Mechanical control device for an electrical switchgear with three switching positions, provided with a selection lever cooperating with a cam

A control device (10) for an electrical switchgear with three switching positions including a closed position, an open position and an earthing position. The switchgear includes a main shaft (14) and a drive shaft (28). The control device includes a mode selector lever (30) designed to select one operating mode among a motor driven switching mode, a manual switching mode between the open position and the closed position of the electrical switchgear, and a manual switching mode between the open position and the earthing position of the electrical switchgear. The mode selector lever has an opening with a curved contour, and the control device includes a cam disk (50) with a cam (54) capable of moving inside the opening (40). The control device may be applied to an isolating switch.

RELATED APPLICATION

The present document claims priority to French patent application serial No. 04 52679 filed Nov. 18, 2004, which is hereby incorporated herein by reference.

TECHNICAL FIELD

This invention relates to the technical domain of mechanical control devices for switchgears with three switching positions, namely a closed position, an open position and an earthing position.

More particularly, the invention relates to a mechanical control device for a shielded switchgear with gas insulation, for example like a gas-insulated circuit breaker or isolating switch with three switching positions. The mechanical control device can be used to actuate this switchgear electrically or manually.

BACKGROUND OF THE INVENTION

Documents EP 1 271 588-A1 and EP 1 271 589-A1 disclose control devices for an isolating switch with three switching positions comprising a closed position, an open position and an earthing position, through which the isolating switch may be electrically or manually activated. The control devices comprise a main rotary shaft that will be coupled to the mobile contact of the isolating switch. This mobile shaft is rotated during switching operations, either by an electric motor or manually through a crank that is then coupled with a manual switching member connected in movement to the main shaft.

More precisely, these documents describe control devices for a three-position isolating switch, comprising two manual switching members, one which switches the isolating switch from its closed position to its open position or vice versa, and the other that switches the isolating switch from its open position to its earthing position or vice versa.

EP 1 271 588-A1 describes an isolating switch control in which a mechanism is integrated preventing some manual switching sequences of the isolating switch to satisfy the particular requirements of a user.

EP 1 271 589-A1 describes an isolating switch control also comprising a means of locking the rotary movement of the crank when the isolating switch reaches its open position from its closed position or from its earthing position.

Isolating switch control devices described in these two documents have disadvantages.

Firstly, these isolating switch control devices comprise an interlocking mechanism, for which the arrangement and the configuration can prevent some manual switching sequences of the isolating switch. For example, it is impossible to perform an earthing operation following a closing operation.

Furthermore, these isolating switch control devices comprise two separate openings into which the crank can be inserted to switch manually between the closed position and the open position, or between the open position and the earthing position. Each opening is provided with a coupling part that will mechanically connect the stop bolt to the control and a closing member to prevent the crank from being inserted into the opening when the switch is in a position preventing the corresponding operation. Each of these two openings is also provided with at least one bolt. It is difficult and expensive to duplicate these parts.

Furthermore, the interlocking mechanism of these isolating switch control devices is controlled by a secondary shaft that is driven by the main shaft through a bevel gear. However, there is a risk that the interlocking mechanism is in a position that does not correspond to the position of the main shaft, which can cause unwanted manual operations.

Consequently, there is a need for a mechanical control device for a switchgear with three switching positions without the disadvantages in control devices mentioned above.

SUMMARY OF THE INVENTION

The purpose of the invention is to propose a control device for an electrical switchgear with three switching positions, for example like an isolating switch, which does not have the disadvantages mentioned above.

According to the invention, the control device for an electrical switchgear with three switching positions of the type comprising the closed position, an open position and an earthing position, and comprising a main shaft and a drive shaft, is designed to be coupled to a mobile contact of said electrical switchgear. It comprises:a mode selector lever designed to select one operating mode among the <<motor driven switching mode >>, the <<first manual switching mode between the open position and the closed position of the electrical switchgear>> and the <<second manual switching mode between the open position and the earthing position of the electrical switchgear >>, said mode selector lever comprising an opening, anda cam disk fixed on the drive shaft, with a cam capable of moving inside said opening,

such that the displacement of the cam disk is free when the control device is in the motor driven switching mode, limited to a first angular rotation range of the drive shaft when the control device is in the first manual switching mode, and limited to a second angular rotation range of the drive shaft when the control device is in the second manual switching mode.

The mode selector lever moves between:a neutral position in which the motor driven switching mode is selected, that may be reached for any angular position of the main shaft,a first extreme position, in which the first manual switching mode between the open position and the closed position of the electrical switchgear is selected, and that can be reached when the angular position of the main shaft is in a first angular range,a second extreme position, in which the second manual switching mode between the open position and the earthing position of the electrical switchgear is selected, and that can be reached when the angular position of the main shaft is in a second angular range.

