EP0448481B1 - Operating mechanism for a switch with three positions - Google Patents

Description

The invention relates to a control mechanism for an electric switch with a main shaft according to the preamble of claim 1.

A known control mechanism of the kind mentioned comprises two independent control devices, one for closing and opening the switch and the other for closing and opening the earthing. Each of these Tumbler-type devices has a spring and interlocking systems prohibit any false operation, in particular a closing of the earthing when the switch is closed. These devices are complicated and of uncertain reliability.

Also known, for example from documents EP-A-0 058 585 and EP-A-0 286 474, three-position control mechanisms actuated by a single spring associated with a toggle lever.

The invention aims to allow the realization of a simplified control mechanism with self-locking incorporated and abrupt operation.

The control mechanism according to the invention is described in claim 1.

The mechanism can control a three-pole switch of the type described in patent EP No. 270,389, in which the main shaft carries three contact bridges which cooperate with fixed contacts distributed over the periphery of the switch enclosure. The central position of the main shaft corresponds to the opening of the switch which can be closed by a rotation of this main shaft in a predetermined direction. Reverse rotation of the main shaft from the switch open position corresponds to grounding, in a manner well known to specialists. The closing and opening operation of the switch is controlled by an alternating rotation of the first control shaft, in particular by a control lever, while the closing and opening operation of the earthing device is controlled by the second shaft, in particular by means of a control lever. The rotation of the control shaft causes the spring to be cocked, which suddenly moves the main shaft as soon as it crosses neutral to carry out an abrupt maneuver. Each control shaft carries a plate with an eccentric pin and the spring is interposed between the two pins to selectively drive the plate as soon as it crosses neutral. The connection between the control shaft and the plate includes a light to allow a dead uncoupling stroke of the plate from the control shaft during the sudden movement phase generated by the relaxation of the spring. The main shaft carries a crank, the end of which is connected by two connecting rods to sectors mounted coaxially in rotation on the two control shafts. Each sector cooperates with the associated plate by a dead travel link allowing a positive drive of the sector by the plate during the rebound stroke of the spring. The connecting rod or lever constitutes with the associated sector a toggle joint the levers of which are substantially perpendicular in the open position of the switch, these levers coming into neutral position in the closed position ensuring positive locking of the main shaft. . The rotation of the sector in the closing direction is limited by a stop. The crank constitutes with each connecting rod a toggle joint, the assembly being arranged in such a way that in the closed position, for example of the switch, any action exerted on the earthing control shaft tends to accentuate the closing of the switch and vice versa. In the open position of the switch, each plate cooperates with a stop for limiting the rotation under the action of the spring. The plates carry control cams for locking levers arranged to lock the main shaft in the open position during the arming phase of the spring. At the end of the arming stroke of the spring, the corresponding cam actuates the locking lever so as to allow rotation of the main shaft in the direction imposed by the spring after crossing neutral. This locking device prevents any untimely rotation of the main shaft during the arming phases. This locking device also prevents kickback when the switch is opened. The mechanism includes an additional security constituted by an interlocking beam preventing the operation of the earthing when the switch is closed and vice versa. This interlocking flail cooperates with the control shafts for example by preventing the positioning of the operating lever. The mechanism can be motorized by coupling to the control shaft of the switch a motor with alternating direction of rotation, this motorization being favored by dead strokes allowing a gradual stop of the motor after the arming phase of the spring.

• la figure 1 est une vue schématique en perspective d'un mécanisme selon l'invention, le flasque avant étant représenté par son contour en traîts discontinus et l'interrupteur étant en position ouvert;
• la figure 2 est une vue éclatée du mécanisme selon la figure 1 montrant les positions respectives des différents composants;
• les figures 3, 4, 5, et 6 sont des vues analogues à celles de la figure 2 montrant le mécanisme respectivement en cours d'armement du ressort pour la fermeture de l'interrupteur; en position fermé de l'interrupteur; en cours d'armement du ressort pour la mise à la terre; la position de mise à la terre.

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

• Figure 1 is a schematic perspective view of a mechanism according to the invention, the front flange being shown by its contour in discontinuous lines and the switch being in the open position;
• Figure 2 is an exploded view of the mechanism according to Figure 1 showing the respective positions of the various components;
• Figures 3, 4, 5, and 6 are views similar to those of Figure 2 showing the mechanism respectively during arming of the spring for closing the switch; in the closed position of the switch; during arming of the spring for earthing; the grounding position.

