FR2785063A1 - Control knob drive for heating, ventilation or air conditioning unit in motor vehicle - Google Patents

Abstract

The control has a rotary knob (20) engaging with controls for motor-fan units and an air control vane. The coupling is through a first and second pinion (21,41) coupled through an intermediate gear (31) so that the second pinion (41) follows a to-and-fro rotary motion when the first pinion rotates in a single direction. The knob has a coupling (10,11) engaging with the air control vane.

Description

Controlled member of a ventilation, heating and / or air conditioning installation of a passenger compartment, in particular of a motor vehicle
The invention relates to the field of control members of a plurality of elements of a ventilation, heating and / or air conditioning installation of a passenger compartment, in particular of a motor vehicle.

A control member of this type can cooperate with respective means for adjusting a first element and a second element of the installation, with a view to ensuring coupled control of these two elements.

Control members of the aforementioned type are generally used to regulate the speed of a motor-driven fan unit which includes one of the aforementioned elements of the installation.

The other element may include, for example, a mixing flap to adjust the temperature of a ventilated air flow in the passenger compartment, or even a flap to direct an outdoor air flow or a recirculated air flow in the passenger compartment.

The aforementioned control member is then arranged to cooperate with means for adjusting the position of a shutter of this type, as well as means for adjusting the speed of the group.

The control members used usually comprise a rotary button capable of occupying a plurality of predetermined positions which each correspond to a pair of respective adjustments of the speed of the motor-fan unit and of the position of the flap. The positions which the rotary button can occupy are generally symmetrical with respect to a predetermined axis, perpendicular to the axis of rotation of the button, and two symmetrical positions with respect to this axis correspond to the same adjustment of the speed of the fan unit.

Such known control members, in particular for regulating the speed of a motor-fan unit and another element of the installation, cooperate with two separate connectors of a module for varying the speed of the motor-fan group. Each connector generally comprises a plurality of conductive electrical tracks, whether or not connected to electrical resistors. Thus, the number of parts to be provided (connectors, electrical tracks, electrical resistances, etc.) is doubled compared to a simple control member of a motor-fan unit. Such a complicated structure entails high cost and high manufacturing time.

The present invention improves the situation.

It starts from a control member of the aforementioned type, comprising a rotary button arranged to cooperate with respective adjustment means of at least a first and a second element of the installation. This button is able to occupy a plurality of predetermined positions each corresponding to a pair of respective settings of the first and second elements. These positions are located on either side of a predetermined axis, perpendicular to the axis of rotation of the button and two positions on either side of this axis correspond to the same setting of the first aforementioned element.

According to a general characteristic of the invention, the control member comprises a first pinion fixed to the button and of axis of rotation substantially coincident with the axis of rotation of the button. It further comprises a second pinion of axis of rotation substantially parallel to the axis of rotation of the button and arranged to cooperate with the means for adjusting the aforementioned first element. Finally, the control member comprises intermediate gear means, interposed between the first and second pinions. In addition, the first pinion and / or the intermediate gear means comprise at least two sets of separate teeth so that the second pinion adopts two successive rotational movements in opposite directions when the first pinion pursues an angular stroke in the same direction. , between two extreme positions.

Finally, the rotary button further comprises means for cooperating with the means for adjusting the aforementioned second element.

In a first embodiment of the present invention, the intermediate gear means comprise an intermediate pinion, the second pinion and this intermediate pinion being arranged to mesh with each other while being arranged substantially in two respective planes, perpendicular to the axis of rotation of the button. Furthermore, the first pinion, integral with the button, comprises first and second toothed rings which extend over selected angular ranges, less than 180 and disposed respectively on either side of the axis of rotation of the button, while being in two respective planes substantially perpendicular to the axis of rotation. These respective planes are chosen so that the first ring is arranged to mesh with the intermediate pinion without meshing with the second pinion, while the second ring is arranged to mesh with the second pinion without meshing with the intermediate pinion.

In a second embodiment of the control member according to the invention, the intermediate gear means comprise two racks capable of cooperating with the second pinion, substantially parallel, fixed relative to each other and arranged on either side of the axis of rotation of the second pinion, on the one hand, and on either side of an axis perpendicular to the axis of rotation of the second pinion, on the other hand. The intermediate gear means further comprise a third rack, substantially parallel to the two aforementioned racks and fixed relative thereto.

