FR2787915A1 - Self-adjusting electric contact switch for detecting opening of motor vehicle doors has pushrod sliding in body and serrated surface holding body at determined position - Google Patents

Abstract

The switch has a pushrod (52) sliding in a body (54), with an internal spring (84) acting outward. The body fits into a base (56) which is mounted on the door, and can be pushed into the base to different depths. A serrated surface (102) in the base holds the body at the deepest position it reaches when it is pressed inward.

Description

SELF-ADJUSTABLE ELECTRIC SWITCH

IN POSITION

  The invention relates to an electric switch intended to be actuated by a mobile control member. More specifically, the invention discloses an automatic adjustment mechanism for the position of the switch relative to the movable control member in a position.

abutment against a fixed element.

  Electric switches ensure the opening or closing of electrical circuits. Its applications being very diverse, the design of

  the switch will, in some cases, be linked to its application.

  In the automotive field, switches comprising a push-button are used to detect the opening of vehicle doors and activate the interior lighting of the vehicle. In certain types of commercial vehicles, a switch is attached to each of the two sides of the dashboard to detect the closing of the respective right and left front doors. The distance between the door of the vehicle in its closed position, and the body of the door switch can vary, on the one hand, from one vehicle to another, by the manufacturing and mounting dispersions of the dashboard but on the other hand, over time, by the appearance of clearances due to wear and deformation of the vehicle body. These distances can also be different from one vehicle model to another by their

design.

  A switch comprising a push-button having a sufficiently long stroke makes it possible to mitigate to a certain extent these

  variations in distances between the closed door and the door switch.

  Figure la shows such an electrical switch 10 of the state of

Art.

  The switch 10 comprises a pusher 12 sliding in a body 14, along an axis of translation XX '. The switch comprises an electrical contact 16 which can be opened or closed by the action of the pusher 12. The electrical contact 16 essentially comprises a fixed blade 18 and a blade

  mobile 20 each equipped with electrical contact pads 22, 24.

  The movable blade 20 is held on the one hand, on the side of a central part of the blade, by a first end of a cylindrical spring 26, the second end of the spring being fixed on the body 14 of the switch, and on the other hand on the side of the second end of the movable blade 20 by one of the two branches of a tilting blade 28 in the shape of a V, the end of the other branch of the V resting on a part

  rigid 30 secured to the body 14 of the switch.

  The tilting blade 28 comprises on the side of the other branch

  of the V, near the tip of the V, a semi-recess 32

  o10 circular coming to rest on the pusher.

  The pusher 12 has an upper part 34 of semi-shaped

  circular projecting outside the body of the switch and having a flat 36 parallel to the axis of translation XX 'and at a distance d from this axis. The upper part of the pusher is connected to a lower part 38 of the pusher of circular shape, situated inside the body of the switch, of length La much less than the total length Lb of the pusher. Figure 1b

  shows a sectional view along AA 'of the pusher 12.

  At rest, (Figure la) the pusher 12 is in the pulled position, pushed by a return spring 39. The recess 32 of the tilting blade 28 is supported on the circular surface located at the bottom of the pusher and at the distance D of the translation axis XX 'which holds, by means of the spring 26, the first end of the movable blade against the first end of the fixed blade by means of the studs 22 and 24. The contact

electric 16 is closed.

  FIG. 1c shows the switch 10 when the pusher is depressed during its action by a force F applied substantially according to

the translation axis XX '.

  A short stroke of the pusher (less than the length La of the circular lower part of the pusher), actuated by force F, moves the contact point of the recess 32 on the pusher, towards the flat 36, bringing the recess 32 closer to the distance d of axis XX '. The displacement of the tilting blade 28 pushed by the movable blade 20 itself pulled by the spring 26, causes the opening of the electrical contact 16. The electrical contact 16 will remain in this position throughout the movement of the pusher inwards of the switch body. This movement may take place over a predetermined length, at most, until the lower part of the pusher comes into contact with an abutment surface 40 of the body of the switch. This type of long-stroke switch of the prior art has drawbacks. Indeed, the stroke of the pusher is no longer sufficient to allow its use in vehicles of different types, having, from one vehicle to another, significant variations in distance between the vehicle door l0 and the light switch. A further lengthening of the stroke of the pusher and consequently of the length of the pusher would lead to a fragile pusher and to a bulky switch. A very long pusher which is fully extended when the vehicle door is

  open, is vulnerable and can be easily damaged.

