FR2621418A1 - PROTECTION SWITCH WITH ARC SHUTDOWN SCREEN - Google Patents

Abstract

The apparatus according to the invention comprises in a housing 11: a fixed contact 12 and a movable contact 13 carried by a movable arm 14, with elastic return to closing; a trip device 19 able to act on the contact carrier arm 14 in the opening direction via a lock 25 in response to a short circuit; an arc cutting screen 27 driven by the trip device 19 in response to a short circuit; a manual control member 32 connected to the contact carrier arm 14. The screen 27 is actuated following an opening by manual control by means of a drive member 39 secured to the manual control member 32.

Description

PROTECTION SWITCH WITH ARC SHUTDOWN SCREEN.

  The present invention relates to an electrical appliance

  single-pole or multi-pole protection breaker allowing a power cut following an automatic trip in the event of a short-circuit overcurrent or an opening by manual control and comprising in a case: - at least one fixed contact and one movable contact, - a movable arm carrying the movable contact and resiliently biased in the direction of closing the contacts,

  - a triggering device actuating in response to a surin-

  short-circuit current, an automatic tripping lock cooperating with the contact-carrying arm to cause the latter to move in the direction of opening of the contacts, - a movable arc-breaking screen occupying a rest position towards which it is recalled by a spring and being

  driven by the triggering organ in response to a surin-

  short-circuit current to interpose between the contacts,

  - a manual control member connected to a drive member

  ment cooperating with the contact-carrying arm to drive the movement of the control by maneuvering

  arm in the opening direction of the contacts.

2621ó18

  - 2 - Such a switch device called arc cut screen is described in patent FR - 2 577 712. This device is

  a disconnector-circuit breaker whose role is to isolate electric

  protect and protect against short circuits a motor starter assembly (contactor, thermal relay). We also know that it can be requested from the same protection switch ensuring a cut-off following an automatic tripping on short-circuit, to also be able to cut overload currents, fixed by standards, in response to the actuation of a

manual command.

  However, up to now, in the screen cut-off technique, in particular in the circuit breaker of the type described in the aforementioned patent, the arc cut-off screen is not requested by the automatic tripping device on short-circuit only from the trip threshold thereof and therefore only participates in the cut-off in the event of

short circuit.

  The object of the present invention is in particular to solicit the

  same arc cutout screen as well when triggered

  automatically at high overcurrents, that is to say for short-circuit currents, than when opening by manual control at low currents, that is to say both for overload currents and for currents with a value less than or equal to that of the rated current of the device. Another purpose is to prevent, during manual opening, the unlocking of the mechanical lock of the device, which advantageously makes it possible to dispense with the rearming thereof after opening

manual.

  According to the invention, a device for protecting the

  type described above, is more particularly charac-

  -3- terized in that it comprises a screen drive member in the event of manual opening, subject to the manual control member and connected to the screen to drive the latter against its return spring during manual opening, so that the screen is interposed between the contacts. The proposed solution thus makes it possible to benefit from the action of the screen thanks to a simple mechanical connection between the manual control member and the screen, in order to favor

  cut-off during manual opening.

  According to another characteristic of the invention, the screen drive member in the event of manual opening consists of a projecting finger which is formed on a movable rocker driven by the manual control member

  and which cooperates during a manual opening with a shoulder-

  on the screen. In the case of a cut-off screen

  of arc of the rotary type, said shoulder is formed, preferably

  rence, on the periphery of the screen.

  Other characteristics and advantages of the invention

  will appear better in the detailed description which follows and

  refers to the appended drawings given solely by way of example and in which: FIGS. 1 to 4 schematically show in elevation a protective switch according to the invention, respectively in the closed, cut-out on short-circuit positions, d 'opening

  manual and reset following a trigger

  chement on short circuit; Figure 5 is a front view of the switch in

a three-pole version.

  In FIGS. 1 to 4, an intensity threshold switching device, designated by the general reference 10, comprises a housing 11 in which are housed at least one fixed contact 12 and a movable contact 13 carried by an arm of contact 14 which is pivotally mounted on a bearing 15 of axis Ai in the housing 11 and is biased in the direction of closing of the contacts by a not shown return spring. The fixed contact 12 is connected to an input terminal 16 via an electrical connection 17 comprising a coil 18 belonging to an electromagnet which constitutes the automatic short-circuit tripping member 19 of the device in question, while the movable contact 13 is connected by a link

  conductive 20 to an output terminal 22.

  In the closed position of the contacts 12, 13, shown in FIG. 1, the current entering through the terminal 16 passes through the coil 18 and the closed contacts 12, 13 before exiting through

the opposite terminal 22.

