Steering column with angular stop for an electrically controlled vehicle steering system

Abstract

The present invention relates to a steering column assembly (20), comprising: - a steering shaft (26) rotating about its longitudinal axis (AX); - a structural element (24) locked against rotation about the longitudinal axis; - an angular locking mechanism (40) ensuring cooperation between the structural element and the steering shaft to limit the rotation of the steering shaft, comprising: - first and second internal threads (52, 54), with opposite orientations and rotationally fixed to the steering shaft; - first and second nuts (44, 46), each having an external thread (60, 62) cooperating with one of the corresponding internal threads; - means forming a slide between the nuts and the steering shaft; - means for limiting the longitudinal travel of the nuts. Figure for the abstract: Fig. 3

Description

Title of the invention: Steering column with angular stop for an electrically controlled vehicle steering system. TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to the general field of vehicle steering systems, and more particularly to a steering column for an electrically controlled steering system, also known as "Steer by Wire". TECHNICAL BACKGROUND

[0002] The steering of a moving vehicle, for example an automobile, corresponds to the set of organs enabling the direction of its trajectory to be changed while driving.

[0003] With reference to Figures 1 and 2, a steering system 1 of a vehicle generically comprises a steering column 2 connected to a steering wheel 3, and a steering rack 4 whose function is to change the orientation of a pair of wheels 5 mounted on the same axle of the vehicle, called the steering wheels, in response to the rotation of the steering wheel 3. This rack 4 consists of a threaded rod 6 which is connected to the steering wheels 5 by a system 7 of tie rods and ball joints, and a pinion 8 whose rotation induces the sliding of the threaded rod 6 parallel to the axle. Depending on the direction of rotation of the pinion 8, the threaded rod 6 slides to the left or right, thus turning the wheels in one direction or the other. In practice, the maximum angle of the steering wheels 5 is determined by the maximum permissible sliding stroke of the threaded rod 6.

[0004] Conventionally, the steering column 2 includes an intermediate shaft 9 which allows the rotation exerted on the steering wheel 3 by the user to be mechanically transferred to the nut 8 to control the wheel angle, as illustrated in [Fig. 1]. This intermediate shaft 9 is equipped with universal joints 10 at its interface ends with the steering column 2 and the steering rack 4 so as to allow a certain misalignment of the steering wheel 3.

[0005] The ongoing development of motor vehicles has recently led to a preference for electrically controlled steering of the steering wheels 5. Based on this, a "Steer by Wire" architecture has been proposed, in which the intermediate shaft 9 is replaced by an electromechanical actuator 11, as illustrated in [Fig. 2]. This electromechanical actuator 11 comprises a steering wheel rotation angle sensor 12, an electric motor 14 coupled to the pinion 8, and a control unit 15. Based on the measured steering wheel rotation angle value from the sensor 12, The control unit 15 sends a command to the electric motor 14 to rotate the pinion 8 and thus turn the wheels by the threaded rod 6 according to the user's wish.

[0006] As understood, such an electrically controlled system ensures the steering of the steerable wheels 5 based solely on a transfer of information, thus offering complete freedom in positioning the steering wheel 3 within the passenger compartment. However, the mechanical decoupling between the steering wheel 3 and the steering rack 4 allows the steering wheel to rotate indefinitely in either direction. Specifically, when the threaded rod reaches its end stop, marking the maximum steering angle in one direction, the steering wheel no longer locks, and it can continue to rotate freely in that same direction.

[0007] In practice, infinite rotation of the steering wheel is not permitted from a safety point of view because it hinders the driver's ability to assess the instantaneous orientation of the wheels, nor from a functional point of view because it could damage various elements and equipment such as, for example, electrical connectors and airbag wiring.

[0008] This situation leads to the search for solutions to give the steering column 2 a steering wheel locking capability. However, the proposed solutions are generally not used because they require lengthening the steering column, which is restrictive for its integration, and / or limits its functionality. For example, it is known that, to meet user requirements, the steering column should allow the steering wheel to move between a stowed position, away from the driver's seat, and a service position allowing for comfortable and safe handling.

[0009] The aim of the invention is thus to propose a compact arrangement of steering column which makes it possible to limit the rotation of the steering wheel without however leading to an alteration of its functionalities. Description of the invention

[0010] To this end, the invention relates to a steering column assembly for a vehicle steering system, for example of an automobile, comprising: - a steering shaft intended to carry a steering wheel of the vehicle, this steering shaft extending along a longitudinal axis and having the capacity to rotate around this longitudinal axis; - a structural element blocked from rotating around the longitudinal axis, in which the steering shaft extends at least partially; - an angular locking mechanism ensuring cooperation between the structural element and the steering shaft to limit the rotation of the steering shaft around of the longitudinal axis at a predefined angle of rotation of the steering shaft in a first direction of rotation and in a second direction of rotation, this angular locking mechanism comprising: — a first and a second internal threads centered on the longitudinal axis, of opposite orientations and offset from each other longitudinally, this first and second threads being blocked in rotation around the longitudinal axis by being carried directly or indirectly by the structural element; — a first and a second nut centered on the longitudinal axis extending radially along the longitudinal axis between the structural element and the steering shaft, these first and second nuts each comprising an external thread cooperating with one of the corresponding internal threads; — sliding means between the nuts and the steering shaft to ensure both a rotational coupling of the nuts with the steering shaft and a translational guidance of the nuts along the longitudinal axis, these sliding means jointly ensuring with the cooperation of the threads a longitudinal displacement of the nuts in response to a rotation of the steering shaft so that the nuts move away from each other in the first direction of rotation of the steering shaft and move closer to each other in the second direction of rotation of the steering shaft; — means of limiting the longitudinal travel of the nuts when they move away from and towards each other longitudinally for a predefined angle of rotation of the steering shaft in the first direction of rotation and the second direction of rotation.

[0011] The invention also relates to a steering column assembly as defined above, comprising a column body which carries the steering shaft, this column body being intended to be mounted on a vehicle structure; in which: - the steering shaft is fixed relative to the column body along the longitudinal direction; - the column body forms the structural element which cooperates with the steering shaft through the angular locking mechanism to limit a rotation of the steering shaft around the longitudinal axis.

[0012] The invention also relates to a steering column assembly as defined above, comprising a column body which carries the steering shaft, this column body being intended to be mounted on a vehicle structure; in which: - the steering shaft includes two coaxial sections, at least partially nested one inside the other, the first section being free to rotate about the longitudinal axis and fixed in longitudinal translation relative to the column body that supports it, and the second section being designed to support the vehicle's steering wheel, this second section surrounding the first section being both rotationally coupled with this first section and movable in longitudinal translation relative to this first section in a first direction of deployment and a second direction of retraction between a fully deployed shaft position, in which the steering shaft has the greatest measured longitudinal extent, and a fully retracted shaft position in which the arm has the smallest measured longitudinal extent; - the column body forms the structural element which cooperates with the first section of the steering shaft via the angular locking mechanism to limit a rotation of the steering shaft around the longitudinal axis.

[0013] The invention also relates to a steering column assembly thus defined, comprising an arm, centered on the longitudinal axis, which is carried by the column body by being at least partially fitted into a bore delimited by this column body, the arm radially surrounding the steering shaft being both blocked in rotation around the longitudinal axis and movable in translation along this longitudinal axis relative to the column body; in which the second section radially surrounds the first section; the steering column assembly being shaped so that, in the fully retracted position of the shaft, the arm extends away from a space in the bore at which the angular locking mechanism is installed.

[0014] The invention also relates to a steering column assembly defined as follows, in which: - the column body defines a bore in which the first section of the steering shaft extends at least partially; - the arm extends radially outside the bore; - the first section radially surrounds the second section; and - the angular locking mechanism is arranged in the bore.

[0015] The invention also relates to a steering column assembly defined as follows, comprising: - a column body which carries the steering shaft, this column body being designed to be mounted on a vehicle structure; - an arm, centered on the longitudinal axis, which is carried by the column body by being at least partially fitted into a bore delimited by this column body, the arm radially surrounding the steering shaft being both blocked in rotation around the longitudinal axis and movable in translation along this longitudinal axis relative to the column body; in which: - the steering shaft includes two coaxial sections, at least partially nested one inside the other, of which a first section is free in rotation around the longitudinal axis and fixed in longitudinal translation relative to the column body which carries it, and a second section which is intended to carry the steering wheel of the vehicle, this second section surrounding the first section being both coupled in rotation with this first section and movable in longitudinal translation relative to this first section in a first direction of deployment and a second direction of retraction between a deployed shaft position, in which the steering shaft has the greatest measured longitudinal extent, and a retracted shaft position in which the arm has the smallest measured longitudinal extent; - the second section of the steering shaft being fixed in longitudinal translation with the arm; - the arm forms the structural element which cooperates with the second section of the steering shaft by means of the angular locking mechanism to limit a rotation of the steering shaft around the longitudinal axis, the first and second internal threads being carried directly or indirectly by the arm.

