Patent Publication Number: US-6904825-B2

Title: Shift control device for a transmission mechanism

Description:
This application is a divisional of U.S. application Ser. No. 09/413,877 filed Oct. 7, 1999, which became U.S. Pat. No. 6,532,842 on Mar. 18, 2003. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a shift control device for a transmission mechanism of a motor vehicle, and more particularly to a column-type shift control device. 
   2. Related Art 
   A column-type shift control device is now used on a part of motor vehicles equipped with an automatic transmission (AT) or a continuously variable transmission (CVT). In this shift control device, a shift control lever provided in the vicinity of a steering wheel is swung about a lever mounting axis or pulled up to thereby set a desired shift range. When compared with a floor-type shift control device, the column-type shift control device can help expand the effective space within a passenger compartment of a motor vehicle and improve the occupying properties thereof, much attention being thus paid to the latter. 
     FIG. 14  is a drawing explaining a conventional column-type shift control device. In the figure, reference numerals  1  and  2  denote a steering wheel and a shift control lever for column shifting, respectively. The steering wheel  1  is mounted on a steering shaft not shown, and the shift control lever  2  is mounted on a shift shaft not shown. The conventional shift control device is mounted such that an axis S 1  of the steering shaft is parallel with an axis of the shift shaft. Therefore, when the shift control lever  2  is swung (moved in a direction indicated by reference numeral d 1 ), the shift shaft rotates through an angle corresponding to a distance that the shift control lever is shifted. On the contrary, when the shift control lever  2  is pulled up toward the driver (moved in a direction indicated by reference numeral d 2 ), the shift shaft moves in the axial direction thereof a distance corresponding to a distance that the shift control lever is shifted. In other words, these mean that the shift control lever  2  has to be moved in the direction d 2  in order to move the shift shaft in the axial direction without rotating the same shaft, while the shift control lever  2  has to be moved in the direction d 1  in order to move the shift shaft axially without rotating the same shaft. 
   In the shift control device in which the shift shaft is disposed in parallel with the steering shaft as described above, when swing operating the shift control lever  2  to try to shift the transmissions, the driver tends to move the same lever in a direction indicated by reference numeral d 1 ′ which deviates from the direction d 1 . In addition, when pulling up the shift control lever  2 , the driver tends to move the same lever in a direction indicated by reference numeral d 2 ′ which deviates the direction d 2 . The reason for these deviations from the intended operating directions is because the driver tends to operate the shift control lever  2  with reference to a rotational center P of his or her shoulder. When thinking of swing operations by the driver, the driver tends to rotate the shift control lever  2  at a distance equal to a distance from the rotational center P of his or her shoulder to the shift control lever  2 . In other words, the driver tends to swing the shift control lever while pulling it up by a distance equal to a deviation between the direction d 1 ′ and the intended direction d 1 . If a distance the shift control lever  2  is pulled up due to the aforesaid lever operation exceeds a predetermined pull-up distance which regulates lever shifting between two gear positions, an unintended gear position (for instance, a parking gear position) is engaged irrespective of a driver&#39;s intention to engage a currently intended gear position (for instance, a drive range position). 
   Next, a pull-up operation of the shift control lever  2  will be considered with reference to a case where the gears are shifted from the parking position to any of the other gear positions. This gear shifting needs a lever operation in which the shift control lever  2  which is being located at the parking position is pulled up a predetermined distance in the direction d 2  before it is swung. In this pull-up operation, the shift control lever  2  can be shifted in the direction d 2 , but the lever is restricted from being shifted in the direction d 1  by the mechanism of this shift control device. Since the driver tends to pull up the shift control lever in a direction toward the rotational center P of his or her shoulder (move the shift control lever in the direction d 2 ′), the shift control lever  2  tends to be shifted toward the direction d 2 ′. In other words, the driver tends to pull up the shift control lever  2  while applying thereto a force in a direction deviating from the intended direction d 2  toward the direction d 1 ′. However, since the movement in the direction d 1 ′ is restricted, the shift control lever  2  is shifted in the direction d 2  which is different from the driver&#39;s intended direction d 2 ′. As a result of this, there may be a risk of the driver eventually feeling an unnatural shift lever operation feeling. 
   SUMMARY OF THE INVENTION 
   In view of the problem inherent in the prior art, it is an object of the present invention to provide a shift control device for a transmission mechanism for a motor vehicle which can prevent the occurrence of a gear shift which the driver does not intend to have. 
   It is another object of the present invention to improve the operability of the shift control device that will be so provided. 
   With a view to solving the aforesaid problem, a first aspect of the present invention provides a shift control device for a transmission mechanism for a motor vehicle in which gear shifting is performed by a shift control lever provided in the vicinity of a steering wheel for column shifting, comprising: 
   a guide member movable in a first direction by swing operating the shift control lever and in a second direction different from the first direction by pull-up operating the shift control lever; and a regulating member having a plurality of steps for regulating the movement of the guide member in said first direction, whereby the operating distance to pull up the shift control lever is regulated by heights of the plurality of steps, respectively; wherein the heights of said plurality of steps for regulating the operating distance to pull up the shift control lever at the time of gear shifting accompanied by a pull-up operation of the shift control lever are greater than a travelling distance of the guide member in the second direction when the shift control lever is caused to travel from a position before the gear shifting to a position thereafter with a distance between a position of the shift control lever before the gear shifting and a shoulder point of the driver at his or her own driving position being maintained substantially constant. 
