FR2709370A1 - Electromagnetic relay with bistable contact. - Google Patents

Abstract

An electromagnetic relay comprises an electromagnet (14) with a swiveling paddle (38), a mechanism (16) with a rocker (44) intended to drive a tilting contact (20) bistable, and an elastic device for returning the paddle (38) towards a separated position when the coil of the electromagnet (14) is not energized. A connecting rod is articulated on the pallet (38) and the balance (44), and the return device comprises a pair of compression springs, one of which acts later than the other. A contact position indicator (72) is integrated inside a manually controlled test button (70), and comprises an optical prism (78) cooperating with a feeler (80) integral with the pallet (38).

Description

ELECTROMAGNETIC RELAY WITH BISTABLE CONTACT

  The invention relates to an electromagnetic relay housed in an insulating box containing: - an electromagnet with a pivoting ferromagnetic pallet, - a pendulum control mechanism mounted to tilt on an axis between two extreme angular positions, - a control member integral with the pallet and cooperating with the balance to move it from one position to the other at each cycle of operation of the pallet, an electric power circuit having a bistable tilting contact driven by the balance, and cooperating with at least one fixed contact, and an elastic device for returning the pallet to the separated position in the state

of the electromagnet.

  An apparatus of this type is already described in document FR-A-2,676,590 by the applicant. A change of state of the contacts occurs at each current pulse applied to the electromagnet coil thanks to the intervention of a control member cooperating with the balance. This control member is formed by a simple pusher attached to the pallet. Such an assembly does not constitute a direct and permanent mechanical connection with the balance, and the device operates

only in remote control mode.

  The object of the invention is to provide a device operated by a bistable tilting contact, and easily configurable as an electromagnetic relay from

  of a standard structure of a remote control switch.

  According to the invention, the control member comprises a connecting rod articulated on the pallet and the balance to form a permanent direct connection, the point of articulation of the rod on the balance being offset relative to the axis of

tilting.

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  The simple replacement of the pusher by the link articulated to the pallet and the balance makes it possible to transform the remote control switch into a relay, in particular a contactor. According to a characteristic of the invention, the elastic return device comprises a pair of compression springs acting on the underside of the pallet, and extending parallel to each other and to the link in a substantially perpendicular direction with the pallet, the two springs having characteristics

  of different length and stiffness, one of the springs acting before the other.

  According to another characteristic of the invention, a contact position indicator is integrated inside the manually controlled test button. The indicator is composed of an optical prism cooperating with a probe integral with the pallet, the probe having two signaling pins arranged alternately opposite the

  inclined face of the prism according to the position drawn or moved away from the pallet.

  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 shown in the appended drawings, in which FIG. 1 is an elevation view of the electromagnetic relay according to the invention,

  shown in the OFF position when the electromagnet is not supplied.

  Figure 2 is an identical view to Figure 1, the relay being equipped with a device

  additional with test button and contact position indicator.

  Figure 3 is a sectional view along line 3-3 of Figure 2.

  Figure 4 shows a partial view of Figure 2, showing the indicator in

  ON position of the relay following energization of the electromagnet.

  Figure 5 is a sectional view along line 5-5 of Figure 4.

  Figure 6 shows a partial view of Figure 2, after pressing the button

test.

  Figure 7 is a sectional view along line 7-7 of Figure 6.

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  Referring to Figure 1, the change-over relay 10 is housed in a housing 12 of molded insulating material containing an electromagnet 14, a control mechanism 16, and an electric power circuit 18 having a movable contact 20 tilting cooperating with two fixed contacts 22, 24. The fixed contact 22 is connected to a first terminal 26, and the other fixed contact 24 of the change-over relay 10 is connected to a second terminal 28, the two terminals 26, 28 being located on the same side of the

housing 12.

