FR2812759A1 - CHAIN MANEUVER MECHANISM PROVIDED WITH A STARTING DEVICE FOR A HIGH-VOLTAGE ELECTRICAL SWITCHING APPARATUS - Google Patents

Abstract

A mechanism for operating a high-voltage electrical switchgear comprises an energy accumulator 10 with springs 26 and a transmission shaft 16. A traction chain 80 connects a movable end plate 30 of the accumulator 10, to a crank 72 of the shaft 16. A closing lock retains the transmission shaft 16 in an armed position very close to a top dead center of the mechanism. In the armed position, the force exerted by the energy accumulator 10 on the transmission shaft 16 is insufficient to drive the shaft 16. A starting device comprising a lever 106 returned by a starting spring 106 and provided with a cam 100 makes it possible to apply a calibrated torque to the transmission shaft 16 in the armed position. When the lock releases the shaft 16, the lever 106 drives the shaft 16 a few degrees, then the energy accumulator 10 takes over.

Description

MAN MECHANISM (CHAIN WORK PROVIDED WITH A DEVICE

  STARTING, FOR AN ELECTRICAL SWITCHING APPARATUS

HIGH TENSION

TECHNICAL FIELD OF THE INVENTION

  The invention relates to a mechanism for operating a high-voltage switchgear, in particular a circuit breaker, of the type comprising an elastic potential energy accumulator, a transmission shaft intended to drive at least one movable contact of the circuit breaker by means of a kinematic transmission, and a flexible traction link, of the traction chain or cable type, having two ends, one connected to the energy accumulator, and the other to the transmission, the flexible link passing through a

intermediate return pulley.

STATE OF THE ART

  Document EP 238 847 describes a mechanism of this type. The closing and resetting cycle of the mechanism requires a complete revolution of the drive shaft. The device combines two elastic energy accumulators each comprising a spring connected to the drive shaft via a chain. For each accumulator, the shaft passes through a top dead center position, in which the torque exerted by the accumulator chain on the shaft is zero and the spring is stretched to the maximum. A lock keeps the drive shaft in an armed position, close to these top dead centers. To reduce the forces exerted on the lock by the drive shaft in the armed position, the two top dead center positions are offset and the armed position is in between. In other words, when the shaft is in the armed position, the two chains are located on either side of the axis of rotation of the transmission shaft. Thus, in the armed position, the driving torque exerted by the first spring in the working direction is partially compensated by the torque exerted by the second spring in the opposite direction, which is lower. When the lock is cleared by a control device, the shaft begins to rotate under the action of the spring, the torque of which is preponderant. Then the second spring

  exceeds its neutral position, so that the two springs become motors.

  The start of the movement of the mechanism is therefore relatively slow, since at first, the first accumulator must work to raise the second accumulator to its neutral position. In addition, the race to be covered before the second energy accumulator becomes a motor is important. Indeed, for each chain, an angular sector called friction must be taken into account, corresponding to the positions close to top dead center, in which the force exerted by the chain generates a torque resistant by friction on the bearings of the shaft. transmission, which opposes the movement of the shaft. For the mechanism to work, it is necessary that in position

  armed, the chains are on either side of their angular friction sector.

  Before becoming drive, the second chain must therefore cross its entire angular friction sector. It is only after this rotation has taken place that the maximum torque on the shaft and therefore the maximum angular acceleration are reached. Finally, at the start of the movement, the first accumulator must provide additional work to slightly band the spring of the second accumulator, until the top dead center position of the second accumulator is reached. All these phenomena contribute to slowing down the start of the trigger movement of the mechanism. However, we realize that it is advantageous to have

  maximum torque as soon as possible in the travel of the mechanism.

STATEMENT OF THE INVENTION

  The invention aims to provide a mechanism of the above type, which allows very rapid actuation of high voltage electrical switchgear having a high electrical power, therefore a large mobile mass. More specifically, the invention aims to increase the acceleration of the mechanism at the start of closing, without increasing the stresses on the latch ensuring the maintenance of the mechanism in position

  armed, and without increasing the power of the mechanism's drive springs.

  According to the invention, this problem is solved by means of a mechanism for operating a high-voltage electrical switchgear comprising: * a chassis; * a mobile transmission shaft rotating around a geometric axis of rotation fixed relative to the chassis, the transmission shaft being provided with at least one transmission crank; a freewheel coupling connecting the transmission shaft to the chassis, allowing the rotation of the transmission shaft in a working direction and preventing rotation of the transmission shaft in a direction opposite to the working direction; has at least one accumulator of elastic potential energy, comprising a first end member movable between a charged position and a discharged position, the accumulator delivering motive kinetic energy when the first end member moves from its charged position to its discharged position, and accumulating a potential elastic energy when the first end member moves from its discharged position to its charged position; With at least one flexible traction link stretched between the energy accumulator and the crank, the flexible traction link having a first end integral with the first end member of the energy accumulator and a second end mounted on the crankshaft of the drive shaft, the drive shaft being able to assume a top dead center position and a bottom dead center position, the two neutral positions being positions in which the flexible link does not exert on the 'transmission shaft no torque with respect to the geometric axis of rotation of the transmission shaft, the bottom dead center position being reached when the first end member of the accumulator is in its discharged position; has a closing lock capable of locking the drive shaft in an armed position, corresponding to the charged position of the energy accumulator, the armed position being located between the top dead center position and the bottom dead center position , in the direction of work; * a switching shaft; * means for transmitting the movement of the transmission shaft to the switching shaft, capable of transmitting the movement of the transmission shaft to the switching shaft when the transmission shaft passes from a start position drive at a drive end position, in the working direction, and not to transmit the movement of the propeller shaft to the switching shaft when the propeller shaft moves from its end position d drive to its start training position, in the working direction, the start training position being located between the armed position and the bottom dead center position, in the working direction, the end position drive being located between the start of drive position and the top dead center position, in the working direction; a starting device capable of being applied to the transmission shaft in its

  armed position a motor torque, in the working direction.

