The present invention relates to a shifter assembly for an au ^¬ tomatic vehicle transmission having a monostable shifter move ^¬ able from the monostable home position along a shift gate com ^¬ prising several subsequent straight sections along which the home position and transmission mode select positions reverse drive R, neutral N, and forward drive D are disposed.

A shifter assembly of this kind is known from DE 10 2006 059 992 Al . The shifter assembly comprises a monostable shift lev ^¬ er which, after being moved to a mode select position to select a particular mode of the transmission, automatically re ^¬ turns to a central or home position. The shift lever can be moved from the home position in a forward direction and in an opposite rearward direction (along the longitudinal direction of the vehicle) . Starting from the home position the shift lever is shifted along a first straight shift gate section to mode select position N, and from there along a second straight shift gate section which is collinear with the first straight shift gate section to mode select position D. In the opposite direction the shift lever can be moved in rearward direction along a third straight section to mode select position N, and from there along a fourth straight section to mode select po ^¬ sition R, wherein the third and fourth straight shift gate sections are collinear. The shift pattern of this shift gate is disadvantageous because there is a risk of skipping or overstepping mode elect position N. When the driver intends to move the shift lever from the home position to the mode select position N along the first straight shift gate section there is a risk that he or she skips or oversteps this mode select position N and continues to move the shifter in the same di ^¬ rection along the second straight shift gate section in the same direction towards mode select position D in a single con- tinuous movement step. Therefore, there is a risk that the driver unintentionally selects D or R when he was actually in ^¬ tending to move the shift lever to mode select position N.

Such shifter assemblies are employed in shift-by-wire shifters in which the mode select position to which the shifter is moved is sensed by a sensor arrangement and a corresponding signal is sent by a control unit to the transmission where it triggers an actuator to bring the transmission into the state corresponding to the sensed mode select position.

A further shifter assembly of the above described kind is dis ^¬ closed in US 2014/0013889 Al . This shifter assembly includes a shift lever that is movable in a shift gate which comprises two straight line portions (extending in longitudinal direc ^¬ tion of the vehicle) which are offset relative to each other in transverse direction, wherein a transversely extending (select direction) shift gate section is connecting the two straight line portions of the shift gate. The shift lever is a monostable lever which automatically returns to a home posi ^¬ tion located at the end of one of the straight line portions of the shift gate where this straight line portion of the shift gate is merging with the transversely extending shift gate section leading to the second straight line shift gate portion. From the monostable home position the shift lever is movable in the first straight line portion along a first straight shift gate section to mode select position N and from there further along a collinear second straight shift gate section to mode select position D. In order to shift to mode select position R the shift lever first has to be transversely moved from the home position in the first straight line shift gate portion to the second straight line shift gate portion, whereafter it is longitudinally moved along a third straight shift gate section to mode select position N and from there further in longitudinal direction along a fourth straight shift gate section collinear with the third shift gate section to mode select position R. The shift pattern of this shifter assembly is also problematic as regards operational safety. The reason is as already described above that, when the driver intends to shift to mode select position N, instead mode se ^¬ lect positions R or D is reached unintentionally in a single linear movement step when the intermediate mode select posi ^¬ tion N is inadvertently skipped or overstepped.

It is an object of the present invention to provide a shifter assembly for operating an automatic transmission of a vehicle which ensures operational safety and which minimizes the risk of unintentional shifting to forward or rearward driving states D or R.

This object is achieved by a shifter assembly comprising the features of claim 1. Preferred embodiments of the invention are set out in the dependent claims.

According to the present invention a first and a second straight shift gate section which is collinear with the first shift gate section extend in opposite directions from the home position of the monostable shift lever. At the end of the first and second straight shift gate sections remote from the home position a mode select position N is disposed. At the end of the first straight shift gate section remote from the home position the first straight shift gate section is connected to a third straight shift gate section which is not collinear with the first shift gate section. At the end of the third shift gate section remote from the first straight shift gate section mode select position D is disposed. Similarly, the se ^¬ cond straight shift gate section is at its end remote from the home position connected to a fourth straight shift gate sec ^¬ tion that is not collinear with the second straight shift gate section. At the end of the fourth straight shift gate section remote from the second straight shift gate section mode select position R is disposed.

The shifter assembly with this shift pattern is intuitively very clear and safe in operation. In particular, the shift pattern of shift lever movements to any of the available transmission states that can be selected by the shift lever is independent of the current mode selected for the transmission. Independently of the currently selected mode of operation of the transmission, the driver can shift to N by shifting the shift lever either along the first straight shift gate section to its end or in the opposite direction along the second straight shift gate section to its end. If the driver wants to shift to mode D the shift lever has to be moved from home po ^¬ sition along the first straight shift gate section to its end, and thereafter in a different direction along the second straight shift gate section to its end to reach D.