The contour of the cam is substantially circular or elliptical or oval and has a centre of curvature that is coincident with the centre of curvature of the cam disk. It is connected to the cam disk by two connecting areas that define two circumferential noses.

The contour of the opening of the mode selector lever comprises two curved parts connected to each other by two intermediate portions, the curved portions and the intermediate portions being separated by connecting areas that define two connecting notches.

The control device comprises a transmission and interlocking disk fixed on the main shaft, said transmission and interlocking disk comprising a first part of the disk that is functionally connected to position indicating equipment, and a second part of the disk that cooperates with the mode selector lever to prevent it from being in the wrong position during displacement, as a function of the angular position of the main shaft.

The first part of the disk is fitted with teeth around its periphery, said teeth being designed to engage with the teeth in a control bar that is functionally connected to auxiliary switches and to a position indicator.

The second part of the disk comprises a slit substantially in the shape of two ring portions radially offset from each other and in communication with each other.

The connecting device comprises a spindle fixed to the mode selector lever that engages in said slit to prevent the mode selector lever from being in an incorrect position during its displacement as a function of the angular position of the main shaft.

The spindle extends substantially perpendicular from a face of the mode selector lever that is facing the transmission and interlocking disk.

The transmission and interlocking disk is driven by a driven disk supported on the main shaft, said driven disk itself being driven by a roller wheel fixed on the drive shaft, wherein the driven disk is provided with two recesses and two stop areas such that said driven disk and said roller wheel form a Geneva drive mechanism.

According to a first embodiment of the control device, the driven disk is rigidly fixed to the main shaft and drives the main shaft and the transmission and interlocking disk fixed on said main shaft.

According to a second embodiment of the control device, the driven disk has a degree of freedom in rotation about said main shaft and a degree of freedom in translation along said main shaft, the driven disk drives the transmission and interlocking disk, the driven disk being applied elastically in contact with the transmission and interlocking disk through a return means. Each of said driven disk and transmission and interlocking disk comprises corresponding holes that coincide so as to form cavities inside which balls are arranged. The combination of the transmission and interlocking disk, the driven disk, the return means, balls and holes forms a torque limiting mechanism.

In the same way as in the first embodiment and the second embodiment, rotation of the first cam disk is interrupted:either when the selector lever is in the first extreme position and the electrical switchgear is in the open position, since a first of the noses of the cam on the cam disk stops in contact with a first connecting notch of the opening in the mode selector lever,or when the mode selector lever is in the first extreme position and the electrical switchgear is in the closed position, since a first of the rollers of the wheel stops in contact with one of the stop areas of the driven disk during operation of the Geneva drive mechanism,or when the mode selector lever is in the second extreme position and the electrical switchgear is in the open position, since a second of the noses of the cam on the cam disk stops in contact with a second connecting notch of the opening of the mode selector lever,or when the mode selector lever is in the second extreme position and the electrical switchgear is in the earthing position, since a second of the rollers of the wheel stops in contact with the other of the stop areas of the driven disk during operation of the Geneva drive mechanism.

In the same way as in the first embodiment and the second embodiment, the control device comprises an actuation lever that is functionally connected to the mode selector lever, such that the motor driven switching mode or one of the two manual switching modes can be selected by positioning the actuation lever in one of the following three positions:a neutral position corresponding to the neutral position of the mode selector lever, through which the motor driven switching mode is selected,a first extreme position corresponding to the first extreme position of the mode selector lever, and through which the first manual switching mode between the open position and the closed position of the electrical switchgear is selected,a second extreme position corresponding to the first extreme position of the mode selector lever, and through which the second manual switching mode between the open position and the earthing position of the electrical switchgear is selected.

Displacement of the actuation lever causes displacement of a connecting rod that is connected to the mode selector lever and that controls displacement of the mode selector lever.

The actuation lever can pivot about a pivot shaft in a plane perpendicular to an auxiliary shaft.

The control device is functionally connected to a locking mechanism that comprises a locking lever rigidly fixed to the actuation lever and a stop bolt. The control device and the locking mechanism are arranged in a housing, such that the actuation lever and the stop bolt are arranged on the outside of a wall of said housing, while the locking lever is arranged on the inside of said wall of said housing.

The housing is also provided with a passage hole and the stop bolt is provided with a bolt stem. Subsequently:when the motor driven switching mode is selected, the locking lever is positioned facing the passage hole, so as to prevent the bolt stem or a manoeuvre member from coupling with the auxiliary shaft and enabling rotation of said auxiliary shaft, andwhen one of the manual switching modes is selected, the locking lever is positioned so as to release the passage hole, so that a bolt stem or a manoeuvre member can be coupled with the auxiliary shaft.

The stop bolt and the actuation lever are locked together in a position corresponding to the motor driven switching mode or in a position corresponding to either of the two manual switching modes, by means of a padlock with arms that pass through at least one locking hole in the actuation lever and at least one hole in the stop bolt. In this way, rotation of the auxiliary shaft is locked in one of the two manual switching modes.