  Because the drive shaft does not drive the switching shaft between the armed position and the start drive position, the torque required to switch from the armed position to the start drive position is low . The auxiliary starting device

  only drives the drive shaft to the start drive position.

  This makes it possible to choose an armed position very close to the top dead center position, in a so-called angular sector of friction where the energy accumulator is not yet driving because the force transmitted by the flexible link to the crank has a strong radial component which generates friction at the level of the shaft bearings, and a weak orthoradial motor component, which does not compensate for this friction. Since the canceled position is located after top dead center, the angle of rotation up to the start of drive position is small. As soon as the drive shaft moves away from the armed position, in the working direction, the mechanism leaves the angular friction sector of the accumulator. The accumulator becomes an engine even before the drive shaft has reached its start drive position. The distance to be traveled with the engine work of the starting device is therefore small and is traveled very quickly. From the start of the drive, the drive shaft exerts a significant torque on the switching shaft. Furthermore, the force exerted on the closing bolt by the drive shaft is perfectly calibrated, since it is essentially determined by the torque exerted by the starting device. This effort is low, on the one hand because the energy accumulator is not motor in the armed position, and on the other hand because the starting device does not have to provide a significant torque to drive the tree of

  transmission from its loaded position to its start training position.

  According to one embodiment, the starting device applies a motor torque to the drive shaft when the drive shaft is between a position for starting to take over, located between the bottom dead center and the top dead center, in the working direction, and an end of support position, located between the armed position and the bottom dead center position, in the working direction. The passage from top dead center is then facilitated

  by the starting device and is carried out with controlled energy.

  Preferably, the end of care position is located between the armed position and the start of training position, in the working direction. The starting device becomes useless as soon as the mechanism has reached a position sufficiently far from the top dead center position, in which the accumulator becomes engine. This position is

  reached before the start of the switching shaft drive.

  Preferably, the transmission shaft is able to transmit to the starting device a driving energy, when the transmission shaft passes from a winding position to the position of start of taking over, in the working direction, the position reassembly being located between the end of drive position and the start of support position, in the working direction. This allows the starting device to be reassembled, in a movement step where the mechanism does not act on the switching shaft. According to one embodiment, the end of drive position is located between the start of drive position and the bottom dead center position. The reassembly position is located between the bottom dead center position and the start of care position. The starting device is reassembled by a manual or motorized device also used

  for reassembling the accumulator.

  Advantageously, the armed position is close enough to the top dead center position so that when the transmission shaft is in the armed position, the energy accumulator exerts on the transmission shaft a motor torque zero or less than the torque

  exerted by the starting device on the drive shaft.

  According to a preferred embodiment, the starting device comprises an actuating member movable between a loaded position and an unloaded position and connected to a starting spring, the starting spring delivering a kinetic driving energy when the actuating member moves from its loaded position to its discharged position, and accumulating an elastic potential energy when the actuating member moves from its discharged position to its loaded position, said actuating member cooperating with a complementary member integral with the shaft of transmission. Advantageously, the actuating member is a lever pivoting relative to the chassis. According to one embodiment, the actuating member comprises a cam, the complementary member being a roller supported by the crank of the transmission shaft. The reverse arrangement is also possible.

BRIEF DESCRIPTION OF THE FIGURES

  Other advantages and characteristics will emerge more clearly from the description which follows.

  follow, of a particular embodiment of the invention, given by way of nonlimiting example, and represented in the appended drawings in which: FIG. 1 represents a perspective view of the mechanism of the invention in a point position dead low, some parts having been omitted for better viewing; - Figure 2 shows a view of the mechanism from another perspective, some parts having been omitted for better viewing; - Figure 3 shows a sectional view of the apparatus, showing a subset of energy accumulation; - Figure 4 shows a sectional view of the apparatus, showing a starting sub-assembly; - Figure 5 shows a sectional view of the apparatus, showing an arming sub-assembly; - Figure 6 shows a sectional view of the apparatus, showing part of a closing and opening control sub-assembly, in an armed, closed state; - Figure 7 shows a perspective view of part of the closing and opening control sub-assembly, with a handle in neutral position; - Figure 8 shows a sectional view of the apparatus, showing a sub-assembly

  for controlling an electrical reset circuit.

  DETAILED DESCRIPTION OF AN EMBODIMENT

  With reference to FIGS. 1 and 2, an operating mechanism for an electrical high-voltage cut-off device is mainly composed of a closing energy accumulator 10, an arming subset 12 and a switching shaft. 14, bound

  between them by means of a transmission shaft 16 and supported by a chassis 18.

  The switching shaft 14 is intended to be kinematically connected to one or more movable contact members of the switchgear, so as to drive them

  reversibly from an open position to a closed position.

  The chassis 18 comprises two parallel main plates 20, 22, fixed to each other by spacers 24. Certain elements of the mechanism are located between the plates 20, 22 so that in order to visualize them, it was necessary to represent dotted plate 20 on

  the view in FIG. 1 and to show the dashed plate 22 in the same way in FIG. 2.

