Title of Invention	STABILISER FOR A MOTOR VEHICLE
Abstract	A stabiliser for a motor vehicle with two shafts extending in the vehicle transverse direction which can be coupled with one another by means of a mechanical coupling (40), which are respectively actively connected to tyres of the motor vehicle by their ends remote from the coupling (40). A first shaft is connected to a first coupling half provided in the form of a catch plate and a second shaft is connected to a second coupling half provided in the form of catch means (8) co-operating with the catch plate. The catch means (8) comprises an actuatable catch element (12A, 12B) which can be driven by means of a drive source (15) against a spring mechanism of a cam plate (11) which can be driven in rotation and a locking member (13A, 13B) joined to it, by means of which the shafts are connected to one another so that they rotate in unison due to a non-positive connection between the catch plate and the locking member (12A, 12B) when the cam plate (11) is in a first end position, and the non-positive connection is released when the cam plate (11) is in a second end position. For the purpose of the invention, the catch element (12A, 12B) is provided with two lever arms (12A_1,12A_2,12B_1,12B_2) rigidly joined to one another, each of which is provided with a contact region (12A_1A, 12A_2A, 12B_1A, 12B_2A) by means of which the lever arms (12A_1,12A_2,12B_1,12B_2) make contact with the cam plate (11).

Title of Invention

STABILISER FOR A MOTOR VEHICLE

Abstract

A stabiliser for a motor vehicle with two shafts extending in the vehicle transverse direction which can be coupled with one another by means of a mechanical coupling (40), which are respectively actively connected to tyres of the motor vehicle by their ends remote from the coupling (40). A first shaft is connected to a first coupling half provided in the form of a catch plate and a second shaft is connected to a second coupling half provided in the form of catch means (8) co-operating with the catch plate. The catch means (8) comprises an actuatable catch element (12A, 12B) which can be driven by means of a drive source (15) against a spring mechanism of a cam plate (11) which can be driven in rotation and a locking member (13A, 13B) joined to it, by means of which the shafts are connected to one another so that they rotate in unison due to a non-positive connection between the catch plate and the locking member (12A, 12B) when the cam plate (11) is in a first end position, and the non-positive connection is released when the cam plate (11) is in a second end position. For the purpose of the invention, the catch element (12A, 12B) is provided with two lever arms (12A_1,12A_2,12B_1,12B_2) rigidly joined to one another, each of which is provided with a contact region (12A_1A, 12A_2A, 12B_1A, 12B_2A) by means of which the lever arms (12A_1,12A_2,12B_1,12B_2) make contact with the cam plate (11).

