The present invention relates to a gear shift lever assembly for a vehicle transmission, said assembly comprising a shift lever having a spherical portion, a housing to be fixed in a vehicle, a pivot bearing fixed in the housing for receiving the spherical portion to mount the shift lever for pivoting about a shift axis and about a select axis perpendicular to the shift axis, a rotation stop pin protruding from the surface of the spherical portion in a direction perpendicular to the select axis and to a longitudinal axis of the shift lever, a channel extending from the inner wall of the pivot bearing, which channel is configured to receive the rotation stop pin such that it prevents rotation of the shift lever about its longitudinal axis and such that it can move along the channel when the shift lever pivots about the select axis.

Such gear shift lever assembly is disclosed for example in US 5,592,856 A. The gear shift lever assembly comprises a shift lever having a spherical fulcrum ball portion which is received in a pivot bearing fixed in a housing of the assembly such that the shift lever is mounted for pivoting about a shift axis and about a select axis perpendicular to the shift axis. The fulcrum or spherical portion of the shift lever is provided with opposite rotation stop pins which extend from the spherical portion perpendicular to the longitudinal axis of the shift lever and perpendicular to the select axis. The pivot bearing which is formed as a cavity with the shape of a spherical ring complementary to the spherical portion is pro ^¬ vided with opposite recesses in its inner wall in the form of channels extending perpendicular to the select axis. The chan ^¬ nels are configured for receiving the rotation stop pins so that the rotation stop pins can travel along the channels when the shift lever is pivoted about the select axis. The channels receiving the rotation stop pins have width such that the rotation stop pins can slide along them but are essentially free of play in the width direction of the channels. These rotation stop pins within the channels block any rotational movement of the shift lever about its longitudinal axis. During pivotal movements of the shift lever about the shift axis the rotation stop pins perform a rotational movement within the associated channels. The gear shift lever assembly is further provided with springs, wherein after certain pivotal movement in select direction one of the rotation stop pins contacts one of the springs which is in turn compressed to provide a back to neu ^¬ tral force on the shift lever urging it back to the neutral position in select direction.

It is also known to arrange gear shift lever assemblies in such a manner that a detent feel is provided when the shift lever approaches and reaches a predetermined select position, for example if the shift lever is moved to the shift gate in ^¬ cluding the reverse gear. A gear shift lever assembly includ ^¬ ing a detent mechanism is for example described in US 2005/0172748 Al . A plunger is disposed outside of the cavity of the pivot bearing such that its tip is protruding through an opening in the inner wall of the pivot bearing. The spherical portion of the shift lever is provided with a recessed portion in the area where the plunger tip is located so that the plunger tip is not contacting the bottom of the recess over a certain portion of the select movement range of the shift lever. At one end the recess is provided with a raised bottom wall portion with a predetermined shape which is ar ^¬ ranged such that the plunger tip comes into contact with the surface of the raised bottom wall when it approaches a prede ^¬ termined select position of the shift lever. When the shift lever is approaching this raised portion the plunger tip slides along the rising surface of the raised portion which urges the plunger back against a bias spring force and which therefore creates a desired force profile when the shift lever approaches the predetermined shift position, the force profile depending on the profile of the raised bottom wall portion which determines the backward movement of the plunger against the bias force.

Whereas such detent mechanism is able to create a desired de ^¬ tent feel or engagement feedback to the driver when he moves the shift lever into the predetermined select position, it is a rather complicated mechanism with a spring bias and a move ^¬ able plunger which is cooperating with a complicated surface structure provided on the spherical portion of the shift lever .

It is an object of the present invention to provide a gear shift lever assembly having a detent feel or feedback at a predetermined select position of the shift lever generated by a detent mechanism which is of simple design with as little extra components needed as possible.

This object is achieved by the gear shift lever assembly com ^¬ prising the features of claim 1. Preferred embodiments are set out in the depended claims.

According to the present invention a detent mechanism is provided which generates a predetermined force profile when the shift lever is pivoted about the select axis towards a prede ^¬ termined select position, which detent mechanism is provided by a leaf spring which is disposed and arranged such that the rotation stop pin contacts the surface and slides along the surface of the leaf spring when the shift lever is approaching the predetermined position, wherein the leaf spring is shaped such that the rotation stop pin flexes the leaf spring when moving along its surface to create the detent feedback with the predetermined force profile. The force profile is deter- mined by the elastic flexure of the leaf spring caused by the rotation stop pin when is moves along the surface of the leaf spring .

According to the present invention the rotation stop pin which is present anyhow for providing the rotation stop function is utilized for a second function as a pin which cooperates with a leaf spring to create a desired counter-force profile when the shift lever approaches a predetermined select position, wherein the leaf spring is shaped to create the detent feel at the predetermined select position.

To provide this gear shift lever assembly with an effective detent mechanism according to the present invention only a single additional component is needed, namely the leaf spring. A leaf spring is a rather simple component that can be at ^¬ tached to the pivot bearing such that the rotation stop pin comes into contact with the leaf spring surface when the shift lever approaches the predetermined select position. The rota ^¬ tion stop pin then slides along the surface of the leaf spring which is shaped such that it creates a desired counter-force by flexing of the leaf spring and that it creates a detent feel when the shift lever reaches the predetermined select po ^¬ sition. In addition, the detent mechanism of the present invention does not require any component that is moveably mounted such as the spring biased plunger of the prior art mentioned .

In a preferred embodiment the rotation stop pin has a rounded tip portion which facilitates a smooth touchdown of the stop pin on the surface of the leaf spring.

In a preferred embodiment the leaf spring comprises a piece of sheet metal fixed at one end in the housing and freely pro- jecting therefrom to an opposite end extending into the channel .