  An intermediate plate 23 is held by spacers between the plates 20 and 22.

  The transmission shaft 16 and the switching shaft 14 are pivotally mounted on guide bearings (not shown) fixed to the plates 20, 22 of the chassis 18, so that their axes of rotation are parallel to each other. other and perpendicular to the planes of

plates 20, 22 and 23.

  The energy accumulator 10, shown in section in FIG. 3, comprises two pairs of coil storage springs 26, retained by a stiffening structure 28. This structure is composed of a first end plate 30 and a second end plate 32, connected to each other by means of a telescopic guide link. The telescopic link is formed by two parallel guides, each comprising a rod 34 secured to the first end plate 30, and sliding in a tube 36 secured to the second end 32. Each tube is provided with a bottom 38 pierced with an axial guide hole allowing the free translation of the corresponding rod 34. A stop 42 consisting of a washer of elastomeric material surmounted by a metal washer, rests on this bottom 38. The free end of each rod 34 is inserted into the corresponding tube 36 and provided with a nut 44 forming a likely shoulder to come into contact with the corresponding stop 42. The telescopic connection obtained allows a translational movement of the first end plate 30 relative to the second end plate 28, along a geometric axis of translation parallel to the rods 34. This movement is limited in the direction of separation by the meeting of the shoulder

  constituted by the nut 44, with the elastomer end stop 42.

  The coil springs 26 are supported by their ends on the end plates 30, 32 and are mounted coaxially outside each of the two parallel guides. The springs 26 are compression springs, that is to say springs which increase their potential energy when they are compressed and which provide work during their extension. In this case, the energy accumulator 10 is dimensioned in such a way that when the nuts 44 are in contact with the end of travel stops 42, the springs 26 are completely relaxed and just in contact with the two end plates 30 , 32. This state

  of the energy accumulator 10 will be said hereinafter discharged state.

  Two identical windows 50 of generally rectangular shape, visible more particularly in FIGS. 4 and 7, are formed in the plates of the frame 20, 22 and arranged opposite one another. Each rectangular window 50 defines two large lateral sides 52 and two small horizontal sides 54, 56, one lower (54), the other upper (56). Two spans 58 are arranged side by side along the short upper side of each window. The four bearing surfaces 58 together define a geometric support plane for the second end plate 32 of the energy accumulator 10, this plane being perpendicular to the

plates 20, 22 of the chassis.

  The end plates 30, 32 of the energy accumulator are provided with positioning ribs 60, cooperating with the windowsills, so as to guide the two end plates 30, 32, allowing their following translation a geometric axis perpendicular to the geometric support plane defined by the bearing surfaces 58. In other words, the rods 34 remain substantially perpendicular to the geometric plane

  support, whatever the movement of the energy accumulator 10 in the windows 50.

  Guidance is ensured with a play of a few millimeters. The long sides 52 of the two windows 50 are provided with two mounting grooves 62, allowing the lateral insertion of the

  sub-assembly formed by the energy accumulator 10 during assembly of the mechanism.

  The movement of the first end plate 30 is limited by four pads 64 of elastomeric material, which together define a geometric plane of contact with the plate 30. These pads 64 form end-of-travel stops for the first end plate 30. The studs 64 are screwed into nuts 66 welded to the flange of the short bottom sides 54 of the windows 50, and stopped by lock nuts 68. During assembly of the apparatus, the accumulator 10 is assembled as a sub-assembly. together outside the frame, in the form presented in FIG. 3. The distance between the upper and lower grooves 62 of the windows corresponds to the distance between the two end plates 30, 32 of the stiffening structure 28 of the accumulator 10 in its discharged state. In view of the insertion of this sub-assembly into the chassis, the studs 64 are screwed in fully, which has the effect of lowering the contact plane previously mentioned, below the level of the lower groove 62. It is then possible to insert the accumulator 10 laterally through the windows 50. Once the accumulator 10 is inserted, the studs 64 are partially unscrewed, so as to progressively raise the accumulator until the upper plate 32 either in contact with the bearing surfaces 58 and that the lower plate 30 is in contact with the studs 64, the accumulator 10 remaining in its discharged state. Finally, the locknuts 68 are positioned so as to block the studs 64 in position. Once the assembly is completed, the distance between the geometric support plane defined by the bearings 58 on the one hand, and the geometric contact plane defined by the studs 64 on the other hand, is substantially equal to the distance between the first plate 30 and the second plate 32 when the accumulator is

in its discharged state.

  The first end plate 30 projects through the windows 50 on either side of the space delimited by the plates 20, 22 of the frame 18. The two projecting parts of the

  plate 30 are each provided with a pair of oblong through holes.

  The transmission shaft 16 is provided with two identical parallel cranks 70, 72, visible in FIGS. 1 and 2. The cranks 70, 72 are located on either side of the portion of space delimited by the plates 20, 22 of the chassis. Each crank is provided with two flat cheeks perpendicular to the axis of rotation of the transmission shaft 16, forming between them a groove 74. The two flat cheeks support an eccentric axis 76,

  part of which is located in the throat.

  A flexible kinematic connection between the energy accumulator 10 and the transmission shaft 16 is established by means of two identical traction chains 80, which are located on either side of the space delimited by the two plates 20 , 22 of the chassis. The chains 80 have been shown in a simplified manner in the figures, but they preferably comprise articulated links. The assembly of the two chains 80 is symmetrical

  relative to a median geometric plane parallel to the plates 20, 22 of the chassis 18.