  Inside the coil 18 of the electromagnetic trip device

  that 19 is slidably mounted a magnetic core 24 shaped as a plunger which is capable of actuating in position

  attracted following a short circuit a trip lock

  schematically shown in 25 acting on the support arm

  contact 14 in the opening direction of the contacts (figure 2).

  A cut-off screen 27 made of insulating material, known per se,

  is rotatably mounted on a fixed pivot 28, of axis X-X paral-

  lele to axis A1, in the boot 11 and is actuated direct-

  ment or indirectly by the plunger core 24 of the declen-

  electromagnetic heat sink 19 in response to a short circuit overcurrent to interpose between the fixed contacts 12

  and mobile 13 (Figure 2) to help stretch, cool

  direct and destabilize the cutting arc. In the present example-

  ple of embodiment, the rotary screen 27 is directly hooked on a tail 29 of the plunger core 24 and can be propelled by the latter against a return spring shown diagrammatically at 30 under the action of the plunger core during A short-circuit.

- 5 -

  A manual control button 32 located outside the boot 11il cooperates with a control rocker 33 of the contact carrier arm; the button is pivotally mounted around an axis A2 perpendicular to the axis Al, while the rocker is pivotally mounted on a bearing 34 of axis A3 parallel to the axis Al. A mechanical connection suitable for engagement and / or with cam allows the rotary movement of the button 32 to be transformed into a correlative rotary movement of the rocker 33. In the present embodiment, the rocker 33 comprises an imprint with two notches 33a, 33b intended to cooperate with a connecting piece 36 carrying let's stick 36a, 36b; the part 36 is capable of rotating around the axis A2 in response to the pivoting of the button 32 and it

  has for this purpose a square 36c cooperating with a hollow

button 32a 32a.

  The rocker 33 has a projection or other element

  support 38 capable of application on the support arm

  contact 14 to cause the latter to move in the opening direction of the contacts in response to pivoting of the rocker under the action of button 32 during an order

manual opening (figure 3).

  According to the invention, there is also provided on the rocker 33 a drive element 39 intended to cooperate with the screen 27 during the pivoting of the rocker in the event of manual opening in order to rotate the screen 27 in the direction of its interposition between the contacts. This drive element 39 is presently produced in the form of a projecting finger which is applied against a shoulder 27a provided on the periphery of the screen 27 in response to the pivoting of the rocker 33 following manual opening so to drive the screen against its return spring 30 and this, until the interposition of said

  screen between the contacts (figure 3). Finger 39 of the rocker

  their 33 is moreover shaped so as to be in - 6 -

  engagement with the screen 27 throughout the bascu-

  their between the extreme closed and open positions

re contacts.

  The support element 38 and the drive finger 39 of the rocker 33 are arranged relative to each other so that the pivoting of the rocker during a manual opening command first causes the separation of the contacts by means of the support element 38, then the interposition of the screen 27 between the contacts opened by means of the finger

39.

  The switch device 10 described above operates in the following manner: In the closed position of the contacts (FIG. 1), the button 32 capable of rotating around the axis A2 occupies the on position (denoted "1" on the Figure 5) and cooperates via the connecting piece 36 with studs 36a, 36b with the indentation 33a, 33b of the rocker 33. The finger 39 of the rocker 33 is not applied in the position of

  closure against the shoulder 27a of the screen 27.

  The device reaches the trigger position shown

  Figure 2 when a short circuit current flows through the

  coil 18 of the trip electromagnet 19. The core plun-

  geur 24 is then attracted and moves to the left against a return spring shown diagrammatically at 40 by actuating the lock 25, which lock rotates the contact-carrying arm 14 counterclockwise, and by rotating it in the opposite direction time the screen 27 which is interposed between the fixed contacts 12 and mobile 13 in order to promote the cut

of the arc.

  During this short-circuit trip, the rocker

33 does not change position.

- 7-

  To cut an overload current, or even to interrupt

  pre the circuit in normal service, the device is put in the open position (figure 3) when the operator turns the button 32 around the axis A2 to bring it from the on position to the off position (noted "0" in the figure). The rotation of the button 32 is then 90 but may well

  heard from a different angle.

  The rotation of the button 32 from "1" to "0" determines the rotation around the axis A2 of the connecting piece 36 whose pin 36a engages in the notch 33b of the imprint of the rocker 33. It results in a counterclockwise pivoting of the rocker 33 about the axis A3 during which, on the one hand, the support element 38 causes a counterclockwise pivoting of the contact-carrying arm 14 and, on the other hand, the finger 39 is in abutment against the shoulder 27a of the screen and drives in direction

  clockwise the rotating screen 27 which is interposed at the end of the pivoting

  ment of the rocker 33 between the fixed 12 and movable 13 contacts to favor the cutting of the arc. Despite the reverse rotational movements of the rocker 33 and the screen 27, the finger 39 of the rocker 33 remains engaged in the shoulder 27a of the screen 27 at the end of pivoting of the rocker (see FIG. 3). It will be noted that the angular displacement of the contact-carrying arm 14 during a manual opening is greater than that of said arm during a tripping on short circuit, like this

  is known from patent FR-2,577,712.

