FR2686453A1 - Differential switch - Google Patents

Abstract

This is a differential switch of the type including a rapid-disengaging mechanism in a box, between an operating handle (11) and a contact support (12). According to the invention, and in combination, the rapid-disengaging mechanism belongs, with the operating handle (11), to a first unit subassembly (A) which is appropriately set up with respect to the box (10) and to which there also belongs a sensitive relay (18), the contact support (12) by itself, with the moving contacts which it carries, forms a second unit subassembly (B) which, mounted rotatably on the box (10), is linked to the first by a U-shaped pin (38), and the differential transformer driving the sensitive relay (18) itself belongs to a third unit subassembly (C), which, appropriately set up with respect to the box (10), is linked to the second by electrical conductors.

Description

"Differential Switch"
The present invention relates generally to differential switches of the type usually used in certain electrical installations to ensure the safety of goods and people with regard in particular to possible leakage currents due to any faults of 'insulation.

 When such a leakage current is detected, they switch off the relevant electrical installation.

The present invention relates more particularly to the case where, as described in the French patent filed under
No. 88 01242 on February 3, 1988 published under No. 2.626.712, the differential switch implemented comprises, overall, in a housing, between a lever mounted rotatably relative to this housing and a contact support, which also mounted rotatably with respect thereto, carries at least two contacts, hereinafter referred to as simple convenience movable contacts, a mechanism with sudden release, which, capable of causing the automatic pivoting of this contact support between a position, engaged, closing, for which each applies these two movable contacts respectively against two fixed contacts, and a position, triggered, opening, for which these movable contacts are separated from the fixed contacts, is dependent on a sensitive relay piloted by a differential transformer established between input terminals and output terminals between which intervene the fixed contacts and the movable contacts.

 In French patent No 88 01242, the abruptly triggered mechanism is organized around a cam, which, in association with pawls, constitutes the locking device necessary to maintain the assembly in the locked closing position in the absence of default.

 However, as a variant, it can be organized around a toggle locking device using three axes, one of which must cross the alignment of the other two in neutral gear for this maintenance.

 Be that as it may, differential switches of this type are usually of a non-negligible cost, which, by increasing that of the electrical installations to which they are applied, slows development.

 The main object of the present invention is a general arrangement capable of lowering the cost of these differential switches by facilitating their mounting, whether this mounting is done manually or whether it is wholly or partly automated.

 According to this general arrangement, the present invention relates more specifically to a differential switch, which, of the type concerned, is characterized in that, in combination, the mechanism with sudden release belongs, with the operating lever, to a first unitary sub-assembly, which is duly wedged with respect to the housing and to which the sensitive relay also belongs, the contact support forms by itself, with the movable contacts which it carries, a second unitary sub-assembly, which , rotatably mounted on the housing, is connected to the first by a U-shaped pin subjected to a toggle locking device controlled by the operating lever, and the differential transformer itself belongs to a third unitary sub-assembly, which, duly wedged relative to the housing, is connected to the second by electrical conductors, in practice metallic braids.

 In short, according to this arrangement, the differential switch according to the invention is essentially organized in unitary sub-assemblies which are easy to assemble and advantageously capable of being put into place in the housing by simple engagement, interlocking or snap-fastening.

 In addition, the assembly with respect to each other of the various constituents of the main of these unitary subassemblies is advantageously only by stacking.

 Thus, overall, the assembly of the assembly advantageously only involves commitments, sockets, snaps or welds, without the intervention of any screw.

 This assembly is facilitated, for the benefit of the cost price.

 The present invention also alternatively relates to various arrangements which, made to one or other of the constituents to be used, also lead to a lowering of the cost price.

The characteristics and advantages of the invention will become apparent from the description which follows, by way of example, with reference to the appended schematic drawings in which
Figure 1 is a perspective view of a differential switch according to the invention
Figure 2 is a larger exploded perspective view, open housing
Figure 3 is a second exploded perspective view, housing cover removed
Figure 4 is a third exploded perspective view, limited to only some of the unitary subassemblies which it comprises
Figure 5 is a first exploded perspective view of the unitary sub-assembly absent from Figure 4
Figure 6 is, with a local cutaway, a more detailed exploded perspective view of the same unitary sub-assembly;
Figures 7 and 8 are perspective views illustrating two successive phases of a particular method of mounting two components of this unitary sub-assembly
Figure 9 is, on a larger scale, a perspective view of one of the unitary sub-assemblies present in Figure 4, shown in isolation
Figure 10 is an exploded perspective view of this unitary sub-assembly
Figures 11 and 12 are, on a still larger scale, cross-sectional views, which, each taken respectively along the line XI-XI, which is a broken line, and the line XII-XII of Figure 9, illustrate two successive phases of the assembly of this unitary sub-assembly
Figure 13 is, according to arrow XIII of Figure 2, and with local cutaways, an elevational view of the differential switch according to the invention, housing cover removed
Figure 14 is, along the line XIV-XIV of Figure 6, and on a larger scale, a cross-sectional view of the trigger indicator that includes this differential switch
Figure 15 is, with a local cutaway, and according to arrow XV of Figure 2, an elevational view of its operating handle, in the position which is hers for the establishment of the cover of its housing
Figure 16 is, according to arrow XVI of Figure 2, and on a larger scale, a view of its mechanism with sudden release, for the triggered open position
Figure 17 is a view similar to that of Figure 16, for an intermediate position between the triggered opening position and the latched closed position
Figure 18 is a view similar to the previous two, for the latched closed position
Figure 19 is an elevational view which, partly taking that of Figure 13, relates to an alternative embodiment.

