WO2020234626A1

WO2020234626A1 - Override system for a gearshift assembly

Info

Publication number: WO2020234626A1
Application number: PCT/IB2019/054159
Authority: WO
Inventors: Niklas HEDSTRÖM; Andreas Hedlund
Original assignee: Ka Group Ag
Priority date: 2019-05-20
Filing date: 2019-05-20
Publication date: 2020-11-26
Also published as: EP3973212A1

Abstract

An override system for a gearshift assembly of a transmission of a vehicle includes a base having an index track including automatic and manual shifting gates and a selection gate extending between the shifting gates. The system also has a bi-stable shift lever coupled to a controller and pivotally mounted to the base and moveable within the index track across the selection gate between a first and second rest position. The shift lever is also moveable within the automatic shifting gate to select a park, reverse, and neutral condition to define a first state and to select a drive condition to define a second state. The system also includes a return mechanism coupled to the controller, with the controller directing the return mechanism to mechanically move the shift lever from the second to the first rest position when the system is in the first state.

Description

OVERRIDE SYSTEM FOR A GEARSHIFT ASSEMBLY

FIELD OF THE DISCLOSURE

[0001] The present disclosure relates generally to a gearshift assembly, and more particularly to an override system for a gearshift assembly for a transmission of a vehicle.

BACKGROUND

[0002] The present invention relates generally to a gearshift assembly for a transmission of a vehicle including a bi-stable shift lever which is pivotally mounted to a base for movement within an index track of the base in a select direction between a shifting gate for automatic mode (i.e., an automatic shifting gate or an automatic shifting lane) and a shifting gate for manual mode (i.e., a manual shifting gate or manual shifting lane) and for movement in a shifting direction perpendicular to the select direction within each of the shifting gates.

[0003] When in the automatic mode, the bi-stable shift lever is pivotally movable by a user in a shifting direction within the index track from a first rest position to a secondary position to select one of a park condition (P), a reverse condition (R), a neutral condition (N), a drive condition (D), or if present a low drive condition (L), which allows a coupled controller sensing such pivotal movement to direct the transmission to select the respective corresponding appropriate gear from a parking gear, a reverse gear, a neutral gear, a drive gear, and a low gear. Similarly, in the manual mode, the shift lever is pivotally movable by a user in the select direction from a second rest position to a secondary position to select between the corresponding multiple drive conditions (M), which allows a coupled controller sensing such pivotal movement to direct the transmission to select between multiple manual drive gears (such as four manual drive gears). The bi-stable shifter lever is also configured to automatically return to the respective first rest position in the automatic mode, or second rest position in the manual mode, in the absence of user force applied in the selection direction, while maintaining the shift lever in the respective selected condition in the automatic or manual mode.

[0004] Such gearshift assemblies also typically include a blocking element, which blocks the movement of the bi-stable shift lever within the automatic shifting gate from the first rest position to the secondary position unless actuated, with such actuation typically occurring where a user depresses the brake pedal. The movement of the blocking element, after actuation, to allow the shift lever to move in the select direction of the automatic shifting gate from the first rest position to the secondary position, results in the generation of sound associated with the movement of the blocking element. Such sound can be incorrectly perceived by the driver of the vehicle as being abnormal or a cause for concern.

[0005] It is thus an object of the present invention to provide a gearshift assembly that eliminates the sound associated with the movement of the blocking element in these gearshift assemblies by eliminating the use of a blocking element.

[0006] In addition, the use of the blocking element in such gearshift assemblies typically functions to prevent the selection movement of the bi-stable shift lever from the first rest position in the automatic mode to the second rest position in the manual mode unless the selected condition in the automatic mode is in the drive condition, in which the blocking element is moved to allow the selection movement to the manual shifting gate. The removal of this blocking element would thus eliminate the associated control of the movement of the bi-shift lever from the first rest position in the automatic mode to the second rest position in the manual mode unless the selected condition in the automatic mode is in the drive condition.

[0007] Accordingly, it is also an object of the present invention to provide an override system for controlling the selection movement of the bi-stable shift lever from the first rest position in the automatic mode to the second rest position unless the selected condition in the automatic mode is in the drive condition without the use of a blocking element.

SUMMARY

[0008] The present disclosure is directed to an override system for a gearshift assembly or a transmission of a vehicle having a bi-stable shifting lever moveable in an automatic shifting gate and a manual shifting gate.

