FR2818792A3 - Electrical switch for brake lights includes self-adjusting mechanism with joint having elastically deformable teeth - Google Patents

Abstract

The switch includes a switching slide (26) which is equipped with a control shaft (40) linked to the slide, via a joint (42) with elastically deformable teeth. The joint can be locked in position in order to achieve a required setting for the switch operating mechanism. The self-adjusting switch includes a switching slide (26) which is equipped with a control shaft (40) linked to the slide, via a joint (42) with elastically deformable teeth. The joint can be immobilised in its position on the control shaft (40) by rotation of a pressure element (43) with respect to the joint. The switch is fitted into an external box (5) which can be fastened to a support element (4) by a bayonet fitting (13). The pressure element (43) is mounted to rotate and slide axially with respect to the box and may be angularly locked on the support element (4). The slide (26) is mounted to slide axially and is fixed angularly with respect to the box.

Description

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 The present invention relates to a self-adjusting switch, particularly for controlling the brake lights of a motor vehicle.

 More particularly the present invention relates to a switch of the type comprising an outer casing capable of being coupled to a support element by means of a coupling movement comprising a first translational movement in a determined direction and a second movement of rotation about an axis parallel to said direction, an electrical switching device operable from a first to a second switching position in said direction and against the thrust of elastic means, a slide for actuating the switching device, the slide being coupled to the casing to slide relative to the casing itself, in said direction, a control rod parallel to said axis, an axial coupling joint of the rod to the slide, the joint being elastically deformable of a configuration d coupling to an axial uncoupling configuration between the rod and the slide and a member e pressure coupled to the slide to rotate, with the slide itself, around said axis from and to an operational position for blocking the seal in said coupling configuration.

 A self-adjusting switch of the aforementioned type is described in the international application published under WO. 98/25283 (EP-B-0941547).

 In this known switch, said pressure member is integral (in this case, integrally) with the outer casing and is arranged, relative to the slide and before coupling of the switch to the support element, in a rest position , wherein the pressure member allows said seal to deform elastically to ensure its uncoupling configuration. In this way, by carrying out said first movement of axial translation of the mounting of the casing on the support element, it is possible to put first a free end of the control rod in contact with a support, for example the pedal. brake, of which

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 we want to record a displacement and continue, therefore, until the end of the axial displacement, itself, so as to apply an axial compression thrust on the control rod and determine an elastic deformation of the seal and, consequently, a axial sliding regulation of the control rod relative to the slide.

 In the aforementioned known switch, the slide is coupled to the outer casing so as to be able to rotate relative to the outer casing around said axis, while it is angularly blocked with respect to the support element via of said first axial translation movement.

 What has just been described confers on the aforementioned known switch, the essential characteristic of executing, by means of the first axial translation movement, the self-adaptation of the axial position of the control rod relative to the slide. and the angular blocking of the slide itself on the support element and, with respect to the second successive rotational movement, the blocking of the external envelope on the support element and, at the same time, the angular displacement of the pressure member with respect to the slide for carrying the pressure member itself in its operational position for blocking said seal.

 In other words, said mounting movements determine either the blocking of the outer casing on the support element, or the axial blocking of the control rod on the slide.

déformant le joint de liaison avec le coulisseau lui-même. Une telle déformation est immédiatement bloquée par l'organe de pression, mais In the known switch described above, such an important result is not obtained without disadvantage and this is the case when such a switch is actuated, in use, for example following the actuation of the brake pedal with which the switch itself is associated. Indeed, as already said, the control rod, when it is stressed axially during use, tends to move relative to the slide in

deforming the connecting joint with the slide itself. Such deformation is immediately blocked by the pressure member, but

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 obviously determines the creation, between the pressure member itself and the seal, of tensions which tend to axially block the slide with respect to the pressure member and, therefore, with respect to the external envelope, with as a consequence the break of the control rod and the total damage of the switch.

