FR2533747A1 - Abrupt-action electric switch and switching unit formed of several switches - Google Patents

Abstract

The invention relates to the electrical industry and, more particularly, the switches used to control automobile accessories. A rocking lever 26 acts, via fingers 30, on a slit elastic plate 2 carrying the movable contact 16. At its end the lever 26 carries a heart-shaped cam 36 with which a locking bar 38 cooperates. A spring 44' returns the lever 26 to high position. The switch is controlled, on opening and closing, by pushing the control button.

Description

Snap action electrical switch and switch assembly consisting of multiple switches.

 The present invention relates to improvements made to snap-action electrical switches of the known type comprising, on the one hand, a thin plate of elastic metal divided, by two longitudinal slots, into three bands, at least one of which is s supports and can switch on a support between two positions in at least one of which a movable contact carried by said plate is pressed against a fixed contact secured to the support and, on the other hand, a pivoting actuating lever which can also switch on said support and which carries at least one finger to actuate said wafer by sliding support along one, at least, of the other strips of the wafer.

A switch of this type has been described for example in French patent No. 2,221,801, in the name of the Company
DAV. I1 has the advantage, thanks to the sudden tilting of the movable contact carrier plate due to an effect of "exceeding neutral point", to allow the establishment and cutting of high intensity currents (for example several amperes) despite a small footprint of the device.

 Such switches are widely used in the automotive industry for controlling many electrical circuits. For most applications, these switches have their two positions (work and rest) which are naturally stable, thanks to the dead center override effect which triggers the movable contact carrier plate to one or other of its positions and keeps it there.

 I1 follows that the control button, which is generally integral with the tilting actuating lever, must be actuated by the operator in one direction to establish the working position and, in the opposite direction, to return to the rest position.

 In recent years, we have sought to simplify the operation of electrical switches, with the so-called "push-push" switches in which the operator pushes the control key to establish the working position and pushes the same key again to return to the rest position.

 These push-push switches are widely used on television, radio, etc. devices, but do not generally allow the cutting of high currents, since, most often, they do not operate by snap action. .

The object of the present invention is to provide a snap action switch, of the aforementioned type, which can be
controlled according to the "push-push" principle, that is to say that a first push on the control button brings the switch to the working position and a second push on the same button brings the switch back to the rest position .

 The invention also aims to provide a push-push switch with snap action and short stroke, that is to say in which the stroke that the operator must make the control key is less , for example two times lower, than that required to operate conventional push-push switches, with identical current cut-off capacity.

 The subject of the invention is a snap-action switch of the aforementioned type, in which one of the ends of the actuating rocker lever, distant from the rocker axis of said lever, carries a cam with a "heart" profile; in which the switch support carries a movable locking bar cooperating with said cam in the heart, and wherein elastic return means are provided to urge the actuating lever towards one of its positions.

 According to the invention, the control button, which is actuated by the operator, may be integral with the actuating lever or may be separate from this lever, by being mounted sliding or pivoting in the support and acting only in thrust on the actuation lever.

The invention also relates to switching assemblies, formed by several switches as defined above, in particular the assemblies used on the
electrical, automotive for controlling a plurality of equipment / these switch assemblies generally being mounted on the dashboard, on a console or on the steering wheel.

 The invention will be better understood on reading the detailed description which follows and on examining the appended drawings which represent, by way of nonlimiting examples, several embodiments of the invention.

 Figure 1 is a schematic representation of a switch according to the invention.

 Figure 2 is a plan view of the plate - 'elastic movable contact carrier.

 Figure 3 is a plan view of the locking cam.

 Figure 4 is a sectional view, partially in perspective of a switch according to the invention, with sliding control touch.

 Figures 5, 6, 7 are schematic representations of other embodiments.

 Figure 8 is a sectional view of another embodiment of a switch with additional contacts.

Figure 9 is a sectional view along the line
IX-IX of figure 8.

 Figure 10 is a sectional view of another embodiment, with tilting control button.

 FIG. 11 is a simplified representation of a double switch according to the invention.

 Figure 12 is a plan view of a switching assembly according to the invention.

Figure 13 is a sectional view along the line
XIII-XIII of figure 12.

 The switch shown schematically in Figure 1 comprises a thin plate of elastic metal 2, divided by two longitudinal slots 4, 4 'in three strips 6, 8, 8' (Figure 2).

 The central strip 6 rests on the end of a contact plug 10 for current supply secured to the support or housing 12 of the switch, an orifice 14 drilled in the - branch 6 being threaded on the end of the contact sheet 10.

 The plate 2 carries a movable contact 16 which comes to press on a first fixed contact 18 carried by a second contact plug 20 secured to the support 12, or on a second fixed contact 22 carried by a third contact plug 24 also secured to the support 12 .