[0016] The invention also relates to a steering column assembly defined as follows, in which: - the angular locking mechanism includes a housing centered on the longitudinal axis radially surrounding the first and second nuts, this housing extending within the structural element and being blocked in rotation by the structural element, and - the first internal thread and the second internal thread are formed on the inner surface of the housing.

[0017] The invention also relates to a steering column assembly thus defined, in which the housing is blocked in rotation by the structural element while retaining a degree of freedom in longitudinal sliding along this structural element.

[0018] The invention also relates to a steering column assembly as defined, in which the first internal thread and the second internal thread are formed directly on the structural element.

[0019] The invention also relates to a steering column assembly defined as follows, in which the means forming a slide between each nut and the steering shaft correspond to the association of at least one longitudinal groove with at least one longitudinal rib which engage with each other; in which, for each nut, one of the rib and the groove is formed by the nut while the other of the rib and the groove is carried directly or indirectly by the steering shaft.

[0020] The invention also relates to a steering column assembly defined as follows, in which the means for limiting the longitudinal travel of the nuts have two bosses which each extend longitudinally opposite a corresponding nut in the direction of removal to form directly or indirectly a longitudinal stop surface against which this nut rests.

[0021] The invention also relates to a steering column assembly thus defined, in which the bosses are formed by the housing.

[0022] The invention also relates to a steering column assembly as defined, in which the angular locking mechanism comprises rolling element stops carried by bosses against which the nuts bear in the direction of removal.

[0023] The invention also relates to a steering column assembly as defined, in which the means for limiting the longitudinal stroke of the nuts comprise a collar which separates the first internal thread and the second internal thread to form a stop for limiting the longitudinal stroke of the nuts in their direction of approach.

[0024] The invention also relates to a steering column assembly thus defined, in which the collar is formed by the housing.

[0025] The invention also relates to a steering column assembly as defined, in which each nut constitutes a means of limiting longitudinal travel for the other nut by forming a bearing surface against which the other nut butts in the direction of approach. Brief description of the drawings

[0026] Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for an understanding of which reference should be made to the accompanying drawings in which: - [Fig.l] already described is a schematic diagram of a classic steering system in which the wheels are steered by means of a mechanical coupling between the steering wheel and the steering rack; - [Fig.2] already described is a schematic diagram of an electrically controlled steering system in which the wheels are indirectly steered by an electromechanical actuator which acts on the wheels based on a measurement of the steering wheel's angle of rotation; - [Fig. 3] is a radial sectional view of a steering column comprising a fixed steering column body, a longitudinally mounted arm that is retractable within a bore in the column body, a telescopic longitudinally mounted steering shaft, in its fully extended state, which rotates about its axis by having a first fixed section in longitudinal translation and a second section fixed in longitudinal translation to the arm, and a locking mechanism angular according to an embodiment of the invention which ensures cooperation between the steering shaft and the arm to limit the rotation of the steering shaft; - [Fig.4] corresponds to the steering column of [Fig.3] in a fully retracted state of the steering shaft; - [Fig.5] is a detailed view of the angular locking mechanism equipping the steering column of figures 3 and 4, this angular locking mechanism comprising a housing carried by the arm and formed with double opposed internal threads, and two nuts carried by the steering shaft being both rotationally coupled to this shaft and able to slide along this shaft, the nuts each having an external thread cooperating with a separate thread of the housing which encapsulates them; - [Fig.6] is a cross-sectional and perspective view of the double-threaded housing isolated from the rest of the angular locking mechanism of [Fig.5]; - [Fig.7] is a perspective view of the double-threaded housing of [Fig.6], which has two longitudinal grooves on the outer surface, one of which is visible, according to an alternative embodiment; - [Fig.8] is a perspective and section view of the arm which has two longitudinal ribs on the inner surface, one of which is visible, according to an alternative embodiment, to cooperate each with a longitudinal groove formed on the outer surface of the housing in order to ensure a floating mounting of the housing in the arm. - [Fig.9] is a perspective and section view of the floating mounting of the housing of [Fig.7] in the arm of [Fig.8] by groove-rib complementarity; - [Fig. 10] is an example of a mounting protocol for the housing in the arm involving a sectoring of the arm into two parts; - [Fig. 11] is a perspective view of the two nuts isolated from the rest of the angular locking mechanism of [Fig. 5]; - [Fig. 12] corresponds to a perspective view of the two nuts carried by the second section of the steering shaft, isolated from the rest of the angular locking mechanism of [Fig.5]; - [Fig. 13] is a detailed cross-sectional view of [Fig. 12]; - [Fig. 14] corresponds to a perspective and cross-sectional view of the nuts and the housing surrounding them, isolated from the rest of the locking mechanism of [Fig. 5]; - [Fig. 15] corresponds to a partial perspective view of the steering column according to the section plane AA of [Fig.5]; - [Fig. 16a] illustrates in radial and partial section the dynamics of locking in rotation of the steering shaft in a first direction of rotation by the angular locking mechanism of [Fig.5]; - [Fig. 16b] corresponds to [Fig. 16a] in a dynamic of locking in rotation of the steering shaft following a second direction of rotation, opposite to the first direction; - [Fig. 17] is a detailed view, similar to that of [Fig.5], of the locking mechanism including a variant embodiment of the housing and ball stops; - [Fig. 18] illustrates an arrangement in which the steering column includes a force feedback module; - [Fig. 19a] is a radial section view of the steering column of figures 3 and 4 in a fully deployed state of the steering shaft, in which the angular locking mechanism cooperates with the column body and the first section of the steering shaft which is fixed in longitudinal translation, according to a variant of the positioning of this locking mechanism; - [Fig. 19b] corresponds to the steering column of [Fig. 19a] in a fully retracted state of the steering shaft; - [Fig.20a] is a radial section view of an alternative embodiment of the steering column in a fully deployed state of the steering shaft, in which the column body extends radially between the first section of the steering shaft and the retractable arm, and in which the locking mechanism cooperates with the column body and the first section of the steering shaft; - [Fig.20b] corresponds to the steering column of [Fig.20a] in a fully retracted state of the steering shaft; - [Fig.21] is a radial section view of an alternative embodiment of the steering column which is without arms and whose steering shaft is not telescopic by extending into the column body, and in which the locking mechanism cooperates with the column body and the steering shaft. DETAILED DESCRIPTION OF THE INVENTION

[0027] Throughout the following description, the elements will be defined on the basis of a longitudinal direction and a radial direction. The longitudinal direction corresponds to the direction defined along an axis AX. The radial direction, defined by an axis AY, is at every point a direction orthogonal to the axis AX and passing through it.

[0028] Also, an element is said to be radially "external" or "outer" relative to another if it is further from the AX axis than the other, and conversely, an element is said to be radially "inner" or "inner" if it is closer to the AX axis than the other. Similarly, an element oriented radially "outward" moves away from the AX axis, while an element oriented radially "inward" moves toward the AX axis.

[0029] With reference to [Fig.3], a steering column 20 according to the invention is shown for a vehicle steering system of the "Steer by Wire" type, namely electrically controlled in accordance with the architecture shown in [Fig.2].

[0030] The steering column 20 comprises a column body 22 intended to be carried by a vehicle frame, namely an element of the superstructure of a vehicle, an arm 24 which is carried by the column body 22 and a steering shaft 26 which is intended to carry a steering wheel of the vehicle, not shown.

[0031] The steering shaft 26 extends along a longitudinally oriented axis AX. The arm 24, also longitudinally extended, is generally in the form of a tube centered on the axis AX and radially surrounding the steering shaft 26. This arm 24 is longitudinally delimited by a distal end 24a and a proximal end 24b, the distal end 24a being defined as being longitudinally further from the steering wheel than the proximal end 24b.

[0032] The steering shaft 26 is designed to be rotationally connected to the vehicle's steering wheel. In the example shown in [Fig. 3], this steering shaft 26 has a free end 28 that extends longitudinally from the arm 24 to receive the vehicle's steering wheel by means of a press fit. It should be noted, however, that the invention is not limited to a rigid coupling of the steering wheel to the steering shaft 26, and allows for indirect coupling of these elements, for example via a reduction gear at their interface.