This third rack is arranged to mesh with the first pinion. Thus, when the first pinion pivots in the same direction of rotation, it drives the racks in translation. In particular, one of the two racks drives the second pinion. When the first pinion continues its rotational movement, the second pinion meshes with the other rack and thus adopts two successive rotational movements in opposite directions.

Preferably, the first element comprises a motor-fan group of the aforementioned type and the second pinion is fixed to a switch that includes a speed variation module of the motor-fan group. Furthermore, the second element of the installation includes a shutter capable of orienting an air flow and the rotary button carries, along its axis of rotation, a distal rod one end of which is secured to a lever a clean cam to move the shutter.

In particular, this shutter is designed to open or close an outside air duct and a recirculated air duct for the installation.

Other advantages and characteristics of the invention will appear on reading the detailed description below, given by way of example, and on examining the appended drawings in which: FIG. 1 represents a schematic front view of a control member coupled to a ventilation, heating and / or air conditioning installation of a motor vehicle cabin in the example described, according to a preferred embodiment of the present invention, FIG. 2 very schematically represents the interactions of the control member with elements of the installation, FIG. 3 represents a partial view of the control member represented in FIG. 1, showing in particular the gears of the control member according to the first mode of abovementioned embodiment, FIG. 4A represents a partial side view of the rotary button comprising two toothed rings on a circular base 20, FIG. 4B represents a view of side of the aforementioned first intermediate, FIG. 4C represents a side view of the aforementioned second pinion, FIG. 5A represents a partial exploded view of the control member of a motor-fan unit and of a recirculation device d 'air, in the example described, - Figure 5B shows a partial exploded view of the control member shown in Figure 5A, from another angle of view, - Figures 6A, 6B and 6C show in front view the control member, showing in particular the interactions between the toothed rings and the aforesaid pinions, when the rotary button is actuated clockwise, FIGS. 6D, 6E and 6F partially represent the control member in front view, when the rotary button is actuated anti-clockwise, and FIG. 7 partially represents a front view of a control member comprising a set of racks substantially parallel to each other, according to a second form of r realization of the present invention.

The detailed description below and the attached drawings essentially contain elements of a certain nature. They can not only serve to better understand the invention, but also contribute to its definition, if necessary.

First of all, reference is made to FIG. 1 to describe a coupled control member 1 of a ventilation, heating and / or air conditioning installation of a passenger compartment, of a motor vehicle in the example described. This control member comprises a rotary button inserted in a front panel 2 of the dashboard of the motor vehicle. The rotary button of the control member 1 can occupy a plurality of positions 3, between two predetermined extreme positions 71 and 81. The control member 1 is arranged to control the speed of a motor-fan unit 15 (FIG. 2 ) and, in a coupled manner, the position of a flap 14, for air recirculation in the example described. The rotary button has a top face provided with an indicator 23 of the position of the rotary button. Thus, the arrangement of the indicator 23 opposite the marking of a chosen position 3, corresponds to a predetermined adjustment of the speed of the motor-fan unit and of the position of the flap 14. Such a configuration of the control member allows you to adjust two aerothermal parameters chosen in the passenger compartment, from a single control button.

Between the two extreme positions 71 and 81, the rotary button can occupy a plurality of positions (ten in the example described), defining an angular travel of the indicator 23 and, consequently, of the rotary button. In the example, this angular travel is less than 360, and subdivided into three successive sections 7, 9 and 8. A first section 7 (represented with horizontal hatching) corresponds to a position of the recirculation flap in which it this allows outside air to feed the passenger compartment of the vehicle. The marking 6 that comprises the front 2 near the first section 7 corresponds to this position of the recirculation flap 14. This first section called in what follows "outside air" extends between positions 71 and 72 of the rotary button, between which the speed of the motor-fan unit decreases monotonously.

The marking 4 on the front panel 2 indicates a variation in speed of the motor-fan unit between these positions.

This variation in speed naturally corresponds to a variation in the speed of the ventilated air in the passenger compartment.