Furthermore, the control device comprises at least one switching lever associated with the locking mechanism, said at least one switching lever being connected to additional switches themselves connected to the motor, to inform said motor about which switching mode is selected.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

The first embodiment of the control device according to the invention will now be described. Referring firstly toFIGS. 1 and 2, the figures show a control device10for an electrical switchgear with a mobile contact that can be switched in three positions corresponding to opening, closing and earthing of the electrical switchgear.

The control device10is arranged inside a housing12. It comprises a main rotating shaft14that will be coupled to the mobile contact (not shown) of the electrical switchgear.

In normal operation or motor driven switching mode, the main shaft14is driven by a motor2(shown inFIG. 2). This motor2is controlled by signals originating from auxiliary switches13and a master control equipment (not shown). The motor2stops operating as soon as one of the three positions of the electrical switchgear (open, closed or earthing) is reached.

More precisely, the control device10comprises a drive shaft28and an intermediate shaft68, both parallel to the main shaft14. The main shaft14supports a driven disk84driven by a wheel60supported on the drive shaft28. This wheel60has a toothed periphery and is itself driven by a set of gears4supported by the intermediate shaft68, this set of gears4being driven in rotation by the motor2.

The wheel60, visible inFIGS. 2 and 3, is rigidly fixed on the drive shaft28. It comprises two wheel rollers62,63, that are rigidly fixed on a face of the wheel, diametrically opposite to each other.

The driven disk84, shown in a top view inFIG. 12, is rigidly fixed onto the main shaft14. It is substantially in the shape of a half-disk with a diametral edge85. It is provided with two recesses86that are dimensioned and positioned such that each of them can hold one of the two wheel rollers62,63. It is also provided with two stop areas88, each being positioned between one of the recesses86and the diametral edge85. The contour of these stop areas88is substantially in the shape of the portion of a disk.

The wheel60and the driven disk84function together like a mechanism known as a <<Geneva drive mechanism>>. In other words, as the wheel60rotates, one or the other of the wheel rollers62,63engages with one of the recesses86of the driven disk84, and drives it in rotation along a path corresponding to a portion of a circle, and then it moves out of this recess86.

In some circumstances, for example in the case of a power failure or an emergency, it is desirable that instead of being rotated under control of the motor2, the main shaft14should be rotated under manual control.

To achieve this, the control device10may be used through a manoeuvre member that can be coupled to an auxiliary shaft106. The control device100is provided with an actuation lever112placed in a position corresponding to a manual switching mode. This actuation lever112is functionally connected to a mode selector lever30cooperating with a first cam disk50. The first cam disk50is supported by the drive shaft28that drives the main shaft14through the Geneva drive mechanism, in the same way as for the motor driven switching mode described above. The rotation movement of the main shaft14is limited by the first cam disk50cooperating with the mode selector lever30and by the stop areas88on the driven disk84cooperating with the rollers62,63of the wheel60. All these parts will be described with reference toFIGS. 2 to 4and8to11.

The actuation lever112shown inFIGS. 2 to 4is actuated manually by an operator. It comprises a body having a shape substantially like an elongated plate. It is arranged outside the housing12parallel to a face of the housing. One of its ends is fixed on a pivot shaft116such that the actuation lever112can pivot around the pivot shaft116in a plan perpendicular to said pivot shaft116.

As shown inFIG. 2, the angular displacement of the actuation lever112is defined inside an angular sector for which the limits define two extreme positions112-2and112-3, and the median of which defines a neutral position112-1.

The mode selector lever30is shown inFIGS. 2 and 4. It is substantially in the form of a plate with a substantially disk-like central body32with a first extension34prolonging the central body32and tapering substantially in the form of a triangle, and a second tail-like extension36prolonging the central body32. The two extensions34,36are diametrically on opposite sides of the central body32.

The end of the first extension34comprises a hole35through which a rotation rod38passes, itself rigidly fixed to the housing12, such that the mode selector lever30is free to rotate around this rotation rod38in a plane perpendicular to the main shaft14and to the drive shaft28.

The end of the second extension36is connected free to rotate to a first end of a connecting rod98itself functionally connected to the actuation lever112. When the connecting rod98acts on the end of the second extension36, the mode selector lever30is moved in rotation about the rotation rod38. As shown inFIG. 2, the angular displacement of the mode selector lever30is defined inside an angular sector, the limits of which define two extreme positions30-2and30-3, and the median of which defines a neutral position30-1.

