FR2770680A1 - ROD CONTROL MECHANISM FOR A THREE-POSITION SWITCH - Google Patents

Abstract

An energy storage control mechanism for a three-position electric switch or circuit breaker comprises: - a first drive crank 7 cooperating with an opening lock 2, and wedged on an actuating shaft 24 with a second crank drive 6 articulated to one of the connecting rods 12, - an opening 33 made in the first drive crank 7 to move a crank pin 13 integral with a first control crank 11 for compression and relaxation a main spring 9, - and a transfer spring 1 secured to a crank pin 31 of a second control crank 4 connected to the first drive crank 7 by a mechanical link 25, the assembly being arranged to simultaneously arm the main spring 9 and the transfer spring 1, and to transfer the energy from the transfer spring 1 to the main spring 9 when the first drive crank 7 is released following the release of the verro u opening 2, first causing the compression and crossing of the dead center of the main spring 9, and then the relaxation of said main spring for the displacement of the second drive crank 6 to the open position of the light switch.

Description

CONNECTING ROD MECHANISM FOR A SWITCH WITH

THREE POSITIONS

  The invention relates to an energy storage control mechanism for an electrical switch or circuit breaker, having a rotary main shaft carrying or actuating the contacts, and capable of being brought selectively into three stable positions comprising a first central position d opening, a second position for closing the switch, and a third position for earthing, said main shaft being connected by transmission rods to a first control device DC1 for closing and opening the switch , and a second

  DC2 earthing control device.

  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 closing the earthing when the switch

is closed.

  Document FR-A-2660109 makes use of a single spring imposing abrupt maneuvers of the main shaft by means of toggle levers transmitting to the main shaft an increasing torque from said central position towards the closed closing positions. the switch and the earthing to come in these last positions to the neutral position of stable locking of the main shaft. A locking device prevents any untimely rotation of the main shaft during the arming phase, and prevents any rebound when opening. The mechanism comprises an additional security constituted by an interlocking preventing the operation of the earthing when the switch is closed, and vice versa. This interlocking cooperates with the control shafts for example by preventing the

  installation of the operating lever.

  The object of the invention is to improve the performance of a

  control of a switch or circuit breaker with three working positions.

  The control mechanism according to the invention is characterized in that the first control device comprises: - a first drive crank cooperating with an opening lock, and wedged on an actuation shaft with a second drive crank articulated to one of the connecting rods, - an opening in the first drive crank to ensure the displacement of a crank pin secured to a first control crank for the compression and relaxation of a main spring, - and a transfer spring subject to a crankpin of a second control crank connected to the first drive crank by a mechanical connection, the assembly being arranged to simultaneously arm the main spring and the transfer spring, and to transfer energy from the transfer spring to the main spring when the first drive crank is released following the unlocking of the opening lock, causing t first the compression and crossing of the neutral point of the main spring, and then the relaxation of said main spring for the displacement of the second drive crank towards the open position of

the switch.

  According to a characteristic of the invention, the opposite end of the main spring is attached to a third drive crank to which the other connecting rod is articulated

  transmission of the second control device.

  The second drive crank cooperates in the armed position with a closing bolt capable of maintaining the main spring and the transfer spring in the compressed state and preventing any movement of the third

  drive crank for earthing.

  According to another characteristic of the invention, the first drive crank comprises a snap rim and a support surface cooperating respectively

  with the opening latch, and with a stop in the armed position.

  Other advantages and characteristics will emerge more clearly from the description

  which follows of an embodiment of the invention, given by way of nonlimiting example and represented in the appended drawings in which: FIG. 1 is a schematic elevation view of the control mechanism according to the invention, said mechanism being shown in the open position; - Figures 2 to 4 are identical views of the mechanism of Figure 1 respectively in the armed position ready to close, in the closed position, and

closed position ready to open.

  With reference to the figures, the energy storage mechanism comprises a rotary main shaft 23 secured to an operating crank 22, and coupled or constituted by the contact-carrying shaft of a switch or circuit breaker which can be brought selectively into the one of three distinct stable positions. The main shaft 23 can thus occupy either a first central position for opening the switch (FIGS. 1 and 2), or a second position for closing the switch (FIGS. 3 to), or a third position for setting the earth diametrically opposite with respect to

the second position.

  The operating crank 22 carries an eccentric pin 21 on which two transmission connecting rods 12, 14 are articulated respectively coupled to a first control device DC1 for closing and opening the switch, and to a second

  DC2 control device for closing and opening the earthing.

  The first control device DC1 comprises an actuation shaft 24 on which are mounted a first drive crank 7 cooperating with an opening latch 2, and a second drive crank 6 coupled by a

  crank pin 10 to the connecting rod 12, and capable of cooperating with a closing lock 5.

  The second DC2 control device has a third crank

  drive 15 coupled by a crankpin 20 to the other connecting rod 14.

  A main spring 9 is inserted between the third drive crank 15, and a crank pin 13 secured to a first control crank 11 wedged on the actuation shaft 24. The crank pin 13 can move in a curvilinear opening 33 in the first drive crank 7. The main spring 9 is associated with a transfer spring 1, which is interposed between a fixed hooking member 19 and a crank pin 31 located on a second control crank 4 mounted at

pivot on an axis 3.

  A mechanical link 25 is arranged between the first drive crank 7 and the second control crank 4 so as to make the two springs 1, 9

dependent on each other.