In the figures, a main shaft 10 is rotatably mounted between two flanges 11, 12 secured by spacers 13. The main shaft 10 can be coupled or constitute the contact-carrying shaft of a three-position switch, for example of the type described. in European Patent No. 270,389. The main shaft 10 can occupy three distinct stable positions, in this case a central position C1 corresponding to the open position and on either side a position C2 for closing the switch and a position C3 for earthing . Positions C2 and C3 are symmetrical to C1 with an angular deviation of 60 ° but other values can be used. The main shaft 10 is mechanically connected on the one hand to a control device 14 for closing and opening the switch and on the other hand to a control device 15 for closing and opening the setting Earth. The control device 14 of the switch comprises a control shaft 16 on which are rotatably mounted a driver 17, a pair of plates 18 and a sector 19. Similarly the earthing control device 15 comprises a control shaft 20 on which are rotatably mounted a driver 21, a pair of plates 22 and a sector 23. An eccentric crank pin 24 is interposed and secured to the pair of plates 18 controlling the switch while a eccentric pin 25 is interposed and secured to the pair of plates 22 of the earthing control. A telescopic rod 26, articulated by its ends to the crank pins 24.25, carries a compression spring 27 biasing the crank pins 24.25 in the spread position. The driver 17 of the switch control device carries at its free end a coupler 28 of an operating lever (not shown) and at its end adjacent to the plate 18 two drive fingers 29.30 which frame with play an axis 31 carried by the pair of plates 18. The opposite end of the axis 31 is engaged in a circular lumen 62 formed in the sector 19. The sector 19 is mechanically connected to a crank 32, keyed onto the main shaft 10, by a lever 33 articulated to the crank 32 by a toggle 34 and articulated to the sector 19 by a toggle 35. It is easy to see that a rotation of the trainer 17 causes the displacement with play of the axis 31 and associated plates 18 as well as a rotation of the sector 19 transmitted by the articulated lever 33 to the crank 32 and to the main shaft 10.

In a manner similar to that described above, the driver 21 of the earthing device 15 carries at its free end a coupler 36 of an operating lever (not shown). The opposite end of the driver 21 carries two stops 37,38 framing with play an axis 39 carried by the pair of plates 22. The opposite end of the shaft 39 is interposed with play between two abutment surfaces 40,41 carried by the sector 23. The sector 23 is mechanically connected to the crank 32 by an articulated lever 42, one of the ends of which is connected to the toggle 34 of the crank 32 and the other end of which is articulated to the toggle 43 of the sector 23. The rotation of the driver 21 causes the displacement of the axis 39 with the plates 22 and that of the sector 23 whose rotation is transmitted by the lever 42 to the crank 32 and to the main shaft 10.

In the open position of the switch, shown in FIG. 2, the spring 27 biases the pair of plates 18 anticlockwise in support of a fixed stop 44. The line of action of the spring 27 is substantially perpendicular to the radius of the plate 18 passing through the crank pin 24.

The spring 27 similarly biases the pair of plates 22 of the earthing device in an anti-clockwise direction keeping the axis 39 in abutment against a fixed stop 45. The axis 31 at the bottom of light 62 prevents any rotation of the sector 19 in a clockwise direction and therefore any rotation of the crank 32 and the main shaft anticlockwise. The sector 23 in abutment against the axis 39 is prevented from turning in the clockwise direction and thereby hinders any rotation of the crank 32 and of the main shaft 10 in the clockwise direction . The finger 30 of the coach 17 cooperates with a fixed stop 46 while the rotation of the coach 21 is limited by a lug 47 cooperating with two fixed stops 48, 49.

The crank pin 24 of the crank 32 cooperates with a locking device constituted by a first lever 50 pivoting on a fixed axis 51, one end of which carries a roller 52 cooperating with the external surface of the plate 18 arranged in cam 53 and whose the opposite end carries an abutment surface 54 preventing rotation of the crank 32 anti-clockwise. The crank pin 24 cooperates with a second locking lever 55 pivoting on a fixed axis 56 and one of the ends of the second lever 55 carries a roller 57 engaged by the external surface of the plate 22 arranged in cam 58. The opposite end of the lever 55 carries an abutment surface 59 preventing, in the locked position, rotation in the clockwise direction of the crank 32.

The mechanism works as follows:

Closing of the switch (figure 1 to 4).