   A second aspect of the present invention provides a shift control device for a transmission mechanism for a motor vehicle in which gear shifting is performed by a shift control lever provided in the vicinity of a steering wheel for column shifting, comprising: 
   a shift shaft movable in response to operation of the shift control lever; a guide member movable in a first direction by swing operating the shift control lever and in a second direction different from the first direction by pull-up operating the shift control lever; and a regulating member having a slidable portion for regulating a direction in which the shift control lever is pulled up through abutment with the guide member; wherein a first angle forming an acute angle by a travelling direction of the guide member in which the guide member travels while kept in abutment with the slidable member through the pull-up operation of the shift control lever and a reference line is smaller than a second angle forming an acute angle by an axial direction of the shift shaft and the reference line, and wherein; the reference line is a line connecting the position of the shift control lever and the shoulder point of the driver at his or her own driving position. 
   A third aspect of the present invention provides a shift control device for a transmission mechanism for a motor vehicle in which gear shifting is performed by a shift control lever provided in the vicinity of a steering wheel for column shifting, having a guide member movable in a first direction by swing operating the shift control lever and in a second direction different from the first direction by pull-up operating the shift control lever; and a regulating member having a slidable portion for regulating a direction in which the shift control lever is pulled up through abutment with the guide member; and wherein a travelling path of the guide member along which the guide member travels while kept in abutment with the slidable member through the pull-up operation of the shift control lever is substantially parallel with a reference line which connects the position of the shift control lever and the shoulder point of the driver at his or her own driving position. 
   A fourth aspect of the present invention provides a shift control device for a transmission mechanism for a motor vehicle in which gear shifting is performed by a shift control lever provided in the vicinity of a steering wheel for column shifting, having: a shift shaft movable in response to operation of the shift control lever; a guide member movable in a first direction by swing operating the shift control lever and in a second direction different from the first direction by pull-up operating the shift control lever; and a regulating member having a plurality of steps for regulating the movement of the guide member in the first direction, whereby the operating distance to pull up the shift control lever is regulated by heights of the plurality of steps, respectively and a slidable portion for regulating a direction in which the shift control lever is pulled up through abutment with the guide member; wherein the heights of the plurality of steps for regulating the operating distance to pull up the shift control lever at the time of gear shifting accompanied by a pull-up operation of the shift control lever are greater than a travelling distance of the guide member in the second direction when the shift control lever is caused to travel from a position before the gear shifting to a position thereafter with a distance between a position of the shift control lever before the gear shifting and a shoulder point of the driver at his or her own driving position being maintained substantially constant; and wherein a first angle forming an acute angle by a travelling direction of the guide member in which the guide member travels while kept in abutment with the slidable member through the pull-up operation of the shift control lever and a reference line which connects the position of the shift control lever and the shoulder point of the driver at his or her own driving position is smaller than a second angle forming an acute angle by an axial direction of the shift shaft and the reference line. 
   In the above constructions, it is desirable that the guide member is a guide pin having a substantially circular cross section and that the heights of the plurality of steps are greater than a sum of a travelling distance of the guide member in the second direction when the shift control lever is caused to travel from a position before the gear shifting to a position thereafter with a distance between a position of the shift control lever before the gear shifting and a shoulder point of the driver at his or her own driving position being maintained substantially constant and the radius of the guide pin. 
   In addition, the regulating member may be a guide plate formed on a concentric circle about a center of the shift shaft. 
   Furthermore, the guide member may be a detent pawl, and the regulating member may be a detention body. 
   A fifth aspect of the present invention provides a shift control device for a transmission mechanism for a motor vehicle in which gear shifting is performed by a shift control lever provided in the vicinity of a steering wheel for column shifting, comprising: 
   a steering shaft movable in response to operation of the steering wheel; a shift shaft rotatable when the shift control lever is operated in a first direction and movable in an axial direction when the shift control lever is operated in a second direction which is different from the first direction, wherein an axial direction of the shift shaft and an axial direction of the steering shaft are different from each other. 
   A sixth aspect of the present invention provides a shift control device for a transmission mechanism for a motor vehicle in which gear shifting is performed by a shift control lever provided in the vicinity of a steering wheel for column shifting, comprising: 
   a steering shaft movable in response to operation of the steering wheel; and a shift shaft rotatable when the shift control lever is operated in a first direction and movable in an axial direction when the shift control lever is operated in a second direction which is different from the first direction, wherein; a first angle forming an acute angle by an axial direction of the shift shaft and a horizontal line is smaller than a second angle forming an acute angle by an axial direction of the shift shaft and the horizontal line. 
   A seventh aspect of the present invention provides a shift control device for a transmission mechanism for a motor vehicle, comprising: 
   a steering wheel; a shift control lever provided in the vicinity of the steering wheel for column shifting; and a shift shaft rotatable when the shift control lever is operated in a first direction and movable in an axial direction when the shift control lever is operated in a second direction which is different from the first direction, wherein; a line connecting the shift control lever and a shoulder point of the driver at his or her own driving position is substantially parallel with the axial direction of said shift shaft. 