The angular displacement of the mode selector lever30is triggered by a translation of the connecting rod98along the axial direction of the connecting rod, this translation itself being provoked by an angular displacement of the actuation lever112about its pivot shaft. Thus, the correspondence between the angular displacements of the actuation lever112and the mode selector lever30in the example shown on the figures, and more particularly inFIG. 2, is as follows:when the actuation lever112is in its neutral position112-1, the mode selector lever13is in its neutral position30-1, and the motor driven switching mode is selected,when the actuation lever112is in its first extreme position112-2, the mode selector lever30is in its first extreme position30-2to the right of the neutral position30-1inFIG. 2, and the first manual switching mode between the open position and the closed position of the electrical switchgear is selected,when the actuation lever112is in its second extreme position112-3, the mode selector lever30is in its second extreme position30-3to the left of the neutral position30-1inFIG. 2, and the second manual switching mode between the open position and the earthing position of the electrical switchgear is selected.

The mode selector lever30shown in a top view inFIG. 9is provided with an opening40formed in the substantially disk-shaped central body32. This opening40is a through opening in the example shown. It has a curved contour, with two curved portions42,43substantially following a portion of a circle or a portion of an ellipse or a portion of an oval or a combination of these shapes. The two curved portions are arranged with one facing the first triangular-shaped extension34and the other facing the second tail-like extension36. The two curved portions42,43are connected to each other through two intermediate portions44that extend inside the opening40so as to interrupt the circular or elliptical or oval line defined by the two curved portions. The two connecting areas between the two intermediate portions44and the curved portion43located facing the second extension36define connecting notches46in the contour of the opening40.

When the mode selector lever30is in the neutral30-1, the opening40is substantially centred about the drive shaft28.

The mode selector lever30also comprises a spindle48arranged on the intermediate portion44that is on the side of the main shaft14. This spindle48that can be seen inFIG. 5, extends substantially perpendicular to the central body32of the mode selector lever30, starting from one face of this lever.

The control device10also comprises a first cam disk50shown in a top view inFIG. 10, with a protuberance forming a cam54. The cam54has a substantially circular or elliptical contour with a centre of curvature coincident with the centre of curvature of the disk50. The two connecting areas between the contour of the disk50and the contour of the cam54define two circumferential noses56.

The first cam disk50is rigidly fixed to the drive shaft28facing the face of the wheel60on which the two wheel rollers62,63are located. The two circumferential noses56are arranged symmetrically on each side of the diameter of the wheel60on which the two wheel rollers62,63are placed.

The first cam disk50is substantially at the same level as the mode selector lever30with respect to the drive shaft28. The dimension of the first cam disk50, in other words the diameter of the disk plus the width of the cam54, is less than the largest dimension of the opening40. The result is that the opening40of the mode selector lever30surrounds the first cam disk50.

The transmission and interlocking disk16shown in a top view inFIG. 8is rigidly fixed to the main shaft14. It comprises a first disk part18with a toothed periphery that meshes with a first toothed linear part24of the control bar22, thus forming a bevel gear. The control bar22comprises a second toothed linear part25that meshes with the auxiliary switches13. One of the ends of the control bar22passes outside the housing12. A position indicator26is rigidly fixed to this end of the control bar22, so that it is visible outside the housing12.

The transmission and interlocking disk16comprises a second disk part20, not toothed, with a diameter greater than the diameter of the first disk part18.

In the example shown in the figures, the transmission and interlocking disk16is sized such that each of the two disk parts18,20corresponds substantially to half of the disk. The second part of the disk20comprises a through slit202substantially in the form of two ring portions radially offset from each other, and that are connected through a substantially straight intermediate portion in the radial direction. During operation, this slit202will hold the spindle48of the mode selector lever30.

The control device10also comprises a recessed disk72rigidly fixed to the main shaft14and cooperating with a roller lever76. This recessed disk72is shown in a top view inFIG. 11. It comprises three recesses74substantially in the shape of the portion of a circle opening up on its periphery. In the example shown, all three of the recesses74are in the same half of the recessed disk72.

The roller lever76that is entirely visible inFIG. 3, is substantially in the form of a rod with two elongated straight and parallel plates. One of the ends of the roller lever76is connected to the intermediate shaft68so that it can rotate freely about it. At the other of its ends, the roller lever78is fitted with a first roller78arranged between the two plates and free to rotate about an axis perpendicular to the two plates and connecting them together. Between its two ends, the roller lever76is provided with a second roller80arranged between the two plates and free to rotate about an axis perpendicular to the two plates and connecting them together. The rotation axes of the two rollers78,80are perpendicular to the direction of the roller lever76. The second roller80cooperates with a second cam disk82supported on the drive shaft28and with a return spring83that acts to hold the second roller80in contact with the second cam disk82. The second cam disk82is substantially in the shape of a rectangle with rounded corners, such that when the second roller80moves in contact with the second cam disk82, the roller lever76is driven by an angular movement about the intermediate shaft68. The length of the roller lever76, the diameters and positions of the first and second rollers78,80are such that the first roller78can engage with one of the recesses74of the recessed disk72and move out of it during movement of the roller lever76.