 The plate 2 can switch from one to the other of its two positions under the effect of an actuating lever 26 which can pivot around an axis 28 in the support 12 and which carries two lateral fingers 30 of which the end bears sliding support (at 32, FIG. 2) along the branches 8, 8 ′ of the plate. As is known, by an effect of overcoming neutral, the plate suddenly switches from one to the other of its positions when the actuation lever 26 is tilted, in one direction or in the 'other.

 In accordance with the invention, the lever 26 carries at one of its ends 34, distant from the baculating axis 28, a heart cam 36 (or labyrinth cam), of well-known profile, which is shown more on a large scale in FIG. 3. A movable locking bar 38 is mounted on the support 12 (FIG. 1) and its curved end beak 40 cooperates with the cam 36 by penetrating into the winding path which constitutes the heart-shaped cam and bypassing the heart-shaped central part 42 of the cam.

 The bar 38 is advantageously constituted by a flexible metal rod, of the piano string type, the curved beak 40 of which is guided by the profile of the groove of the cam 36.

 The switch according to the invention also comprises an elastic member for returning the actuating lever which has been shown in FIG. 1 in the form of a spring 44 which bears, on the one hand, against the lever 26 and , on the other hand, against part of the support 12.

 In a switch according to the invention, the control can be made by the operator directly by pushing on a control key integral with the operating lever 26, but provision is preferably made, as shown in FIG. 1, control key 46 which is mounted mobile, for example sliding, in the upper part 48 of the housing 12 of the switch and which is separate from the lever 26. The key 46 may comprise a projecting part 50 whose end comes to act in thrust in a pressure zone 52, for example hollow, of the lever 26.

Preferably a light spring 54 recalls the key 46 in the projecting position.

 To operate the switch from the position shown in Figure 1, simply press the button 46 and release it. Upon insertion, the end of the fingers 30 of the lever 26 moves in the clockwise direction (in FIG. 1) by traversing the zones 32 of the plate 2 which suddenly switches to the position or the movable contact 16 comes to bear against the contact 22. During this movement, the spout 40 of the bar 38 traverses the left part of the groove of the cam 36 (FIG. 3) from the position marked 40 in this figure.

 When the control button 46 is released, the lever 26 rises under the effect of its spring 44 until the spout 40 of the bar 38 hooks into the hollow part of the heart 42 of the cam (position 40 ' in Figure 3) and locks the lever in this working position.

The control key 46 finishes returning to its initial position under the effect of its return spring 54.

 To return to the position in FIG. 1, the operator must still press and release the key 46. When pressed again, the cam 36 is lowered and the spout 40 of the bar runs along the right part (FIG. 3) of the cam 36 which is unlocked. When the pressure on the control key is released, the lever 26 returns freely, under the effect of its spring 44, to its high position, by suddenly tilting the plate 2 while the spout 40 of the bar returns to the position marked 40 in Figure 3.

 A snap-action switch is thus produced which is controlled only by pressing the control key, according to the "push-push" system.

 it should be noted that this switch has still other advantages: there is an audible and tactile click on switching on and off, which is convenient for the user; the contacts are strongly supported and stable in the two positions, which allows the passage of large currents and which makes it possible to resist shaking in the case where the switch is mounted on an automobile. For example, in the locked position, the locking by the heart-shaped cam is very safe since the return spring 44 tends to press the hollow bottom of the heart 42 against the spout 40 of the bar 38, without the risk of inadvertent unlocking in the event of shake.

 On the other hand, thanks to the fact that the cam 36 is carried by the end 34 of the lever 26, as far as possible from the pivot axis 28, this cam benefits from a relatively large stroke, even if the switch is small footprint, which makes its operation even safer.

 Finally, the switch according to the invention lends itself particularly well to the realization of a short stroke control. Thanks to the fact that the pressure zone 52 is located in the intermediate part of the actuating lever, between the cam 36 and the tilting axis 28, at a short distance from this axis, an amplification effect is produced which allows, with a small stroke of the control button, for example about 2 mm, to obtain a greater stroke, for example 4 to 5 mm, of the cam located G the end of the lever 26. This construction, using the abrupt contact previously described, allows switching of high currents, for example up to 15 amps, despite the short stroke of the button 46.

 There is shown in more detail in Figure 4 a switch according to the invention corresponding substantially to the simplified diagram of Figure 1 and bearing the same reference numbers. The support 12 constitutes the housing of the apparatus in which the control key 46 can slide.

In this embodiment, the return spring
the actuating lever 26 is constituted by a helical spring 44 'which is housed in a cylindrical cavity 56
hollowed out in the central part of the lever 26 and which opens out between the lateral fingers 30. The spring 448 bears, on the one hand, against the bottom of this cavity and, on the other hand, against the interior face opposite the housing 12 and it acts in flexion, to bring the lever 26 back to the high position shown in FIG. 4.

