FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10 and Rule 13]
“A STEERING SHAFT ASSEMBLY FOR A VEHICLE”
Name and Address of the Applicant:
TATA MOTORS LIMITED an Indian company having its registered office at Bombay house, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001, Maharashtra, INDIA,
Nationality: India
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
Present disclosure in general relates to a field of steering systems for a vehicle. More particularly, the disclosure relates to a steering shaft assembly configured to maintain a required position of a steering wheel.
BACKGROUND OF THE DISCLOSURE
Steering system is one of the essential systems in manoeuvring a vehicle in a required direction. The steering system gives control of a vehicle in various speed ranges by turning front wheels of the vehicle in the required direction. The steering system generally comprises a steering wheel coupled to a steering gear box through a steering shaft assembly. The input of the steering wheel is transmitted to the steering gearbox through the steering shaft assembly and to the front wheels. The steering gearbox is further connected to one or more members such as a tie rods that are further coupled to steering knuckles attached to the front wheels. The rotation of the steering wheel reciprocates the tie rods and the steering knuckles, to turn the front wheels to a left and a right direction. The front wheels of the vehicle are at a straight-ahead position when the steering wheel is at a home position to move or propel the vehicle in a straight direction. The straight ahead position refers to a condition of a vehicle in which the front wheels are positioned to be tracked in a straight direction i.e. in a forward direction or in a rearward direction.
Typically, the steering wheel includes a hollow cylindrical mounting portion which is mounted on one end of the steering shaft. The steering wheel tends to skew from its home position while its mounted on the steering shaft. This happens due to improper engagement of the hollow cylindrical portion with engagement portion defined at the one end of the steering shaft. This leads to improper steering of the vehicle and gives less control or feedback to a driver about direction of the vehicle. For example, when the driver maintains the steering wheel at the home position, the front wheels are deviated from the straight-ahead position which prevents the movement of the vehicle to track in a straight direction. Consequently, this puts the driver along with passengers at risk of accidents due to steering input errors.
Generally, in order to obtain this precise alignment between the steering wheel and the vehicle wheels, the steering wheel has to be removed from a steering column and then reinstalled in order

to obtain the desired precise alignment. Conventionally, there also exists a setup in which the steering shaft is divided into two threaded shafts which may be radially adjusted relative to one another to orient the steering wheel. This radial adjustment is done by the adjusting means which is basically a nut in contact with one of the two threaded shafts for radial adjustment. However, strength of this assembly of the two threaded shafts is not so high due to the threaded engagement of the two threaded shafts which may get deviated upon accidental movement of the nut. Also, the accurate alignment of the steering wheel to the home position cannot be achieved with this configuration.
Hence, present disclosure is directed to solve one or more limitations stated above or any other limitations associated with the prior art.
SUMMARY OF THE DISCLOSURE
The one or more shortcomings of the prior art are overcome by a steering shaft assembly as claimed and additional advantages are provided through the provisions as claimed in the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein.
Present disclosure discloses a steering shaft assembly for a vehicle, the steering shaft assembly comprises a first shaft defined with a first threaded portion at one end and a plurality of first serrations at another end opposite to the one end, wherein the plurality of first serrations is configured to receive a portion of a steering wheel. A second shaft is defined with a locking portion at one end configured to receive the first threaded portion, wherein the locking portion is defined with internal threads that engage with the first threaded portion to couple the second shaft with the first shaft. At least one bush mounted on the first shaft, the at least one bush is defined with at least one mating surface to engage with the second shaft. At least one locking nut is disposed in contact with the at least one bush, the at least one locking nut is configured to apply axial load on the at least one bush in a first direction to engage the at least one bush with the second shaft. The first shaft is radially adjusted with respect to the second shaft upon actuation of the at least one locking nut in a second direction to selectively orient the steering wheel.
In an embodiment, the plurality of first serrations is configured to receive a mounting portion of a steering wheel to rotatably mount the steering wheel on the first shaft.

In an embodiment, the first shaft is defined with a plurality of second serrations on a circumference of the first shaft and a second threaded portion is defined adjacent to the plurality of second serrations to receive the at least one locking nut.
In an embodiment, the at least one bush is defined with a plurality of internal serrations to engage with the plurality of second serrations.
In an embodiment, the second shaft is defined with a first knurling on an end surface of the locking portion to engage with the mating surface defined on the at least one bush.
In an embodiment, the mating surface is defined with a second knurling complementary to the first knurling to engage the at least one bush with the second shaft. In an embodiment, the damping member is configured to absorb the torsional and shock loads subjected on the drive shaft to prevent damage to the coupling.
In an embodiment, the first direction is along an axis defined in a longitudinal direction of the first shaft and the second direction is defined opposite and away from to the first direction.
In an embodiment, the plurality of first serrations is angled ranging between 2-5° with respect to the axis.
In one non limiting embodiment of the present disclosure, a vehicle is disclosed. The vehicle comprises a steering wheel defined in a home position. A steering unit is connected to at least one of front and rear wheels of the vehicle. A steering shaft assembly is configured to couple the steering wheel at one end and the steering unit at another end. The steering shaft assembly comprises a first shaft defined with a first threaded portion at one end and a plurality of first serrations at another end opposite to the one end, wherein the plurality of first serrations is configured to receive a portion of a steering wheel. A second shaft is defined with a locking portion at one end configured to receive the first threaded portion, wherein the locking portion is defined with internal threads that engage with the first threaded portion to couple the second shaft with the first shaft. At least one bush mounted on the first shaft, the at least one bush is defined with at least one mating surface to engage with the second shaft. At least one locking nut is disposed in contact with the at least one bush, the at least one locking nut is configured to apply axial load on the at

