FIELD OF INVENTION
This invention relates to a gear shift lever assembly and a method
of assembly thereof and a lever rod. This invention has provision of
detachable lever rod.
BACKGROUND/PRIOR ART
Gear shift lever is an integral part of gear shift system which is
attached to gear shift lever assembly (GSLA). The purpose of said
lever is to act as interface between driver and gear box which
enables driver to shift the gears. It also contributes towards the
overall shift efforts requirements. As it is known gear shifting
efforts is inversely proportional to lever ratio (which is defined as
follows):
Lever Ratio = Li
L2
Li: Distance between centre of pivot ball to tip of lever rod (Knob
centre).
L2: Centre to centre distance between pivot ball and shift pin of
lever assembly.
Currently existing gear shift lever assembly is illustrated in fig. 1
indicating the following:-
Socket Liner-1
Knob-3
Noise Damper-5
Shift Pin-7
Spring (Anti Noise)-9
Fixation Shaft-11
Bush (4 places)-13
Lugs on socket-L
Lever Rod-2
Axle Lever Selection-4
Rivot Ball-6
Aronlock Washer-8
Shifter Box-10
Bell Crank-12
Silent Block (4 places)-14
In the current system the gear lever constitutes a single body with
pivot ball over molded to it which in turn is assembled to the GSLA
housing. There is a socket liner between the pivot ball and
housing. Thus, in the existing system the lever rod is assembled to
the GSLA with pivot ball as the pivot point on the housing Ss lever
interface about which the lever moves as per the desired gear
position.
The socket (1) is having a plurality of lugs (L) which are locked in
the corresponding holes (Pockets) (H) of housing (2) through
pressfit, which is best seen in the fig. lA.
Assembly procedure of the above will be mentioned hereinbelow:
- Welding of lever rod with axle lever selection (to select the
gear).
- Over molding of Pivot ball on the joint of axle lever selection
and lever rod.
- Riveting shift Pin at the end of lever sub assembly.
- Insertion of the subassembly thus obtained into Socket
- Snap fitting of the above subassembly on to the housing, so
that lugs of socket can be accommodated in the pockets of
housing, wherein the socket is positioned around the ball to
secure its position and to reduce rotational friction and
support radial and axial loads.
Here the lever and socket are assembled as single unit to the
housing.
The above discussed prior art involves the following shortcomings:
- Complex design of lugs, dimensions of which are required to
be closely monitored.
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- Higher chances of lever rod disassembly at higher loads due
to failure of even a single lug, which leads to pop out of the
ball.
- Complete lever assembly is required to be replaced in case of
any minor crack/failure of any of the lever assembly parts.
- Replacement of only lever as a spare part is not possible.
Further in the current lever assembly the gear lever (1) constitutes
a single piece with pivot ball (2) over molded thereto as shown in
fig. 2 which in turn is assembled to the lever assembly housing.
The lever, on which shift pin (3) is riveted at one end for connection
with the cable and other end of which, is attached to a shift knob
(4). It also has provision to hold one end of the boot in case of
threaded knob.
The knob is assembled onto lever by means of snap joint or
threaded joint followed by assembling boot to the knob, in case of
threaded knob and on the lever rod in case of snap fit type knob.
The method of assembling the boot to the Gear Shift lever Assy,
depends on type of joint i.e. snap or threaded joint.
Thus in the prior art attachment of knob to lever is followed by
fitting of boot, which causes problem in assembly. Further,
boot/knob can't be replaced at user's will.
Further, currently available configuration has the following
drawbacks:
- Lever ratio is not changeable as the lever rod parameters are
fixed.
- In case of threaded joint between lever rod and knob, the
assembly of knob is not possible at vehicle assembly line as
knob has to be assembled at supplier end only. This
consumes more time for assembly and also limits method
and type of boot (rubber or leather) for the boot attachment
to knob.
- Fixed boot colour/styling.
In view of the above, there is a need to develop a gear shift lever
assembly and a method of assembly thereof and a lever rod, which
can address the aforesaid issues and fulfill the requirement of the
present invention.
OBJECTS OF THE INVENTION
Primary object of the present invention is to provide a gear shift
lever assembly and a method of assembly thereof and a lever rod
which overcomes disadvantages associated with the prior art.
Another object of the present invention is to provide a gear shift
lever assembly and lever rod which is simple in construction.
Still another object of the present invention is to provide a gear
shift lever assembly and lever rod which can be assembled easily.
Yet another object of the present invention is to provide a gear shift
lever assembly and lever rod in which lever rod is replaceable.
SUMMARY OF THE INVENTION
According to this invention, there is provided a gear shift lever
assembly comprising lever rod with axle lever connected to shift
pin at one end together with a pivot ball at the joint of the lever rod
and axle lever wherein a threaded joint is provided at the interface
of socket and housing for assembling thereof.
Further according to this invention, there is provided method of
assembly for gear shift lever assembly comprising steps of:
- Joining the axle lever to main lever rod;
- Joining the shift pin to the subassembly thus obtained;
- Overmolding of pivot ball to subassembly as obtained above;
- Torqueing of socket liner to GSLA housing;
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- Assembly of lever sub assy to housing sub assembly by snap
fit.
