FR2725303A1 - AVERAGE VOLTAGE SWITCH OR CIRCUIT BREAKER - Google Patents

Abstract

The present invention relates to a medium voltage switch or circuit breaker. This circuit breaker (or switch) includes an arc extinguishing chamber (5) containing a fixed arcing contact (1) and a moving arcing contact (2) connected to a control mechanism (C) ensuring closure. and the separation of said contacts (1, 2), the pressure of the contacts (1, 2) being maintained by a spring (3) acting on the movable contact (2), and is characterized in that it comprises an accumulation mechanism energy (A) cooperating with the aforementioned control mechanism (C) so as to ensure during a closing operation successively, the closing of the arcing contacts (1, 2) then compression of the spring (3), said spring (3) then acting on the movable contact (2) to ensure the contact pressure (1, 2), the energy accumulated during the compression of the spring being used to ensure the rapid separation of the contacts (1, 2) during an opening maneuver.

Description

INTERRUPTER OR DISCONNECT-R MNIOYENNE VOLTAGE

  The present invention relates to a medium voltage switch or circuit breaker comprising an arc extinguishing chamber formed of a cylinder closed by two bottoms, said chamber enclosing a fixed arcing contact integral with one of the abovementioned bottoms and electrically connected to a first current supply conductor, and a movable arc contact slidably mounted longitudinally across the other of the two bottoms and electrically connected to a second current supply conductor. The aforementioned moving-arc contact is moved in translation by a control mechanism ensuring the closing and the separation of the arcing contacts, the pressure of said contacts in the closed position being maintained thanks to a pressure spring acting on the moving contact. and whose force substantially corresponds to the electrodynamic repulsion forces of the arcing contacts generated by

the passage of the current.

  Japanese Patent Application No. 190063/1993 describes several embodiments of a circuit breaker, one of which has the characteristics mentioned above. According to this embodiment, the pressure spring is mounted in compression between an intermediate piece acting on the movable contact and a plate connected to a control rod.

  articulated on the circuit breaker support.

  Also known is a circuit breaker, described in the patent document FR 2 677 168 of the applicant, comprising two main contacts shunted by two arcing contacts abutting in the closed position. The movable contact is controlled by a mechanism comprising, on the one hand, a toggle joint formed by a crank and a connecting rod to said moving contact, and, on the other hand, a pressure spring precompressed between the crank and a journal belonging to the connecting rod. connection and sliding in a slot provided in said crank, said spring being active when the toggle is in the vicinity of the neutral position. However known circuit breakers of the kind mentioned above have some

  disadvantages. One of these disadvantages is that the inertia of moving parts.

  during opening and closing operations of the arcing contacts, influences the speed of movement of the moving contact. Another of these drawbacks is that the maintenance of the contact force generates stresses in the parts outside the cutoff device because the control mechanism of the movable contact participates in the maintenance of the

contact pressure.

  The present invention solves these problems and proposes a switch or circuit breaker of simple design and reduced size, reducing the number of moving parts whose inertia affects the speed and acceleration of the moving contact, while removing the constraints generated. in the parts outside the cut-off device during the maintenance of the contact pressure. To this end, the subject of the present invention is a medium-voltage electrical switch of the kind including an arc-extinguishing chamber of substantially cylindrical shape and closed by two fixed bases, said chamber enclosing a fixed arc contact of the one of the abovementioned bases and electrically connected to a first current supply conductor and a movable arcing contact mounted to slide longitudinally through the other of the two bottoms, said movable contact being electrically connected to a second supply conductor current and being moved by a control mechanism ensuring the closing and separation of said arcing contacts, the pressure of the contacts in the closed position being held by a spring acting on the movable contact, this switch being characterized in that comprises an energy storage mechanism cooperating with the aforementioned control mechanism so as to ensure during a successful closing maneuver essentially, the closing of the arcing contacts, then a compression of the aforementioned spring, said spring in the compressed state acting on the movable contact to realize the pressure of the arcing contacts, the energy accumulated during the compression of the spring being used to ensure rapid separation

  arcing contacts during a maneuver opening said contacts.