   A eighth aspect of the present invention provides a shift control device for a transmission mechanism for a motor vehicle, comprising: 
   a steering wheel; a shift shaft rotatable and movable in an axial direction thereof; and a shift control lever for column shifting provided in the vicinity of the steering wheel, kept in engagement with the shift shaft, and adapted to rotate the shift shaft when moved in a first direction and move the shift shaft in the axial direction when moved in a second direction which is different from the first direction; wherein a first angle forming an acute angle by the first direction of the shift control lever and a vertical line is smaller than a second line forming a smallest acute angle by a straight line on a plane of the steering wheel and the horizontal line. 
   A ninth aspect of the present invention provides a shift control device for a transmission mechanism for a motor vehicle, comprising: 
   a steering wheel; a steering shaft movable in response to operation of the steering wheel; a shift shaft rotatable and movable in an axial direction thereof; and a shift control lever for column shifting provided in the vicinity of the steering wheel, kept in engagement with the shift shaft, and adapted to rotate the shift shaft when moved in a first direction and move the shift shaft in the axial direction when moved in a second direction which is different from the first direction; wherein a first angle forming an acute angle by said second direction of the shift control lever and a horizontal line is smaller than a second angle forming an acute angle by the axial direction of the steering shaft and the horizontal line. 
   In a shift control device for a transmission mechanism for a motor vehicle as set forth in the above fifth to ninth aspects, there may be provided a guide member movable in a third direction by swing operating said shift control lever and in a fourth direction different from said third direction by pull-up operating said shift control lever and a regulating member having a plurality of steps for regulating the movement of the guide member in said third direction, whereby the operating distance to pull up the shift control lever is regulated by heights of the plurality of steps, respectively. In this case, the heights of the plurality of steps for regulating the operating distance to pull up the shift control lever at the time of gear shifting accompanied by a pull-up operation of the shift control lever are greater than a travelling distance of the guide member in the second direction when the shift control lever is caused to travel from a position before the gear shifting to a position thereafter with a distance between a position of the shift control lever before the gear shifting and a shoulder point of the driver at his or her own driving position being maintained substantially constant. 
   In a shift control device for a transmission mechanism for a motor vehicle as set forth in the above fifth to ninth aspects, there may be provided a guide member movable in a third direction by swing operating the shift control lever and in a fourth direction different from the third direction by pull-up operating said shift control lever; and a regulating member having a slidable portion for regulating a direction in which the shift control lever is pulled up through abutment with the guide member. In this case, a first angle forming an acute angle by a travelling direction of the guide member in which the guide member travels while kept in abutment with the slidable member through the pull-up operation of the shift control lever and a reference line which connects the position of the shift control lever and the shoulder point of the driver at his or her own driving position is smaller than a second angle forming an acute angle by an axial direction of the shift shaft and the reference line. 
   In a shift control device for a transmission mechanism for a motor vehicle as set forth in the above fifth to ninth aspects, there may be provided a guide member movable in a third direction by swing operating the shift control lever and in a fourth direction different from the third direction by pull-up operating the shift control lever, and a regulating member having a slidable portion for regulating a direction in which the shift control lever is pulled up through abutment with the guide member. In this case, a travelling path of the guide member along which the guide member travels while kept in abutment with the slidable member through the pull-up operation of the shift control lever is substantially parallel with a reference line which connects the position of the shift control lever and the shoulder point of the driver at his or her own driving position. 
   In a shift control device for a transmission mechanism for a motor vehicle as set forth in the fifth to ninth aspects, there may be provided a guide member movable in a third direction by swing operating the shift control lever and in a fourth direction different from the third direction by pull-up operating the shift control lever and a regulating member having a plurality of steps for regulating the movement of the guide member in the third direction, whereby the operating distance to pull up the shift control lever is regulated by heights of the plurality of steps, respectively and a slidable portion for regulating a direction in which the shift control lever is pulled up through abutment with the guide member. In this case, the heights of the plurality of steps for regulating the operating distance to pull up the shift control lever at the time of gear shifting accompanied by a pull-up operation of the shift control lever are greater than a travelling distance of the guide member in the second direction when the shift control lever is caused to travel from a position before the gear shifting to a position thereafter with a distance between a position of the shift control lever before the gear shifting and a shoulder point of the driver at his or her own driving position being maintained substantially constant and a first angle forming an acute angle by a travelling direction of the guide member in which the guide member travels while kept in abutment with the slidable member through the pull-up operation of the shift control lever and a reference line which connects the position of thed shift control lever and the shoulder point of the driver at his or her own driving position is smaller than a second angle forming an acute angle by an axial direction of the shift shaft and said reference line. 