 The object of the present invention is to provide a self-adjusting switch of the type described above, which does not have such drawbacks.

 According to the present invention, there is provided a self-adapting switch particularly for controlling the brake lights of a motor vehicle, the switch comprising an outer casing capable of being 'coupled to a support element by means of a movement d coupling comprising a first translational movement in a determined direction and a second rotational movement about an axis parallel to said direction, an electrical switching device actuable from first to a second switching position in said direction and against the pushing of a first elastic means, an actuating slide of said switching device, the slide being coupled to said casing to slide, relative to the casing itself, in said direction, a control rod parallel to said axis, an axial coupling seal of said rod to said slide, this seal being elastically deformable in a con figuration of coupling to an axial uncoupling configuration between the rod and the slide, and a pressure member coupled to rotate, relative to the slide itself, around said axis from and towards an operational position for blocking said seal in said configuration coupling, characterized in that said pressure member is rotatable and axially sliding in said direction relative to said outer casing, first and second locking means being provided for angularly blocking, in operation, said pressure member with respect to said element of

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 support and, respectively, for angularly blocking said slide with respect to said envelope.

 In the switch defined above, there is always the risk that, with an axial displacement of the control rod, corresponds to a blocking of the pressure member on the actuating slide of the switching device; in this case, however, unlike the known switch described above, the pressure member is no longer integral with the external envelope but can slide axially, jointly with the control rod and with said slide, relative to the outer envelope in which it is guided, which eliminates any possibility of breakage of the control rod itself.

 The invention will now be described with reference to the accompanying drawings which illustrate certain nonlimiting examples of embodiment of the invention.

 Figure 1 is a three-quarter perspective view from above of a preferred embodiment of the switch according to the present invention and of a support element.

 Figure 2 illustrates the switch according to Figure 1 in axial section.

 Figure 3 is a section along the oil-oil line of Figure 2 illustrating the switch of Figure 1 in a different operational position.

 Figures 4 and 5 show two sections along the same line IVIV of Figure 3 illustrating the switch of Figures 1 to 3 in different operational configurations.

 FIG. 6 is a section on line VI-VI of FIG. 3.

 With reference to FIG. 1, the reference 1 indicates the assembly of a self-adjusting switch for controlling the lights (not shown) of a motor vehicle stop (not shown).

 The switch 1 is capable of being mounted through a circular hole provided with diametrically opposite notches 3 and produced through a support element 4 rigidly connected to the bodywork (not shown) of said motor vehicle.

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 The switch 1 comprises an external casing or housing 5 comprising a body 6 having a side wall 7 substantially cylindrical and closed at one end by a bottom wall 8 orthogonal to an axis 9 of the side wall 7 and provided, in a part separated of the side wall 7, of a tubular appendage 10 centered on the axis 9 of the body 6 and communicating with the interior of the latter by an axial bore 11.

 The appendix 10 is able to be threaded into the hole 2 by axial displacement of the envelope or case 5 in a direction 12 parallel to the axis 9 and it is provided with projecting lateral parts capable of passing through the notches 3 for mate with the support element 4, by rotation of the casing 5 around the axis 9, forming, with the support element 4, a bayonet joint 13.

 At its end opposite to that carrying the appendix 10, the first hollow body 6 is closed by a second hollow body 14 turning its concavity towards the inside of the hollow body 6 and comprising a side wall 15 inserted inside the wall lateral 7 and snap-connected to the latter, by means of elastic teeth 16, the second hollow body 14 being closed by a bottom wall 17 which is parallel to the bottom wall 8 of the first hollow body 6 and supports a switching device 18.

