EP2842143B1 - Control of spring(s) type for a high- or medium-voltage breaker furnished with a pawled free wheel coupling device - Google Patents

Description

TECHNICAL AREA

The invention also relates to an actuator also referred to as a spring energy storage type control (s), commonly referred to as a spring drive (s), a switch comprising a freewheel coupling device.

It is particularly applicable to high or medium voltage switches and more particularly to high or medium voltage circuit breakers used either for those used in gas insulated stations (GIS for short) or those used in isolation at commonly known as Dead-tank or Live-tank.

PRIOR ART

Already known from the prior art are freewheel coupling devices, in particular those with ratchets which consist, in general, of a ratchet wheel provided with teeth inclined so that in one direction said teeth raise at least a pawl mounted on a driven member which can thus continue to rotate freely, while in the other direction the wheel is immobilized against the (s) pawl (s) and is thus coupled in rotation with the driven member.

For example, the patent application DE3320242 which discloses such a ratchet freewheel coupling device for a timer. In this application, at the rotational torques considered, the ratchet wheel 3 drives in a direction G a ring 1 arranged coaxially around the wheel and in the other direction V the ratchet wheel 3 does not drive the ring 1, c that is to say that it works in freewheel. More specifically, the ratchet wheel 3 comprises a central portion to which three identical flexible arms 4, 5, 6 are connected by being symmetrically arranged around. Each end of arms 4, 5, 6 is provided with a finger 7, 8, 9 in the form of an asymmetrical pointed tooth 13, 14 with respect to the radius of the wheel 3. A pawl is thus formed both by an arm 4 , 5, 6 and its corresponding finger 7, 8, 9. The dissymmetry of each finger 13, 14 in the form of a pointed tooth is such that one of its flanks 13 is parallel to an edge 2 'of each tooth 2 of the outer ring 1, whereas the other side 14 is inclined by an angle with respect to the edge 2 "of each tooth 2 of the ring 1.

Thus, the parallel alignment of the flank 13 with the tooth edge 2 'prevents any relative displacement between them in the direction of rotation G of the wheel 3 at the envisaged torques for it. By against the inclination between the flank 14 with the tooth edge 2 "allows relative movement between them in the direction of rotation V of the wheel 3, that is to say the freewheel operation.

As mentioned by the patent itself, it is still possible to envisage in operation in free wheel of the ratchet wheel 3 in the direction G provided that it applies a much higher torque to the latter. Also, it is not possible to envisage using the ratchet coupling device according to this patent. DE 3320242 in a high-voltage circuit-breaker spring control because doing so would be tantamount to uncontrollably discharging the spring (s) so that it would no longer be possible to charge them again. In other words, it is not conceivable to apply the clutch freewheel coupling device according to the patent DE 3320242 in a high voltage circuit breaker spring control.

Also known from the prior art are spring type (s) controls of high voltage electrical switches, such as circuit breakers, which include a freewheel coupling device.

The spring-type high or medium voltage switch (s) typically include a hand crank or motor that can be used to charge, via a gear train, an opening or spring spring. closure whose release allows to bring or remove at least one moving contact to the other contact, and thus to open or close the switch. In other words, the spring is arranged in the control, so that the release of the elastic energy that it has stored causes the opening or closing of the contacts of the switch.

The freewheel coupling device is thus provided for coupling a drive wheel of the gear train and the crank or motor so that the wheel reaches the speed of rotation of the engine or crank. When the spring is loaded, the crank or motor drives the drive wheel to the top dead center of the spring.

When it comes for example to a closing spring to close the switch, the spring drives the drive element further downstream at a much greater speed than that obtained by the motor drive or crank . When this closing of the switch by the closing spring, the crank or the motor is uncoupled from the gear train via the freewheel coupling device, firstly to protect the motor mechanically when this is used and the gear and on the other hand to reduce the inertia of the elements driven by the spring. Indeed, the large accelerations and speeds put into play through the gear train during closing may cause premature wear of at least some parts of the engine and the gear. In each case (during loading of the closing spring and during the closing operation), the direction of rotation of the most downstream driving element is always the same.

