Description:FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]

TITLE OF INVENTION
A Gearshift Lever Assembly for a Manual Transmission Vehicle

APPLICANT
MAHINDRA & MAHINDRA LIMITED, an Indian company, having its address at Mahindra & Mahindra Limited, Mahindra Research Valley, Mahindra World City, Plot No:41/1, Anjur P.O., Chengalpattu, Tamil Nadu – 603004, India

PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
[001] The present invention relates to a gearshift lever assembly. More particularly, the present invention is directed toward a gearshift lever assembly for a manual transmission vehicle.

BACKGROUND OF THE INVENTION
[002] Conventionally in motor vehicles, especially in rear-wheel-drive vehicles, the gear shifter mechanism is connected to the transmission via a direct shift linkage member from the transmission. Because of the direct connection between the transmission and the gear shifter mechanism, the gear shifter mechanism experiences excessive vibrations, as the vibrations of the power train are transferred to the gear knob of the gear shifter mechanism. Continuous and excessive vibration of the gear knob, which the rider uses to perform a gearshift operation causes fatigue and rider discomfort.
[003] In conventional attempts to overcome the aforementioned issues, a shift by cable technology was introduced in rear-wheel-drive platforms as an alternative to the conventional gear shifter mechanisms with direct shift linkage members. In shift by cable mechanisms, generally, two shift cables are connected between the transmission and the gear shifter mechanism. Herein, one end of the shift cables hangs from the underside of the gear shifter lever and the other end of the shift cables lead to the gearbox. Thereafter, depending on the position of the gear shifter lever, the gears are selected by moving the shift cables. Since conventional gear shift linkage members are solid members which have a lower freedom of movement, provision of shift cables ensure a more precise gear switching operation.
[004] However, the usage of shift cables in gear shifter mechanisms requires a higher number of components such as additional linkages and dampers. Due to this, and due to the shift cables not being rigid in addition to the intricate routing of the shift cables, the shift cable mechanisms have excessive free play in once the gear position is engaged. This free play is felt in the gear knob by the rider, which deteriorates riding experience and overall feel in the gear shifting operation.
[005] Conventionally, free play in the shift cable mechanisms is controlled by techniques such as leverage, component fits and rubber damper optimizations. In that, usage of leverage reduction to reduce the free play results in an increase in the shift loads causing the rider discomfort and a hard feel during gear shift. Similarly, usage of component fit wherein a tight fit is provided in the interface of the components leads to non- returnability of shift lever to the neutral, leading to inconsistent shifts. Non returnability also leads to a phenomenon called synchro preloading and subsequent gear crash. Similarly, usage of rubber dampers and optimisation of damper characteristics to reduce the free play by making the system rigid. Overall, usage of these techniques compromises the performance requirements or the shift quality.
[006] Thus, there is a need in the art for a gearshift lever assembly which addresses at least the aforementioned problems.

SUMMARY OF THE INVENTION
[007] In one aspect, the present invention relates to a gearshift lever assembly for a manual transmission vehicle. The gearshift lever assembly has a gearshift shaft extending from a gear knob provided in the vehicle, and the gearshift shaft is movable in different positions for shifting gear positions in the vehicle. A magnet is provided on a bottom end of the gearshift shaft. A base member is provided below the bottom end of the gearshift shaft. The base member has a first metal plate positioned such that the magnet aligns with the first metal plate when the gear position is in a neutral position. The base member has a second metal plate spaced apart from the first metal plate and the second metal plate is positioned such that the magnet aligns with the second metal plate when the gear position is in an odd numbered gear position. The base member has a third metal plate spaced apart from the first metal plate and the third metal plate is positioned such that the magnet aligns with the third metal plate when the gear position is in an even numbered gear position. Hereby, a magnetic force is created when the magnet aligns with any of the metal plates to eliminate any free play of the gearshift shaft.
[008] In an embodiment of the present invention, the gearshift lever assembly has a non-metallic casing for holding the magnet.
[009] In a further embodiment of the present invention, the non-metallic casing is over moulded onto the bottom end of the gearshift shaft. In an alternative embodiment, the non-metallic casing is press fit onto the bottom end of the gearshift shaft.
[010] In a further embodiment of the present invention, the magnet is held in the non-metallic casing by means of an adhesive.
[011] In a further embodiment of the invention, the first metal plate, the second metal plate and the third metal plate are made up of a ferromagnetic material.
[012] In a further embodiment of the invention, the second metal plate is positioned such that the magnet aligns with the second metal plate when the gear position is in an odd numbered gear position or a reverse gear position. In an alternative embodiment, the third metal plate is positioned such that the magnet aligns with the third metal plate when the gear position is in an even numbered gear position or the reverse gear position.

