FR2800507A1 - ROTARY ELECTRIC SWITCH, PARTICULARLY FOR A MOTOR VEHICLE WINDSCREEN WIPER MOTOR - Google Patents

Abstract

The invention provides a switch (10) which comprises a disc (12), one face of which comprises an electrical contact track (28, 29), an annular stop zone (ZA), a neutral annular zone (ZN), and a cam (40) which radially separates the contact track (28, 29) from the neutral zone (ZN), and which comprises a fixed contact blade (26), characterized in that the blade (36) cooperates with a face lateral (46) of the cam (40) when the disc (12) rotates in a first direction, being bent transversely as long as its free end (36) has not crossed the front end edge (42) of the contact track, and in that the blade (26) is in its free non-flexed transversely when its rear free end cooperates with the stop zone (ZA) and when it cooperates with the neutral zone (ZN). for stopping in the parking position of an engine for the alternating sweep drive of a motor vehicle wiper mechanism.

Description

B587 The present invention relates to a switch

electric rotary.

  The invention relates more particularly to a commu-

  rotary stop switch in position of an electric motor, in particular for stopping in the parking position of an engine for the drive in alternating wiping of a motor vehicle wiper mechanism, of the type which comprises : - a disc driven in rotation by the motor, an annular upper face of which comprises at least one track of electrical contact in conductive material in the form of an annular sector and which is angularly delimited by a front edge of the end of the track beyond which s 'angularly extends forward an annular nonconductive stop zone of electricity which extends angularly towards the rear, i5 parallel to the annular contact track, by a neutral annular nonconductive zone; - And a fixed contact blade which extends generally in a tangential direction, one front distal end of which is fixed and the other rear proximal free end of which is in particular capable of cooperating, depending on the angular position of the disc, either with the annular conductive contact track, either with the stopping zone and of the type in which the disc has on its upper face a cam which extends angularly from back to front until said edge before the end of contact track radially separates the annular contact track from the neutral annular zone, which is delimited radially by an internal lateral face and by an external lateral face, and with which the rear free end of the contact blade cooperates, forming a cam follower element, whether or not to cause the elastic deformation of the contact blade so as to cause it to flex transversely in a plane generally B587 parallel to the face s of the disc so that its rear free end moves radially to cooperate with the contact track when the disc rotates in a first direction, from back to front, and to cooperate with the neutral zone when the disc rotates in a second opposite direction . The neutral zone of such a switch, whether constituted by a recess or by a part made of insulating material, makes it possible to avoid the phenomenon of tremor or "bell" which occurs when one voluntarily applies to the arm of 'wiper, and therefore the electric motor and the disc of the switch which is linked in rotation to the motor, an effort tending to cause a rotation of the disc from back to front against its direction of rotation before its automatic stop. In such a case, the neutral zone and the cam which automatically guides the free end of the contact blade towards the neutral zone, make it possible to prevent the motor from inadvertently restarting forward and then stopping again when the the free end of the contact blade is

  again next to the stop zone, and so on.

  An example of such a switch is described and represented in document DE-A-4,228,492 in which the cam is a bent sheet metal strip which extends on the path of the rear end of the contact blade when

  the latter is in its free, uninflected state.

  It follows from this design that the blade alternately flexes in both directions in the event of a "ringing" and that, if the disc remains in a neutral angular position, the

  blade remains under elastic stress.

  In addition, the design proposed in this document does not make it possible to increase the neutral stroke, except by forcing the blade very elastically and on an angular stroke B587 which is too great during the normal stroke of

  works before the engine stops automatically.

  In order to remedy these drawbacks, the invention proposes a switch of the type mentioned above, characterized in that the blade cooperates with a lateral face of the cam when the disc rotates in the first direction, being bent transversely as long as its end free has not crossed, from back to front, the front edge of the end of the contact track, and the contact blade is in its free state io not bent transversely when on the one hand its rear free end cooperates with the stop area and when else

  apart, it cooperates with the neutral zone.