This makes it possible to recover energy from the system back into the closing spring. Recovery reduces the spring arming time and the energy to be supplied by the motor (crank). During a closing operation, after a specific angle of rotation of the most downstream driving element has been reached, the motor can be started. In a first phase, the downstream drive element has a higher rotation speed than when it is driven by the motor, the freewheel coupling device is uncoupled, the drive element the most downstream and the motor rotate freely. In a second phase, when enough energy has been recovered by returning to the closing spring, the driving element has slowed down to a lower rotational speed than when it is controlled by the motor. But in this second phase, the freewheel coupling device mates and the motor controls the drive wheel for a complete reset of the closing spring.

In other words, the freewheel coupling devices are used in the high or medium voltage circuit breaker spring controls to allow the discharge of the spring (s) to open or close the circuit breaker contacts without have a torque applied to the crank or the motor. These freewheel coupling devices are thus imperative first for reasons of safety: in fact, under no circumstances should an operator be injured by an inadvertent and uncontrolled rotation of a crank.

In addition, without the use of such freewheel coupling devices, any opening and closing of the circuit breaker contacts could be delayed due to the rotational inertia of the crank and / or the motor during spring unloading.

It is known from the document DE 195 03 679 a high voltage circuit breaker spring drive in which a freewheel bearing is arranged between the last gear wheel of a loading gear and the gear connected to the drive wheel coupled to the closing spring thus loaded. The torque is transmitted only in the direction of the gear to the closing spring. The type of freewheel bearing is not specified.

The document EP 1 408 522 discloses a high voltage circuit breaker spring drive comprising a freewheel coupling device which consists of a conical clutch. Thanks to this conical clutch, there is transmission of a torque from a motor shaft to a rotary shaft in a predetermined direction of rotational movement between the two shafts and freewheeling operation of the rotary shaft in a direction opposite to the movement rotating between the two trees.

These spring-loaded switches with existing freewheel coupling devices are not completely satisfactory: they can thus be designed with a large number of parts and therefore have a significant cost and / or complicated control of the friction parameters.

Requirement WO2008 / 117437 discloses a spring-loaded control for a high-voltage switchgear comprising a motor 3 for charging a spring of closing 22 (compression coil spring) to which it is coupled via a set of three wheels, namely an output gear wheel 16 of the engine, an intermediate gear 33, 43 in permanent engagement with the output wheel 16 and a primary gear 5 arranged coaxially with the drive shaft 1 of the movable switch contact and incorporating a freewheeling coupling device for disengagement with the intermediate wheel 33, 43 as explained below. More exactly, as best represented in figure 3 the primary wheel comprises a set of three pinions A, B, C arranged side by side and coaxially with the drive shaft 1 of the movable switch contact, in which the center pinion B is provided with teeth over its entire length. external periphery while the two pinions A, C end are toothless on a circular peripheral zone, respectively 34a, 34b, the rest of their outer periphery being provided with teeth. The pinion C end arranged closest to the switch is provided on its inner periphery two pawls 41a, 41b arranged diametrically opposite to each other and mounted to move in translation according to the diameter of the pinion C. These pawls are complementary shapes with the beveled teeth formed on the entire inner periphery 36 of the pinion A of the center. The closing spring 22 is fixed directly to the pinion A via a pin 7 and an arm 8 forming the compression arm of the spring 22.