disposés en face des contacts 20 dans la direction 12 et à une distance déterminée desdits contacts 20 vers la paroi du fond 8. Le dispositif de commutation 18 comprend en outre une plaque de commutation 24 réalisée dans un matériau métallique, parallèle à la paroi de fond 17 et qui peut se As shown in FIG. 2, the switching device 18 comprises four metal plugs which pass through the bottom wall 17 parallel to the axis 9, respectively two central plugs 19 fitted, inwards, with front contacts 20 and constituting the plugs of a service circuit (not shown) and two lateral plugs 21 and 22 folded in L, which constitute the plugs of a circuit (not shown) for supplying the brake lights. The plugs 21 and 22 are fitted with internal contacts 23 which are

arranged opposite the contacts 20 in the direction 12 and at a determined distance from the said contacts 20 towards the bottom wall 8. The switching device 18 further comprises a switching plate 24 made of a metallic material, parallel to the bottom wall 17 and who can

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 move in the direction 12, inside the casing of the housing 5, in the space between the contacts 20 on the one hand and the contacts 23 on the other hand.

extrémité en regard de la paroi de fond 8 du boîtier 5, par un fond 28 transversal à l'axe 9 et présentant une bride externe pourvue de deux appendices radiaux 28a diamétralement opposés. La douille 27 est accouplée à l'enveloppe 5 par l'intermédiaire d'un dispositif de blocage angulaire 29 comprenant, comme le montre la figure 6, une pluralité de nervures 30 parallèles à l'axe et s'étendant vers l'extérieur en saillie par rapport à la face externe de la douille 27 et un même nombre de rainures axiales 31 ménagées respectivement sur la face interne de la paroi latérale 15 du corps creux 14 et s'engageant de manière axialement coulissante, chacune dans une nervure 30 correspondante de la douille 27. Springs 25 (only one of which has been shown in FIG. 2) are interposed between the plate 24 and the bottom wall 17 in order to keep the plate 24 normally in contact with the contacts 23. Inside the envelope 5 is mounted axially sliding, in direction 12, a slide 26 for actuating the switching device 18. The slide 26 comprises a socket 27, centered on the axis 9 and closed at its

opposite end of the bottom wall 8 of the housing 5, by a bottom 28 transverse to the axis 9 and having an external flange provided with two diametrically opposite radial appendages 28a. The sleeve 27 is coupled to the casing 5 by means of an angular locking device 29 comprising, as shown in FIG. 6, a plurality of ribs 30 parallel to the axis and extending outwards in projecting from the external face of the sleeve 27 and the same number of axial grooves 31 formed respectively on the internal face of the side wall 15 of the hollow body 14 and engaging in an axially sliding manner, each in a corresponding rib 30 of the socket 27.

correspondante 34 ménagée sur la paroi de la douille 27. De plus, l'embout 33 peut coulisser axialement le long de la douille 27, entre une position de repos de fin de course représentée sur la figure 3 et une position de travail représentée sur la figure 2, contre l'action d'un ressort 35 bien plus rigide The slide 26 further comprises an end piece 32 which is normally in contact with the switching plate 24 and is inserted inside the open end of the socket 27 facing the bottom wall 17 of the second hollow body 14 The end piece 32 is hooked to the tubular element 27 by means of the elastically deformable radial teeth 33, which engage by snap-fastening, each inside an axial lumen

corresponding 34 formed on the wall of the socket 27. In addition, the end piece 33 can slide axially along the socket 27, between a rest position at the end of the stroke shown in FIG. 3 and a working position shown in the Figure 2, against the action of a much more rigid spring 35

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que les ressorts 25 de poussée de la plaque 24, ce ressort 35 étant interposé entre l'embout 32 et la paroi de fond 28 du coulisseau 26.

as the springs 25 for pushing the plate 24, this spring 35 being interposed between the end piece 32 and the bottom wall 28 of the slide 26.

A tubular sleeve 36 centered on the axis 9 extends axially from the bottom wall 28 towards the bottom wall 8 of the housing 5, and is crossed, like the bottom wall 28, by a hole 37 centered on the axis 9. At the free end of the sleeve 36 extend axially two appendages 38 elastically deformable in the transverse direction, on which are arranged respectively, as shown in Figures 4 and 5, two internal teeth 39, diametrically opposite of on either side of the hole 37 and forming a circular sector centered on the axis 9 and having an apex angle of at most 90.