  According to other characteristics of the invention - the stopping zone is substantially coplanar with the contact track; - the neutral zone is shaped like a ramp - the height of the ramp gradually increases from front to back; - The neutral annular zone extends in a plane which is vertically offset upwards with respect to the plane of the contact track, and the front end edge of the contact track is formed into a stop with which the end cooperates free rear of the contact blade, of rounded conformation, to cause a vertical displacement upwards of this free end at a height corresponding to the altitude of the neutral annular zone; - Said lateral face of the cam is its internal lateral face, and the radius of this internal lateral face progressively decreases from its rear free end edge to its front free end edge - the cam is of substantially radial thickness constant over its entire length B587 - the annular stop zone and the neutral annular zone are two sections of tracks made of material insulating from electricity; - The contact blade extends substantially dan a vertical plane; - The body of the disc is a molded piece of electrically insulating material; - The periphery of the disc is shaped like a toothed pinion. Other characteristics and advantages of the invention

  will appear on reading the detailed description which will

  follow for the understanding of which reference will be made to the appended drawings in which: - Figure 1 is a schematic perspective view on a large scale of the two main components of a rotary electrical switch according to a first embodiment of the invention; - Figure 2 is a simplified view of Figure 1 in which the engine stop contact blade is shown in position of contact with the contact track; - Figure 3 is a top view, similar to that of Figure 2, illustrating the position of the contact blade when approaching the end of the contact track - Figure 4 is a view similar to that of the Figure 2 which illustrates the position of the contact blade in the engine stop position; - Figure 5 is a view similar to those of Figures 2 and 4 in which the contact blade is illustrated in cooperation with the neutral annular zone - Figures 6 to 9 are views similar to those of Figures 2 to 5 which illustrate a second embodiment B587 of an electric switch in accordance with the teachings of the invention.

  In the description which follows, as well as in the

  claims, the terms will be used without limitation

  vertical, horizontal, upper, lower, front, rear in

  reference to the figures and to simplify the description.

  There is shown in Figure 1 a rotary electrical switch 10 consisting essentially, and in known manner, by a disc 12 mounted rotating in two directions around a vertical axis A and by a contact holder 14 arranged here

  vertically above the disc 12.

  The rotating disc 12 is for example a part of generally annular shape molded from insulating plastic material and it is rotated in both directions by an attached hub 16 while its periphery can be provided with a toothed crown 18 which is integral therewith. rotating so

to constitute a toothed pinion.

  The toothed pinion 18 belongs for example to a geared motor assembly for the alternating sweep drive of a wiper mechanism, the toothed pinion being able to be mounted directly on the output shaft of the electric motor (not shown) of the geared motor. , or belong to a cascade of pinions and toothed wheels of the gearmotor. The contact carrier 14 consists of an insulating plastic body 20 which is for example molded around three electrical contact blades 22, 24 and 26 which, from the insulating support 20 which is fixed relative to the disc 12, s' generally extend vertically downward and in a generally tangential orientation towards the face

upper annular disc 12.

  B587 The three contact blades 22, 24 and 26 are produced by cutting and folding a conductive sheet and are thus produced in the form of elastically deformable elements to ensure electrical contact with different zones or parts of a rotating disc 12 as will be explained later. This annular upper face is provided with a coating of conductive material, which is for example produced in the form of a metal plate constituting an insert, or by a metallization layer in general form

  ring to constitute an annular contact track 28.

  Radially inwards, the annular contact track 28 delimits an annular track constituted by the surface of insulating material 30 of the body of the disc 12 and with which the bottom end 23 of the

first contact blade 22.

  As can be seen in the figures, the insulating track is not complete insofar as it is interrupted over an angular sector 33 in which the track

contact 28.

  The lower free end 25 of the second contact blade 24 is permanently in contact by elastic support with the radially intermediate annular portion of the

  contact track 28 which extends in a continuous ring.

  The third contact blade 26, which constitutes the stop blade of the rotary switch, comprises an intermediate fold 32 substantially in length so that its free end section 34 extends in a vertical plane of orientation substantially tangential with respect to to axis A. The lower free end 36 of the stop contact blade is shaped with a rounded lower edge 38 which can cooperate in elastic support with the upper face of the B587 disc 12, and in particular by contact with the face upper 29 of the contact track 28, which extends in a horizontal plane perpendicular to the axis A. According to a known arrangement, the upper face of the disc 12 comprises a cam 40 formed in relief in the form of a strip of insulating material of radial thickness

substantially constant.

  The cam 40 extends along a determined angular sector and it is angularly delimited by a vertical edge io of free front end 42 and by a vertical edge

rear free end 44.

  The cam 40 is delimited radially inwards by an internal vertical lateral face 46 and by a face

lateral vertical exterior 48.

  The conformation of the cam 40 according to the invention is such that the radius of curvature of the inner lateral face 46 decreases progressively from its rear edge 44 to its

front edge 42.

  In accordance with the teachings of the invention, the conformation and the geometric arrangement of the blade 26 are such that when its lower free end 36 faces the cam 40, the blade 26 is flexed elastically and transversely relative to the plane in which extends the section 34 so as to be in elastic support, radially

  outwards, against the internal lateral face 46.

