate spring 3a made of a thin metallic spring material and formed, as shown in Figures 5(a) and (b), using a punch-press or similar working process; a reversing drive spring 3b made of a metallic plate spring material, flexed to a "U"-like shape and engaged with the plate spring 3a; and a mounting substrate 3c.
  • the drive spring 3b has a slit-like engagement hole at both ends thereof, and is locked and fixed between the tip of a central leg piece 3d protruding into a window in the plate spring 3a and a claw at the opposite window end.
  • An engagement piece 3e formed on the mounting substrate 3c is fitted into a receiving groove 1a formed in the resin case 1 and rollably supported using as a supporting point the tip of the engagement piece 3e.
  • the tip of the plate spring 3a is fitted and coupled to a contact mechanism 4 described below.
  • the plate spring 3a is positioned so that the second end of the releasing lever 5 is opposite the central leg piece 3d.
  • Reference numeral 3f designates an adjustment screw for an operation point
  • 3g designates a compression spring for pressing and holding the plate spring 3a within the case.
  • the contact mechanism 4 has a normally closed contact 4a, 11 and a normally open contact 4b, 12.
  • Each of the contacts comprises a fixed contact piece 11, 12 and a movable contact piece.
  • the movable contact pieces 4a, 4b are incorporated in a slider 4c, which is supported so as to slide in the resin case 1.
  • the tip of the plate spring 3a is inserted into a slot opened at one end of the slider 4c to interconnect the spring 3a with the slider 4c.
  • Reference numeral 4d designates a resetting push button.
  • the resetting push button 4d may be pressed to move the slider 4c of the contact mechanism 4 to the right, thereby causing the reversing spring mechanism 3 to return to its initial state and reset the relay.
  • the conventional reversing contact switching mechanism incorporated in the thermal overload relay, in particular, the reversing spring mechanism 3 for driving the contacts, has certain disadvantageous operational and assembling characteristics. That is, in the conventional reversing spring mechanism 3, the drive spring 3b flexed like a "U” is engaged and coupled with the plate spring 3a. Thus, when the reversing spring mechanism 3 is reversed, sliding friction between metallic members occurs at fitting engagement points A and B (see Fig. 5(a) and (b)), which are between the plate spring 3a and both ends of the drive spring 3b, thereby causing the reversing point of the relay to vary and the operational characteristics of the overload relay to become unstable.
  • the reversing spring mechanism 3 comprises the plate spring 3a and the drive spring 3b.
  • the plate spring or the drive spring 3b must be flexed while both ends are coupled to the engagement claws of the plate spring 3a. This assembly step is cumbersome. Consequently, automatic assembly using robots is very difficult and assembly requires manual work.
  • Another object of the invention is to provide a thermal overload relay comprising a combination of the reversing spring contact switching mechanism and a bimetal heat element that can respond to an overload current.
  • the reversing spring mechanism comprises a singlespring part, thereby eliminating the need of a cumbersome assembly process for assembling two parts together as in conventional techniques, reducing the number of required parts, and enabling the mechanism to be automatically assembled into products without the need for manual work.
  • the single spring part namely a reversing plate spring has no portion that is subjected to friction during a reversing operation and no part that is buckled during such an operation, thereby making the reversing point more stable than that in conventional reversing spring mechanisms.
  • This reversing spring contact switching mechanism can be applied to various contact relays that use a snap action to open and close a contact, or applied to contact switching mechanisms for switches.
  • three bimetal heat elements 2 are the same as the conventional one shown in Figure 4.
  • a shifter 2c is coupled to the free end of the three bimetals 2a each including a heater wire 2b and corresponding to a respective phase of a three-phase main circuit.
  • the heat elements 2 are opposed to a temperature compensation bimetal 5a coupled to a seesaw-like releasing lever 5 at the tip of the shifter 2c.
  • a reversing spring contact switching mechanism 6 which is linked with the heat elements 2 via the releasing lever 5 comprises an assembly of a reversing plate spring 7, the detailed structure of which is described below; first and second supporting arms 8, 9 for supporting the plate spring 7; a contact piece 4a directly formed on the plate spring 7, which is used as a movable contact piece and forms a normally closed contact together with a fixed contact piece 11; another movable contact piece 4b disposed separately from the plate spring 7, which forms a normally open contact together with a fixed contact piece 12; an L-shaped contact drive lever 10 with one end coupled to the plate spring 7 and its tip opposite the contact piece 4b; and a releasing lever 5 such as the one described above.
  • the plate spring 7 comprises a single thin plate member in which three leg pieces consisting of a lateral pair of outer leg pieces 7a and a central leg piece 7b that is longer than the outer leg pieces (three-prong fork shape) are formed by a process such as a punch-press process from a thin plate, and in which a bent tension spring section 7c is formed in a V shape in the intermediate portion of the central leg piece 7b, as shown in Figures 2(a) and (b).
  • the spring section 7c has a larger width D than the width d of the central leg piece 7b.
  • the three leg pieces are connected at one end to a connecting base 7e.
  • the free ends or tips of the outer leg pieces 7a are formed like the edge of a knife.
  • a frame-like engagement section 7d with a window 7d-1 opened therein is formed at the free end or tip of the central leg piece 7b, and the lower inner edge of the window 7d-1 is machined so that it is as sharp as the tips of the outer leg pieces 7a.
