Shifter assembly

Abstract: A shift lever assembly is provided including a cylindrical member (24) having a fixed axis. An annular member (22) is supported for rotation about the axis of the cylindrical member. A lever (12) is connected to the annular member and is moveable within a first shift lane (16) and a second shift lane (20) substantially parallel the first shift lane. The second lane (20) is connected to the first lane (16) by a bisecting lane (18). A compliant member (28) is provided to move the lever (12) from the first lane (16) to the second lane (20). The compliant member (28) is provided between the cylindrical member (24) and annular member (22).

Description: The present invention relates to a shifter assembly for a motor vehicle having a lateral shift plane and a longitudinal shift plane, and more particularly to such a shift mechanism for a manual transfer case in a four-wheel drive motor vehicle. Manual transfer cases include a shift pattern that typically includes a longitudinal plane and a lateral plane to prevent accidental shifting into an undesired drive range (such as into 4 wheel low). Various devices have been devised to provide a lever which enables these movements in the longitudinal and lateral planes. These devices are complicated and comprised of several pieces including a pair of linkages and a resilient connection for returning the lever to a centred position. An example of such a device is illustrated in U.S. Patent 5,398,565, to Broek ('565 patent). As illustrated in Figure 6 of the `565 patent, the shift lever moves longitudinally by rotating about a bolt 68. The lever rotates about a shoulder pivot pin 68. A spring 110 is compressed within a pocket 106 to bias a plunger 108 against a protrusion 76 to bias the lever set assembly counterclockwise about the pivot pin 100 relative to the actuator 26 as shown in Figure 2. This and other prior art shift lever assemblies were constructed from several parts which increases the price of the assembly, increases the likelihood of failure of one of the parts, and due to the stack-up of the tolerances of the parts, creates a potential for the system to not operate as desired. Furthermore, the biasing means comprises a spring which typically varies considerably in manufacture and often results in undesired shifting efforts. It would therefore be desirable to provide a shift lever assembly made from fewer pieces and having a reliable biasing means. EP-A- 0 289 754 discloses a shift lever assembly including a shift lever connected to a sleeve supported for rotation about the axis of a bolt. A flexible bushing is provided between the bolt and the sleeve. The shift lever assembly is intended for a PRNDL shift mechanism of an automatic transmission and includes a detent pin located on the shift lever that is biased upwardly into contact with a linear cam surface formed with detent grooves. As the lever pivots, the pin alternately enters and leaves the detent grooves, each of which corresponds to one of the PRNDL positions of the lever. It is an object of the present invention to provide a shift lever assembly made from fewer pieces and having a reliable biasing means. Accordingly, a shift lever assembly according to he present invention comprises; a bolt having a fixed axis, a sleeve supported for rotation about the axis of the bolt, a shift lever connected to the sleeve, and a flexible bushing (28) provided between the bolt and the sleeve, characterised in that; the shift lever assembly is connected to shift a manual transfer case of a motor vehicle capable of being shifted between ranges of four wheel drive operation, the shift lever is moveable in first and second mutually parallel longitudinal shift lanes and in a third lateral shift lane connecting the first and second shift lanes, the shift lever is moveable in the first shift lane between a first plurality of shift selection positions and in the second shift lane between a second plurality of shift selection positions, and the bushing has a compliance which enables the sleeve to rotate out of alignment with the bolt axis to a second axis when the shift lever is moved in the third lateral shift lane to select between the first and second plurality of shift positions, such movement in the third lateral shift lane being resisted by the compliance of the bushing. It is thus an object of the present invention to provide a shift lever assembly made from fewer pieces and having a reliable biasing means. Accordingly, a shift lever assembly according to the present invention includes a cylindrical member having a fixed axis. An annular member is supported for rotation about the axis of the cylindrical member. A lever is connected to the annular member and is moveable within a first shift lane and a second shift lane substantially parallel the first shift lane. The second lane is connected to the first lane by a bisecting lane. A compliant member is provided to move the lever from the first lane to the second lane. The compliant member is provided between the cylindrical member and annular member. The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an isometric view of a transfer case shifter according to the present invention; Figure 2 is a partial front view of