  On the contrary, when the contact blade 26 is in its angular position, relative to the disc 12, shown in FIGS. 4 and 5, the blade 26 is in its stable state of rest, that is to say that it does not is not flexed elastically according to the

transverse direction.

  By cons, whatever the angular position of the blade 26 relative to the disc 12, the conformation is such that B587 its lower end 38 is always in elastic abutment against the portion of the upper face of the disc 12 opposite

  from its lower end edge 38.

  The stable state of rest and the elastic deformations of the blade 26 result from the fact that its upper free end

  front is recessed like a beam in the holder

  contacts while its rear free contact end 36

  constitutes the free end of the flexing beam.

  According to a known arrangement, beyond the edge o of the front end 42 of the cam 40, the contact track 28 is interrupted to delimit an annular stop zone ZA made of insulating material with which the rear end of 36 cooperates, 38 of the contact blade 26 when the disc 12 is in

  its angular stop position illustrated in FIG. 4.

  As can be seen in particular in FIG. 3, the insulating track constituting the stop zone ZA extends angularly, from front to rear, beyond the edge 42 to form a neutral zone ZN which extends radially to the outside of the cam 40, that is to say along its face

lateral 48.

  As can also be seen in FIGS. 1 to 5, the neutral zone ZN which extends the stop zone ZA is shaped into a ramp, that is to say that the dimension or altitude of its free upper face gradually increases from the front edge 42

  from cam 40 to its rear edge 44.

  Starting from Figure 2, the operation of the disc

  12 in association with the contact blade 26 is as follows.

  The disc 12 normally rotates in the first direction S1 indicated in FIG. 2, that is to say in the counterclockwise direction considering the figures which corresponds to the drive in

rotation of the electric motor.

  B587 During this course, the rear free end 36, 38 is in contact with the upper face 29 of the contact track 28 and progressively in elastic support radially outwards with the internal lateral face 46 of the cam 40 which is spiral shaped. As soon as the rear free end 36 exceeds the front free end edge 42 of the cam 40, that is to say also the end of the contact track, the blade 26, 34 covers, under the effect of its stress elastic, are free state of rest, that is to say that the rear free end 36, 38 suddenly moves radially outward to come to occupy its position shown in Figure 4 in which it is in vertical support down with the stop zone ZA. The electric motor is switched off automatically and the contact blade 26

  i is no longer flexed elastically in the transverse direction.

  If we try to force the rotation of the disc 12,

  for example by acting manually on a wiper arm

  glass, in the opposite direction S2 (see FIG. 4), the rear free end 36 of the contact blade 26 which then lies opposite the neutral zone ZN shaped as a ramp, traverses it

  angularly from front to back, gradually rising.

  As this neutral zone ZN is the insulating material, this rotation in the S2 direction does not cause the motor to restart, thus avoiding the so-called bell phenomenon (see

figure 5).

  In this neutral position of the contact blade 26, illustrated in FIGS. 4 and 5, it is not elastically bent in the transverse direction and its free end 36 faces the external lateral face 48 of the cam 40, but

  it is not in elastic abutment against the latter.

  B587 The bell phenomenon is thus avoided without causing additional transverse elastic stress

blade 26.

  The variant of this embodiment illustrated in FIGS. 6 to 9 will now be described. In these figures elements and components which are identical, similar or analogous to those described above are

  designated by the same reference numbers.

  As can be seen in these figures, the neutral zone ZN is of height, or altitude, substantially constant and it is shifted vertically upwards relative to the plane

  horizontal of the upper face 29 of the contact track 28.

  In the vicinity of the front free end edge 42 of the cam 40, there is provided a lug 50 formed in relief above the

  plane of the upper face 29 of the contact track 28.

  The vertical rear face 52 of radial orientation, of the lug 50 constitutes a stop with which is capable of cooperating the lower edge of the rounded rear free end 38

contact blade 26.

  The cooperation of the edge 38 with the abutment face 52 causes a cam effect which lifts vertically upwards the rear free end 36 of the contact blade 26 which thus automatically rises to the plane of the face

  upper annular of the neutral zone ZN.

  Thus, when the rotation of the disc 12 in the direction S1 causes the front free end edge 42 and the lug 50 to be crossed, the rear free end 36 of the contact blade 26 leaves on the one hand the track of contact 28 but remains in contact with the rear transverse face 52 which can also

be conductive.