  Each traction chain 80 is stretched between one of the cranks 70 and the projecting part of the first plate 30 located on the same side of the plates 20, 22 of the chassis. One end of the chain 80 is provided with an eyelet 82 forming a bush which pivots on the eccentric axis 76 of the crank. In FIG. 2, the eyelet is shown in dotted lines, so as to allow the axis 76 to be viewed. The other end of the chain 80 is provided with a double eyelet 84,

  which is inserted into the pair of through oblong holes and stopped by a pin 86.

  The chain 80 passes through an intermediate pulley 90, mounted idly on an axis 92 supported by the chassis 18. A part 94 of the chain, stretched between the pulley and the first end plate, is parallel to the translation axis of the first plate 30, therefore parallel both to the geometric axis defined by the telescopic guide link of the stiffening structure 28 of the energy accumulator 10 and to the guide surfaces formed by the edges of the long sides 52 of the windows 50. Another part 96 of the chain is stretched

between the pulley and the axle 76.

  Each chain 80 works in a plane parallel to the plates 20, 22 of the chassis. There are two positions of the mechanism in which the geometric plane containing the geometric axis of rotation of the drive shaft 16 and the pivot axis 76 of the sleeve 82 becomes tangent to the periphery of the pulley 90 and to the part 96 chain. In one of these positions, visible in Figures 1 and 2, the sleeve 82 is located between the shaft 16

  and the pulley 90, which corresponds to a bottom dead center of the transmission shaft 16, that is to say

  say to a stable equilibrium position. In the other position, the transmission shaft 16 is located between the sleeve 82 and the pulley 90, which corresponds to a top dead center of the shaft 16, that is to say to a position of unstable balance. The length of the two chains 80 is such that when the drive shaft 16 is placed in its bottom dead center position - and stopped in this position -, and the accumulator 10 is in its discharged state, the first plate end 30 resting on the studs 64, the two chains 80 are only subjected to a very low tension, in fact the tension just necessary for their maintenance in the pulleys 90. As shown in FIG. 4, the central part of the one of the axes 76 further constitutes a roller 98 which cooperates with a cam 100 of a starting lever 102. The starting lever 102 is supported by a pivot 104 mounted on the chassis 18 and is returned by a starting spring 106, bandaged between a free end of lever 102 and a cleat mounted on the chassis. This sub-assembly constitutes a starting device. When the driveshaft 16 passes from the bottom dead center position to the top dead center position, it passes fleetingly through an intermediate winding position, in which the roller 98 meets the cam 100. When the shaft continues its rotation, the roller 98 arms the starting lever 102. The cam 100 has a top point 108. Shortly before arriving in the top dead center position, for example at 1 degree from this position, in a position called start of setting under load, the roller 98 passes the top 108 of the cam 100, so that the starting lever 102, returned by the starting spring 106, becomes engine relative to the roller 98. The starting lever 102 remains engine until the roller 98 loses contact with the cam 100, approximately 5 degrees after the top dead center position,

  in a so-called end of care position.

  The arming sub-assembly 12, a detail of which is shown in FIG. 5, comprises a ratchet wheel 110, integral with the transmission shaft 16, and which cooperates with five pawls, namely: two pawls 112, 113 mounted on a manual pumping lever 118, two pawls 114, 115 mounted on a stop support 120 secured to the chassis 18, and a pawl 116 mounted on a motorized pumping lever 122. Each pawl is returned to a coupling position with the ratchet wheel, by a torsion spring. The manual pump lever 118 and the motorized pump lever 122 are both pivotally mounted on the drive shaft 116. The pawls 112, 113, 114, 115, 116 and the ratchet wheel make freewheel couplings between the transmission shaft 16 and the manual pumping lever 118, between the transmission shaft 16 and the motorized pumping lever

  122 and between the transmission shaft 16 and the chassis 18.

  A free end of the manual pump lever 118 is connected to an input shaft 124 by means of a reduction lever 126 pivoting relative to the chassis around a pivot 128, and two transmission connecting rods 130, 132 connecting the transmission lever 126 on the one hand to a crank 134 of the input shaft 124 and on the other hand to the manual pumping lever 118. The end of the input shaft 124 includes a key 134 allowing the insertion of a removable crank 136 visible in FIG. 1. When an operator turns the crank 136 by one turn, the reduction lever 126 performs an oscillation which is transmitted with a reduction to the manual pumping lever 118, so that the manual pump lever 118 makes an angular oscillation - back and forth of an amplitude corresponding to about a tooth and a half of the ratchet wheel 110. However, the manual pump lever 118 is designed as a spare accessory. In normal use, it is in a rest position, pressing against an end of travel stop

138 of support 120.

  A free end of the motorized pumping lever 122 is provided with a roller 140 cooperating with a cam 142 keyed onto an output shaft 144 of a geared motor group 146, visible in FIG. 1. The geared motor group 146 comprises two electric motors 148 , 150 driving a gear train 152 connected to the output shaft 144. A return spring 154 tends to return the motorized pumping lever 116 anticlockwise in FIG. 5. When the output shaft 144 rotates one revolution, the motorized pumping lever 116 performs a two-way oscillation

  angular amplitude corresponding to approximately 3.8 teeth of the ratchet wheel 110.

  The two pawls 112, 113 supported by the manual pumping lever 118 form an angle between them corresponding to 4.5 teeth of the ratchet wheel 110. Likewise, the two pawls 114, 115 of the stop support 120 form between them an angle corresponding to 4.5 teeth of the ratchet wheel 110. In normal use, when the manual pumping lever 118 is in abutment against the stop 138, the pawl 114 of the stop support forms with the adjacent pawl 113 of the

  manual pump lever 118 an angle corresponding to 5.25 teeth of the ratchet wheel.