  The movable contact 20 is equipped with a contact arm 30 pivotally mounted on a knife joint 32, arranged at the end of a rigid conductor 34, the other end of which is connected to a third terminal 36. The arm contact 30 is associated with a spring 38 in the form of an elastic blade making the movable contact 20

  bistable. The third terminal 36 is located opposite the other two terminals 26, 28.

  The electromagnet 14 comprises a ferromagnetic pallet 38 pivotally mounted on the left part of the cylinder head 40, and a biasing spring 42 cooperates with the pallet 38 in the vicinity of the articulation zone 43 to ensure minimum clearance

during the pivoting movement.

  The control mechanism 16 comprises a balance 44 pivotally mounted on a fixed axis 46 between two extreme angular positions, and a connecting rod 48 for articulation at one of its ends on the pallet 38, and at its other end on the balance 44. The articulation point 50 of the link 48 on the pendulum 44 is

  offset from the tilting axis 46.

  The pendulum 44 has a U-shape having a central recess 52 in which the end of the contact arm 30 is engaged. The pallet 38 moves the pendulum 44 from one position to the other at each operating cycle of the pallet 38 according to

  the electromagnet 14 goes from the excitation state to the rest state, or vice versa.

  In the idle state of the electromagnet 14 corresponding to the absence of excitation of its coil, the pallet 38 is kept apart from the pole surface 54 of the cylinder head by means of an elastic return device 56 arranged between the housing 12 and a portion of the palette. The return device 56 comprises a pair of compression springs 58, 60 bearing on protrusions 62 of the housing 12, and acting directly on the underside of the pallet 38 in the direction of separation. The movable contact 20 is in abutment against the upper fixed contact 24 in the

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  position shown in Figure 1. The two springs 58, 60 extend parallel

  to each other in a direction perpendicular to the pallet 38.

  When the electromagnet 14 is energized, the pallet 38 is attracted against the pole surface 54, and the link 48 causes the rocker 44 to tilt so as to drive the movable contact 20 towards the lower fixed contact 22. The modulation of the return force by the two springs 58, 60 allows optimum accumulation of the excess energy supplied by the electromagnet 14 during the attraction of the

pallet 38.

  After the excitation of the electromagnet 14 is stopped, the magnetic attraction forces in the air gap between the pole surface 54 and the pallet 38 disappear, and the mechanical energy accumulated in the springs 58, 60 is restored in the manner next The spring 58 on the left, located between the articulation zone 43 of the pallet 38 and the other spring 60 on the right, is used to detach the contacts 20, 22 when the contact arm 30 pivots counter-clockwise. 'a watch. The shorter spring 58 has a higher hardness than the longer spring 60. The trigger of the first spring 58 on the left is used to break the micro-welds, while the other spring 60 on the right ensures the complete spacing of the pallet 38, and the tilting of the movable contact 20 towards the other stable state in contact support

fixed 24 upper.

  In each stable state of the movable contact 20, it is noted that there is a predetermined clearance between the contact arm 30 and the spout 64, 66 of corresponding drive of the balance wheel 44. The presence of this clearance generates a shock effect during the change of state, and promotes breakage of the welds in each series

  contacts 20, 22; 20, 24 during the relaxation phase of the spring 58.

  Figures 2 to 5 show the changeover relay 10 of Figure 1 equipped in addition to a test button 70 in front of which moves an indicator 72 of the position of the contacts 20, 22; 20, 24. The manually-operated test button 70 passes through a passage opening 74 in the front face 76 of the housing 12, and serves to mechanically actuate the pallet 38 in the direction of approach with the pole surface 54, so as to transmit a rocking movement of the balance 44, and therefore a change of state of the movable contact 20 following each depression of the

test button 70.

  s 2709370 Inside the test button 70 is arranged an optical prism 78 cooperating with a feeler 80 of position integral with the pallet 38. The feeler 80 carries a first colored marker 82 which moves in translation along the prism 78 while occupying two extreme positions depending on the location of the pallet 38. The test button 70, the prism 78, the feeler 80 and a return spring 86 are mounted in a support 88 secured to the housing 12. The support 88 carries a second

  color marker 84 different in color from the first marker 82.