If the driver wants to shift to mode R the shift lever has to be moved from the home position along the second straight shift gate section to its end, thereby passing mode select po ^¬ sition N, and thereafter in a different direction along the fourth straight shift gate section to its end to reach mode select position R.

Due to this shift pattern according to the present invention the risk of unintended shift operations to D or R is consider ^¬ ably reduced. If the driver indeed wants to shift to mode se ^¬ lect position N the shift lever has to be moved either along the first or the second straight shift gate section to its end to reach N. Since there is no continuation of the first or se ^¬ cond straight shift gate section, the risk of skipping or overstepping mode selection position N is considerably reduced because it is located at the end of the respective straight shifting gate sections. It is very unlikely that the driver inadvertently or unintentionally changes the direction of movement of the shift lever at the end of the first or second straight shift gate sections. The shift lever can only be moved past mode select position N if the driver changes the direction of movement of the shift lever at the end of the first or second straight shift gate section into the direction of the third or fourth straight shifting gate section, respec ^¬ tively, to move the shift lever on to mode select position D or R, respectively. Due to the required change of direction of movement, because the first and second as well as third and fourth straight shift gate sections are not collinear, it is very unlikely that the mode select position N could be skipped or overstepped and the shift lever be moved on to D or R with ^¬ out intention. Therefore, the operational safety of the shift ^¬ er assembly comprising this shift pattern is considerably im ^¬ proved .

Furthermore, the shifter assembly can be operated by a driver very easily and in an intuitively clear manner. After the shifter assembly has been brought to a particular state by moving the shift lever to the particular mode select position, the shift lever returns to the monostable home position. Therefore, independently of the fact in which state the trans ^¬ mission currently is, the movement pattern of the shift lever to N, D or R is always the same, namely to N by a linear move ^¬ ment to the end of the first or second straight shift gate section, to D by moving the shift lever from the home position along the first straight shift gate section, changing direc ^¬ tion into the third straight shift gate section direction and moving it to the end of the third straight shift gate section to D; and to R by moving the shift lever from home position along the second straight gearshift section to its end, and then further changing direction into the fourth straight shift gate section and moving the shift lever to its end to R. Therefore, the movement pattern to any of the mode select po- sitions N, R, and D is always the same, whereas in current shifter assemblies with multi-stable shift levers the shift pattern to the intended target mode select position depends on the current position of the shift lever.

In a preferred embodiment the third straight shift gate sec ^¬ tion extends perpendicularly to the first straight shift gate section, and the fourth straight shift gate section extends perpendicularly to the second straight shift gate section. In this arrangement it is virtually impossible to inadvertently move the shift lever into the third or fourth straight shift gate section because a change of movement direction of 90° will not occur accidentally.

According to a preferred embodiment the third straight shift gate section extends parallel to, but in opposite direction relative to the fourth straight shift gate section. A shifter assembly with such shift pattern allows to distinguish between shifting to D and R in an intuitively clear manner. This is in particular so if the shifter assembly is according to a further preferred embodiment arranged to be mounted in the vehi ^¬ cle such that the first and second straight shift gate sec ^¬ tions extend in transverse direction and in that the third and fourth straight shift gate sections extend in longitudinal di ^¬ rection of the vehicle, and according to further preferred em ^¬ bodiment the third straight gear shift section extends in for ^¬ ward direction, and the fourth straight gear shift section extends in rearward direction of the vehicle. In this case mov ^¬ ing the shift lever forward along the third straight shift gate section brings the transmission to the state D, and mov ^¬ ing the shift lever in rearward direction along the fourth straight shift gate section brings the transmission to the state R. In a preferred embodiment the shift assembly comprises a sepa ^¬ rate input element for bringing the transmission to parking mode state P. If the transmission is brought to the parking mode state P by actuating the separate input element, the driver can shift to any of the modes R, N, and D by operating the shift lever as described above to move it along the shift pattern defined in the claims to the desired mode select posi ^¬ tion R, N or D.

The invention will now be described with reference to a pre ^¬ ferred embodiment shown in the drawings in which:

Fig. 1 is a schematical perspective view of a shifter assem ^¬ bly; and

Fig. 2 shows a schematic plan view of the shift pattern of the shifter assembly.

The shifter assembly 10 according to the invention is for example arranged on a console located between a driver seat and a passenger seat of a vehicle. The shifter assembly 1 compris ^¬ es a shift lever 8 and a housing 12 which has a panel surface 14 and which includes a shift gate 20 formed corresponding to the shift pattern of the shift lever 8. The shift lever 8 is mounted in the housing to be moveable along the shift pattern corresponding to the shift gate 20.