Full Text	FORM 2 THE PATENT ACT 1970 (39 of 1970) & The Patents Rules, 2003 COMPLETE SPECIFICATION (See Section 10, and rule 13) 1. TITLE OF INVENTION STABILISER FOR A MOTOR VEHICLE 2. APPLICANT(S) a) Name : ZF FRIEDRICHSHAFEN AG b) Nationality : GERMAN Company c) Address : 88038 FRIEDRICHSHAFEN GERMANY 3. PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed : - The invention relates to a stabiliser for a motor vehicle of the type defined in more detail in the introductory part of claim 1. Patent specification DE 101 26 928 Al discloses a stabiliser of the type mentioned above, with a torsion spring bar split into two shafts, which can be connected to one another by means of a mechanical coupling. The coupling has a catch plate connected so as to rotate in unison with a first shaft, the circumference of which is provided with at least one catch region. A housing is also provided, connected so as to rotate in unison with the second shaft. Displaceably mounted on the housing is at least one catch means complementing the catch region of the catch plate, which engages with the catch region so as to close the coupling when the coupling is in the coupled state, and the two shafts are connected to one another so that they rotate in unison. A spring is also connected to the housing and to the catch means, by means of which the catch means is biased in the direction of the catch plate. In order to switch between the coupled and the uncoupled state of the coupling, a releasing mechanism with a drive source is connected to the housing, by means of which the catch means is held out of engagement with the catch region opposing the force expended by the spring in the uncoupled state. However, the disadvantage of the stabiliser known from the prior art is that the catch means, which is moved against the spring force of the spring and out of engagement with the catch plate against an additional retaining force resulting from the friction between the catch means and the catch plate during the operation of uncoupling the coupling, is accelerated once it has overcome the frictional force or the additional retaining force, so that the catch means is abruptly disengaged from the catch plate and hits the housing of the stabiliser at high speed, resulting in undesirable and uncomfortable impacts which are perceived by the driver. Accordingly, the underlying objective of the present invention is to propose a 2 stabiliser for a motor vehicle which is not subjected to any impacts which impair driving comfort during actuation. This objective is achieved by the invention on the basis of a stabiliser having the characterising features defined in claim 1. The stabiliser for a motor vehicle proposed by the invention, which has two shafts extending in the vehicle transverse direction which can be coupled with one another by means of a mechanical coupling, which shafts actively connect with tyres of the vehicle by means of their ends remote from the coupling respectively, and a first shaft is connected to a first coupling half in the form of a catch plate and a second shaft is connected to a second coupling half in the form of a catch means cooperating with the catch plate, and the catch means has a catch element which can be activated so as to be driven in rotation against a spring mechanism and a locking member connected to it, by means of which the shafts are connected so as to rotate in unison when the cam plate is in a first end position due to a non-positive connection between the cam plate and the locking member, and the non-positive connection is released when the cam plate is in a second end position, and the stabiliser can advantageously be uncoupled or disengaged in such a way that the uncomfortable impacts known to occur with the prior art are avoided. This is achieved due to the fact that the catch element is provided with two lever arms rigidly joined to one another that have a common pivot point and the lever arms are each provided with a contact region by means of which the lever arms make contact with the cam plate. This means that the locking member connected to the catch element can be moved into engagement with the catch plate or out of engagement with the catch plate, depending on a rotation of the cam plate, and the movement of the catch element is exactly defined in the area of the contact regions of the lever arms due to the twofold contact between the cam plate and the catch element so that the catch element is 3 prevented from being lifted off the cam plate into the contact regions of the lever arms in a simple manner, even when the retaining force resulting from the frictional force between the locking member and the catch plate has been overcome. Other advantages and advantageous embodiments of the subject matter of the invention will become apparent from the claims and the operating mode of an example of an embodiment described with reference to the appended drawings. Of these: Fig. 1 is a three-dimensional diagram of a stabiliser for a motor vehicle proposed by the invention; Fig. 2 is a three-dimensional, partial view showing a region indicated by B2 in Fig. 1 on a larger scale and in more detail; Fig. 3 is a three-dimensional, partial view in more detail showing a region indicated by B3 in Fig. 2; Fig. 4 shows a cam plate of the stabiliser illustrated in Fig. 1 co-operating with two catch elements; Fig. 5 is a three-dimensional, view showing only the cam plate illustrated in Fig. 4; Fig. 6 is a three-dimensional view showing only a catch element of the stabiliser; Fig. 7 is a three-dimensional -view showing only a catch plate of the stabiliser illustrated in Fig. 1 co-operating with a locking element joined to a catch element; and Fig. 8 is a diagram on a larger scale providing a more detailed illustration of only a region indicated by B8 in Fig. 7. Fig. 1 is a three-dimnensional view illustrating a stabiliser 1 for a motor vehicle as proposed by the invention, comprising two shafts 2, 3 which extend in the vehicle transverse direction in the fitted position and which can be coupled with one another by means of a mechanical coupling 40 illustrated in more detail in Fig. 2. When the coupling 40, disposed in a housing 4, is in the closed or coupled state, the two shafts 2,3 form a torsion spring bar and in this instance extend into the housing 4 by their ends which can be mutually connected by means of the coupling 40, and the second shaft 3 is connected to the housing 4 so as to rotate in unison with it. The housing 4 is closed by a housing cover 5 by means of screws 6, in which the first shaft 2 is rotatably mounted. The first shaft 2 and the second shaft 3 can also be separated from one another by means of the mechanical coupling 40 so that the first shaft 2 can be turned within a predefined angular range relative to the second shaft 3. This state of the coupling 40 will be referred to below as the uncoupled or opened state of the coupling. At their ends remote from the housing 4, the shafts 2, 3 are actively connected to tyres of a vehicle axle of the vehicle in a manner known per se and when the coupling is closed, an interlocking of the vehicle axle is severely impaired by the stabiliser 1 which is then active. It is preferable for the stabiliser 1 to be in the closed state when the vehicle is operating on normal roads and at higher speeds of the vehicle, for reasons of better driving stability. However, when the vehicle is being operated off-road, the coupling 40 is opened to deactivate the operating mode of the stabiliser 1 in a manner which is known per se, permitting interlocking of the vehicle axle to an essentially greater degree than is possible when the stabiliser 1 is activated, so that good traction can still be obtained when the vehicle is on very uneven ground because the two tyres remain essentially in contact with the ground, even in the event of a greater degree of unevenness. 5 To enable actuation in order to activate Or deactivate the stabiliser 1 as described above, the first shaft 2 is connected to a first coupling half designed as a catch plate 7 in the manner illustrated in Fig. 2 and the second shaft 3 is connected to a second coupling half of the coupling 40 designed as a catch means 8 co-operating with the catch plate 7. The catch means 8 in this instance has two catch elements 12A and 12B which can be actuated by means of a drive source 9 against a rotatably driveable cam plate 11 of a spring mechanism 10 illustrated in more detail in Fig. 3, and locking members 13A and 13B, illustrated in more detail in Fig. 4, respectively connected thereto, and the cam plate 11 is mounted so as to be rotatable on the catch plate 7. When the coupling 40 is closed, a non-positive connection is established between the catch plate 7 and the locking members 13A and 13B respectively and the shafts 2 and 3 are connected to one another so as to rotate in unison in a first end position of the cam plate 11 equivalent to the closed state of the coupling 40. When the coupling 40 is opened, the non-positive connection between the locking members 13A and 13B and the catch plate is released, and the cam plate 11 is in a second end position equivalent to the opened state of the coupling 40. The two catch elements 12A and 12B fixedly connected to the housing 4 are each provided with two lever arms 12A_1,12A_2 and 12B_1,12B_2 rigidly joined to one another, which respectively have a common pivot point 14A, 14B. The lever arms 12A_1, 12A_2 respectively 12B_1, 12B_2 are also respectively provided with a contact region 12A_1A, 12A_2A respectively 12B_1A, 12B_2A, in which the lever arms 12A_1, 12A_2 respectively 12B_1, 12B_2 each simultaneously make contact with the cam plate 11, so that a rotation of the cam plate 11 causes the catch elements 12A and 12B to pivot about the respective corresponding pivot point 14A respectively 14B without interrupting the twofold contact between the catch elements 12A and 12B and the cam plate 11. The screws 6A and 6B provided as a means of securing the housing cover 5 on the 6 housing 4 constitute two pivot points 14A and 14B of the catch elements 12A and 12B in this instance, and the catch elements 12A and 12B are fixedly secured to the housing 4 and hence also to the second shaft 3. As may be seen from the diagram shown in Fig. 2, certain regions of the second shaft 3 are provided in the form of a hollow shaft or tube, in the interior of which is integrated the drive source 9 provided with an electric motor 15, which is actively connected to the cam plate 11 in order to drive the cam plate 11 against a spring force of the spring mechanism 10 incorporating a helical spring 17 illustrated in more detail in Fig. 3, by what in this instance is a two-stage gear mechanism 16. The helical spring 17 is fixedly secured on the housing by means of its end facing the electric motor 15 and is tensed to an increasing degree by a rotating motion emitted by the electric motor 15 which moves the cam plate 11 out of the first end position equivalent to the closed state of the coupling 40 of the stabiliser 1 in the direction of the second end position equivalent to the opened state of the coupling 40. This tension causes the spring mechanism 10 to move the cam plate 11 back from the second end position into its first end position when the electric motor 15 is not supplied with power, and the locking members 13A and 13B of the two catch elements 12A and 12B overlap locking indentations 18A, 18B of the catch plate 7 cooperating with them, illustrated in detail in Fig. 7, so that the locking members 13 A and 13B can be latched into the locking indentations 18A and 18B and moved into engagement with the catch plate 7. At its end remote from the electric motor 15, the helical spring 17 of the spring mechanism 10 is connected to a motor output shaft 27 of the electric motor 15, which motor output shaft 27 is actively connected to the rotor of the electric motor 15, although this is not illustrated, so that the spring force of the spring mechanism 10 acting in the closing direction of the coupling 40 can be applied to the cam plate 11 via the two-stage gear unit 16. On its side facing the gear unit 16, the cam plate 11 is provided with a gear 42, which forms a part of the gear unit 16 and meshes with 7 another gear 28 of the gear unit 16. The purpose of the two-stage gear unit 16 is firstly to increase the torque of the driving torque of the electric motor 15 and secondly to bridge a central offset which might exist between the electric motor 15 and the cam plate 11 in the region between the rotation axis of the motor output shaft 27 and the cam plate 11. Fig. 4 is a three-dimensional diagram illustrating the two catch elements 12A and 12B and the cam plate 11 in a more detailed view indicated by arrow A in Fig. 2. The cam plate 11 and one of the two essentially identical catch elements 12A and 12B are also illustrated respectively on their own in Fig. 5 and Fig. 6. As may be seen from the diagram of the cam plate 11 given in Fig. 4 and Fig. 5, the cam plate 11 is of an essentially elliptical design and is provided with a narrowed region 19A respectively 19B on each side in the region of its short half-axes. Due to its reduced elliptical contour, the cam plate 11 constitutes a control track 41 for the two catch elements 12A and 12B, which, in the manner illustrated in Fig. 4, lie by with their lever arms 12A_1, 