The operation of the control with its freewheel coupling device according to this application WO2008 / 117437 is the following: to load (compress) the closing spring 22, the motor 3 is engaged and rotates its output gear wheel 16 in the clockwise direction. The intermediate gearwheel 33 in permanent meshing is then driven in the counter-clockwise direction and simultaneously the primary gearwheel 5 in the clockwise direction, the clockwise and counterclockwise directions being defined in front view according to the figures of the patent application. . When the closing spring 22 is fully loaded, that is to say when its top dead center is reached, the peripheral zone of the pinion A reached at the meshing portion 43 of the intermediate wheel is the circular zone 34. without teeth. Thus, in this rotational position, the intermediate wheel 33 in permanent engagement with the output wheel 16 of the motor 3 continues to rotate without driving the pinion A.

In other words, the circular zone 34 without teeth of the pinion A allows the uncoupling between the motor 3 and the pinion A itself secured to the closing spring 22, thereby preventing any damage to the motor 3 in case of sudden stop. It is the same with the gear C whose toothless circular area 34b with respect to the circular zone without teeth 34a of the pinion A also allows uncoupling with the engine 3. By cons, because of its teeth on its entire outer periphery , pinion B continues to rotate. When loading the closing spring 22, the two pawls 41a, 41b of the pinion C are engaged in the internal teeth 36 of the pinion B. Consequently, the pinion B rotates simultaneously in the clockwise direction with the pinion C. When unloading the closing spring 22 to close the switch of the high-voltage switchgear the pinions A and C rotate simultaneously clockwise, the pawls 41a, 41b of the pinion B in engagement with the teeth 36 of the pinion B thus allow the coupling again to rotation of the three pinions A, B, C.

The major disadvantage of the closing spring control according to this application WO 2008/117437 is that the closing operation is slowed by the inertia of the rotating parts, namely the pinions A, B, C with the pawls 41a, 41b and the intermediate wheel 33 and the motor. In addition, the coupling device disclosed according to this application WO 2008/117437 can not be implemented in a crank-loading control, because due to the continuous drive of the input wheel 16, there would necessarily be a risk of driving the crank.

The patent US4491709 discloses a spring loaded control for use in a circuit breaker for short-circuit currents from 85kA to 600V or from 100 to 150kA to 480V. The spring-loaded control according to this patent makes it possible to load a closing spring 70 (compression coil spring) either by means of an actuating handle 98 or by means of a motor 180, the unloading of the spring making it possible to close the movable contact 26 on the fixed contact of the breaker. This control comprises a set of ratchet wheels 178 including an annular ratchet wheel 188 with teeth 190 over its entire outer periphery and teeth 194 over its entire inner periphery. This control also comprises two completely separate control mechanisms with the first comprising the actuating handle 98 for manually controlling the rotation of the ratchet wheel 188 and the second comprising the motor 180 for controlling the rotation of the ratchet wheel 188. first mechanism comprises firstly a stop pawl (anti-return) 201 mounted at the peripheral proximity of the ratchet wheel 188 and whose function is to prevent it from rotating in a clockwise direction. A push rod 182 is connected to another connecting rod 186 and can push another pawl 192 also mounted at the peripheral proximity of the ratchet wheel 188. The actuation of this other pawl 192 allows the rotation of the wheel ratchet 188 in a counterclockwise direction in front view of Figure 4G, when the connecting rod 186 is manually operated. Thanks to the non-return ratchet 201 the ratchet wheel 188 can not apply a torque to the connecting rod 186. As illustrated in FIG. 4J of this patent US 4491709 the second mechanism comprises three pawls 202 mounted at 120 ° to each other on the shaft 166 and in meshing with the teeth 194 at the inner periphery of the ratchet wheel 188. On the shaft 166 is fixedly mounted a pinion 206 which is connected to a motor 180 by means of another pinion 210. Thus, the motor pinion 206 rotates the three pawls 202 in a anti-clockwise in front view according to Figure 4J, so that they engage in the teeth 194 of the inner periphery of the ratchet wheel 188.

Due to the mounting of the pawl 192, the rotational drive of the ratchet wheel 188 allows the rotation of the three pawls 202 counterclockwise (Figure 4J) but does not cause the actuation of said pawl 192. In other words in the anti-clockwise direction in front of FIG. 4J, the pawl 192 does not mesh with the teeth 190 at the outer periphery of the ratchet wheel 188 while the three pawls 202 are in contact with each other. taken with the teeth 194 at the inner periphery of the ratchet wheel 188 and thus allow the rotation of the latter.