  Another drawback of the pusher of FIG. 1a results from the appearance of the particles torn off by the friction of the recess 32 on the plate 36 of the pusher 12. These particles foul the electrical contact 16, reducing the reliability of the switch, and particularly in use with low operating electrical voltages,

  commonly used in motor vehicles.

  To overcome these drawbacks, the invention proposes an electric switch comprising a sliding push-button, along an axis of translation XX ', in a body held in a base, the push-button being able to pass from a position pulled at rest to a position pressed in at work. to actuate an electrical switch, the pusher being returned to the rest position by a return spring, characterized in that the body can be pressed more or less deeply into the base under the action of a force applied to the body along the axis of translation, and in that the switch comprises means for holding the body in the base in a selected depressed position, with a holding force greater than that

spring.

  In the switch according to the invention, the length of insertion of the body into the base makes it possible to compensate for significant variations in the distance between the control member actuating the pusher and the switch, without modifying the stroke of the pusher . This has the advantage of making it possible to use standard electrical contactors, produced in large series at low cost and more reliable. These standard contactors having a much shorter push stroke than

  that which would be necessary with a switch of the prior art.

  In an embodiment of the switch according to the invention, the stroke

  body penetration is much greater than the stroke of the pusher.

  The contactor can be a microswitch having a push button with a stroke less than that of the push button of the switch, a spring

  actuator being placed between the switch pushbutton and the button-

microswitch button.

  The resistance of the body to its insertion into the switch base by the action of a force applied to the body, must be greater than the force necessary for the compression of the return spring. Indeed, the insertion of the body into the base must be carried out only by the action of the movable control member on the body and not the force exerted by the return spring, during the action of the pusher by the organ of

  control, sliding the pusher into the body.

  The means for holding the body in the base at a position

  can be achieved in a variety of ways.

  In a first embodiment of the holding means, an external surface of the body is in close contact with a corresponding surface of the base, the holding being ensured by a force of

friction between these surfaces.

  In a second embodiment, a surface of the body is provided with ridges and a surface of the base is provided with corresponding ridges which fit into the ridges of the body. The maintenance being carried out by the

  resistance to the passage of streaks of the body on the streaks of the base.

  The invention also relates to a method of implementing a switch for detecting the abutment position of a movable control member against a fixed element, comprising the use of a switch having a push button sliding in a body and recalled by a return spring to a rest position, the body being inserted in a base carried by the fixed element, and being able to assume positions more or less sunk into the base by force-pushing in translation, the body being held in this position by a holding force greater than that of the return spring, the implementation consisting of initially inserting the body into the base in a slightly depressed position, then actuating the control member to its stop position in order to depress the body to a position that is automatically adjusted in depth. In an exemplary implementation of this method, the control member is a door, the fixed element is a door frame, the switch is a switch for detecting the open or closed state of the door, and the depression of the switch body is adjusted automatically by the first closing of the door, when the latter comes into contact with

its frame.

  This method finds a particularly advantageous use in the detection of the closing of the doors of motor cars, due to the fact, as described above, of the significant variation in the

  distance between door and switch.

  The invention will be better understood with the aid of exemplary embodiments of a switch according to the invention with reference to the appended drawings, in which: - Figures la and lb already described, represent views in

  section of a switch of the prior art.

  - Figures 2a, 2b and 2c respectively represent two views

  in section and a top view of a switch according to the invention.

  - Figures 3a, 3b and 3c show the switch of Figure 2a

  actuated by a mobile control member.

  Figures 2a and 2b show sectional views, respectively from the front and from the side, of a switch 50 according to the invention. The

  Figure 2c shows a simplified top view of the same switch.

  The switch 50 comprises a pusher 52 sliding in a body 54, of rectangular section, held in a base 56 in the form of a tube of substantially the same rectangular section as the body. The pusher, in its displacement along a translation axis XX ', actuates a

  microswitch 58 secured to the body of the switch.

  The body 54 comprises, on the side of its end projecting from the base, a first circular cylindrical passage 60, coaxial with the axis of translation XX ', this first passage 60 extending towards the inside of the body by a second passage 62 , preferably coaxial to the first, of larger diameter, and opening into a recess 64 in which is

found the microswitch 58.

  A circular cylindrical upper part 66 of the pusher 52, sliding in the first passage 60 and protruding, in the pulled position, by a length Lp of the body 54 of the switch, is extended in the second passage 62 by a lower part 68 of shape larger cylindrical

  width than the upper part 66 of the pusher.