[0033] In the context of the invention, the steering column 20 is intended to allow longitudinal movement of the steering wheel within the passenger compartment of the vehicle equipped with it. To this end, the arm 24 is retractable relative to the column body 22, and additionally, the steering shaft 26 includes a section mounted in a linear motion to the arm 24.

[0034] In more detail, the column body 22 has a bore 23 in which the arm 24 is mounted to allow longitudinal sliding while being prevented from rotating. It should be noted that friction systems can be installed at the interface between the column body 22 and the arm 24 to ensure a certain axial and radial stiffness. Additionally, the steering shaft 26 is telescopic, consisting of a coaxial first section 30 and second section 32.

[0035] As understood, the arm 24 and the column body 22 are configured to allow relative movement along the longitudinal direction, which in practice corresponds to a movement of the shaft 24, and therefore of the steering wheel, relative to the column body 22 once the latter is mounted on the vehicle frame. It should be noted that the column body 22 can be pivotally mounted relative to the vehicle frame, around a pivot axis, to further allow height adjustment of the steering wheel in the passenger compartment. In such a case, the column body 22 always retains a longitudinal connection to the frame.

[0036] The first section 30 of the steering shaft 26 is generally in the form of a tube or a solid shaft which is longitudinally delimited by an end distal 30a and a proximal end 30b, the distal end 30a being defined as being longitudinally further from the flywheel than the proximal end 30b. In particular, this first section 30 is supported by the column body 22, being both blocked in translation relative to this column body 22 and free to rotate about the axis AX on which it is centered, notably by means of a rotational guide bearing 32.

[0037] The second section 32 also has the general form of a tube, being delimited by a distal end 32a and a proximal end corresponding to the free end 28 of the steering shaft 26. This second section 32 extends radially around the first section 30, being supported by the arm 24 by means of at least one bearing, designated by 34. This bearing 34 allows the rotation of the second section 32 around the axis AX while making the second section 32 fixed in translation to the arm 24.

[0038] External grooves 36 project from the outer periphery of the first section 30, oriented radially outwards, and internal grooves 38 project from the inner periphery of the second section 32, oriented radially inwards. These grooves 36 and 38 extend longitudinally opposite each other, shaped to engage directly with one another as in the example shown in the figures, or to cooperate indirectly via an interfacing element. By way of non-limiting example, it may be advisable to form an interfacing element by plastic injection molding on the first section 30 to ensure a connection with the second section 32 with low sliding force while providing high torsional stiffness.

[0039] With this arrangement, the first and second sections 30, 32 are thus coupled in rotation around the axis AX while allowing a relative longitudinal displacement.

[0040] In practice, the first section 30 of the steering shaft 26 being mounted fixed in translation in the column body 22, it is understood that only the longitudinal displacement of the second section 32 along the first section 30 is permitted.

[0041] In view of the above, the steering shaft 26 is jointly supported by the column body 22 by means of the first section 30 and by the arm 24 via the second section 32, which ensures overall cohesion by engaging the sections 30, 32 with each other.

[0042] Given that the second section 32 both carries the steering wheel and is fixed in longitudinal translation with the arm 24, this arm 24 acts in practice like a muscle: its sliding in the bore 23 of the column body 22 leads to the displacement of the second section 32 of the steering shaft 26 relative to the first section 30 and, consequently, to the displacement of the steering wheel.

[0043] Considering the steering column 20 installed in the vehicle, namely with the column body 22 fixed and the arm 24 extending from the column body 22 towards a driver's seat, then: - the sliding of the arm 24 in a direction noted SI relative to the column body 22, induces the movement of the steering wheel towards the driver's seat by means of the deployment of the steering shaft 26, the second section 32 moving away from the distal end 30a of the first section 30; and consequently - the sliding of the arm 24 relative to the column body 22 in the opposite direction to SI, noted S2, leads to the steering wheel being moved away from the driver's seat by retraction of the steering shaft 26, it being understood that the second section 32 covers more of the first section 30 as it moves towards the distal end 30a of this first section 30.

[0044] Overall, the longitudinal extent of the steering shaft 26 is adjustable between a fully retracted state, denoted R at the free end 28 of the shaft 26 in [Fig. 3], and a fully extended state, denoted D at the free end 28 of the shaft 26 in [Fig. 4]. Advantageously, the fully retracted state of the steering shaft 26 corresponds to a stowed position of the steering wheel, which can be adopted, for example, for comfort purposes in a vehicle driving situation that does not require manual steering control, namely in autonomous driving situations, or when the vehicle is stationary to facilitate the driver's entry into the passenger compartment. The steering shaft 26 can also adopt the fully retracted state R in a vehicle crash situation.

[0045] The fully extended state of the steering shaft 26 corresponds to the steering wheel being positioned closest to the driver's seat. It should be noted that the steering shaft 26 can be partially retracted to adjust the steering wheel position as needed within the passenger compartment to ensure a comfortable and safe grip for the driver.

[0046] The invention is not limited to the means used to longitudinally move the arm 24 to ensure the longitudinal movement of the second section 32 relative to the first section 30, namely, to ensure the longitudinal movement of the steering wheel. In practice, the movement of the arm 24 can be achieved by manual intervention by the driver or by electromechanical actuation, for example, by means of a screw-nut system in which the screw is driven in rotation by an electric motor to move the nut fixed to the arm 24.

[0047] In the example shown in the figures, the fully retracted position of the steering shaft 26 is defined by the longitudinal abutment of the distal end 24a of the arm 24 against a shoulder, designated by 39, formed by the column body 22. However, the invention is not limited to this feature. By way of non-limiting example, the fully retracted position of the steering shaft 26 may be marked by a longitudinal stop of the second section against a stop surface formed on the column body 22, on the first section 30, or on the screw-nut system whose screw is driven in rotation by an electric motor as described above.

[0048] The idea behind the invention lies in incrementally increasing the rotation-locking function of the steering shaft 26 for a "Steer by Wire" application of the column 20 without altering the steering wheel position adjustment function as described. In other words, the rotation-locking function of the steering shaft 26 is intended to be compatible with sliding by the arm 24 of the second section 32 of the steering shaft 26 along the first section 30 over the entire sliding range determined solely on the basis of the steering wheel movement requirements. As understood, the rotation-locking function of the steering shaft 26 is therefore intended to be neutral within the scope of the invention with respect to the steering wheel movement function.

[0049] In this regard, the steering column 20 includes an angular locking mechanism 40 specifically adapted to this functional constraint.

[0050] In practice, blocking the rotation of the transmission shaft 26 is structurally challenging when it is necessary to avoid hindering the sliding of the second section 32 along the first section 30. The idea behind the invention lies in the advantageous use of a screw-nut type motion converter that allows the rotation of the transmission shaft 26 to be converted into a translational motion. With this solution, it becomes possible to block the rotation of the transmission shaft 26 by blocking the translational motion.

[0051] According to a specific arrangement described on the basis of figures 3 to 16b, the angular locking mechanism 40 is in the form of the association of a housing 42 and a pair of nuts 44, 46.

[0052] The housing 42 is generally in the form of a longitudinal tube of revolution which is centered on the axis AX. This housing 42 extends radially between the arm 24 and the second section 32 of the steering shaft 26.

[0053] In particular, this housing 42 is delimited longitudinally by a distal end 42a and a proximal end 42b at each of which a boss 50a, 50b is formed. These bosses 50a, 50b protrude radially inwards, namely extend radially towards the transmission shaft 26, without however coming into contact with it so as not to generate friction.

[0054] The housing 42 is radially delimited between the distal end 42a and proximal end 42b by an inner surface at the level of which are formed a first internal thread 52 and a second internal thread 54. According to a major feature of the invention, these internal threads 52, 54 have opposite orientations.

[0055] The internal threads 52, 54, also commonly called tapped holes, are each formed between the middle part of the housing 42, denoted 42c in [Fig. 6], and one of the corresponding bosses 50a, 50b. In detail: - the first internal thread 52 protrudes from the inner surface of the housing 42, extending longitudinally from the boss 50a formed at the distal end 42a towards the median region 42c; and complementaryly - the second internal thread 54 protrudes from the inner surface of the housing 42 by extending longitudinally from the boss 50b formed at the proximal end 42b towards the median region 42c.