 There is also shown in more detail in FIG. 4 the mounting of the locking bar 38, the spout 40 of which cooperates with the core cam 36. This bar is formed by a piano cord whose lower end 58 is folded at an angle straight and is retained, against the bottom of the housing 12, by a plate or clip 60 leaving the bar 38 the freedom to oscillate slightly so that its beak 40 can freely follow the contour of the cam 36. The clip 60 also ensures braking the lever 38 to allow operation in all positions.

 The contact sheets 10, 20, 24 can be formed, as is usual, by flat tongues, or even by cylindrical pins, fitting into a printed circuit board 62.

 So far, with reference to FIGS. 1 and 4, the actuating lever 26 has been described with the fingers 30 perpendicular to this lever, to form a bent lever with two arms, and with the cam 36 at the end of the arm 26.

 However, other arrangements are possible, as shown diagrammatically in FIGS. 5, 6, 7.

In the case of FIGS. 5 and 6, the heart-shaped cam 36 is carried by the end of a lever arm 64 which forms part of the actuating lever 26 but which is oriented like the fingers 30 of the lever. In FIG. 5, the heart-shaped cam 36 is shown as being carried, at the end of this arm, by the lateral face of the arm perpendicular to the end face 34. In the case of ia figure. 59 the cam 36 is carried by the end face 34, as in FIGS. 1 and 4.

 In the case of. FIG. 6, the fingers 30 are oriented in the extension of the lever 26, the cam 36 being formed on the end face 34 of the lever 26.

 As a variant, FIG. 7 shows the control key 46 ′ as being integral, in the pressure zone 52, with the lever 26.

 The embodiment shown in Figures 8 and 9 is quite similar to that of Figures 1 and 4 with regard to the arrangement of the actuating lever 26, the operating fingers 30, the cam 36, the bar 38 and the sliding control button 46.

 The elastic return means of the lever 26 are however different. In this case, two arms 66 are provided, extending the lever 26 and bearing on pins 68 which project from a cap 70 slidably mounted in the bolt case 12. A spring 44 housed in the cap 70 biases the lever 26 towards its high position.

 Inside the cap 70, it is possible to mount movable contacts 72 which cooperate with fixed contacts 74 carried by the housing 12. It is thus possible to establish additional circuits, by friction contact and not by sudden action as with the wafer 2, with a single switch according to the invention.

 The switch can finally include a warning lamp 76.

 Another embodiment has been represented in FIG. 10 which is similar to that represented in FIG. 5. The lever 26 rocks around the axis 28 relative to the housing 12 and is returned to the position represented in FIG. 10 by a hairpin spring 78. The cam 36 is carried by the end of the lever arm 64 which is oriented, relative to the lever 26, like the operating fingers 30.

 In this embodiment, the control button 46 is pivotally mounted, about an axis 80, with respect to the housing 12 and it is returned, in the position shown, by a leaf spring 82.

 The key 46 acts in thrust, by a portion 84 of its inner surface against a pressure zone or boss 52 'of the actuating lever 26, the distance between the boss 52' and the axis 28 being small, for example half , relative to the distance between the axis 28 and the cam 36, so as to have a short stroke of the control button.

 The elastic return means of the actuating lever have so far been shown in the form of springs (44 or 78), but it is also possible to use the elastic return force of the movable contact carrier plate 2 itself. , without adding any particular return spring. It suffices to choose the stroke of the ends of the fingers 30 and the position of the axis 28 of the lever relative to the point of articulation of the plate 2 so as to obtain a single stable position of the plate, without exceeding the point died for unstable position.

 The actuating lever 26 is also shown in the figures as being provided with two fingers 30 which act on the lateral branches 8, 8 ′ of the plate 2 (FIG. 2). But it is understood that one central finger can be provided, acting on the central branch 6 of the wafer, the latter being in this case supported in a tilting manner, by the ends of the two lateral branches 8, 8 '.

 The invention makes it possible to produce an autonomous switch, in an individual housing of small bulk.

Thus in the embodiment of FIG. 4, the external dimensions a, b, h, can be approximately 24, 22 and 35 mm, respectively, with a current breaking capacity of several amps.

 The switch according to the invention is also suitable for integrating into a modular switching assembly bringing together the control of several electrical devices.

 In FIG. 11, a double switch is schematically shown bringing together, in a common housing 12i, two identical switches 86, 86 'of which only the actuation levers have been shown 26. On the housing 12' is mounted a control key tilting 46 ′ carrying two projecting fingers 50 which act respectively in thrust on each of the levers 26. The control of two separate functions is thus carried out (for example on an automobile the control of direction indicators, of washing and wiping d 'a rear window, etc.), the command to start and stop each function always by pushing on one or the other of the ends of the rocking key 46'.