  The lower part of the pusher has two symmetrical lo walls 70, 72 on either side of the axis XX 'parallel to an internal cylindrical circular part 74 coaxial with this same axis XX and of

  substantially the same diameter as the upper part 66 of the pusher.

  The symmetrical walls 70, 72 are connected to the pusher 52 by a recess 76 comprising, on the side of the upper part 66 of the pusher, a bearing surface 78 and on the side of the lower part 68 of the

  push a push surface 80.

  The bearing surface 78 abuts against an abutment surface 82 of the body resulting from the intersection of the first 60 and the second 62 passage, by the thrust of a return spring 84 compressed between the surface of

  thrust 80 and microswitch 58 secured to the body of the switch.

  The microswitch 58 comprises a push button 86 located approximately in the axis of translation XX ′ under the internal part 74 of the push button 52. The push button is controlled by an actuating spring 88 compressed during the action of the push button 52 The stiffness of the actuating spring 88 is greater than that of an internal spring of

  reminder (not shown in the figure) of the microswitch.

  The internal part 74 of circular cylindrical shape, has a recess 90 of the same shape, coaxial with the axis XX 'of translation. The recess is closed at one of its two ends, the other end opening into

the second passage 62.

  The recess 90 comprises the actuating spring 88 of cylindrical shape resting on the one hand on the closed end of the recess and on the other hand on the push button 86 of the microswitch 58 Two external faces 92, 94 walls of the body of the switch, parallel to a plane passing through the axis XX 'of translation and through the middle of the symmetrical walls 70, 72 as well as the corresponding internal faces 96,

  98 of the walls of the base, respectively have grooves 100, 102.

  In a position for holding the body in the base, the bumps of the ridges 100 of the external faces 92, 94 of the body, penetrate into the hollows of the ridges 102 of the corresponding internal faces 96, 98 of the base. The base 56 comprises, on the outside of its rectangular section, on the one hand, a border 104 on the periphery of the rectangular opening situated on the side of the pusher, and on the other hand, two flexible blades 106, 108 on two lateral faces 110, 112 perpendicular to the internal faces 96, 98 comprising the ridges. A first edge 114, 116 of the flexible blades 106, 108 is fixed in a central part of the lateral faces 110, 112 of the base, a second edge 118, 120, parallel to the first edge and to the edge 104

  from the base, is slightly spaced from the side faces of the base.

  The flexible blades 106, 108 and the edge 104 lock the switch mounted on a support plate 122. For this purpose, the switch is slid into a rectangular orifice 124 formed in the support plate 122, the orifice 124 leaving pass base 56 and its two

  flexible blades 106, 108 pressed against the lateral faces 110, 112.

  When the edge 104 is applied against the support plate 122, the flexible blades 106, 108 return to their initial position locking the switch by tightening the support plate 122 between the edge 104 and

  the second edges 118, 120 of the flexible blades 106, 108.

  We will subsequently describe the operation of the self-adjusting switch, in the case of a first contact between the unadjusted switch and a movable control member 126 whose stroke exceeds the stroke

maximum Lp of the pusher.

  Figures 3a, 3b and 3c show the switch 50 according to the invention mounted on the support plate 122. A stop 128 indirectly integral with the support plate 122 limits the travel of the movable control member 126 in its movement towards the plate support (fixed elements). The stop 128 is mechanically connected to the support plate 122 by different mechanical parts shown in FIGS. 3a, 3b and 3c by a dotted link 123. The mounting clearances of the link 123 as well as the variations in the dimensions of the mechanical parts of this connection mean that the position of the stop 128 relative to the support plate 122 may vary from one assembly to another. FIG. 3a shows the switch not adjusted, in an initial position, the body 54 of the switch leaving the base 56 of a certain maximum length Li, measured between the upper end of the body 56 and the support plate 122 The mobile control member 126 is not yet in contact with the push-button 52 of the switch (FIG. 3a) which is in the pulled position at rest. In the rest position, the pusher 52 is pushed back by the return spring 84 to its stop position, the surface

  l0 of support 78 of the pusher coming to butter against the abutment surface 82 of the body.

  The actuating spring 88 is just held in the recess 90 without compression, exerting no force on the push button 86 of the

  microswitch 58 which is in the rest position.

  In a first phase, the switch is actuated by the mobile control member 126, exerting on the pusher 52, along the axis XX 'of translation, a first force Fp sufficient to compress the springs of

  recall 84 and actuation 88 of the switch.