[0056] In addition, the housing 42 advantageously includes a collar 56 formed in the median region 42c, which separates the first internal thread 52 from the second internal thread 54. This collar protrudes from the inner surface of the housing 42 by extending radially towards the steering shaft 26 without coming into contact with it so as not to generate friction.

[0057] From a dimensional point of view, it is advantageously recommended that the longitudinal extent measured between the collar 56 and the boss 50a formed at the distal end 42a be exactly the same as that measured between this collar 56 and the boss 50b formed at the proximal end 42b. More specifically, the threads 52, 54 are shaped to have exactly equal longitudinal extents, each extending from the corresponding boss 50a, 50b of the housing 42 to the collar 56.

[0058] The housing 42 is supported by the arm 24 which surrounds it and is carried with it in translation during the adjustment of the steering wheel position, in an overall movement. According to a major feature of the invention, the housing 42 is also installed fixed in rotation relative to the longitudinal axis AX.

[0059] In detail, the housing 42 can either be rigidly supported by the arm 24 which is fixed in rotation, or advantageously be floating supported by this arm 24, namely by granting it a limited capacity for possible longitudinal movement relative to this arm 24 while preventing it from rotating.

[0060] Such a floating assembly allows the housing 42 to move relative to the arm 24 over a certain distance which remains significantly less than the maximum sliding stroke of the arm 24 relative to the column body 22 between the fully retracted R and deployed D states of the steering shaft 26.

[0061] With reference to figures 7 and 8, the floating mounting of the housing 42 in the arm 24 can be ensured by means of the formation of at least one groove-rib pair, of which: - a longitudinal rib 58 provided on the inner periphery of the arm 24; - a longitudinal groove 60 provided on the outer periphery of the casing 42, in which the rib 58 of the arm 24 is housed. Note that the reverse arrangement can also be used.

[0062] The rib 58 is dimensioned with a length denoted 1, measured longitudinally, shorter than the length L of the corresponding groove 60, so that the housing 42 is allowed to move relative to the arm 24 over a distance corresponding to the difference in length.

[0063] In the example of figures 9 and 10, two pairs {rib 58 - groove 60} are provided diametrically opposed, but the invention is not limited to a particular number.

[0064] To allow the installation of the housing 42 in the arm 24, it is suggested to form the arm 24 by assembling several angular sectors around the housing 42 so as to be able to fit each rib 58 into the corresponding groove 60. As an example, in the case of two pairs [rib 58 - groove 60], the arm 24 can be formed by the assembly of two semi-cylindrical sections 24' and 24”, each comprising a rib 58 which engages in a corresponding groove 60 of the housing 42, as schematically shown in [Fig. 10].

[0065] It should be noted that an arrangement can be used in which only one pair of groove-rib is formed, namely a single groove 60 formed at the level of the housing 42 and a single rib 58 formed at the level of the arm 24, thus avoiding splitting the arm 24 into several sections to allow assembly.

[0066] In the example of [Fig.8], the rib 58 corresponds to an excess thickness of material, directly formed with the arm 24. Alternatively, the rib 58 can be replaced by a lug assembled to the arm 24. This solution eliminates the need for sectoring the arm 24 by assembling the lug to the arm 24 after the housing 42 has been positioned within the arm 24. For example, the housing 42 can be positioned within the arm 24, and then a rod can be inserted from the outside through the thickness of the arm 24, aligned with the groove 60 of the housing 42, to form the lug protruding internally from the arm 24. This rod can, in particular, take the form of a countersunk screw that is countersunk within the thickness of the arm 24.

[0067] As understood, the invention is not limited to a particular conformation of the housing 42 and the arm 24 to ensure a floating mounting of the housing 42. The formation of a one-piece rib 58 with the arm 24 or the assembly of a lug are non-limiting examples of arrangements that may be retained depending on the final choice of the assembly range of the complete system.

[0068] Another rotational guide bearing for the second section 32, relative to the arm 24, designated by 55, can optionally be arranged between the distal end 42a of the housing 42 and the distal end 24a of the arm 24, so as to ensure the axial stability of the housing 42 in conjunction with the bearing 34. This bearing 55 is positioned at a distance from the casing 42 so as not to impede its longitudinal movement relative to the arm 24 within the framework of the floating assembly described.

[0069] As regards the nuts 44 and 46, they are each intended to be installed centered on the longitudinal axis AX by extending radially between the housing 42 and the steering shaft 26. In the example of Figures 3 to 16b, the nuts 44 and 46 are carried by the second section 32 of the steering shaft 26. They will be described thereafter in relation to this particular destination location.

[0070] The first nut 44 has an external thread 60, formed on its outer surface opposite the housing 42, which engages the first internal thread 52 of the housing 42 surrounding it. Similarly, the second nut 46 has an external thread 62 which engages the second internal thread 54 of the housing 42. Note that the external threads 60, 62 of the nuts 44, 46 have opposite orientations to conform to the thread 52, 54 with which they cooperate. The engagement of the external threads 60, 61 of the nuts 44, 46 in the internal threads 52, 54 is illustrated in detail in [Fig. 11].

[0071] In addition to the cooperation between the external threads 60, 62 of the nuts 44, 46 and the internal threads 52, 54 of the housing 42, the invention aims to ensure rotational coupling of these nuts 44, 46 with the steering shaft 26 while allowing their translation along the longitudinal axis AX. In this regard, it is advantageously recommended to form a sliding joint between the nuts 44, 46 and the second section 32 of the steering shaft 26 which carries them. In the example of Figures 11-15, this sliding joint is achieved by forming: - of internal ribs 64, 66, designated as grooves, extending longitudinally on the inner surface of the nuts 44, 46; and - - of grooves 68 extending longitudinally along the outer peripheral surface of the second section 32, in which the internal grooves 64, 66 of the nuts 44, 46 engage in a sliding fit.

[0072] In particular, each longitudinal groove 68 of the second section 32 accommodates a set of two grooves, including an internal longitudinal groove 64 of the first nut 44 and an internal longitudinal groove 66 of the second nut 46, which judiciously have the same cross-sectional profile corresponding substantially to the negative of the groove profile.

[0073] In the example of [Fig. 15], which illustrates a sectional view along the cutting plane AA of [Fig. 5], eighteen pairs of {splint 66 - groove 68} extending circumferentially at regular intervals can be distinguished. It should be noted, however, that in practice, a single rib-groove pair is sufficient to create the sliding joint ensuring the rotational coupling of the nuts 44, 46 with the second section 32 of the steering shaft 26 while allowing them to translate along this second section 32.

[0074] Also, however, an inverse arrangement may be retained, namely in which at least one longitudinal groove is formed on the outer surface of the nuts 44, 46 to cooperate with a longitudinal rib formed on the outer periphery of the second section 32.

[0075] It should also be noted that the invention is not limited to this particular sliding joint arrangement based on a rib-groove complementarity. In practice, such a sliding joint can be obtained by means of any complementary shape in non-circular sections between the inner surface of the nuts 44, 46 and the outer surface of the second section 32 of the steering shaft 26.

[0076] In practice, allowing the nuts 44, 46 to slide along the second section 32 of the steering shaft 26 is a functional constraint. Indeed, given that the nuts 44, 46 are rotationally coupled with the steering shaft 26 and that the external threads 60, 62 of these nuts 44, 46 mesh with the internal threads 52, 54 of the housing 42, which is rotationally fixed, rotation of the steering shaft 26 is permitted if and only if the nuts 44, 46 can translate longitudinally in response. In other words, the rotation of the steering wheel, carried by the steering shaft 26, is conditioned by the ability of the nuts 44, 46 to move longitudinally in the housing 46 by screwing / unscrewing each along the internal thread 52, 54 with which it cooperates.

[0077] In the case of a floating mounting of the housing 42 on the arm 24, it is further advantageously recommended to allow longitudinal translation of the housing 42 relative to the arm 24 only in response to a longitudinal force exerted on the housing 42 that is significantly higher than in the case of handwheel adjustment. By way of example, with reference to the floating mounting described based on Figures 7 to 9, this characteristic can be ensured by equipping the rib 58 with two elastic load elements on either side, which passively prevent it from sliding longitudinally in the groove 60.

[0078] As a result, the housing 42, and more generally the angular locking mechanism 40, is ensured to slide with the arm 24 in a coordinated movement during normal steering wheel adjustment. It should be noted that, in practice, the force exerted on the housing 42 during steering wheel adjustment relates to the friction of the nuts 44, 46 against the steering shaft 26.