In other words, the three pawls 202 rotated by the motor 180 for the rotation of the ratchet wheel 188 do not generate a driving torque on the pawl 192 and therefore the connecting rod 186 connected to the handle 98. The major disadvantage of the order according to the patent US 4491709 is its mechanical complexity with two separate mechanisms for hand loading by the handle 98 or motor 180. Thus, on the one hand the use of a large number of mechanical drive elements connecting the actuating handle 98 to the pawl 192, such as connecting rods 182, 186 and their hinge axes 184, 187 makes complex assembly and operation of the control. On the other hand, the use of three different types of pawls 201, 192, 202 all arranged at peripheral proximity of the ratchet wheel 188 as a non-return ratchet makes it even more complex assembly and operation of the control.

The object of the invention is therefore to propose a new spring-type control unit equipped with a freewheel coupling device for discharging spring (s) for opening or closing contacts. high or medium voltage electrical equipment without application of a torque on a drive motor or crank, which overcomes all or part of the disadvantages of the controls according to the state of the art as mentioned above.

A particular aim is therefore to propose a new command of this type which is simple to make and which does not interfere with the closing or opening operation of the contacts of the electrical equipment during the unloading of the spring (s).

SUMMARY OF THE INVENTION

To do this, the object of the invention is a spring-type control for a high-voltage or medium-voltage switch comprising at least one spring, a first gear gear adapted to be rotated with drive power, a shaft adapted to rotate a movable contact of the switch during an operation of the switch, an arm secured to the shaft and connected to the spring (s), a freewheel coupling device coupling the first gear and the drive shaft in order to transmitting the driving power to the spring and thereby charging and uncoupling it to transmit the loaded spring torque to the moving contact but not the driving power.

• une deuxième roue dentée dont toute la périphérie externe est munie de dents en engrènement permanent avec la première roue dentée et dont toute une périphérie interne est munie de dents,
• un élément de libération agencé à la proximité périphérique de la deuxième roue dentée ;
• au moins un cliquet monté pivotant sur le bras et adapté pour être respectivement dans les positions :
• en engrènement avec les dents internes de la deuxième roue dentée pour charger le ressort tant qu'il n'a pas atteint son point mort haut de compression par rotation, dans un sens de rotation donné, de la deuxième roue dentée et du bras ainsi en engrènement avec celle-ci,
• en appui mutuel contre l'élément de libération dès que le ressort vient de passer son point mort haut de compression et ainsi être dégagé des dents internes par pivotement sur le bras dans le sens opposé au sens de rotation de la deuxième roue dentée tout en bloquant le bras,
• d'écartement du levier de libération par action sur celui-ci, afin de débloquer le bras et de l'entraîner en rotation, sous l'effort de déchargement du(des) ressort(s), dans le même sens de rotation donné tandis que la deuxième roue dentée reste immobile.

According to the invention, the freewheel coupling device comprises:

• a second toothed wheel whose entire outer periphery is provided with teeth in permanent engagement with the first toothed wheel and whose entire inner periphery is provided with teeth,
• a release member arranged at the peripheral proximity of the second gear;
• at least one pawl pivotally mounted on the arm and adapted to be respectively in the positions:
• in meshing with the internal teeth of the second toothed wheel to load the spring until it has reached its top dead center of compression by rotating, in a given direction of rotation, the second gear and the arm thus in meshing with it,
• in mutual support against the release element as soon as the spring has passed its top dead center of compression and thus be released from the internal teeth by pivoting on the arm in the direction opposite to the direction of rotation of the second gear while blocking the arm,
• spacing the release lever by acting on it, to unlock the arm and drive it in rotation, under the effort of unloading spring (s), in the same direction of rotation given that the second gear remains stationary.