[0009] The gearshift assembly includes a base having an index track including an automatic shifting gate and a manual shifting gate and a selection gate extending between the automatic shifting gate and the manual shifting gate. The gearshift assembly also includes a bi-stable shift lever pivotally mounted to the base and moveable within the index track across the selection gate between a first rest position within the automatic shifting gate and a second rest position within the manual shifting gate. The shift lever is moveable within the automatic shifting gate to select at least one of a park, reverse, and neutral condition to define a first state of the system, and is also moveable within the automatic shifting gate to select a drive condition to define a second state of the system. The override system for the gearshift assembly includes a return mechanism coupled to the bi-stable shift lever, and an electric motor coupled to the return mechanism. The override system for the gearshift assembly includes a controller coupled to the electric motor and to the shift lever to operate the return mechanism and mechanically move the shift lever from the second rest position within the manual shifting gate to the first rest position within the automatic shifting gate when the system is in the first state.

[0010] By providing a gearshift assembly without a blocking element, the present disclosure thus eliminates sound associated with the actuation and movement of the blocking element in gearshift assemblies including this feature. Further, the override system provided herein allows the user or operator to operate the vehicle in the manual mode when the shift lever has been moved to the second rest position from the first rest position when the system is in the second state.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The advantages of the present disclosure will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings. It is to be understood that the drawings are purely illustrative and are not necessarily drawn to scale.

[0012] Figure 1A is a perspective view of an override system for a gearshift assembly including a return mechanism with the shift lever in the automatic shifting gate and with the override system in the first state;

[0013] Figure IB is a perspective view of an override system for a gearshift assembly including a return mechanism with the shift lever in the manual shifting gate and with the override system in the second state;

[0014] Figure 2 is a partially exploded view of the gearshift assembly and index track of the override system of Figures 1A and IB;

[0015] Figure 3 is a perspective view of the index track of Figures 1A, IB and 2;

[0016] Figures 4 and 5 show perspective views of parts of the return mechanism of the override system of Figures 1A and IB;

[0017] Figures 6 to 8 show subsequent movements in which the return mechanism of the gearshift assembly performs a return operation of the shift lever from the manual shifting gate to the automatic shifting gate through the selection gate while the override system is in the first state. DETAILED DESCRIPTION

[0018] The present invention is directed to an override system 17 for a gearshift assembly 16 of a transmission for a vehicle 18. The vehicle 18 also includes a controller 19 coupled to the override system 17 and to the gearshift assembly 16 to control the operation of the vehicle 18.

[0019] The gearshift assembly 16, as best shown in Figure 1 and 2, includes a base 20 having an index track 21. The index track 21, as best shown in Figure 3 A, includes an automatic shifting gate 22 and a manual shifting gate 23 and a selection gate 24 extending between the automatic shifting gate 22 and the manual shifting gate 23. The gearshift assembly 16 also includes a bi-stable shift lever 30 electrically coupled to the controller 19 and pivotally mounted to the base 20 within the index track 21. In particular, the bi-stable shift lever 30 is pivotally moveable by the user within the index track 21 across the selection gate 24 in a selection direction between the automatic shifting gate 22 (see Figure 1A in which the shift lever is in the automatic shifting gate 22), corresponding to an automatic mode, and the manual shifting gate 23 (see Figure IB in which the shift lever is in the manual shifting gate 23), corresponding to a manual mode.

[0020] In addition, the bi-stable shift lever 30 is also pivotally moveable by the user along the automatic shifting gate 22 in a shifting direction transverse to the selection direction, from a first rest position 53 to a forward position 53A in a forward direction, or from the first rest position 53 in a rearward direction opposition the forward direction to a rearward position 53B (see Figure 3B for a schematic representation of the first rest position 53, forward position 53A, and rearward positon 53B), to select at least one of a park (P), reverse (R), neutral (N), drive (D) and low drive (L) condition (if present).

[0021] Still further, the bi-stable shift lever 30 is also pivotally moveable by the user along the manual shifting gate 23 in a shifting direction transverse to the selection direction, from a second rest position 55 in a forward direction to a forward position 55A, or in a rearward opposite the forward direction to the rearward position 55B (see Figure 3B for a schematic representation of the second rest position 55, forward position 55A, and rearward positon 55B) to select between one or more manual drive conditions M (shown as M1-M4 in Figure 3B, representing four manual drive conditions (Ml, M2, M3 and M4), and corresponding to the number of forward manual selectable gears in the transmission). While four manual drive conditions M1-M4 are illustrated in Figure 3B, the number of manual drive conditions M, corresponding to the number of forward manual selectable gears in the transmission of the vehicle 18, may vary between as little as two or as many as ten or more manual drive conditions, such as four or six or eight manual drive conditions.