The aforementioned second section 8 (represented by oblique hatching in FIG. 1) extends, symmetrically with respect to the first section 7, between two positions 81 and 82.

The speed of the motor-fan unit decreases in monotonic function between the extreme position 81 and the position 82. In this second section 8, the control member 1 manages the position of the recirculation flap 14 so as to mainly allow a flow of d recirculated air in the passenger compartment. The position of the recirculation flap 14, when the indication 23 of the rotary button is opposite one of the positions of the second section 8, will be called in what follows "recirculated air". The marking 5 that FIG. 2 comprises near the second section 8, corresponds to this position of the recirculation flap 14. The first section 7 and the second section 8 are then, in the example described, symmetrical with respect to the axis YY perpendicular to the axis of rotation of the button XX (figure 2). Between the two sections 7 and 8, the rotary button traverses a third section 9 (represented by vertical hatching in FIG. 1) on which the control member switches the recirculation flap 14 between the two "outside air" positions and "recirculated air" above.

Thus, from the extreme position 71 to the extreme position 81, the control member 1 monotonically decreases the speed of the motor-fan unit, while the recirculation flap 14 closes a recirculated air duct 18 (FIG. 2 ). Then, on the third section 9, the control member switches the recirculation flap 14 to open a communication with the recirculated air duct 18. Finally, on the second section 8, the speed of the motor-fan unit increases to again monotonically, while the recirculation flap 14 closes the outside air duct 17 (FIG. 2).

In the example described, the control member 1 is arranged to adjust the speed of the motor-fan unit in increments.

In practice, the control member cooperates with a switch of a speed variation module of the motor-fan group, this switch being arranged to occupy four positions in the example described, corresponding to a zero speed "0", a medium low speed "1", medium speed "2", medium high speed "3", and high speed "4", maximum.

Reference is now made to FIG. 2 to describe the interactions of the control member according to the invention with elements of the ventilation, heating and / or air conditioning installation of the passenger compartment of the motor vehicle.

In the example shown, the rotary button 1 comprises a distal rod 10, the end 11 of which is secured to a lever of a cam 12 arranged to move an air recirculation flap 14 in the passenger compartment. In practice, the flap 14 moves between two extreme positions in which it respectively closes an outside air duct 17 and a recirculated air duct 18 communicating with the passenger compartment of the vehicle.

Thus, when the indicator 23 is facing the first section, the flap 14 closes the duct 18 and lets the outside air from the duct 17 penetrate into a main duct 19 intended to supply the passenger compartment. When the indicator 23 is opposite the second section 8, the flap 14 closes the outside air duct 17, while the duct 18 which conveys air from the passenger compartment can communicate with the main duct 19. It is provided in the duct 19 a motor-fan unit 15 suitable for driving a turbine 16 in rotation so as to produce an air flow (arrow F), intended to be heat treated, in particular by passing through heat exchangers, and to finally be distributed in the passenger compartment by distribution outlets (not shown). The control member 1 is further arranged for controlling the motor-fan group 15 of the installation, by connection means 13, comprising in particular a speed variation module of the motor-fan group.

Such a module usually includes a plurality of resistors (not shown) and a switch capable of mechanically occupying a plurality of positions in which it connects or not at least one resistance to a power source, generally in the region of 12 volts, d on the one hand, and on the motor of the motor-ventilator group, on the other hand. Usually the switch may include a rotary button capable of occupying a plurality of positions and provided with a conductive pad, integral with the rotary button and arranged to move on conductive electrical tracks connected to the terminals of the aforementioned resistors. The shoe is connected to the voltage supply, while the resistors are generally connected in series, the last resistor being connected to the motor of the motor-fan unit. Such a set of resistors usually forms a voltage divider bridge. The position of the shoe then defines a selected voltage across the motor of the motor-fan assembly.

The second pinion 40 (FIG. 3) is intended to be fixed to a switch provided, in the example, with a conductive pad suitable for moving on electrical tracks (not shown). Thus, the second pinion 40 here plays the role of the usual rotary knobs of the control members of motor-fan groups.