   The present disclosure relates to subject matter contained in Japanese Patent Application No. Hei. 10-301605, filed on Oct. 7, 1998, and which is expressly incorporated herein by reference in its entirety. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic plan view showing an example of a steering device and a transmission mechanism shift control device; 
       FIG. 2  is a side view showing a main part of the transmission mechanism shift control device shown in  FIG. 1 ; 
       FIG. 3  is a sectional view taken along the line C-C′ of the transmission mechanism shift control device shown in  FIG. 1 ; 
       FIG. 4  is an unfolded view of a main part of a guide plate; 
       FIG. 5  is a schematic diagram for explaining a first embodiment; 
       FIG. 6  is a schematic diagram for explaining a second embodiment; 
       FIG. 7  is a schematic diagram for explaining a third embodiment; 
       FIG. 8  is a schematic diagram for explaining a fourth embodiment; 
       FIG. 9  is a schematic diagram showing a construction of another transmission mechanism shift control device; 
       FIG. 10  is a diagram showing a main part of the transmission mechanism shift control device shown in  FIG. 9 ; 
       FIG. 11  is a schematic diagram for explaining a fifth embodiment; 
       FIG. 12  is a schematic diagram for explaining a sixth embodiment; 
       FIG. 13  is a schematic diagram for explaining a seventh embodiment; and 
       FIG. 14  is a diagram explaining a conventional column-type transmission shift control device. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  is a schematic plan view showing a steering device and an example of a shift control device for a transmission mechanism, and  FIG. 2  is a side view of a main part of the shift control device for a transmission mechanism shown in FIG.  1 . In the figures, reference numerals  11 ,  12  and  13  denote a steering support beam, a toe board and an instrument panel, respectively. A steering device  14  is provided and supported on the steering support beam  11  and the toe board  12 . A transmission shift control device  15  is disposed at a position close to the steering device  14  and mounted on the steering support beam  11 . 
   In the steering device  14 , a steering shaft  16  penetrates the toe board  12  to be connected at one end thereof to a steering gear box not shown and has a steering wheel  1  mounted on the other end thereof. The steering shaft  16  is graspingly held by a steering column mounted on the steering support beam  11  and the toe board  12 , and rotates in accordance with a distance the steering wheel  1  is operated. Mounted on the steering column  18  are various controls such as a direction indicator control lever  19 , a windshield wiper control lever  30 , and an ignition key  21 . 
   A shift shaft  22  is disposed in the transmission shift control device  15  in such a manner that an axis S 2  thereof becomes substantially parallel with an axis S 1  of the steering shaft  16 . The shift shaft  22  comprises a rotatable tubular outer shaft  23  and a post-like inner shaft  24  which is fittingly inserted into the outer shaft  23  in such a manner as to move in an axial direction and rotate therein. Insertion holes are formed in one side of the outer shaft  23  and inner shaft  24 , respectively, and a guide pin  25  having a substantially circular cross-section is inserted from the insertion hole of the outer shaft  23 , penetrates the insertion hole of the inner shaft  24  and reaches the outer shaft  23 . In addition, a spring  27  is provided on the one side of the inner shaft  24 , so that the inner shaft  24  is biassed toward the other side thereof at all times. On the other hand, a projection  28  is provided on the other side of the outer shaft  23  for supporting a shift control lever  2  (so called as a selector lever) for column shifting and an insertion hole is also formed in the same side of the outer shaft  23  for a distal end portion of the shift control lever  2  to be inserted thereinto. The inner shaft  24  is brought into engagement with the distal end portion of the shift control lever  2  for column shifting at one end on the other side thereof. The shift control lever  2  protruding into a passenger compartment through the instrument panel  13  is supported on a rotating shaft  26  provided on the projection  28  in such a manner as to rotate thereon, whereby an operation of the shift control lever  2  is converted into a movement of the shift shaft  22 . 
   When the shift control lever  2  is shifted about the axis S 2  (the position of the shift control lever  2  is shifted to a position shown in FIG.  2 ), the outer shaft  23  rotates about the axis S 2 , and the inner shaft  24  also rotates via the guide pin  25 . On the contrary, when the shift control lever  2  is pulled up (the position of the shift control lever  2  is shifted to a position shown in FIG.  1 ), the shift control lever  2  swings about the rotating shaft  26 . This causes the distal end portion of the shift control lever  2  to push the inner shaft  24  along the axis S 2  against the spring force applied by the spring  27 . When the shift control lever  2  is released from the pulled-up state, the inner shaft  24  operates so as to be restored toward the distal end portion side of the shift control lever  2  by virtue of the spring or biassing force of the spring  27 . 
   A detent plate  31  operates interlockingly with the outer shaft  23 , and a distal end portion thereof engages one end of a shift arm  32 . The L-shaped shift arm  32  is mounted on a shift arm support shaft in such a manner as to rotate about the same shaft, and formed on the other end thereof is a support portion of a select cable  33 . When the outer shaft  23  rotates, the distal end portion of the detent plate  31  swings, and the shift arm  32  engaged with the distal end portion of the detent plate  31  swings in turn. A displacement of the shift arm  32  like this is then transmitted to a change-speed control device not shown via the select cable  33 , whereby the transmission control-device performs a desired gear shift. 
