FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
"IMPROVED GEAR SHIFT SYSTEM FOR CAB OVER ENGINE VEHICLE"
2. APPLICANT
. VE COMMERCIAL VEHICLES LTD., An Indian National having its place of business at 102, INDUSTRIAL AREA NO.i, PITHAMPUR-454775, DIST. DHAR MADHYA PRADESH, INDIA
3. PREAMBLE OF THE DESCRIPTION
The following specification describes this invention and the manner in which it is to be performed
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TECHNICAL FIELD
[001] The present subject matter relates to an improved gear shift system for cab over engine vehicle. Particularly, it provides a cabin floor mounted single rod type gear shift system, wherein adjustable locking arrangement for releasably locking together a gear shift lever and a gear shift rod in a motor vehicle having a preferably one end mounted on the cab floor directly and another end connected to the Transmission (T/M lever) lever.
BACKGROUND
[002] In conventional cab over engine vehicle, the common problem to remove the gear shift lever without touching the cabin. In normal practice, it has been seen that cabin required to tilt or to make a hallow framework on the cabin floor to remove the gear shift lever (GSL), since the gear shift lever is mounted on the chassis or on engine, wherein engine & chassis position are fixed. Hence the said system is complex, bulky in nature and not userfriendly.
[003] Further the existing single rod gear system is preferably not suitable for cab over engine vehicle, where there is a minimal or less clearance between cabin bottom floor and engine surface or engine is placed towards rear end of the cabin because while tilting the cabin for maintenance of vehicle parts, it is required larger or bigger framework on cabin floor for separation of gear shift system and cabin.
[004] In cab over engine type truck configuration, the mechanical single rod is preferable & best efficient option for gear shift mechanism. On end of Gear shifting linkage is mounted on the engine through bracket and the lever comes inside from the cabin, beside the driver seat for changing the gears. Another end of this linkage is connected to vehicle transmission shift lever.
[005] During the cabin tilting at its axis, a cut out is required on cabin floor which allows cab tilting when GSL is mounted on engine. The size of cab floor cut out depends on the vertical distance of engine top surface and the cab floor. Smaller is the vertical distance between cab floor and engine, bigger would be the cab floor cut out. Providing larger cut out on cab floor for GSL lever will incur huge cost penalty in

tooling development and also this will make cab floor weaker and also sealing this cut out from engine heat, hot air & vibration is the challenge.
[006] When engine is placed toward extreme rear side of cab, the gear shift linkage (GSL) mounting bracket would have larger over hang from its mounting position on engine and making a rigid and stiff bracket is a challenge.
[007] With all these challenges providing a single rod type gear shift mechanism on cab over engine type truck configuration is close to impossible when cab and engine are place at their extremities i.e when gap between engine & cabin is less and engine is placed toward rear side of cabin.
[008] To overcome above challenges/problems, an adjustable locking arrangement for releasably locking together a gear shift lever and a gear shift rod in a motor vehicle having a preferably forward-tipping cab, in which arrangement the gear shift lever is articulated in the cab by way of a universal joint and is furthermore provided with a gear shift movement-transmitting section having a shaft which pivotally supports a moveable locking part. However the limitations with the above such system is that it is cumbersome and complex system required close welding position tolerance & closed maintained profile to maintain angle Ψ between locking guide heel and locking surface.
[009] Therefore there is an unmet need of a system, which is single system and mounted on cabin floor directly and provide effective mechanism to operate the gear shifting and cabin tilting operation to make the gear shift level system simple, user-friendly and technology friendly without providing bigger cut out on cabin floor.
SUMMARY OFTHE SUBJECT MATTER
[0010] In conventional cab over engine vehicle, it is a major challenge to
remove the gear shift lever without touching the cabin. To overcome above challenge, it is required to tilt the cabin or make a hallow framework on the cabin floor to remove the gear shift lever (GSL), as the gear shift lever is mounted on the chassis or on engine, wherein engine & chassis position are fixed. Hence the said system is complex, bulky in nature and not user friendly.