 As illustrated in these figures, the differential switch according to the invention comprises, in a housing 10, between an operating lever 11 rotatably mounted relative to this housing 10 and a contact support 12, which also rotatably mounted relative to the housing 10, carries at least two contacts 13A, 13B, here called for simple convenience movable contacts, an abrupt trigger mechanism 15, detailed below, which, capable of causing the automatic pivoting of the contact support 12 between a position, engaged, closed, Figure 18, for which each applies the two movable contacts 13A, 13B respectively against two fixed contacts 16A, 16B, and a position, triggered, open, Figure 16, for which these movable contacts 13A , 13B are moved away from these fixed contacts 16A, 16B, is under the dependence of a sensitive relay 18 controlled by a differential transformer 19 established between input terminals 20A, 20B and output terminals 21A, 21B between which the fixed contacts 16A, 16B and the movable contacts 13A, 13B intervene.

 In the embodiment shown, the housing 10 is formed of a base 22, which, in the form of a box body, constitutes its lower part, and of a cover 23, which, adapted to cooperate in interlocking with the base 22, constitutes the upper part thereof.

 In a manner known per se, it is presented in modular form, and it is equipped, on the underside, with a lock 24 suitable for snapping onto a standardized rail, and, on the front, with a label protector 25.

 In a manner also known per se, the input terminals 20A, 20B and the output terminals 21A, 21B each have a bracket 26 and a clamping screw 27.

 Recesses 28 provided laterally in the housing 10 give access to the stirrups 26.

 On the front, the housing 10 also has recesses 30 giving access to their clamping screw 27.

 On the front, the housing 10 also has a recess 32 for the passage of the operating lever 11 and a recess 33 for leaving a trigger indicator 34 visible.

 These various arrangements are well known in themselves, and are not specifically part of the present invention, they will not be described in more detail here.

 It will suffice to indicate that the base 22 and the cover 23 of this housing 10 are fitted to each other in an assembly using a rebate 36 on the base 22, FIG. 2, and that the joint plane 37 corresponding flush with the upper level of the recesses 28, these thus forming simple notches for the base 22, FIG. 1.

 According to the invention, and in combination, the snap-action mechanism 15 belongs, with the operating lever 11, to a first unitary sub-assembly A, which is duly calibrated relative to the housing 10 and to which also the sensitive relay 18 , the contact support 12 forms by itself, with the movable contacts 13A, 13B which it carries, a second unitary sub-assembly B, which, also rotatably mounted on the housing 10, is connected to the first sub-assembly unit A by a U-shaped pin 38 subjected to a toggle locking device 40 controlled by the operating lever 11, and the differential transformer 19 itself belongs to a third unit sub-assembly C, which, duly calibrated relative to the housing 10 is connected to the second by electrical conductors 41A, 41B, in this case simple metal braids.

 In practice, the third unitary sub-assembly C is simply fitted into the base 22 of the housing 10, and the first and second A, B are snapped onto it.

 More precisely, and according to methods described in more detail later, the first and second unitary sub-assemblies A, B are snapped onto lugs 42, which, coming in one piece from the base 22 of the housing 10, perpendicular to the bottom of that these protrude upwards into the cover 23, counting from the longitudinal edges 43 of the base 22.

 The first unitary sub-assembly A comprises, parallel to each other, a flange 44 and a plate 45, which are duly secured to one another, and between which the operating lever 11 and the snap-action mechanism 15, Figure 5.

 The flange 44 is preferably made of synthetic material, and the plate 45 is for example made of metal.

 They are connected to each other by various spacers 46, which, coming in one piece from the flange 44, FIG. 6, cross after a shoulder 48 the plate 45 by means of recesses 47 thereof and are duly crimped by pins 49 beyond this plate 45.

 In practice, these are spacers which, over at least part of their length, are of circular cross section, and at least some of which thus serve as axes of rotation for various components present between the flange 44 and the plate 45 , and, in particular, with the operating lever 11.

 All perpendicular to the flange 44, they are parallel to each other.

 The flange 44 further carries projecting, perpendicular to its plane, and on either side of it, arms 50 which, each having at their end a lug 51, are suitable for the latching of the unitary subassembly A on the tabs 42 of the base 22 of the housing 10, these tabs 42 each having for this purpose a recess 53 of complementary contour and preceded by an engagement chamfer 54.

 The arms 50 of the flange 44 also each have a lug 52 which, for one of them, is engaged on a hook 52 ′ of the plate 45, on a first side of the latter, and which, for the 'other, crosses a recess 52 "of the plate 45, on the other side thereof, thereby forming a centering pin.

 The snap-action mechanism 15 comprises a latching rocker 55, which, rotatably mounted, by pins 56, between the flange 44 and the plate 45, this flange 44 and this plate 45 each comprising for this purpose a contour recess 57 circular, has a buttonhole 58 and a spout 59, a hooking lever 60, which, also rotatably mounted between the flange 44 and the plate 45, while being engaged on a spacer 46, has a shoulder 61 and an arm 62, and which is subjected to elastic means which urge it in the direction of a position for which its shoulder 61 interferes with the path of the spout 59 of the latching lever 55, a trigger lever 64, which, too, rotatably mounted between the flange 44 and the plate 45 have two arms, namely an arm 65 on which the sensitive relay 18 can act and an arm 66 by which it can act on the latching lever 60 in the direction for which it s aside from the toggle rocking 55, and which is itself subjected to elastic means which urge it in the direction of the sensitive relay 18, and a link 68, which, articulated to the operating lever 11 at one of its ends and to a branch 69 from the U-shaped pin 38 to the other of these, forms with the operating lever 11 the toggle locking device 40, said branch 69 of the U-shaped pin 38 passing through the buttonhole 58 of the toggle hooking 55 while its other branch 70 is articulated to the contact support 12.

 In the embodiment shown, the buttonhole 58 of the latching lever 55 is bent and the elastic means associated with the latching lever 60 are constituted by an elastically deformable finger 72 which this cantilever lever has in cantilever attachment 60 parallel to its axis of rotation and the free end of which is in abutment in a blind recess 73 provided for this purpose on the flange 44, FIG. 6.

 The support of the arm 62 of this latching lever 60 on the arm 66 of the trigger lever 64 is done by means of a screw 74 making it possible to adjust the position relative to the latter.

 In practice, the attachment lever 60 and the trigger lever 64 are coaxial.