   A guide plate  29  is provided in the vicinity of the guide pin  25  for regulating a shiftable range for the shift control lever  2  in conjunction with the guide pin  25 . The guide plate  29  is a flat plate having a predetermined thickness and formed into an arc-like or C-shaped configuration.  FIG. 3  is a sectional view taken along the line C-C′ of the transmission mechanism shift control device shown in FIG.  1 . As is clear from this view, the guide plate  29  is attached with a bolt or the like to an outer circumference of a holder portion  30  on a concentric circle about the center of the shift shaft  22 . In addition,  FIG. 4  is a plan view of an unfolded main part of the guide plate. 
   This guide plate  29  has an opening  34  and the configuration of the opening  34  regulates a shiftable range for the guide pin  25  (in other words, a shiftable range for the shift control lever  2 ). In  FIG. 4 , reference character P denotes a position the guide pin  25  at a parking position (hereinafter, referred to as P position). In addition, reference characters R, N, D and S denote positions of the guide pin  25  at a reverse position (R position), a neutral position (N position), a drive position (D position), and a sport position (S position), respectively. Steps are provided between the shift positions except for between the D-N positions. These steps regulate operating distances that the shift control lever  2  is pulled up for the respective gear shifts. Here, assume that the gears are shifted from N position to D position. In this case, when the shift control lever  2  is shifted toward a lower side thereof, the guide pin  25  swings the shift shaft  22  about the axis S 2 . This means that in  FIG. 3  the guide in  25  is shifted clockwise about the axis S 2  of the shift shaft  22 , and that in  FIG. 4 , the guide pin  25  is shifted rightward. When the guide pin  25  is brought into abutment with the step between D-S positions, the guide pin  25  can move rightward no farther than the step, whereby the shift of the shift control lever  2  is regulated. 
   Next, a gear shift from N to R positions will be considered in which the shift control lever  2  needs to be pulled up. If the shift control lever  2  is tried to be shifted to an upper side without being pulled up or if it is not sufficiently pulled up, the guide pin  25  is restricted from being shifted leftward by the step between N-R positions, as shown in FIG.  4 . However, the guide pin  25  positioned at R position starts to move toward the upper side when the shift control lever  2  is sufficiently pulled up, as shown in  FIG. 4 , and when the lever is pulled up higher than the height of the step between N-R positions, the guide pin  25  is permitted to be shifted leftward. In other words, when the shift control lever  2  is swung upwardly after it is pulled up sufficiently, the guide pin  25  is released from the restricted movement by the step between N-R positions as shown in  FIG. 4 , and as a result of this, as shown in  FIG. 3 , the guide pin  25  rotates counterclockwise about the axis S 2  from N to R positions. When it comes to abutment with the step between R-P positions as shown in  FIG. 4 , the guide pin  25  is not permitted to move leftward any farther, and therefore the shift control lever  2  is restricted from swinging. When shifted from N to R positions, since there is a need to pass over no step, the shift control lever  2  does not have to be pulled up. When shifted from N to R positions, from R to P positions, and from P to R positions, the guide pin  25  needs to be pulled up higher than the height of the steps between the respective positions, as so it does when shifted from N to R positions. 
   (First Embodiment) 
     FIG. 5  is a schematic diagram for explanation of a first embodiment. In this diagram, it should be noted that the shift control lever  2  extends toward the viewer of the diagram, that the guide pin  25  extends toward the back side of the diagram and that the guide plate  29  is provided on the back side of the diagram. When shifted from D position to N position, the shift control lever starts to move from D position toward the upper side. When that happens, the driver tends to operate the shift control lever  2  on a concentric circle about the rotational center of his or her shoulder. It is a most natural movement to the driver to operate the shift control lever  2  by virtue of the rotation of the shoulder without bending the arm. Here, the rotational center of the shoulder of the driver of a “standard build” at his or her driving position is defined as a “shoulder point” P. In the case of the Japanese, a dummy (JM50) may be considered as the “standard build.” Of course, the builds and heights of people differ from country to country, the “shoulder point” may be set individually with reference to the standard build of the people of a country to which motor vehicles are exported. Thus, the shift control lever  2  tends to be operated on a concentric circle about the shoulder point P, in other words, with a distance between the shoulder point P and the position of the shift control lever  2  being maintained constant. 
   As shown in  FIG. 5 , in a case where directions of the axis S 1  of the steering shaft  16  and the axis S 2  of the shift shaft  22  coincide with each other, from the aforesaid driver&#39;s tendency to operate the shift control lever, the shift lever  2  located at D position is shifted with the distance from the shoulder point P being maintained constant (this shift operation being indicated by a vector d 1 ′). Since the vector D 1 ′ deviates from an originally intended vector d 1 , in other words, a swinging direction of the shift control lever  2  without pulling it up, a pull-up operation is added which the driver never intends to do. A shift distance associated with this pull-up operation is indicated by reference character/numeral A 1 . The shift shaft  22  rotates while being shifted from the shift control lever  2  side toward the guide plate  29  due to the shift of the shift control lever  2  toward the upper side (vector d 1 ′) accompanying the pull-up operation. The guide pin  25  is shifted from D position in the guide plate  29  as shown by a vector e 1  when the shift control lever  2  is shifted axially. An axial component of this vector e 1  (i.e., an axial shift distance of the guide pin  25  corresponding to the shift distance A 1  of the shift control lever  2 ) is denoted by reference character/numeral a 1 . 
