Column type change lever mechanism for automatic transmission in automotive vehicle

A column type change lever mechanism mounted on a tiltable steering shaft assembly having an upper steering column arranged to be tiltable upwardly or downwardly at a tilt center axis. The column type change lever mechanism is composed of a shift arm rotatably mounted on the upper steering column, a manual change lever connected to the shift arm to be operated for rotating the shift arm, a bell crank mounted on the upper steering column in such a manner as to be rotatable about an axis perpendicular to the tilt center axis and a central axis of the upper steering column and having a first arm pivoted to the shift arm and a second arm pivotally connected to one end of a forwardly extending push-pull cable the other end of which is operatively connected to an automatic transmission of an automotive vehicle.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a column type change lever mechanism 
mounted on a tiltable steering shaft assembly for selecting the operation 
mode of an automatic transmission in an automotive vehicle. 
2. Description of the Prior Art 
In Japanese Patent Laid-open Publication No. 62-105773, there has been 
proposed a column type change lever mechanism which includes a tiltable 
column change rod assembled in parallel with a tiltable steering shaft 
assembly. The column change rod is composed of an upper rod portion 
tiltably connected to a lower rod portion by means of a universal joint, 
while the steering shaft assembly is composed of an upper steering shaft 
tiltably connected to a lower steering shaft by means of a universal joint 
and rotatably supported within an upper column tube. The upper portion of 
the column change rod is mounted on a side portion of the upper column 
tube of the steering shaft assembly by means of a support bracket and is 
provided thereon with a manual change lever. In the column type change 
lever mechanism, the operation grip of the manual change lever is spaced 
from the central axis of the upper column tube in a distance between the 
upper portion of the column change rod and the upper column tube, and the 
component parts such as the column change rod, the manual change lever and 
the support bracket are arranged in a limited space at the side portion of 
the upper column tube. With such an arrangement of the column type change 
lever mechanism as described above, it is difficult to provide the manual 
change lever in an optimum length suitable for operation, and it is also 
difficult to assemble the component parts of the change lever mechanism 
with tiltable steering shaft assembly in the limited space. In the case 
that a collision energy absorbing mechanism is assembled with the steering 
shaft assembly, it is required to further assemble a collision energy 
absorbing mechanism with the column change rod, resulting in a complicated 
construction and an increase of manufacturing cost. 
SUMMARY OF THE INVENTION 
It is, therefore, a primary object of the present invention to provide an 
improved column type change lever mechanism the component parts of which 
can be mounted on a tiltable steering shaft assembly in a simple 
construction without causing any problems described above. 
According to the present invention, the object is accomplished by providing 
a column type change lever mechanism mounted on a tiltable steering shaft 
assembly having an upper steering column arranged to be tiltable upwardly 
or downwardly at a tilt center axis, which comprises a shift arm rotatably 
mounted on the upper steering column, a manual change lever connected to 
the shift arm to be operated for rotating the shift arm, a bell crank 
mounted on the upper steering column in such a manner as to be rotatable 
about an axis perpendicular to the tilt center axis and a central axis of 
the upper steering column and having a first arm pivoted to the shift arm 
and a second arm pivotally connected to one end of a forwardly extending 
push-pull cable the other end of which is operatively connected to an 
automatic transmission of an automotive vehicle.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
In FIGS. 1 and 2 of the drawings, there is illustrated a tiltable steering 
column assembly provided with a column type change lever mechanism 
according to the present invention. The tiltable steering column assembly 
includes an upper steering column 14 arranged to be tiltable upwardly or 
downwardly in a condition where a lock mechanism 12 has been released by 
operation of a manual tilt lever 11. The column type change lever 
mechanism includes a shift arm 15, a manual change lever 16 and a 
bell-crank 17. As shown in FIG. 3, an upper steering shaft 21a is 
rotatably mounted within the upper steering column 14 and provided thereon 
with a steering wheel 13 for rotation therewith. The upper steering shaft 
21a is provided at its tilt center with a universal joint (not shown) for 
connection with the upper end of a lower steering shaft 21b. The upper 
steering column 14 is connected at its lower end to the upper end of a 
lower steering column 22 mounted on a vehicle body structure (not shown) 
to be rotatable about a tilt center axis X and is provided thereon with a 
combination switch assembly 23. 