 They are in fact engaged on the same spacer 46.

 Level with its arm 62, but on the opposite side thereof, the hooking lever 60 has a protruding lug 62 'projecting therefrom.

 In addition, on the side of its axis of rotation opposite to its arm 62, it has a finger 62 ".

 On the side opposite the latching lever 60, the trigger lever 64 has, transversely, meanwhile, a step 64 '.

 The snap-action mechanism 15 also includes a reset lever 75, which, rotatably mounted, has an arm 76 interposed on the path of a lug 77 which radially protrudes, for this purpose, the operating lever 11, and which , by a pin 78, is coupled to the trigger lever 64 by a spring 79 constituting the elastic means associated with this trigger lever 64, this trigger lever 64 itself being equipped with a pin 80 for this purpose.

 Between its spike 78 and its axis of rotation, the reset lever has another spike 75 '.

 In practice, the reset lever 75 and the trigger lever 64 are coaxial.

 This resetting lever 75 is in fact engaged on the same spacer 46 as the latching lever 60 and that the triggering lever 64.

 More precisely, the reset lever 75 constitutes, with the trigger lever 64 and the spring 79, a sub-assembly capable of being engaged individually on this spacer 46.

 To do this, the trigger lever 64 is rotatably engaged by a bore 64 "on a hub 75" by which the reset lever is itself rotatably mounted on the spacer 46 in question.

 During assembly, the trigger lever 64 and the reset lever 75 are first angularly arranged in a relative angular position for which, in FIG. 7, their respective pins 80, 78 are substantially at the spacing of the ends of the spring 79, not stretched, which advantageously facilitates the positioning thereof.

 The spike 75 'of the reset lever 75 then forms, in a first direction, an angular positioning stop for the assembly, and, this reset lever 75 bearing on the thickest part of the trigger lever 64, its hub 75 "is not yet fully engaged axially in the bore 64" thereof.

 The trigger lever 64 and the reset lever 75 are then angularly separated from each other against the spring 79, until, by virtue of the release 64 ′ of the trigger lever 64, the resetting lever 75 can move axially towards this trigger lever 64, thereby completing the engagement of its hub 75 "in the bore 64" thereof.

 Under the bias of the spring 79, then tensioned, the reset lever 75 comes into angular abutment by its edge 78 'against the trigger lever 64, in the opposite direction to the previous one, when the assembly is released, which, by simple support, makes this assembly integral, FIG. 8.

 The establishment, on the spacer 46 concerned, of the subassembly thus formed, is facilitated.

 The operating lever 11, which is rotatably mounted on a pillar 46 ′ parallel to the spacers 46 and which, like them, comes in one piece from the flange 44, carries in one piece, in the eccentric position, an axis 81 by which the connecting rod 68 is articulated to him.

 It is also subjected to a torsion spring 82, the central torsion part 83 of which is coaxial with its axis of rotation, and which urges it permanently into the triggered open position.

 In the embodiment shown, one, 84, of the branches of this torsion spring 82 is supported on a lug 85 which, integral with the plate 45, came by a puncture thereof, and the other, 86, of these branches is supported on an axis which, integral with the operating lever 11, is in the eccentric position thereon.

 In practice, this is the axis 81 by which the link 68 is articulated on the operating lever 11, which jointly ensures the maintenance of this link 68.

 Preferably, and as shown, the axis 81 has a notch for the at least partial engagement of this branch 86 of the torsion spring 82.

 In addition, in this embodiment, the operating handle 11 has, axially, for the engagement of the median torsion 83 of the torsion spring 82, a stud 87, which, by a pin 88, is engaged with a recess 89 in the plate 45.

 Thus, the axis of rotation of the operating lever 11 is formed jointly by the pillar 46 'of the flange 44 and by the pin 88 of its stud 87.

 It will therefore be designated below by the axis 88-46 '.

 In practice, and for reasons which will appear below, the lug 62 'of the attachment lever 60 and the tab 85 of the plate 45 are substantially arranged in the same plane, parallel to the latter.

 For its engagement on the axis 81 carried by the operating lever 11, the connecting rod 68 has a first ear 90.

For his commitment to branch 69 of the pin in
U 38 it has a second ear 91.

 The first unitary sub-assembly A further comprises, between the flange 44 and the plate 45, the trigger indicator 34.

 This trigger indicator 34 is rotatably mounted on a spacer 46, and it is locked in rotation on the contact support 12.

 In practice, it meshes with this contact support 12 by a toothing which, in the embodiment shown, implements, on the trigger indicator 34, a yoke 93, FIG. 14, and, on the contact support 12 , tooth 94, Figure 10.

 In practice, too, the trigger indicator 34 is subjected to elastic means which, for mounting the unitary sub-assembly A, urge it towards a determined neutral position when it is not in engagement with the tooth 94 of the contact support 12.

 In the embodiment shown, these elastic means consist of an elastically deformable finger 95 that this cantilever indicator 34 has in cantilever parallel to its axis of rotation and the free end of which is in abutment in a recess 96 provided for this purpose on the flange 44.

 The first unitary sub-assembly A comprises, finally, between the flange 44 and the plate 45, a retaining lever 97, which, rotatably mounted, comprises, on the one hand, a spout 98, interposed, in one direction, on the path of a spout 99 of the contact support 12, and, on the other hand, an arm 100 interposed, in the opposite direction to the previous one, on the path of the lug 77 of the operating lever 11.

 As will be noted, the lug 77 by which the operating lever 11 is able to act on the reset lever 75 is thus the same as that by which it is able to act on the retaining lever 97.

 For reasons which will appear below, this lug 77 has, on its lower surface, a step 77 ′, FIG. 15.

 In the embodiment shown, the retaining lever 97 is coaxial with the trigger indicator 34.

 It is in fact engaged on the same spacer 46 as this one.

 In practice, the retaining lever 97 is subjected to elastic means which permanently urge it towards a determined stop position.