  Thus, when the ratchet wheel 110 starts to rotate in the opposite direction to that allowed by the pawls, it cannot cover an angle greater than that corresponding to 0.25 teeth.

  without being taken over and stopped by one of the pawls.

  The ratchet wheel 110 is provided with a toothless sector 158, which is at the height of the pawl 116 supported by the motorized pumping lever 122 when the drive shaft 16 is near the top dead center. When the toothless sector 158 is opposite the motorized pumping lever 122, the latter can perform a complete oscillation at

empty.

  Referring to Figure 6, the drive shaft 16 further supports and conventionally a drive cam 160 cooperating with a roller 162 mounted on a crank 164 fixed to the switching shaft 14. The cam has a part non-driving circular and a driving part. The switching shaft 14 is kinematically connected to at least one movable contact member 166 of the switchgear, via

  of a kinematic chain 168 that has been shown purely schematically.

  Naturally, the switching shaft can simultaneously drive several movable contacts, each corresponding to a pole of the apparatus. A classic configuration

  has three poles, corresponding to the three phases of a three-phase electrical network.

  The shaft 14 oscillates between an open position and a closed position forming an angle with one another. Moving from its open position to its closed position, the shaft 14 charges a spring with an elastic opening energy accumulator 170. A trigger 172 is pivotally mounted on the crank 164 of the switching shaft 14. A spring 174 tends to drive the trigger 172 projecting from the crank 164. The trigger 172 forms a spout which cooperates with an intermediate roller 176 carried by a reduction lever 178 which forms an intermediate lock. The reduction lever 178 pivots about an axis 180 and further comprises a second roller 182 cooperating with a rotary opening lock 184. The opening lock 184 is returned to the locking position by a spring (not shown), and controlled to an unlocking position by an opening control lock 186. This structure with three cascaded locks allows a reduction in the forces necessary for unlocking. The geometric axes of rotation of the three locks are mutually parallel and parallel to the geometric axes of rotation of the transmission and switching shafts 16 and 14. Each of the three locks is provided with a return spring (not shown), which tends to remember in the

  anti-clockwise in Figure 6 to a locked position.

  The opening control lock 186, the structure of which is visible in FIG. 7, comprises a material axis 210 having a semi-circular cut 212 cooperating with the opening lock 184, and two control cranks 214, 216. One end 218 of the axis 210 is mounted in a bearing supported by the intermediate plate 23 of the chassis, while a second bearing 222 is mounted on the plate 20. The control crank 216 is actuated by an electromechanical relay 190 for controlling electromagnet opening, fitted with an axial movement plunger 192. The control crank 214 is actuated by a pin 224 supported by a rotary control handle 226. The handle 226 comprises a flywheel 228 projecting in front of the plate 20, so as to be accessible by an operator, this flywheel being integral with '' a material rotation axis 230

  one end 232 of which is guided in rotation in the plate 20.

  The drive cam 160 is moreover provided with an eccentric axis, carrying a roller 194 intended to cooperate with a rotary closing lock 196. The closing locks 196 and closing control 200 are pivotally mounted, perpendicular to the plate. 20, therefore parallel to the axes of rotation of the transmission and switching shafts 16 and 14. They are both recalled by return springs which tend to recall them in the

  counterclockwise in Figure 6, toward their locked position.

  This structure with two cascaded locks allows a reduction in the forces necessary for unlocking. The closing control lock 200 has a structure close to that of the opening control lock 186, as shown in FIG. 7. It comprises a rotary material axis 240 having a half-moon cutout 242 cooperating with the closing lock 196, and two control cranks 244, 246. One end 248 of the axis 240 is mounted in a bearing supported by the intermediate plate 23, while a second bearing 250 is mounted on the plate 20. The three material axes 210 , 230, 240 are parallel, so that the geometric pivot axes of the closing control lock 200, the opening control lock 186 and the handle 226 are also parallel. The control crank 246 is actuated by an electromechanical relay 202 for closing the electromagnet, provided with a plunger 204 with axial movement. The control crank 244 is actuated by a pin 254

  supported by the rotary control handle 226.

  The steering wheel 228 of the lever 226 has a front face shown in FIG. 8, facing the operator. It is able to take three positions: a neutral position shown in FIG. 8, a manual opening control position, corresponding to a rotation of clockwise in FIG. 8, and a control position manual closing, corresponding to a rotation of 90 anticlockwise from the neutral position in FIG. 8. The lever 226 is returned to its neutral central position by a spring wire 260 working in bending. The ends of the spring wire 260 rest on two support axes 262, 264, and its middle part

  supports two ranges 266, 268 of the steering wheel, the range 268 being coaxial with the stud 254.

  When the lever 226 passes from its neutral position to its manual closing control position, the pin 254 comes into contact with the crank 244 of the closing control lock 196 and rotates the axis 240 and the half-moon 242 , releasing the closing latch 196. The bearing 266 presses on the spring wire 260, which flexes and tends to return the lever to its neutral position, so that the lever returns to the position as soon as the operator releases it. Similarly, when the lever 226 moves from its neutral position to its manual opening control position, the stud 224 rotates the crank 214 of the opening control lock 186, the axis 210 and the half moon 212 , releasing the opening lock 184. Simultaneously, the bearing 268 presses on the spring 260 which flexes

  and tends to return the lever 226 to its neutral position.