[0022] The override system 17 for the gearshift assembly 16 further includes a return mechanism 51 coupled to the controller 19 that is configured to mechanically drive the shift lever 30 back to the first rest position 53 in the automatic shifting gate 22 from the second rest position 55 in the manual shifting gate 23 when the shift lever 30 has been placed in the manual shifting gate 23 by the user while the override system 17 is in a second state, as will be explained in further detail in Figures 6-8 below.

[0023] Referring now to Figure 2, the shift lever 30, here a plunger-type shift lever 30, includes a base portion 31 and an opposing selection portion 32 defining a length therebetween. The base portion 31 is in the form of a shaft that defines a length between a distal end 33 and a proximal end 34, with the proximal end 34 disposed within an inner cavity portion 35 of the selection portion 32. A sleeve 36 is fixed to the base portion 31 between the distal end 33 and proximal end 34. A spring 37 is coupled around the shaft of the base portion 31 and is partially disposed between the sleeve 36 and an end surface 38 of the selection portion 32. The spring 37 is configured to continually bias the base portion 32 of the shift lever 30 against an inner surface 40 of the index track 21 of the base 20. In certain embodiments, a selection member, shown as a push button 39, is coupled to the selection portion 32 of the shift lever 30 and is also electrically coupled to the controller 19.

[0024] In particular, when the shift lever 30 is positioned within the automatic shifting gate 22 (see Figures 1A and 8), the spring 37 applies force to the sleeve 36 to bias the base portion 31 of the shift lever 30 against an inner surface 43 of a first detent valley 42 of the automatic shifting gate 22. Similarly, when the shift lever 30 is positioned within the manual shifting gate 23 (see Figures IB and 6), the spring 37 applies force to the sleeve 36 to bias the base portion 31 of the shift lever 30 against an inner surface 45 of a second detent valley 44 of the manual shifting gate 23.

[0025] Yet still further, when the shift lever 30 is positioned along the selection gate 24 between the automatic shifting gate 22 and the manual shifting gate 23 (see Figure 7), such as wherein the shift lever 30 is moving from the automatic shifting gate 22 towards the manual shifting gate 23 or moving from the manual shifting gate 23 towards the automatic shifting gate 22, the spring 37 applies force to the sleeve 36 to bias the base portion 31 of the shift lever 30 against a raised inner surface 50 of the selection gate 24, corresponding to a crest between the first and second inner surfaces 43, 45 of the first and second detent valley 42, 44. This causes the proximal end 34 of the base portion 31 to move further within the inner cavity portion 35 in a direction away from the raised inner surface 50, which in turn causes the spring 37 to be further compressed between the end surface 38 of the selection portion 32 and the sleeve 36.

[0026] When the shift lever 30 is positioned within the automatic shifting gate 22, and due to the curved nature of the inner surface 43 of the first detent valley 42, the shift lever 30 is normally positioned in the first rest position 53 with the base portion 31 biased against the lowermost and centrally located valley portion 46 of the inner surface 43 in an upright position such that the length of the shift lever 30 is generally aligned with the length of the selection gate 24.

[0027] From the first rest position 53, the shift lever 30 can be pivotally moved by the user within the automatic shifting gate 22 in the shift direction transverse to the selection direction to the forward position 53 A or rearward position 53B, wherein the base portion 31 slides along, and remains biased against, an upwardly curving portion 47 of the inner surface 43 offset forward or rearward relative to the centrally located valley portion 46. The pivotal movement is interpreted by the controller 19 to select at least one of a park (P), reverse (R), neutral (N), drive (D) and low drive (L) condition (if present) defining the first state or second state of the override system 17.

[0028] The first state of the override system 17, as determined by the controller 19, is defined wherein the shift lever 30 has been positioned in the automatic shifting gate 22 and has selected one of the park (P), reverse (R), neutral (N), or low drive (L) (if present) conditions. Stated another way, the selection of one of the park (P), reverse (R), neutral (N), or low drive (L) (if present) conditions (see Figure 3B) defines the first state of the override system 17.