   In a case where the axial shift distance a 1  of the guide pin  25  exceeds the height of the step between N-R positions, the guide pin  25  is engaged in R position without abutment with the step. To prevent the generation of a malfunction like this, the height of the step between N-R positions may be set in consideration of the driver&#39;s unintentional pull-up distance A 1 . In other words, the height of the step may be set higher than the shift distance in the axial direction S 2  of the guide pin  25  which is shifted by the shift distance A 1  of the shift control lever  2 . In  FIG. 5  a shaded step portion by diagonal lines is a portion additionally provided on the existing step portion to have a higher height from the aforesaid reason. In addition, a gear shift from D to R positions accompanied by a pull-up operation of the shift operation lever  2  can be completed by pulling up the shift control lever  2  a shift distance greater than the height of the step between N and R positions. 
   When the guide pin  25  having a substantially circular cross-section is used, it is desirable to set the height of the step between N-R positions greater than a sum of the shift distance a 1  and the radius of the circular cross-section of the guide pin  25  (similar in the following embodiments, too). An erroneous gear shift can be prevented from occurring further effectively by increasing the height of the step by a height corresponding to the radius of the circular cross-section of the guide pin  25 . Namely, if the height of the step is higher than the shift distance a 1  but lower than the sum of the shift distance a 1  and the radius of the guide pin, the center of the cross-section of the guide pin  25  becomes higher than the height of the step. As a result of this, there may be a risk that the guide pin sliding over a top portion G of the step with which it abuts to be shifted in R position. If the step is formed further higher by equal to or more than the radius of the guide pin  25 , since there is no chance for the center of the cross-section of the guide pin  25  to become higher than the height of the step, the gear shift to R position can thus be prevented. 
   As is clear from the above description, in this embodiment, the steps in the guide plate  29  are set higher by taking into consideration the driver&#39;s operation tendency in operating the shift control lever  2  vertically. In other words, the step between N-R positions is formed higher than the shift distance of the guide pin  25  corresponding to the pull-up distance when the shift control lever  2  is operated vertically with the distance from the shoulder point P being maintained constant. This can effectively prevent the occurrence of an erroneous gear shift into R positions as a result of an unintentional pull-up operation of the shift control lever  2  when shifted from D position to N position. 
   (Second Embodiment) 
     FIG. 6  is a schematic diagram for explanation of a second embodiment. From the same reason as that explained in the description of the first embodiment, an erroneous gear shift into R position may occurr when shifted from S position to N position. A vector d 2  in  FIG. 6  denotes a direction and a shift distance that are originally intended when the shift control lever  2  is shifted from S position toward P position. On the other hand, a vector d 2 ′ denotes a direction and a shift distance when the shift control lever  2  is rotated with the distance from the shoulder point being maintained the same. Denoted by A 2  is a shift distance, i.e., a pull-up distance generated in the direction of the axis S 2  of the shift shaft  22  by virtue of a difference between those vectors d 2 , d 2 ′. When the shift control lever  2  is operated as indicated by the vector d 2 ′, the guide pin  25  is shifted within the guide plate  29  as indicated by a vector e 2 . 
   Reference character/numeral a 2  is a shift distance in the direction of the axis S 2  when the guide pin  25  is shifted as indicated by the vector e 2 . When the height of the step between S-R positions (i.e., a difference in height between the step between N-R positions and the step between D-S positions) is equal to or lower than a shift distance a 2 , the guide pin  25  is shifted into R position. To cope with this, in this embodiment, the step between D-S positions is formed lower and the step between N-R positions is formed higher, or the step of the former is formed lower, and the step for the latter is formed higher, whereby it is effective to set the step between S-R positions higher than the shift distance a 2 . This can effectively prevent the occurrence of an erroneous gear shift into R position when shifted from S position to N position. In addition, when tried to be shifted from S position to R position accompanied by a pull-up operation of the shift control lever  2 , the shift control lever  2  is pulled up an operation distance greater than the height of the step. 
   (Third Embodiment) 
   The object of the first and second embodiments described above is to prevent an erroneous gear shift, while an object of third and fourth embodiments that will be described below is to improve the operability of the shift control lever  2 .  FIG. 7  is a schematic diagram for explaining the third embodiment. When shifted from P position to R position, the shift control lever  2  is operated to be shifted to a lower side after it is pulled up. To try to explain this through the movement of the guide pin  25 , after it is shifted a shift distance greater than the height of the step between P-R positions in the direction S 2  of the shift shaft  22 , the guide pin  25  is shifted in a direction normal to the direction S 2 . 
   When he or she pulls it up, the driver tends to pull up the shift control lever  2  in a direction d 3 , in other words, in a direction from the shift control lever  2  toward the shoulder point P. Since the movement of the guide pin  25  is restricted by the configuration of the guide plate  29 , however, the shift control lever  2  is permitted to be shifted only in the direction S 2 . Therefore, the shift control lever  2  has to be shifted in the direction of the axis S 2  of the shift shaft. When this direction is looked at from the driver side, the shift control lever is pulled up in a direction slightly upwardly of the direction d 3  which makes the driver feel the most natural pull-up feeling, and therefore the permitted pull-up direction may make the driver feel an unnatural lever operation feeling. In addition, if the edge portion of the guide plate  29  for regulating the movement of the guide pin  25  when it is pulled up is not formed smoothly and has some irregularities therealong, vibrations generated by such unsmoothness and irregularities may be transmitted to the shift control lever  2 , thereby making the driver feel an uncomfortable feeling. 
