FR2640423A1 - CONTROL MECHANISM OF A MULTIPOLAR DIFFERENTIAL SWITCH WITH ROTATING SWITCHING BAR - Google Patents

Abstract

A differential switch comprises a switching bar 32 arranged as a rotary contact-carrier shaft 30, 26, a summing transformer 46 associated with a trip relay 54 with automatic reset, and a control mechanism 34 with handle 64 and latch 88. L ' end 74 of the connecting rod 70 located opposite the articulation axis 72 of the toggle cooperates during the establishment of the mechanical connection with a first bearing stop 76 of the hooking lever 78 and a second stop support 80 of the switching bar 32. The relay 54 transmits the triggering order to the latch 88 via a triggering lever 98 associated with an intermediate mechanical amplifier. This results in a three-stage mechanism for multiplying the forces between the relay 54 and the bar 32, which makes it possible to reduce the tripping energy.

Description

DIFFERENTIAL SWITCH CONTROL MECHANISM

  MULTIPOLAR WITH ROTATING SWITCHING BAR.

  The invention relates to a multi-pole differential switch with an insulating casing containing a control mechanism for a switching rod arranged in a rotating contact-carrying shaft movable between an open position and a closed position, and a summing transformer associated with an automatic resetting trigger relay when the bar comes into the open position, said mechanism comprising: - a pivoting lever coupled to a transmission link to constitute a toggle connected to the bar by a mechanical connection, - a lock cooperating with a latching lever to break the mechanical connection when the relay trips, - and a first return spring urging the bar towards the

open position.

  Such a differential switch is described in the patents

DE2504007 and 1563671.

  Bipolar or tetrapolar differential switches with high ratings have a high contact pressure. The automatic opening of these switches by tripping of the relay requires a fairly large tripping energy, which increases the size of the relay and the summing transformer, in particular in the case of a

  own current differential release.

  The object of the invention is to reduce the tripping energy of the differential switch relay, and to

  facilitate the mounting of the control mechanism.

  The differential switch according to the invention is characterized in that the end of the link located opposite the hinge pin of the toggle joint cooperates during the establishment of the mechanical connection with a first stop d support of the latching lever and a second abutment for supporting the switching bar, and that the relay transmits the triggering order to the latch by means of a triggering lever associated with an intermediate mechanical amplifier. The mechanical amplifier is formed by a half-moon articulated on an axis, and driven by the release lever by causing the displacement of the lock towards an unlocked position, authorizing the erasure of the first stop.

  support to release the transmission link.

  The presence of this mechanical amplifier in the mechanism forms three stages of reduction of the forces between the reais and the switching bar, which makes it possible to reduce

trigger energy.

  The latching lever is pivotally mounted on an axis, and comprises a holding spout cooperating with a latch retaining nose, the first support stop being arranged between the axis and the

holding spout.

  The trigger lever is pivotally mounted on an axis between a working position for energizing the relay and a non-triggering rest position, said lever comprising a first control branch capable of being actuated by the striker of the relay during 'a trigger, and a second control branch cooperating directly with a

half-moon paw.

  The control mechanism is carried by a support plate, which has an orifice serving as a bearing for the bar, and a notch for introducing the transmission rod to establish, at the end of assembly, the connection between the lever and the bar. This results in ease of mounting the control mechanism. Other advantages and features will emerge more

  clearly from the following description of a mode of

  embodiment of the invention, - given by way of non-limiting example, and shown in the accompanying drawings in which: - Figures 1 and 2 show the diagram and a view along line II-II of Figure 5 of the control mechanism , in the tripped position of the differential switch; - Figures 3 and 4 are views identical to Figures 1 and 2, in the closed position of the switch; - Figure 5 shows a plan view of the switch after removal of the cover; - Figures 6 and 7 show left and right side views of Figure 5; Figure 8 is a full sectional view of the differential switch. In the figures, a four-pole differential switch 10 is housed in an insulating boot 12 of parallelepiped shape, composed of a base 14 and a cover or cover 16 assembled to one another by snap-fastening. The base 14 contains the poles and has a fixing base 18 for mounting

  the switch 10 on a fixing rail (not shown).