12A_2 respectively 12B_1 and 12B_2 at their sides facing the control track 41 against the convex contact regions 12A_1A, 12A_2A respectively 12B_1A and 12B_2A without any clearance so that the catch elements 12A and 12B are each pivoted about their pivot points 14A and 14B in an exactly predefined manner on travelling across the control track 41 of the cam plate 11 incorporating different radii of curvature around the circumference of the cam plate 11. As this happens, as the cam plate 11 effects a rotation from its first end position equivalent to the closed state of the coupling 40 in which the locking members 13A and 13B are engaged with the catch plate 7, the two narrowed regions 19A and 19B cause the locking members 13A and 13B to be moved out of engagement with the catch plate 7, essentially radially outwards by reference to the catch plate 7 initially, i.e. perpendicular to the rotation axis of the cam plate 11, during which the locking 8 members 13 A and 13B describe a cam track with a large radius of curvature. This ensures that flanks 20A, 20B of the locking indentations 18A and 18B can be extracted at steep angles of incidence so that the non-positive connection which exists between the locking members 13A and 13B and the catch plate 7 when the coupling 40 is in the closed state affords a strong locking action between the two shafts 2 and 3 of the stabiliser 1. The cam plate 11 is also provided with three collar-type regions 21, 22 and 23 extending out from certain regions in the circumferential direction, the two collar-type regions 22 and 23 being provided as stops for a bolt 24 fixedly secured to the housing. Disposed between the two collar-type regions 22 and 23 is a control groove 25 extending across a predefined angular segment, in which the bolt 24 fixedly secured to the housing locates so that the cam plate 11 is disposed in one of the end positions described above when the bolt 24 lies against one of the collar type regions or stops 22 or 23 and is no longer able to turn in the direction locked by the respective collar-type region 22 or 23. The collar-type region 21, on the other hand, is a constituent part of an indicator unit in this instance, which co-operates with position detection sensors of the indicator unit disposed on a circuit board 26 illustrated in more detail in Fig. 2, so that a current position of the cam plate 11 can be detected by means of the position detection sensors, which are preferably provided in the form of Hall-effect sensors in this instance. Although not illustrated, the two Hall-effect sensors are positioned adjacent to one another in the direction of rotation of the cam plate 11 so that the movement and the current position of the cam plate 11 can be detected in a simple manner by means of milled regions machined into the collar-type region 21. Fig. 6 illustrates one of the identically designed catch elements 12A respectively 12B by way of example. As may be seen from this larger scale diagram illustrating the catch element 12A respectively 12b on its own, the convex contact regions 12A_1A, 9 12A_2A, 12B_1 A, 12B_2A of the lever arms 12A_1,12A_2,12B_1,12B_2 are of a flat design across the width of the lever arms 12A_1 and 12A_2 so that a linear contact exists between the control track 41 of the cam plate 11 and the catch elements 12A respectively 12B in the contact regions 12A_1A, 12A_2A, 12B_1A, 12B_2A. This ensures firstly that a friction force occurring between the control track 41 and the contact regions 12A_1A, 12A_2A respectively 12B_1A, 12B_2A during a rotating motion of the cam plate 11 and opposing the rotating motion of the cam plate 41 is kept low and secondly that a tilting movement of the catch elements 12A respectively 12B occurring due to the control force of the control track 41 of the cam plate 11 acting on the catch elements 12A and 12B and torques transmitted via the locking members 13A and 13B to the catch elements 12A and 12B respectively as a result of the engagement of the locking elements 13A and 13B in the catch plate 7 are reduced. As illustrated in the diagram shown in Fig. 6, the catch elements 12A respectively 12B are additionally provided with lever part-arms 12A_2B, 12B_2B extending parallel with the lever arms 12A_2 and 12B_2, which in conjunction with the lever arms 12A_2 and 12B_2, respectively form a mount 29 for the locking members 13A and 13B and which are disposed in the region of the mount 29 at a distance from the lever arms 12A_2 and 12B_2. This enables a force acting on the locking member 13A in the radial direction or perpendicular to the mid-axis of the catch plate 7 to be better counteracted because the forces acting on the locking members 13A and 13B are better supported by means of the widened mount 29 and can be transmitted via the catch element 12A respectively 12B to the housing 4 of the stabiliser 1. Naturally, it is within the ability of the person skilled in the art to fill the gap between the lever arm 12A_2 respectively 12B_2 and the lever part-arm 12A_2B respectively 12B_2B with material, to suit the intended application, although the embodiment of the catch element 12A respectively 12B illustrated in Fig. 6 has the advantage of a lower component weight due to the reduced amount of material used. 10 Fig. 7 is a diagram on a larger scale illustrating the catch plate 7 on its own, which is connected to the first shaft 2 by means of a splined region 43 so as to rotate in unison with it, whilst Fig. 8 provides a more detailed illustration on a larger scale of the region B8 indicated in Fig. 7. The locking member 13A in Fig. 8 is illustrated in four different positions by reference to the catch plate 7, the four different positions of the locking member 13A being specifically denoted by reference numerals 13A_1, 13A_2,13A_3 and 13A_4. When the locking member 13A is in the position denoted by 13A_l, the coupling 40 is closed because in this position, the locking member 13 A is disposed entirely in the locking indentation 18A and lies completely against the flanks 20A as well as a bottom boundary surface 30 of the locking indentation 18A without any clearance. This means that an operating mode of the stabiliser 1 when the coupling 40 is closed is characterised solely by the elastic properties of the components of the different component units of the stabiliser 1 and an undefined operating mode of the stabiliser 1 due to an undesirable clearance in the contact region between the locking members 13A and 13B and the catch plate 7 is largely prevented. When the locking member 13A is in the position denoted by reference number 13A_4, the coupling 40 between the two shafts 2 and 3 is completely open and the shafts 2 and 3 are turned towards one another. The fully opened or uncoupled state of the stabiliser 1 in this instance is characterised by the distance which exists between the external face 31 of the catch plate 7 and the locking member 13A by which the locking member 13A is pivoted by the catch element 12A completely out of the range of action of the catch plate 7. When the locking member 13A is in the position specifically denoted by reference number 13A_2, the coupling 40 is in what might be termed a preparatory coupled state or preparatory closed state. In this case, the locking member 13A is no longer held by the catch element 12A in the position denoted by reference number 13A_4 11 spaced apart from the surface 31 of the catch plate 7 but lies without any clearance on the external face 31 of the catch plate 7. This state of the coupling 40 and the locking member 13A exists when the two shafts 2,3 are turned towards one another. When the stabiliser 1 is in this operating mode, no positioning force acts on or moves the locking member 13A into its position 13A_1 equivalent to the open state of the coupling by the electric motor 15. If the interlock of the stabiliser 1 is reduced due to correspondingly flat ground underneath the vehicle so that the locking member 13A is moved into the position illustrated by 13A_3, for example, the cam plate 11 can be turned by the spring mechanism 10 in the direction of its end position equivalent to the closed state of the coupling 40 until the locking member 13A is also moved radially in the direction of the mid-axis of the catch plate 7. Since the two shafts 2 and 3 are turned relative to one another so that the locking indentation 18A does not overlap with the locking member 13A when the locking member 13A is in the position indicated by 13A_2, the coupling 40 cannot be transferred to its closed state until the locking member 13A moves so that it at least partially overlaps with the locking indentation 18A of the catch plate 7 as indicated by 13A_3 due to a rotation of the two shafts 2 and 3. This means that a rotation between the two shafts 2 and 3 which is necessary in order to close the coupling 40 finally and hence lock the stabiliser 1 can be effected solely by the spring force of the spring mechanism 10 using an appropriately dimensioned helical spring 17. If the spring force of the spring mechanism 10 is not strong enough to close the coupling 40 starting from the position of the locking member 13A indicated by reference number 13A_3 on its own, the additional activation force may be applied by the electric motor 15. The stabiliser 1 illustrated in Fig. 1 in this instance is designed as an electromechanical system, in which the electric motor 15 rotates the cam plate 11 against 12 the spring mechanism 10 incorporating the helical or spiral spring 17, preferably by 120°, against the stops of the collar-type regions 22 and 23 respectively. The two catch elements 12A and 12B with their locking members 13A and 13B are moved out of the locking indentations 18A and 18B of the catch plate 7 by the cam plate 11 and the locking members 13A and 13B are disposed in the locking indentations 18A and 18B of the catch plate 7 when the system is not being operated. When the cam plate 11 is moved from its first end position in which the stabiliser 1 is coupled into its second end position in which the locking members 13A and 13B are lifted out of the locking indentations 18A and 18B of the catch plate 7 by the catch elements 12A and 12B, the stabiliser 1 is uncoupled and the stabiliser effect preventing an interlocking of the vehicle axle released. When the coupling 40 is in this state, power continues to be applied to the electric motor 15 in order to hold the stabiliser 1 in its uncoupled state and to enable the spring force of the spring mechanism 10 acting in the closing direction of the coupling 40 to be successfully counteracted. The design of the electro-mechanical system or the stabiliser 1 described above constitutes a type of fail-safe mechanism because the spring mechanism 10 acting as a spring resetting unit turns the cam plate 11 if the power supply fails, starting from its end position equivalent to the opened state of the coupling 40 into its end position equivalent to the closed state of the coupling. The locking members 13A and 13B are then pushed back into the locking indentations 18A and 18B of the catch plate 7 when there is an at least partial overlap with the locking indentations as described above, so that the stabiliser 1 is coupled again and the stabiliser action is restored. When the axles are interlocked and when the stabiliser 1 is twisted so that the at least partial overlap between the locking members 13A and 13B and the locking indentations 18A and 18B described above does not exist, the locking members 13A and 13B can not be pushed into the locking indentations 18A and 18B of the catch plate 7 by the spring mechanism 10 because the two shafts 2 and 3 are then turned 13 relative to one another by reference to a zero position in which the stabiliser 1 is locked so that an angular offset between the locking indentations 18A and 18B and the locking members 13A and 13B is too big to close the coupling. In order to close the coupling 40, the zero position in which there exists essentially no one-sided springing in the vehicle axle fitted with the stabiliser 1 is necessary so that the spring mechanism 17, preferably together with the electric motor 15, can push the locking members 13A and 13B back into the locking indentations 18A and 18B of the catch plate 7 with the aid of the cam plate 11. When the coupling 40 is in the opened state, a retaining mechanism 32 is activated, in this instance provided in the form of an electric friction brake, by means of which the cam plate 11 is retained in its end position equivalent to the opened state of the stabiliser 1. Accordingly, it is therefore advantageously possible to reduce the power of the electric motor 15 needed to hold the cam plate 11 in the end position equivalent to the opened state of the stabiliser 1 so that the electric motor 15 does not overheat. For this purpose, the retaining mechanism 32 is used, which in this instance establishes an active connection between the motor output shaft 27 or the rotor of the electric motor 15 and the second shaft 3 and, instead of the suggested solution of using an electric friction brake, any other appropriate solution may be used as a means of protecting the electric motor 15 from potential excess thermal stress. In this respect, the stabiliser may also be designed without the retaining mechanism if there is no possibility of the electric motor being overloaded across the