  According to a particular embodiment, the above-mentioned energy storage mechanism comprises a generally shaped frame-shaped driver, slidably mounted in a first fixed support and housing the aforesaid chamber, said trainer being supported, by its upper part, on the one of the ends of the aforementioned spring whose other end is supported on the aforementioned support, while its lower part cooperates with a dead-center system connected in an articulated manner on the one hand, to the control mechanism and on the other hand part, at

mobile arc contact.

  According to a particular characteristic, this mechanism further comprises a stop intended to limit the travel in translation of the trainer during an opening maneuver of the

Arc contacts.

  According to a particular characteristic, the neutral passage system comprises at least one toggle joint hingedly connected to a driving rod of the control mechanism, said toggle lever being in the vicinity of the neutral position in the closed position of the arcing contacts. and cooperating by its lower part with the lower part of the coach. Advantageously, this system comprises two knee pads located on either side of the coach and connected by a connecting element bearing on the lower part of the coach. According to a particular embodiment, the above-mentioned toggle joint (s) is (are) each constituted by two connecting rods connected in an articulated manner by one of their ends between them, said connecting rods being connected in an articulated manner by their other end respectively, to the movable contact and to a guide rod, articulated on a second

fixed support.

  Advantageously, the or toggle (s) is (are) each constituted by a double crank articulated on the movable arcing contact and comprising two simple cranks respectively hingedly connected to the driving rod of the control mechanism and a connecting rod connected in a hinged manner to a guide rod

  articulated on a second fixed support.

  According to an alternative embodiment, the neutral passage system comprises at least one cam connected in an articulated manner to a drive rod of the control mechanism and comprising an arcuate groove in which slides a lug secured to the movable contact, said cam being further connected in articulated manner to a guide rod articulated on a second fixed support and cooperating with the lower part of

the coach.

  According to another characteristic, the first and second supports are respectively connected

  electrically to the first and second current leads.

  According to another characteristic, the aforementioned spring is mounted around the rod of a screw passing through the upper part of the driver and the first fixed support to screw into

the fixed arc contact.

  Advantageously, at the end of opening, the movable contact rests on a stop formed on the driver so that the shock energy generated by the displacement of the contact

  mobile is absorbed by the spring.

  But other advantages and features of the invention will appear better in the

  detailed description which follows and refers to the accompanying drawings given solely for the purpose of

  and in which: - Figure I is a partially sectional view illustrating a pole of the circuit breaker according to a

  particular embodiment of the invention.

  FIGS. 2 to 4 show sectional views of the same pole fixed on a frame, respectively in the open position of the arcing contacts, in the closed position without contact pressure, and in the closed position with retention of the contact pressure, - Figures 5 to 7 illustrate, in schematic views, the operation of the circuit breaker

  respectively in the three positions mentioned above.

  FIG. 5a illustrates a schematic partial view of another embodiment of the system of

dead point of the invention.

  In the figures, we see one of the poles of a circuit breaker according to a particular embodiment of the invention intended to be fixed on a frame E. This pole D comprises an arc extinction chamber 5 constituted by a closed cylinder by two funds 5a, 5b and containing

  two arcing contacts 1, 2 respectively fixed and movable.

  The fixed arcing contact 1 is integral with one of the abovementioned bottoms 5a and electrically connected to a first current supply conductor 20, while the movable arcing contact 2 is slidably mounted through the other 5b fund being electrically connected to a second current supply conductor 21, and mechanically to a control mechanism C. This control mechanism C comprises a driving rod (or control rod 11) hingedly connected to a double crank 30 connected to another rod 31, which is connected to a drive shaft 32. According to the invention, this light D further comprises a so-called energy storage mechanism A comprising a drive device, said 4, generally shaped frame, a dead center system S, and a pressure spring 3. The driver 4 comprises an upper part 4a forming a pedestal and a lower part 4b U-shaped, these parts are connected by two tie rods 4c, 4d slidably mounted through a support 6, said first, constituting the first supply conductor of the aforementioned current 20. The U-shaped lower part 4b of the driver 4 is slidably mounted through a second support 13 constituting the second current supply conductor 21. The arc extinguishing chamber 5 is housed inside the driver 4 and the pressure spring 3 is supported, by one 3a its ends, on the upper part 4a of the trainer, and by its other end 3b on the aforementioned fixed support 6. This spring is also mounted around the rod 22 of a screw 23 passing through the upper portion 4a of the coach 4 and the first support 6 to screw

in the fixed arc contact 1.