The mechanism being in the open position, shown in Figures 1 and 2, the operating lever is coupled to the driver 17 of the control shaft 16 of the switch. A rotation of the operating lever and the driver 17 clockwise causes the axis to move 31 and a clockwise rotation of the pair of plates 18 causing compression of the spring 27 during the arming phase of the latter shown in FIG. 3. During this arming phase the axis 31 moves in the light 62 without moving the sector 19, the crank 32 remaining in the central position while being locked by the abutment surfaces 54, 59 framing the crank pin 24 in the position C1. At the end of the arming phase of the spring 27, corresponding to the alignment of the shaft 16 and the crank pins 24.25, the spring 27 becomes motor and as soon as it crosses the neutral point causes the pair of plates 18 to rotate sharply independently of the trainer 17. This sudden rotation of the pair of plates 18 is transmitted by the axis 31, which has reached the bottom of the light 62 to the sector 19 whose pivoting in the clockwise direction is transmitted by the articulated lever 33 to the crank 32 and to the main shaft 10 which pivots anticlockwise towards the position C2 for closing the switch, shown in FIG. 4. This pivoting has been authorized by erasure of the abutment surface 54 due to the action of the cam 53 on the roller 52 at the end of the arming stroke of the spring 27 (FIG. 3). During the closing stroke, the levers articulated by the toggle joint 35, in this case the radius of the sector 19 passing through the toggle joint 35 and the articulated lever 33, pass from a position almost perpendicular to an alignment position shown in the figure. 4. The pivoting of the sector 19 is further limited by a stop 60. The torque transmitted to the crank 32 increases with the pivoting towards the closed position of the switch. During this closing stroke, the articulated lever 42 of the earthing device pivots slightly and transmits to the associated sector 23 a limited displacement due to the relative positions of the sector 23 and of the articulated lever 42. This limited displacement is compensated by the play between the abutment surfaces 40, 41 and the axis 39. The earthing device 15 is not otherwise affected by the closing operation of the switch.

Switch opening:

Starting from the closed position shown in FIG. 4, it suffices to actuate the driver 17 by the operating lever anticlockwise to drive the axis 31 by the finger 29 by causing a rotation. anticlockwise from the pair of plates 18 towards the arming position of the spring 27 shown in FIG. 3. During this arming phase the axis 31 slides in the light 62 without displacement of the sector 19. As soon as the neutral point is crossed, the spring 27 becomes active and rotates the plate 18 which drives the sector 19 by the axis 31 in an anticlockwise direction. This rotation is transmitted by the articulated lever 33 to the crank 32 and to the main shaft 10 which returns to the position illustrated in FIG. 2. At the end of the arming phase of the spring 27 the cam 53 releases the lever locking 50 which returns by any suitable means for example by a spring not shown in the locking position to trap the pin 34 returned to the open position. This locking device prevents any rebound when the switch is opened.

Grounding closure:

Starting from the open position shown in Figure 2, simply couple the operating lever to the driver 21 and turn the latter clockwise to move the axis 39 and the pair of plates 22 clockwise (Figure 5). During the arming phase of the spring 27 the axis 39 does not act on the sector 23, the abutment surface 41 being engaged only at the end of the arming phase. As soon as the neutral point is crossed, the spring 27 becomes a motor and suddenly drives the pair of plates 22 and by means of the axis 39 in abutment on the abutment surface 41 the sector 23 in a clockwise direction . This rotation is transmitted by the articulated lever 42 to the crank 32 and to the main shaft 10 which pivot together clockwise towards the earthing position. represented in FIG. 6. This pivoting is authorized by the withdrawal of the locking surface 59, which occurred at the end of the arming phase of the spring 27 by the action of the cam 58 on the roller 57. In the closed position of the earthing the toggle levers 43 are almost aligned and the rotation of the sector 23 is limited by a stop 61. This alignment prevents any reverse pivoting of the crank 32 and it is easy to see that in the manner described above the torque transmitted to the crank 32 increased during the closing movement of the earthing. The articulated lever 33 transmitted to sector 19 a limited movement authorized by light 62, the other components of the switch closing device remaining in their original position. In the earthing position shown in FIG. 6, an action on the sector 19 of the switch control device can only accentuate the closing of the earthing.

Grounding opening:

A rotation of the driver 21 anti-clockwise causes the axis 39 to be driven by the abutment surface 37 and an arming of the spring 27 by rotation anti-clockwise of the pair of plates 22. As soon as the neutral point is crossed, the spring 27 abruptly rotates the pair of plates 22 and the sector 23 anticlockwise returning the crank 32 to its open position. The locking device returns to the original frame position of the crankpin 34, avoiding any rebounding in the manner indicated above. The stops 46,48,49 limit the movements of the coaches 17,21 in order to avoid any false maneuvers.

The opening and closing control of the switch can be automated by coupling the driver 17 with an electric motor, for example capable of moving the driver 17 in rotation in one direction or the other. It is easy to see than the action of the motor stops at the end of the arming phase of the spring 27 during the closing stroke shown in FIG. 3 and that after interruption of the supply of the motor at this time, the latter can continue by inertia its rotation without catching the axis 31 suddenly moved by the spring 27. In the same way during an opening stroke the motor turns in the opposite direction and brings the spring 27 into the armed position before being stopped by interrupting the power supply while continuing its inertial movement without hampering the opening movement.