entire operating range of the stabiliser. If a vehicle-side command to close the stabiliser 1 occurs, for example due to actuation of a switch disposed in the passenger compartment, the electric motor 15 and the retaining mechanism 32, if there is one, are deactivated with the aid of the power control system disposed on the circuit board 26 so that the spring mechanism 10 turns both the electric motor 15 and the cam plate 11 back from the position equivalent to the opened state of the stabiliser 1 to the position equivalent to the closed state of the stabiliser and the locking members 13A and 13B are pushed back 14 into the locking indentations 18A and 18B of the catch plate 7. In the event of interlocking of the vehicle axle fitted with the stabiliser 1, during which the two shafts 2 and 3 are turned towards one another and which is characterised by an angular offset between the locking members 13A and 13B and the locking indentations 18A and 18B of the catch plate 7 such that the locking members 13 A and 13B can not be moved into the position in the locking indentations 18A and 18B indicated by reference number 13A_1 in Fig. 8, the electro-mechanical system or the stabiliser 1 is firstly moved into an only partially active state in the manner described above, i.e. the preparatory closed state. When the stabiliser 1 is in the latter operating mode in which the stabihser 1 can not be activated, a sensor system likewise disposed on the circuit board 26 detects the current position of the motor output shaft 27 of the electric motor 15 and deactivates it, depending on the detected position of the cam plate 11. If the interlocking of the vehicle axle is reduced so that there is an angular offset of only up to a maximum of 1.25° between the two shafts 2 and 3 or between the locking member 13A respectively 13B and the locking indentation 18A respectively 18B, the locking members 13A and 13B are pushed into the locking indentations 18A and 18B of the catch plate 7 by means of the spring mechanism 17 and optionally with the assistance of the electric motor 15 which is then reactivated or powered, so that the coupling 40 is closed and the stabiliser 1 is activated again. If the rotation angle between the two shafts 2 and 3 is bigger, the locking members 13A and 13B of the catch elements 12A and 12B can not be pushed into the locking indentations 18A and 18B of the catch plate 7, in which respect this should be taken as meaning rotation angles between the shafts 2 and 3 or between the locking indentations 18A and 18B and the locking members 13A and 13B in excess of 1.25°. In this case, the locking members 13A and 13B lie on the catch plate 7 as indicated by reference number 13 A_2 indicated in Fig. 8. 15 In this connection, it should be pointed out that the threshold angle of the maximum rotation angle between the two shafts 2 and 3 up to which the locking members can be respectively pushed into the co-operating locking indentations in the manner described above is correlated to a friction value factor depending on an opening angle of the relevant locking indentation in each case and resulting from the material pairing of the locking members and the catch plate, and the threshold angle mentioned above may therefore vary from the angular value of 1.25° mentioned above, depending on the respective application. The electronic power system provided on the circuit board 26 for controlling the stabiliser 1 is provided with electronic amplifier elements in this instance, by means of which the signals of the Hall-effect sensors can be amplified. The electronic power system on the circuit board 26 is also provided with a separate control device, although this is not illustrated, which is connected to a CAN bus of the motor vehicle. The control device is supplied with information about the current speed of the vehicle via the CAN bus. If a predefined critical threshold speed is exceeded, the opened stabiliser 1 is locked by closing the coupling 40 so that the vehicle can be stabilised accordingly by the closed stabiliser 1 for the currently detected speed. Finally, it should be pointed out that it lies within the scope of the person skilled in the art to provide the stabiliser proposed by the invention with only one catch element or with more than two catch elements, in which case whatever number of catch elements is selected will not change the way in which the embodiment of the stabiliser 1 illustrated in the appended drawings as an example and explained in more detail in the foregoing description operates. 16 Reference numbers 1 Stabiliser 2 First shaft 3 Second shaft 4 Housing 5 Housing cover 6A,B Screws 7 Catch plate 8 Catch means 9 Drive source 10 Spring mechanism 11 Cam plate 12A,B Catch element 12A_1,12A_2 Lever arm 12B_1,12B_2 Lever arm 12A_1 A, 12A_2A, 12B_1A, 12B_2A Contact region 12A_2B, 12B_2B Lever part-arm 13A,B Locking member 13A_1,13A_2,13A_3,13A_4 Position of the locking member 14A,B Pivot point 15 Electric motor, drive source 16 Gear unit 17 Spring mechanism 18A,B Locking indentations 19A,B Narrowed regions 20A,B Flanks 21,22,23 Collar-type region 24 Bolt 25 Control groove 26 Circuit board 27 Motor output shaft 28 Other gear 29 Mount 31 External face of the catch plate 32 Retaining mechanism 40 Coupling 41 Control track 42 Gear 43 Splined region 17 WE CLAIM: 1. Stabiliser (1) for a motor vehicle with two shafts (2,3) extending in the vehicle transverse direction which can be coupled with one another by means of a mechanical coupling (40), which are respectively actively connected to tyres of the motor vehicle by their ends remote from the coupling (40), and a first shaft (2) is connected to a first coupling half provided in the form of a catch plate (7) and a second shaft (3) is connected to a second coupling half provided in the form of catch means (8) co-operating with the catch plate (7), and the catch means (8) comprises an actuatable catch element (12A, 12B) which can be driven by means of a drive source (9) against a spring mechanism (10) of a cam plate (11) which can be driven in rotation and a locking member (13A, 13B) joined to it, by means of which the shafts (2,3) are connected to one another so that they rotate in unison due to a non-positive connection between the catch plate (7) and the locking member (13A, 13B) when the cam plate (11) is in a first end position, and the non-positive connection is released when the cam plate (11) is in a second end position, characterised in that the catch element (12A, 12B) is provided with two lever arms (12A_l, 12A_2,12B_1,12B_2) rigidly joined to one another which have a common pivot point (14A, 14B), and the lever arms (12A_1, to 12B_2) are each provided with a contact region (12A_1 A, 12A_2A, 12B_1 A, 12B_2A) by means of which the lever arms (12A, 12B) make contact with the cam plate (11). 2. Stabiliser as claimed in claim 1, characterised in that the contact regions (12A_1 A to 12B_2A) of the lever arms (12A_1 to 12B_2) are of a curved design so that an at least approximately linear contact exists between the lever arms (12A_1 to 12B_2) and the cam plate (11). 3. Stabiliser as claimed in claim 1 or 2, characterised in that the locking member (13A, 13B) is provided in the form of a bolt fixedly connected to one of the lever arms (12A_1,12B_1). 18 Stabiliser as claimed in one of claims 1 to 3, characterised in that the catch plate (7) is connected to the first shaft (2) by means of a splined region (43). Stabiliser as claimed in one of claims 1 to 4, characterised in that the catch plate (7) is provided with a locking indentation (18A, 18B) in which the locking member (13A, 13B) is disposed, preferably without any clearance, when the coupling (40) is in the closed state. Stabiliser as claimed in claim 5, characterised in that the locking indentation (18A, 18B) is designed so that the coupling (40) can be closed by means of the spring mechanism (10) when an angular offset exists between the shafts (2, 3) which is smaller than a threshold angle correlated to an opening angle of the locking indentation (18A, 18B), which is preferably 1.25°. Stabiliser as claimed in one of claims 1 to 6, characterised in that the cam plate (11) is mounted so as to be rotatable on the catch plate (7) and is connected to the drive source (9) and the spring mechanism (10) by means of a gear unit (16). Stabiliser as claimed in one of claims 5 to 7, characterised in that the cam plate (11) is provided with an elliptical control track (41) provided with narrowed regions (19 A, 19B) in the region of the short half-axes and on which the lever arms (12A_1 to 12B_2) are guided by their contact regions (12A_1A to 12B_2A) so that the locking member (13A, 13B) is moved essentially radially outwards by reference to the catch plate (7) during a rotating movement of the cam plate (11) starting from a position equivalent to the closed state of the coupling (40) and is thus guided out of the locking indentation (18A, 18B) of the catch plate (7). Stabiliser as claimed in one of claims 1 to 8, characterised in that the cam plate (11) is provided with collar-type regions (21,22,23) extending in certain 19 portions in the circumferential direction and two collar-type regions (22, 23) are provided as stops for a bolt (24) fixedly secured to the housing, and a control groove (25) is provided across a specific angular segment between the two stops (22, 23), in which the bolt (24) engages so that the cam plate (11) is disposed in one of the end positions when the bolt (24) is lying against one of the stops (22 or 23). 10. Stabiliser as claimed in one of claims 1 to 9, characterised in that the cam plate (11) is provided with an indicator unit which co-operates with position detecting sensors so that a current position of the cam plate (11) can be detected by means of the position detecting sensors. 11. Stabiliser as claimed in claim 10, characterised in that the position detecting sensors are provided in the form of Hall-effect sensors. 12 Stabiliser as claimed in one of claims 1 to 11, characterised in that the drive source (9) and the spring mechanism (10) are disposed in at least certain regions of the second shaft (3) provided in the form of a hollow shaft 13. Stabiliser as claimed in one of claims 1 to 12, characterised in that the spring mechanism (10) is provided with a helical spring (17) in the fitted position, which is tensed so that the cam plate (11) is activated in a direction closing the coupling (40). 14 Stabiliser as claimed in one of claims 1 to 13, characterised in that the drive source (9) is provided with an electric motor (15). 15. Stabiliser as claimed in one of claims 1 to 14, characterised in that the lever arm (12A_1,12B_1) of the catch element (12A, 12B) connected to the locking member (13A, 13B) has a lever part-arm (12A_2B/ 12B_2B) extending parallel therewith. 20 16. Stabiliser as claimed in one of claims 1 to 15, characterised in that the active connection between the cam plate (11) and the spring mechanism (10) is provided with a retaining mechanism (32) so that the cam plate (11) can be held in the current position opposing the spring force of the spring mechanism (10). 17. Stabiliser as claimed in claim 16, characterised in that the retaining mechanism (32) is provided in the form of a brake acting on the rotor of the electric motor (15). 18. Stabiliser as claimed in one of claims 10 to 17, characterised in that the position detecting sensors are disposed on a circuit board (26), on which other electronic components for amplifying the signals of the position detecting sensors are disposed. 19. Stabiliser as claimed in one of claims 10 to 18, characterised in that the circuit board (26) is provided with a control device connected to a CAN bus of the motor vehicle, so that the coupling (40) is closed as a function of a control device activation when a critical driving speed is exceeded. 21 Dated this 12th day of January, 2007 Abstract A stabiliser for a motor vehicle with two shafts extending in the vehicle transverse direction which can be coupled with one another by means of a mechanical coupling (40), which are respectively actively connected to tyres of the motor vehicle by their ends remote from the coupling (40). A first shaft is connected to a first coupling half provided in the form of a catch plate and a second shaft is connected to a second coupling half provided in the form of catch means (8) co-operating with the catch plate. The catch means (8) comprises an actuatable catch element (12A, 12B) which can be driven by means of a drive source (15) against a spring mechanism of a cam plate (11) which can be driven in rotation and a locking member (13A, 13B) joined to it, by means of which the shafts are connected to one another so that they rotate in unison due to a non-positive connection between the catch plate and the locking member (12A, 12B) when the cam plate (11) is in a first end position, and the non-positive connection is released when the cam plate (11) is in a second end position. For the purpose of the invention, the catch element (12A, 12B) is provided with two lever arms (12A_1,12A_2,12B_1,12B_2) rigidly joined to one another, each of which is provided with a contact region (12A_1A, 12A_2A, 12B_1A, 12B_2A) by means of which the lever arms (12A_1,12A_2,12B_1,12B_2) make contact with the cam plate (11). To The Controller of Patents The Patent Office Mumbai 22