[0029] The second state of the override system 17, as determined by the controller 19, is defined wherein the shift lever 30 has been positioned in the automatic shifting gate 22 and has selected the drive (D) condition. Stated another way, the selection of the drive (D) condition defines the second state of the override system 17

[0030] In particular, the controller 19 is configured to sense and interpret the manual pivotal movement of the shift lever 30 in the automatic shifting gate 22 by the user from the first rest position 53 in the shifting direction forward to the forward position 53A, or rearward to the rearward position 53B, to alter the selection of one of the park (P), reverse (R), neutral (N), drive (D) and low drive (L) conditions to another different one of the park (P), reverse (R), neutral (N), drive (D) and low drive (L) conditions. Upon releasing the shift lever 30, and owing to the curved nature of the inner surface 43, the shift lever 30 is automatically returned to the first rest position 53 from either the forward position 53A or rearward position 53B while maintaining the newly selected operating condition (i.e., the newly selected one of the park (P), reverse (R), neutral (N), drive (D) or low drive (L) condition). The controller 19 thus confirms, based upon the newly selected operating condition, whether the override system 17 is in the first state or the second state.

[0031] By way of example, when the transmission is in the park (P) condition and in the first state, the user may pivot the shift lever 30 rearward once from the first rest position 53 to the rearward position 53B to select the reverse (R) condition, whereby the controller 19 senses the single pivoting movement to the rearward position 53B of the shift lever 30 and directs the gearshift assembly 16 to shift the transmission from the parking gear (corresponding to the park (P) condition) to the rearward gear (corresponding to the rear (R) condition while remaining in the first state), thereby allowing the user to operate the vehicle 18 to move (i.e., be driven) in a rearward direction. By way of a second example, when the transmission is in the park (P) condition, the user may pivot the shift lever 30 forward twice from the first rest position 53 to the forward position 53A to select the drive (D) condition, whereby the controller 19 senses the pivoting forward twice of the shift lever 30 and directs the gearshift assembly 16 to shift the transmission from the parking gear (corresponding to the park (P) condition) optionally through the neutral gear (corresponding to the (N) position) to the drive gear (corresponding to the drive (D) condition while moving from the first state to the second state), thereby allowing the user to operate the vehicle 18 to move (i.e., be driven) in a forward direction. The examples provided herein are representative of one possible shifting pattern for the vehicle 18, however any other shifting patterns, performed by the user in moving the shift lever 30 forward or rearward from the first rest position 53 to the forward position 53A or rearward position 53B between the park (P), reverse (R), neutral (N), drive (D) or low drive (L) condition are contemplated herein.

[0032] In certain embodiments, and as shown schematically in Figure 3B, the gearshift assembly 16 includes one or more automatic gate position sensors 85, which are each respectively coupled to the controller 19, and which are configured to sense the relative positioning of the shift lever 30 within the automatic shifting gate 22 (i.e., in the first rest position 53, forward position 53A, or rearward position 53B) and generate a signal corresponding to the relative positioning of the shift lever 30 that is received by the controller 19. The controller 19 is configured to interpret the received signal from the sensor(s) 85 to confirm that the shift lever 30 is in the first state or the second state and to also confirm the selection of the shift lever 30 in the newly selected one of the park (P), reverse (R), neutral (N), drive (D) or low drive (L) condition. More in particular, the sensors 85 are configured to generate a distinct signal that follows the movement of the shift lever 30 in the automatic shifting gate 22 corresponding to first rest position 53, forward position 53A, and rearward position 53B. The controller 19 then interprets each distinct signal to determine a desired user selection the newly selected one of the park (P), reverse (R), neutral (N), drive (D) or low drive (L) condition, and further determines whether the shift lever 30 is in the first state or the second state based upon the newly selected one condition.

[0033] Similarly, when the shift lever 30 is positioned within the manual shifting gate 23, and due to the curved nature of the inner surface 45 of the second detent valley 44, the shift lever 30 is normally positioned in the second rest position 55 with the base portion 31 biased against the lowermost and centrally located valley portion 49 of the inner surface 45 in an upright position such that the length of the shift lever 30 is generally aligned with the length of the selection gate 24. From the second rest position 55, and after the controller 19 confirms that the shift lever 30 is in the second state, explained in further detail below, the shift lever 30 can be pivotally moved within the manual shifting gate 23 by the user in the shift direction transverse to the selection direction to the forward position 55A or to the rearward position 55B, wherein the base portion 31 is biased against a upwardly curving portion 48 of the inner surface 45, to select one of the manual drive positions M (shown as M1-M4 in Figure 3B).