According to a first embodiment shown in FIG. 3, the rotary button 1 comprises a base 20 provided with two toothed rings 21 and 22 arranged respectively in a lower plane and in an upper plane, perpendicular to the axis of rotation of the button. The upper ring 22 can cooperate with an intermediate pinion 30 having a high toothing 31 which, in the example shown in FIG. 3, is a toothed ring. As a variant, the pinion 30 may comprise a toothed wheel over its entire periphery (FIG. 4B). The toothed ring 21, in a lower stage, can, for its part, mesh with the second pinion 40 fixed to the switch and comprising a low toothing which, in the example described, is a lower toothed ring 41. As a variant, the second pinion may include a lower gear over its entire periphery (Figure 4C).

As described above, the distal rod 10 is fixed to the base 20 of the rotary button 1 and its end 11 is intended to cooperate with a cam lever 12 of the recirculation flap 14. This rod is preferably housed in a recess that includes the support wall 25 of the control member.

The second pinion 40 comprises an integral base 42 provided with a notch 43. With reference to FIG. 6A, the notch 43, opposite a marking (Vo, V1, V2, V3 and V4) makes it possible to view the speed of the motor-fan unit associated with the position of the second pinion 40. In practice, a conductive shoe of the aforementioned type, integral with the pinion 40, is capable of moving on electrically conductive tracks, connected to connection pins that comprise a base 44 secured to the support wall 25 of the control member 1. These connection pins are intended to be connected to the resistors of a speed variation module of the motor-fan unit. The second pinion 40 is, in turn, housed in rotation, around a substantially annular wall 45 that comprises the support wall 25. There are also provided means for fixing (not shown) the wall 25 to the facade 2 of the vehicle dashboard.

Thus, the base 20 (FIG. 4A) of the rotary button 1 comprises a high toothed crown 22 arranged to mesh with the pinion 30, and a low toothed crown 21 arranged to mesh with the second pinion 40 mechanically connected to the speed variation means. of the motor-fan unit.

The intermediate pinion 30 comprises, in an upper part, a toothed wheel 31, intended to cooperate with the high toothed crown 22 of the rotary button. The pinion 30 (FIG. 4B) further comprises a peripheral recess in its lower part so as not to hinder a rotary movement of the lower toothed crown 21 that the base 20 of the button comprises. The pinion 40 fixed to the switch (FIG. 4C) comprises in a lower part a wheel 41 suitable for meshing on the one hand with the wheel 31 of the pinion 30, and, on the other hand, with the low toothed crown 21 of the rotary button. The second pinion 40 has, in an upper part, a peripheral recess to allow the high toothed crown 22 of the rotary button to pivot freely. Thus, the respective thicknesses of the toothed wheels 31 and 41 of the pinions 30 and 40 are chosen, on the one hand, so that they can mesh with one another and, on the other hand, to allow free rotation of the toothed crowns 21 and 22, respectively.

The rotary housing 45 which the support wall 25 of the control member according to the invention comprises, carries, at a chosen point on its periphery, spring means 48 (a U-shaped metal spring in the example described ), able to cooperate with a protuberance 46 which comprises the base 42 of the second pinion 40, to form stop means of the rotary button 1 when the latter is in one or other of its two aforementioned extreme positions 71 and 81. The rod 10 which comprises the base 20 of the rotary button 1 is housed in rotation in an opening 261 which comprises a bottom wall 26 of the dashboard of the vehicle. Furthermore, the base 42 of the second pinion 40 is rotatably housed in the peripheral recess 45 which the support wall 25 of the control member comprises, which carries a protuberance 45b intended to be introduced into a rotary housing 262 of the bottom wall 26. The protuberance 45b is then arranged to receive the switch of the motor-fan unit 15. Finally, the base 44 comprising the connection pins is housed in the recess 263 that the bottom wall has 26.

Reference is now made to FIG. 6A to describe the relative movements of the rotary button and of the pinions 30 and 40. To visualize the different positions of the base 20 of the button, a notch 24 is represented on the base 20 (in the North position -Is in Figure 6A). When the rotary button undergoes a clockwise rotation movement, the ring gear 22 meshes with the wheel 31 of the intermediate pinion 30, which is then driven in rotation in a counterclockwise direction. The toothed rings 31 and 41 of the pinions 30 and 40 are chosen to be of sufficient thickness to mesh with one another. The rotation of the pinion 30 then causes that of the pinion 40 fixed to the switch in the same rotary direction as that of the base 20 of the rotary knob 1. The notch 43 of the base 42 of the second pinion 40 then moves from the position VO at position V1.