 Through the holes 11 of the appendix 10 and 37 of the socket 36, passes a control rod 40 externally provided with an external toothing 41 subdivided into two sectors of opening substantially equal to that of the appendages 38 of the socket 36 and cooperating with the internal teeth 39 of the latter to define a tooth seal 42 making it possible to axially fix the rod 40 relative to the slide 26 when the external teeth 41 and internal 39 are engaged with each other, leaving, however, the rod 40 a certain freedom of axial movement relative to the slide 26 when a thrust applied to the external toothing 41 and transmitted to the internal toothing 39 of the appendages 38, makes it possible to separate the latter elastically towards the outside.

 The tooth seal 42 can be immobilized, on the one hand in its coupling position, that is to say of axial fixing of the rod 40 with the slide 26, by means of a pressure member 43 of tubular shape, centered on the axis 9 and, on the other hand, angularly relative to the support element 4 by means of a locking device 44.

 The pressure member 43 is wedged on the sleeve 36 and the appendages 38 thereof and is internally limited by a cylindrical face 45 capable of cooperating with the appendages 38 to maintain the internal teeth 39

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 corresponding in engagement with the external toothing 41 of the rod 40. The cylindrical face 45 has, for each appendage 38, an axial recess 46 in which the appendage 38 can be accommodated and whose depth is at least equal to the thickness of the internal toothing 39 of the corresponding appendage 38, so that, when each recess 46 is facing the appendage of a correspondent, said appendages 38 can bend under the thrust of the teeth of the external toothing 41, in a uncoupling position of the two teeth 41, respectively of the rod 40 and 39 of the appendages 38.

 The locking device 44 comprises a guide 47 comprising itself a tubular body 48 wedged on the pressure member 43 and interposed between said pressure member 43 and the side wall 7 of the hollow body 6.

 The tubular body 48 is threaded into the hollow body 6 while being able to rotate about the axis 9 and it is locked axially with respect to the envelope of the hollow body 14. It is provided with two axial appendages 49 which extend to the exterior of the casing 5 passing through corresponding openings in the bottom wall 8 and can engage in respective notches 3 for angularly locking the guide 47 relative to the support element 4. The tubular body 48 defines a cylindrical seat for the pressure element 43 and is provided, on its internal face, with axial ribs 50 which engage in sliding manner inside corresponding axial grooves 51 formed on the external face of the member pressure 43.

 The body 48 is further provided at its end facing the bottom wall 17 of the hollow body 14, with two internal radial teeth 52, diametrically opposed, which are spaced from each other by a distance less than the diameter of the bottom wall 28 of the slide 26, in correspondence with the appendages 28a and can cooperate, as will be better explained below, with said appendages 28a of the wall in order to block the axial sliding of the slide 26 along the casing 5

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 when the body 48 is placed in a determined initial angular position, facing the slide 26.

 FIG. 4 shows the relative angular positions of the control rod 40, the appendages 38 and the pressure member 43 around the axis 9, during the mounting of the control rod 40 through the hole 37, each sector of the external toothing 41 of the control rod 40 being opposite a corresponding appendage 38, which is itself located opposite a corresponding recess 46.

 In addition, the appendages 28a of the bottom 28 of the slide 26 are aligned with the corresponding teeth 52 of the tubular body 48.

 Firstly, the control rod 40 is partially introduced through the hole 37 by applying a relatively small axial thrust on the rod 40 allowing only an outward bending of the appendages 38 placed opposite the corresponding recesses 46.

This operation being carried out, the switch 1 is mounted on the support element 4 by a first movement of axial translation in the direction 12, followed by a second movement of rotation around the axis 12.

