EP0567416B1 - Mechanic interlocking device of two moulded case circuit breakers - Google Patents

Description

The invention relates to a mechanical interlocking device for a first and a second molded case circuit breaker to prevent simultaneous closing of the two circuit breakers, each circuit breaker having a pushbutton with two stable positions, a first position representative of the circuit breaker open position and a second position representative of the circuit breaker closed position and a transmission lever with two stable positions, a first inactive position and a second circuit breaker tripping control position.

An interlocking device of the type mentioned, is used in particular in source inverters, allowing the supply of an installation by one or the other of the sources. Interlocking can be electrical when the circuit breakers are remote-controlled or mechanical when they are placed side by side on a plate. Mechanical interlocks are made using rods connecting the control handles and these rod sets are complicated and of uncertain reliability. They depend on the type of order.

Document US-A-4,286,242 describes an interlocking system for open type circuit breakers; the mechanism of this type of circuit breaker has two latchings, namely a closing latch and an opening latch and can therefore occupy four different states, respectively open disarmed, open armed, closed disarmed and closed armed. Consequently, during the closing of one of the two circuit breakers, the interlocking has the effect of acting on the opening latching of the other circuit breaker, this action being followed by effect only if the other circuit breaker is effectively closed.

This interlocking system is not applicable to molded case circuit breakers, for which the mechanism with control by means of a handle has only one latching, the handle being able respectively to occupy the following three positions: a first position closing, a second opening position and an intermediate release position. On this type of mechanism, an action on the latching, while the circuit breaker is in the open position, causes a passage to the tripping position, requiring resetting before being able to close the circuit breaker.

In addition, it requires manual intervention on the front and rear faces of the fixing plate during assembly / disassembly of the circuit breakers, and is therefore not suitable for withdrawable circuit breakers.

Finally, the circuit breaker test operations associated with this type of interlocking mechanism, carried out after dismantling the circuit breakers, require the transmission lever to be blocked in order to authorize the closing of the circuit breaker.

The present invention aims to allow the realization of a simple and reliable mechanical interlocking device, for molded case circuit breakers, regardless of their direct, rotary or electric control mode, and their fixing, fixed or withdrawable.

The device according to the invention is described in claim 1.

The interlocking mechanism is transferred to the rear face of the molded boxes and to the plate on which these rear faces are fixed. The transmission by rotary bars, in particular by coaxial rotary bars, one of which is tubular, is particularly robust and reliable, and the connection with the circuit breakers takes place automatically when the latter are fixed on the plate. The pushers representative of the position of the circuit breaker contacts are interposed between the contact carrier bar or between a crank secured to this bar and receiving cranks fixed to the connecting bars extending between the two circuit breakers. These bars carry at their opposite end rotary cams, capable of engaging a rocker lever actuating a transmission lever which displaces the latching or the tripping bar of the tripping device of the circuit breaker. The mechanical connection bars are mounted on bearings integral with the plate, and these bars are biased by springs in a direction holding the receiving cranks in support of the pushers. The elements of the interlocking device, associated directly with the circuit breaker, in this case, the pushers and the transmission levers with their rocker can be mounted on any type of circuit breaker, and in a particularly simple manner. These elements can be used for actuating other auxiliaries, in particular in a pre-trip device described in the jointly filed patent application.

Other advantages and characteristics will emerge more clearly from the description which follows, of an embodiment of the invention, given by way of example and shown in the appended drawings in which:

Figure 1 is a schematic elevational view in axial section of a circuit breaker according to the invention, shown in the withdrawn position.

Figures 2, 3 and 4 are views similar to that of Figure 1, showing respectively the circuit breaker during racking-in, in the plugged-in position, and during racking-out.

Figure 5 is an elevational view in axial section of an interlocking device of two circuit breakers, a part surrounded by a broken line being shown in the position corresponding to the associated circuit breaker.

Figure 6 is a view similar to that of Figure 5, showing the interlocking device in the release position.