Thus, the configuration of the pinions 30 and 40 and of the base 20 of the rotary button, as shown in FIG. 6A, corresponds to zero speed of the motor-fan group, with the recirculation flap 14 closing the inlet of the duct. outside air 17 to let a flow of air from the passenger compartment recirculate in the central duct 19 (recirculated air duct 18 open).

As shown in FIGS. 6B and 6C, the ring gear 22 extends over a sufficient angular range for the notch 43 of the base 42 to be able to move from the position VO (zero speed) to the position V4 ( maximum speed), occupying successive positions corresponding to a speed of the motor-fan unit increasing in monotonic function. In practice, the first and second sections 7 and 8 shown in FIG. 1 extend over respective ranges substantially equivalent to the angular ranges of the first and second crowns 21 and 22. The first and second crowns are moreover symmetrical with respect to a axis perpendicular to the axis of rotation of the base 20. Preferably, the angular ranges of the first and second rings are close to 90, as shown in FIG. 6A in particular. Likewise, the first and second sections 7 and 8 extend, in the example described, over respective ranges substantially symmetrical with respect to the predetermined axis Y-Y, and preferably over ranges close to 90.

In a variant, the first and second sections 7 and 8, arranged on either side of the axis YY, are not symmetrical with respect to this axis, in particular when the intermediate pinion 30 is of diameter different from the second pinion 40. The angular differences between the positions on the first section, on the one hand, and on the second section, on the other hand, are then different.

It is also possible to provide toothed sectors with different teeth on the rotary button, to generate different angular steps between the positions from one section to another.

Thus, when the recirculation flap 14 closes the external air duct 17 (FIG. 6A, FIG. 6B, FIG. 6C), the second pinion 40 can cooperate with the base 20 of the rotary knob via the pinion 30.

When the rotary button 1 is actuated anti-clockwise (FIG. 6D), the low toothed crown 21 meshes directly with the toothed wheel 41 of the second pinion 40, while the peripheral recess that the intermediate pinion 30 has in its lower part allows free movement of the bottom toothed wheel 21. The second pinion 40 then moves in the opposite direction relative to the base 20. Thus, it appears that the notch 43 of the base 42 of the second pinion moves in the same direction as that shown in FIGS. 6A, 6B and 6C. The speed of the motor-fan unit increases again monotonously from FIG. 6D to FIG. 6F.

The intermediate pinion 30, permanently meshing with the pinion 40 fixed to the switch, then undergoes a rotation in the same direction as the base 20 of the rotary button. However, the rotation of the pinion 30 in the configurations shown in FIGS. 6D, 6E and 6F, does not in any way modify the adjustment of the speed of the motor-fan group; the pinion 30 then turns "empty".

Thus, from the extreme position 71 to the other extreme position 81, when the rotary button always pivots in the same direction of rotation, the pinion 40 fixed to the switch pivots in the same direction over approximately half of the angular travel of the button, and in the opposite direction for the other half of the angular travel of the button, thus defining a movement of "back and forth".

Reference is now made to FIG. 7 to describe a control member according to the aforementioned second embodiment.

In this embodiment, the above-mentioned intermediate gear means are produced in the form of a part 320 provided with three racks 321, 322 and 323, mutually parallel and fixed with respect to each other. The three racks are all arranged so that their translation takes place along axes perpendicular to the axes of rotation of the button and of the second pinion (XX and X'-X '), on the one hand, and to the axis Y'-Y'perpendicular to these two axes, on the other hand. The two racks 321 and 322 are mounted on either side of the pinion 40, and offset relative to each other (to the left and to the right respectively in FIG. 7). In this embodiment, the aforementioned first pinion 20, which comprises the rotary button 1, comprises a simple toothed wheel 21 which meshes with the third rack 323. Thus, when the rotary button 1 is rotated, the toothed wheel 21 cooperates with the rack 323 causing a translational movement of the two racks 321 and 322. When the pinion 40 meshes with one then the other of the two racks 321 and 322, it adopts successive rotational movements in opposite directions.