[oon] The present subject solve the aforementioned and other problems
by providing a gear shift level system mounted on cabin floor of the Engine or chassis of the vehicle. The gear shift has two ends-first end and second end. The first end is mounted on the cab floor directly and second end is connected to the transmission lever of the vehicle. The gear shift lever (GSL) is mounted on the cabin floor directly, hence this arrangement is independent of the placement of the engine on the vehicle. Therefore engine vibration and hot air does not affect the system, as the system is directly mounted on the cabin floor.
[0012] In one embodiment, the present subject matter discloses the gear
shift lever. The gear shift lever facilitate the tilting of the cab through a unique concept of cam & follower mechanism. During the tilting operation of the cabin the cam uplifts the follower, which is directly connected to the interlock mechanism. This interlock mechanism locks the outer hollow rod and inner rod with its ramp & wedge profile.
[0013] In another embodiment, the present subject facilitate gear shifting
operation, wherein a pin is provided on the bottom part of shifter lever which pushes the inner rod at its slot profile enabling the forward gear shifting and interlock provided at the outer hollow rod locks the inner rod at its ramp profile and pulls the inner rod enabling the backward gear shifting. Further here the interlock is loaded with a spring to ensure the contact of interlock with inner rod during vehicle driving condition. In further embodiment, the inner rod is provided with wedge profile on its top for backward gear shifting and a slot profile in its front for forward gear shifting and for gear gate selection. Here the single rod is made into two piece rod in rod construction; which works like outer-inner associated tube during cabin tilting operation. Further to reduce the friction between outer and inner rod, the system is integrated with one bush unit in between inner rod and outer rod to minimize the physical connection between outer-inner layer made-up of metal thereby minimal friction and dampen noise during gear shift operation caused due to metal rubbing. Further to keep system dust free, one expandable bellow is introduced at end of hollow rod to restrict the dust entry between the two rods. As dust will increase friction between rods during cab tilting operation.

[0014] Further a spherical type ball joint is provided on the floor mounted
lever with optimized lever diameter and spherical joint angle to ensure that all gears are shifting and spherical joint is not getting lock in any gear condition. Also spherical joint is optimized in such a way that gears are not popping out/jump out in any type of vehicle driving conditions.
[0015] In another embodiment, the present subject matter discloses the
operation of the gear shift lever by following ways:
[0016] Gear shifting conditions:
[0017] The improved gear shift lever is designed in such a way that in cab
down condition all forward, backwards will be shifted efficiently and also all gates will be selected smoothly. During forwards gear shifting condition the pin connected to shifter lever pushes the slot profile on the inner rod ensuring the backward gear shifting at transmission end. Further during the backward gear shifting by driver, the interlock mechanism provided on the hollow rod is pulling the inner rod through the optimized wedge profile and ensures forward gear shifting at transmission end. For H pattern gate selection, shifter lever pin which is in contact with inner rod slot profile select the different gate on T/M through the reaction rod mechanism provided at T/M end of the rod.
[0018] Cab tilting operation:
[0019] For cabin tilting operation, cam & follower mechanism is provided.
In cabin down condition, this cam & follower profile is not in contact. After initial few degrees of cab tilting, cam profile comes in contact with follower. Follower gets lifted up which in turn lifts up the interlock which is connecting the inner and outer telescopic type rods. When interlock lifted up, the inner rod is free to slides outside the outer rod behaving like telescopic arrangement. When inner rod slides inside of the outer rod the cabin is totally free for tilting at its axis by its designed value of rotation. During cabin down condition, the cam starts leaving the contact with follower and simultaneously the inner rod slides inside the outer rod. This finally establishes the interlock contact with wedge profile of inner rod.
[0020] Noise free operation:

[0021] To reduce the clearance between inner and outer rod a polyamide
with glass filled bush is used. This also dampens all the noise generated during gear shifting due to contact of these 2 rods.
[0022] Dust entry protection: (FIG.5)
[0023] During the cabin tilting operation, the telescopic arrangement of
two rods opens up to atmosphere. Dust will accumulate on the surface of inner rod which is exposed to atmosphere due to telescope opens up. Expandable bellow is provided at the end of the outer rod to ensure that all the unwanted particles gets wiped off when outer rod slides inside inner rod during cab down condition.
[0024] It is to be understood that other embodiments of the present
disclosure will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described only various embodiments of the disclosure by way of illustration. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF DRAWINGS
[0025] Aspects of the present disclosure are illustrated by way of example,
and not by way of limitation, in the accompanying drawings, wherein:
[0026] FIG. 1 is a block diagram illustration of a gear shift lever system in
accordance with one embodiment of the present disclosure.
[0027] FIG. 2 is a block diagram illustration of various components of the
gear shift lever system in accordance with one embodiment of the present
disclosure. .
[0028] FIG. 3 is a block diagram illustration of Bush & Bellow arrangement
of the gear shift lever system in accordance with one embodiment of the present disclosure.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0029] The present disclosure relates generally to gear shift lever system
and more particularly, to gear shift lever system, wherein it a single rod mounted on