the shifter assembly shown in Figure 1; Figure 3 is a partial side view of the shifter assembly shown in Figure 1; and Figure 4 is a plan view of the shifter assembly shown in Figure 1. Referring first to Figure 1, a shifter assembly 10 includes a shift lever 12 for travelling in a shift gate 14. The shift gate 14 includes a first longitudinal lane 16 traversed by a lateral lane 18 connected to a second longitudinal lane 20. The shift gate 14 includes several positions, including a two-wheel drive position, a four-wheel drive high position, and a four-wheel drive low position. A neutral position may also be established within the shift gate 14. The lateral lane 18 prevents unintentional shifting from the first longitudinal lane 16 to the second longitudinal lane 20 when shifting the lever fore/aft, thereby preventing unintentional shifting into an undesired range, which might otherwise occur during an such a shift. The shift lever 12 is connected to a cylindrical member 22 supported for rotation about a shoulder bolt 24 having an axis 26. The bolt 24 is preferably fixed to the transfer case 25. Thus, as the lever 12 is moved longitudinally in the first lane 16 or the second lane 20, the sleeve 22 rotates about the axis 26 of the bolt 24. A bushing 28 is provided between the cylindrical member 22 and bolt 24. The bushing 28 is preferably made from a rubber or nylon material. This bushing 28 isolates the members from relative movement and thereby prevents noise from vehicle vibrations. More significantly, the bushing 28 has a compliance which enables the cylindrical member 22 to rotate out of alignment with the axis 26, as best viewed in Figure 2, to a second axis 27. During this movement, the shift lever 12 is moved in the lateral lane 18. The cylindrical member then lies in a second axis 27 intersecting the first axis 26. During this movement, the bushing 28 is compressed so that the cylindrical member 22 is no longer coaxial with bolt 26. The lever 12 is then permitted to move longitudinally in the shift gate 14 as the cylindrical member 22 rotates about the bolt 24 and thereby move in the second longitudinal lane 20. As best viewed in Figure 3, the bushing 28 preferably includes a pair of arcuate slots 29, 31 which extend through the bushing 28 along the axis 27 thereof. The arcuate slots 29, 31 are preferably provided above and below the axis 27 as illustrated in Figure 3, to enable compression of the bushing 28 in the lateral lane and aid in tuning the shift effort to a comfortable level. As best viewed in Figure 4, the bushing 24 preferably includes a helical slit 33 to facilitate assembly over the shoulder bolt 24. The shifter assembly 10 further includes a link 30 attached to the cylindrical member 22. This link 30 is connected in a known manner to a cable or rod (not shown) attached to the transfer case to enable manual shifting thereof in a known manner. As shown in Figure 4, the shift gate 14 is formed in a plate 40 which is preferably fixed to the transfer case (not shown). The shift gate 14 includes a two-wheel drive position 41, a four-wheel high position 42, a neutral position 43, and a two-wheel drive low position 44. As described above, movement in the lateral lane 18 is resisted by the compliance of the bushing 28. In a manner known to one skilled in the art, when the lever 12 is moved to the neutral position 43, the transfer case driveably disconnects the engine from the drive wheels. In a preferred embodiment, this is done by driveably disengaging a planetary gearset in a manner known to one skilled in the art. As the lever 12 is moved to the four-wheel low position 44, the planetary gearset is shifted into a low range. In an alternative embodiment, as illustrated in Figure 3, a pin 72 projects from the shift lever 12, parallel the axis 26, and a cam is provided in which the pin follows as the cylindrical member 22 is rotated about the bolt 24. Instead of the lateral lane 18, the alternative embodiment includes a detent 74 in the cam 70. The pin 72, as it rotates to the detent 74, enables the lever 12 to be moved from a two-wheel drive to a four-wheel drive high mode. The lever 12 is depressed into a second lane 78 of the cam 70 to disengage the transfer case and thus achieve a neutral position. As the pin 72 is moved forward in the lower portion of the cam 78, a four-wheel low mode is engaged. The bushing 28 allows the cylindrical member 22 to be depressed perpendicular to the axis of the bolt 24. One skilled in the art recognises that the bushing 28 may be constructed to bias the lever 12 either to the first longitudinal shift lane 16, the second longitudinal shift lane 20, or a position in the lateral shift lane 18 intermediate the two longitudinal shift lanes 16, 20. Alternatively, the shift lever 12 travels in a shift gate 14 having an H-shape pattern as is known to one skilled in the art. Preferably, the lateral movement is performed against the compliance of the bushing and the fore/aft movement of the lever is performed rotationally against the bolt in a manner similar to that described above for the transfer case shifter. In a further alternative embodiment, the bolt 24 rotates about the axis 26 and the bushing 28 and cylindrical member 22 rotate therewith.