  • at least the outer side edges of the right and left outer leg pieces are folded into an "L"-like shape to form reinforcement ribs 7a-1 as shown in the figure, and thereby increasing the rigidity of the outer leg pieces 7a.
  • the plate spring 7 in this embodiment is used as a movable contact, and the contact piece 4a is coupled, by thermal caulking for example, to the connecting base 7e coupling the outer leg pieces 7a and the central leg piece 7b together.
  • the plate spring 7 is reversibly engaged and supported between the first and second arms 8 and 9 as shown in Figure 3.
  • the tip edge of each outer leg 7a is engaged with and fixed to a respective V-shaped groove section 8a in the first supporting arm 8 as a hinge for a rolling supporting point.
  • the supporting arm is U-shaped, one groove section 8a is provided in each of the lateral arm portions of the U-shape and the central leg piece 7b extends in between these two arm portions.
  • the window 7d-1 in the engagement section 7d at the tip of the central leg piece is caught in a V-shaped engagement groove 9a formed in the second supporting arm 9, and is engaged and fixed in a position displaced longitudinally (i.e., substantially vertically in Figure 1) relative to the supporting points at the tips of the outer leg pieces 7a.
  • a plurality of grooves 9a are formed in the supporting arm 9 like sawteeth to permit adjustment of the engagement position of the central leg piece 7b along the horizontal direction of the arm.
  • the plurality of adjustment grooves 9a formed in the second supporting arm 9 can be used to adjust the reversing point of the plate spring 7 on the second supporting arm or compensate for assembly errors and tolerances with respect to relative placement of the bimetal 2a of the heat element 2, the shifter 2c, and the releasing lever 5.
  • the plate spring 7 When the plate spring 7 is installed between the first and second supporting arms 8 and 9, the plate spring 7 has two stable positions, namely where the spring tension of the spring section 7c is equivalent to the spring drag of the leg pieces. In its stable positions the plate spring 7 is inclined to the right and left, respectively, relative to a plane including the supporting points on the first supporting arm 8 and the second supporting arm 9.
  • the movable contact 4a is fixed to the plate spring 7 and in the stationary state shown in Figure 1(a) a certain contact pressure between the contact pieces 4a and 11 is required.
  • the position of the plate spring 7 in this stationary state should not be one of the stable positions mentioned above but a position in which the spring force of the spring section 7c is greater than the spring drag of the leg pieces and an equilibrium exists between the spring force of the spring section 7c, the spring drag of the leg pieces and the reaction force of the fixed contact piece 11.
  • the plate spring 7, the first supporting arm 8, the second supporting arm 9, the movable contact piece 4b, the releasing leve 5 and the contact drive lever 10 may be assembled as a complete unit in advance; therefore, the assembly of the reversing plate spring mechanism 6 can be easily installed in the case of a device such as the thermal overload relay.
  • the spring section 7c can be formed to have a large width to reduce stress, thereby preventing the spring force from being reduced due to creep, thereby increasing the service life of the device.
  • thermal overload relay comprising a combination of the reversing spring contact switching mechanism 6 with the heat elements 2 is described with reference to Figures 1(a) and (b).
  • the bimetals 2a of the heat elements 2 assume the position shown by the solid line and the releasing lever 5 is almost free of any contact with central leg piece 7b.
  • the plate spring 7 is inclined upward to the right by the spring force of the spring section 7c using the tip edges of the leg pieces 7a as rolling supporting points or pivots, thereby closing the normally closed contact 4a, 11 and opening the normally open contact 4b, 12.
  • the shifter 2c When an overcurrent flows through a main circuit (for example, a feeding circuit for an electric motor) and significantly bends the bimetals 2a as shown by the broken lines in the figure, the shifter 2c is substantially displaced in the direction shown by arrow P to press and rotate the releasing lever 5 counterclockwise.
  • the releasing lever 5 has an upper end and a lower end and is pivotally supported between the two ends. The counter-clockwise rotation of the releasing lever 5 causes the tip of its upper end to press against the central leg piece 7b of the plate spring 7.
  • the normally closed contact 4a, 11 causes, via the contact drive lever 10, the normally open contact 4b, 12 to be closed, and a signal available via this contact operation can be used to display the operation of the overload relay and to open an electromagnetic contactor connected to the main circuit to interrupt the overload current.
  • the lower end of the releasing lever 5, or at least part of it is formed by a compensating bimetal 5a which engages the shifter 2c.
  • the compensating bimetal 5a bends in the same direction so that a shift of the shifter 2c resulting from such bending of bimetals 2a has no influence on the position of releasing lever 5.
  • the illustrated embodiment shows an example in which the movable contact piece 4a of the normally closed contact is directly mounted on the plate spring 7 to reduce the size of the contact switching mechanism
  • this invention is not limited to this aspect, and for example, the movable contact pieces of the normally closed and open contacts can be incorporated in a slider separately from the plate spring 7, and the contacts can be opened and closed by the reversal of the spring 7, as shown in Figure 4.
  • the illustrated embodiments show heat elements 2 comprising bimetals 2a, no particular means or method of sensing temperature or overcurrent conditions is critical to the practice of a relay according to the invention.
  • the reversing spring contact switching mechanism can of course be used in devices other than thermal overload relays.