  The pusher 52 then moves towards the inside of the body 54 under the action of the first force Fp, compressing the return springs 84 and

  88, the latter applying increasing force to the button-

  push-button 86 of microswitch 58 until it switches to the working position. In this first phase, the mobile control member 126 will have moved the pusher by a length not exceeding its maximum stroke (length Lp of the pusher). FIG. 3b shows the pusher 52 of the switch in the depressed position at work without displacement of the body 54

in base 56.

  In a second phase, the mobile control member 126 continues its travel with a second force Fc sufficient to produce

  The insertion of the body 54 into the base 56 of the switch.

  The body is moved by the mobile control member 126 to a stop position 130 limiting its travel to a certain length Lc (see FIG. 3c), this length Lc not being able to exceed a maximum length Lx corresponding to the limit d sinking of the body in the switch base. This stop position 130 is determined by the stop 128 which can be located in any position between Lp (initial position of the body extended from its maximum length, in FIG. 3a)

  and Lx (limit of insertion of the body into the base).

  The movement of the body in the base by the second force Fc is effected by discontinuous friction due to the passage of the ridges 100 of the external faces 92, 94 of the body (see FIG. 2b), on the ridges 102 of the corresponding internal faces 96, 98 of the base with a slight deformation, by the flexibility of the faces, during the passage of the bumps of the striations of the body

  and the base, one on top of the other.

  Maintaining the position of the body in the base, when the movable member is no longer in contact with the body of the switch is obtained by the resistance of passage of the ridges of the external faces of the body on the ridges

  corresponding internal faces of the base.

  In a third phase (not shown in the figures), when the mobile control member 126 moves away from the switch, the pusher 52 returns to its initial position pulled at rest from the length Lp, pushed by the spring of reminder 84, the body remaining in its self-adjusting position in FIG. 3c. The actuating spring 88 expanding to its initial length when the pusher returns to its initial position no longer exerts sufficient force on the push button 86 of the microswitch, which switches

in the rest position.

  The mobile control member 126, upon its first contact with the stop 128, automatically adjusts the position of the body to the stop position 130. During subsequent commands to the switch by the mobile control member, only the pusher 52 will be moved around the body on its

maximum length Lp.

  A change in the position of the stop 128, or a modification of the stroke of the movable control member 126, leading to a stroke greater than the initial adjustment stroke Lc, would produce a new adjustment of the position of the body in the base by the thrust exerted on the body by the mobile control member 126, within the limit

  switch setting possibilities.

  On the contrary, a reduction in the initial stroke Lc can be easily compensated for by manually pulling the body of the base with a force which can be, depending on the shape of the ridges on the faces of the body and the base, or otherwise weaker than the force required

  when the body is pushed into the base by the mobile control member.

  For this purpose, the body comprises for example grooves 132 making it possible to easily extract the body from its base using a tool, up to its maximum extended position. In an automotive application, the movable control member 126 is a door, the support plate 122 and the movable stop 128 are the frame of the door (fixed element), the switch is a switch for detecting the open or closed state of the door. The insertion of the switch body into the base is automatically adjusted by the first

  closing of the door when it comes into contact with its frame.

  In the exemplary embodiment of the switch according to the invention of FIG. 2a, the means for holding the body in the base, in a selected depressed position, include grooves on the external faces of the body and the corresponding internal ones of the base. These means are not

  not limiting to those described in this embodiment.

  In another embodiment of these holding means, an external surface of the body is provided with teeth and a corresponding surface of the base is provided with notches, or the opposite. Teeth and notches having surfaces inclined with respect to the axis

of translation XX '.

  The choice of the inclination of the surfaces of the teeth relative to the axis of translation thus makes it possible to obtain different driving forces.

  or extracting the body from the switch base.

  For example, teeth and notches can be produced such that the surfaces on one side of the teeth and on the side of the notches, in contact during extraction of the body of the switch, are substantially perpendicular to the axis of translation, and that the surfaces on the other side of the same teeth and the same notches in contact during the insertion

  of the body, are more or less inclined relative to this same axis XX '.

  This configuration of the teeth and the notches leads to an extraction force much greater than the force of driving the body into the base, the resistance of passage of a tooth on a notch increasing with the angle of the surfaces relative to the direction of movement (axis of

translation XX ').