Full Text

FORM 2
THE PATENT ACT 1970 (39 of 1970)
&
The Patents Rules, 2003 COMPLETE SPECIFICATION
(See Section 10, and rule 13)
1. TITLE OF INVENTION
STABILISER FOR A MOTOR VEHICLE
2. APPLICANT(S)
a) Name : ZF FRIEDRICHSHAFEN AG
b) Nationality : GERMAN Company
c) Address : 88038 FRIEDRICHSHAFEN
GERMANY
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed : -

The invention relates to a stabiliser for a motor vehicle of the type defined in more detail in the introductory part of claim 1.
Patent specification DE 101 26 928 Al discloses a stabiliser of the type mentioned above, with a torsion spring bar split into two shafts, which can be connected to one another by means of a mechanical coupling. The coupling has a catch plate connected so as to rotate in unison with a first shaft, the circumference of which is provided with at least one catch region. A housing is also provided, connected so as to rotate in unison with the second shaft. Displaceably mounted on the housing is at least one catch means complementing the catch region of the catch plate, which engages with the catch region so as to close the coupling when the coupling is in the coupled state, and the two shafts are connected to one another so that they rotate in unison.
A spring is also connected to the housing and to the catch means, by means of which the catch means is biased in the direction of the catch plate. In order to switch between the coupled and the uncoupled state of the coupling, a releasing mechanism with a drive source is connected to the housing, by means of which the catch means is held out of engagement with the catch region opposing the force expended by the spring in the uncoupled state.
However, the disadvantage of the stabiliser known from the prior art is that the catch means, which is moved against the spring force of the spring and out of engagement with the catch plate against an additional retaining force resulting from the friction between the catch means and the catch plate during the operation of uncoupling the coupling, is accelerated once it has overcome the frictional force or the additional retaining force, so that the catch means is abruptly disengaged from the catch plate and hits the housing of the stabiliser at high speed, resulting in undesirable and uncomfortable impacts which are perceived by the driver.
Accordingly, the underlying objective of the present invention is to propose a
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stabiliser for a motor vehicle which is not subjected to any impacts which impair driving comfort during actuation.
This objective is achieved by the invention on the basis of a stabiliser having the characterising features defined in claim 1.
The stabiliser for a motor vehicle proposed by the invention, which has two shafts extending in the vehicle transverse direction which can be coupled with one another by means of a mechanical coupling, which shafts actively connect with tyres of the vehicle by means of their ends remote from the coupling respectively, and a first shaft is connected to a first coupling half in the form of a catch plate and a second shaft is connected to a second coupling half in the form of a catch means cooperating with the catch plate, and the catch means has a catch element which can be activated so as to be driven in rotation against a spring mechanism and a locking member connected to it, by means of which the shafts are connected so as to rotate in unison when the cam plate is in a first end position due to a non-positive connection between the cam plate and the locking member, and the non-positive connection is released when the cam plate is in a second end position, and the stabiliser can advantageously be uncoupled or disengaged in such a way that the uncomfortable impacts known to occur with the prior art are avoided.
This is achieved due to the fact that the catch element is provided with two lever arms rigidly joined to one another that have a common pivot point and the lever arms are each provided with a contact region by means of which the lever arms make contact with the cam plate.
This means that the locking member connected to the catch element can be moved into engagement with the catch plate or out of engagement with the catch plate, depending on a rotation of the cam plate, and the movement of the catch element is exactly defined in the area of the contact regions of the lever arms due to the twofold contact between the cam plate and the catch element so that the catch element is
3

prevented from being lifted off the cam plate into the contact regions of the lever arms in a simple manner, even when the retaining force resulting from the frictional force between the locking member and the catch plate has been overcome.
Other advantages and advantageous embodiments of the subject matter of the invention will become apparent from the claims and the operating mode of an example of an embodiment described with reference to the appended drawings. Of these:
Fig. 1 is a three-dimensional diagram of a stabiliser for a motor vehicle
proposed by the invention;
Fig. 2 is a three-dimensional, partial view showing a region indicated by B2
in Fig. 1 on a larger scale and in more detail;
Fig. 3 is a three-dimensional, partial view in more detail showing a region
indicated by B3 in Fig. 2;
Fig. 4 shows a cam plate of the stabiliser illustrated in Fig. 1 co-operating
with two catch elements;
Fig. 5 is a three-dimensional, view showing only the cam plate illustrated in
Fig. 4;
Fig. 6 is a three-dimensional view showing only a catch element of the
stabiliser;
Fig. 7 is a three-dimensional -view showing only a catch plate of the stabiliser
illustrated in Fig. 1 co-operating with a locking element joined to a catch element; and
Fig. 8 is a diagram on a larger scale providing a more detailed illustration of

only a region indicated by B8 in Fig. 7.
Fig. 1 is a three-dimnensional view illustrating a stabiliser 1 for a motor vehicle as proposed by the invention, comprising two shafts 2, 3 which extend in the vehicle transverse direction in the fitted position and which can be coupled with one another by means of a mechanical coupling 40 illustrated in more detail in Fig. 2. When the coupling 40, disposed in a housing 4, is in the closed or coupled state, the two shafts 2,3 form a torsion spring bar and in this instance extend into the housing 4 by their ends which can be mutually connected by means of the coupling 40, and the second shaft 3 is connected to the housing 4 so as to rotate in unison with it. The housing 4 is closed by a housing cover 5 by means of screws 6, in which the first shaft 2 is rotatably mounted.
The first shaft 2 and the second shaft 3 can also be separated from one another by means of the mechanical coupling 40 so that the first shaft 2 can be turned within a predefined angular range relative to the second shaft 3. This state of the coupling 40 will be referred to below as the uncoupled or opened state of the coupling.
At their ends remote from the housing 4, the shafts 2, 3 are actively connected to tyres of a vehicle axle of the vehicle in a manner known per se and when the coupling is closed, an interlocking of the vehicle axle is severely impaired by the stabiliser 1 which is then active. It is preferable for the stabiliser 1 to be in the closed state when the vehicle is operating on normal roads and at higher speeds of the vehicle, for reasons of better driving stability.
However, when the vehicle is being operated off-road, the coupling 40 is opened to deactivate the operating mode of the stabiliser 1 in a manner which is known per se, permitting interlocking of the vehicle axle to an essentially greater degree than is possible when the stabiliser 1 is activated, so that good traction can still be obtained when the vehicle is on very uneven ground because the two tyres remain essentially in contact with the ground, even in the event of a greater degree of unevenness.
5

To enable actuation in order to activate Or deactivate the stabiliser 1 as described above, the first shaft 2 is connected to a first coupling half designed as a catch plate 7 in the manner illustrated in Fig. 2 and the second shaft 3 is connected to a second coupling half of the coupling 40 designed as a catch means 8 co-operating with the catch plate 7. The catch means 8 in this instance has two catch elements 12A and 12B which can be actuated by means of a drive source 9 against a rotatably driveable cam plate 11 of a spring mechanism 10 illustrated in more detail in Fig. 3, and locking members 13A and 13B, illustrated in more detail in Fig. 4, respectively connected thereto, and the cam plate 11 is mounted so as to be rotatable on the catch plate 7.
When the coupling 40 is closed, a non-positive connection is established between the catch plate 7 and the locking members 13A and 13B respectively and the shafts 2 and 3 are connected to one another so as to rotate in unison in a first end position of the cam plate 11 equivalent to the closed state of the coupling 40. When the coupling 40 is opened, the non-positive connection between the locking members 13A and 13B and the catch plate is released, and the cam plate 11 is in a second end position equivalent to the opened state of the coupling 40.
The two catch elements 12A and 12B fixedly connected to the housing 4 are each provided with two lever arms 12A_1,12A_2 and 12B_1,12B_2 rigidly joined to one another, which respectively have a common pivot point 14A, 14B. The lever arms
12A_1, 12A_2 respectively 12B_1, 12B_2 are also respectively provided with a contact region 12A_1A, 12A_2A respectively 12B_1A, 12B_2A, in which the lever
arms 12A_1, 12A_2 respectively 12B_1, 12B_2 each simultaneously make contact with the cam plate 11, so that a rotation of the cam plate 11 causes the catch elements 12A and 12B to pivot about the respective corresponding pivot point 14A respectively 14B without interrupting the twofold contact between the catch elements 12A and 12B and the cam plate 11.
The screws 6A and 6B provided as a means of securing the housing cover 5 on the
6

housing 4 constitute two pivot points 14A and 14B of the catch elements 12A and 12B in this instance, and the catch elements 12A and 12B are fixedly secured to the housing 4 and hence also to the second shaft 3.
As may be seen from the diagram shown in Fig. 2, certain regions of the second shaft 3 are provided in the form of a hollow shaft or tube, in the interior of which is integrated the drive source 9 provided with an electric motor 15, which is actively connected to the cam plate 11 in order to drive the cam plate 11 against a spring force of the spring mechanism 10 incorporating a helical spring 17 illustrated in more detail in Fig. 3, by what in this instance is a two-stage gear mechanism 16.
The helical spring 17 is fixedly secured on the housing by means of its end facing the electric motor 15 and is tensed to an increasing degree by a rotating motion emitted by the electric motor 15 which moves the cam plate 11 out of the first end position equivalent to the closed state of the coupling 40 of the stabiliser 1 in the direction of the second end position equivalent to the opened state of the coupling 40. This tension causes the spring mechanism 10 to move the cam plate 11 back from the second end position into its first end position when the electric motor 15 is not supplied with power, and the locking members 13A and 13B of the two catch elements 12A and 12B overlap locking indentations 18A, 18B of the catch plate 7 cooperating with them, illustrated in detail in Fig. 7, so that the locking members 13 A and 13B can be latched into the locking indentations 18A and 18B and moved into engagement with the catch plate 7.
At its end remote from the electric motor 15, the helical spring 17 of the spring mechanism 10 is connected to a motor output shaft 27 of the electric motor 15, which motor output shaft 27 is actively connected to the rotor of the electric motor 15, although this is not illustrated, so that the spring force of the spring mechanism 10 acting in the closing direction of the coupling 40 can be applied to the cam plate 11 via the two-stage gear unit 16. On its side facing the gear unit 16, the cam plate 11 is provided with a gear 42, which forms a part of the gear unit 16 and meshes with
7