[0079] It should also be noted that counteracting the unexpected movement of the housing 42 relative to the arm 24 in the case of such a floating assembly also stems from a comfort requirement. Since the acoustic and vibrational environments within the passenger compartment have become particularly refined in response to user demands, this is, in practice, a matter of to prevent the rib 58 from freely oscillating in the groove 60 against the walls during vibration, for example when driving the vehicle on cobblestones. Such an interaction could be accompanied by an audible noise, potentially leading the user to believe that the steering column is defective and therefore that vehicle safety is compromised.

[0080] To allow both the installation of the nuts 44, 46 around the second section 32 of the steering shaft 26 and the engagement of the external threads 60, 62 of the nuts 44, 46 with the internal threads 52, 54 of the housing 42, the housing 42 can be formed by assembling several angular segments. In practice, this involves installing the nuts 44, 46 on the second section 32, before assembling the angular segments of the housing 42 around the nuts 44, 46 to encapsulate them.

[0081] Alternatively, it may be recommended to mount the nuts 44, 46 in the housing 42, then to install this assembly on the second section 32 of the steering shaft 26 before positioning the arm 24 around it.

[0082] In the example shown in the figures, the internal threads 52, 54 of the housing 42 are identical, particularly with regard to the thread pitch P, except for their opposite orientations. Thus, it is understood that for a given angle of rotation 0 of the nuts 44, 46, for example over one revolution, they move longitudinally along the corresponding internal thread 52, 54 of the housing 42 over the same distance X according to the conventional screw-nut relationship: X = y - 0 -

[0083] With reference to figures 16a and 16b, the actuation kinematics of the angular locking mechanism 40 will be described.

[0084] In a first case, a rotation of the transmission shaft 26 in a first direction denoted RI is permitted if the nuts 44, 46 can also rotate in the same direction, it being understood that they are rotationally coupled with the second section 32. Now, given that the nuts 44, 46 also cooperate by threads with the housing 42 which surrounds them, their rotation is possible provided that they can simultaneously translate along the second section 32 of the transmission shaft 26. As a result, the rotation of the transmission shaft 26 in the first direction RI is permitted as long as sliding of each of the nuts 44, 46 along the longitudinal axis AX is allowed.

[0085] Due to the opposite orientation of the threads 52, 54 of the housing 42, the nuts 44, 46 are caused to slide longitudinally away from each other in response to the rotation of the transmission shaft 26 in this first direction RI. The first nut 44 is thus caused to translate in the direction S2 towards the distal end 42a of the housing 42, while the second nut 46 is caused to simultaneously translate in the direction SI towards the proximal end 42b of the housing 42.

[0086] Along its longitudinal travel along the second section 32 towards the distal end 42a of the housing 42, in the direction S2, the first nut 44 eventually encounters the boss 50a, which forms a longitudinal stop surface. Similarly, the second nut 46, along its travel in the direction S1, eventually encounters the boss 50b of the housing 42, which also forms a longitudinal stop surface. As can be understood, these bosses 50a and 50b are arranged so as to each form an obstacle along the travel of the nuts 44 and 46 as they move away from the central region 42c of the housing 42.

[0087] Once the nuts 44, 46 are each longitudinally supported against the corresponding boss 50a, 50b of the housing 42, as illustrated in [Fig. 16a], their translation is blocked. This translational blockage results in a blockage of the rotation of the steering shaft 26 in the RI direction, since the rotation of the nuts 44, 46 in this same RI direction is no longer permitted because they cannot slide longitudinally. In other words, the rotation of the steering shaft 26 in the RI direction can no longer continue, as it is contingent upon the free translation of all the nuts 44, 46 by screwing them into the housing 42. Since the steering shaft 26 is thus blocked at this stage from rotating in the RI direction, the steering wheel is consequently blocked in this direction of rotation.

[0088] In practice, the longitudinal translation of the nuts 44, 46 becomes a longitudinal force rising against the housing 42 once they have come into contact with it: the first nut 44 develops a clamping force F44 oriented in the direction S2 while the second nut 46 develops a clamping force F46 oriented in the direction SI, opposite to the direction S2.

[0089] These forces F44, F46 of opposite orientations compensate each other so that overall the blocking in rotation in the direction RI of the steering shaft 26 by the angular locking mechanism 40 according to the invention does not generate longitudinal force on the structural parts, in particular on the arm 24 and this steering shaft 26, and the bearings 34, 55.

[0090] This force compensation feature is ensured in particular by the floating mounting of the housing 42 on the arm 24. Indeed, even though during assembly it is recommended to install the nuts 44, 46 in the housing 42 in a mirror arrangement, that is to say, each at an equal distance from the boss 50a, 50b directly opposite it, a very slight misalignment may occur in practice. In such a case, it is understood that one of the nuts 44, 46 will come to rest against the corresponding boss 50a, 50b while the other extends some distance from it. However, the rotation of the steering shaft 26 in the RI direction is not blocked because the housing 42 can translate longitudinally by screwing itself in reaction to the nut that has reached its stop, thus allowing the other nut to continue its translational movement until it encounters the housing 42. Once the offset is compensated, that is, once the two nuts 44, 46 In longitudinal support against the bosses 50a, 50b of the casing 42, there follows a generation of opposing longitudinal forces F44, F46 which cancel each other out.

[0091] By way of example, assuming that the first nut 44 comes to rest against the boss 50a of the housing 42, while the second nut 46 has not yet reached the boss 50b, the steering shaft 26 continues to rotate along RI by means of a translation of the housing 42 in the direction S2 imposed as a reaction by the first nut 44. As the rotation of the steering shaft 26 continues despite the first nut 44 reaching its abutment against the boss 50a, the second nut 46 continues its movement along the second section 32 towards the corresponding boss 50b of the housing 42. It should be noted that the translation of the housing 42 along S2 is equivalent to a movement along SI of the second nut 46, thus facilitating the compensation of the offset. When the second nut 46 comes into effective contact with the boss 50b, the steering shaft 26 is blocked from rotation according to RI.

[0092] The actuation dynamics explained with reference to [Fig. 16a] in the direction of rotation RI of the steering shaft 26 follows the reverse logic in a second case marked by the rotation of the transmission shaft 26 in a second direction noted R2, opposite to the direction RL. In the context of this second case, the first nut 44 thus translates in the direction SI towards the median region 42c of the housing 42 and, simultaneously, the second nut 46 translates in the direction S2 also towards the median region 42c of the housing 42.

[0093] Along their longitudinal course towards the median region 42c, these first and second nuts 44, 46 eventually meet the collar 56 which forms a longitudinal stop surface for both.

[0094] Once the nuts 44, 46 are each pressed against the collar 56, as illustrated in [Fig. 16b], their translation is blocked. This translational blockage of the nuts 44, 46 then results in a blockage of the rotation of the steering shaft 26 in the R2 direction. Since the steering shaft 26 is thus blocked at this stage from rotating in the R2 direction, the steering wheel carried by the steering shaft 26 is consequently blocked in this same R2 direction of rotation.

[0095] In the same way as in the first case of rotation about RI of the steering shaft 26, the longitudinal translation of the nuts 44, 46 moves in a longitudinal upward force against the collar 56 once they reach contact with it. The clamping force F44 developed by the first nut 44 is oriented in the direction S1 while the clamping force F46 exerted by the second nut 44 is oriented in the direction S2.

[0096] The opposing forces F44 and F46 cancel each other out so that overall the rotational blocking in direction R2 of the steering shaft 26 by the mechanism of angular locking 40 according to the invention does not generate longitudinal force on the structural parts.

[0097] Also, in a manner analogous to the first case, the floating mounting of the housing 42 to the arm 24 guarantees this compensation of the forces F44, F46 despite the existence of an offset inducing one of the nuts 44, 46 to come into contact with the collar 56 before the other.

[0098] By way of example, assuming that only the first nut 44 comes into contact with the collar 56, the steering shaft 26 continues to rotate along R2 by means of the pure translation of the housing in the SI direction by screwing onto the first nut 44. The rotation of the rod 42 continues despite the first nut 44 coming into contact with the collar 56, the second nut 46 continues its movement along the rod 42 towards this collar 56. As soon as the second nut 46 comes into effective contact with the collar 56, the steering shaft 26 is blocked from rotating along R2 due to the lack of sliding of the nuts 44, 46.

[0099] In view of the above, the rotation of the steering wheel is thus limited in one direction of rotation as in the other by a translational locking of the nuts 44, 46 along the second section 32 of the steering shaft 26.