  In the OFF position of FIG. 2 corresponding to the state of rest of the electromagnet 14, the contacts 20, 22 of the first series of contacts are open, and the other contacts 20, 24 of the second series are closed. The first marker 82 of the probe 80 is arranged opposite the inclined face of the prism 78, which reflects

  the coloring of the first marker 82 towards the head of the prism 78.

  In the ON position of FIG. 4 following a change of state of the contacts after excitation of the electromagnet 14, the magnetic attraction of the pallet 38 against the cylinder head 40 causes the probe 80 to descend. The second mark 84 of different coloring is found in the vicinity of the inclined face of the prism 78, followed by

  the reflection of the light beam towards the front face.

  In the two positions of FIGS. 2 and 3, the test button 70 is not actuated, and remains permanently protruding by the action of the return spring of the type to

compression 86.

  With reference to FIGS. 6 and 7, manual insertion of the test button 70 into the orifice 74 causes the rocker 44 to be forcibly rocked, and the state of the contacts to change. In this case, the signaling given by the indicator 72 is not correct, but nevertheless remains invisible since the operator hides the head of the prism

  78 as long as his finger pushes on the test button 70.

  It is clear that the indicator 72 and the test button 70 could be arranged differently without departing from the scope of the invention. A variant consists in particular of

  use an elongated prism and a probe with two different color markers.

  When the electromagnet is activated the indicator moves and shows its

second color 92.

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Claims (7)

  1.Electromagnetic relay housed in an insulating housing (12) containing: an electromagnet (14) with a pivoting ferromagnetic paddle (38), - a balance control mechanism (16) (44) pivotally mounted on an axis (46 ) between two extreme angular positions, - a control member secured to the pallet (38) and cooperating with the balance (44) to move it from one position to the other at each cycle of operation of the pallet (38), - an electric circuit (18) of power having a tilting contact (20) bistable driven by the balance (44), and cooperating with at least one fixed contact (22, 24), - and an elastic device (56) for recalling the pallet (38) towards the separated position in the state of rest of the electromagnet (14), characterized in that the control member comprises a connecting rod (48) articulated on the pallet (38) and the pendulum (44) to form a permanent direct connection, the articulation point (50) of the link (4 8) on the balance (44) being offset relative to the pivot axis (46).   2. Electromagnetic relay according to claim 1, characterized in that the elastic return device (56) comprises a pair of compression springs (58, 60) acting successively on the underside of the pallet (38), and extending parallel to each other and to the link (48) in a direction   substantially perpendicular to the pallet (38).   3. Electromagnetic relay according to claim 1 or 2, characterized in that the front face of the housing (12) comprises an orifice (74) for passage of a test button (70) with manual control of the balance wheel (44), and qu '' an indicator (72) of position of   contacts is integrated inside the test button (70).   4. Electric relay according to claim 3, characterized in that the indicator (72) is composed of an optical prism (78) cooperating with a feeler (80) integral with the 7 2709370   pallet (38), the feeler having at least one indication mark (82, 92) capable of cooperating with the inclined face of the prism (78) according to the position drawn or moved away of the pallet (38).   5. electromagnetic relay according to claim 3 or 4, characterized in that the indicator (72) comprises two marks (82, 84) of different colors, and that the prism (78) is arranged to reflect the colored beam of each mark (82, 84) in direction of the front face.   6. electromagnetic relay according to claim 4 or 5 characterized in that a spring (86) is arranged between the pallet (38) and the front face of the housing (12) to urge the test button (70) towards a projecting position authorizing operation reliable indicator (72).   7. Electromagnetic relay according to claim 2, characterized in that the shortest first spring (58) located between the link (48) and the second spring   (60) has a hardness greater than that of said second spring.