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  • Thermally Actuated Switches (AREA)
  • Breakers (AREA)
EP97108306A 1996-05-22 1997-05-22 Mécanisme commutateur à contact de ressort réversible et relais thermique de surcharge Withdrawn EP0809270A3 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP126171/96 1996-05-22
JP12617196 1996-05-22
JP268208/96 1996-10-09
JP26820896A JP3298428B2 (ja) 1996-05-22 1996-10-09 反転ばね式接点開閉機構および熱動形過負荷継電器

Publications (2)

Publication Number Publication Date
EP0809270A2 true EP0809270A2 (fr) 1997-11-26
EP0809270A3 EP0809270A3 (fr) 1998-09-02

Family

ID=26462395

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97108306A Withdrawn EP0809270A3 (fr) 1996-05-22 1997-05-22 Mécanisme commutateur à contact de ressort réversible et relais thermique de surcharge

Country Status (3)

Country Link
EP (1) EP0809270A3 (fr)
JP (1) JP3298428B2 (fr)
CN (1) CN1173728A (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2785717A1 (fr) * 1998-11-05 2000-05-12 Schneider Electric Sa Relais thermique dote d'un mecanisme a lame-ressort
FR2817391A1 (fr) * 2000-11-30 2002-05-31 Fuji Electric Co Ltd Dispositif de declenchement en cas de surcharge pour un disjoncteur
US6459355B1 (en) * 1999-12-01 2002-10-01 Fuji Electric Co., Ltd. Thermal overload relay
CN105575738A (zh) * 2016-01-28 2016-05-11 成都绿迪科技有限公司 一种供电热继电器
CN110277286A (zh) * 2018-03-13 2019-09-24 浙江思创电力科技股份有限公司 一种断路器机构
DE102010002499B4 (de) * 2009-03-27 2021-02-11 Fuji Electric Fa Components & Systems Co., Ltd. Thermisches Überlastrelais
US10957507B2 (en) 2018-06-27 2021-03-23 Appleton Grp Llc Mechanism for indirect access to an actuator on an apparatus disposed within a housing