[0034] Similar to the automatic shifting gate 22, the manual shifting gate may include one or more sensors 85 which are each respectively coupled to the controller 19, and which are configured to sense the relative positioning of the shift lever 30 within the manual shifting gate 23 (i.e., in the second rest position 55, forward position 55A, or rearward position 55B) and generate a signal corresponding to the relative positioning of the shift lever 30 that is received by the controller 19. The controller 19 is configured to interpret the received signals from the sensors 85 in the manual shifting gate 30 to confirm whether the shift lever 30 has moved from the automatic shifting gate 22 to the manual shifting gate 23 while in the first state or the second state and to also confirm the selection of the shift lever 30 in the newly selected one of manual drive M conditions, such as a respective one of the Ml, M2, M3 or M4 manual drive conditions, when the shift lever 30 is in the second state and is moving in the shifting direction within the manual shifting gate 53.

[0035] If the controller 19 determines, via the signal received by the sensors 85 that the shift lever 30 has been moved to the second rest position 55 in the manual shifting gate 23 from the first rest position 53 of the automatic shifting gate 22 while in the first state, the controller 19 initiates the return mechanism 51, described in further detail below, to mechanically drive the shift lever 30 back to the automatic shifting gate 22, and in particular back to the first rest position 53 in the automatic shifting gate 22 through the selection gate 24. The controller 19 therefore does not allow the user to operate the vehicle 18 in the manual mode if the controller 19 determines that the override system 17 is in the first state.

[0036] Conversely, if the controller 19 determines, via the signal received by the sensors 85, that the shift lever 30 has been moved from the first rest position 53 in the automatic shifting gate 22 to the second rest position 55 in the manual shifting gate 23 while in the second state (i.e., wherein the shift lever 30 was in the drive (D) condition in the first rest position 53 in the automatic shifting gate 22 immediately prior to the pivoting movement of the control lever 30 in the selection direction by the user to the manual shifting gate 23), the controller 19 allows the user to operate the vehicle 18 within the manual shifting gate 23 in the manual mode to select one of the manual drive positions M (such as the Ml, M2, M3 or M4 drive conditions) to drive the vehicle 18 in the desired manual gear corresponding to the selected manual gear.

[0037] The second state is only available, as noted above, wherein the user has pivoted the shift lever 30 from the first rest position 53 in the automatic shifting gate 22 in the selection direction to the second rest position 55 in the manual shifting gate 23 when the shift lever 30 was in the drive (D) condition, and hence in the second state. If the user has pivoted the shift lever 30 from the first rest position 53 in the automatic shifting gate 22 in the selection direction to the second rest position in the manual shifting gate 23 when the shift lever 30 was in the reverse (R), neutral (N), park (P) or low drive (L) condition, and hence in the first state, the controller 19 senses such movement through the sensors 85 and activates the return mechanism 51 to mechanically drive the shift lever 30 back to the automatic shifting gate 24, as will be explained further below.

[0038] Referring now to Figures 4 and 5, the return mechanism 51 includes an electric motor 52 which drives a shaft 54 for rotation. The shaft 54 carries a worm 56. The worm 56 meshes with a worm gear 58. Worm 56 and worm gear 58 are preferably arranged such that a high gear ratio is achieved which allows to employ a rather small electric motor 52. In this manner the worm gear 58 can be driven to rotate by the electric motor 52.

[0039] On a front surface of the worm gear 58, a radial cam surface 68 and a helical cam surface 61 are formed. The radial cam surface 68 forms a side surface next to the worm gear 58, which side surface has a varying radial distance to the rotational axis of the worm gear 58, i.e., the side surface of the radial cam surface 68 is along a certain portion of the circumference closer to the rotational axis of the worm gear 58 than in the remaining portion of the circumference, as can best be seen in Fig. 4. The function of the radial cam surface 68 will be described in more detail further below.

[0040] The helical cam surface 61 is formed by the upper surface of a circular wall 62 which is coaxially surrounding the rotational axis of the worm gear 58. The helical cam surface 61 has a minimal height over the front surface of the worm gear 58 at a starting point. From the starting point in circumferential direction the height over the front surface of the worm gear 58 increases. Before reaching 360° in circumferential direction, the helical cam surface 61 has reached a maximal height over the front surface and then has a falling edge to return to the minimal height when the starting point is reached again.