During translation in direction 12, the appendix 10 progressively penetrates into the hole 2 of the support element 4, and the free end of the control rod 40 comes into contact with a reference member (not shown), for example the brake pedal arm. The translation continues in direction 12, and the control rod 40 bears on said reference member (not shown) determining a first axial movement of the slide 26 towards the bottom wall 17 with crushing of the springs 25. This movement continues until 'that the appendages 28a come into contact with the corresponding teeth 52. Continuing further the translation in direction 12, the axial pressure applied to the control rod 40 determines the outward deformation of the appendages 38 which are housed in the corresponding housings 46, with as a consequence the uncoupling of the

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 internal 39 and external 41 teeth, the rod 40 being able to slide axially with respect to the slide 26.

 At the end of the translation in direction 12, the control rod 40 has completely axially self-adjusted (the springs 25 being compressed) relative to the slide 26 and the appendages 49 have engaged in the corresponding housings 3 so angularly wedging the tubular body 48 and, therefore, the pressure member 43 relative to the support element 4.

 At this time, the mounting of the switch 1 is completed on the support element 4 by applying to the casing 5 a rotational movement of approximately 900 around the axis 9. This movement determines the closing of the seal at bayonet 13 and the tooth seal 42, with simultaneous locking of the casing 5 on the support element 4 and of the control rod 40 on the slider 26. In fact, the slider 26 is made angularly integral with the casing 5 of the blocking device 29, while the pressure member 43 is made angularly integral with the support element 4 by means of the blocking device 44. Therefore, a rotation of 900 of the casing 5 by relative to the support element 4 corresponds to an equivalent rotation relative to the pressure member 43, appendages 38 which, at the end of the rotation, are in the position indicated in FIG. 5, for which the pressure element 43 prohibits any elastic deviation towards the e outside of appendages 38.

laissant au coulisseau 26 une complètement liberté de déplacement dans le sens axial par rapport à l'enveloppe externe 5. A ce moment, l'organe de pression 43 se trouve pratiquement accouplé, dans le sens axial, avec le coulisseau 26 mais celui-ci reste libre de se déplacer axialement grâce à l'accouplement axialement coulissant de l'organe 43 avec le guide 47. In addition, a rotation of 900 of the casing 5 relative to the support element 4 described above determines an angular offset of 900 of the appendages 28a of the bottom 28 relative to the corresponding teeth 52 in

leaving the slide 26 a complete freedom of movement in the axial direction relative to the outer casing 5. At this time, the pressure member 43 is practically coupled, in the axial direction, with the slide 26 but the latter remains free to move axially by virtue of the axially sliding coupling of the member 43 with the guide 47.

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 When the brake pedal (not shown) is at rest, the switch 1 is in the configuration illustrated in FIG. 2, while when the brake pedal is actuated, the slide 26 and the control rod 40 come under the thrust of the springs 25, in the position illustrated in FIG. 3, in which the switching plate 24 interconnects the contacts 21 and 22 by closing the circuit (not shown) of the stop lights.

 Regarding the switch 1 described, it should be noted that, in the normal course of operation, the spring 35 is slightly compressed and develops the dual function of exerting, via the end piece 32, a pressure on the switching plate 24 to ensure good electrical contact, and to avoid a break in the control rod 40, by absorbing a possible overtravel of the end piece 32. It is also possible to use special mechanical anti-theft devices, such application determining the lifting of the brake pedal above its normal rest position.

 The reference signs inserted after the technical characteristics mentioned in the claims have the sole purpose of facilitating the understanding of the latter and in no way limit their scope.