In a preferred embodiment the leaf spring comprises a first portion disposed tangentially to the trajectory of the tip of the rotation stop pin when the shift lever approaches the pre ^¬ determined select position and the rotation stop pin first contacts the surface of the leaf spring, and an adjacent second portion disposed as a secant of the trajectory of the tip of the rotation stop pin when the shift lever gets closer to the predetermined select position. The first tangential portion further facilitates a smooth touchdown of the stop pin on the surface of the leaf spring with a low force exerted by the frictional contact when the stop pin slides along the first tangential portion of the leaf spring. The adjacent second portion of the leaf spring formed as a secant of the trajectory of the apex of the rotation stop pin causes an increased force transfer since the leaf spring has to be flexed when the stop pin slides along the second portion, wherein the precise shape of the second portion is chosen so that a de ^¬ sired force profile is resulting when the rotation stop pin slides along the second portion while flexing it to provide the desired detent feel.

The invention will be described in the following with reference to an embodiment shown in the drawings in which:

Fig. 1 shows a perspective view of a gear shift lever assem ^¬ bly;

Fig. 2 shows a plan view of the gear shift lever assembly from above ;

Fig. 3 shows a perspective view of a leaf spring which is used in the gear shift lever assembly; Fig. 4 shows a plan view of components of the gear shift lever assembly from above; and

Figs. 5a) to c) show schematical side views in cross-section of the gear shift lever assembly illustrating a sequence of states during a shift lever select movement.

As shown in Fig. 1 the gear shift lever assembly comprises a shift lever 2 which has a fulcrum ball or spherical portion 4 close to its lower end. The spherical portion 4 of the shift lever 2 is received in a pivotal bearing fixed in a housing 5 of the gear shift lever assembly. The pivotal bearing can for example, as shown in Fig. 5, include two opposite annular bushings 3 with curved inner walls complementary to the spherical portion 4 so that the shift lever 2 is pivotably mounted.

The spherical portion 4 of the shift lever 2 is provided with a rotation stop pin 8 (see Figures 5a) to c) ) which projects from the spherical portion in a direction perpendicular to the select axis and perpendicular to the longitudinal axis of the shift lever 2. The rotational stop pin 8 is received in a channel 6 extending from the pivotal bearing to the outside. The channel 6 has an inner width corresponding to the outer diameter of the rotational stop pin 8 so that the rotation stop pin 8 can be received therein such that channel 6 blocks rotational movements of the shift lever 2 about its longitu ^¬ dinal axis. On the other hand the rotational stop pin 8 can slide along channel 6 during select movements of the shift lever 2. A select movement of the shift lever 2 is for example shown in the sequence of Figures 5a) to c) in which the rota ^¬ tion stop pin 8 is pivoted vertically upward during a pivotal movement of the shift lever 2 in select direction (in the plane of Figures 5a) to c) ) . A leaf spring 10 is shown in a perspective view in Fig. 3. The leaf spring 10 is made of sheet metal and has a portion that is adapted for being mounted in the housing. The leaf spring 10 further has a projecting portion that is freely extending from the mounting portion and is arranged and dimensioned such that it extends into the channel 6 in which the rotational stop pin 8 is received. As can be seen in Figs. 5a) to c) the leaf spring 10 is shaped and arranged such that it extends with its freely projecting end portion into the channel 6 in such a manner that the tip of the rotational stop pin 8 comes into sliding contract on the surface of the leaf spring when it approaches a predetermined select position. This predeter ^¬ mined select position is illustrated in Fig. 5c) and can for example correspond to the select position of the shift lever 2 in a shift gate including the reverse gear.

The rotation stop pin 8 has a rounded tip portion 9. This fa ^¬ cilitates a smooth touchdown on the inner surface of the leaf spring 10 when the rounded tip portion 9 of the rotational stop pin 8 first comes into contact with the surface of the leaf spring 10 between the movement states shown in Figs. 5a) and b) .

The leaf spring 10 is arranged and shaped such that the rounded tip portion 9 of the rotational stop pin 8 when it first comes into contact with the surface of the leaf spring touches a first portion 12 at the freely projecting end of the leaf spring 10. This first portion 12 of the leaf spring is disposed tangentially to the trajectory of the tip 9 of the rotational stop pin when the shift lever approaches the prede ^¬ termined select position. Due to this tangential first portion 12 a smooth establishment of contact of the rotational stop pin on the leaf spring is achieved, whereas due to the tangen ^¬ tial arrangement of the first portion 12 the rotational stop pin can slide along this first portion 12 without creation of a significant counter-force by the leaf spring 10.

Adjacent to the tangential first portion 12 at the freely pro ^¬ jecting end of the leaf spring 10 is a second portion 14 of the leaf spring which is disposed as a secant of the trajecto ^¬ ry of the tip of the rotational stop pin 8 when the shift lev ^¬ er 2 gets closer to the predetermined select position. Due to this shape in the second portion 14 of the leaf spring further movement of the rotational stop pin 8 along the surface of the leaf spring in the area of the second portion 14 causes a flexing movement of the leaf spring 10 as indicated in Figures 5b) and c) . The leaf spring 10 is arranged such that it elas- tically flexes when the rotational stop pin is sliding along its surface when the shift lever 2 approaches the predeter ^¬ mined select position.

This flexure of the leaf spring 10 creates a counter-force on the rotational stop 8 and thus on the shift lever 2. The leaf spring 10 is shaped and arranged such that traveling of the tip of the rotational stop pin 8 along the surface portions 12 and 14 of the leaf spring creates the detent feedback on the shift lever 2 with the predetermined force profile.

The leaf spring 10 can also be shaped and arranged in such a manner that it creates a snap-in engagement feeling when the shift lever 2 reaches the predetermined select position.