Further according to this invention, there is provided a lever rod
for gear shift lever assembly comprising O.at least two parts with a
joint there between.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more
apparent from the ensuing description when read in conjunction
with the accompanjdng drawings of exemplary embodiments of
invention and wherein:
FIG. 1 shows: Gear shift lever assembly according to prior art;
FIG. lA shows: Enlarged view of conventional socket and
housing;
FIG. 2 shows: Conventional lever rod;
FIG. 3 shows: Gear shift lever assembly in accordance with
present invention;
FIG. 4 shows: Enlarged view of socket and housing of present
invention;
FIG. 5 shows: Novel lever rod of present invention;
FIG.6 shows: Male and female locking profile of lever rod
according to present invention.
DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE
TO THE ACCOMPANYING DRAWINGS
The present invention proposes gear shift lever assembly. In this
regard reference may be made to fig. 3, in which connection
between the socket and housing of the lever assembly is
established through threaded joint instead of conventionally
provided press fit type.
In order to accommodate the above, the socket (S) of lever
assembly is provided with a plurality of threads (Ti) on its outer
peripheral surface, which is torqued to corresponding threads (T2)
in the internal surface of hollow space (H) in housing (G) as best
seen in fig.4.Thereafter, the lever rod is assembled to the socket
and housing assembly through press fit.
Advantageous Features
- Better looseness, free play and strength due to threaded
joint.
- It is simple in construction involving easy assembly of parts.
- Lever rod is replaceable (for changing lever ratio etc) without
requiring to change the complete lever assembly.
The assembly process of the lever assembly is described stepwise
as follows:
- Joining the axle lever to main lever rod by welding;
- Joining the shift pin by riveting to the subassembly as
obtained in step 1;
- Overmolding of pivot ball to subassembly as obtained in step
2;
- Torqueing of socket liner to GSLA housing;
- Assembly of lever sub assy to housing sub assembly by snap
fit.
From the above, it can be clearly observed that the assembly
procedure of invention has been simplified.
Again according to the invention, the gear shift lever is divided into
two parts, for which reference may be made to fig. 5. The lever
comprises one part (1) and another part (2), which are assembled
through snap joint. Said one part comprises first part of the lever
rod (3) and another part is having second part of the lever rod (4).
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Said first part is further provided with a male locking profile (5) at
one end.
Second part (4) of the lever rod is connected to lever axle selection
(L) with a pivot ball (B) onto the joint of second part of lever rod (4)
and axle selection (L) as in fig. 5.
Now reference may be made to fig. 6,in which said ball (B) is
provided with corresponding female locking profile (6) for mating
with said male locking profile facing each other.
The complete lever rod becomes one single part after assembly of
both parts. The complete lever rod assembly is assembled to the
housing as per the usual arrangement.
The assembly procedure of the above involves fitting of boot
followed by assembly of lever-knob assy. This lets the user to
change colour and styling of knob and boot at will.
Advantageous Features
- Flexibility to use threaded type of knob along with any type
of boot without any special arrangement in the boot, whereas
in the current arrangement of lever rod either rubber boot or
leather boot with special arrangement can only be used.
- Fitting of boot in the vehicle assembly line instead of
supplier end with threaded type knob.
- The lever ratio of the system is changeable by changing the
top lever rod only thus giving the flexibility of variation in
load values at the knob as per the requirement.
- No requirement of using gear lock as the lever rod can be
detached whenever required, which makes the vehicle
immovable.
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- Knob/boot is changeable.
It is to be noted that the present invention is susceptible to
modifications, adaptations and changes by those skilled in the art.
Such variant embodiments employing the concepts and features of
this invention are intended to be within the scope of the present
invention, which is further set forth under the following claims:-

WE CLAIM:
1. A gear shift lever assembly comprising lever rod with axle
lever connected to shift pin at one end together with a pivot
ball at the joint of the lever rod and axle lever wherein a
threaded joint is provided at the interface of socket and
housing for assembling thereof.
2. A gear shift lever assembly as claimed in claim 1 wherein
outer peripheral surface of the socket comprising a plurality
of threads.
3. A gear shift lever assembly as claimed in claim 1 or 2
wherein the socket is assembled into hollow space of said
housing, internal surface of which is having multiple threads
corresponding to said threads of socket.
4. Method of assembly for gear shift lever assembly comprising
steps of:
- Joining the axle lever to main lever rod;
- Joining the shift pin to the subassembly thus obtained;
- Overmolding of pivot ball to subassembly as obtained above;
- Torqueing of socket liner to GSLA housing;
- Assembly of lever sub assy to housing sub assembly by snap
fit.
5. Method of assembly for gear shift lever assembly as claimed
in claim 4 wherein the joining of axle lever to main lever rod
is carried out by welding followed by joining the shift pin by
riveting.

6. A lever rod for gear shift lever assembly comprising atleast
two parts with a joint therebetween.
7. A lever rod for gear shift lever assembly as claimed in claim 6
wherein said one part comprises first part of lever rod with a
male locking profile at one end.
8. A lever rod for gear shift lever assembly as claimed in claim 6
or 7 wherein said another part comprises second part of the
lever rod connected to lever axle selection at one end with a
pivot ball onto the joint thereof.
9. A lever rod for gear shift lever assembly as claimed in any of
the preceding claims wherein said ball is provided with a
corresponding female locking profile facing the male locking
profile for joining therewith.
10. A gear shift lever assembly and a lever rod therefore as
claimed in any of the preceding claims is associated with the
advantageous features such as herein described.