Figure 7 is a perspective view of a mounting plate of the two circuit breakers equipped with an interlocking device, only the boxes of the circuit breakers being partially shown.

Figure 8 is a view similar to that of Figure 7, in which one of the parts of the plate is assumed to be removed.

FIG. 9 is an enlarged view of part of FIG. 8.

Figure 10 is a sectional view of a pole of the circuit breaker and its control mechanism.

In FIGS. 1 to 4, a withdrawable circuit breaker consists of a fixed part 10 in the form of a base or a frame, and of a movable part 11 forming the circuit breaker proper, in this case a molded case circuit breaker 12, of which only the base is represented. The circuit breaker 11 of a standard type comprises a bar 53 for supporting the movable contacts 52 of the different poles, to which bar is associated a control crank 13 coupled to a toggle switch 14 of a mechanism 15 for opening and closing the circuit breaker . A pivoting handle 16 controls the manual opening and closing of the circuit breaker by means of an anchored spring 17, on the one hand to the axis 18 of the toggle joint, and on the other hand to the handle 16. The opposite end of the toggle joint 14 is articulated to a hook 19, one of the ends of which is pivotally mounted on a fixed axis 20 and the opposite end of which cooperates with a latch 21. In the locked position, the hook 19 exerts on the locking surface of latch 21 a force in the unlocking direction, by pivoting anti-clockwise, latch 21 being held in the locking position by a pivoting latch 22. The circuit breaker 11 further comprises a trip device (not shown) which actuates the latch 22 during a fault to cause the automatic opening of the circuit breaker by releasing the latch 21 and unlocking of the hook 19. FIG. 1 shows the mechanism 15 in the closed position of the circuit breaker, the opening of the latter being able to be controlled manually by pivoting the handle 16 anticlockwise, or by tripping triggered by the trigger.

When triggered, the handle 16 comes to an intermediate position, and the resetting of the mechanism 15 is obtained by pivoting the handle 16 towards the open position. During this pivoting, a roller 23 integral with the handle 16 engages the hook 19 to bring it back into the locking position by the bolt 21. This rearming position which corresponds to the open position, is a stable position of the lever 16, the latter remaining in this position, even when the hook 19 is unlocked by the trigger.

Such a circuit breaker is described in detail in European patent application EP-A-0 555 158 -Article 54 (3) of the EPC- and the reader will advantageously refer to this request for further details.

55.56 input and output ranges of the different poles of the circuit breaker 11 are connected racking pins 24 projecting from the rear face 25 of the molded housing 12. When the circuit breaker 11 is racked on the base 10, each pin 24 of cylindrical shape comes to be plugged into a fixed racking contact constituted by a tulip 26. The base 10 is constituted by an insulating plate having cells 27 for housing tulips 26 oriented in the direction of the rear face 25 of the molded housing 12. The tulips 26 are extended in the direction of this rear face 25, by insulating guide sockets 28, which cooperate with the pins 24 to position and guide the circuit breaker 11 during the racking-in and racking-out race. .

The circuit breaker 11 is equipped with a pre-trip system constituted on the one hand by a fixed cam 29, carried by the base 10, and on the other hand by a system integral with the mobile part consisting of a support bracket 32, fixed to the rear face 25 of the housing 12, which square carries a rocker arm 31, one of the arms 33 of which is articulated to a transmission lever 30. The rocker arm 31 is pivotally mounted on an axis 34, integral with the bracket 32 , and the opposite arm 35 of the rocker arm 31 carries a pin 36 capable of cooperating with the fixed cam 29. The transmission lever 30 passes through an orifice 37 on the rear face 25, and a passage 38 formed inside the housing 12 for end with a face 39 actuation of the latching 22. The fixed cam 29, the rocker arm 31 and the transmission lever 30 extend in a plane parallel to the racking-in and racking-out direction of the circuit breaker 11, which direction is perpendicular to the face rear 25. The arm 35 carrying the pin 36 of the rocker arm 31 extends substantially in this direction perpendicular to the rear face 25, while the arm 33 articulated to the transmission lever 30 is substantially perpendicular. The profile 40 of the fixed cam has a slot which cooperates with the pin 36 to move the latter during a racking-in movement of the circuit breaker 11, to the left in FIG. 1, then to maintain this pin in the deflected position before releasing it at the end of the racking-in stroke. This deflection movement to the left of the pin 36 causes the rocker arm 31 to pivot clockwise and to slide upwards in FIG. 1 of the transmission lever 30, the face 39 of which engages the attachment 22 to release the bolt 21. The release of the pin 36 authorizes a reverse pivoting of the rocker arm 31 and a sliding down of the transmission lever 30 which again allows the latching of the bolt 21.