another gear 28 of the gear unit 16.
The purpose of the two-stage gear unit 16 is firstly to increase the torque of the driving torque of the electric motor 15 and secondly to bridge a central offset which might exist between the electric motor 15 and the cam plate 11 in the region between the rotation axis of the motor output shaft 27 and the cam plate 11.
Fig. 4 is a three-dimensional diagram illustrating the two catch elements 12A and 12B and the cam plate 11 in a more detailed view indicated by arrow A in Fig. 2. The cam plate 11 and one of the two essentially identical catch elements 12A and 12B are also illustrated respectively on their own in Fig. 5 and Fig. 6.
As may be seen from the diagram of the cam plate 11 given in Fig. 4 and Fig. 5, the cam plate 11 is of an essentially elliptical design and is provided with a narrowed region 19A respectively 19B on each side in the region of its short half-axes. Due to its reduced elliptical contour, the cam plate 11 constitutes a control track 41 for the two catch elements 12A and 12B, which, in the manner illustrated in Fig. 4, lie by with their lever arms 12A_1, 12A_2 respectively 12B_1 and 12B_2 at their sides facing the control track 41 against the convex contact regions 12A_1A, 12A_2A respectively 12B_1A and 12B_2A without any clearance so that the catch elements 12A and 12B are each pivoted about their pivot points 14A and 14B in an exactly predefined manner on travelling across the control track 41 of the cam plate 11 incorporating different radii of curvature around the circumference of the cam plate 11.
As this happens, as the cam plate 11 effects a rotation from its first end position equivalent to the closed state of the coupling 40 in which the locking members 13A and 13B are engaged with the catch plate 7, the two narrowed regions 19A and 19B cause the locking members 13A and 13B to be moved out of engagement with the catch plate 7, essentially radially outwards by reference to the catch plate 7 initially, i.e. perpendicular to the rotation axis of the cam plate 11, during which the locking
8

members 13 A and 13B describe a cam track with a large radius of curvature.
This ensures that flanks 20A, 20B of the locking indentations 18A and 18B can be extracted at steep angles of incidence so that the non-positive connection which exists between the locking members 13A and 13B and the catch plate 7 when the coupling 40 is in the closed state affords a strong locking action between the two shafts 2 and 3 of the stabiliser 1.
The cam plate 11 is also provided with three collar-type regions 21, 22 and 23 extending out from certain regions in the circumferential direction, the two collar-type regions 22 and 23 being provided as stops for a bolt 24 fixedly secured to the housing. Disposed between the two collar-type regions 22 and 23 is a control groove 25 extending across a predefined angular segment, in which the bolt 24 fixedly secured to the housing locates so that the cam plate 11 is disposed in one of the end positions described above when the bolt 24 lies against one of the collar type regions or stops 22 or 23 and is no longer able to turn in the direction locked by the respective collar-type region 22 or 23.
The collar-type region 21, on the other hand, is a constituent part of an indicator unit in this instance, which co-operates with position detection sensors of the indicator unit disposed on a circuit board 26 illustrated in more detail in Fig. 2, so that a current position of the cam plate 11 can be detected by means of the position detection sensors, which are preferably provided in the form of Hall-effect sensors in this instance. Although not illustrated, the two Hall-effect sensors are positioned adjacent to one another in the direction of rotation of the cam plate 11 so that the movement and the current position of the cam plate 11 can be detected in a simple manner by means of milled regions machined into the collar-type region 21.
Fig. 6 illustrates one of the identically designed catch elements 12A respectively 12B by way of example. As may be seen from this larger scale diagram illustrating the
catch element 12A respectively 12b on its own, the convex contact regions 12A_1A,
9

12A_2A, 12B_1 A, 12B_2A of the lever arms 12A_1,12A_2,12B_1,12B_2 are of a flat design across the width of the lever arms 12A_1 and 12A_2 so that a linear contact exists between the control track 41 of the cam plate 11 and the catch elements 12A respectively 12B in the contact regions 12A_1A, 12A_2A, 12B_1A, 12B_2A. This ensures firstly that a friction force occurring between the control track 41 and the contact regions 12A_1A, 12A_2A respectively 12B_1A, 12B_2A during a rotating motion of the cam plate 11 and opposing the rotating motion of the cam plate 41 is kept low and secondly that a tilting movement of the catch elements 12A respectively 12B occurring due to the control force of the control track 41 of the cam plate 11 acting on the catch elements 12A and 12B and torques transmitted via the locking members 13A and 13B to the catch elements 12A and 12B respectively as a result of the engagement of the locking elements 13A and 13B in the catch plate 7 are reduced.
As illustrated in the diagram shown in Fig. 6, the catch elements 12A respectively 12B are additionally provided with lever part-arms 12A_2B, 12B_2B extending parallel with the lever arms 12A_2 and 12B_2, which in conjunction with the lever arms 12A_2 and 12B_2, respectively form a mount 29 for the locking members 13A and 13B and which are disposed in the region of the mount 29 at a distance from the lever arms 12A_2 and 12B_2. This enables a force acting on the locking member 13A in the radial direction or perpendicular to the mid-axis of the catch plate 7 to be better counteracted because the forces acting on the locking members 13A and 13B are better supported by means of the widened mount 29 and can be transmitted via the catch element 12A respectively 12B to the housing 4 of the stabiliser 1.
Naturally, it is within the ability of the person skilled in the art to fill the gap between the lever arm 12A_2 respectively 12B_2 and the lever part-arm 12A_2B respectively 12B_2B with material, to suit the intended application, although the embodiment of the catch element 12A respectively 12B illustrated in Fig. 6 has the advantage of a lower component weight due to the reduced amount of material used.
10

Fig. 7 is a diagram on a larger scale illustrating the catch plate 7 on its own, which is connected to the first shaft 2 by means of a splined region 43 so as to rotate in unison with it, whilst Fig. 8 provides a more detailed illustration on a larger scale of the region B8 indicated in Fig. 7. The locking member 13A in Fig. 8 is illustrated in four different positions by reference to the catch plate 7, the four different positions of the locking member 13A being specifically denoted by reference numerals 13A_1, 13A_2,13A_3 and 13A_4.
When the locking member 13A is in the position denoted by 13A_l, the coupling 40 is closed because in this position, the locking member 13 A is disposed entirely in the locking indentation 18A and lies completely against the flanks 20A as well as a bottom boundary surface 30 of the locking indentation 18A without any clearance. This means that an operating mode of the stabiliser 1 when the coupling 40 is closed is characterised solely by the elastic properties of the components of the different component units of the stabiliser 1 and an undefined operating mode of the stabiliser 1 due to an undesirable clearance in the contact region between the locking members 13A and 13B and the catch plate 7 is largely prevented.
When the locking member 13A is in the position denoted by reference number 13A_4, the coupling 40 between the two shafts 2 and 3 is completely open and the shafts 2 and 3 are turned towards one another. The fully opened or uncoupled state of the stabiliser 1 in this instance is characterised by the distance which exists between the external face 31 of the catch plate 7 and the locking member 13A by which the locking member 13A is pivoted by the catch element 12A completely out of the range of action of the catch plate 7.
When the locking member 13A is in the position specifically denoted by reference number 13A_2, the coupling 40 is in what might be termed a preparatory coupled state or preparatory closed state. In this case, the locking member 13A is no longer held by the catch element 12A in the position denoted by reference number 13A_4
11

spaced apart from the surface 31 of the catch plate 7 but lies without any clearance on the external face 31 of the catch plate 7. This state of the coupling 40 and the locking member 13A exists when the two shafts 2,3 are turned towards one another. When the stabiliser 1 is in this operating mode, no positioning force acts on or moves the locking member 13A into its position 13A_1 equivalent to the open state of the coupling by the electric motor 15.
If the interlock of the stabiliser 1 is reduced due to correspondingly flat ground underneath the vehicle so that the locking member 13A is moved into the position illustrated by 13A_3, for example, the cam plate 11 can be turned by the spring mechanism 10 in the direction of its end position equivalent to the closed state of the coupling 40 until the locking member 13A is also moved radially in the direction of the mid-axis of the catch plate 7. Since the two shafts 2 and 3 are turned relative to one another so that the locking indentation 18A does not overlap with the locking member 13A when the locking member 13A is in the position indicated by 13A_2, the coupling 40 cannot be transferred to its closed state until the locking member 13A moves so that it at least partially overlaps with the locking indentation 18A of the catch plate 7 as indicated by 13A_3 due to a rotation of the two shafts 2 and 3.
This means that a rotation between the two shafts 2 and 3 which is necessary in order to close the coupling 40 finally and hence lock the stabiliser 1 can be effected solely by the spring force of the spring mechanism 10 using an appropriately dimensioned helical spring 17.
If the spring force of the spring mechanism 10 is not strong enough to close the coupling 40 starting from the position of the locking member 13A indicated by reference number 13A_3 on its own, the additional activation force may be applied by the electric motor 15.
The stabiliser 1 illustrated in Fig. 1 in this instance is designed as an electromechanical system, in which the electric motor 15 rotates the cam plate 11 against
12