As can be seen from the schematic plan view of the shift pat ^¬ tern in Fig. 2 the shift pattern includes a monostable home position H, two neutral select positions N, forward drive se ^¬ lect position D, and rearward drive select position R. The shift lever assembly includes a mechanism that automatically returns shift lever 8 to home position H from any of the mode select positions N, R, D if the driver releases the shift lev ^¬ er at any of said mode select positions. As can be seen in the Figures the shift pattern comprises the monostable home position in the center. From this home posi ^¬ tion H a first straight gear shift section 1 extends, in this example to the right hand side, whereas a second straight shift gate section 2 extends in opposite direction from home position H, in this example to the left hand side. At the end of the first straight shift gate section 1 remote from home position H neutral select position N is disposed. In a symmet ^¬ ric manner, at the end of the second straight shift gate sec ^¬ tion 2 remote from home position H also a neutral select posi ^¬ tion N is disposed. The end of the first straight shifting gate section 1 remote from home position H is connected to a third straight shift gate section 3 which extends perpendicu ^¬ lar to the first shift gate section 1. At the end of the third shift gate section 3 remote from the first straight shifting gate 1 drive select position D is disposed. The wording that the end of the first straight shifting gate section remote is connected to a third straight shift gate section is intended to mean that there may also be a curved transitional shift gate portion between first and third straight shift gate sec ^¬ tions connecting these sections.

Similarly, the end of the second straight shifting gate sec ^¬ tion 2 remote from home position H is connected to a fourth straight shift gate section 4 which extends perpendicularly to the second straight shift gate section 2. At the end of the fourth straight shift gate section 4 remote from the second straight shift gate section 2 reverse select position R is disposed. Again, there may be a curved or bent shift gate por ^¬ tion connecting the second and fourth straight shift gate sec ^¬ tions .

The way of operation of the shifter assembly is now described with reference to Figs 1 and 2. It is assumed that the driver has shifted the transmission to neutral N by moving shift lev ^¬ er 8 from home position H to the end of the first straight shift gate section 1 to neutral select position N, which is sensed by a corresponding sensor arrangement in the housing of the shifter assembly which causes a corresponding signal to be sent by a control unit to the transmission to bring it to the neutral state. After the driver released shift lever 8 it re ^¬ turns to home position H. If the driver now wants to shift the transmission from N to D he or she moves the shift lever 8 from home position H along first straight shifting gate section 1 to the end thereof, and from there along third straight shift gate section 3 to the end thereof to reach forward drive select position D. When the driver then releases shift lever 8 it automatically returns to the home position H.

After some time with the transmission in state D the driver stops the vehicle and wants to shift to R. In order to do this he or she moves the shift lever 8 from monostable home posi ^¬ tion H along the second straight shift gate section 2 to the end thereof, and from there in a direction perpendicular to the second straight shift gate section 2 to and along a fourth straight shift gate section 4 to the end thereof to reach re ^¬ verse select position R. After the driver releases the shift lever 12 it returns to the monostable home position H and the transmission remains in R.

If the transmission is in state R or D, and the shift lever is moved from the monostable home position to the other one of R and D, the shift lever passes mode select position N on its way. The control unit can be arranged such that a signal is generated when the shift lever passes the intermediate state N to bring the transmission to N, or can be arranged such that the model select position signal is sent only based on the sensor information when the shift lever is released and starts to return to home position H; in this case no intermediate control signal to bring the transmission to N would be gener ^¬ ated when the shift lever is moved from R to D or from D to R.

It is clear from this description that, independently in which mode the transmission currently is, the shift lever 8 is in the monostable home position H so that any change of the transmission state the driver wants to perform starts with the shift lever 8 in the monostable home position H. It is also clear that the pattern of shift lever movements to D along first and third straight shift gate sections 1, 3 is always the same, regardless from which previous transmission state this shift operation to D as performed. The same applies to all shift lever movement patterns to R, N and D which are al ^¬ ways the same and do not depend on the current transmission state .

It will be appreciated that the shifter assembly according to the present invention can be operated in an intuitively clear manner and in a very safe manner. The operation is very safe because it is virtually impossible that a driver intending to move the shift lever to a neutral select position N is, when the shift lever reaches neutral select position N at the end of the first straight shift gate section 1, inadvertently or accidentally changes direction and moves the shift lever fur ^¬ ther along the third straight shift gate section 3. The same applies when the driver intends to move the shift lever to se ^¬ lect position N at the end of the second straight shift gate section 2.