In other words, the invention consists in judiciously integrating a freewheel coupling device consisting of a toothed wheel and a pawl meshing with it during the loading of the spring to its top dead point of compression, in abutment against a release element to disengage from the meshing engagement once the top dead center is reached, which allows the freewheeling operation of the arm and therefore of the drive shaft relative to the toothed wheel during actuation of the release element.

Such a device is particularly simple to implement and its freewheel operation does not lead to other element (s) than the arm, which avoids having a rotational inertia of parts to bear and therefore it does not affect the operation of closing or opening the switch.

The control according to the invention may comprise a plurality of pawls adapted to all be in the same positions simultaneously.

Advantageously, the release element is a pivotally mounted lever to allow it to be moved away from the pawl. The implementation of the release element is thus simple.

The invention also relates to a high or medium voltage electrical switchgear equipped with at least one switch, comprising a spring drive as described above.

The apparatus according to the invention may be gas-insulated, dead-tank type, or air-insulated, of the live-tank type. It can advantageously be a circuit breaker.

According to an alternative embodiment, the control comprises a single closing spring of the switch.

BRIEF DESCRIPTION OF THE DRAWINGS

• la figure 1 est une vue en perspective d'une partie d'une commande à ressort selon l'invention
• la figure 2 est une vue en perspective détaillée de la commande selon la figure 1,
• les figures 3A et 3B sont également des vues en perspective détaillée de la commande selon la figure 1 respectivement à l'état complètement chargé du ressort de fermeture de cette commande et au début d'une opération de déchargement du ressort de fermeture,
• la figure 4 est une vue en coupe transversale réalisée au niveau du dispositif d'accouplement à roue libre à cliquet selon l'invention.

Other advantageous and advantageous features of the invention will become more apparent on reading the detailed description given with reference to the Figures 1 to 3B among :

• the figure 1 is a perspective view of a portion of a spring drive according to the invention
• the figure 2 is a detailed perspective view of the control according to the figure 1 ,
• the Figures 3A and 3B are also detailed perspective views of the order according to the figure 1 respectively in the fully loaded state of the closing spring of this control and at the beginning of an unloading operation of the closing spring,
• the figure 4 is a cross-sectional view taken at the ratchet coupling device according to the invention.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

It is represented in perspective in figures 1 and 2 the spring energy storage control according to the invention, as it is implanted in a high-voltage circuit breaker.

The spring drive according to the invention comprises a mechanical coupling device freewheel between a crank or a motor not shown (e) and the drive shaft 1 of a movable contact of the circuit breaker, the freewheel operation performing a mechanical uncoupling between the crank or the motor and the drive shaft 1 when unloading the closing spring 11.

More exactly, the control firstly comprises a first gear wheel, called the output wheel 10, which is directly or indirectly driven by a crank or by a motor.

This output gear wheel 10 is in permanent engagement with a straight toothing performed on the entire circumferential outer periphery 5 of a second gear 2 mounted on a bearing not shown. In other words, this output gear wheel 10 is permanently coupled to the toothed wheel 2.

The second toothed wheel 2 comprises on an inner periphery of the teeth 4 of beveled shape.

Inside the inner periphery of the teeth of beveled shape is arranged an arm 3 secured to the shaft 1 for rotating the movable contact of the circuit breaker via the cam 12 shown in more detail in FIG. figure 3A . As illustrated, the arm 3 is fixed at the end of shaft 1 by screwing.

It goes without saying that one can consider any other method of fixation. Thus, the drive shaft 1 and the arm 3 are adapted to be rotated simultaneously.

As better visible in figure 1 on the arm 3 is fixed a pivot 6 which is itself connected to a helical compression spring 11 via a transmission system comprising a chain 13, a return pulley and rod 14 bearing against the end free of closing spring 11.