cabin floor, wherein adjustable locking arrangement for releasably locking together a gear shift lever and a gear shift rod in a motor vehicle having a preferably one end mounted on the cab floor directly and another end connected to the Transmission (T/M lever) lever.
[0030] Referring to FIG. 1 illustrated is of a gear shift lever system 100 in
accordance with one embodiment of the present disclosure. The gear shift system comprises shifter lever with spherical joint 101, configured to engage with cabin mounting bracket 103 through ball joint. Here shift lever with spherical joint 101 assist towards shifting & selection of gears. Further cabin mounting bracket 103 hold on the cabin bottom floor to support the spherical ball. Cam profile 105 is connected to the lower end of shifter lever and come in contact with follower profile during cabin tilting operation. After certain degree of cabin tilting, cam start uplifting the follower and hence interlock gets lifted up as it is connected to follower profile by a pinned joint, interlock (not shown in FIG. i), pin (not shown in FIG. 1) is connected to the lower part of shifter lever where it is touching the front profile of hollow rod and facilitate during the backward gear shifting in in the gear selection. Outer hollow rod 107 guides the inner rod 109 & facilitates the interlock movement and holds the follower profile. Inner rod 109 is having the front & wedge profile which helps in forward & backward gear shifting with gear gate selection. Front profile (not shown in FIG. 1) gets connected to the pin and enables the forward gear shifting. Wedge section (not shown in FIG. 1) get locked through interlock and enables backward gear shifting. Below is the dust preventing member between outer & inner rod. Transmission end adjustable ball joint transfers the shifting force to the transmission lever to ensure its movement for gear shifting & selection. Polyamide bush (not shown in FIG. a) avoids the metallic rubbing of inner & outer rod to dampen the noise during shifting. Spring (not shown in FIG. 1) provides force to the interlock to keep it in its position in the wedge profile condition.
[0031] FIG. 2 illustrated various components of the gear shift lever system
100 as illustrated in FIG. 1 in accordance with one embodiment of the present

disclosure. The component of gear shift lever as shown in FIG. 2A comprises of cabin mounting bracket hold on the cabin bottom floorto support the spherical ball. Cam profile 201 is connected to the lower end of shifter lever and come in contact with follower profile 203 & this follower is pinned to the interlock during cabin tilting. Further the component of gear shift lever as shown in FIG. 2B comprises of pin 205 is connected to the lower part of shifter lever where it is touching the front profile of hollow rod and facilitate during the backward gear shifting in in the gear selection. Spherical ball joint isprovided on the floor mounted lever with optimized lever diameter and spherical joint angle to ensure that all gears are shifting and spherical joint is not getting lock in any gear condition & gear are not popping /jumping out in vehicle driving condition. Interlock is pinned to the follower profile and get lifted up to release inner rod wedge profile 207 during cabin tilting operation. Outer hollow rod guides the inner rod 211 & facilitates the interlock movement and holds the follower profile. The component of gear shift lever as shown in FIG. 2C comprises of pin is connected to the lower part of shifter lever where it is touching the front profile of hollow rod and facilitate during the backward gear shifting in in the gear selection. Spring 213 provides force to the interlock to keep it in its position in the wedge profile to ensure interlock connection with wedge profile of inner rod in all vehicle driving condition. Follower profile comes in contact with cam profile during cabin tilting operation and it lifts the interlock which is pinned joint with follower. Interlock is pinned to the follower profile and get lifted up to release inner rod wedge profile during cabin tilting operation.
[0032] FIG. 3 is a block diagram illustration of Bush & Bellow arrangement
of the gearshift lever system in accordance with one embodiment of the present disclosure. The bush 301 and bellow 303 arrangement minimizer the friction between outer and inner components of the gearshift lever system.
[001] It would become abundantly clear to a person in the art, after reading this specification that the present subject matter also provides an improved gear shift system for cab over engine and method of construction thereof, preferably suitable for commercial vehicle without departing from the spirit of the present subject matter. While the subject matter may be susceptible to various modifications and

alternative forms, specific embodiments have been shown by way of example in the drawings and have been described herein. Alternate embodiments or modifications may be practiced without departing from the spirit of the present subject matter. The drawings shown are schematic drawings and may not be to the scale. While the drawings show some features of the subject matter, some features may be omitted. Alternatively, in some other cases some features may be emphasized while others are not. Further, the methods disclosed herein may be performed in manner and/or order in which the methods are explained. Alternatively, the system/method may be performed in manner or order different than what is explained without departing from the spirit of the present subject matter. It should be understood that the subject matter is not intended to be limited to the particular forms disclosed. Rather, the subject matter is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter.

What is claimed is:
1. An improved gear shift system for cab over engine system of a vehicle comprising:
a) a first end; wherein first end is mounted on cab floor directly
b) a second end; wherein second end is connected to a transmission lever of a vehicle;
wherein gear shift lever is mounted on the cabin floor directly, hence it has independent arrangement
2. The improved gear shift system as claimed in claim i, wherein improved gear shift system facilitate the tilting of the cab through cam and follower mechanism.
3. The improved gear shift system as claimed in claim 1, wherein improved gear shift system comprises an interlock system.
4. A method of operation of improved gear shift system for cab over engine system of a the vehicle as claimed in claim 1 comprising:

c) a first end; wherein first end is mounted on cab floor directly
d) a second end; wherein second end is connected to a transmission lever of a vehicle;
wherein gear shift lever is mounted on the cabin floor directly, hence it has independent arrangement
5. The method of operation as claimed in claim 4, wherein the operation comprising
gear shifting condition, Cab tilting condition to provide noise free and dust free operation.