In the example shown in the figures, the driven disk84is arranged between the transmission and interlocking disk16and the recessed disk72along the main shaft14. The driven disk84, which is in the form of a half-disk, is arranged so that it is substantially facing the second part of the disk20of the transmission and interlocking disk16. A compression spring90pushes the driven disk84in contact with the transmission and interlocking disk16so as to maintain contact between these two disks (FIG. 3). The presence of this compression spring90is optional for the first embodiment, to the extent that the two disks16,84are rigidly fixed to the main shaft14.

Now will be described operation of the control device10according to the first embodiment, with reference toFIGS. 2,2A,3and4.

We will denote the first angular rotation range of the first cam disk50as the angular range denoted by50-1inFIG. 2A, and the second angular rotation range of the first cam disk50as the angular range denoted by50-2inFIG. 2A.

As mentioned above, when the actuation lever112is manually positioned in its neutral position112-1, the mode selector lever is in its neutral position30-1, and the motor driven switching mode of the electrical switchgear is selected. The motor2drives the set of gears4that drives the wheel60of the Geneva drive mechanism. The drive shaft28is fixed to this wheel60. Consequently, the first cam disk50rigidly fixed to the drive shaft28is rotated at the same time as the wheel60. This first cam disk is free to rotate, the cam54being free to rotate inside the opening40of the mode selector lever30for the neutral position30-1of this lever. Secondly, during rotation of the wheel60, one of the rollers62,63of this wheel60engages with one of the recesses86in the driven disk84. Consequently, the driven disk84is driven in rotation, together with the main shaft14to which it is rigidly fixed.

The operator can decide to position the actuation lever112manually in its first extreme position112-2or in its second extreme position112-3. In this case, a manoeuvre member for example such as a crank, may be coupled with an auxiliary shaft106that then drives the set of gears4in a manner similar to how this set of gears4is driven by the motor2when motor driven switching mode is selected.

When the actuation lever112is in its first extreme position112-2or in its second extreme position112-3, the mode selector lever30is in its first extreme position30-2or its second extreme position30-3respectively, and one of the two manual switching modes of the electrical switchgear is selected. These two situations are described below.

When the mode selector lever30is in the first extreme position30-2, the first manual switching mode is selected corresponding to switching between the open position and the closed position of the electrical switchgear.

The drive shaft28rotates. It lifts the roller lever76. It drives the first cam disk50in rotation and this cam disk rotates through approximately 200 degrees within the first angular rotation range50-1of the cam disk50, which corresponds to a rotation of substantially 60 degrees of the main shaft14. The electrical switchgear is then in the open position or in the closed position or in an intermediate position between the two. This angular range50-1is bounded on each side:firstly, rotation of the first cam disk50is interrupted when the electrical switchgear is in the open position, since a first of the noses56of the cam54stops in contact with a first of the connecting notches46of the opening40of the mode selector lever30,secondly, rotation of the first cam disk50is interrupted when the electrical switchgear is in the closed position, even if this first cam disk50could rotate by about another 20 degrees in this direction, since one of the rollers62,63of the wheel60stops in contact with one of the stop areas88of the driven disk84during operation of the Geneva drive mechanism.

When the motor selector lever30is in the second extreme position30-3, the second manual switching mode is selected, corresponding to switching between the open position and the earthing position of the electrical switchgear.

The drive shaft28rotates. It lifts the roller lever76. It drives the first cam disk50in rotation that rotates through approximately 200 degrees within the second angular rotation range50-2of the cam disk50, corresponding to a rotation of the main shaft14equal to about 60 degrees. The electrical switchgear is then in the open position or in the earthing position or in an intermediate position between the two. The angular range50-2is bounded on each side:firstly, rotation of the first cam disk50is interrupted when the electrical switchgear is in the open position, since a second of the noses56of the cam54stops in contact with a second of the connecting notches46of the opening40of the mode selector lever30,secondly, rotation of the first cam disk50is interrupted when the electrical switchgear is in the earthing position, even if this first cam disk50could rotate by about another 20 degrees in this direction, since a second of the rollers62,63of the wheel60stops in contact with one of the stop areas88of the driven disk84during operation of the Geneva drive mechanism.

The following characteristics must be recorded in each of the two situations that have just been described, namely manual switching mode from the open position to the closed position of the electrical switchgear and manual switching mode from the open position to the earthing position of the electrical switchgear.

Firstly, when one of the rollers62,63of the wheel60stops in contact with one or the other of the stop areas88of the driven disk84, the roller78of the roller lever76engages with one of the recesses74in the recessed disk72, to prevent free rotation of the main shaft14, since neither of the two rollers62,63of the wheel60is then engaged in one of the recesses86in the driven disk84.