BRIEF DESCRIPTION OF THE DRAWINGS
[013] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates a perspective view of a gearshift lever assembly, in accordance with an embodiment of the invention.
Figure 2A illustrates a side view of the gearshift lever assembly with Section A-A and Figure 2B illustrates a sectional view of the gearshift lever assembly along Section A-A, in accordance with an embodiment of the invention.
Figure 3 illustrates a perspective view of a base member of the gearshift lever assembly, in accordance with an embodiment of the invention.
Figure 4 illustrates a top view of the first metal plate, second metal plate and third metal plate of the base member, in accordance with an embodiment of the invention.
Figure 5 illustrates a magnified sectional view of the gearshift lever assembly along Section A-A, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION
[014] The present invention is directed towards a gearshift lever assembly. More particularly, the present invention is directed toward a gearshift lever assembly for a manual transmission vehicle.
[015] Figure 1 illustrates a perspective view of a gearshift lever assembly 100 for a manual transmission vehicle in accordance with an embodiment of the invention. As illustrated in Figure 1, the gearshift lever assembly 100 comprises a gearshift shaft 110 that extends from a gear knob (not shown) provided in the vehicle. The gearshift shaft 110 is movable in different positions for shifting gear positions in the vehicle. Herein, to perform a gearshift operation, the rider of the vehicle holds the gear knob and moves the gear knob, thereby moving the gearshift shaft 110 into different positions for performing the gearshift operation into the desired gear. In an embodiment, as illustrated, the gearshift shaft 110 extends substantially downward from the gear knob.
[016] In an embodiment, as referenced in Figure 2, the gearshift shaft 110 is housed in a shifter housing 112. The gearshift shaft 110 is housed in the shifter housing 112 by means of a shifter pivot ball 114. The gearshift shaft 110 is attached on to the shifter pivot ball 114 and the provision of the shifter pivot ball 114 allows the gearshift shaft 110 to pivotably move inside the shifter housing 112. Pivotal movement of the gearshift shaft 110 into different positions thus allows engagement of different gears to perform the gearshift operation.
[017] As further illustrated in Figures 2 and 3, the gearshift lever assembly 100 comprises a magnet 120 that is provided on a bottom end 110A of the gearshift shaft 110. Further, the gearshift lever assembly 100 has a base member 130 that is provided below the bottom end 110A of the gearshift shaft 110. The base member 130 is space apart from the bottom end 110A of the gearshift shaft 110 to avoid contact between the base member 130 and gearshift shaft 110 and thereby avoid interference, scratchiness or noise between the base member 130 and the gearshift shaft 110. The distance between the bottom end 110A of the gearshift shaft 110 and the base member 130, and thus the magnet 120 and the base member 120 is at least 0.5 mm and the same can be varied depending upon the strength of the magnet 120. Further, the base member 130 is coupled to a bottom portion of the shifter housing 112 with fasteners such as, self-tightening screws. The base member 130 comprises a first metal plate 132. The first metal plate 132 is positioned such that the magnet 120 aligns with the first metal plate 132 when the gear position is in a neutral position (also referenced in Figure 4). Accordingly, when the gearshift shaft 110 is moved into a position which corresponds to a neutral gear, the magnet 120 aligns with the first metal plate 132 and a magnetic force is created between the magnet 120 and the first metal plate 132. The magnetic force between the magnet 120 and the first metal plate 132 holds the gearshift shaft 110 in place when the position of the gearshift shaft 110 corresponds to neutral gear position until an external force is applied, thereby eliminating free play of the gearshift shaft 110 in neutral gear position.
[018] The base member 130 further has a second metal plate 134 spaced apart from the first metal plate 132. The second metal plate 134 is positioned such that the magnet 120 aligns with the second metal plate 134 when the gear position is in odd numbered gear positions. Accordingly, when the gearshift shaft 110 is moved into a position which corresponds to an odd numbered gear, say, 1, 3, 5 etc and so on (also referenced in Figure 4), the magnet 120 aligns with the second metal plate 134 and a magnetic force is created between the magnet 120 and the second metal plate 134. The magnetic force between the magnet 120 and the second metal plate 134 holds the gearshift shaft 110 in place when the position of the gearshift shaft 110 corresponds to an odd numbered position until an external force is applied, thereby eliminating free play of the gearshift shaft 110 in odd numbered gear positions.
[019] The base member 130 further has a third metal plate 136 that is spaced apart from the first metal plate 132. The third metal plate 136 is positioned such that the magnet 120 aligns with the third metal plate 136 when the gear position is in even numbered gear positions. Accordingly, when the gearshift shaft 110 is moved into a position which corresponds to an even numbered gear, say, 2, 4, 6 (referenced in Figure 4) etc and so on, the magnet 120 aligns with the third metal plate 136 and a magnetic force is created between the magnet 120 and the third metal plate 136. The magnetic force between the magnet 120 and the third metal plate 136 holds the gearshift shaft 110 in place when the position of the gearshift shaft 110 corresponds to an even numbered position until an external force is applied, thereby eliminating free play of the gearshift shaft 110 in even numbered gear positions. Thus as a whole, a magnetic force is created when the magnet 120 aligns with any of the metal plates 132, 134, 136 to eliminate any free play/movement of the gearshift shaft 110. In an embodiment, the first metal plate 132, the second metal plate 134 and the third metal plate 136 are over-moulded on to the base member 130. The base member 130 is preferably glass fibre reinforced polyamide.