  According to a particular embodiment of the invention, the dead-center system S has on each side of the driver 4, two knee pads 7, 8 each consisting of

  two rods 9,10 connected in an articulated manner between them, by one of their ends.

  Advantageously, one of the connecting rods is a double crank 14 consisting of two simple cranks 15, 16, said crank being hingedly connected at a point between its two cranks 15, 16 to the movable contact 2. One 16 of the cranks single is further connected to an intermediate rod 17, which is connected to a guide rod 12 hinged to the second fixed support 13, while the other crank 15 is hingedly connected to the control rod 1 1. In this embodiment, the two knee pads 7, 8 are connected by an axis or the like (not shown) resting on the lower part 4b of

the coach 4.

  According to an alternative embodiment, illustrated in FIG. 5a, the neutral system S comprises, on each side of the driver 4, a cam 18 hinged to the control rod 11 and comprising a circular groove 18a in which slides a lug 18b integral with the movable arcing contact 2, said cam 18 being further articulated on the connecting rod of

  said guide 12 while bearing on the lower part 4b of the coach 4.

  The operation of the circuit breaker of the invention will be described below with reference to the

FIGS.

  In FIGS. 2 and 5, the cut-off mechanism of the pole D is in the stable open position, the arcing contacts 1, 2 being open. When moving from the position of FIG. 2 (respectively 5) to the position of FIG. 3 (respectively 6), the control rod 11 moves in the direction of arrow F, which has led to rotation of the crank 14 (respectively of the connecting rod 9) about the X axis, counterclockwise, causing an upward movement of the movable contact 2, until the contacts of arc 1, 2 are closed (Figures 3 and 6). In this position, the contact pressure is not assured. When the closing maneuver is continued, the crank 14 and the connecting rod 17 (or the two connecting rods 9, 10) approach the alignment, which generates a

  pushing on the lower part 4b of the coach 4 causing its movement down.

  It follows a compression of the pressure spring 3 (Figures 4 and 7) which, when the closing maneuver is completed, applied by reaction, a force on the upper part 4a of the driver 4 which is thus solicited upwards and exerts by its lower part 4b, a force on the movable contact 2, thus ensuring the contact pressure of the arcing contacts 1, 2. The circuit breaker is then in the closed position stable. Note that in this position, the toggle 7, 8 may not be quite in neutral (that is to say in the aligned position of the rods 9, 10, or the crank 14 and the rod 17). During an opening maneuver of the circuit breaker, the drive rod is moved in the opposite direction to the previous one, which causes a rotation of the crank 14 and the connecting rod 17. At the beginning of opening, the energy accumulated by the spring 3 during compression, is converted into kinetic energy, and the driver 4 is biased upwards by the spring 3 until it abuts against the stop 33 formed in the upper part of the screw 23 (Figures 2,3 and 4), position shown in Figures 3 and 6. In this step, the crank 14 and the rod 17 (or connecting rods 9, 10) are set speed, causing a separation to high speed of the arc contacts 1, 2, and the abutment of the movable contact 2, on another stop 34, formed on the driver 4, the shock energy is thus absorbed by the

pressure spring 3.

  The operation of the circuit breaker comprising a drive system of the movable contact 2 will not be described by means of a cam 18 which is the same as that

previously described.

  Note that the invention can be applied indifferently to the realization of a switch or a circuit breaker or any system requiring a rapid cut-off device. Therefore, thanks to the invention, a circuit breaker or switch has been realized in which the inertia of the parts related to the maintenance of the contact pressure does not affect the speed of movement of the moving contact, and in which the stresses due to the maintenance of the effort of

  contact are minimized in the rooms outside the circuit breaker.

  Of course, the invention is not limited to the described and illustrated embodiments which

  have been given only as an example.