[0100] Even if the use of a single movable nut between two stops along a housing with a single internal thread would also be functional to limit the rotation of the steering shaft 26, the longitudinal forces generated by the nut when it comes to rest against the stops would not be compensated in any way, which would negatively affect the steering column 20. By using the two nuts 44, 46 and the housing with opposing double threads 52, 54 according to the invention, such a generation of longitudinal stresses is avoided.

[0101] Converting the rotation of the steering shaft 26 into a translation of the nuts 44, 46 according to the invention allows for considerable flexibility in defining the maximum angular travel desired for the steering wheel. In practice, the maximum angular travel of the steering shaft 26 is a function of the linear travel of the nuts 44, 46 along the longitudinal direction permitted between their abutments. Based on this, it is possible to adjust the length, pitch, or number of threads of the threads 52, 54 of the housing 42 and the nuts 44, 46, or the length of the collar 56 and the bosses 50a, 50b, to achieve a given maximum angular value of rotation. Without limitation, it is recommended according to the invention to fix this maximum angular value of rotation of the steering shaft 26 at approximately 720 degrees on either side of the neutral position of the steering wheel.This value corresponds to four turns of the steering wheel from a first locking of the nuts 44, 46 marking the position of steering the vehicle's wheels to the right until a . second locking of nuts 44, 46 marking the steering position of the vehicle's wheels to the left.

[0102] The housing 42 has been described as comprising a collar 56 which the nuts 44, 46 eventually contact after a certain degree of rotation along R2 of the steering shaft 26. It should be noted that the angular locking mechanism 40 is not limited to this feature. Indeed, an alternative arrangement without a collar 56, as illustrated in [Fig. 17], can be used, in which the nuts 44, 46 bear against each other to block the rotation of the steering shaft 26 in the direction R2. This alternative embodiment of the angular locking mechanism suggests, but does not necessarily imply, depending on the morphology of the nuts, that the internal threads 52, 54 of the housing 42 meet in the mid-region 42c. As understood, the nuts 44, 46 are suitable to each form a means of limiting longitudinal travel for the other when they approach in response to the rotation of the steering shaft 26 along the second direction of rotation R2.

[0103] Also, the locking of the steering shaft 26 in the first direction of rotation RI has been explained as the result of the direct support of the nuts 44, 46 against the bosses 50a, 50b of the housing 42. It should be noted that this support can be achieved indirectly by interposing an interface element between each nut-boss pair.

[0104] As an example, it may be advisable to mount a sound-absorbing element on each boss 50a, 50b, against which the nut 44, 46 bears, in order to improve the acoustic environment. Indeed, the contact and increased force exerted by the nuts 44, 46 directly against the housing 42 can be accompanied by an audible noise which may give the user the impression that the steering system is defective and therefore that the vehicle's safety is not ensured.

[0105] Also, it may be recommended within the framework of the invention to install rolling element thrust bearings, such as ball / needle thrust bearings or bearings, as an interface between the housing 42 and the nuts 44, 46. As illustrated in [Fig.17], a pair of ball thrust bearings 74 are mounted on the housing 42, each at the level of a distinct boss 50a, 50b, to form the bearing surfaces of the nuts 44, 46 in the case of rotation of the steering shaft 26 in the first direction RI of rotation.

[0106] From a kinematic point of view, when the nuts 44, 46 tighten onto the bosses 50a, 50b, they tend to rotate the housing 42, generating a rotational torque on it. This rotational torque is transmitted to the arm 24, which holds the housing 42 in place.

[0107] The integration of such ball bearings 74 makes it possible to limit the coefficient of friction, resulting in a significantly lower transfer of rotational torque. Therefore, this avoids the need to oversize the means for locking the housing 42 against rotation. by the arm 24, and the means of locking the arm 24 in rotation relative to the column body 22; along which the forces pass.

[0108] The locking mechanism 40 has been described based on Figures 3 to 17 as comprising a housing 42 carried by the arm 24, enclosing the two nuts 44, 46 which are carried by the second section 32 of the steering shaft 26. Since the arm 24 and the second section 32 are fixed in longitudinal translation, it follows that the mechanism 40 follows the joint translation of these elements in a unified movement when adjusting the steering wheel position. Thus, the mechanism 40 integrates perfectly with the steering column 20 of the example in [Figs. 3] and 4 to limit the rotation of the steering shaft 26 without in any way altering the extension / retraction capacity of this steering shaft 26.

[0109] In practice, the steering column 20 can be equipped with a force feedback module 75, also called a "Force Feedback Unit" or "FFU". This force feedback module 75 provides the driver with force feedback giving sensations similar to those perceived with conventional mechanical steering.

[0110] In the example of [Fig. 18], the force return module 75 is advantageously fitted to the first section 30 for reasons of available space with regard to the locking mechanism 40 cooperating with the second section 32. It should be noted however that any other destination location of the force return module 75 can be envisaged within the framework of the invention.

[0111] It should be noted that the invention is not limited to the destination location of the locking mechanism 40 in the steering column 20 as described on the basis of Figures 3 to 18.

[0112] In concrete terms, the angular locking mechanism 40 according to the invention makes it possible to limit the rotation of the steering shaft 26 by means of cooperation between the steering shaft 26 and any other structural element of the steering column 20 which meets the following criteria: - this element is blocked from rotating around the longitudinal axis AX; - this element extends radially opposite the steering shaft 26, or opposite a particular section of the steering shaft 26; and - has no translational movement relative to the steering shaft 26, or this section of steering shaft, along the longitudinal direction.

[0113] It should be noted that in the case of a floating mounting of the housing 42, the aforementioned structural element may correspond to a part capable of slightly translating the steering shaft 26 relative to the fact that this small displacement can be compensated for by the translation of the housing 42. As will be understood, in addition to being able to compensate for a misalignment of the nuts 44, 46, this floating mounting of the housing to the structural element can also make it possible to compensate for a small translational displacement longitudinal of this structural element with respect to the steering shaft 26, or the corresponding steering shaft section.

[0114] In the example of Figures 3 to 18, the locking mechanism 40 cooperates with the arm 24 and the second section 32 of the steering shaft 26, which move longitudinally in a unified motion during steering wheel position adjustment. Based on this, it is clear that the arm 24 and the second section 32 do not have relative movement along the longitudinal direction; in other words, they share the same longitudinal reference frame during steering wheel position adjustment.

[0115] According to another possible arrangement of the locking module 40 within the steering column 20 as described on the basis of [Fig. 3] and 4, it can be installed to cooperate with the first section 30 of the steering shaft 26 and the column body 22. Indeed, since the first section 30 is mounted fixed in translation relative to the column body 22, these two elements have no relative movement in the longitudinal direction, so they are compatible to cooperate together via the locking mechanism 40 in order to limit the rotation of the steering shaft 26. In this respect, according to an alternative embodiment illustrated in Figures 19a and 19b, the locking mechanism 40 has the same architecture as that described on the basis of Figures 5 to 15, with the difference that: - the nuts 44, 46 extend radially around the first section 30 which carries them, being rotationally fixed to it while retaining a sliding capacity along this first section 30; - the housing 42 is supported by the column body 22, extending into the bore 23.

[0116] In a manner analogous to the case described on the basis of Figures 3 to 15, the housing 42 is advantageously mounted floating on the column body 22 to maintain a degree of freedom in translation and thus satisfy a compensatory bearing of the nuts 44, 46 against the bosses 50a, 50b and the collar 56. As described on the basis of Figures 7 to 10, this floating mounting can be achieved by means of cooperation between at least one longitudinal groove 60 formed on the outer surface of the housing 42 and at least one longitudinal rib 58 formed on the column body 22.

[0117] Given that the column body 22 and the first section 30 of the steering shaft 26 are fixed in translation, it is understood that the locking mechanism 40 remains in the same position regardless of the retraction / extension state of the steering shaft 26. This embodiment requires that the locking mechanism 40 not be positioned along the translational travel of the second section 30 and the arm 24, otherwise it would obstruct the retraction of the steering shaft 26. In practice, this implies that the first section must have sufficient longitudinal length to define a space, denoted H in [Fig. 19b], large enough to accommodate the locking mechanism 40 within the bore 23 when the steering shaft 26 is in the fully retracted state. As is understood, this space H is never reached by the arm 24.

[0118] It should also be noted that the locking mechanism 40 according to the invention is not strictly limited to equipping the steering column 20 as described on the basis of Figures 3 and 4.