the spring mechanism 10 incorporating the helical or spiral spring 17, preferably by 120°, against the stops of the collar-type regions 22 and 23 respectively. The two catch elements 12A and 12B with their locking members 13A and 13B are moved out of the locking indentations 18A and 18B of the catch plate 7 by the cam plate 11 and the locking members 13A and 13B are disposed in the locking indentations 18A and 18B of the catch plate 7 when the system is not being operated.
When the cam plate 11 is moved from its first end position in which the stabiliser 1 is coupled into its second end position in which the locking members 13A and 13B are lifted out of the locking indentations 18A and 18B of the catch plate 7 by the catch elements 12A and 12B, the stabiliser 1 is uncoupled and the stabiliser effect preventing an interlocking of the vehicle axle released. When the coupling 40 is in this state, power continues to be applied to the electric motor 15 in order to hold the stabiliser 1 in its uncoupled state and to enable the spring force of the spring mechanism 10 acting in the closing direction of the coupling 40 to be successfully counteracted.
The design of the electro-mechanical system or the stabiliser 1 described above constitutes a type of fail-safe mechanism because the spring mechanism 10 acting as a spring resetting unit turns the cam plate 11 if the power supply fails, starting from its end position equivalent to the opened state of the coupling 40 into its end position equivalent to the closed state of the coupling. The locking members 13A and 13B are then pushed back into the locking indentations 18A and 18B of the catch plate 7 when there is an at least partial overlap with the locking indentations as described above, so that the stabiliser 1 is coupled again and the stabiliser action is restored.
When the axles are interlocked and when the stabiliser 1 is twisted so that the at least partial overlap between the locking members 13A and 13B and the locking indentations 18A and 18B described above does not exist, the locking members 13A and 13B can not be pushed into the locking indentations 18A and 18B of the catch plate 7 by the spring mechanism 10 because the two shafts 2 and 3 are then turned
13

relative to one another by reference to a zero position in which the stabiliser 1 is locked so that an angular offset between the locking indentations 18A and 18B and the locking members 13A and 13B is too big to close the coupling.
In order to close the coupling 40, the zero position in which there exists essentially no one-sided springing in the vehicle axle fitted with the stabiliser 1 is necessary so
that the spring mechanism 17, preferably together with the electric motor 15, can
push the locking members 13A and 13B back into the locking indentations 18A and 18B of the catch plate 7 with the aid of the cam plate 11.
When the coupling 40 is in the opened state, a retaining mechanism 32 is activated, in this instance provided in the form of an electric friction brake, by means of which the cam plate 11 is retained in its end position equivalent to the opened state of the stabiliser 1. Accordingly, it is therefore advantageously possible to reduce the power of the electric motor 15 needed to hold the cam plate 11 in the end position equivalent to the opened state of the stabiliser 1 so that the electric motor 15 does not overheat. For this purpose, the retaining mechanism 32 is used, which in this instance establishes an active connection between the motor output shaft 27 or the rotor of the electric motor 15 and the second shaft 3 and, instead of the suggested solution of using an electric friction brake, any other appropriate solution may be used as a means of protecting the electric motor 15 from potential excess thermal stress. In this respect, the stabiliser may also be designed without the retaining mechanism if there is no possibility of the electric motor being overloaded across the entire operating range of the stabiliser.
If a vehicle-side command to close the stabiliser 1 occurs, for example due to actuation of a switch disposed in the passenger compartment, the electric motor 15 and the retaining mechanism 32, if there is one, are deactivated with the aid of the power control system disposed on the circuit board 26 so that the spring mechanism 10 turns both the electric motor 15 and the cam plate 11 back from the position equivalent to the opened state of the stabiliser 1 to the position equivalent to the closed state of the stabiliser and the locking members 13A and 13B are pushed back
14

into the locking indentations 18A and 18B of the catch plate 7.
In the event of interlocking of the vehicle axle fitted with the stabiliser 1, during which the two shafts 2 and 3 are turned towards one another and which is characterised by an angular offset between the locking members 13A and 13B and
the locking indentations 18A and 18B of the catch plate 7 such that the locking members 13 A and 13B can not be moved into the position in the locking indentations 18A and 18B indicated by reference number 13A_1 in Fig. 8, the electro-mechanical system or the stabiliser 1 is firstly moved into an only partially active state in the manner described above, i.e. the preparatory closed state.
When the stabiliser 1 is in the latter operating mode in which the stabihser 1 can not be activated, a sensor system likewise disposed on the circuit board 26 detects the current position of the motor output shaft 27 of the electric motor 15 and deactivates it, depending on the detected position of the cam plate 11. If the interlocking of the vehicle axle is reduced so that there is an angular offset of only up to a maximum of 1.25° between the two shafts 2 and 3 or between the locking member 13A respectively 13B and the locking indentation 18A respectively 18B, the locking members 13A and 13B are pushed into the locking indentations 18A and 18B of the catch plate 7 by means of the spring mechanism 17 and optionally with the assistance of the electric motor 15 which is then reactivated or powered, so that the coupling 40 is closed and the stabiliser 1 is activated again.
If the rotation angle between the two shafts 2 and 3 is bigger, the locking members 13A and 13B of the catch elements 12A and 12B can not be pushed into the locking indentations 18A and 18B of the catch plate 7, in which respect this should be taken as meaning rotation angles between the shafts 2 and 3 or between the locking indentations 18A and 18B and the locking members 13A and 13B in excess of 1.25°. In this case, the locking members 13A and 13B lie on the catch plate 7 as indicated by reference number 13 A_2 indicated in Fig. 8.
15

In this connection, it should be pointed out that the threshold angle of the maximum rotation angle between the two shafts 2 and 3 up to which the locking members can be respectively pushed into the co-operating locking indentations in the manner described above is correlated to a friction value factor depending on an opening angle of the relevant locking indentation in each case and resulting from the material pairing of the locking members and the catch plate, and the threshold angle mentioned above may therefore vary from the angular value of 1.25° mentioned above, depending on the respective application.
The electronic power system provided on the circuit board 26 for controlling the stabiliser 1 is provided with electronic amplifier elements in this instance, by means of which the signals of the Hall-effect sensors can be amplified. The electronic power system on the circuit board 26 is also provided with a separate control device, although this is not illustrated, which is connected to a CAN bus of the motor vehicle. The control device is supplied with information about the current speed of the vehicle via the CAN bus. If a predefined critical threshold speed is exceeded, the opened stabiliser 1 is locked by closing the coupling 40 so that the vehicle can be stabilised accordingly by the closed stabiliser 1 for the currently detected speed.
Finally, it should be pointed out that it lies within the scope of the person skilled in the art to provide the stabiliser proposed by the invention with only one catch element or with more than two catch elements, in which case whatever number of catch elements is selected will not change the way in which the embodiment of the
stabiliser 1 illustrated in the appended drawings as an example and explained in more detail in the foregoing description operates.
16

Reference numbers

1 Stabiliser
2 First shaft
3 Second shaft
4 Housing
5 Housing cover
6A,B Screws
7 Catch plate
8 Catch means
9 Drive source
10 Spring mechanism
11 Cam plate
12A,B Catch element
12A_1,12A_2 Lever arm
12B_1,12B_2 Lever arm
12A_1 A, 12A_2A, 12B_1A, 12B_2A Contact region
12A_2B, 12B_2B Lever part-arm
13A,B Locking member
13A_1,13A_2,13A_3,13A_4 Position of the locking member
14A,B Pivot point
15 Electric motor, drive source
16 Gear unit
17 Spring mechanism
18A,B Locking indentations
19A,B Narrowed regions
20A,B Flanks
21,22,23 Collar-type region
24 Bolt
25 Control groove
26 Circuit board
27 Motor output shaft
28 Other gear
29 Mount
31 External face of the catch plate
32 Retaining mechanism
40 Coupling
41 Control track
42 Gear
43 Splined region
17

WE CLAIM:
1. Stabiliser (1) for a motor vehicle with two shafts (2,3) extending in the vehicle transverse direction which can be coupled with one another by means of a mechanical coupling (40), which are respectively actively connected to tyres of the motor vehicle by their ends remote from the coupling (40), and a first shaft (2) is connected to a first coupling half provided in the form of a catch plate (7) and a second shaft (3) is connected to a second coupling half provided in the form of catch means (8) co-operating with the catch plate (7), and the catch means (8) comprises an actuatable catch element (12A, 12B) which can be driven by means of a drive source (9) against a spring mechanism (10) of a cam plate (11) which can be driven in rotation and a locking member (13A, 13B) joined to it, by means of which the shafts (2,3) are connected to one another so that they rotate in unison due to a non-positive connection between the catch plate (7) and the locking member (13A, 13B) when the cam plate (11) is in a first end position, and the non-positive connection is released when the cam plate (11) is in a second end position, characterised in that the catch element (12A, 12B) is provided with two lever arms (12A_l, 12A_2,12B_1,12B_2) rigidly joined to one another which have a common pivot point (14A, 14B), and the lever arms (12A_1, to 12B_2) are each provided with a contact region (12A_1 A, 12A_2A, 12B_1 A, 12B_2A) by means of which the lever arms (12A, 12B) make contact with the cam plate (11).
2. Stabiliser as claimed in claim 1, characterised in that the contact regions (12A_1 A to 12B_2A) of the lever arms (12A_1 to 12B_2) are of a curved design so that an at least approximately linear contact exists between the lever arms (12A_1 to 12B_2) and the cam plate (11).
3. Stabiliser as claimed in claim 1 or 2, characterised in that the locking member (13A, 13B) is provided in the form of a bolt fixedly connected to one of the lever arms (12A_1,12B_1).
18