[0041] A hollow plunger 70 is disposed coaxially with the rotational axis of the worm gear 58, and can be displaced in the direction of the rotational axis of the worm gear 58, but is fixed against rotation around the rotational axis of the worm gear 58. The plunger 70 is partially received within the circular wall 62 which provides the helical cam surface 61 at its upper surface. The plunger 70 is furthermore provided with a radial projection 72 that extends radially beyond the circular wall 62. The surface of the radial projection 72 facing the helical cam surface 61 comes into abutment on the helical cam surface 61. If the radial projection 72 is in a position such that it is in abutment with the helical cam surface, and when the electric motor is then activated to rotate the worm gear 58 in a direction such that the height of the helical cam surface 61 over the front surface of the worm gear 58 is increasing, plunger 70 is pushed along the axis of rotation and away from the worm gear 58 while the radial projection 72 slides upwards on the rotating helical cam surface 61.

[0042] A helical compression spring 90 is with one end received within the plunger 70 and is supported therein. The opposite end of the compression spring 90 supports a push member 60 which is facing a lower end portion of the shift lever, as can be seen in Figures 1A. IB, and 6-8.

[0043] When the return mechanism 51 is started by activating the electric motor 52, worm gear 58 starts to rotate. This causes that the radial projection 72 of the plunger 70 moves relatively along the helical cam surface to increasing heights over the front surface of the worm gear 58. In this manner, the plunger 70 is pushed to move in the direction of the axis of rotation of the worm gear 58 and towards the shift lever 30. When the push member 60 reaches the base portion 31 of the shift lever 30, and the plunger 70 is further moved towards the shift lever 30 by further rotation of the helical cam surface 61 towards the maximal height of the helical cam surface 61 over the front surface of the worm gear 58, the push member 60 acts on the base portion 31 of the shift lever 30 to move it back towards the automatic shifting gate 22 in the selection direction through the selection gate 24.

[0044] In Figures 6-8, such a return operation of the return mechanism 51 is shown as a sequence of moving states.

[0045] In the state shown in Figure 6, the shift lever 30 is in the manual shifting gate 22 in the second resting position 55 corresponding to the centrally located valley portion 49 of the inner surface 45 of the second detent valley 44 and is in the second state. The return operation has been started wherein the controller 19 (after confirming the override system 17 is in the second state and after confirming the positioning of the select lever 30 in the manual shifting gate 23) activates the electric motor 52 of the return mechanism 51, which causes rotation of the worm gear 58, which in turn causes a rotation of the helical cam surface 61 which rotates relatively to the radial projection 72 of plunger 70 such that the helical cam surface 61 which is in abutment with the radial projection 72 of the plunger 70 increase in height over the front surface of the worm gear 58. This causes plunger 70 to be pushed towards the shift lever 30, together with spring 90 and push member 60 (leftward as shown in Figure 6) until push member 60 comes into abutment with the surface of the shift lever 30. The force of the preloaded compression spring 90 on the push member 60 is sufficient to move push member 60 such that shift lever 30 begins rotation and is pushed toward the selection gate 24 (the rotation of the shift lever 30 is shown by arrow 93). The pushed movement of the shift lever 30 causes the base portion 31 to begin to travel along the inner surface 45 of the second detent valley 44 from the centrally located valley portion 49 of the inner surface 45 towards the raised inner surface 50 of the selection gate 24 as it rotates as shown by arrow 93, which causes the spring 37 to begin to compress between the end surface 38 of the selection portion 32 and the sleeve 36 to accommodate such movement.

[0046] Next, as shown in Figure 7, the continued operation of the electric motor 52 further rotates the worm gear 58 to increase the plunger 70 height and further push the push member 60 on the base portion 31 of the shift lever 30. The continued pushed movement of the shift lever 30 causes the base portion 31 to travel from the inner surface 45 of the second detent valley 44 and onto the raised inner surface 50 of the selection gate 24, which causes the spring 37 to begin further compress between the end surface 38 of the selection portion 32 and the sleeve 36 to accommodate such movement and to bias the base portion 31 against the raised inner surface 50. The shift lever 30 continues the rotational movement 93 during this operation.