  On the contrary, in other embodiments of the holding means comprising teeth and notches, the inclinations of their surfaces in contact with respect to the axis of translation XX 'will be such that the forces necessary for the insertion of the body into the 'bases are greater than the extraction forces. In other variants of these holding means, an external surface of the body is provided with bosses and a corresponding surface of the base is provided with recesses, or the opposite. The body and the base of the switch can be manufactured in lo plastic material ensuring a certain flexibility of their walls and the passage of striations or teeth of the body over those of the base during a

  depression or extraction of the body in the base.

  The body can be produced in two assembled half-shells,

  enclosing the various elements of the switch.

  The switch according to the invention has the advantage of making it possible to use a very reliable microswitch manufactured in large series in applications having strokes which may exceed 15

  millimeters and that with a microswitch whose displacement of the button-

  pusher does not exceed 1.5 millimeters.

Claims (14)

  1. Electric switch comprising a push button (12, 52) sliding, along a translation axis XX ', in a body (14, 54) held in a base (56), the push button being able to pass from a position pulled at rest to a position pressed in at work to actuate an electrical switch (16, 58), the pusher being returned to the rest position by a return spring (39, 84), characterized in that the body can be pressed more or less deeply into the base under the action of a force applied to the body along the axis of translation, and in that the switch includes means (100, 102) for holding the body in the base in a selected depressed position , with a holding force greater than that of the spring. 2. Electric switch, according to claim 1, characterized in that the penetration stroke of the body (54) is much greater than stroke of the pusher (52).   3. Electric switch according to one of claims 1 or 2,   characterized in that the contactor is a microswitch (58) having a push button (86) of stroke less than that of the push button (52) of the switch, an actuating spring (88) being placed between the push button   (52) of the switch and the push button (86) of the microswitch.   4. Electric switch according to one of claims 1 to 3,   characterized in that an outer surface of the body (92, 94) is in close contact with a corresponding surface of the base (96, 98), the   maintenance being ensured by a friction force between these surfaces.   5. Electric switch according to one of claims 1 to 3,   characterized in that a surface of the body (92, 94) is provided with ridges (100) and a surface of the base (96, 98) is provided with ridges corresponding (102).   6. Electric switch according to one of claims 1 to 3,   characterized in that a surface of the body (92, 94) is provided with teeth and a corresponding surface of the base (96, 98) is provided with notches, or vice versa.   7. Electric switch according to claim 6, characterized in   this the teeth and the notches have surfaces inclined with respect to the axis of translation.   8. Electric switch according to one of claims 6 or 7,   characterized in that surfaces on one side of the teeth and on the side of the notches, in contact during the extraction of the body of the switch, are substantially perpendicular to the axis of translation, and that surfaces of the other side of the same teeth and the same notches in contact when the body is inserted, are more or less inclined relative to this same axis XX '.   9. Electric switch according to one of claims 1 to 3,   characterized in that an external surface of the body is provided with bosses and a corresponding surface of the base is provided with depressions, or vice versa   10. Electric switch according to one of claims 1   to 9, characterized in that the body (54) can be removed manually at   using a tool after insertion.   11. Electric switch according to one of claims 5 to 10,   characterized in that the body (54) and the base (56) of the switch are made of plastic material ensuring a certain flexibility of their walls and the passage of the grooves or teeth of the body over those of the base during a   depression or extraction of the body in the base.   12. Electric switch according to one of claims 3 to 11,   characterized in that the microswitch (58) comprises a push button (86) located approximately in the translation axis XX 'under an internal part (74) of the push button (52), the push button being controlled by the   actuating spring (88) compressed during the action of the pusher (52).   13. Method for implementing a switch serving to detect the stop position (130) of a movable control member (126) against a fixed element (122, 128), consisting in using a switch (50) having a pusher (52) sliding in a body (54) and returned by a return spring (84) to a rest position, the body being inserted in a base O (56) carried by the fixed element (122), and being able to assume positions more or less sunk into the base by pushing in force in translation, the body being held in this position by a holding force greater than that of the return spring, the implementation consisting in initially inserting the body in the base in a slightly depressed position, then actuating the mobile control member (126) to its stop position (130) to push the body into a position which is   automatically adjusted in depth.   14. Method according to claim 13, characterized in that the movable control member (126) is a door, the fixed element (122, 128) is a frame of the door, the switch (50) is a switch for detecting the open or closed state of the door, and in that the depression of the body (54) of the switch is automatically adjusted by the first closing   of the door, when it comes into contact with its frame.