In particular, when the rotary button 1 rotates clockwise from position 71 to position 81, the pinion 40 first meshes with the rack 321 by turning anti-clockwise, then it meshes with the rack 322 by rotating clockwise. Thus, when the marker carried by the rotary button 1 is opposite the section 7, the pinion 40 cooperates with the rack 321, and when the marker is opposite the section 8, the pinion 40 cooperates with the rack 322. Between the positions extremes 71 and 81, the speed of the motor-fan unit decreases then crolt again from one section 7 to the other 8.

Of course, the present invention is not limited to the embodiment described above by way of example.

It extends to other variants.

Thus, it will be understood that, in the first embodiment described above, the intermediate pinion and the pinion fixed to the switch can include either a toothed wheel, a toothed crown or even two toothed crowns on two levels, as shown on the Figures 5A and 5B. It should also be noted that here, the term toothed wheel gathers, generally, a toothed crown which extends over an angular range less than or equal to 360, or even two toothed crowns of different thicknesses.

On the other hand, it is necessary to provide toothed crowns 21 and 22 that the rotary button carries, of selected angular sector (close to 90 in the example described), less than a predetermined threshold value, so that the toothed crown low 21 does not mesh with the toothed wheel 41 of the pinion 40 (FIG. 6C) when the notch 24 of the rotary button is opposite the extreme position 81 (FIG. 6C), or else so that the high toothed crown 22 does not not meshes with the pinion 30 when the notch 24 is opposite the extreme position 71 (FIG. 6F).

The angular ranges over which the two low and high rings 21 and 22 extend are chosen here close to 90, and are given by way of example. In a variant of the control member according to the invention, these angular ranges can be lower or higher, depending on the chosen range of displacement of the second pinion 40 from one of its extreme positions (VO) to the other (V4 ).

The aforementioned third range 9 preferably extends over an angular range close to 90 or greater than 90. As a variant, this range can be lower, or even eliminated, while the position of the recirculation flap varies continuously from the first section 7 to the second section 8.

In the example described above, the control member according to the invention is arranged to adjust the position of the recirculation flap 14. As a variant, it can adjust the position of a mixing flap of a ventilation installation , heating and / or air conditioning, this mixing flap being capable of closing one or the other of the hot air and cold air conduits, intended to supply the passenger compartment of the motor vehicle. The configuration of the control member would then consist of a "hot air" zone corresponding to the aforementioned first section, on which the engine speed of the fan unit decreases monotonically, and a "cold air" region corresponding to the second section 8, on which the speed of the motor-fan group increases substantially monotonously. Furthermore, the control member described above may comprise a third connection with one of the elements of the installation, such as an air conditioning loop of the installation, for example in a "cold air" position with maximum speed of the motor-fan unit.

The means of cooperation between the rod 10 of the rotary button and the recirculation flap 14 can be different from a cam lever mechanically connected to the flap 14. In fact, they can be formed for example from gear means capable of driving the flap rotation 14.

In addition, the second pinion 40 can be arranged to cooperate with means for adjusting an element other than a motor-fan unit. Indeed, provision may be made, for example, for a rod secured to the second pinion 40 carrying a lever of a cam to adjust the position of another component of the installation.

The various markings and positions of the control member according to the invention are described above by way of example. As a variant, the number of positions of the rotary button, and consequently the number of possible speeds of the fan motor group, may be different.

Finally, the control member according to the first embodiment described above comprises two pinions suitable for meshing with two respective toothed rings of the rotary button. Alternatively, the two pinions can mesh with the crowns via other pinions, the main thing being that the second pinion 40 adopts a "back and forth" rotation movement over a complete angular travel of the rotary button. 1.