Claims: A shift lever assembly comprising; a bolt (4) having a fixed axis; a sleeve (22) supported for rotation about the axis of the bolt (4) ; a shift lever (12) connected to the sleeve (22); and a flexible bushing (28) provided between the bolt and the sleeve; characterised in that ; the shift lever assembly is connected to shift a manual transfer case of a motor vehicle capable of being shifted between ranges of four wheel drive operation; the shift lever is moveable in first and second mutually parallel longitudinal shift lanes (16,20) and in a third lateral shift lane (18) connecting the first and second shift lanes (16,20); the shift lever is moveable in the first shift lane (16) between a first plurality of shift selection positions (41,42) and in the second shift lane (20) between a second plurality of shift selection positions (43,44); and the bushing (28) has a compliance which enables the sleeve (22) to rotate out of alignment with the bolt axis (26) to a second axis (27) when the shift lever (12) is moved in the third lateral shift lane (18) to select between the first and second plurality of shift positions, such movement in the third lateral shift lane (18) being resisted by the compliance of the bushing (28) . A shift lever assembly according to claim 1, wherein the first plurality of shift selection positions (41,42) comprise a two-wheel drive position (41) and a four wheel drive position (42) and the second plurality of shift selection positions (43,44) comprise a neutral position (43) and a two wheel low position (44). A shift lever assembly according to claim 1 or 2, wherein the bushing (28) has a longitudinal arcuate slot (29,31) therein. A shift lever assembly according to claim 3, wherein the arcuate slot (29,31) is substantially parallel to said axis. A shift lever assembly according to any one of the preceding claims, wherein the bushing (28) is of a nylon or rubber material. A shift lever assembly according to any one of the preceding claims, wherein the bushing (28) further comprises a helical split (33). A method of providing a shift pattern for a shift lever assembly comprising a bolt (4) having a fixed axis (26); a sleeve (22) supported for rotation about the axis of the bolt (4); a shift lever (12) connected to the sleeve (22); and a flexible bushing (28) provided between the bolt and the sleeve; characterised in that ; the method is applied to a shift lever assembly connected to shift a manual transfer case of a motor vehicle capable of being shifted between ranges of four wheel drive operation, the method comprising the steps of; providing a shift gate for the shift lever enabling the shift lever to move in first and second mutually parallel longitudinal shift lanes (16,20) and a third lateral shift lane (18) connecting the first and second shift lanes (16,20), the shift lever being moveable in the first shift lane (16) between a first plurality of shift selection positions (41,42) and in the second shift lane (20) between a second plurality of shift selection positions (43,44); and arranging the bushing (28) to have a compliance which enables the sleeve (22) to rotate out of alignment with the bolt axis (26) to a second axis (27) when the shift lever (12) is moved in the third lateral shift lane (18) to select between the first and second plurality of shift positions, such movement in the third lateral shift lane (18) being resisted by the compliance of the bushing (28).

Inventors: COOK JAMES MICHAEL, COOK, JAMES MICHAEL
Applicants: FORD GLOBAL TECH LLC, FORD GLOBAL TECHNOLOGIES, LLC
Application year: 1999
Main classification: F16H59
IPC codes: F16H61, F16H59