 On motor vehicles, it is now common to group, for example under the steering wheel or on a console, several control devices for accessories such as sound call, headlights, fog lights, rear window heating, etc.

 This is how one can group, in the same switching assembly 88, several switches (for example 8 in FIG. 12j "lontés in a common support and whose control keys 46 protrude from a common cover 90.

 Figure 13 is a partial sectional view along line XIII-XIII of Figure 12 of a switching assembly according to the invention. The apparatus comprises a support 92, common to all the switches, which essentially comprises a base 94 with respect to which project legs 96 pierced with orifices 97 in which the pivot axes 28 of the actuating levers 26 of the switches rotate. individual.

 The individual switches are for example of the type which has been described in connection with FIG. 4. The base 94 of the common support supports the contact pins 10, 20, the locking bars 38 which cooperate with the heart-shaped cam 36, and pillars 98 on which the cover 90 is fixed. The other members are substantially identical to those of FIG. 4 and bear the same reference numbers.

 Switches have been shown according to the invention intended to function as reversers (FIGS. 1, 4), as switches (FIG. 10) and as multiple switches with additional contacts (FIG. 8), but it is obvious that any other configuration electric can be carried out, with or without lighting of the button (figure 8).

 It is also possible to include, in a switching assembly 88 according to the invention1 such as that shown in FIGS. 12 and 137 one or more switches with a monostable configuration (contactor or breaker) which are of identical construction to that of the switches described above, with an identical actuating lever 26, but in which the locking bar 38 is removed, as it is shown for the switch on the left side of Figure 13.

Claims (13)

REEDICATIOS  1. Snap-action electrical switch comprising, on the one hand, a thin plate (2) of elastic metal divided, by two longitudinal slots (4r 4 '), into three bands, at least one (6) of which presses and can switch on a support (10, 12) between two positions in at least one of which a movable contact (16) carried by said plate is pressed against a fixed contact (18, 22) secured to the support and , on the other hand, an actuating lever (26) which can also tilt on said support (12) and which carries at least one finger (30) for actuating said plate (2) by sliding support along one at least other bands (8) of the plate (2), said switch being characterized in that: one of the ends (34) of said lever, distant from its pivot axis (28), carries a profile cam in the heart (36); the support carries a movable locking bar (38, 40) cooperating with said cam; and elastic return means (44) are provided to urge the actuating lever towards one of its positions.  2. Switch according to claim 1, characterized in that the control button (46 ') on which the operator acts in thrust is integral with the actuating lever (26).  3. Switch according to claim 1, characterized in that the control button on which the operator acts estune movable part (46), separate from the actuating lever (26), which is carried by the support (12) and which acts only when the actuating lever is pushed.  4. Switch according to claim 3, characterized in that the control button (46) is slidably mounted in the support.  5. Switch according to claim 3, characterized in that the control button (46) is pivotally mounted on the support.  6. Switch according to any one of the preceding claims, characterized in that the elastic return means of the actuating lever are constituted by the movable contact carrier plate (2) itself.  7. Switch according to any one of claims 1 to 5, characterized in that the elastic return means of the actuating lever (26) are consti interposed killed by a spring (44, 44 ') / between the support (12 ) and the said lever (26).  8. Switch according to claim 7 characterized in that the spring (44 ') is a helical spring housed in a recess (56) hollowed longitudinally in the lever (26), said spring bearing against the bottom of said cavity and against the support (12) -  9. Switch according to any one of the preceding claims, characterized in that the pressure zone (52) of the control button (46) on the actuating lever (26) is located at a shorter distance, preferably approximately twice as short, from the pivot axis (28) of said lever, as the distance which separates the heart cam (36) from said axis (28).  10. Switch according to any one of the preceding claims 7, characterized in that the actuating lever (26) is coupled to additional movable contacts (72) cooperating, by friction contact, with additional fixed contacts (74) carried by the support (12).  11. Switch according to any one of the preceding claims, characterized in that the actuation lever (26) carries two spaced apart fingers (30) which act on the lateral branches (8, 8 ') of the plate (2)  12. Switch according to any one of the preceding claims, characterized in that it comprises two individual switches (86, 86 ') carried by a common support forming a general housing (12') and in that it comprises a key single remote control (46 '), tiltably mounted on said housing (12') and provided with two projecting parts (50) acting respectively on each actuation lever (26) of the individual switches (86, 86 ') .  13. Switching assembly comprising a -uraîlté of switches according to any one of the preceding claims 7 characterized in that it comprises a support (92), common to all the switches, having a base (94) from which protrude a plurality of feet (96) pierced with orifices (97) in which -turn the pivot axes (28) of the actuating levers (26).