  As soon as the rotation is sufficient for the free end 36 to arrive at the top of the lug 50, under the effect of its B587 It elastic transverse stress, the blade 26 automatically causes the release radially outward from its end free rear 36 so that she comes on the

stop zone ZA.

  As before, if the disc 12 is rotated manually in the opposite direction S2, the free end 36 of

  the contact blade 26 will travel through the neutral zone ZN.

  If its previous travel over zone ZA, taking account of the stopping time and braking of the electric motor, has moved it angularly forwards from zone ZN, the free end 36 can then go back up on the latter by through a

  ZR insulating section in the form of a ramp (see Figure 7).

  As a variant, not shown, and in order not to bend the blade during its travel along S2, the lateral face

  outer 48 is made of flexible or deformable elastic material

  ment and the blade deforms it instead of extending opposite.

B587

Claims (11)

  1. Rotary switch (10) for stopping in the position of an electric motor, in particular for stopping in the parking position of an engine for the alternating sweep drive of a motor vehicle wiper mechanism , of the type which comprises: - a disc (12) driven in rotation by the motor, an annular upper face of which comprises at least one electrical contact track (28, 29) made of conductive material in the form of an annular sector and which is delimited angularly by a front edge of end of track beyond which extends angularly forward an annular stop zone (ZA) non-conductive of electricity which extends angularly towards the rear, parallel to the annular track contact (28, 29), by a neutral annular zone (ZN) nonconductive; - And a fixed contact blade (26, 36, 38) which extends generally in a tangential direction, one front end of which is fixed and the other rear free end (36, 38) of which is in particular capable of cooperating, in function of the angular position of the disc, either with the annular conductive contact track (28, 29), or with the stop zone (ZA) and of the type in which the disc (12) has on its upper face a cam ( 40) which extends angularly from back to front to said front edge (42) of the end of the contact track, which radially separates the annular contact track (28, 29) from the neutral annular zone (ZN), which is delimited radially by an internal lateral face (44) and by an external lateral face, and with which the rear free end (36, 38) of the contact blade (26) cooperates, forming a cam follower element, for causing or not elastic deformation of the contact blade (26) so as to cause it to flex B587 transversely in a plane generally parallel to the upper face of the disc so that its rear free end moves radially to cooperate with the contact track (28, 29) when the disc rotates in a first direction (Sl), from back to before, and to cooperate with the neutral zone (ZN) when the disc (12) rotates in a second opposite direction (S2); characterized in that the blade (36) cooperates with a lateral face (46) of the cam (40) when the disc (12) rotates in the first direction (SI), being bent transversely as long as its free end (36) has not crossed, from back to front, the front end edge (42) of the contact track, and in that the contact blade (26) is in its free state not bent transversely when of a share its free rear end cooperates with the stop zone (ZA) and when, on the other   apart, it cooperates with the neutral zone (ZN).   2. Switch according to claim 1, characterized in that the stop zone (ZA) is substantially coplanar with the contact track (28, 29).   3. Switch according to any one of the claims.   previous cations, characterized in that the neutral zone (ZN) is shaped like a ramp.   4. Switch according to claim 3, characterized in that the height of the ramp (ZR) gradually increases back and forth.   5. Electric switch according to one of the claims   cations 1 or 2, characterized in that the neutral annular zone (ZN) extends in a plane which is offset vertically upward relative to the plane of the contact track (28, 29), and in that the edge front (42) of the end of the contact track is formed into a stop (50, 52) with which the rear free end (36, 38) of the contact blade (26) cooperates, * B587   rounded conformation, to cause a vertical displacement upwards of this free end at a height   corresponding to the altitude of the neutral annular zone (ZN).   6. Electric switch according to any one of   previous claims, characterized in that said face   side of the cam is its inner side face (46), and in that the radius of this inner side face gradually decreases from its rear free end edge (44)   to its front free end edge (42).   7. Electric switch according to any one of   previous claims, characterized in that the cam   (40) is of substantially constant radial thickness over all its length.   8. Switch according to any one of the claims.   previous cations, characterized in that the annular stop zone (ZA) and the neutral annular zone (ZN) are two   sections of tracks made of electrically insulating material.   9. Switch according to any one of the claims   previous cations, characterized in that the contact blade   (26) extends substantially in a vertical plane.   10. Switch according to any one of the resellers   previous indications, characterized in that the disc body   (12) is a molded piece of electrically insulating material.   11. Switch according to any one of the claims.   previous cations, characterized in that the periphery of the   disc (12) is shaped into a toothed pinion (18).