Stabiliser as claimed in one of claims 1 to 3, characterised in that the catch plate (7) is connected to the first shaft (2) by means of a splined region (43).
Stabiliser as claimed in one of claims 1 to 4, characterised in that the catch plate (7) is provided with a locking indentation (18A, 18B) in which the locking member (13A, 13B) is disposed, preferably without any clearance, when the coupling (40) is in the closed state.
Stabiliser as claimed in claim 5, characterised in that the locking indentation (18A, 18B) is designed so that the coupling (40) can be closed by means of the spring mechanism (10) when an angular offset exists between the shafts (2, 3) which is smaller than a threshold angle correlated to an opening angle of the locking indentation (18A, 18B), which is preferably 1.25°.
Stabiliser as claimed in one of claims 1 to 6, characterised in that the cam plate (11) is mounted so as to be rotatable on the catch plate (7) and is connected to the drive source (9) and the spring mechanism (10) by means of a gear unit (16).
Stabiliser as claimed in one of claims 5 to 7, characterised in that the cam plate (11) is provided with an elliptical control track (41) provided with narrowed regions (19 A, 19B) in the region of the short half-axes and on which the lever arms (12A_1 to 12B_2) are guided by their contact regions (12A_1A to 12B_2A) so that the locking member (13A, 13B) is moved essentially radially outwards by reference to the catch plate (7) during a rotating movement of the cam plate (11) starting from a position equivalent to the closed state of the coupling (40) and is thus guided out of the locking indentation (18A, 18B) of the catch plate (7).
Stabiliser as claimed in one of claims 1 to 8, characterised in that the cam plate (11) is provided with collar-type regions (21,22,23) extending in certain
19

portions in the circumferential direction and two collar-type regions (22, 23) are provided as stops for a bolt (24) fixedly secured to the housing, and a control groove (25) is provided across a specific angular segment between the two stops (22, 23), in which the bolt (24) engages so that the cam plate (11) is disposed in one of the end positions when the bolt (24) is lying against one of the stops (22 or 23).
10. Stabiliser as claimed in one of claims 1 to 9, characterised in that the cam plate (11) is provided with an indicator unit which co-operates with position detecting sensors so that a current position of the cam plate (11) can be detected by means of the position detecting sensors.
11. Stabiliser as claimed in claim 10, characterised in that the position detecting sensors are provided in the form of Hall-effect sensors.
12 Stabiliser as claimed in one of claims 1 to 11, characterised in that the drive source (9) and the spring mechanism (10) are disposed in at least certain regions of the second shaft (3) provided in the form of a hollow shaft
13. Stabiliser as claimed in one of claims 1 to 12, characterised in that the spring mechanism (10) is provided with a helical spring (17) in the fitted position, which is tensed so that the cam plate (11) is activated in a direction closing the coupling (40).
14 Stabiliser as claimed in one of claims 1 to 13, characterised in that the drive source (9) is provided with an electric motor (15).
15. Stabiliser as claimed in one of claims 1 to 14, characterised in that the lever arm (12A_1,12B_1) of the catch element (12A, 12B) connected to the locking member (13A, 13B) has a lever part-arm (12A_2B/ 12B_2B) extending parallel therewith.
20

16. Stabiliser as claimed in one of claims 1 to 15, characterised in that the active connection between the cam plate (11) and the spring mechanism (10) is provided with a retaining mechanism (32) so that the cam plate (11) can be held in the current position opposing the spring force of the spring mechanism (10).
17. Stabiliser as claimed in claim 16, characterised in that the retaining mechanism (32) is provided in the form of a brake acting on the rotor of the electric motor (15).
18. Stabiliser as claimed in one of claims 10 to 17, characterised in that the position detecting sensors are disposed on a circuit board (26), on which other electronic components for amplifying the signals of the position detecting sensors are disposed.
19. Stabiliser as claimed in one of claims 10 to 18, characterised in that the circuit board (26) is provided with a control device connected to a CAN bus of the motor vehicle, so that the coupling (40) is closed as a function of a control device activation when a critical driving speed is exceeded.
21
Dated this 12th day of January, 2007

Abstract
A stabiliser for a motor vehicle with two shafts extending in the vehicle transverse direction which can be coupled with one another by means of a mechanical coupling (40), which are respectively actively connected to tyres of the motor vehicle by their ends remote from the coupling (40). A first shaft is connected to a first coupling half provided in the form of a catch plate and a second shaft is connected to a second coupling half provided in the form of catch means (8) co-operating with the catch plate. The catch means (8) comprises an actuatable catch element (12A, 12B) which
can be driven by means of a drive source (15) against a spring mechanism of a cam plate (11) which can be driven in rotation and a locking member (13A, 13B) joined to
it, by means of which the shafts are connected to one another so that they rotate in unison due to a non-positive connection between the catch plate and the locking member (12A, 12B) when the cam plate (11) is in a first end position, and the non-positive connection is released when the cam plate (11) is in a second end position. For the purpose of the invention, the catch element (12A, 12B) is provided with two lever arms (12A_1,12A_2,12B_1,12B_2) rigidly joined to one another, each of which is provided with a contact region (12A_1A, 12A_2A, 12B_1A, 12B_2A) by means of which the lever arms (12A_1,12A_2,12B_1,12B_2) make contact with the cam plate (11).
To
The Controller of Patents
The Patent Office
Mumbai
22

Documents:

67-mumnp-2007-abstract(granted)-(23-5-2008).pdf

67-mumnp-2007-abstract.doc

67-mumnp-2007-abstract.pdf

67-mumnp-2007-claims(granted)-(23-5-2008).pdf

67-mumnp-2007-claims.doc

67-mumnp-2007-claims.pdf

67-mumnp-2007-correspondence(21-5-2008).pdf

67-mumnp-2007-correspondence(ipo)-(20-5-2009).pdf

67-mumnp-2007-correspondence-others.pdf

67-mumnp-2007-correspondence-received.pdf

67-mumnp-2007-description (complete).pdf

67-mumnp-2007-description(granted)-(23-5-2008).pdf

67-mumnp-2007-drawing(granted)-(23-5-2008).pdf

67-mumnp-2007-drawings.pdf

67-mumnp-2007-form 1(4-42007).pdf

67-mumnp-2007-form 2(granted)-(23-5-2008).pdf

67-mumnp-2007-form 2(title page)-(15-1-2007).pdf

67-mumnp-2007-form 2(title page)-(granted)-(23-5-2008).pdf

67-mumnp-2007-form 26(3-5-2007).pdf

67-mumnp-2007-form 3(21-5-2008).pdf

67-mumnp-2007-form 5(21-5-2008).pdf

67-mumnp-2007-form-1.pdf

67-mumnp-2007-form-18.pdf

67-mumnp-2007-form-2.doc

67-mumnp-2007-form-2.pdf

67-mumnp-2007-form-3.pdf

67-mumnp-2007-form-5.pdf

67-mumnp-2007-form-pct-ib-301.pdf

67-mumnp-2007-form-pct-ib-304.pdf

67-mumnp-2007-pct-search report.pdf

67-mumnp-2007-specification(amended)-(21-5-2008).pdf

67-mumnp-2007-wo international publication report(15-1-2007).pdf

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Patent Number

220329

Indian Patent Application Number

67/MUMNP/2007

PG Journal Number

33/2008

Publication Date

15-Aug-2008

Grant Date

23-May-2008

Date of Filing

15-Jan-2007

Name of Patentee

ZF FRIEDRICHSHAFEN AG

Applicant Address

88038 FRIEDRICHSHAFEN

Inventors:

#	Inventor's Name	Inventor's Address
1	PETER REITZ	ZANNAU 2, 88099 NEUKIRCH
2	WOLFGANG KINZELMANN	BERGWEG 17, 88281 SCHLIER/HINTERMOOS
3	INGO MULLER	HERMANN-LONS-STRASSE 26, 97421 SCHWEINFURT
4	HANS-JURGEN MOSCH	FRIEDHOFSSTRASSE 3/1, 88069 TETTNANG
5	LUTZ PYDDE	IM WINKEL 15, 49401 DAMME
6	JENS VORTMEYER	AM BACHE 5, 32361 PREUSSISCH-OLDENDORF

PCT International Classification Number

B60G21/055

PCT International Application Number

PCT/DE05/001180

PCT International Filing date

2005-07-05

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	102004032744.0	2004-07-07	Germany