[0047] Finally, as shown in Figure 8, the continued operation of the electric motor 52 further rotates the worm gear 58 to increase the plunger 70 to its maximum height and further push the push member 60 on the base portion 31 of the shift lever 30 in the selection direction from the raised inner surface 50 of the selection gate 24 towards the automatic shifting gate 22. Upon reaching the transitional point to the inner surface 43 of the automatic shifting gate 24, or wherein the base portion 41 extends beyond the crest of the raised inner surface 50, the natural curvature of the raised inner surface 50 and the inner surface 43 of the first detent valley 42 aids in moving the base portion 31 to the first rest position 53 corresponding to the centrally located valley portion 46 of the inner surface 43 of the first detent valley 42. During this movement, the spring 37 decompresses between the end surface 38 of the selection portion 32 and the sleeve 36 to accommodate such movement and to bias the base portion 31 against the inner surface 43 of the first detent valley 42, and eventually against the centrally located valley portion 46 of the inner surface 43 of the first detent valley 42.

[0048] Upon completion of the return operation, the worm gear 58 has been rotated to a position in which the radial projection 72 of plunger 70 has passed the area of maximal height of the helical cam surface 61 and is disposed opposite to the starting position of the helical cam surface 61 again, i.e. the region of minimal height of the helical cam surface 61 above the front surface of the worm gear 58. In this position, the push member 60 and the plunger 70 are free again to be moved back (shown as rightward by arrow 99 in Figure 8).

[0049] Upon completion of the return operation, the shift lever 30, now positioned within the automatic shifting gate 22 in the first rest position 53 with the distal end 33 of the base portion 31 biased against an inner surface 43 of a first detent valley 42, is maintained in the first state in the same one of the park (P), reverse (R), neutral (N), drive (D) and low drive (L) conditions that the shift lever 30 was in prior to the manual movement.

[0050] In further embodiments, wherein the select lever 30 includes a selection member such as a push button 39, the return mechanism 51 can also be utilized by the user in conjunction with the selection member 39 to automatically return the shift lever 30 from the second rest position 55 in the manual shifting gate 23 to the first rest position 53 in the automatic shifting gate 24, when the override system 17 is in the second state without having to manually pivot the shift lever 30.

[0051] In particular, when the shift lever 30 is in the manual selection gate 23 and in the second state (such as, for example, wherein the user is in first gear corresponding to the first manual drive position (Ml) and wherein the vehicle 18 is stopped or parked), the user moves the selection member 39 from a non-actuated position to an actuated position, such as by depressing the push button 39. The controller 19 senses the movement of the selection member 39 to the actuated position, and initiates the return operation with the return mechanism 51 in exactly the same manner as provided above in Figures 6 to 8.

[0052] The invention has been described in an illustrative manner, and it is be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. It is now apparent to those skilled in the art that many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that the invention may be practiced otherwise than as specifically described.

Claims

CLAIMS What is claimed is:

1. An override system for a gearshift assembly of a transmission of a vehicle, said override system comprising:

a base having an index track including an automatic shifting gate and a manual shifting gate and a selection gate extending between said automatic shifting gate and said manual shifting gate;

a bi-stable shift lever pivotally mounted to said base and moveable within said index track across said selection gate between a first rest position within said automatic shifting gate and a second rest position within said manual shifting gate, and said shift lever moveable within said automatic shifting gate to select at least one of a park, reverse, and neutral condition to define a first state of said system, and moveable within said automatic shifting gate to select a drive condition to define a second state of said system;

a return mechanism coupled to said bi-stable shift lever;

an electric motor coupled to said return mechanism; and

a controller coupled to said electric motor and to said shift lever to operate said return mechanism to mechanically move said shift lever from said second rest position within said manual shifting gate to said first rest position within said automatic shifting gate when said system is in said first state.

2. The override system of claim 1, wherein said shift lever is moveable within said automatic shifting gate to further select a low gear condition, and wherein said low gear condition further defines said first state of said system.

3. The override system of claim 1, wherein said controller allows said shift lever to remain in said manual shifting gate when said system is in said second state.

4. The override system of claim 3 further comprising a selection member coupled to said controller and selectable between an actuated position and a non-actuated position, wherein said controller operates said return mechanism to mechanically move said shift lever from said second rest position within said manual shifting gate to said first rest position within said automatic shifting gate when said selection member is in said actuated position and when said system is in said second state.