   To cope with this, as shown in  FIG. 7 , a portion of the step between P-R positions which is shaded with diagonal lines is cut. Here, a direction of an edge portion of a sliding portion  70  which is newly formed by cutting the diagonally lined portion, or a direction of an edge portion along which the guide pin  25  is caused to slide while kept in abutment therewith is denoted by reference character/numeral de 4 . Then, an acute angle is referred to as angle θ 1  which is formed by the direction d 4  of the edge portion (sliding direction) and a straight line L parallel with a straight line connecting the shift control lever  2  and the shoulder point P. On the other hand, an acute angle is referred to as angle θ 2  which is formed by the axis S 2  of the shift shaft  22  and the straight line L. In this case, the step is configured such that the angle θ 1  with respect to the direction of the edge portion is smaller than the angle θ 2  with respect to the axis S 2  of the shift shaft. From the viewpoint of the shift feeling, it is preferable that the angle θ 1  approximates as close to zero as possible, in other words, the sliding direction d 4  and the straight line L are substantially parallel with each other. 
   By forming the step between P-R positions, if the driver tries to pull up the shift control lever in the direction d 3 , since the guide pin  25  is shifted as shown by the vector d 4 , the shift control lever  2  is shifted toward the direction d 3 . This prevents the driver from being caused to feel an unnaturally unsmooth feeling, thereby making it possible to improve further the lever shift feeling. In addition, since there is no chance for the guide pin  25  to be brought into a strong abutment with the sliding portion  70 , vibrations arising from the irregularities along the sliding portion can be prevented from being transmitted to the driver. 
   (Fourth Embodiment) 
     FIG. 8  is a schematic diagram for explaining a fourth embodiment. From the same reason as that explained in the third embodiment, even when shifting gears from D to S positions, there is probability that the driver will be feel an unnatural shift feeling. To cope with this, as shown in  FIG. 8 , a part of the step between D-S positions in the guide plate  29  is cut diagonally. Here, indicated by reference character/numeral d 5  is a direction of an edge portion of a sliding portion  80  where the guide pin  25  is shifted while kept in abutment therewith or a direction in which the guide pin  25  is shifted while kept in abutment the sliding portion  80 . Then, an acute angle is referred to as angle θ 3  which is formed by the direction d 4  of the edge portion (sliding direction) and a straight line L parallel with a straight line connecting the shift control lever  2  and the shoulder point P. On the other hand, an acute angle is referred to as angle θ 4  which is formed by the axis S 2  of the shift shaft  22  and the straight line L. In this case, the step is configured such that the angle θ 3  with respect to the direction of the edge portion is smaller than the angle θ 4  with respect to the axis S 2  of the shift shaft. As with the third embodiment, from the viewpoint of the shift feeling, it is preferable that the angle θ 1  approximates as close to zero as possible. 
   In addition, preferably, the above first to fourth embodiments are combined with one another, by which the shift feeling in the respective gear shifts can be improved and the occurrence of erroneous gear shifts can further be prevented. 
   Thus, in the above first to fourth embodiments, the shift control device for a transmission mechanism has been described in which the shift of the shift control lever is regulated by means of the guide pin and the guide plate. The present invention, however, is not limited to a shift control device constructed as described in those embodiments and it may be applied to a shift control device for a transmission mechanism which is constructed in another way. As examples of such a device, embodiments will be described below in which the present invention is applied to the transmission mechanism shift control devices shown in  FIGS. 9 and 10 . 
   (Fifth Embodiment) 
   A shift control lever mounting shaft  90  is provided in the vicinity of the steering shaft  16 , and the shift control lever  2  is mounted on this mounting shaft  90 . A detent pawl  91 , which is a flat plate-like guide member, is integrally provided on the shift control lever. This detent pawl  91  regulates the shift of the shift control lever  2  in conjunction with a detention body  92 . In other words, the detent pawl  91  mounted on the shift control lever  2  plays a role of the guide pin in the transmission mechanism shift control device shown in  FIG. 1 , and the detention body  92  as a role of the guide plate in the same device. 
     FIG. 11  is a schematic diagram explaining the fifth embodiment. An object of this embodiment is to prevent an erroneous gear shift when gears are shifted from D position (or 2 nd  position) to R position, and the embodiment can be a modification of the first and second embodiments. The shift control lever is swung with the distance from the shoulder point being maintained equal or constant. This allows the shift control lever  2  to be pulled up and the detent pawl  91  to be shifted as indicated by a vector e 4 , a shift distance a 3  being generated in a direction of the height of the step of the detention body  92 . To cope with this, the height of the step between N-R positions is set greater than the shift distance a 3  of the detent pawl  91 . The detent pawl  91  is a flat plate, its area engaging the step of the detention body  92  is wide, and the pawl does not have any curved surface, and therefore no compensating means, such as those described in the first and second embodiments, needs to be provided (the height of the step is increased by a distance equal to the radius of the guide pin). 