 In the embodiment shown, these elastic means are constituted by an elastically deformable appendage 101 which is laterally cantilevered this retaining lever 97, parallel to its axis of rotation, on the side thereof opposite its beak 98 and its arm 100, and the free end of which abuts on a shoulder 102 of the flange 44.

 In the embodiment shown, this elastically deformable appendage 101 is folded into a U on itself.

 In its stop position, the retaining lever 97 is supported by a shoulder 103 against a shoulder 104 of the flange 44.

 As will be noted, the placing of the various constituents present between the flange 44 and the plate 45 can advantageously be done by simple stacking, perpendicular to this flange 44.

 At the end of this stacking, the branch 84 of the torsion spring 82 of the operating lever 11, the length of which is made sufficient for this purpose, is temporarily engaged on the lug 62 'of the latching lever 60, which maintains axially, on the corresponding spacer 46, the reset 75, trigger 64, and hook 60 levers which are engaged therein.

 I1 suffices, after the installation of the plate 45, to act on the finger 62 "of the hooking lever 60, so that, after having escaped from the lug 62 'thereof, the branch 84 of the spring torsion 82 comes of itself in engagement with the tab 85 of the plate 45, which then jointly ensures the maintenance thereof, even before the crimping of the pins 49 of the spacers 46.

 The manipulations of the unitary sub-assembly A are advantageously facilitated, and the assembly can advantageously be automated.

 In the embodiment shown, the sensitive relay 18 also belonging to the first unitary sub-assembly A is attached to the flange 44 on the face of this flange 44 opposite the plate 45.

 In other words, it extends to the back of this flange 44.

 Therefore, in order to be able to be actuated by its plunger core 105, the arm 65 of the trigger lever 64 extends, in a cap, far beyond the flange 44, at a distance from the edge of the latter, and therefore , without interference with this flange 44.

 In the embodiment shown, the sensitive relay 18 is disposed in a support 106 which is engaged with the flange 44 by a slide assembly.

 In practice, this support 106 is metallic.

 I1 is a simple blank suitably cut and folded, of which, on the one hand, the side edges 107 form slides engaged in sliding in grooves 108 of the flange 44, Figure 11, and in which, on the other hand , is formed a tab 109 provided with a recess 110 for its snap-fastening on a pin 111 provided for this purpose on this flange 44.

 The establishment of the sensitive relay 18, suitably disposed in its support 106, is thus done very simply, by simple engagement in the grooves 108 of the flange 44, until the tab 109 of this support 106 comes to snap onto the pin 111 of this flange 44.

 In the embodiment shown, the flange 44 also carries, on the sensitive relay 18 side, a printed circuit board 112 which, by holes 113, is duly attached, by crimping or force fitting, on pins 114 provided for this purpose projecting from this flange 44.

 The printed circuit board 112 usually carries various conductive strips and various functional components.

 In the embodiment more particularly represented in FIGS. 1 to 15, and as it is better visible in FIG. 3, there is thus connected to it a wire 115 intended to intervene, according to arrangements described in more detail later, in a testing device.

 In the embodiment shown, the contact support 12 is formed from two parts 12 ′, 12 ", which, rotatably mounted relative to one another against elastic spacing means, are snapped into place. 'to one another with prestressing of these elastic spacing means, namely, a first part 12', which, carrying movable contacts 13A, 13B, has laterally journals 116A, 116B by which the assembly is rotatably mounted on the housing 10, and, more precisely, on two legs 42 of the base 22 thereof having for this purpose two recesses 118A, 118B of circular outline each preceded by an engagement chamfer 117, and a second part 12 " , on which the U-shaped pin acts 38.

 It is, in practice, the part 12 ′ which comprises the tooth 94 necessary for driving the trigger indicator 34, and the spout 99 intended to cooperate with the retaining lever 97.

 This tooth 94 and this beak 99 are formed on the edge of a veil 119, which, perpendicular to the pins 116A, 116B, extends substantially between them.

 Parallel to the pins 116A, 116B extends a curved blade 120, which, duly connected to the pins 116A, 116B, in particular by the web 119, is intended to provide support for the movable contacts 13A, 13B.

 Parallel to the journals 116A, 116B of the part 12 ', the part 12 "has a hole 121 for the rotational engagement of the branch 70 of the U-shaped pin 38.

 For each of the movable contacts 13A, 13B, this part 12 "has, in addition, parallel to one another, two flanges 122A, 122B, which, at their base, are each provided with a spout 124 for guiding of these movable contacts 13A, 13B and which, at their other end, and for reasons explained later, are connected to each other by a cross member 125A, 125B.

 The movable contacts 13A, 13B, which are identical to each other, each have an extension 126A, 126B, in the form of an S, by a corrugation 127 from which they bypass in one direction the corresponding pin 116A, 116B of the first part 12 ′ of the contact support 12, and by the other corrugation 128 from which they bypass, in the opposite direction to the previous one, the crosspiece 125A, 125B which the second part 12 ″ of this contact support 12 has in correspondence.

 As a corollary, the elastic spacing means interposed between the two parts 12 ′, 12 "thus constituting the contact support 12 are constituted by two torsion springs 130A, 130B, which, due to one by movable contact 13A, 13B, are each individually engaged, by their central torsion part 131, on the journal 116A, 116B corresponding to the first 12 'of these parts, and whose branches 132, which are parallel to each other, are passed under the corresponding crosspiece 125A, 125B on the other 12 ", of these parts, while their middle part 133 relates to the movable contact 13A, 13B associated, on the back of the latter.

 For the temporary retention, during assembly, of these torsion springs 130A, 130B, the movable contacts 13A, 13B each comprise, laterally, on their corrugation 128, two shoulders 135 suitable for each serving respectively as a stop for the two branches 132 of these torsion springs 130A, 130B.

 Beyond these shoulders

 For its articulation with the first part 12 ′ of the contact support 12, the second part 12 ″ of the latter is in simple bearing contact, by notches 138A, 138B in the form of a gutter, against the pins 116A, 116B of this first piece 12 '.