  Since the plunger core 24 of the electro-

  magnetic 19 remains in the rest position during the manual opening phase which has just been described, it therefore does not actuate lock 25, which makes it possible to avoid unlocking of said lock and, consequently, its

rearmament.

  Under these conditions, after opening by manual control, the device is returned to the closed position.

- 8 -

  - simply by clockwise rotation of the button 32 from "0" to "1". The rotation of the button 32 causes a clockwise pivoting of the rocker 33 which allows, by the erasure of the element

  38 and finger 39 and under the action of spring 30, the rotation

  counterclockwise display 27 combined with closing

  contacts 12, 13 up to the position of FIG. 1.

  After tripping on a short circuit, resetting (fig.

  re 4) is effected by rotation of the button 32 in anti-anti-

  raire beyond position "0" in Figure 5 to the position marked "RESET" in the same figure. The plunger core 24 and the screen 27 (in solid lines in FIG. 4) having returned to their rest position, this rotation of the button 32 causes the rocker 33 to rotate counterclockwise, including the finger 39, illustrated in phantom in FIG. 4, come

  apply against the shoulder 27a of the screen 27 and entrain-

  do this clockwise to the position shown in

  dashed lines in FIG. 4, and of which the support element 38 drives

  do an angular displacement of the contact carrier arm 14 slight-

  ment higher than that of said arm in case of manual opening-

  the, authorizing the rearming of the lock 25.

  When button 32 is returned to its "1" position, it

  that a clockwise pivoting of the rocker 33 which authorizes, by the erasure of the element 38 and of the finger 39 and under the action

  of the spring 30, the counterclockwise rotation of the screen 27 combines

  ford with the closure of contacts 12, 13 to resume the

initial position of figure 1.

  In a multipolar version of the switch, the manual control of the contact arms or bridges 14 of the various poles is carried out from the button 32 on as many rockers 33 as there are poles, the rockers 33 being coupled together . It goes without saying that modifications can be made to the switch device described without departing from the scope of the invention.

Claims (5)

Claims   1. Protective switch electrical device enabling a power cut following an automatic tripping in the event of a short-circuit overcurrent or an opening by manual control, comprising in a housing (11):   - at least one fixed contact (12) and one movable contact (13), - a movable arm (14) carrying the movable contact (13) and resiliently biased in the direction of closing of the contacts, - a triggering member (19) operating in response to a   short circuit overcurrent a trip lock   automatic ment (25) cooperating with the contact-carrying arm (14) to cause the latter to move in the direction of opening of the contacts,   - a movable arc break screen (27) occupying a position   rest position towards which it is recalled by a spring (30) and being driven by the triggering member in response to a short-circuit overcurrent to interpose between the contacts, - a manual control member (32) connected to a member drive (38) cooperating with the contact support arm (14) to drive by movement of the control member a movement of the arm in the direction of opening of the contacts, characterized in that the apparatus comprises a member drive (39) of the screen in the event of manual opening, subject to the manual control member (32) and acting on the screen (27) to drive the latter against its spring reminder (30) during manual opening,   so that the screen is interposed between the contacts. - 10 -26 2 1418 - 1o -   2. Electrical switch device as claimed   cation 1, characterized in that it comprises a movable rocker (33) driven by the manual control member (32), and that the screen drive member is constituted by a   protruding finger (39) formed on the rocker (33) and cooperating   rant with a shoulder (27a) provided on the screen (27) when manual opening.   3. Electrical switch device as claimed   cation 2, in which the arc cutting screen (27) is of the rotary type, characterized in that the shoulder (27a) is formed on the screen periphery.   4. Electrical switch device as claimed   cation 3, characterized in that the rocker (33) is pivotally mounted on a bearing (34) with an axis parallel to the axis of rotation of the screen (27).   5. Electrical switch device according to one of claims 2 to 4,   characterized in that the rocker (33) is also provided with the drive member (38) of the contact carrier arm, the   respective drive members (38, 39) of the support arm   contact (14) and of the screen (27) being positioned relative to each other on the rocker (33) so that, after the operation of the manual control member   (32), moving the rocker first produces the opening   ture of the contacts, then the interposition of the screen between the contacts.