An additional interlocking is advantageously achieved by a flail preventing the simultaneous installation of operating levers on the shafts 16,20. By lengthening the light 62 or by moving the abutment surfaces 40, 41 it is possible to obtain a shock effect which can break the welding or inertia forces of the mechanism.

The invention is of course in no way limited to the particularly described embodiment, but it extends to any variant without departing from the scope of the invention as claimed, in particular that in which the abutment surfaces 40, 41 would be replaced by a light analogous to light 62. Conversely, the light could be replaced by abutment surfaces and the control shaft could be secured to the driver or to one of the other parts mounted for rotation on this shaft.

Claims (7)

1. An operating mechanism of an electrical switch with a main shaft (10) bearing or actuating contacts and capable of being selectively moved to three stable positions (C1, C2, C3), a central open position (C1) and on either side of this central position respectively a closed position of the switch (C2) and a closed position of the earthing device (C3), said main shaft (10) being connected by toggle levers (19, 33, 23, 42)

   - on the one hand to a first operating device (14) controlling closing and opening of the switch comprising a first operating shaft (16) controlling closing and opening of the switch by alternate rotation of this first shaft (16), said first operating shaft (16) bearing a first flange plate (18) having a first eccentric crankpin (24),

   - and on the other hand to a second operating device (15) controlling closing and opening of the earthing device comprising a second operating shaft (20) controlling closing and opening of the earthing device by alternate rotation of this second shaft (20), said second operating shaft (20) bearing a second flange plate (22) having a second eccentric crankpin (25),

   said first (14) and second (15) operating devices cooperating with a spring (27) imposing high-speed operations of said main shaft (10), characterized in that said spring (27) is inserted between the first (24) and second (25) crankgins in such a way as to transmit to said main shaft (10), via toggle levers (19, 33, 23, 42, a rotation torque from said central position (C1) to the closed positions (C2, C3) of the switch and earthing device to reach in the latter positions the deadpoint stably locking the main shaft (10).
2. The mechanism according to claim 1, characterized in that at least one of said operating shafts (16, 20) is connected to the associated flange plate (18, 22) by a dead travel coupling (29, 30, 31; 37, 38, 39) for positive transmission of the loading movement of the spring (27) to the flange plate (18, 22) and for high-speed relaxation of the spring with a corresponding rotation of the flange plate (18, 22) independent from the operating shaft (16, 20).
3. The mechanism according to claim 2, characterized in that said dead travel coupling (29, 30, 31; 37, 38, 39) comprises two stops arranged with clearance on each side of a spindle (31, 39).
4. The mechanism according to any one of the above claims, characterized in that each flange plate (18, 22) associated to an operating shaft (16, 20) has a stop (44, 45) defining the relaxed position of the spring (27) fitted between the crankpins (24, 25) of the two flange plates (18, 22) and that in said relaxed position the line of action of the spring (27) is appreciably perpendicular to the radius of the flange plate (18, 22) passing through the crankpin (24, 25).
5. The mechanism according to any one of the above claims, characterized in that each of said toggle levers (19, 33, 23, 42) comprises a first and a second lever, said first lever being constituted by a sector (19, 23) mounted in rotation on the operating shaft (16, 20) and that the connection between the flange plate (18, 22) and said associated sector (19, 23) presents a dead travel (31, 62; 39, 40, 41) for discoupling of the sector (19, 23) during the travel of the flange plate corresponding to loading of the spring (27) and for positive coupling during the relaxation travel of the spring (27) to drive the sector (19, 23) and contact-bearing main shaft (10).
6. The mechanism according to claim 5, characterized in that said main shaft (10) bears a crank handle (32) on the end (34) of which are articulated the second levers (33, 42) of said toggle levers (19, 33, 23, 42), that each sector (19, 23) cooperates with an end of travel stop (60, 61) defining the closed positions (C2, C3) respectively of the switch and earthing device and that in said closed positions the toggle constituted by the crank handle and corresponding second lever (33, 42) is in the deadpoint overshoot position to constitute a self-locking.
7. The mechanism according to any one of the above claims, characterized in that each flange plate (18, 22) bears an operating cam (53, 58) of a lock (54, 59) locking the main shaft (10) in both directions in the central open position (C1) and that rotation of the flange plate (18, 22) at the end of the loading phase causes the corresponding lock to be released to allow the main shaft (10) to rotate due to the action of the spring (27) in the corresponding direction.

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