The angular position of the two connecting notches46of the opening40in the mode selector lever30controls operation of the Geneva drive mechanism consisting of the wheel60and the driven disk84. This angular position of the connecting notches46is chosen such that rotation of the cam disk50is interrupted in both of the angular ranges50-1and50-2, by one of the noses56engaging in one of the connecting notches46just before one of the two rollers62,63of the wheel60comes into contact with one of the recesses86of the driven disk84. In this way, the Geneva drive mechanism is stopped if the main shaft14is in its neutral position. The electrical switchgear is then in its open position.

The shape of these connecting notches46is also chosen such that when rotation of the first cam disk50is interrupted by one of the noses56engaging with one of the connecting notches46, the resulting force is in the direction towards the centre of the hole35of the mode selector lever30.

Finally, the transmission and interlocking disk16is intended to limit rotation of the mode selector lever30so that it cannot be incorrectly positioned when it is moved manually by an operator using the actuation lever112and the connecting rod98. In other words, the mode selector lever30cannot be moved towards its first extreme position30-2unless the mobile contact of the electrical switchgear is in the open position or in the closed position or in an intermediate position between the two. Similarly, the mode selector lever30cannot be moved towards its second extreme position30-3unless the mobile contact of the electrical switchgear is in the open position or in the earthing position or in an intermediate position between the two. This displacement of the mode selector lever30is limited by means of the spindle48that extends from the face of the mode selector lever facing the transmission and interlocking disk16, and that moves in the slit202in this transmission and interlocking disk16during displacement of the mode selector lever30. When the mode selector lever30is in its neutral position30-1, the spindle48slides in the intermediate straight portion of the slit202. When the mode selector lever30is between its neutral position30-1and its first extreme position30-2, the spindle48slides in one of the ring portions of the slit202. And when the mode selector lever30is between its neutral position30-1and its second extreme position30-3, the spindle48is in the other of the ring portions of the slit202. The dimensions of the slit202are chosen to enable such displacement of the spindle48.

Now will be described the second embodiment of the control device10′ according to the invention with reference toFIG. 5, which is a sectional and elevation view of the control device10′. In particular, like the control device10according to the first embodiment, this control device comprises a main shaft14, a drive shaft28parallel to the main shaft14, a mode selector lever30acting on a first cam disk50fixed to the drive shaft28, a Geneva drive mechanism consisting of a wheel60with two rollers62,63and a driven disk84′.

The control device10′ according to the second embodiment is different from the control device10according to the first embodiment in that the driven disk84′ is not rigidly fixed to the main shaft14, but has a degree of freedom in rotation about this main shaft14, and a degree of freedom in translation along the main shaft14.

The control device10′ according to the second embodiment is also different from the control device10according to the first embodiment in that the transmission and interlocking disk16′ is provided with interlocking holes150on its face facing the driven disk84′, the holes opening up on said face and having a substantially cylindrical shape, and inside which balls152are placed. The depth of the interlocking holes150is such that the balls152project from the transmission and interlocking disk16′.

The control device10′ according to the second embodiment is also different from the control device10according to the first embodiment in that the driven disk84′ is provided with driven holes154on its face facing the transmission and interlocking disk16′, the holes opening up on said face and having a substantially cylindrical shape, their diameter being significantly less than the diameter of the interlocking holes150.

The interlocking holes150of the transmission and interlocking disk16′ and the driven holes154of the driven disk84′ are positioned such that they can be located facing each other for a given relative angular position of the transmission and interlocking disk16′ and the driven disk84′. A compression spring90pushes the driven disk84′ into contact with the transmission and interlocking disk16′. The compression force of the compression spring90is calibrated for a given torque.

According to one preferred embodiment, there are eight interlocking holes150, eight balls152and eight driven holes154.

Therefore according to this second embodiment, the torque is transmitted directly from this driven disk84′ to the transmission and interlocking disk16′, instead of being transmitted through the main shaft14. The driven disk84′ is applied in contact with the transmission and interlocking disk16′ by the compression spring90forming the return means. Thus, the presence of balls152trapped in the cavities formed by the driven holes150and the interlocking holes154provides a means of fixing the transmission and interlocking disk16′ and the driven disk84′ together.

In the case of a malfunction, for example if the mobile contact of the electrical switchgear is locked, the torque transmitted from the driven disk84′ to the transmission and interlocking disk16′ exceeds the value of the torque corresponding to the compression force of the compression spring90, which then no longer applies the driven disk84′ in contact with the transmission and interlocking disk16. The driven disk84′ moves in the axial direction along the main shaft14moving away from the transmission and interlocking disk16′, and the balls152move out of the driven holes154of the driven disk84′. This results in decoupling between the driven disk84′ and the transmission and interlocking disk16.

With this arrangement, the elements that control or indicate the position of the isolating switch, in other words the position indicator26, the slit202in the transmission and interlocking disk16′ and the auxiliary switches13can be in an appropriate switching position of the electrical switchgear, even in the case of a malfunction.

