The present invention relates to a rotary switch assembly having a knob rotatable about an axis and provided with a rotation stop assembly comprising a substantially cylindrical coupling surface rotatable about an axis and co-rotating with the knob, and a coupling member mechanically couplable with the coupling surface to stop rotations of the coupling surface. of the invention

Rotary switch assemblies of this kind have many applications, such as for example, in automotive industry. Upon activation, the rotation stop assembly blocks further rotation of the knob indicating that an extreme value of a quantity/parameter controlled with the switch assembly has been reached. To this end, it is known to provide a progressive haptic reaction torque to the knob indicating that this extreme value is being approached and that the assembly is about to achieve its stop position.

Patent publication US2016020045 discloses a rotary switch assembly with a knob. As the knob is rotated on an electronic system such as a radio and a limit is approached and ultimately reached (such as a volume limit), the switch creates a progressive haptic force on the knob to indicate to the operator that the limit is being approached and/or has been reached. For example, when a maximum volume limit has been reached in a radio application, the haptic force can prevent the knob from rotating any further.

It has been the object of the present invention to provide a rotary switch assembly provided with a rotation stop assembly having a relatively simple and compact construction.

Summary of the invention

The invention provides a rotary switch assembly of the kind mentioned in the outset, that is characterised in that said coupling member is rotationally disposed within a locking member about an axis, over a predetermined angular distance limited on both sides with at least one elastic limiting element, wherein said locking member is movable between an inactive position in which said coupling member is mechanically decoupled from said coupling surface, and an active position in which said coupling member is mechanically coupled with said coupling surface and said at least one elastic limiting element provide(s) a progressive haptic reaction torque to the knob.

Preferably a vector normal to the coupling surface is directed toward the axis of its rotation.

Preferably a vector normal to the coupling surface is directed outward from the axis of its rotation.

Preferably the coupling surface is substantially perpendicular to the axis of its rotation.

Preferably the coupling surface and/or said coupling member is/are provided with a toothed rack(s).

Preferably said coupling member is provided with a closed cutout defining at least one blocking surface, said locking member is provided with a blocking element disposed within said cutout, and said at least one elastic limiting element is disposed between said blocking element and said blocking surface.

Preferably said coupling member is provided with at least one open cutout defining a blocking surface, said locking member is provided with at least one blocking element disposed outside of said at least one open cutout, and said at least one elastic limiting element is disposed between said at least one blocking element and said blocking surface of said at least one open cutout.

Preferably said locking member is provided with a toothed rack coupled with a toothed wheel providing a linear movement of said locking member.

Preferably the coupling surface is provided on the knob.

Preferably the coupling surface is provided on a rotatable member.

Brief description of drawings

The invention shall be described and explained below in preferred embodiments and in connection with the attached drawings in which:

Fig. 1 presents a schematic side view of a first embodiment of the rotary switch assembly with a rotation stop assembly in an inactive state (Fig. 1a), upon activation (Fig. 1 b), in a clockwise terminal state (Fig. 1c), and in a counter-clockwise terminal state (Fig. 1d);

Fig. 2 presents a schematic side view of a second embodiment of the rotary switch assembly in an inactive state;

Fig. 3 presents a schematic side view of a third embodiment of the rotary switch assembly in a counter-clockwise terminal state;

Fig. 4 presents a schematic side view of a fourth embodiment of the rotary switch assembly upon activation;

Fig. 5 presents a schematic axonometric view of a fifth embodiment of the rotary switch assembly in an inactive state;

Fig. 6 presents an axonometric view of the first embodiment of the rotary switch assembly upon activation; and

Fig. 7 presents an enlarged detail of the rotary switch assembly shown in Fig. 6.

Detailed of preferred embodiments

In the following description numerical references of elements performing the same functions remain the same in the drawings, wherein suffixes (a, b, ...) were added, where appropriate, to additionally distinct elements having different construction.

