1 System for signalling an electrical defect in an isolating apparatus The present invention relates to a system for signalling an electrical defect in an isolating apparatus of the circuit breaker type. 5 More specifically, the system of the invention preferably indicates the occurrence of a differential defect in a circuit. The isolating apparatuses concerned by the invention usually comprise: - a mechanical release lock associated with at least one pair of respectively fixed and movable contacts, transmitting the displacement of 10 a control lever to each movable contact with a view to moving it between two stable positions, respectively bearing against and at a distance from a fixed contact; - a device for detecting the electrical defect; - an electromagnet triggered by the detection device, the core of which 15 electromagnet can move counter to return means; - a connecting member between the core of the electromagnet and the release lock, able to release it in the event of a defect detected by the electromagnet. The signalling system of the invention also comprises an indicator means 20 which signals the appearance of a defect and which moreover has to store the information until reset brcught about by operating the control lever. In order to improve security, the signalling system of the invention is mechanical instead of being electrical and operating in a manner dependent on a source of power from the electrical installation protected by the circuit breaker. 25 Such mechanical systems exist, and the patent FR-2 767 602 gives in particular one example of a structure comprising a means for keeping the indicator in a visible position counter to the action of a return means for returning it to an invisible position, so as to store the release action until an apparatus closing manoeuvre is carried out. 30 More specifically, the indicator return means comprises a slide which is entrained in translation by the control lever between a rest position and an 2 indicator retaining position. Such a system makes it necessary to shape the indicator, which in this case is mounted to rotate about a fixed axle of the apparatus, so that one of its ends cooperates with the slide. The latter is itself subjected to return means for returning it to a rest position in the absence of 5 defects. This mechanical system incorporates a plurality of components along a kinematic chain which involves simultaneously parts in rotation and parts in translation. The multiplication of the parts is not a favourable sign in terms of reliability of the assembly, and it also makes assembly of the apparatus more 10 complicated. On an economic level, these parameters can be seen as unfavourable. To overcome these drawbacks, the signalling system of the invention essentially comprises one movable part which groups together a plurality of functions. 15 More specifically, the signalling system of the invention, which can be applied to isolating apparatuses as described above, is characterised mainly in that it comprises a signalling part entrained by the core of the electromagnet and having a signalling surface able to move opposite a window formed in the facade of the apparatus and a stud provided for releasing the lock in the event of 20 displacement of the core upon detection of a defect by the detection and control device, a retaining relief and a corresponding recess being provided respectively on said signalling part and on the control lever or on a component secured thereto, the relative positmning thereof culminating in blocking the signalling part after displacement of the core brought about by the electromagnet, the lever 25 being in the open position of the contacts. Contrary to the solution of the prior art, according to which one or more parts were interposed between the signalling component and the lever, the system of the invention involves only a single part, which serves both for signalling and blocking, the latter being made possible by the existence of the 30 relief/recess pair.
3 More specifically, according to the invention, the relief may be a lug located on the signalling part and the recess may take the form of a cam located on the control lever or on a component secured thereto. An inverse configuration could of course also be used. 5 According to one possibility, said signalling part may be entrained in translation and may comprise an orifice for fixing it to the core of the electromagnet, a first radial arm comprising the release stud, a second axial arm comprising the blocking lug, and a plate extending parallel to the first arm and having the signalling surface. 10 This is therefore a part of complex shape which is slipped onto the end of the movable core of the electromagnet and the different arms of which perform separate functions. Thus, when the core moves towards the coil, the first arm strikes the release lock by way of the stud, causing it to trip and causing the contacts to open. During the displacement of the electromagnet, the second arm 15 is entrained parallel to the axis of the core, which moves the lug in rectilinear translation in the direction of the coil. So that this movement is possible, it is of course necessary that the second arm is offset relative to the axis of the core. Preferably, according to the invention, it extends from the first arm. 20 Alternatively, the signalling part may be entrained in rotation and may comprise according to one possibility a peripheral wall shaped as an arc of a circle delimited by two radial walls, one of which comprises an orifice for fixing it to the core of the electromagnet, the release stud being oriented parallel to the axis of rotation and protruding beyond the part at the other of the radial walls. 