 Finally, for its engagement on the flange 44, the contact support 12 has transversely, in its middle part, a notch 139, which affects both of its component parts 12 ′, 12 ″, at the edge of the web 119 of the part 12 ′, and which intervenes between the cross members 125A, 125B of the part 12 ".

 For mounting the contact support 12 thus formed, it can for example be carried out as follows.

 Each of the torsion springs 130A, 130B is first engaged on the corresponding pin 116A, 116B of the part 12 'with the movable contact 13A, 13B with which it is associated, this movable contact 13A, 13B being inserted by its undulation 127 between this pin 116A, 116B and the curved blade 120.

 The branches 132 of the torsion springs 130A, 130B are supported on the shoulders 135 of the movable contacts 13A, 13B, FIG. 11.

 The part 12 "is then engaged, by its crosspieces 125A, 125B, on the movable contacts 13A, 13B, in the hollow of the second corrugation 128 thereof, FIG. 11.

 It is then folded down in the direction of the part 12 ′, along the arrow F1 in FIG. 11, until, as indicated in FIG. 12, a beak 140 which it presents for this purpose comes to be hooked on a beak 141 that this part 12 'has in correspondence for the same purpose.

 At the end of this folding, the part 12 "carries by its notches 138A, 138B on the pins 116A, 116B of the part 12 ', and the torsion springs 130A, 130B are under prestressing.

 As indicated above, the third unitary sub-assembly C comprises a differential transformer 19.

 In practice, the torus thereof, not visible in the figures, is housed in a casing 143 having transversely, on its underside, flanges 144 by which it can be inserted in grooves 145 provided for this purpose projecting from the inner surface of the side walls 146 of the base 22 of the housing 10.

 The primary of this differential transformer 19 is formed of two large windings 147A, 147B, in strip, at the rate of one by movable contact 13A, 13B.

 At one of their ends, these windings 147A, 147B are each respectively connected to the movable contacts 13A, 13B by the electrical conductors 41A, 41B.

 At their other end, they each carry, respectively, in a coplanar manner, tongues 152A, 152B, which are themselves each respectively engaged in the output terminals 21A, 21B, and, more precisely, in the bracket 26 of these terminals. outlet 21A, 21B, under their clamping screw 27.

 In other words, the third unitary sub-assembly C comprises tongues 152A, 152B integral with the primary windings 147A, 147B of the differential transformer 19.

 In practice, these tabs 152A, 152B are attached by welding to the primary windings 147A, 147B, and, likewise, the electrical conductors 41A, 41B are secured by welding to these primary windings 147A, 147B as well as to the movable contacts 13A , 13B.

 In practice, also, the tongues 152A, 152B have at their root a portion of lesser width 153 by which they are each embedded respectively in a notch 154 provided for this purpose on a transverse partition 155A, 155B of the base 22 of the housing 10 of which only one is visible in the figures.

 Legs of the cover 23, not visible in the figures, press these tabs 152A, 152B on the bottom of these notches 154.

 Thus, the retention, in the housing 10, of the tongues 152A, 152B, and, therefore, that of the unitary subassembly C as a whole, are ensured by simple interlocking and pinching.

 The secondary, fine winding 150 of the differential transformer 19 is connected to the terminals of the sensitive relay 18, possibly via the printed circuit board 112, and, more precisely, a conductive strip thereof. .

 As for the fixed contacts 16A, 16B, they each belong respectively to parts 156A, 156B, which have a U-shaped part 158 by which they are engaged, by pinching, on a transverse partition 159 of the base 22 of the housing 10, and which, on the opposite side to the fixed contacts 16A, 16B concerned, are extended by a tab 160A, 160B which, like the previous tabs 152A, 152B, is engaged in the corresponding input terminal 20A, 20B, and, more precisely , in the bracket 26 of this input terminal 20A, 20B, under the clamping screw 27 thereof.

 As indicated above, and in a manner known per se, the differential switch according to the invention is completed by a test circuit.

 This is under the control of a push button 162 available to the user on the front of the housing 10.

 In practice, this push button 162 is mounted movable in translation against elastic means which permanently urge it in the direction of a rest position for which the test device is off.

 In the embodiment shown, and according to the invention, the elastic means thus associated with this push button 162 are constituted by a corrugated appendage 163, which came integrally with it, under its underside, between two legs 164 suitable for defining by snap-fastening the rest position on the housing 10, and the free end of which abuts this housing 10.

 According to the invention, also, the push-button 162 carries a metal jumper 165 adapted by its two branches 166, 167 to be able to connect together, when pressed, two closing terminals allowing the commissioning of the device. test.

 One of these closing terminals, on which the branch 167 acts, is formed by one of the movable contacts 13A, 13B, and, more precisely, by the movable contact 13B.

 In practice, in the embodiment shown, this first closing terminal is formed by the spout 137B of the extension 126B of this movable contact 13B.

 In the embodiment shown in FIGS. 1 to 15, the other closing terminal of the test device, on which the branch 166 of the metal jumper 165 acts, is formed by the wire 115 provided for this purpose.

 As a variant, in FIG. 16, it is formed by the support 106 of the sensitive relay 18.

 Indeed, in this variant, this support 106 carries locally by a tab 170 on the printed circuit board 112, and, more precisely, on a conductive strip 171 thereof.

 During assembly, first of all, the fixed contacts 16A, 16B are put into place in the base 22 of the housing 10, by simple stacking of these fixed contacts 16A, 16B, and input terminals 20A, 20B which associated with them, in this base 22.

 I1 is then proceeded to the establishment of the third unitary sub-assembly C, by simple stacking of this third unitary sub-assembly C, and of the output terminals 21A, 21B which are associated with it, in the base 22.

 I1 is then proceeded to the establishment of the second unitary sub-assembly B, attached, by the electrical conductors 41A, 41B, to the third unitary sub-assembly C above.

