Control lever fixing mechanism

Abstract: In a control lever fixing mechanism, a shift lever (1) and a shaft (6) are inserted into through-holes of two side plates of a control lever (4). A lockup plate (15) is inserted into a space defined by the two side plates of the control lever. The shaft (6) and the shift lever (1) are pulled upward by screwing a nut (18) to a bolt (17) of the lockup plate (15) from the outside of the control lever. Thereby, the shift lever, the shaft and the control lever are brought into close contact with one another and fixed firmly as a unit, preventing angle deviation relative to each other.

Description: BACKGROUND OF THE INVENTION 1. Field of the invention The present invention relates to a control lever fixing mechanism employed in an automotive column AT (automatic transmission) shift lever device, to a column AT shift lever device including such a mechanism and to a vehicle having such a shift lever device. 2. Description of the Related Art In conventional column AT shift lever devices, a turning movement of the shift lever is transmitted to a control lever to operate a control cable. In a column AT shift lever device in which the control lever is disposed coaxially with the shift lever, there is a requirement that that the control lever be firmly fixed to the shift lever so that an angle deviation will not occur between the shift lever and the control lever. To meet the requirement, the control lever and the shift lever are conventionally formed into a single unit by casting or the like. However, this art has a problem in that the entire size is increased and, therefore, the weight is increased, in order to achieve a necessary strength. To solve the problem, a control lever fixing mechanism has been developed as shown in Fig. 7 wherein a base portion of a control lever 51 is split into two portions that are tightened by a bolt 54 after a shift lever 52 and a shaft 53 are inserted between the split portions. However, the mechanism shown in Fig. 7 has problems in that the fastening torque varies and the abutting surfaces of the control lever 51 and the shaft 53 are not stable. Moreover, a mechanism wherein the control lever is fastened simply from the outside as shown in Fig. 7, is not able to solve the problems of unstable fastening torque and unstable abutting surfaces, even if the abutting surfaces of the control lever 51 and the shaft 53 have non-circular sectional shapes. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a control lever fixing mechanism that solves the above-stated problems of the conventional art and makes it possible to firmly fix a control lever to a shift lever with a stable fastening torque and stable abutting surfaces, so as to prevent angle deviation of the control lever. According to the present invention, there is provided a control lever fixing mechanism as set out in claim 1. The shaft may have a non-circular section portion at each of its inner surface and its outer surface. The control lever fixing mechanism may further have a construction wherein an inner peripheral surface of the shaft has a non-circular sectional shape corresponding to the base portion outer surface of the shift lever, and wherein an outer peripheral surface of the shaft has a non-circular sectional shape, and opposite upper side surface portions of the outer peripheral surface of the shaft are flat and substantially symmetrically inclined. The base portion outer surface of the shift lever may include an upper flat surface, a flat opposite lower side surface portions. The lockup plate may be caused to move the shift lever upward by screwing of a nut onto a bolt provided in an upper portion of the lockup plate, from outside of the control lever. The lockup plate may comprise an annular body and the bolt may be provided integrally with an upper portion of the annular body. A bottom portion of the lockup plate may directly contact a bottom surface of the shift lever. An upper inner surface of each of the through-holes may include substantially symmetrical flat surface portions corresponding to an exterior shape of the shaft. In this specification, a direction in which the control lever is projected is termed upward direction, and the opposite direction is termed downward direction, for convenience in description. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and further objects, features and advantages of the present invention will become apparent from the following description of a preferred embodiment with reference to the accompanying drawings, wherein like numerals are used to represent like elements and wherein: Fig. 1 is an elevation of an entire column AT shift lever device incorporating a preferred embodiment of the present invention; Fig. 2 is a left side view of the column AT shift lever device shown in Fig. 1; Fig. 3 is a central longitudinal sectional view of portions of a control lever fixing mechanism according to a preferred embodiment; Fig. 4 is a sectional view of the control lever fixing mechanism taken on plane A-A of Fig. 3; Fig. 5 is a sectional view of the control lever fixing mechanism taken on plane B-B of Fig. 3; Fig. 6(A) is an elevation of a control lever; Fig. 6(B) is a side view of the control lever; Fig. 6(C) is a sectional view of the control lever taken on plane C-C of Fig. 6(A); and Fig. 7 is a sectional view of a conventional control lever fixing mechanism. DETAILED DESCRIPTION OF PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail hereinafter with reference to the accompanying drawings. A column AT shift lever device incorporating a control lever fixing mechanism according to this embodiment will first be described with reference to Figs. 1 and 2. A shift knob 2 is provided on a distal end of a shift lever 1. A base portion of the shift lever 1 is rotatably supported by a retainer 3. The retainer 3 is mounted near a steering column. A control lever 4 is connected so as to turn on the same axis as the shift lever 1 when the shift lever 1 is turned as indicated in Fig. 2. A control cable (not shown) is fixed to a distal end of a control lever 4, for shift operations of an automatic transmission, as in the conventional art. A control lever fixing mechanism according to this embodiment will be described with reference to Figs. 3-5 and 6(A)-6(C). Fig. 3 is a central longitudinal sectional view of portions of a control lever fixing mechanism according to the embodiment. Fig. 4 is a sectional view thereof taken on plane A-A of Fig. 3, and Fig. 5 is a sectional view taken on plane B-B of Fig. 3. Figs. 6(A)-6(C) illustrate a shape of a control lever alone, wherein Fig. 6(A) is an elevated view thereof, Fig. 6(B) is a side view, and Fig. 6(C) is a sectional view taken on plane C-C of Fig. 6(A). An outer surface of a base portion of the shift lever 1 is formed as a non-circular shape in section, as shown in Figs. 3-5. In this embodiment, an upper surface and right and left lower surfaces of the shift lever 1 are shaped as flat surfaces 5 as shown in Fig. 4. A shaft 6 is fitted onto an outer surface of the base portion of the shift lever 1. An inner surface of the shaft 6 is formed as a non-circular shape in section corresponding to the outer surface of the base portion of the shift lever 1 as shown in Fig. 4. The shaft 6 closely contacts substantially the entire length of the upper flat surface 5 of the shift lever 1. The outer surface of the shaft 6 is mostly formed as a cylindrical surface. The shaft 6 is rotatably supported by the retainer 3 as shown in Fig. 3. However, in locations of the sectional view of Fig. 4 taken on plane A-A of Fig. 3 and the sectional view of Fig. 5 taken on plane B-B of Fig. 3, the outer surface of the shaft 6 is formed into a non-circular shape in section. In particular, right and left side outer surfaces of an upper portion of the shaft 6 are formed as flat surfaces 7 symmetrically inclined. In the location of the plane A-A sectional view of Fig. 4, the shaft 6 has a shape wherein a lower half portion is eliminated. The control lever 4 is unitarily formed of a lever body 9 and a base portion 8 having an inverted-U shape in section on a plane in the direction of the axis of the base portion 8, as shown in Figs. 6(A)-6(C). The base portion 8 has a bottomless space 11 defined between two side plates 10, 10. Each of the two side plates 10, 10 has a through hole 12 for the shaft 6. An upper portion of an inner surface of each through hole 12 has symmetrical flat surface portions 13 corresponding to an exterior shape of the shaft 6. An upper planar portion connecting the two side plates 10, 10 has a bolt insert enlarged hole 14. According to this embodiment, the aforementioned component parts are combined with a lockup plate 15 for actual use. The lockup plate 15 is inserted into the bottomless space 11 of the control lever 4 from a bottom portion thereof as shown in Fig. 4. The lockup plate 15 is formed of an annular body 16 and a bolt 17 formed together with or firmly connected to an upper portion of the body 16. The annular body 16 is designed so that the shift lever 1 and the shaft 6 can be inserted into the annular body 16, and so that a bottomportion of the annular body 16 directly contacts a bottom surface of the shift lever 1. The bolt 17 of the lockup plate 15 is inserted into the bolt insert enlarged hole 14 of the control lever 4, and a nut 18 is screwed thereto from the outside of the control lever 4. The operation of the control lever fixing mechanism according to this embodiment will next be described. The control lever fixing mechanism is assembled by inserting the lockup plate 15 into the bottomless space 11 of the control lever 4, and then inserting the shift lever 1 and the shaft 6 into the lockup plate 15. By screwing and tightening the nut 18 to the bolt 17 of the lockup plate 15, a force occurs to pull the lockup plate 15 upward to the control lever 4 