A pawl 7 is pivotally mounted about an axis 9 on the free end of the arm 3. When it is in its non-pivoted position (upwards in the figures), the pawl 7 meshes with the teeth 4 of the inner periphery of the second gear 2: there is therefore in this non-pivoted position a mechanical coupling between the latter and the arm 3 and therefore the drive shaft to which it is attached. When it is in its pivoted upward position, the pawl 7 is not meshing with the teeth 4: there is therefore in this pivoted position a mechanical disconnection between the toothed wheel 2 and the arm 3. The passage from its non-pivoted position to its pivoted upward position of the pawl 7 is made during the rotation of the arm 3 coupled to the toothed wheel 2 by peripheral abutment thereof against a lever 8, said trigger lever . This trigger lever 8 is a lever pivoting about an axis 80 and arranged near the toothed wheel 2.

It is specified here that, thanks to the relative arrangement between the different elements of the closing spring, the transmission system 12, 13, 14 and the arm 3 with its pivot as realized, the position pivoted upwards of the pawl 7 reached by peripheral abutment on the lever 8 ( figures 1 , 3A and 3B ) corresponds to the top dead center of the closing spring 11, that is to say its state of maximum compression.

The closing spring control 11 according to the invention finally comprises a non-return device, not shown, the function of which is to prevent either the output gearwheel 10 from rotating in the clockwise direction or the gearwheel 2 from rotating directly in the direction of rotation. the anti-clockwise direction in front view according to the figures. The function of this non-return device will be explained below in relation to the operation of the control. The arrangement of such a non-return device which can only be mechanical, can be easily achieved in the control by one skilled in the art without impairing the simplicity thereof.

The operation of the spring drive according to the invention will now be explained.

When it is desired to load the closing spring 11, the output gear wheel 10 is driven by a crank or a motor in the counterclockwise direction as seen from the front in the figures. The second gearwheel 2 is then rotated in the clockwise direction. The pawl 7 is then engaged with the teeth 4 of the inner periphery of the toothed wheel and thus the arm 3 is coupled in rotation with the toothed wheel 2 in this clockwise direction: it can be seen in FIG. figure 4 especially the mating between the actual coupling part 70 of the ratchet 7 complementary with the teeth 4 of beveled shape.

This engagement between pawl 7 and toothed wheel 2 takes place until the pawl 7 comes into peripheral abutment against the release lever 8. In this position, the closing spring 11 is thus almost completely loaded. The complete load of the closing spring 11 (top dead center reached) is reached when the upwardly pivoted position of the pawl 7 is reached by the support of the lever 8.

In this position pivoted upwards, the pawl 7 is no longer engaged, or in other words is released teeth 4: there is thus uncoupling between arm 3 and toothed wheel 2. This position of release of the pawl 7 thus allows the toothed wheel 2 continues to rotate without changing the position of the arm 3. Thus, the motor or the crank which drives the toothed wheel 2 through the output gear wheel 10 can therefore slow down gradually.

This avoids any damage to a mechanical element that would be due to a sudden stop of the engine or the crank. In other words, an operator can continue to turn the crank or the engine can continue to run without damage.

Moreover, thanks to the anti-return device, if an operator, who turns the output gearwheel 10 by means of the crank during the loading of the spring 11, looses it inadvertently then the arm 3 can not cause the toothed wheel 2 counter-clockwise. In other words, the operator is not likely to be injured by the crank because it can not be rotated by the gears 10, 2 blocked by the anti-return device.

When the circuit breaker is to be closed to cut a current, the trip lever 8 is rotated clockwise as best shown with the arrow shown in FIG. figure 3B . Once the release lever 8 is no longer in mutual contact with the pawl 7, the rotational locking of the arm 3 in a clockwise direction in front of the figures is removed.