[020] In operation, the magnet 120 aligns with the first metal plate 132 and a pre-determined force would be required for moving the gearshift shaft 110 into a different gear position. For example, the magnet 120 is selected such that the magnetic force between the magnet 120 and the base member 130 is in the range of 60N to 96N and the force required at the knob of the gearshift shaft 110 for moving the gearshift shaft 110 ranges between 8N to 12N. The magnet 120 can be selected from a range of permanent magnets, such as alnico magnets that are primarily made up of a combination of aluminium, nickel and cobalt but can also include copper, iron and titanium. The magnet 120 by way of magnetic force between the magnet 120 and the first metal plate 132 essentially pulls down the gearshift shaft 110, thereby restricting any movement of the gearshift shaft 110 unless the predetermined force is applied on the gear knob, and thus eliminating free play. Similarly, at different gears, the magnet 120 aligns with the second metal plate 134 or the third metal plate 136 at different gear positions, and again, the predetermined force would be required to change the position of the gearshift shaft 110, thus eliminating free play. The second metal plate 134 and the third metal plate 136 being spaced apart from the first metal plate 132 as illustrated in Figure 4 also ensures that during changing between two gear positions, no such force or interaction is acting on the magnet 120 which would pull or hold the gearshift shaft 110, which would have otherwise made changing of gears rather force intensive and detrimental to the user.
[021] In an embodiment as illustrated in Figure 5, for provision of the magnet 120 on the bottom end 110A of the gearshift shaft 110, a non-metallic casing 140 is provided for holding the magnet 120. In an embodiment, the magnet 120 is held inside the non-metallic casing 140 by means of an adhesive. The non-metallic casing 140 ensures that the magnet 120 is held in place without any unnecessary loss in the magnetic properties of the magnet 120. In an embodiment, the non-metallic casing 140 is over moulded onto the bottom end 110A of the gearshift shaft 110. In an alternative embodiment, the non-metallic casing 140 is press fit onto the bottom end 110A of the gearshift shaft 110.
[022] In an embodiment, as referenced in Figure 4, the second metal plate 134 is positioned such that the magnet 120 aligns with the second metal plate 134 when the gear position is in an odd numbered gear position or a reverse gear position. In an alternative embodiment, the third metal plate 136 is positioned such that the magnet 120 aligns with the third metal plate 136 when the gear position is in an even numbered gear position or the reverse gear position. This ensures that free play in the gearshift shaft 110 is eliminated when the gearshift shaft 110 is in a position corresponding to the reverse gear position, along with all the other gear positions.
[023] Advantageously, the present invention provides for a gearshift lever assembly in which free play is eliminated at all the gear positions including the neutral gear position and the reverse gear position, thus eliminating the problem of free play especially prevalent in shift cable transmissions. The present invention achieves the elimination of free play while ensuring that the force required to shift from one gear position to another is not unnecessarily increased, thus ensuring better overall gearshift feel and quality perception.
[024] Further, especially in rear-wheel-drive vehicles wherein the shift cables are longer, the present invention provides for elimination of free play which allows for lower wear and tear of the components. The present invention achieves the elimination in free play while being simple and thus being affordable.
[025] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.
, Claims:WE CLAIM:
1. A gearshift lever assembly (100) for a manual transmission vehicle, the gearshift lever assembly (100) comprising:
a gearshift shaft (110) extending from a gear knob provided in the vehicle, the gearshift shaft (110) movable in different positions for shifting gear positions in the vehicle;
a magnet (120) provided on a bottom end (110A) of the gearshift shaft (110); and
a base member (130) provided below the bottom end (110A) of the gearshift shaft (110), the base member (130) comprising:
a first metal plate (132) positioned such that the magnet (120) aligns with the first metal plate (132) when the gear position is in a neutral position;
a second metal plate (134) spaced apart from the first metal plate (132), the second metal plate (134) positioned such that the magnet (120) aligns with the second metal plate (134) when the gear position is in an odd numbered gear position; and
a third metal plate (136) spaced apart from the first metal plate (132), the third metal plate (136) positioned such that the magnet (120) aligns with the third metal plate (136) when the gear position is in an even numbered gear position, the magnet (120) when aligned with any of the metal plates (132, 134, 136) causes a magnetic force to be created between the magnet and the respective metal plate restricting movement of the gearshift shaft until an external force is applied, thereby eliminating/reducing any free play of the gearshift shaft (110).