The device works as follows:

The circuit breaker being in the closed position, shown in FIG. 1 and withdrawn, the racking-in movement of the circuit breaker 11 is started on the base 10, by introducing the pins 24 into the sockets 28. In this position, the pin 36 doesn’t has not yet engaged the fixed cam 29, and the latch 21 maintains the hook 19. A continued racking-in movement brings the circuit breaker 11 to the position shown in FIG. 2, where the pins 24 are always spaced from the tulips 26 and where the fixed cam 29 has moved the pin 36 to the left in the figure, causing the sliding of the transmission rod 30, which has pivoted the hooking 22. The latch 21 thus released authorizes the pivoting of the hook 19 and tripping of the circuit breaker, the contacts of which open. The circuit breaker being open, it can be plugged in without any risk, and at the end of the racking-in stroke, the pin 36 crosses the slot 40 and is again released from the fixed cam 29 to return to the initial position of movement to the right. In this connected position, the transmission lever 30 is inactive, and the circuit breaker can be opened or closed normally by actuation of the handle 16, FIG. 3 showing the circuit breaker connected in the closed position. Withdrawal is effected by a reverse operation, and firstly the pin 36 engages the cam 29 and is moved to the left in FIG. 4, to actuate the transmission lever 30 and cause tripping of the circuit breaker 11, by release of the latching 22 and of the latch 21. The tripping occurs before the separation of the racking-in contacts 24, 26 which takes place thereafter, the circuit breaker being unloaded. At the end of the withdrawing stroke and in the withdrawn position, the pin 36 leaves the fixed cam 29 to return to the initial position for releasing the coupling. 22 and latch 21, allowing normal operation of the circuit breaker, in particular opening and closing for carrying out tests.

It is easy to see that the pre-trip device can be associated with a standard circuit breaker, by simple fixing of the support 32, with the rocker arm 31 and the transmission lever 30. The pre-trip system is particularly simple and it avoids any false operation.

In FIGS. 5 to 9 which illustrate an interlocking device, the same reference numbers are used to designate parts similar or identical to those of the circuit breaker illustrated in FIGS. 1 to 4, the reference numbers relating to the first circuit breaker being assigned of an index. A first circuit breaker 11 ′ and a second circuit breaker 11, of which only the molded housings 12, 12 ′ are shown in FIG. 7, are fixed to a plate 41, side by side by any suitable means. Each circuit breaker is equipped with a pre-trip device similar to that described above, and comprising a support 32 with a rocker arm 31 and a transmission lever 30. In the fixing position of the circuit breakers 11,11 'on the plate 41, the rear faces 25 are pressed against the plate 41, which has two orifices 42 in which the supports 32 fit together. Each circuit breaker 11,11 'is further equipped with a push button 43,43', one of the ends of which is articulated to the crank 13, and the other end of which projects from the rear face 25, and penetrates into the orifices 42 of the plate 41. The position of the pusher 43 is representative of that of the contacts 52 of the circuit breaker, in this case opening and closing of the circuit breaker.