   In addition, in order to prevent an erroneous gear shift when shifted from 2 nd  position to R position, the step between 2-R positions may be set in the same manner as done in the second embodiment (the difference in height between the step between N-R positions and the step between D-R positions). 
   (Sixth Embodiment) 
     FIG. 12  is a schematic diagram for explaining a sixth embodiment. This embodiment is needed when the gears are shifted from P position to R position. An object of this embodiment is to improve the shift feeling when the shift control lever  2  is pulled up, and the embodiment may be regarded as a modification of the third and fourth embodiments. The driver tries to operate the shift control lever toward the shoulder point. This causes the detent pawl to be caught on a sliding portion of the step between P-R positions, and a direction in which the shift control lever can be pulled up is different from a direction which makes the driver feel no feeling of physical disorder. Then, to cope with this, the detent pawl  91  is configured such that it is partially cut (a diagonally lined portion corresponds to a cut-away portion. To be specific, the portion is diagonally cut in a linear, curved or parabolic fashion. This can provide the same effectiveness as those provided by the third and fourth embodiments. The specific conditions of those configurations are substantially the same as those described in the third and fourth embodiments, and therefore, a description thereof will be omitted here. In addition, as with the third and fourth embodiments, in this embodiment, too, the step between P-R positions, D-2 nd  positions, or 2 nd -L positions on the detention body  92  side may be cut. Alternatively, instead of the detent pawl side, the detention body side may be cut as described above, or both the detent pawl and detention body sides may be cut. 
   (Seventh Embodiment) 
     FIG. 13  is a schematic diagram for explaining a seventh embodiment of a transmission mechanism shift control device. The transmission mechanism shift control device according to this embodiment is basically identical to the previously described ones in that the components shown in  FIGS. 1 and 2  are used therein but is different from those in the mounting of the transmission mechanism shift control device  15  relative to the steering shaft  14 . In other words, the shift shaft  22  is mounted on the transmission mechanism shift control device  15  such that the axis S 2  of the shift shaft is oriented in a direction different from that of the axis S 1  of the steering shaft  16 . This is effected by setting the shift control device such that an angle θ 1  forming an acute angle by the axial direction S 2  of the shift shaft  22  and a horizontal line is smaller than an angle θ 2  forming an acute angle by the axial direction S 1  of the steering shaft  16  and the horizontal line. In other words, it is constructed such that an angle θ 3  forming an acute angle by a swinging direction d 3  of the shift control lever  2  and a vertical line V is smaller than an angle θ 4  forming a smallest acute angle by a straight line on the plane of the steering wheel  1  and the vertical line V. Thus, if the transmission mechanism shift control device  15  is disposed such that a straight line L connecting the shift control lever  2  with the shoulder point P and the axis S 2  of the shift shaft  22  are substantially parallel with each other, the shift control lever can be operated with the distance between the shift control lever  2  and the shoulder point P being maintained substantially constant. As a result of this, from the reason described heretofore, erroneous gear shifting can be prevented. In addition, even when the shift control lever  2  is pulled up, since the pull-up direction coincides with the axis S 2  of the shift shaft  22 , the driver is prevented from feeling a feeling of physical disorder or discomfort, whereby the shift feeling can further be improved. 
   The seventh embodiment can be combined with the first to sixth embodiments. Namely, the axial direction S 2  of the shift shaft  22  is offset from the axial direction S 1  of the steering shaft  16  to some extent, and the steps of the regulating member for the guide plate or the like may be configured as described in the above embodiments. 
   For instance, as is described in the first and second embodiments, the height of the step may be made greater than the shift distance resulting when the shift control lever is shifted to be pulled up with the distance between the lever and the shoulder point being maintained substantially constant before or after gear shifting. In addition, as described in the third and fourth embodiments, in a case where the guide pin is shifted along the sliding portion while kept in abutment therewith as a result of the shift control lever being operated so as to be pulled up, it may be constructed such that the angle forming an acute angle by the shift direction of the guide pin and the reference line is smaller than the angle forming an acute angle by the axial direction of the shift shaft and the reference line. Here, the reference line is a line connecting the position of the shift control lever with the shoulder point of the driver at his or her driving position. Thus, preferably, the shift path of the guide member in which the guide member is shifted along the sliding portion while kept in abutment therewith when the shift control lever is operated to be pulled up is substantially parallel with the reference line. Furthermore, these features may be combined with each other. 
   Even if the axis of the shift shaft cannot be parallel with the line connecting the shift control lever and the shoulder point due to a problem with the disposition of the transmission mechanism shift control device, the shift feeling can further be improved and the occurrence of erroneous gear shifting can further be prevented by devising the configuration of the guide plate. 
   Thus, according to the present invention, even when the shift control lever is operated to be swung in a direction which makes the driver feel no feeling of physical disorder, an accurate gear shift can be effected with occurrence of no erroneous gear shift. In addition, since the shift control lever can be pulled up in a direction which makes the drive feel naturally, the shift feeling can further be improved. 
   While there has been described in connection with the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is aimed, therefore, to cover in the appended claim all such changes and modifications as fall within the true spirit and scope of the invention.