  When the roller 194 is locked by the latch 196, the drive shaft 16 is located approximately 1 degree beyond the top dead center position. This position of the mechanism will hereinafter be called the armed position, and corresponds to a compressed position of the spring accumulator 10, which will be called the charged position of the accumulator 10. It should be noted that the accumulator 10 is caused to be compressed very slightly beyond its

  loaded position, when the mechanism passes through top dead center.

  The transmission shaft 16 further comprises a reset control cam 204 visible in FIG. 7, on which the crank 70 has been deliberately omitted. The reset control cam 204 cooperates with a rocking lever 206 which drives an electrical contact 208. The electrical contact 208 makes it possible to open and close a supply circuit for the two electric motors 148, 150 of the geared motor. The operation of the mechanism will now be described, assuming that initially the drive shaft 16 is in the armed position and the switching shaft 14 in

open position.

  In the armed position, the transmission shaft 16 is retained in the immediate vicinity and slightly beyond the top dead center, by the attachment made by the closing latch 196. The springs 26 of the accumulator 10 are bandaged and exert on the two end plates 30, 32 a significant push tending to separate the plates 30, 32 from one another. The second end plate 32 is supported on the bearing surfaces 58, and the first end plate 30 is held in position by the two chains 80. However, the forces transmitted by the chains 80 to the cranks 70, 72 have a moment very low or zero with respect to the axis of rotation of the shaft 16, due to the position of the cranks 70, 72 and the friction of the mechanism. The starting lever 102 is in a driving position relative to the crank 72, and exerts on it a calibrated force corresponding to the setting of the starting spring 106. The reset control cam 204 does not act on the rocking lever 206, so that the electrical contact 208 is open and the motors 148,

are arrested.

  Starting from the armed position, a manual closing order on the lever 226, or electric on the closing control relay 202, pivots the closing control lock 200 so as to release the closing lock 196. The roller 194 drives then the lock 196 clockwise, which releases the drive shaft 16. The starting lever 102 then plays its driving role. It drives the roller 98 and with it the drive shaft 16, with a calibrated moment, over a few degrees to the end of support position, located at 5 from the top dead center position. Before even reaching this end of support position, the drive shaft 16 leaves the angular friction sector which corresponds to an angle of +/- 3 around the top dead center position,

  sort and the chains 80 start to transmit a driving torque to the cranks 70, 72.

  In this very first phase of closing, the switching shaft 14 remains stationary because the roller 162 still rolls on a part of the drive cam 160 which is circular and centered on the axis of rotation of the control shaft 16. This limits the work to be done

by starting spring 106.

  As soon as the angular position allowing the chains 80 to become driving is reached, the springs 26 of the accumulator 10 relax and drive the first end plate 30, the two chains 80 and the transmission shaft 16 in rotation. The second end plate 32 remains in abutment against the bearing surfaces 58. The drive cam 160 begins to drive the crank 164 when the roller 162 begins to roll on the non-circular driving part of the cam, which corresponds to a position early fugitive

  drive shaft drive, located 8 from the top dead center position.

  Driven by the cam 160, the crank 164 of the switching shaft 14 pivots from the open position to the closed position. The transmission shaft 16 therefore transmits in this

  phase the kinetic energy from the energy accumulator 10 to the switching shaft 14.

  When the switching shaft 14 reaches the closed position, the trigger spout 172 disappears in contact with the intermediate latch 178, then comes out under the thrust of the trigger spring 174. The thrust of the spring of the energy accumulator opening 170 tends to rotate the cam 164 clockwise, so that the trigger 172 bears against the intermediate latch 178, and biases the intermediate latch 178 clockwise. The intermediate lock bears against the opening lock 184 and urges it clockwise. The opening latch 184 in turn bears against the opening control latch 186 where it is blocked by the half-moon 212 in the locking position, thereby locking the switching shaft 14 in position closed. Before reaching the bottom dead center position, at 165 from the top dead center position, the cam 160 loses contact with the roller 162, which uncouples the switching shaft 14 from the drive shaft 16. In the subsequent reset phase, the drive cam 160 is no longer in contact with the roller 162, and the movement of the shaft

  transmission 16 is independent of that of the switching shaft 14.

  Shortly before the drive shaft 16 reaches its bottom dead center position, the rearming control cam 160 starts to drive the rocker lever 206 into a position for actuating the electrical contact 208. The latter closes a circuit of supply of the motors 148, 150, which start to drive the reduction trains 152. The motorized pumping lever 122 performs oscillations but the pawl 116 does not hook with the ratchet wheel 110 as long as the angular speed of the wheel 110 is greater than the angular speed of the pumping lever 122. Thus, the gearmotor can gradually reach its operating speed before starting to drive the shaft.

  transmission 16 in a later phase described later.

  When the drive shaft 16 reaches its bottom dead center position, the first end plate 30 reaches a transient position relative to the chassis 18, called the discharged position, corresponding to the discharged state of the accumulator 10. The nuts 44 of the rods 34 of the accumulator 10 reach the end of travel stops 42. In this transitory position, the second end plate 32 is still in contact with the bearing surfaces 58 while the first end plate 30 is just in contact studs 64. so that the

  limit switches 44 assume only the shock absorption.

  When the springs 26 are relaxed, the first plate 30 has acquired significant kinetic energy. As soon as the nuts 44 come into contact with the end of travel stops 42, the second plate 32 forms with the first a rigid assembly, and this assembly tends to come off its support on the bearing surfaces 58 and to move as a block on the thrust of the first plate 30. This energy is sufficient to cause an elongation of the chains 80 by elastic deformation. The first end plate 30 then sinks into the pads 64 which compress. Under the effect of these joint requests, the plate

  end 30 decelerates strongly until its speed is canceled.