Claims (13)

Claims 1. Control member of a ventilation, heating and / or air conditioning installation of a passenger compartment, in particular of a motor vehicle, of the type comprising a rotary button (1,20) arranged to cooperate with respective adjustment means of at least at least a first (15) and a second (14) element of the installation, and capable of occupying a plurality of predetermined positions (3) each corresponding to a pair of respective settings of the first and second elements (14,15), while that two positions of the button on either side of a predetermined axis (YY), perpendicular to the axis of rotation (XX) of the button (1), correspond to the same adjustment of said first element (15), characterized in that it comprises a first pinion (20) fixed to the button (1) and of axis of rotation (XX) substantially coincident with the axis of rotation of the button (1), a second pinion (40) of axis of rotation substantially parallel to the axis of rotation (XX) of the button (1) and arranged to coo pererate with the adjustment means of said first element (15), as well as intermediate gear means (30), interposed between the first (20) and second (40) pinions, in that the first pinion (20) and / or the intermediate gear means (320) have at least two separate sets of teeth (21,22; 321,322) so that the second pinion (40) adopts two successive rotational movements in opposite directions when the first pinion (20) continues an angular travel in the same direction, between two extreme positions (72,82), and in that the rotary button (1,20) further comprises means (10,11) for cooperating with the means for adjusting said second element (14). 2. Control member according to claim 1, characterized in that the rotary button (1,20) comprises, along its axis of rotation (XX), a distal rod (10) carrying, at one of its ends (11), said adjusting means (12) of the second element (14) of the installation. 3. Control member according to claim 2, characterized in that the second element of the installation comprises a flap (14) capable of orienting an air flow, and in that the end of said rod is integral with a lever of a cam (12) capable of moving said flap (14). 4. Control member according to claim 3, characterized in that the flap (14) is arranged to open or close an outside air duct (17) and a recirculated air duct (18) of the installation. 5. Control member according to one of the preceding claims, characterized in that the intermediate gear means comprise an intermediate pinion (30), the second pinion (40) and said intermediate pinion (30) being arranged to mesh with each other while being arranged substantially in two respective planes, perpendicular to the axis of rotation (XX) of the button, in that the first pinion (20) comprises a first (22) and a second (21) toothed rings, extending over selected angular ranges, less than 180 and disposed respectively on either side of the axis of rotation (XX), substantially in two respective planes perpendicular to the axis of rotation of so that the first ring (22) is arranged to mesh with the intermediate pinion (30) without meshing with the second pinion (40), while the second ring (21) is arranged to mesh with the second pinion (40) without meshing with the intermediate gear area (30). 6. Control member according to one of claims 1 to 4, characterized in that the intermediate gear means (320) comprise two substantially parallel racks (321,322), fixed relative to each other and arranged on either side of the axis of rotation of the second pinion (40), on the one hand, and on both sides of an axis perpendicular (Y'-Y ') to the axis of rotation of the second pinion (40), on the other hand, as well as a third rack (323), substantially parallel and fixed relative to said two racks, arranged to mesh with the first pinion (20). 7. Control member according to one of the preceding claims, characterized in that said first element comprises a motor-fan group (15) of the installation, and in that the second pinion (40) is fixed to a switch that includes a speed variation module of the fan unit (15). 8. Control member according to claim 7, characterized in that the rotary button (1) is arranged to pivot between two extreme positions (71,81) defining an angular stroke less than 360 and comprising: a first section (7) on which the speed of the fan unit (15) decreases monotonically while the second pinion (40) pivots in the opposite direction to the button (1), and a second section (8) on which the speed of the fan group (15) grows monotonically while the second pinion (40) pivots in the same direction as the button (1). 9. Control member according to claim 8, taken in combination with claim 4, characterized in that, on the first section (7), the flap (14) is arranged to close the recirculated air duct (18) and open the outside air duct (17), while, on the second section (8), the flap (14) is arranged to close the outside air duct (17) and open the recirculated air duct (18 ). 10. Control member according to one of claims 8 and 9, characterized in that the first and second sections (7,8) extend over respective ranges substantially symmetrical with respect to said predetermined axis (Y-Y). 11. Control member according to claim 10, characterized in that said ranges are close to 90. 12. Control member according to one of claims 8 to 11, taken in combination with claim 4, characterized in that the angular travel of the rotary button (1) comprises a third section (9) adjacent to the first section (7) , on the one hand, and to the second section (8), on the other hand, and on which the flap (14) closes the outside air duct (17) while opening the recirculated air duct (18). 13. Control member according to claim 12, characterized in that the third section (9) extends over an angular range greater than or close to 90.