  Each pole is connected to a pair of connection terminals 20,22 arranged on two opposite parallel faces (21,23) of the base (14) and comprises a fixed contact (24) cooperating inside an interruption chamber current with a movable contact piece 26. The fixed contact 24 is carried by a fixed conductive pad 28 connected directly to one of the terminals 20. The movable contact piece 26 is fixed to a pivoting contact arm 30, positioned in housing 31 of the bar of

  switching 32, which is arranged as a rotating shaft

  contacts. A contact pressure spring 33 is interposed in the housing 31 between the end of the contact arm 30 and the wall

of the bar 32.

  The switching bar 32 is common to all of the poles and

  extends above the interrupting chambers perpendicularly

  rement to the four contact arms 30. The axis 29 of rotation of the bar 32 extends in a horizontal direction parallel to the faces 21,23. One end of the rotary bar 32 is coupled to a control mechanism 34, and the other opposite end is provided with a cylindrical end piece 35 housed in a

bearing 36 secured to the base 14.

  Each contact arm 30 is connected by a braid 37 (FIG. 8) to a fixed conductor 39 connected to a fixed connection pad 38

  intermediate, projecting from the interrupting chamber.

  The different pole interrupting chambers are distributed at regular intervals along the horizontal bar 32, being isolated from each other by subdivision walls 40, 42, coming from molding with the base 14. The neutral pole is located on the side of the mechanism 34, and closes before the

three phase poles.

  The base 14 has another compartment 44 between the wall 42 and the terminals 22, for housing a summing transformer 46 with an O-ring core 48. The four primary windings 50 of the transformer 46 are shaped from the connecting conductors connecting the different 38 connection pads

corresponding terminals 22.

  The transformer 46 further comprises a secondary winding 52 electrically connected to the excitation coil of a trip relay 54 hooked to the

command 34.

  The mechanical components of the control mechanism 34 are carried by a fixed plate 56, which has an orifice

58 serving as a bearing for the bar 32.

  Two fixing screws 60, 62 fasten the control mechanism 34 to the base 14. The magnetic circuit of the trigger relay 54 is polarized by a permanent magnet, and requires a low

  tripping energy from the summing transformer 48.

  The control mechanism 34 has a manual closing and opening actuation by a handle 64, and an automatic triggering by means of the relay 54 upon detection of an insulation fault by the transformer 48. The handle 64 crosses a lumen 66 of the cover 16, and is mounted with limited pivoting on an axis 68 between two stable positions

  opening and closing of the switch contacts 10.

  A transmission link 70 comprising a metal stirrup in the shape of a U and of circular section is coupled to the internal base of the handle 64 to constitute the hinge pin 72 of a toggle joint. The articulation axis 72 is eccentric relative to the pivot axis 68 of the handle 64, and results from the introduction of one of the ends of the rod 70 in a

  orifice of the lever base 64.

  The opposite end 74 of the link 70 cooperates on the one hand with a first support stop 76 of a latching lever 78, and on the other hand with a second support stop 80 on the switching bar 32. The latching lever 78 is pivotally mounted on an axis 82 between an armed position and a disarmed position, and comprises at the opposite end of the axis S2, a holding spout 84 capable of cooperating in the armed position with a nose of

retainer 86 of a lock 88.

  The lock 88 is shaped as a double lever mounted with limited rotation on an axis 90 between a locked position and an unlocked position. One of the levers is constituted by the retaining nose 86, and the other latching lever 92 cooperates in the locked position with a step of a half-moon 94 articulated on an axis 96. The first support stop 76 is arranged between

the pin 82 and the holding spout 84.