The plate 41 is fixed at a small distance to a parallel base plate 44 so as to provide an interval, between the plate 41 and the base plate 44, receiving a mechanical connection system between the two circuit breakers 11, 11 '. This connection system consists of two coaxial rotary bars, at least one of which in the form of a tube 45 surrounds the other in the form of an axis 46. The axis 46 is longer than the tube 45, and the parts which protrude on either side of this tube 45 are rotatably mounted in bearings 47 fixed to the base plate 44. The axis 46 pivots freely in the bearings 47, and the tube 45 pivots freely on the axis 46. The tube 45 and the axis 46 extend transversely to the circuit breakers 11, 11 'and respectively constitute a first and a second mechanical connection between these two circuit breakers. To this end, the tube 45 carries at one of its ends opposite the orifice 42 'of the plate 41, a first receiving crank 48' and at the opposite end, opposite the orifice 42, a second rotary cam 49. In an analogous manner, the axis 46 carries, opposite the orifice 42 ', a first rotary cam 49', and opposite the orifice 42 a second receiving crank 48. The receiving cranks 48 , 48 'have a cell housing the end of the pushers 43,43 'and it is easy to see that a movement of the pushbutton 43' of the first circuit breaker 11 'causes the displacement of the associated receiving crank 48', and a pivoting of the tube 45, while that the pusher 43 of the second circuit breaker 11 actuates the second receiving crank 48 and causes pivoting of the axis 46. The rotary cams 49, 49 ′ cooperate with the associated rockers 31 to move the transmission levers 30 and bring them into position inactive, or in the active tripping position of the corresponding circuit breaker. The axis 46 and the tube 45 are biased in rotation anticlockwise in FIG. 5, by return springs 50 so as to maintain the receiving cranks 48, 48 ′ in support of the associated pushers 43 , 43 '. The return springs 50 are arranged in line with the bearings 47, the tube 45 then being extended by a sheath 51. The position of the receiving cranks 48, 48 ′ is representative of the position of the breaking contacts 52 of the associated circuit breaker, and in position when these contacts are closed, the receiving crank moves the associated rotary cam to a position for triggering the transmission lever 30.

The operation of the interlocking device is explained below, with reference to FIGS. 5 and 6, in which the parts 13 ′, 43 ′ and 48 ′ surrounded by a broken line are shown in the position they occupy in the first circuit breaker 11 ', while the other parts are shown in the position occupied in the second circuit breaker 11. In FIG. 5, the first circuit breaker 11' is open and the pusher 43 'is held by the crank 13', in a first position noted in FIG. 5. The mechanical connection constituted by the first receiving crank 48 ′, the tube 45 and the second rotary cam 49 makes this first position of the pusher 43 ′ correspond to a first position of the second rotary cam 49 releasing the associated rocker arm 31 and the transmission lever 30 placed in a first inactive position, allowing the normal opening and closing of the second circuit breaker 11. When closing or in the closed position of the first circuit breaker 11 ', shown in Figure 6, the crank 13' moves the pusher 43 'to the second lowered position by causing the rotation of the tube 45 clockwise to bring the second rotary cam 49 in a second active position for engaging the rocker arm 31 and sliding up the transmission lever 30 towards a release position actuating the latch 22 to release the latch 21. In this position, the second circuit breaker 11 is automatically triggered and any closing operation is impossible, the latch 21 not being blocked. This first mechanical connection comprising the tube 45 provides interlocking between the two circuit breakers 11 'and 11, so that when the first circuit breaker 11' is in the open position, the second circuit breaker can be opened or closed, but on the other hand in the event of closure of the first circuit breaker 11 ', the second circuit breaker 11 is necessarily open. The second mechanical connection which comprises the axis 46 ensures in a way identical a connection between the circuit breaker 11 and 11 ', so that in the open position of the second circuit breaker 11, the first circuit breaker 11' can be opened or closed, but on the other hand, in the closed position of the second circuit breaker 11, the first circuit breaker 11 'must be open.

This interlocking device is particularly simple, and it can be added to standard circuit breakers, without any particular constraint. The rocker arm 31 and the transmission lever 30 can be used for other functions, in particular for the pre-trip function described with reference to FIGS. 1 to 4.