Claims (11)

 1. Self-adapting switch, particularly for controlling the brake lights of a motor vehicle, the switch 1 comprising an outer casing or housing (5) capable of being coupled with a support element (4) by a movement d coupling comprising a first translational movement in a determined direction (12) and a second rotational movement around an axis (9) parallel to said direction (12), an electrical switching device (18) movable between a first and a second switching position in said direction (12) and against the thrust (2) of a first elastic means (25), an actuating slide (26) of said switching device (18), mounted to slide axially in said housing (5) in said direction (12), a control rod (40) parallel to said axis (9), an axial coupling seal (42) from said rod (40) to said slide (26), the seal (42) being elastically deformable of a configuratio n coupling to an axial uncoupling configuration between the rod (40) and the slide (26) and a pressure member (43) connected to said slide (26) and rotatably mounted, relative to the latter around said axis ( 9) from and to an operational position for blocking said seal (42) in said coupling configuration, characterized in that said pressure member (43) is rotatably mounted and axially sliding in said direction (12) relative to said external housing (5), the first and second locking means (44, 29) being provided for angularly blocking, in use, said pressure member (43) relative to said support element (4) and respectively, for angularly blocking said slide ( 26) relative to said housing (5).  2. Switch according to claim 1 wherein said first locking means (44) comprise a guide (47) angularly lockable on said support element (4) by means of said first movement and connected to said housing (5) so as to rotate, relative to the latter, about said axis (9), said pressure member (43) being connected to said guide (47) in a fixed angular manner with the possibility of axial sliding in said direction (12).  3. Switch according to claim 1 or 2 wherein said outer housing (5) is a substantially cylindrical housing coaxial with said axis (9). <Desc / Clms Page number 13>  4. Switch according to one of the preceding claims wherein said support member (4) has a hole (2), and said outer housing (5) comprises an end portion (10) capable of being inserted into said hole (2 ) during said first movement and immobilized on the support element (4) by means of a bayonet seal (13).  5. Switch according to one of the preceding claims, characterized in that said slide (26) comprises a tubular element (27) coaxial with said axis (9) and engaged axially sliding on said rod (40), said seal (42 ) being a tooth seal comprising at least one elastically deformable appendage (38) extending axially from said tubular element (25) and comprising an internal toothing (39) and an external toothing

 (41) arranged along said control rod (40), said pressure member (43) being capable of applying to said appendage (38) a force transverse to said axis (9) to hold said internal toothing (39) in engagement with said external toothing (41).  6. Switch according to claim 5 wherein said pressure member (43) is coaxial with said axis (9) and is internally limited by a cylindrical surface (45) cooperating with said appendage (38) to maintain said internal toothing (39) in engagement with said external toothing (41), said cylindrical surface (45) having at least one recess (46) of depth at least equal to that of the internal toothing (39), and in which is housed said appendage (38) , in order to allow said appendage (38) to be placed in said axial uncoupling configuration.  7. Switch according to one of claims 2 to 6 wherein said guide (47) comprises a tubular body (48) centered on the axis (9) of the housing (5) and connected to the latter in a manner allowing a rotation of said external housing (5) about said axis (9), said first locking means (42) further comprising at least one appendage (49) projecting radially from said tubular body (48) and able to engage frontally in corresponding housings (3) produced in said support element (4).  8. Switch according to claims 6 to 7 wherein said tubular body (48) defines a cylindrical seat for said pressure member (43) and is provided, inside, of axial ribs (50) slidingly engaging in corresponding axial grooves (51) formed on an external face of said pressure member (43). <Desc / Clms Page number 14>  9. Switch according to one of claims 5 to 8 wherein said slide (26) comprises a tip (32) coaxial with said axis (9), cooperating with said switching device (18) and mounted to slide axially on said tubular element ( 27) from a rest position and against the action of a second elastic means (35).

10. Switch according to claim 9 wherein said switching device (18) comprises a conductive switching plate (24), transverse to said axis (9) and movable in said direction (12), under the thrust of said slide (26) and against the thrust of said first elastic means (25), between a rest position in contact with at least one first contact (22) and a second position in contact with at least one second contact (19).  11. Switch according to claim 10 wherein the first elastic means (25) have a lower rigidity than those of said second elastic means (35).