  Due to the relatively large angular momentum of the drive shaft 16 and the moving masses which are integral therewith, the drive shaft 16 tends to continue its race beyond the bottom dead center and initiates a rearming movement by tending the chains 80 a little more. The studs 64 tend to want to regain their initial shape and to push back the end plate 30, thus restoring to it a part of the energy which they have

  stored. Simultaneously, the chains 80 tend to regain their initial size.

  Its effects add up to immediately propel the end plate 30 in the direction of rearming. In practice, it is found that the contact between the plate 30 and the studs 64 gives rise only to a rebound. It should also be emphasized that this phase is very rapid and that the deformations described are of very small amplitude. As an indication, the amplitude of the overtravel of the first end plate 30, which corresponds to the insertion of the studs 64 and approximately to the detachment of the second plate

  32 is of the order of ten millimeters.

  Under the effect of the kinetic energy of the drive shaft 16 and the moving masses which are integral with it, the drive shaft 16 performs almost a third of the rearming stroke by gradually decelerating until that the ratchet wheel 110 causes the coupling of the transmission shaft to the geared motor. In this phase, the transmission shaft 16 plays the role of a flywheel. The mechanism therefore makes it possible to recover in this phase a significant part of the energy available in the mechanism when passing through the bottom dead center, thereby saving considerable time in the phase.

  subsequent reset of the accumulator 10, which will now be described.

  Under the effect of the springs 26 of the accumulator 10, the speed of rotation of the transmission shaft 16 is canceled, and the shaft 16 tends to start again in the opposite direction. Immediately, one of the four stationary pawls 112, 113, 114, 115 hooks the ratchet wheel 110, unless it is directly supported by the pawl 116 of the motorized pump lever 122, according to its own oscillation. The staggered arrangement of the four pawls 112, 113, 114, 115 makes it possible in any case to guarantee that the shaft 16 will be hung before having traversed more than a quarter of the angular sector of a tooth of the ratchet wheel in the opposite direction to the direction of travel. This therefore makes it possible to limit the impact of the pawl taking charge of the ratchet wheel 110. The motorized pumping lever 122 then takes charge of the ratchet wheel 110 and makes it travel through an angular sector corresponding to 3.5 teeth each. its half-motor oscillations. During each non-driving half-oscillation, when the cam 142 releases the motorized pumping lever 122 and the spring 154 returns the lever 122 to its end-of-travel position anticlockwise in FIG. 5, the ratchet wheel 110 rests on one or other of the four pawls 112, 113, 114, 115. The transmission shaft 16 ensures the transmission to the accumulator 10 of the mechanical energy produced by the motors 148, 150. The compression of the springs 26 of the accumulator 10 continues until the transmission shaft 16 reaches its top dead center. When the drive shaft 16 continues its race towards top dead center, the roller 98 of the crank 72 meets the starting lever 102 and drives the latter to an arming position by tensioning the starting spring 106. Shortly before as the transmission shaft 16 reaches its top dead center, the roller 98 passes the top 108 of the cam 100 of the starting lever 102, so that the starting lever 102 becomes engine. Almost simultaneously, the pawl 116 of the motorized pumping lever 122 is found opposite the angular sector without teeth 158 of the ratchet wheel 110, while the reset control cam 204 releases the contact 208 which opens the circuit. supply of motors 148, 150. Even if the stopping of electric motors is not instantaneous, the absence of teeth

  ensures decoupling between the motorized pumping lever 122 and the drive shaft 16.

  The transmission shaft 16 passes the top dead center under the bias of the starting lever 102, until the roller 194 of the drive cam 160 comes into contact with the closing latch 196. The latch is biased in clockwise, but blocked in the position of FIG. 6 by the half-moon 242 of the closing control lock 200. The transmission shaft 16 then comes to a standstill in the armed position. The subset of

  control is then in the armed, closed state, represented in FIG. 6.

  As for the switching shaft 14, its subsequent movement, from the closed position, is dictated by the opening spring 170 and by the opening latch 184. The manual opening order given by rotation of the lever 226, or electric by the electromechanical relay 190, is transmitted to the opening control lock 186, to the opening lock 184 and to the intermediate lock formed by the reduction lever 178, the latter disappearing and releasing the trigger 172. The switching shaft 14 then passes from the closed position to the open position under the action of the spring of the opening energy accumulator 170 which discharges, without the roller 162 meeting the drive cam 160 Arrived in the open position, the switching shaft 14 is stopped by end-of-travel stops (not shown), and the roller 162 comes into contact with the cam, if the latter has

completed its rearmament.

  Naturally, various modifications are possible.

  The electrical equipment concerned can be of any type, in particular a high voltage circuit breaker or a high voltage switch. The target area of tension includes as well

  medium voltage than very high voltage.

  The gearmotor can be driven by only one electric motor.

  The mechanism may include only one traction chain. The chain or chains can be replaced by any type of flexible link allowing a tensile stress, for example a belt or a cable. Naturally, it will be advantageous to choose a flexible link having a certain elasticity. In practice, the elasticity of conventional articulated traction chains is sufficient to allow an extension of the chain when passing through the

bottom dead center.

  The armed position can be located slightly before or slightly after the top dead center position, in the angular friction sector where the traction chains do not

  cannot have a driving action on the drive shaft.

  The energy storage springs can be tension springs rather than

  compression springs, if the overall dimensions allow it.