25 The end thereof moreover comprises a plate having the signalling surface, the blocking lug being provided on the periphery of the wall shaped as an arc of a circle. As indicated above, the lug cooperates with a cam fixed in rotation with the control lever. In reality, this cam is arranged at the periphery of a component 30 which is fixed to the control lever, and it consists of a protrusion positioned in such a way that, in the open position of the contacts, said protrusion interferes 4 with the trajectory of the retaining lug and blocks the return of the signalling part by the return means of the core, after detection of the defect. The cam places itself in the blocking position on account of the tripping of the lock, said tripping being obtained by the displacement of the signalling part. 5 When the return means act to return the core, and consequently said signalling part, to their initial position, the lug meets the protrusion of said cam and is therefore blocked. In this same position, the signalling surface is positioned in front of the window formed in the facade of the apparatus, and therefore indicates that the opening of the isolating apparatus results from a differential 10 defect signalled by the electromagnet of the differential stage. According to one possibility, the return means consist of a compression spring interposed between the yoke of the electromagnet and the signalling part fixed to the movable core. This spring in principle returns the assembly consisting of the signalling 15 part and the movable core into its stable initial position in the absence of any defect. As has been seen above, however, this spring performs its function correctly only if the control lever is not in the open position of the contacts. In other words, when the apparatus is reset, with a view to closing the contacts, the cam which is fixed in rotation with the control lever is moved out of the trajectory 20 of the signalling part, enabling the spring to perform its function and enabling the signalling part and the core to resume their initial position. The invention applies in particular to a differential circuit breaker, equipped with a signalling system as explained above, and which comprises a partition separating the circuit breaker part and the part performing the 25 differential function, said part moreover including the electromagnet. The partition is furthermore provided with an opening for the passage of the release stud of the signalling part, the component which has the cam and which is fixed to the lever being also arranged on the differential part side. The displacement of the signalling part leads, in the event of a defect and 30 on account of the existence of said opening, to the displacement of the stud in 5 translation, in the space occupied by the circuit breaker function, towards the release lock. The invention will now be described in greater detail with reference to the appended figures, in which: 5 - Fig. 1 shows, in perspective, a differential circuit breaker constituting one example of an isolating apparatus which can be equipped with a signalling system according to the invention; - Fig. 2 shows, in a perspective view, a signalling part according to the present invention; 10 - Fig. 3 is a partial perspective view of the differential circuit breaker of Fig. 1, showing in particular the cooperation between the electromagnet and a signalling part able to move in translation according to the invention; - Fig. 4 shows, in partial section, the relative position of the lever and of 15 said signalling part in the absence of any differential defect; - Fig. 5 shows once again the elements of the preceding figure, in the event of a differential defect occurring; - Fig. 6 is the equivalent of Fig. 3 with a rotational configuration of the signalling part; 20 - Fig. 7 shows the rotational signalling part in a perspective view; and - Figs. 8 and 9 are views similar to the views of Figs. 4 and 5 showing the respective positions of the rotational signalling part in the absence and in the presence of a differential defect. With reference to Fig. 1, the differential circuit breaker comprises a 25 housing (1) moulded from plastic and from which there protrudes a control lever (2), the two stable positions of which correspond respectively to the closing and to the opening of the contacts. Inlet and outlet connection means (3) and (4) make it possible to insert the differential circuit breaker into a circuit. The housing (1) therefore includes a 30 circuit breaker function and a differential defect detection function. The position of the control lever (2) shows that the circuit breaker part is located in the left- 6 hand half of the product, whereas the differential part is located in the right-hand half. The latter is equipped with a window (5), with which the signalling system of the invention cooperates. This system is based on a signalling part (6), one example of which is 5 shown in Fig. 2 in a version able to move in translation. It comprises an orifice (7) provided for fixing it to the movable core (see Fig. 3) of the electromagnet. A first arm (8) is oriented radially with respect to the orifice (7). At its end, there is a stud (9) serving to release the mechanical lock. A second arm (10) extends from the first arm (8), the free end of which second arm is equipped with a 10 triangular projection (11). The part (6) is moreover provided with a plate (12), the visible surface (13) of which is provided with a means for signalling a differential defect. With reference to Fig. 3, showing the housing (1) without