  The operation of the energy storage mechanism is as follows: In the open position of FIG. 1, the first drive crank 7 is supported on the stop 8, and the two springs 1, 9 are in the relaxed state. The third drive crank 15 is in engagement against a stop 18, and the second drive crank 6 is in abutment against the closing latch 5. Arming phase of the mechanism To perform a closing sequence of the switch , it is necessary to carry out an arming of the mechanism beforehand following a rotational movement

  of the first drive crank 7 around the actuation shaft 24.

  The action of the crank 7 on the crank pin 13 causes the compression of the spring

  main 9, since the third drive crank 15 remains stationary.

  The rotation movement of the crank pin 13 in the clockwise direction allows the crossing of the top dead center formed by the alignment of the shaft 24, the

  crank pin 13 and the attachment point 32 of the main spring 9 to the third crank 16.

  The crank pin is in abutment against the left end of the lumen 33 formed in the crank 7 so as to apply a torque to the second crank

training 6.

  The rotation of the first drive crank 7 simultaneously causes, through the mechanical connection 25, the pivoting of the second control crank 4 anticlockwise, so as to compress the transfer spring 1. In the ready-to-close armed position illustrated in FIG. 2, the opening lock 2 positively locks the first drive crank 7

  resting against the stop 8, and maintains the two springs 9, 1 in the compressed state.

  The arming is finished and the energy retained in the transfer spring 1 will make it possible to make an opening operation after having previously operated a closing of the switch. The operating crank 22 and the transmission connecting rods 12, 14

  remain stationary during the arming operation.

  Switch closing phase In the CI2 operating mode corresponding to the hooking on opening and closing, the torque exerted by the crank pin 13 on the second drive crank 6 following the compression of the main spring 9 , is blocked by the opening latch 5 located in the locked position. Closing occurs as soon as the closing latch 5 is moved to the unlocked position following a manual unlocking action by a push button, or on the issue of an electrical command applied to a tripping coil. The couple rotates the second drive crank 6 via the crank pin 13, which moves along the lumen 33 from the first drive crank 7 to the

  abutted against the right end of the light 33.

  In the operating mode CI1, the absence of a closing latch 5 allows 1 5 to directly drive the second drive crank 6 in rotation from the

  main spring neutral shift 9.

  In both operating modes, the second drive crank 6 rotates the operating crank 22 anti-clockwise around the shaft 23 by means of the transmission rod 12. The shaft 23 arrives in the closed position, and the displacement of the connecting rod 14 and crank assembly

  has no effect on the main spring 9 which is in the relaxed state (FIG. 3).

  Transfer of energy and opening phase of the switch: From the closed position in FIG. 3, the opening sequence is operated by the release of the first drive crank 7 following the unlocking of the lock. opening 2 controlled by rotation anticlockwise. The transfer spring 1 initially compressed in the closed position of Figure 3, will relax, and causes the rotation of the second control crank 4 in a clockwise direction. The mechanical link 25 simultaneously drives the first drive crank 7 anti-clockwise,

  so as to compress the main spring 9.

  During the time of transfer of the energy from the spring 1 to the main spring 9, the driving torque exerted by the transfer spring 1, on the first drive crank 7, will remain greater than the driven torque, due to the reaction by the main spring 9 on the same crank 7, until the main dead center 9 is crossed (FIG. 4). The first drive crank 7 is then in abutment against the stop 8, and the crank pin 13 moves in the slot 33 of the crank 7 allowing the main spring 9 to relax, and by moving the second drive crank 6 counterclockwise. The operating crank 22 of the main shaft 23 is simultaneously actuated in a clockwise direction via the open position of the switch

(figure 1).

  Cable earthing phase This earthing phase occurs by actuating the third crank 15, the operating sequence of which is described in detail in the

  French patent application 90 03794.

Claims (4)

  1. Energy storage control mechanism for an electric switch or circuit breaker, having a rotary main shaft (23) carrying or actuating the contacts, and capable of being brought selectively into three stable positions comprising a first central opening position , a second position for closing the switch, and a third position for earthing, said main shaft (23) being connected by transmission rods (12, 14) to a first closing control device (DC1) and opening the switch, and to a second control device (DC2) for earthing, characterized in that the first control device (DC1) comprises: - a first cooperating drive crank (7) with an opening lock (2), and wedged on an actuation shaft (24) with a second drive crank (6) articulated to one of the connecting rods (12), - an opening (33) formed in the first crank the drive (7) for moving a crank pin (13) integral with a first control crank (11) for the compression and relaxation of a main spring (9), - and a transfer spring (1) secured to a crank pin (31) of a second control crank (4) connected to the first drive crank (7) by a mechanical connection (25), the assembly being arranged to simultaneously arm the main spring (9) and the transfer spring (1), and to transfer the energy from the transfer spring (1) to the main spring (9) when the first drive crank (7) is released following the release of the opening lock (2), causing first compression and crossing of the neutral point of the main spring (9), and then the relaxation of said main spring for the displacement of the second crank   drive (6) to the switch open position.   2. Control mechanism according to claim 1, characterized in that the opposite end of the main spring (9) is attached to a third drive crank (16) to which the other transmission connecting rod (14) of the second control device (DC2), via the crank (15) and the crankpin (17).   3. Control mechanism according to claim 2, characterized in that the second drive crank (6) cooperates in the armed position with a closing latch (5) capable of maintaining the main spring (9) and the spring transfer (1) in the compressed state, and prohibit any movement of the third   drive crank (15) for earthing.   4. Control mechanism according to claim 1, characterized in that the first drive crank (7) comprises a latching flange (35) and a bearing surface (36) cooperating respectively with the opening latch ( 2), and with a stop (8) in the armed position.