as indicated by the arrow in Fig. 4. As a result, the lockup plate 15 directly contacts the bottom portion of the shift lever 1 and pulls the shift lever 1 upward. Simultaneously, the shift lever 1 and the shaft 6 are brought into close contact with each other on the flat surfaces 5 as shown in Fig. 4, and thereby firmly connected as a unit. Therefore, the three component parts, that is, the shift lever 1, the shaft 6 and the lockup plate 15, are firmly fixed so that no rotation occurs relative to one another. In the location of the section shown in Fig. 5, the aforementioned force pulling the lockup plate 15 upward to the control lever 4 acts as a force that pulls the shaft 6 upward to the control lever 4, bringing the symmetrical flat surface portions 13 formed in the through holes 12 of the control lever 4 into close contact with the non-circular outer surface of the shaft 6. The control lever 4 is thereby firmly fixed to the shift lever 1 and the shaft 6. Therefore, the position of the control lever 4 at the time of a shift of the shift lever 1 to the parking position or the like can be precisely defined. As understood from the above description, in the control lever fixing mechanism according to this embodiment, the lockup plate 15 and the shift lever 1 are pulled upward by tightening the nut 18 so that the shaft 6 closely contacts the flat surface portions 13 of the control lever 4. Thereby the entire mechanism is assembled firmly as a unit. Therefore, the abutting surfaces of the control lever 4 and the shaft 6 become stable and the tightening torque on the nut 18 is stabilized. Furthermore, since the control lever 4 can be produced separately from the shift lever 1 and the shaft 6, there is another advantage that the weight can be reduced compared with the conventional art wherein the entire mechanism is cast as a unit. The invention also consists in a vehicle, e.g. a car, having the column AT shift lever mounted in it.

Claims: A control lever fixing mechanism comprising: a shift lever (1) having base portion with an outer surface of non-circular sectional shape; a shaft (6) fitted to the outside of the shift lever; and a control lever (4) fitted to the shaft; characterised by the control lever comprising at least two side plates (10) having a recess therebetween, the side plates having through-holes for the shaft, an upper inner surface of each of the through-holes including a flat surface portion (13) corresponding to an exterior shape of the shaft; and a lockup plate (15), inserted into the recess between the control lever side plates from an opening thereof, the lockup plate moving the shift lever (1) upward toward an upper portion of the recess and thereby causing the shift lever (1) to closely contact the shaft (6) and causing the shaft to closely contact the flat surface portions (13) of the control lever (4). A control lever fixing mechanism according to claim 1, wherein the shaft (6) has a non-circular section portion at each of its inner surface and its outer surface. A control lever fixing mechanism according to claim 2, wherein an inner peripheral surface of the shaft (6) has a non-circular sectional shape corresponding to the outer surface of the base portion of the shift lever, and wherein an outer peripheral surface of the shaft has a non-circular sectional shape, and opposite upper side surface portions (7) of the outer peripheral surface of the shaft are flat and substantially symmetrically inclined. A control lever fixing mechanism according to claim 3, wherein the outer surface of the base portion of the shift lever includes an upper flat surface portion (5), and flat opposite lower side surface portions (5). A control lever fixing mechanism according to any one of claims 1 to 4, wherein the lockup plate is caused to move the shift lever (1) upward by screwing of a nut (18) onto a bolt (17) provided at an upper portion of the lockup plate (15), from outside of the control lever. A control lever fixing mechanism according to claim 5, wherein the lockup plate (15) comprises an annular body and the bolt is provided integrally with an upper portion of the annular body. A control lever fixing mechanism according to claim 6, wherein a bottom portion of the lockup plate (15) directly contacts a bottom surface of the shift lever (1). A control lever fixing mechanism according to any one of claims 1 to 7, wherein at its upper inner surface each of the through-holes of the side plates (10) has substantially symmetrical flat surface portions (13) corresponding to the exterior shape of the shaft. A column automatic transmission shift lever device having a control lever fixing mechanism according to any one of claims 1 to 8. A vehicle having a column automatic transmission shift lever device according to claim 9.

Inventors: TAZAI AKIRA, TAZAI, AKIRA
Applicants: MANNOH KOGYO, MANNOH KOGYO CO., LTD.
Application year: 1997
Main classification: F16H59
IPC codes: F16H59, B60K20