  In the discharged state of the accumulator, the springs 26 may still be slightly compressed, which limits their movement when they are subjected to the shocks of passage through the bottom dead center. The discharged state is always the state in which the springs 26 can no longer supply energy to the plate 30, and corresponds to the position o the nuts 44

meet the stops 42.

  The intermittent transmission members that constitute the pump levers 118 and 122 can be replaced by continuous transmission means. Freewheel couplings can be made by other means than by a ratchet wheel mechanism 110 and pawls 112, 113, 114, 115, 116, for example with balls or rollers

  coupling intermediaries between two cylindrical surfaces.

  The starting sub-assembly can be of any type making it possible to apply a force to the shaft on part of the stroke thereof, close to the armed position. It may for example be a device with a mobile drawer in translation. This sub-assembly does not necessarily act on the crank 72, since any element integral with the shaft may also be suitable. It is possible to provide that the reassembly of the starting spring is not carried out via the transmission shaft, but for example directly by the gear motor. The number of intermediate locks between the closing lock and the corresponding relay on the one hand, and the opening lock and the corresponding relay on the other hand, is chosen by

  function of the reduction in effort required.

Claims (8)

  1- Mechanism for operating a high voltage electrical switchgear comprising: a chassis (18); To a drive shaft (16) rotating in rotation about a geometric axis of rotation fixed relative to the chassis (18), the drive shaft (16) being provided with at least one drive crank (70, 72 ); ò a freewheel coupling (110, 114, 115) connecting the transmission shaft (16) to the chassis (18), allowing the rotation of the transmission shaft (16) in a working direction and preventing rotation of the transmission shaft (16) in a direction opposite to the working direction; ò at least one accumulator of elastic potential energy (10), comprising a first end member (30) movable between a charged position and a discharged position, the accumulator (10) delivering motive kinetic energy when the first member d the end (30) moves from its loaded position to its discharged position, and accumulating a potential elastic energy when the first end member (30) moves from its discharged position to its charged position; 20. at least one flexible traction link (80) stretched between the energy accumulator (10) and the crank (70, 72), the flexible traction link (80) having a first end (84) integral with the first end member (30) of the energy accumulator (10) and a second end (82) mounted on the crank (70, 72) of the drive shaft (16), the drive shaft (16 ) being able to take a top dead center position and a bottom dead center position, the two neutral positions being positions in which the flexible link (80) exerts no torque on the drive shaft (16) relative to the geometric axis of rotation of the drive shaft (16), the bottom dead center position being reached when the first end member (30) of the accumulator is in its discharged position; * a closing lock (196) capable of locking the drive shaft (16) in an armed position, corresponding to the charged position of the energy accumulator (10), the armed position being located between the point position top dead and bottom dead center, in the working direction; characterized in that the mechanism further comprises: * a switching shaft (14); ò means (160, 162) for transmitting the movement of the transmission shaft (16) to the switching shaft (14), capable of transmitting the movement of the transmission shaft (16) to the transmission shaft switching (14) when the drive shaft (16) passes from a drive start position to a drive end position, in the working direction, and not to transmit the movement of the drive shaft transmission (16) to the switching shaft (14) when the transmission shaft (16) passes from its end of drive position to its start of drive position, in the working direction, the start position drive being located between the armed position and the bottom dead center position, in the working direction, the end of drive position being located between the start training position and the top dead center position, in the sense of work; * a starting device (102, 106) suitable for applying to the transmission shaft   (16) in its armed position a driving torque, in the working direction.   2 - operating mechanism according to claim 1, characterized in that the starting device (102, 106) applies a driving torque to the drive shaft (16) when the drive shaft (16) is between a position start of support, located between the bottom dead center and the top dead center, in the working direction, and a position of end of support, located between the armed position and the bottom dead center position, in the sense of work.   3 - operating mechanism according to claim 2, characterized in that the end of support position is located between the armed position and the start position   in the direction of work.   4- operating mechanism according to any one of the preceding claims,   characterized in that the drive shaft (16) is capable of transmitting driving energy to the starting device (102, 106) when the drive shaft (16) goes from a winding position to the starting position in the direction of work, the reassembly position being located between the end of training position and the position of   start of care, in the direction of work.   - Operating mechanism according to claim 4, characterized in that the winding position is located between the bottom dead center position and the start of setting position in charge.   6- Operating mechanism according to any one of the preceding claims,   characterized in that the end of drive position is located between the start position   drive and the bottom neutral position.   7- operating mechanism according to any one of the preceding claims,   characterized in that the armed position is close enough to the top dead center position so that when the drive shaft (16) is in the armed position, the energy accumulator (10) exerts on the drive shaft (16) an engine torque zero or less than the torque exerted by the starting device (102, 106) on the drive shaft transmission (16).   8- operating mechanism according to any one of the preceding claims,   characterized in that the starting device comprises an actuating member (102) movable between a loaded position and an unloaded position and connected to a starting spring (106), the starting spring (106) delivering motive kinetic energy when the actuating member (102) moves from its charged position to its discharged position, and accumulating a potential elastic energy when the actuating member (102) moves from its discharged position to its charged position, said member d actuation (102) cooperating with a complementary member (98) integral with the shaft transmission (16).   9- Operating mechanism according to claim 8, characterized in that the member   actuator (106) is a lever pivoting relative to the chassis.   - Operating mechanism according to claim 8 or claim 9, characterized in that the actuating member (106) comprises a cam (100), the complementary member (98) being a roller supported by the crank (72) from the tree of transmission (16).