Furthermore, this arrangement satisfies the requirements of IEC (International Electrotechnical Commission) standard No. 129, according to which the weakest element of the kinematic chain starting from the motor as far as the mobile contact, must be located between the motor and the position indicator elements.

The transmission and interlocking disk16′ that has just been described with reference to the second embodiment of the control device10′, like the first embodiment, has functions to drive the position indicator26by means of the first toothed part of the disk18, and the function to limit the displacement of the mode selector lever30by means of the slit202. It also performs the function of a torque limiter, by means of the balls152. This torque limiter is arranged close to the Geneva drive mechanism.

We will now describe the locking mechanism100with reference toFIGS. 2,3,4,6and7. Although the locking mechanism100is only shown on the figures with the first embodiment of the control device10, it can also be used with the second embodiment of the control device10′.

The locking mechanism100is actuated manually. It is designed to prevent manual switching modes when the motor driven switching mode is used and to prevent motor driven switching mode when one of the two manual switching modes is used. The configuration of the control device10,10′ and the locking mechanism100assembly is such that the mode selector lever30is located between the main shaft14and the locking mechanism100.

The locking mechanism100comprises a plate102fixed on a sidewall of the housing12.

A passage hole104is drilled in the plate102. An auxiliary shaft106is arranged inside the housing102such that one of its ends is facing the passage hole104at a certain distance from it. The direction of the auxiliary shaft106is substantially perpendicular to the direction of the main shaft14. At its other end, the auxiliary shaft106is slid inside a support108in which it can rotate about its own axis.

An axle hole110is also drilled in the plate102, positioned such that the straight line between the passage hole104and the axle hole110is substantially parallel to the direction of the main shaft14in the example shown. Firstly the actuation lever112, then a locking lever114and two switching levers142are fixed on the pivot shaft116that passes through the shaft hole110such that the plate102is inserted between the actuation lever112and the locking lever114. Thus, the actuation lever112and the locking lever114can pivot together about the pivot shaft116parallel to and on each side of the plate102.

The locking lever114is connected to the second end of the connecting rod98, the other end of the connecting rod98being connected to the mode selector lever30as described above. Thus, pivoting of the locking lever114causes translation of the connecting rod98along the axial direction of the connecting rod, substantially perpendicular to the straight line between the passage hole104and the axle hole110and to the direction of the main shaft14. Thus, the actuation lever112is functionally connected to the mode selector lever30so as to control displacement of the mode selector lever. The actuation lever112is moved manually. When the actuation lever112is moved from its neutral position112-1to its first extreme position112-2, the mode selector lever30is moved from its neutral position30-1to its first extreme position30-2. Similarly, when the actuation lever112is moved from its neutral position112-1to its second extreme position112-3, the mode selector lever30is moved from its neutral position30-1to its second extreme position30-3.

The actuation lever112is substantially in the shape of an elongated plate. A lever hole118is drilled in its free end with a diameter substantially equal to the diameter of the passage hole104. It also comprises two extension tabs120extending at its free end, substantially perpendicular to the plane of the elongated plate, on the same side of this plate. When the actuation lever112is installed with one of its faces facing the plate102, the two extension tabs120are located on the face opposite this face facing the plate102.

A locking hole122is drilled in each of the two extension tabs120, these two locking holes122being arranged facing each other along a direction perpendicular to the direction of the elongated plate (FIG. 7).

The locking mechanism100also comprises a stop bolt130with a bolt head132and a bolt stem134. In the example shown, the bolt head132and the bolt stem134are substantially cylindrical in shape with circular sections centred on the same axle. The diameter of the bolt head132is sufficiently small so that the bolt head132can be placed between the two extension tabs120of the actuation lever112. The diameter of the bolt head132is sufficiently large so that the bolt head132cannot pass through the passage hole104.

The bolt stem134is hollow, and it can engage on the free end of the auxiliary shaft106, passing through the passage hole104and moving along the distance separating the free end of the auxiliary shaft106from the plate102, for some positions of the actuation lever112, as will be explained later. The end of the bolt stem134comprises two notches136, arranged so as to be diametrically opposite each other, that will cooperate with two pins107arranged on the free end of the auxiliary shaft106, being diametrically opposite each other. Consequently, when the bolt stem134is engaged on the free end of the auxiliary shaft106, the notches136and the pins107form locking means that fix the stop bolt130and the auxiliary shaft106together (FIGS. 6 and 7). Consequently, the auxiliary shaft106is prevented from turning when the stop bolt130is immobilised, for example by a padlock140.

The bolt head132comprises one or several stop bolt holes138(two in example shown). These stop bolt holes138are parallel to each other and pass diametrically through the bolt head132, in other words perpendicular to the direction of the bolt stem134(FIG. 7).