A first embodiment of a rotary actuator assembly 1a is shown in Figs. 1 , 6, and 7. It can be used in automotive vehicles but also in other control systems, such as computers, mobile devices, etc. The switch assembly 1a comprises a knob 2 rotatable about an axis A as indicated by an arrow, and provided with a torque application surface 21 for user control. The knob 2 is electrically connected to a vehicle wiring, directly or via an additional gear mechanism, by means of an electrical contact connection, capacitive or any other suitable connection, in a manner well known to those skilled in the art. Rotations of the knob 2 may be employed, for example, for presetting a vehicle control systems, adjusting sound system volume, etc.

In order to block rotations of the knob 2, if necessary, the switch assembly 1a comprises a rotation stop assembly 3a. The rotation stop assembly 3a comprises a substantially cylindrical coupling surface 4a and a coupling member 5a mechanically couplable with the coupling surface 4a. In this embodiment an axis of rotation B of the coupling surface 4a corresponds to the axis A of rotation of the knob 2, and a vector normal to the coupling surface 4a is directed toward the axis B of its rotation.

The coupling member 5a is rotationally disposed about an axis C, substantially parallel to the axis B, on a pin 71 of a locking member 7a over a predetermined angular distance. To this end the coupling member 5a is provided with a closed angular cutout 53 defining blocking surfaces 531 facing each other on the angular direction of rotation of the coupling member 5a about the axis C. The locking member 7a comprises a blocking element 72 projecting inside and in the middle of the cutout 53. Two elastic limiting elements 6 in the form of coil springs are disposed between the blocking element 72 and the blocking surfaces 531 of the coupling member 5a.

The locking member 7a is movable, as indicated by an arrow, along an axis substantially perpendicular to the axis B of rotation of the coupling surface 4a, between an inactive position, shown in Fig. 1a, in which the coupling member 5a is mechanically decoupled from the coupling surface 4a, and an active position, shown in Figs. 1 b-d, in which the coupling member 5a is mechanically coupled with the coupling surface 4a. In this embodiment the coupling surface 4a is provided with a toothed rack 41 , and the coupling member 5a is provided with a toothed cam 51 cooperating with the rack 41 .

To effect the linear movement of the locking member 7a between the inactive and the active position, the locking member 7a is provided with a linear toothed rack 73 cooperating with a toothed wheel 8 rotatable, as indicated by arrow, about an axis parallel to the axis B and driven by means of an electric motor controlled by a suitable control unit (not shown).

In an inactive state of the stop assembly (cf. Fig. 1a) rotations of the knob 2 are not restricted, and the coupling member 5a is positioned in its equilibrium angular position within the locking member 7a with both coil springs 6 expanded to the same extent between the blocking element 72 and the blocking surfaces 531 .

When the control unit determines that the quantity or parameter controlled with the rotary switch assembly 1a is about to approach some predefined value, a signal is generated, and the electric motor drives the toothed wheel 8 which in turn drives the linear toothed rack 73 resulting in a linear movement of the locking member 7a along with the coupling member 5a towards the coupling surface 4a.

In a position shown in Figs. 1 b, 6 and 7 the toothed cam 51 engages with the rack 41 reaching the active position of the stop assembly 3a. Any further rotation of the knob 2 results also in a corresponding rotation of the coupling member 5a, against a pressure of the spring 6 opposite to the direction of the coupling surface 4a rotations, until the spring is compressed to its maximal extent stopping rotations of the knob 2, as shown in Fig. 1c or Fig. 1d.

During rotation of the knob 2 in the active position of the stop assembly 3a the spring 6 is gradually compressed generating a progressive haptic reaction perceptible by a user rotating the knob 2 and indicating that a blocking position shall soon be reached and that the rotary switch assembly 1a approaches its stop position.

A second embodiment of the rotary switch assembly 1b shown in Fig. 2 is a modification of the embodiment 1 a shown in Fig. 1 . Here a rotation stop assembly 3b comprises a coupling surface 4b devoid of a rack, that cooperates with an elastomeric frictional surface 52 of a coupling member 5b.