 This implementation is done simply by snap-fastening, in the recesses 118A, 118B of the lugs 42 concerned of the base 22, of the pins 116A, 116B of the contact support 12 forming this second unitary sub-assembly B, with insertion of a spring d spacing 173 between the part 12 "thereof and the bottom of a groove 174 provided for this purpose in the base 22.

 This spacer spring 173 normally maintains the movable contacts 13A, 13B carried by the contact support 12 away from the fixed contacts 16A, 16B.

 For its support, the part 12 "of the contact support 12 has, at its base, in its middle part, a lug 175, FIG. 12, projecting from a centering pin 176 on which it is engaged.

 I1 is then carried out, on the base 22, of the first unitary sub-assembly A, by snap-fastening of the lugs 51 of the latter in the recesses 53 of the legs 42 of the base 22.

 I1 is proceeded, finally, to the establishment of the U-shaped pin 38 by engagement of its branch 69 in the ear 91 of the link 68 through the buttonhole 58 of the latch 55 and engagement of its branch 70 in the bore 121 of the contact support 12.

 I1 then suffices to attach the cover 23 to this base 22, which is done by keeping the operating handle 11 substantially straight, as shown in FIG. 2, and to secure this cover 23 to the base 22.

 In practice, the right maintenance of the operating handle 11 is ensured by bringing the latter in engagement with the end 76 ′ of the arm 76 of the resetting lever 75 by the recess 77 ′ of its lug 77, FIG. 15.

 I1 then suffices to rotate it in the direction of this reset lever 75 so that, escaping therefrom, and under the stress of its torsion spring 82, it comes of itself in the triggered opening position. .

 The attachment of the cover 23 to the base 22 can for example be ensured by legs 177, which, coming in one piece from the base 22, pass through holes 178 provided for this purpose on the front of the cover 23 and are crimped beyond this one, figure 2.

 Alternatively, it can be carried out using screws.

 The push-button 162 of the test device can then be put in place, with the metal jumper 165 which it carries, by simple snap-fastening on the cover 23.

 It can also be placed before.

 The same applies to the label protector 25.

 It will be assumed that, starting from a triggered opening position shown in FIG. 16, there is a manual closing of the differential switch according to the invention, by tilting its operating lever 11 clockwise, such as shown schematically by arrow F2 in this figure 16.

 By the branch 69 of the U-shaped pin 38, which is engaged with the buttonhole 58 of the hooking lever 55, the link 68, then driven by the operating lever 11, causes the pivoting in the clockwise direction of this latching lever 55 by its pins 56, as shown diagrammatically by the arrow F3 in FIG. 16, which leads this latching lever 55 to come to be carried by its spout 59 against the shoulder 61 of the latching lever 60.

 The latching lever 55 being therefore blocked in rotation, the branch 69 of the U-shaped pin 38 is forced to follow its buttonhole 58 if the tilting action applied to the operating lever 11 is continued, so that, by its branch 70, this U-shaped pin 38, duly pushed as a result by the link 68, in turn causes the contact support 12 to pivot clockwise by the pins 116A, 116B of its part 12 ', as shown schematically by an arrow F4 in FIG. 16.

 During this pivoting, which, having regard to the stiffness of the elastic spacing means constituted by the torsion springs 130A, 130B, relates, initially, to both of the parts 12 ', 12 "constituting this contact support 12, the spout 99 of the part 12 'interferes with the spout 98 of the retaining lever 97, FIG. 17, which temporarily retains this part 12'.

 The tilting of the operating lever 11 being continued, the only one therefore continues to pivot, temporarily, around the pins 116A, 116B of the part 12 ', the part 12 ", which leads to an accentuation of the preload of the torsion springs 130A , 130B.

 Therefore, when, coming to carry by its lug 77 on the arm 100 of the retaining lever 97, the operating lever 11 rotates this retaining lever 97 counterclockwise, according to the arrow F5 of FIG. 17, this which releases the part 12 'from the contact support 12, this part 12', duly stressed by the elastic spacing means constituted by the torsion springs 130A, 130B, is applied abruptly against the fixed contacts 16A, 16B the movable contacts 13A , 13B which it carries.

 Conjointly, the axis 81 by which the rod 68 is articulated to the operating lever 11 crosses in neutral gear the alignment of the axis of rotation 88-46 'of this operating lever 11 with the axis of rotation that constitutes for the link 68 the branch 69 of the U-shaped pin 38, so that, by the toggle locking device 40 formed jointly by this operating lever 11 and this link 68, the abrupt trigger mechanism 15 is found locked, disengageably, in closing, and, with it, the operating lever 11 and all of the other components concerned.

 For the manual opening of the differential switch according to the invention, it suffices to return the operating lever 11 to its initial position, by tilting it counterclockwise, that is to say in the direction opposite to that marked by arrow F2 in FIG. 16.

 In fact, as soon as the axis 81 of the link 68 crosses again, passing neutral, but in the opposite direction to the previous one, the alignment of the axes 88-46 ′, 69 specified above, the whole is released.

 Under the bias of the torsion spring 82 constituting its elastic return means, the operating lever 11 then returns by itself to its initial position, driving with it the rod 68, and, jointly, the spacer spring 173 returns the contact support 12 to its initial position, the component parts 12 ′, 12 ″, then released, deviate from one another within the limits of their angular movement under the sole stress of the torsion spring 130A, 130B constituting the elastic spacing means associated therewith.

 By its tab 175, the part 12 "of the contact support 12 then comes to bear on a stop 180 provided for this purpose on the flange 44, FIG. 16.

 It will now be assumed that, the differential switch according to the invention being in the closed closing position shown in FIG. 18, there is a fault.

 Duly detected by the differential transformer 19, this fault causes the sensitive relay 18 to go into action.

 By its plunger core 105, this causes the clockwise pivoting of the trigger lever 64, and the latter driving in the same direction the latching lever 60, according to arrow F6 of FIG. 18, the rocker d hooking 55 is released.

 Under the stress of the torsion spring 82 constituting its elastic return means, the operating lever 11 returns by itself to its open position, which, as before, drives the axis of rotation 81 of the rod 68 to cross the alignment of axes 88-46 ', 69.