  A trigger lever 98 is pivotally mounted on an axis between an excitation working position of the relay 54, and a non-triggering rest position, in which the mechanism 34 is respectively triggered or maintained in the armed state. A first control branch 102 of the trip lever 98 is capable of being actuated by the striker of the trip relay 54 (see arrow R in FIG. 3) when a leakage current to earth is detected. The release lever 98 has a second branch of

  control 104 cooperating directly with a tab 105 of the half

  moon 94, so as to unlock the catch lever 92

  of latch 88 when the relay 54 trips.

  A first return spring 106 biases the switching rod 32 towards the open position, when one of the stops 76.80 releases the lower end 74 of the rod 70. A second return spring 108 biases the trigger lever counterclockwise to the rest position, providing the reset energy

automatic relay 54.

  A third and a fourth return spring 110, 112 urge the half-moon 94 and the latch 88 in pivoting in a clockwise direction, towards their respective original positions. A fifth return spring 114 biases the latching lever 78 anticlockwise, after triggering, causing the latching to break

between beak 84 and nose 86.

  It is noted that the control mechanism 34 with differential triggering is provided with three stages of reduction of the mechanical forces, arranged between the triggering relay 54, and the switching bar 32. The presence of such a mechanical amplifier with three successive stages allows open a contact pressure differential switch

  high, from a low energy trip relay.

  The operation of the four-pole differential switch 10 is as follows:

MANUAL CLOSING

  From the open position (FIGS. 1 and 2), manual actuation of the lever 64 to the left, causes the drive rod 70 to be driven, with a simultaneous reaction of the lower end 74 on the two stops 76.80. The action on the first stop 76 generates the rotation of the latching lever 78 about the axis 82 so as to ensure the engagement of the retaining nose 84 against the retaining nose 86 of the latch 88. The latching lever 92 of lock 88

  hangs in the locked position on the half-moon step 94.

  The action on the second stop 80 causes the switching bar 32 to rotate about the axis 29 towards the closed position of the contacts 24, 26. The overtravel of the bar 32 makes it possible to ensure the contact pressure by means of the spring 33 associated with each contact arm 30. The movable contact of the pole

  neutral closes before the phase pole contacts.

  The switch 10 is then in the closed position of the contacts 24, 26, and in the armed state of the mechanism 34 (Figures 3 and 4).

MANUAL OPENING

  From the closed position (Figures 3 and 4), the rotation of the handle 64 to the right causes the displacement of the rod 70, the end 74 of which is permanently supported on the first stop 76 so as to maintain the mechanism 34 in the armed state. After a predetermined stroke of the handle 64, the end 74 of the rod 70 releases the second stop 80, allowing the automatic return of the switching bar 32 to the open position under the action of the first spring

reminder 106.

  AUTOMATIC DIFFERENTIAL TRIGGERING

  In the closed position of the switch 10 (Figures 3 and 4), the appearance of a leakage current to earth is detected by the summing transformer 48 which controls the tripping of the relay 54. The action of the striker (arrow R , Figure 3) on the first control branch 102 switches the trigger lever 98 around the axis 100 to the working position, in which the second control branch 104 abuts against the tab 105 by driving the half moon 94 rotating around the axis 96 counterclockwise. The step of the half-moon 94 escapes the latching lever 92 of the latch 88, which is driven by pivoting around the axis 90 against the force of the fourth return spring 112. This results in the unlocking of the attachment between the retaining nose 86 and the holding spout 84, followed by the rotation in a clockwise direction around the axis 82 of the attachment lever 78 towards the disarmed position. During this unlocking phase of the latching lever 78, the first support stop 76 disappears relative to the end 74 of the link 70. The support of the link 70 on the second support stop 80 is also released, allowing the bar 32 to rotate towards the open position under the action of the first

return spring 106.

  The pivoting of the release lever 98 towards the working position does not influence the state of the second return spring 108 which remains inactive. When the bar 32 comes to the open position, a cam of the latter acts on the second control branch 104 by means of a strand of the second return spring 108, causing the release lever 98 to return to the position rest, and rearming

  automatic relay 54 by the first control branch 102.