A third embodiment of the rotary actuator assembly 1c shown in Fig. 3 is also a modification of the embodiment 1a shown in Fig. 1. Here a rotation stop assembly 3c comprises a coupling surface 4c having a normal vector directed outward from the axis B of its rotation. The coupling surface 4c is provided with a toothed rack 41 . A locking member 7c and a coupling member 5c are disposed outside of the perimeter of the coupling surface 4c, and are slidable along an axis substantially perpendicular to the axis B of rotation of the coupling surface 4c. The coupling member 5c is provided with a toothed cam 51 cooperating with the rack 41 .

A fourth embodiment of the rotary switch assembly 1d shown in Fig. 4 is a modification of the embodiment 1 b shown in Fig. 2. Here a rotation stop assembly 3d comprises a coupling member 5d having two open angular cutouts 54, each having a shape of a ring segment and open on the angular direction of rotation of the coupling member 5a about the axis C on its opposite sides. The cutouts 54 define blocking surfaces 541 facing each other on the angular direction of rotation of the coupling member 5d. A locking member 7d comprises two blocking elements 72 disposed outside of the cutouts 54. Two elastic limiting elements 6 in the form of coil springs are disposed within the cutouts 54 between the blocking elements 72 and the blocking surfaces 541 . A frictional surface 4d cooperates with a frictional surface 52 of a coupling member 5d.

A fifth embodiment of a rotary switch assembly 1e shown in Fig. 5 comprises a knob 2 rotatable about an axis A and provided with a torque application surface 21 for user control. The knob 2 engages a cylindrical rotatable member 9 rotatable about an axis B parallel to the axis A. The rotatable member 9 is provided at its annular base with a coupling surface 4e, which is substantially perpendicular to the axis B of rotation of the coupling surface 4e. The rotary switch assembly 1e is provided with a rotation stop assembly 3e further comprising a coupling member 5e rotationally disposed about an axis C, substantially perpendicular to the axes A, B, on a pin 71 of a locking member 7e over a predetermined angular distance, in a manner described in detail with reference to embodiments 1a, 1 b, and 1c. The locking member 7e is movable, as indicated by an arrow, along an axis substantially parallel to the axes A, B, between an inactive position, shown in Fig. 5, and an active position in which a frictional surface 52 of the coupling member 5e is mechanically coupled with the coupling surface 4e.

In other embodiments of the present invention, not shown in detail in the drawings, a rotation stop assembly may comprise just one elastic limiting element 6 having a first end connected with a blocking element 72 and a second end connected with a blocking surface 531 or 541 and generating a progressive haptic reaction torque on a knob 2 both during compression and during expansion thereof. Furthermore directions of compression and/or expansion of elastic limiting element(s) 6 may not necessarily correspond to the angular direction of rotation of a coupling surface 4, as long as the rotation of the coupling surface 4 affect its(their) compression and/or expansion (in particular cutouts 53, 54 may not be angular). It is also possible to employ various forms of elastic limiting element(s) 6, other than coils springs, such as elastomeric cylinders or cylindrical shells, etc.

The above embodiments of the present invention are therefore merely exemplary.

The figures are not necessarily to scale and some features may be exaggerated or minimized. These and other factors however should not be considered as limiting the spirit of the invention, the intended scope of protection of which is indicated in appended claims.

List of reference numerals

A axis of rotation of the knob

B axis of rotation of the coupling surface

C axis of rotation of the coupling member

1. rotary switch assembly (1a, 1 b, 1c, 1d, 1e)

2. rotatable knob

21 . torque application surface

3. rotation stop assembly (3a, 3b, 3c, 3d, 3e)

4. coupling surface (4a, 4b, 4c, 4d, 4e)

41 . toothed rack

5. coupling member (5a, 5b, 5c, 5d, 5e)

51 . toothed cam

52. frictional surface

53. closed cutout

531 . blocking surface

54. open cutout

541 . blocking surface

6. elastic limiting element

7. locking member (7a, 7b, 7c, 7d, 7e)

71. pin

72. blocking element

73. linear toothed rack

8. toothed wheel

9. rotatable member