2. The gearshift lever assembly (100) as claimed in claim 1, comprising a non-metallic casing (140) for holding the magnet (120).

3. The gearshift lever assembly (100) as claimed in claim 2, wherein the non-metallic casing (140) is over moulded onto the bottom end (110A) of the gearshift shaft (110).

4. The gearshift lever assembly (100) as claimed in claim 2, wherein the non-metallic casing (140) is press fit onto the bottom end (110A) of the gearshift shaft (110).

5. The gearshift lever assembly (100) as claimed in claim 2, wherein the magnet (120) is held in the non-metallic casing (140) by means of an adhesive.

6. The gearshift lever assembly (100) as claimed in claim 1, wherein the first metal plate (132), the second metal plate (134) and the third metal plate (136) are made up of a ferromagnetic material.

7. The gearshift lever assembly (100) as claimed in claim 1, wherein the second metal plate (134) is positioned such that the magnet (120) aligns with the second metal plate (134) when the gear position is in an odd numbered gear position or a reverse gear position.

8. The gearshift lever assembly (100) as claimed in claim 1, wherein the third metal plate (136) is positioned such that the magnet (120) aligns with the third metal plate (136) when the gear position is in an even numbered gear position or the reverse gear position.

Dated this 21st day of March 2023
MAHINDRA & MAHINDRA LIMITED
By their Agent & Attorney

(Janaksinh Jhala)
of Khaitan & Co
Reg No IN/PA-2193