its cover, the spaces devoted to the two functions, respectively the circuit breaker function 15 and the differential function which were mentioned above, are separated by a partition (14), to which there is fixed in particular an electromagnet (15) which conventionally consists of a coil (16), of a movable core (17) and of a magnetic yoke (18). The signalling part (6) of the invention is fixed to the end of the movable core (17), a compression spring (19) being interposed between the left 20 side wall of the magnetic yoke (18) and a collar (20) surrounding the orifice (7). The release stud (9), which is not visible in this figure, slides in an opening (21) formed in the partition (14). When a differential defect occurs, the core (17) penetrates into the coil (16), thereby displacing the whole part (6) and in particular the plate (12) and its 25 signalling surface (13). The latter is then displaced so as to be located opposite the window (5) formed in the facade of the housing of the differential circuit breaker, in the cover thereof (see Fig. 1). The information is stored, the plate (12) remaining in its position after the disappearance of the differential defect since the part (6) is retained in the 30 position corresponding to the penetration of the movable core (17) into the coil (16) by virtue of a cam (23) provided on the periphery of a component (22) fixed 7 in rotation with the control lever (2), and which protrudes from the differential side of the partition (14). This cam can be seen in Figs. 4 and 5. These figures show the part (6) and the control lever (2), and consequently the component (22), in a position 5 reflecting respectively the absence of detection of a differential defect and the presence of such a defect. In the configuration of Fig. 4, the position of the control lever (2) reflects the closing of the contacts. Under this hypothesis, the cam (23) is located close to the facade of the housing (1), and the entire part (6) is located at a distance from the coil, in the initial rest position. Under the 10 hypothesis of the appearance of a differential defect, the core (17) penetrates into the coil (16), entraining the part (6). The arm (10) and the projection (11) are consequently displaced in the direction of the arrow (F), towards the right in the figures. The displacement of the part (6) of course gives rise to a concomitant displacement of the radial arm (8) and of its release stud (9) into the window 15 (21). This displacement causes the release of the lock, which trips, and the simultaneous tripping of the control lever (2). The component (22) is thus entrained in rotation, along with the cam (23), which is in the position of Fig. 5. So that the system can function correctly, it is necessary that the displacement of the cam (23) takes place after the displacement of the 20 projection (11), but before the latter is returned to its initial position by the spring (19). The configuration of the invention allows this sequential functioning. The cam (23) interferes in this case with the trajectory of the projection (11) and retains the latter, preventing the return of the part (6) to the initial rest position under the effect of the return means, namely the spring (19). Under this 25 hypothesis, illustrated by Fig. 5, the signalling surface (13) is opposite the window (5), which is not the case in Fig. 4. The resetting of the product, carried out by the user by exerting a pressure on the lever (2) so as to cause it to move from its position in Fig. 5 to that of Fig. 4, causes the cam (23) to move into its position shown in Fig. 4. In 30 this case, there is no longer anything to oppose the action of the return means 8 (19), and the part (6) is returned to its original position. The signalling surface (13) is then no longer opposite the window (5). With reference to Figs. 6 to 9, a variant with a rotational configuration is based on a part (6') essentially comprising a wall (25) in the shape of an arc of a 5 circle, on which the blocking lug (11') is positioned, and two radial walls (26) and (27) delimiting the wall (25) in the shape of an arc of a circle, the first comprising an orifice (7') for fixing it to the core of the electromagnet while the second comprises the release stud (9'). The functioning, shown in Figs. 8 and 9, is depicted for a rotational 10 displacement compared to that shown in Figs. 4 and 5 for a translational displacement. In the absence of any differential defect, the part (6') is in the position shown in Fig. 8. The appearance of such a defect, causing the displacement of the core (17) of the electromagnet (15) in the direction of the arrow (F') as shown in Fig. 9, causes a rotation of the part (6') about the pivot 15 (28) and the displacement of the stud (9') in the window (21). This movement leads to the signalling surface (13') of the part (6') being placed opposite the window (5) formed in the facade of the housing (1). At the same time, the stud (9') brings about the release of the lock, the opening of the contacts, and the tripping of the lever (2) into the position shown in Fig. 9. 20 In this case, the cam (23) located on the periphery of the component (22) is displaced so as to block the return of the part (6'), since the lug (11') then strikes said cam (23) when the spring returns the core (17) to its initial position. The differential defect is thus stored until the lever (2) is manually switched into the closed position of the contacts. 25 The two examples illustrated by the figures are not to be considered as exhaustive of the invention, which on the contrary encompasses variant embodiments if they should fulfil the same functions.