 The abrupt trigger mechanism 15 being thus unlocked, the assembly returns by itself to the triggered opening position according to the same process as that previously described.

 During its return to the initial position, the operating lever 11 comes to act by its lug 77 on the arm 76 of the reset lever 75.

 By means of the spring 79, this reset lever 75 then forces the trigger lever 64 to act by its arm 65 on the plunger core 105 of the sensitive relay 18, which causes the reset of the latter.

 As will be understood, this spring 79 advantageously forms in this respect a damping spring.

 Of course, the present invention is not limited to the embodiments described and shown, but encompasses any variant.

 In particular, the number of mobile contacts, and therefore of fixed contacts, obviously depends on the number of poles to be protected.

Claims (37)

 1. A differential switch of the kind comprising, in a housing (10), between an operating lever (11) rotatably mounted with respect to said housing (10) and a contact support (12), which, itself also rotatably mounted with respect to said housing (10), carries at least two contacts (13A, 13B), hereinafter called mobile contacts, a snap-action mechanism (15), which, capable of causing the automatic pivoting of said contact support (12) between a position, engaged , closing, for which each applies respectively the two movable contacts (13A, 13B) against two fixed contacts (16A, 16B), and a position, triggered, of opening, for which these movable contacts (13A, 13B) are separated from said fixed contacts (16A, 16B), is dependent on a sensitive relay (18) controlled by a differential transformer (19) established between input terminals (20A, 20B) and output terminals (21A, 21B) between which the fixed contacts (16A, 16B) and the movable contacts (13A, 13B), characterized in that, in combination, the snap-action mechanism (15) belongs, with the operating lever (11), to a first unitary sub-assembly (A) which is duly wedged with respect to the housing (10) and to which the sensitive relay (18) also belongs, the contact support (12) forms by itself, with the movable contacts (13A, 13B) which it carries, a second unitary sub-assembly (B), which, rotatably mounted on the housing (10), is connected to the first by a U-shaped pin (38) subjected to a toggle locking device (40) controlled by the operating lever (11 ), and the differential transformer (19) itself belongs to a third unitary sub-assembly (C), which, duly calibrated with respect to the housing (10), is connected to the second by electrical conductors (41A, 41B).  2. Differential switch according to claim 1, characterized in that, the housing (10) being formed by a base (22), which, in the form of a box body, constitutes its lower part, and a cover ( 23), which, adapted to cooperate in interlocking with the base (22), constitutes the upper part, the third unitary sub-assembly (C) is fitted in the base (22) and the first and second (A, B) are snapped into it.  3. Differential switch according to claim 2, characterized in that the first and second unit sub-assemblies (A, B) are snapped onto lugs (42) which, coming from the base (22) of the housing (10), protrude upwards in the cover (23) from the edges (43) of said base (22).  4. Differential switch according to any one of claims 1 to 3, characterized in that the first unitary sub-assembly (A) comprises, parallel to one another, a flange (44) and a plate (45) , which are duly secured to each other, and between which are arranged the operating lever (11) and the mechanism with abrupt release (15).  5. Differential switch according to claim 4, characterized in that the abruptly triggering mechanism (15) comprises a latching rocker (55), which, rotatably mounted, has a buttonhole (58) and a spout (59), a hooking lever (60), which also rotatably mounted, has a shoulder (61) and an arm (62), and which is subjected to elastic means which urge it towards a position for which its said shoulder (61) interferes with the path of the spout (59) of the hooking lever (55), a trigger lever (64), which, also rotatably mounted, has two arms, namely an arm (65) on which can act the sensitive relay (18) and an arm (66) by which it can act on said latching lever (60) in the direction for which it moves away from the latching latch (55), and which is itself subjected to elastic means which urge it in the direction of said sensitive relay (18), and a link (68), which, articulated ée to the operating handle (11) at one of its ends and to a branch (69) of the U-shaped pin (38) at the other thereof, formed with the operating handle (11) the toggle locking device (40), with said branch (69) of the U-shaped pin (38) which passes through the buttonhole (58) of the hooking lever (55) and the other (70) of the branches of this U-shaped pin (38) which is articulated to the contact support (12).  6. Differential switch according to claim 5, characterized in that the elastic means associated with the latching lever (60) are constituted by an elastically deformable finger (72) that has this latching lever overhanging (60 ) parallel to its axis of rotation and the free end of which is in abutment.  7. Differential switch according to any one of claims 5, 6, characterized in that the latching lever (60) and the trip lever (64) are coaxial.  8. Differential switch according to any one of claims 5 to 7, characterized in that the sudden release mechanism (15) comprises a reset lever (75), which, mounted rotatably, has an arm (76) interposed on the path of a lug (77) of the operating lever (11), and which is coupled to the trigger lever (64) by a spring (79) constituting the elastic means associated therewith.  9. Differential switch according to claim 8, characterized in that the reset lever (75) and the trip lever (64) are coaxial.  10. Differential switch according to any one of claims 4 to 7, characterized in that the sensitive relay (18) is attached to the flange (44) of the first unitary subassembly (A), on the face of this flange (44) opposite the plate (45) associated therewith.  11. Differential switch according to claim 10, characterized in that the sensitive relay (18) is arranged in a support (106) which is engaged with the flange (44) of the first unitary sub-assembly (A) by mounting to slides.  12. Differential switch according to any one of claims 10, 11, characterized in that, on the sensitive relay side (18), the flange (44) of the first unitary sub-assembly (A) also carries a printed circuit board (112).  13. Differential switch according to claim 12, characterized in that, a test device being provided, the support (106) of the sensitive relay (18), which is metallic, bears locally on the printed circuit board (112) and thus constitutes in itself a closing terminal for said test device.  14. Differential switch according to any one of claims 4 to 13, characterized in that the first unitary sub-assembly (A) also comprises a trigger indicator (34), which, mounted rotatably, is locked in rotation on the support contact (12).  15. Differential switch according to claim 14, characterized in that the trigger indicator (34) meshes with the contact support (12) by a toothing.  