[0119] As illustrated in Figures 20a and 20b, the locking mechanism 40 can also incorporate a steering column 20 of which: - the column body 22 extends radially between the steering shaft 26 and the arm 24; and - the second section 32 extends into the first section 30 which surrounds it, according to an arrangement of the steering shaft 26 which is reversed to that of the example in figures 3 and 4.

[0120] In this other variant of figures 20a and 20b, the locking mechanism 40 is presented in the same way as in that illustrated in figures 19a and 19b, with: - the nuts 44, 46 which extend radially around the first section 30 which carries them, being rotationally fixed with it while retaining a sliding capacity along this first section 30; - the housing 42 is supported by the column body 22, extending into the bore 23.

[0121] Since the arm 24 extends radially outside the column body 22 and the first section 30 of the steering shaft 26 extends opposite the column body 22 in the variant of Figures 20a and 20b, it is understood that the locking mechanism 40 cannot hinder the sliding of the arm 24 during the steering wheel position adjustment, i.e. regardless of the actual position of the arm 24 between the fully deployed and retracted states of the steering shaft 26. In other words, knowing that the locking mechanism 40 is not radially aligned with the arm 24, it never forms an obstacle for the latter. It follows that this variant of the steering column embodiment can be formed more compactly along the longitudinal direction than the previous variant, described on the basis of Figures 19a and 19b, which is subject to a dimensioning constraint of the first section 30 to delimit the integration space H of the locking mechanism 40..

[0122] Also, it should be noted that the angular locking mechanism 40 is not necessarily required to be fitted to a steering column whose steering shaft 26 is telescopic, namely with the capacity to deploy and retract by sliding one section over another.

[0123] In practice, the angular locking mechanism 40 also finds application for a steering column whose steering shaft 26 is a single unit, namely, one that is not formed of several sections that can be moved relatively in the longitudinal direction. A steering shaft 26 is considered a single unit if it is formed of a single section, or of several sections 30, 32 not having relative translational capacity. For example, the telescopic steering shaft 26 of figures 3 and 4 can be made a single unit by integrating an interface element between the two sections 30, 32 to join them together.

[0124] With reference to [Fig. 21], another embodiment of the steering column 20 can thus be considered, in which the angular locking mechanism 40 extends to the interface between the column body 22 and the steering shaft 26 extending into the bore 23, with: - the nuts 44, 46 which extend radially around the single steering shaft 26 which carries them, here formed of a single section, being rotationally fixed to it while retaining a longitudinal sliding capacity; and - the housing 42 is carried by the column body 22, extending into the bore 23.

[0125] As regards the locking mechanism 40 as such, the housing 42 has been described as comprising two internal threads 52, 54 arranged at iso-distance from the median zone 42c, of opposite orientations and of the same nature, namely: of the same length, of the same pitch and with the same number of threads. However, it may be a different arrangement, for example by forming a thread 52, 54 of greater length but with more threads so that the nut 44, 46 with which it cooperates moves over a greater length for a given angle of rotation, which makes up for the difference in length to achieve the same result.

[0126] Also, the locking mechanism 40 is not limited to any particular thread profile of the internal threads 52, 54 of the housing 42 and consequently of the external threads of the nuts 44, 46. In the illustrated examples the threads have a triangular profile, also called metric thread, but a round, sawtooth, square, trapezoidal or any other profile can be retained without going out of the scope of the invention.

[0127] It should also be noted that the cooperation between the nuts 44, 46 and the housing 42 can be ensured by ball threads, limiting friction at their interface and thus reducing wear.

[0128] The invention is also not limited to the materials of the housing 42 and the nuts 44, 46, which are chosen according to their mechanical resistance to the stresses to be met. By way of example, the nuts 44, 46 can be made of steel or plastic.

[0129] The mounting of the double-threaded housing 42 on the arm 24 or the column body 22, depending on the embodiment considered, has been recommended to be floating, namely allowing longitudinal movement of the housing 42 to secure the compensation of the longitudinal forces F44, F46.

[0130] It should be noted that the invention is not limited to this feature. In practice, the housing 42 can be rigidly fixed to the arm 24, or the column body 22, satisfactorily provided that the proper positioning of the nuts 44, 46 is controlled. assembly to achieve their simultaneous support against the bosses 50a, 50b, and therefore a simultaneous increase in force F44, F46.

[0131] On this basis, it may in such a case be envisaged to form the bosses 50a, 50b directly on the arm 24 or the column body 22. As understood, the invention is not strictly limited to the fact that the housing 42 ensures the role of a means of limiting the longitudinal stroke of the nuts 44, 46. In other words, the locking mechanism 40 is not specifically limited to a particular means of limiting the longitudinal stroke of the nuts 44, 46 when they move away from each other.

[0132] Also, following this logic, it may in particular be decided to form the internal threads 52, 54 directly at the level of the arm 24, or of the column body 22, depending on the embodiment considered, namely: - directly onto the inner surface of the arm 24, oriented towards the steering shaft 26, in the case of the embodiment variant shown in Figures 3 to 18; or - directly on the inner surface of the delimitation of the bore 23 by the column body 22, oriented towards the steering shaft 26, in the case of the variant embodiments of figures 19a-19b and 20a-20b.

[0133] Indeed, if the housing 42 can be fixed relative to the arm 24, or to the column body 22, then it can be directly replaced by the arm 24 or the column body 22 itself. As understood, the housing 42 is not necessarily an integral part of the locking mechanism 40 according to the invention.

[0134] Finally, it should be noted that the sliding joint, which ensures the rotational coupling of the nuts 44, 46 with the steering shaft 26 and a translational guidance of the nuts 44, 46 along the longitudinal axis AX, is not strictly limited to the cooperation between the nuts 44, 46 and the steering shaft 26. Indeed, it is entirely possible to add a part, such as a hollow rod, to the steering shaft 26 to cooperate with the nuts 44, 46. In such a case, the part forms a radial extension of the steering shaft 26.

[0135] In view of the different variants of embodiments described, a steering column 20 according to the invention can be defined generically as comprising: - a steering shaft intended to carry a steering wheel of the vehicle, this steering shaft 26 being carried by the column body 22 along a longitudinal axis AX and having the capacity to rotate around this longitudinal axis; - a structural element blocked against rotation about the longitudinal axis, in which the steering shaft 26 extends at least partially, this structural element being able to designate either the arm 24 within the framework of the steering column arrangement described on the basis of Figures 3 to 18, or the column body 22 within the framework of the variant embodiments of Figures 19a-19b, 20a-20b and 21; and - an angular locking mechanism 40 ensuring cooperation between the structural element and the steering shaft 26 to limit a rotation of the steering shaft 26 around the longitudinal axis AX.

[0136] On this basis, the angular locking mechanism 40 is generically defined as comprising: - a first and a second internal threads 52, 54 of opposite orientations and offset from each other longitudinally, this first and second threads 52, 54 being blocked in rotation around the longitudinal axis AX by being carried indirectly (via the housing 42) or directly by the structural element (direct formation of the internal threads on the inner surface of the arm 24 or the column body 22); - a first and a second nut 44, 46 extending radially to the longitudinal axis AX between the structural element and the steering shaft 26, these first and second nuts 44, 46 each comprising an external thread 60, 62 cooperating with one of the corresponding internal threads 52, 54; - sliding means between the nuts 44, 46 and the steering shaft 26 to ensure both a rotational coupling of the nuts 44, 46 with the steering shaft 26 and a translational guidance of these nuts 44, 46 along the longitudinal axis AX, these sliding means jointly ensuring with the internal threads 52, 54 a longitudinal displacement of the nuts 44, 46 in response to a rotation of the steering shaft 26 so that the nuts 44, 46 move away from each other in a first direction RI of rotation of the steering shaft 26 and move towards each other in a second direction R2) of rotation of the steering shaft 26; — means for limiting the longitudinal travel of the nuts (44, 46) when they move apart (like the bosses 50a, 50b) and move closer together (like the collar 56) longitudinally from each other for a predefined angle of rotation of the steering shaft 26 in the first direction of rotation RI and the second direction of rotation R2.

[0137] Note that each nut 44, 46 can, as such, constitute a means for limiting the longitudinal travel of the other nut when they move closer together, as described on the basis of the housing arrangement 42 without a collar 56 as illustrated in [Fig. 17].