As shown in FIG. 3, the shift arm 15 of the column type change lever 
mechanism has an annular body portion 15a integrally provided with a 
detent plate 15a.sub.1, an output arm portion 15b formed with a ball joint 
15b.sub.1 for connection with a first arm 17a of the bell crank 17, and an 
input arm portion 15c formed with a U-letter shaped joint portion 
15c.sub.1 on which the manual change lever 16 is mounted at its base end 
portion 16a by means of a bolt 23 and a nut 24 to be rotatable about the 
bolt 23. The annular body portion 15a of shift arm 15 is rotatably 
assembled with a tubular portion 26a of the support member 26. (see FIGS. 
5 and 6) As shown in FIGS. 1 and 2, the support member 26 is secured to 
the upper steering column 14 in such a manner that the tubular portion 26a 
of support member 26 is coaxially coupled with the upper steering column 
14. As shown in FIG. 3, a ball 28 is received by a tubular holder 27 
secured to the support member 26 and is loaded by a compression spring 29 
for resilient engagement with the detent plate 15a.sub.1. In shifting 
operation of the manual change lever 16, the spring loaded ball 29 
cooperates with the detent plate 15a.sub.1 to afford a selection feel to 
the operator and to retain the change lever 16 at a selected position. 
As shown in FIGS. 3, 4(a) and 4(b, the manual change lever 16 is integrally 
provided at its base end portion 16a with a lock arm 16a.sub.1 and a 
retainer pin 16a.sub.2 and has an arm portion 16b secured to its base end 
portion 16a and an operation grip 16c secured to the outer end of arm 
portion 16b. As shown in FIG. 2, a tension coil spring 31 is engaged at 
its one end with the retainer pin 16a.sub.2 of change lever 16 and at its 
other end with the input arm portion 15c of shift arm 15 to bias the lock 
arm 16a.sub.1 of change lever 16 toward recessed surfaces 32a of a shift 
position plate 32 secured to the support member 26 for resilient 
engagement therewith. (see FIG. 5) As shown in FIG. 5, the recessed 
surfaces 32a of shift position plate 32 are formed to provide a parking 
position P, a reverse position R, a neutral position N, a drive position 
D, a second position 2 and a low range position L. When shifted from the 
neutral position P to the reverse position R or the parking position P or 
shifted from the drive position D to the second position 2 or the low 
range position L, the manual change lever 16 is operated against the load 
of spring 31 to be retained at a selected position. 
The bell crank 17 is pivotally connected at its first arm 17a to the output 
arm portion 15b of shift arm 15 through the ball joint 15b.sub.1 and has a 
second arm 17b pivotally connected to the rear end of a forwardly 
extending push-pull cable 18 through a ball joint 33 at a position located 
on the tilt center axis X. The bell crank 17 is rotatably mounted on a 
support pin 34 which is secured to the support member 26 and arranged 
along a vertical axis Z perpendicular to the tilt center axis X and the 
central axis Y of upper steering column 14. A retainer clip 35 is fixed to 
the support pin 34 to retain the bell crank 17 in place. In such an 
arrangement as described above, the bell crank 17 acts to transmit 
rotation of the shift arm 15 to the push-pull cable 18 for selecting the 
operation mode of an automatic transmission of the vehicle. 
Assuming that the manual change lever 16 is operated to rotate the shift 
arm 15 about the central axis Y of upper steering column 14 in a desired 
amount, the bell crank 17 is rotated about the vertical axis Z to move the 
push-pull cable 18 in a fore-and-aft direction for selecting the operation 
mode of the automatic transmission. When the upper steering column 14 is 
tilted with the steering wheel 13 upwardly or downwardly, the manual 
change lever 16, shift arm 15 and bell crank 17 are moved with the upper 
steering column 14. In this instance, the bell crank 17 is rotated about 
the tilt center axis X so that the push-pull cable 18 is remained in place 
without any movement. 
Since in the column type change lever mechanism the manual change lever 16 
is connected to the shift arm 15 rotatably mounted on the upper steering 
column 14, the manual change lever 16 can be provided in an optimum length 
suitable for operation without any problem. The component parts such as 
the shift arm 15, manual change lever 16, bell crank 17 and push-pull 
cable 18 can be assembled with the tiltable steering shaft assembly 
without any problem for mounting space thereof. Since the push-pull cable 
18 is arranged to be flexible at its intermediate portion, a collision 
energy absorbing mechansim can be assembled with the tiltable steering 
shaft assembly in a simple construction without providing any other energy 
absorbing mechanism on the column type change lever mechanism.