  On the contrary, the invention includes all the technical equivalents of the means thus described.

  that their combinations if they are carried out according to his spirit.

Claims (8)

  1. A medium voltage electrical switch of the kind including a substantially cylindrical arc extinguishing chamber and closed by two fixed bases, said chamber containing a fixed arcing contact integral with one of the abovementioned bases and electrically connected to a first current-supplying conductor and a movable-arc contact arranged longitudinally sliding through the other of the two bottoms, said movable contact being electrically connected to a second current-supplying conductor and being driven by a control mechanism closing and separating said arcing contacts, the pressure of the contacts in the closed position being held by a spring acting on the movable contact, characterized in that it comprises an energy storage mechanism (A) co-operating with the aforementioned control mechanism (C) so as to ensure, during a closing maneuver successively, the closing of the arcing contacts (1, 2) and then a compression ion of the aforementioned spring (3), said spring (3) in the compressed state acting on the movable contact (2) to achieve the pressure of the arcing contacts (1, 2), the energy accumulated during the compression of the spring (3) being used to ensure rapid separation of contacts   arc (1, 2) during a maneuver opening said contacts.   2. Switch according to claim 1, characterized in that the aforesaid energy storage mechanism (A) comprises a trainer (4) in general frame form, slidably mounted in a first fixed support (6) and housing the chamber aforementioned (5), said driver (4) being supported, by its upper part (4a), on one (3a) of the ends of said spring (3) whose other end (3b) bears on the said support (6), while the lower part (4b) of the driver cooperates with a neutral system (S) connected in an articulated manner on the one hand to the control mechanism (C), and   on the other hand, in contact with moving bow (2).   3. Switch according to claim 2, characterized in that it further comprises a stop (33) intended to limit the travel in translation of the driver (4) during a maneuver opening of the arcing contacts.   Switch according to Claim 2 or 3, characterized in that the dead-center passage system (S) has at least one toggle joint (7) hingedly connected to a drive rod (11) of the control mechanism ( C), said toggle (7) being in the vicinity of the neutral position in the closed position of the arcing contacts (1, 2) and co-operating at its lower part with the lower part (4b) of the driver (4). 5. Switch according to claim 4, characterized in that the dead-center system (S) comprises two knee pads (7, 8) located on either side of the driver (4) to and connected by an element. connecting link resting on the lower part (4b) of the coach (4). 6. Switch according to claim 4 or 5, characterized in that the aforementioned knee (s) (7, 8) is (are) each constituted by two rods (9, 10) connected in a manner articulated by one of their ends to each other, said connecting rods (9, 10) being connected in an articulated manner by their other end respectively, to the moving contact   (2) and a guide rod (12) hinged to a second fixed support (13).   7. Switch according to any one of claims 4 to 6, characterized in that the (or   the knee pads (7, 8) are (are) each constituted by a double crank (14) hinged to the movable arcing contact and comprising two simple cranks (15, 16) respectively connected in an articulated manner to the drive rod (11) and to a link rod (17) hingedly connected to a guide rod (12), which is   articulated on a second fixed support (13).   8. Switch according to any one of claims 1 to 3, characterized in that the dead-center system (S) comprises at least one cam (18) hingedly connected to a driving rod (11) of the control mechanism (C) and having an arcuate groove (18a) in which slides a lug (18b) integral with the movable contact (2), said cam (18) being hingedly connected to a guide rod (12) hinged to a second fixed support (13) cooperating with the lower part (4b) of the coach (4).   9. Switch according to any one of claims 6 to 8, characterized in that the   first and second supports (6, 13) are respectively electrically connected to the first   and second current supply conductors (20, 21).   1O.Switch according to any one of claims 2 to 9, characterized in that the   said spring (3) is mounted around the rod (22) of a screw (23) passing through the upper part (4a) of the driver (4) and the first fixed support (6) to be screwed into the fixed arc contact (1).   11. Switch according to any one of the preceding claims, characterized in that   at the end of opening the movable contact (2) abuts on a stop (34) formed on the driver (4) so that the shock energy generated by the displacement of the   movable contact (2) is absorbed by the spring (3).