16. Differential switch according to any one of claims 14, 15, characterized in that, when it is not engaged with the contact support (12), the tripping indicator (34) is subjected to elastic means which, for mounting the first unitary sub-assembly (A), urge it towards a determined neutral position.  17. Differential switch according to claim 16, characterized in that said elastic means consist of an elastically deformable finger (95) which has the trigger indicator (34) in cantilever parallel to its axis of rotation and whose the free end is in abutment.  18. Differential switch according to any one of claims 4 to 17, characterized in that the first unitary sub-assembly (A) comprises a retaining lever (97), which, rotatably mounted, comprises, on the one hand, a spout (98), interposed in one direction on the path of a spout (99) of the contact support (12), and, on the other hand, an arm (100) interposed in the opposite direction to the previous one on the path of a lug (77) of the operating lever (11).  19. Differential switch according to claims 8 and 18, taken together, characterized in that the lug (77) by which the operating lever (11) is able to act on the reset lever (75) is the same as that by which it is able to act on the retaining lever (97).  20. Differential switch according to claims 14 and 18, taken together, characterized in that the retaining lever (97) is coaxial with the trigger indicator (34).  21. Differential switch according to any one of claims 18 to 20, characterized in that the retaining lever (97) is subjected to elastic means which permanently urge it towards a determined stop position.  22. Differential switch according to claim 21, characterized in that said elastic means consist of an elastically deformable appendage (101) which has the retaining lever (97) laterally in cantilever and whose free end is in stop.  23. Differential switch according to claim 5, characterized in that, the operating handle (11) being subjected to a torsion spring (82) whose median torsion part (83) is coaxial with its axis of rotation and which permanently requests in the triggered open position, one of the branches (84) of this torsion spring (82) is supported on a lug (85) secured to the plate (45) while the other (86) is supported on an axis (81) which, integral with the operating lever (11), is in the eccentric position thereon.  24. Differential switch according to claim 23, characterized in that said axis (81) is the axis by which the link (68) of the toggle locking device (40) is articulated to this operating lever (11).  25. Differential switch according to any one of claims 23, 24, characterized in that, for temporary engagement of the branch (84) of the torsion spring (82), the latching lever (60) has a lug (62 ') which, parallel to the plate (45), is substantially in the same plane as the tab (85) thereof.  26. The following differential switch, taken jointly, on the one hand, claim 8, and, on the other hand, any one of claims 23 to 25, characterized in that, for its maintenance right to mounting, the lever maneuver (11) has a recess (77 ') by which it is adapted to engage the end (76') of the arm (76) of the reset lever (75).  27. Differential switch according to claim 9, characterized in that the reset lever (75) and the trigger lever (64) constitute a sub-assembly, the trigger lever (64) being rotatably engaged by a bore (64 ") on a hub (75") of the reset lever (75).  28. Differential switch according to claim 27, characterized in that, under the bias of a spring (79) by which it is coupled to the release lever (64), the reset lever (75), in the subassembly that it forms with this trigger lever, abuts against it by its edge (78 ').  29. Differential switch according to any one of claims 1 to 28, characterized in that the contact support (12) is formed of two parts which, rotatably mounted relative to each other against means elastic spacers, are snapped to each other with preload of said elastic spacing means, namely a first part (12 ') which, carrying the movable contacts (13A, 13B), laterally has pins (116A , 116B) by which the assembly is rotatably mounted on the housing (10), and a second part (12 ") on which the U-shaped pin (38) acts.  30. Differential switch according to claim 29, characterized in that the movable contacts (13A, 13B) each comprise an extension (126A, 126B) in the form of an S, by a corrugation (127) from which they bypass the trunnion in one direction ( 116A, 116B) corresponding to the first part (12 ') of the contact support (12), and by the other corrugation (128) from which they bypass in the opposite direction to the previous one a crosspiece (125A, 125B) that has for this purpose in correspondence the second part (12 ") of this contact support (12).  31. Differential switch according to claim 30, characterized in that the elastic spacing means interposed between the two parts (12 ', 12 ") constituting the contact support (12) are constituted by two torsion springs (130A, 130B ), which, at the rate of one by movable contact (13A, 13B), are each individually engaged by their central torsion part (131) on the journal (116A, 116B) corresponding to the first (12 ') of said parts, and whose branches (132) are passed under the crosspiece (125A, 125B) corresponding to the other (12 ") of said parts.  32. Differential switch according to claim 31, characterized in that, for support of said torsion springs (130A, 130B), the movable contacts (13A, 13B) each comprise laterally two shoulders (135) on their extension (126A, 126B) .  33. Differential switch according to any one of claims 29 to 32, characterized in that, for its articulation with the first part (12 ') of the contact support (12), the second part (12 ") thereof is in simple contact contact against its pins (116A, 116B).  34. Differential switch according to claim 4, characterized in that, for its engagement on the flange (44) of the first unitary sub-assembly (A), the contact support (12) has transversely in its middle part a notch (139 ).  35. Differential switch according to any one of claims 1 to 34, characterized in that each of the fixed contacts (16A, 16B) belongs to a part (156A, 156B) which has a U-shaped part (158) by which it is engaged on a transverse partition (159) of the housing (10), and which is extended by a tongue (160A, 160B) engaged in the corresponding input terminal (20A, 20B).  36. Differential switch according to any one of claims 1 to 35, characterized in that the third unitary sub-assembly (C) comprises, integral with the primary windings (147A, 147B) of the differential transformer (19), tongues (152A , 152B) which are each respectively engaged in the output terminals (21A, 21B).  37. Differential switch according to any one of claims 1 to 36, characterized in that, a test device being provided under the control of a push button (162) available to the user, said button pusher (162) carries a metal jumper (165) adapted by its two branches (166, 167) to be able to connect together two closing terminals, one of which is formed by one of the movable contacts (13A, 13B) or an extension ( 126A, 126B) thereof.