5. The override system of claim 4, wherein said selection member is coupled to said shift lever.

6. The override system of claim 4, wherein said selection member comprises a push button moveable between a depressed position corresponding to said actuated position and a non-depressed position corresponding to said non-actuated position, and

wherein said controller operates said return mechanism to mechanically move said shift lever from said second rest position within said manual shifting gate to said first rest position within said automatic shifting gate when said selection member is in said depressed position.

7. The override system of claim 1 further comprising a sensor coupled to said controller for generating a manual gate positioning signal when the shift lever is positioned within said manual shifting gate,

wherein said controller operates said return mechanism to mechanically move said shift lever from said second rest position within said manual shifting gate to said first rest position within said automatic shifting gate upon receipt of said generated manual gate positioning signal and when said system is in said first state.

8. The override system of claim 1 further comprising a sensor coupled to said controller for generating first state signal when said first state is selected,

wherein said controller operates said return mechanism to mechanically move said shift lever from said second rest position within said manual shifting gate to said first rest position within said automatic shifting gate upon receipt of said generated first state signal.

9. The override system of claim 1 further comprising:

a first sensor coupled to said controller for generating a manual gate positioning signal when the shift lever is positioned within said manual shifting gate;

a second sensor coupled to said controller for generating first state signal when said first state is selected;

wherein said controller operates said return mechanism to mechanically move said shift lever from said second rest position within said manual shifting gate to said first rest position within said automatic shifting gate upon receipt of said gemerated manual gate positioning signal and said generated first state signal.

10. A method for overriding the movement of a bi-stable shift lever of a gearshift assembly for a transmission of a vehicle, with the bi-stable shift lever mounted to a base having an index track including an automatic shifting gate and a manual shifting gate and a selection gate extending between the automatic and manual shifting gate, and with the gearshift assembly including a return mechanism coupled to the bi-stable shift lever, an electric motor coupled to said return mechanism, and a controller coupled to said electric motor, with the bi-stable shift lever moveable within the automatic shifting gate to select at least one of a park, reverse, and neutral condition to define a first state of an override system, and with the bi-stable shift lever moveable within the automatic shifting gate to a drive condition to define a second state of the override system, said method comprising:

determining if the override system is in the first state or the second state;

permitting movement of the shift lever between the manual and the automatic shifting gates;

determining if the shift lever is in the manual shifting gate or the automatic shifting gate; and

directing the electric motor to operate the return mechanism to mechanically act on the shift lever to move the shift lever from the manual shifting gate to the automatic shifting gate along a selection direction when the shift lever is in the manual shifting gate and when the override system is in the first state.

11. The method of claim 10, wherein said step of determining if the shift lever is in the manual shifting gate or the automatic shifting gate and said step of directing the electric motor comprise:

generating a first state signal when the shift lever is moved within the automatic shifting gate to select one of a park condition, a reverse condition, or a neutral condition; and

directing the electric motor to operate the return mechanism to mechanically act on the shift lever to return the shift lever from the manual shifting gate to the automatic shifting gate along a selection direction when the shift lever is in the manual shifting gate and upon receipt of said generated first state signal by the controller.

12. The method of claim 10, wherein said step of determining if the shift lever is in the manual shifting gate or the automatic shifting gate and said step of directing the electric motor comprise:

generating a manual gate positioning signal when the shift lever is positioned in the manual shifting gate; and

directing the electric motor to operate the return mechanism to mechanically act on the shift lever to return the shift lever from the manual shifting gate to the automatic shifting gate along a selection direction upon receipt of said generated manual gate positioning signal by the controller when the shift lever is in the first state.

13. The method of claim 10, wherein said step of determining if the shift lever is in the manual shifting gate or the automatic shifting gate and said step of directing the electric motor comprise:

generating a first state signal when the shift lever is moved within the automatic shifting gate to select one of a park condition, a reverse condition, or a neutral condition;

directing the electric motor to operate the return mechanism to mechanically act on the shift lever to return the shift lever from the manual shifting gate to the automatic shifting gate along a selection direction upon receipt of each of said generated manual gate positioning signal and said generated first state signal by the controller.

14. The method of claim 10, wherein gearshift assembly further includes a selection member coupled to the controller and selectable between an actuated and a non-actuated position, and wherein said method further comprises:

directing the electric motor to operate the return mechanism to mechanically act on the shift lever to move the shift lever from the manual shifting gate to the automatic shifting gate when the shift lever is in the manual shifting gate and when the selection member is in the actuated position.