  A voluntary action of holding the handle 64 in the closed position immobilizes the link 70 as shown in Figures 3 and 4, but nevertheless allows the erasure of the first and second support stops 76.80, due to the rotation of the

  latching lever 78 after triggering of relay 54.

  The tripping force of the relay 54 passes through three reduction stages, defined by the tripping lever 98, the half-moon 94, the latch 88 and the lever

  attachment 78, before releasing the switching rod 32.

  The coupling of the transmission link 70 occurs at the end of mounting of the switch 10 after the first lever 64 and return spring sub-assembly (not shown), and the second sub-assembly formed by the bar 32, the mechanism 34, and the plate 56. The insertion of the rod 70 in the orifice of the lever, and on the two abutments 76.80 is carried out through a notch 120 of the plate 56. The establishment of the mechanism 34 takes place after that of the conductive copper part located in the lower part of the base, so as to reduce the lengths of the conductors

  connection, and to make welded connections accessible.

  The mechanism 34 can also be used in any other

  multipolar differential switch, in particular bipolar.

Claims (8)

  1. Multipolar differential switch (10) with insulating housing (12) enclosing a mechanism (34) for controlling a switching bar (32) arranged in a rotary shaft carrying contacts movable between an open position and a closed position , and a summing transformer (46) associated with an automatic resetting trigger relay (54) when the bar (32) comes to the open position, said mechanism comprising: - a pivoting lever (64) coupled to a connecting rod (70) transmission to constitute a toggle connected to the bar (32) by a mechanical connection, - a latch (88) cooperating with a latching lever (78) to break the mechanical connection when the relay is triggered (54 ), - and a first return spring (106) urging the bar (32) towards the open position, characterized in that the end (74) of the rod (70) situated opposite the axis of articulation (72) of the kneepad cooperates during the establishment of the mechanical connection with a first support stop (76) of the latching lever (78) and a second support stop (80) of the switching rod (32), and that the relay (54 ) transmits the trigger order to the latch (88) via a trigger lever (98) associated with a   intermediate mechanical amplifier.   2. Differential switch according to claim 1, characterized in that the mechanical amplifier is formed by a half-moon (94) articulated on an axis (96), and driven by the trigger lever (98) causing the displacement of the latch (88) to an unlocked position, allowing the first support stop (76) to be erased to release the transmission link (70).   3. Differential switch according to claim 2, characterized in that the latching lever (78) is pivotally mounted on an axis (82), and comprises a holding spout (84) cooperating with a retaining nose (86) of the lock (88), the first support stop (76) being arranged between the axis (82) and the spout hold (84).   4. Differential switch according to claim 3, characterized in that the latch 88 is shaped as a double lever mounted for rotation on an axis (90), and comprising a first lever fitted with the retaining nose (86), and a second lever d '' snap (92) cooperating in the locked position with a step of the half-moon (94).   5. Differential switch according to one of claims 2 to   , characterized in that the trigger lever (98) is pivotally mounted on an axis (100) between a working position of excitation of the relay (54) and a non-triggering rest position, said lever comprising a first branch control (102) capable of being actuated by the striker of the relay (54) during tripping, and a second control branch (104) cooperating directly with a tab (105) of the half moon (94).   6. Differential switch according to claim 5, characterized in that the trigger lever (98) is associated with a second return spring (106) arranged to remain inactive during the movement of said lever towards the working position, and cooperating with a switch bar cam (32) when the switch (10) opens, causing the relay (54) to automatically reset in the rest position   first control branch (102).   7. Differential switch according to one of claims 1 to   6, characterized in that the control mechanism is carried by a support plate (56), which has an orifice (58) serving as a bearing for the bar (32), and a notch (120) for introducing the transmission link (70) to establish at the end of assembly the connection between the lever (64) and the bar (32). 8. Differential switch according to claim 7, characterized in that the axis of rotation (29) of the bar of c .- :. ation (32) extends parallel to the respective axes (68,96,90,82, 100 ) of the lever (64), of the half-moon (94), of the latch (88) and of the levers (78.98) for hooking and triggering.