Claims

1. Demands Steering column assembly (20) for a vehicle steering system, for example of an automobile, comprising: - a steering shaft (26) intended to carry a steering wheel of the vehicle, this steering shaft (26) extending along a longitudinal axis (AX) and having the capacity to rotate around this longitudinal axis (AX); - a structural element (22, 24) blocked in rotation around the longitudinal axis, in which the steering shaft (26) extends at least partially; - an angular locking mechanism (40) ensuring cooperation between the structural element (22, 24) and the steering shaft (26) to limit a rotation of the steering shaft (26) around the longitudinal axis (AX) according to a predefined angle of rotation of the steering shaft (26) in a first direction of rotation (RI) and in a second direction of rotation (R2), this angular locking mechanism (40) comprising: — a first and a second internal threads (52, 54) centered on the longitudinal axis (AX), of opposite orientations and offset from each other longitudinally, this first and second threads (52, 54) being blocked in rotation around the longitudinal axis (AX) by being carried directly or indirectly by the structural element (22, 24); — a first and a second nut (44, 46) centered on the longitudinal axis (AX) extending radially to the longitudinal axis (AX) between the structural element (22, 24) and the steering shaft (26), these first and second nuts (44, 46) each comprising an external thread (60, 62) cooperating with one of the corresponding internal threads (52, 54); — sliding means between the nuts (44, 46) and the steering shaft (26) to ensure both rotational coupling of the nuts (44, 46) with the steering shaft (26) and translational guidance of the nuts (44, 46) along the longitudinal axis (AX), these sliding means, together with the cooperation of the threads (52, 60; 54, 62), ensuring longitudinal displacement of the nuts (44, 46) in response to a rotation of the steering shaft (26) so that the nuts (44, 46) move away from each other in the first direction (RI) of rotation of the steering shaft (26) and approach each other in the second direction (R2) of rotation of the steering shaft (26); — means (56, 50a, 50b) for limiting the longitudinal travel of the nuts (44, 46) when they move away from and approach each other longitudinally for a predefined angle of rotation of the steering shaft (26) in the first direction of rotation (RI) and the second direction of rotation (R2).

2. Steering column assembly (20) according to claim 1, comprising a column body (22) which carries the steering shaft (26), this column body (22) being intended to be mounted on a vehicle structure; in which: - the steering shaft (26) is fixed relative to the column body along the longitudinal direction (AX); - the column body (22) forms the structural element which cooperates with the steering shaft (26) by means of the angular locking mechanism (40) to limit a rotation of the steering shaft (26) around the longitudinal axis (AX).

3. Steering column assembly (20) according to claim 1, comprising a column body (22) which carries the steering shaft (26), this column body (22) being intended to be mounted on a vehicle structure;in which: - the steering shaft (26) includes two coaxial sections (30, 32) at least partially nested one inside the other, of which a first section (30) is free in rotation about the longitudinal axis (AX) and fixed in longitudinal translation relative to the column body (22) which carries it, and a second section (32) which is provided to carry the steering wheel of the vehicle, this second section (32) surrounding the first section (30) being both coupled in rotation with this first section (30) and movable in longitudinal translation relative to this first section (30) in a first direction (S1) of deployment and a second direction (S2) of retraction between a fully deployed shaft position, in which the steering shaft (26) has the greatest measured longitudinal extent, and a fully retracted shaft position in which the arm has the smallest measured longitudinal extent; - the column body (22) forms the structural element which cooperates with the first section (30) of the steering shaft (26) by means of the angular locking mechanism (40) to limit a rotation of the steering shaft (26) around the longitudinal axis (AX).

4. Steering column assembly (20) according to claim 3, comprising an arm (24), centered on the longitudinal axis (AX), which is carried by the column body (22) by being at least partially fitted into a bore (23) delimited by this column body (22), the arm (24) radially surrounding the steering shaft (26) being both blocked in rotation about the longitudinal axis (AX) and movable in translation about this longitudinal axis (AX) relative to the column body (22); in which the second section (32) radially surrounds the first section (30); the steering column assembly (20) being shaped so that, in the fully retracted position of the shaft, the arm (24) extends a distance (H) from the bore at which the angular locking mechanism (40) is installed.

5. Steering column assembly (20) according to claim 3, wherein: - the column body (22) delimits a bore (23) in which the first section (30) of the steering shaft (26) extends at least partially; - the arm (24) extends radially outside the bore (23); - the first section (30) radially surrounds the second section (32); and - the angular locking mechanism (40) is arranged in the bore (23).

6. Steering column assembly (20) according to claim 1, comprising: - a column body (22) which carries the steering shaft (26), this column body (22) being intended to be mounted on a vehicle structure; - an arm (24), centered on the longitudinal axis (AX), which is carried by the column body (22) by being at least partially fitted into a bore (23) defined by this column body (22), the arm (24) radially surrounding the steering shaft (26) being both rotationally fixed about the longitudinal axis (AX) and movable in translation along this longitudinal axis (AX) relative to the column body (22);in which: - the steering shaft (26) includes two coaxial sections (30, 32) at least partially nested one inside the other, of which a first section (30) is free in rotation about the longitudinal axis (AX) and fixed in longitudinal translation relative to the column body (22) which carries it, and a second section (32) which is intended to carry the steering wheel of the vehicle, this second section (32) surrounding the first section (30) being both coupled in rotation with this first section (30) and movable in longitudinal translation relative to this first section (30) in a first direction (SI) of deployment and a second direction (S2) of retraction between a deployed shaft position, in which the steering shaft (26) has the greatest measured longitudinal extent, and a retracted shaft position in which the arm has the smallest measured longitudinal extent;- the second section (32) of the steering shaft (26) being fixed in longitudinal translation with the arm (24); - the arm (24) forms the structural element which cooperates with the second section (32) of the steering shaft (26) by means of the angular locking mechanism (40) to limit a rotation of the steering shaft (26) around the longitudinal axis (AX), the first and second internal threads (52, 54) being carried directly or indirectly by the arm (24).

7. Steering column assembly (20) according to any one of claims 1 to 6, wherein: - the angular locking mechanism (40) comprises a housing (42) centered on the longitudinal axis (AX) radially surrounding the first and second nuts (44, 46), this housing extending within the structural element (22, 24) and being blocked in rotation by the structural element (22, 24), and - the first internal thread (52) and the second internal thread (54) are formed on the inner surface of the housing (42).

8. Steering column assembly (20) according to claim 7, wherein the housing (42) is blocked in rotation by the structural element (22, 24) while retaining a degree of freedom in longitudinal sliding along this structural element (22, 24).

9. Steering column assembly (20) according to any one of claims 1 to 6, wherein the first internal thread (52) and the second internal thread (54) are formed directly on the structural element (22, 24).

10. Steering column assembly (20) according to any one of the preceding claims, wherein the means forming a slide between each nut (44, 46) and the steering shaft (26) correspond to the association of at least one longitudinal groove (68) with at least one longitudinal rib (64, 66) which engage with each other; wherein, for each nut (44, 46), one of the rib (64, 66) and the groove (68) is formed by the nut while the other of the rib (64, 66) and the groove (68) is carried directly or indirectly by the steering shaft (26).

11. Steering column assembly (20) according to any one of the preceding claims, wherein the means (56, 50a, 50b) for limiting the longitudinal travel of the nuts (44, 46) comprise two bosses (50a, 50b) which each extend longitudinally opposite a corresponding nut (44, 46) in the away direction to form directly or indirectly a longitudinal stop surface against which this nut bears.

12. Steering column assembly (20) according to claim 11 combined with claim 7 or 8, wherein the bosses (50a, 50b) are formed by the housing (42).

13. Steering column assembly (20) according to claim 11 or 12, wherein the angular locking mechanism (40) comprises rolling element stops (74) carried by bosses (50a, 50b) against which the nuts (44, 46) bear in the away direction.

14. Steering column assembly (20) according to any one of the preceding claims, wherein the means (56, 50a, 50b) for limiting the longitudinal stroke of the nuts (44, 46) comprise a collar (56) which separates the first internal thread (52) and the second internal thread (54) to form a stop for limiting the longitudinal stroke of the nuts (44, 46) in their direction of approach.

15. Steering column assembly (20) according to claim 14 combined with claim 7 or 8, wherein the collar (56) is formed by the housing (42). 33

16. Steering column assembly (20) according to any one of claims 1 to 13, wherein each nut (44; 46) constitutes a means of limiting longitudinal travel for the other nut (46; 44) by forming a bearing surface against which the other nut butts in the approach direction.

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