The stop bolt hole(s)138and the locking holes122will contain the arms of a padlock140, or a similar interlocking means, to interlock the stop bolt130and the actuation lever112, in one of the three possible positions112-1,112-2,112-3of the actuation lever112(FIG. 2).

Furthermore, the free end of each switching lever142is connected to additional switches144, for example of the microswitch type (seeFIG. 3) that are themselves connected to the motor and supply information to it about the selected mode, so as to cut off the power supply from the motor if one of the two manual switching modes is selected.

Now will be described operation of the locking mechanism100operating with the control device, and with reference toFIGS. 2,3,4and6.

FIGS. 2 and 3show the control mechanism10and the locking mechanism100assembly, in a configuration corresponding to the motor driven switching mode. The actuation lever112is in its neutral position112-1. It is positioned such that the lever hole118is facing the passage hole104. The bolt stem134is positioned such that it passes successively through the lever hole118between the two extension tabs120and penetrates into the passage hole104. When in its position, the locking lever114closes off the passage hole104such that the bolt stem134stops in contact with the locking lever114without being able to pass through the passage hole104. Consequently, the bolt stem134does not engage on the free end of the auxiliary shaft106. Therefore the auxiliary shaft106is free to turn, driven by the motor2. The padlock140is installed (FIG. 3) so as to immobilise the locking mechanism100in this position, each arm of the padlock140being positioned in one of the stop bolt holes138. The presence of the stop bolt130when positioned in this manner prevents the actuation lever112from pivoting towards one of the two extreme positions112-2,112-3. The locking lever114is then positioned in the same way as the actuation lever112, on the other side of the plate102. In this configuration, the connecting rod98is positioned such that the mode selector lever30connected to the first end of the connecting rod98is in its neutral position30-1, and the motor driven switching mode of the electrical switchgear is selected.

FIG. 4shows the control mechanism10and the locking mechanism100, in a configuration corresponding to the second manual switching mode between the open position and the earthing position of the electrical switchgear. The actuation lever112is in its second extreme position112-3. It is positioned such that the lever hole118is not facing the passage hole104, but is at its left inFIG. 4. The bolt stem134is positioned such that it passes only through the passage hole104, without passing through the thickness of the actuation lever112. The bolt head132is placed directly in contact with the plate102. Consequently, the bolt stem134is long enough so that it can engage on the free end of the auxiliary shaft106, the notches136being engaged with the pins107. The padlock140is installed so as to immobilize the locking mechanism100in this configuration, and to immobilize the auxiliary shaft106and the motor2to prevent accidental operation of the control device10. One of the arms of the padlock140passes through the stop bolt hole138furthest from the plate102and one of the extension tabs120, and the other arm of the padlock140does not pass through any part. The locking lever114is positioned in the same way as the actuation lever112, on the other side of the plate102. In this configuration, the connecting rod98is positioned such that the mode selector lever30connected to the first end of the connecting rod98is in its second extreme position30-3, and the second manual switching mode between the open position and the earthing position of the electrical switchgear is selected.

To use the control device10manually, the padlock140and the stop bolt130are removed and a manoeuvre member, not shown, may be coupled to the auxiliary shaft106. This manoeuvre member, for example a crank, is inserted into the passage hole104and is coupled to the auxiliary shaft106that then drives the set of gears4.

FIG. 6shows the locking mechanism100in a configuration corresponding to the first manual switching mode between the open position and the closed position of the electrical switchgear. The actuation lever112is in its first extreme position112-2. It is positioned such that the lever hole118is not facing the passage hole104, but is on its right inFIG. 6. The bolt stem134is positioned such that it passes only through the passage hole104without having to pass through the thickness of the actuation lever112. The bolt head132is placed directly in contact with the plate102. Consequently, the bolt stem134is long enough so that it can engage on the free end of the auxiliary shaft106, the notches136being engaged with the pins107. The padlock140is not shown, but it can be installed in a manner similar to that shown inFIG. 4, so as to immobilize the locking mechanism100in this configuration and to immobilize the auxiliary shaft106and the motor2to prevent any accidental operation of the control device10. The locking lever114is positioned in the same way as the actuation lever112, on the other side of the plate102. In this configuration, the connecting rod98is positioned such that the mode selector lever30connected to the first end of the connecting rod98is in its first extreme position30-2, and the first manual switching mode between the open position and the closed position of the electrical switchgear is selected.

Of course, the invention is not limited to the embodiment that has just been described. Variant embodiments performing the same functions could also be considered.

For example, the opening40is a through opening, but it could be replaced by a recess on the lower face of the mode selector lever30.

For example, there are two switching levers142, but there could be a single lever or they could be three or more.

Furthermore, the locking mechanism100and the auxiliary shaft106could be arranged with a different orientation, for example the auxiliary shaft106could be parallel to the main shaft14and to the drive shaft28.