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1098023C (zh) * 1996-01-11 2003-01-01 揖斐电株式会社 印制布线板及其制造方法
CN1293581C (zh) * 2004-08-10 2007-01-03 浙江正泰电器股份有限公司 一种双撞击快速开关装置
JP5003426B2 (ja) * 2007-11-20 2012-08-15 富士電機機器制御株式会社 熱動形過負荷継電器
CN104167329B (zh) * 2013-05-17 2018-12-04 郭永明 高精度热继电器
CN104282504B (zh) * 2014-10-10 2016-07-06 成都锐奕信息技术有限公司 具有增加控制灵敏度功能的继电器
CN107204260A (zh) * 2017-06-08 2017-09-26 无锡市飞沪科技有限公司 一种带有自动保护的热继电器

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1564704A (fr) * 1968-02-21 1969-04-25
DE2702851A1 (de) * 1977-01-25 1978-07-27 Ellenberger & Poensgen Bimetallgesteuerter schalter
GB2196477A (en) * 1986-10-17 1988-04-27 Mitsubishi Electric Corp Thermal overcurrent protective relay
US4908594A (en) * 1987-07-14 1990-03-13 Fuji Electric Co., Ltd. Thermal overload relay
EP0360215A2 (fr) * 1988-09-20 1990-03-28 Fuji Electric Co., Ltd. Ressort d'inversion pour un relais de surcharge thermique et méthode pour sa fabrication
EP0563775A1 (fr) * 1992-03-31 1993-10-06 Ellenberger & Poensgen GmbH Disjoncteur de protection commandé par bimétal

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1564704A (fr) * 1968-02-21 1969-04-25
DE2702851A1 (de) * 1977-01-25 1978-07-27 Ellenberger & Poensgen Bimetallgesteuerter schalter
GB2196477A (en) * 1986-10-17 1988-04-27 Mitsubishi Electric Corp Thermal overcurrent protective relay
US4908594A (en) * 1987-07-14 1990-03-13 Fuji Electric Co., Ltd. Thermal overload relay
EP0360215A2 (fr) * 1988-09-20 1990-03-28 Fuji Electric Co., Ltd. Ressort d'inversion pour un relais de surcharge thermique et méthode pour sa fabrication
EP0563775A1 (fr) * 1992-03-31 1993-10-06 Ellenberger & Poensgen GmbH Disjoncteur de protection commandé par bimétal

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2785717A1 (fr) * 1998-11-05 2000-05-12 Schneider Electric Sa Relais thermique dote d'un mecanisme a lame-ressort
WO2000028560A1 (fr) * 1998-11-05 2000-05-18 Schneider Electric Industries S.A. Relais thermique dote d'un mecanisme a lame-ressort
US6507266B1 (en) 1998-11-05 2003-01-14 Schneider Electric Industries Sa Thermal relay provided with a spring blade mechanism
US6459355B1 (en) * 1999-12-01 2002-10-01 Fuji Electric Co., Ltd. Thermal overload relay
DE10058068B4 (de) * 1999-12-01 2007-05-16 Fuji Electric Co Ltd Thermisches Überlastrelais
FR2817391A1 (fr) * 2000-11-30 2002-05-31 Fuji Electric Co Ltd Dispositif de declenchement en cas de surcharge pour un disjoncteur
DE102010002499B4 (de) * 2009-03-27 2021-02-11 Fuji Electric Fa Components & Systems Co., Ltd. Thermisches Überlastrelais
CN105575738A (zh) * 2016-01-28 2016-05-11 成都绿迪科技有限公司 一种供电热继电器
CN110277286A (zh) * 2018-03-13 2019-09-24 浙江思创电力科技股份有限公司 一种断路器机构
US10957507B2 (en) 2018-06-27 2021-03-23 Appleton Grp Llc Mechanism for indirect access to an actuator on an apparatus disposed within a housing

Also Published As

Publication number Publication date
JP3298428B2 (ja) 2002-07-02
JPH1040795A (ja) 1998-02-13
EP0809270A3 (fr) 1998-09-02
CN1173728A (zh) 1998-02-18

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