The interlocking device is advantageously used for circuit breakers of the type represented in FIG. 10, forming inter alia the subject of the aforementioned European patent application, in which the breaking contacts 52 are arranged in contact bridge, mounted floating on a bar or a section of bar 53, integral with the cranks 13 of the mechanism 15. The hook 19 has on its edge a reset profile 54 arranged so as to make the reset position of the handle 16 coincide with its open position . An open circuit breaker is thus always ready to be closed, even if the associated circuit breaker has transmitted tripping orders by actuation of the transmission lever 30.

It is clear that the transmission system between the two circuit breakers can be achieved by two independent bars or by any other operating means.

Claims (7)

1. An electrical device comprising :

   - a first (11') and a second (11) circuit breaker with a moulded case (12) arranged side by side on the front of a fixing plate (41), each circuit breaker having :

   - a mechanism comprising a locking device with a locking bolt (21) and latch (22) and a handle able to occupy a first stable closed position of the circuit breaker, a second stable open position of the circuit breaker and an intermediate tripped position in the unset position of the mechanism following a tripping order;

   - a push-button (43, 43') with two stable positions, a first position representative of the open position of the circuit breaker and a second position representative of the closed position of the circuit breaker, said push-button protruding out from the rear faces of the moulded cases, and

   - a transmission lever (30) with two stable positions, a first inactive position and a second position commanding tripping of the locking device, said transmission lever protruding out from the rear faces of the moulded cases;

   - an interlocking mechanism located on the rear of the fixing plate (41) to prevent simultaneous closing of the two circuit breakers (11,11'), and comprising :

   - a first rotary bar (45) which cooperates at one of its ends, by means of a first crank (48'), with the push-button (43') of the first circuit breaker (11'), and at the other end with the transmission lever (30) of the second circuit breaker (11) to move the latter transmission lever (30) to said second position when said push-button (43') of the first circuit breaker (11') is in the second position,

   - a second rotary bar (46) which cooperates at one of its ends, by means of a second crank (48), with the push-button (43) of the second circuit breaker (11), and at the other end with the transmission lever (30') of the first circuit breaker (11') to move the latter transmission lever (30') to said second position when the push-button (43) of the second circuit breaker (11) is in the second position,

   characterized in that each of said first and second rotary bars (45, 46) comprises a cam (49, 49') arranged to cooperate with the corresponding transmission lever (30, 30') by means of a rocker (31) which rocker (31) is pivotally mounted on a spindle (34) securedly united to the moulded case and articulated on said transmission lever in question.
2. The device according to claim 1, characterized in that the cranks (48, 48') are receiver cranks which bear a housing recess suitable for receiving the end of the corresponding push-button.
3. The device according to one of the claims 1 or 2, characterized in that the two rotary bars (45, 46) are coaxial, at least one (45) of the bars being tubular to surround the other (46).
4. The device according to one of the claims 1 to 3, characterized in that the crank (48') of the first bar (45) moves appreciably in the same plane as the rotary cam (49') of the second bar (46) and vice-versa.
5. The device according to any one of the foregoing claims, characterized in that the rotary bars are mounted with rotation on the fixing plate (41) and are urged by springs (50) in the bearing direction of the cranks (48, 48') against the push-buttons (43, 43').
6. The device according to any one of the foregoing claims, characterized in that the push-button (43, 43') is inserted between the crank (48, 48') and the bar (53) bearing the contacts (52), or a crank (13) securedly united to the bar (53).
7. The device according to any one of the foregoing claims, characterized in that said circuit breakers are rack-out circuit breakers comprising rack-in connectors (24) arranged to cooperate with stationary rack-in contacts (26) securedly affixed to said fixing plate, and in that each rocker (31) bears a pin (36) designed to cooperate with a fixed cam (29) securedly united to the fixing plate (41) so as to pretrip the rack-out circuit breakers when rack-in and rack-out operations take place.

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