The pawl 7 is also already no longer engaged with the teeth 4 of the inner periphery of the toothed wheel 2, the arm 3 and the switch drive shaft 1 to which it is attached then turn clockwise. under the pulling force of the chain 13 generated by the unloading force of the closing spring 11. In other words, they operate in freewheel with the toothed gear 2 mechanically uncoupled which therefore remains motionless in rotation. The drive shaft 1 therefore drives the moving contact of the circuit breaker via the cam 15.

The closing spring control 11 provided with the ratchet freewheel coupling device 7 is simple to implement and does not include a rotating component whose inertia would be detrimental to the closing operation of the circuit breaker during unloading. spring.

Other improvements or variants can be made without departing from the scope of the invention.

Thus, for example, although shown with a single ratchet 7, it is conceivable to arrange a plurality of pawls in engagement with the teeth of an inner periphery of the toothed wheel: in this configuration, it goes without saying that all the pawls are respectively engaged and disengaged from the teeth all simultaneously. In other words, the pivoting to reach their released position of the teeth is obtained simultaneously for all the pawls.

Furthermore, although shown with a transmission system (return pulley 12, chain 13), it is also possible to envisage a direct connection between one end of a spring and a pivot fixed on the arm, that is to say without using a chain with pulley.

Finally, although shown with a single spring for closing, the control according to the invention can also integrate several springs to compress.

Likewise, although shown in the form of a coil spring, one or more spiral springs can be used.

In fact, those skilled in the art will choose the type and the number of springs according to the torque necessary to cause the mobile contact (s) of the apparatus and the space that is to be dimensioned within the command.

Claims (8)

1. A spring type controller for a high-voltage or medium-voltage switch, the controller comprising: at least one spring (11); a first toothed wheel (10) adapted to be driven in rotation with a driving power; a shaft (1) adapted to drive a movable contact of the switch in rotation during an operation of the switch; an arm (3) secured to the shaft (1) and connected to the spring(s) (11); and a free-wheel coupling device coupling the first toothed wheel (10) with the drive shaft (1) in order to transmit the driving power to the spring (11) so as to load the spring, and uncoupling them in order to transmit the torque from the loaded spring to the movable contact but not to the driving power, the controller being characterized in that the free-wheel coupling device comprises:

   • a second toothed wheel (2) having its entire outer periphery (5) provided with teeth permanently meshing with the first toothed wheel (10) and having its entire inner periphery (4) provided with teeth;

   • a release element (8) arranged at the peripheral proximity of the second toothed wheel (2); and

   • at least one pawl (7, 70) pivotally mounted on the arm (3) and adapted to be in the following respective positions:

   • meshing with the inner teeth (4) of the second toothed wheel (2) to load the spring (11) until the spring reaches its compression top dead-center by rotation, in a given direction of rotation, of the second toothed wheel (2) and of the arm (3) thus meshing therewith;

   • bearing mutually against the release element (8) once the spring (11) reaches its compression top dead-center, thereby disengaging from the inner teeth (4) by pivoting on the arm in the direction opposite to the direction of rotation of the second toothed wheel, while blocking the arm (3); and

   • spaced apart from the release lever (8) by action thereon, in order to unblock the arm and allow it to be driven in rotation by the release force from the spring(s) (11) and in the same given direction of rotation, while the second toothed wheel (2) remains stationary.
2. A spring controller according to claim 1, characterized in that it has a plurality of pawls adapted so that all of them are in the same positions simultaneously.
3. A spring controller according to claim 1 or claim 2, characterized in that the release element is a lever (8) that is pivotally mounted to enable it to be moved apart from the pawl (7).
4. High- or medium-voltage electric switchgear provided with at least one switch and including a spring controller according to any one of claims 1 to 3.
5. Switchgear according to claim 4, characterized in that it is gas insulated, of the dead-tank type.
6. Switchgear according to claim 4, characterized in that it is air insulated, of the live-tank type.
7. Switchgear according to any one of claims 4 to 6, characterized in that the switch is a circuit breaker.
8. Switchgear according to any one of claims 4 to 7, characterized in that the controller has a single switch closure spring (11).

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