least one bush in a first direction to engage the at least one bush with the second shaft. The first shaft is radially adjusted with respect to the second shaft upon actuation of the at least one locking nut in a second direction to selectively orient the steering wheel to the home position.
In an embodiment, the home position of the steering wheel corresponds to a movement of the vehicle in a straight direction by the steering unit upon actuation of the steering wheel.
Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features and characteristics of the disclosure are explained herein. The embodiments of the disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawing in which:
Fig. 1 illustrates a sectional front view of a steering shaft assembly in accordance with an embodiment of the present disclosure.
Fig. 2 illustrates an exploded view of the steering shaft assembly in accordance with an embodiment of the present disclosure.
Fig. 3 illustrates a perspective view of a first shaft of the steering shaft assembly in accordance with an embodiment of the present disclosure.
Fig. 4 illustrates a perspective view of a second shaft of the steering shaft assembly in accordance with an embodiment of the present disclosure.
Fig. 5 illustrates a perspective view of at least one bush of the steering shaft assembly in accordance with an embodiment of the present disclosure.

Fig. 6 illustrates a perspective view of the steering shaft assembly of a vehicle in accordance with an embodiment of the present disclosure.
Figs. 7a, 7b and 7c illustrates a steering wheel position with respect to a central axis (A-A) of a steering wheel corresponding to a straight-ahead position of the vehicle .
The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the disclosure.
The terms “comprises,” “comprising,” or any other variations thereof, are intended to cover a non¬exclusive inclusion, such that a setup, device or process that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or process. In other words, one or more elements in a system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
The present disclosure relates to a steering shaft assembly for a vehicle. Generally, a steering shaft is used in vehicles for transmitting the rotating motion of a steering wheel to a steering unit which

is responsible for turning front wheels of the vehicle. The steering wheel is mounted at one end of the steering shaft. In general, the steering wheel tends to skew from its home position while it is mounted on the steering shaft. This happens due to improper engagement of the hollow cylindrical portion with engagement portion defined at the one end of the steering shaft. This leads to improper steering of the vehicle and gives less control or feedback to a driver about direction of the vehicle. Consequently, this puts the driver along with passengers at risk of accidents due to steering input errors.
In view of the above stated limitations, the present disclosure discloses a steering shaft assembly for a vehicle, the steering shaft assembly comprises a first shaft defined with a first threaded portion at one end and a plurality of first serrations at an other end opposite to the one end. The plurality of first serrations are configured to receive a portion of a steering wheel. A second shaft is defined with a locking portion at one end configured to receive the first threaded portion, and the locking portion is defined with internal threads that engage with the first threaded portion to couple the second shaft with the first shaft. At least one bush is mounted on the first shaft, and is defined with at least one mating surface to engage with the second shaft. At least one locking nut is disposed in contact with the at least one bush, the at least one locking nut is configured to apply axial load on the at least one bush in a first direction to engage the at least one bush with the second shaft. The first shaft is radially adjusted with respect to the second shaft upon actuation of the at least one locking nut in a second direction to selectively orient the steering wheel. The present disclosure also discloses a vehicle having the steering shaft assembly.
The following paragraphs describe the present disclosure with reference to Figures. 1a to 7c. In the figures, the same element or elements which have similar functions are indicated by the same reference signs.
Referring to Figs. 1 and 2 which illustrates a sectional front view of a steering shaft assembly (100) [hereinafter referred to as the assembly (100)] for a vehicle. The assembly (100) is disposed within a steering column (9) of a vehicle about a central axis (A-A) defined along a longitudinal direction of the steering column (9). The assembly (100) among other components include a first shaft (2), a second shaft (8), at least one bush (14) and a locking nut. As shown in fig. 3, the first shaft (2) is defined with a body (5) and a threaded portion (4) at one end of the body (4). The threaded portion

(4) comprises a plurality of external threads defined on an outer surface of the first shaft (2). A plurality of first serrations (6) are defined at another end of the first shaft (2) which is opposite to the one end. The plurality of first serrations (6) are configured to receive a mounting portion (21) of a steering wheel (20). In an embodiment, the mounting portion (21) may include a hollow cylindrical column with a plurality of internal serrations which are configured to match with the plurality of first serrations on the first shaft. In an embodiment, the steering wheel (20) is mounted on the one end of the first shaft (2) by fastening the mounting portion (21) of the steering wheel (20) about the plurality of first serrations (6). In an embodiment, the plurality of first serrations (6) may be angled ranging between 2°-5° with respect to the axis (A-A). In an embodiment, the steering wheel is mounted at a home position which may be considered as an ideal condition in which the position of the steering wheel corresponds to the straight-ahead position of the vehicle wheels to track the vehicle in a straight direction. A plurality of second serrations (22) is defined on the outer surface and located next to the first threaded portion (4) of the first shaft (2). In an embodiment, a length of the plurality of second serrations (22) on the first shaft (2) is smaller than the threaded portion (4). Further, a second threaded portion (24) is defined on the outer surface of the first shaft (2). In an embodiment, the second threaded portion (24) is defined with a diameter larger than the diameter of the first threaded portion (4), The second threaded portion (24) is configured to receive at least one locking nut (18) movable along a longitudinal direction of the first shaft (2). In an embodiment, the diameter of the plurality of second serrations (22) is equal to the first threaded portion (4) and however this cannot be construed as a limitation and the diameter may be more than that of the first threaded portion (4). In an embodiment, the first shaft (2) may be hollow and however this cannot be construed as a limitation and the first shaft (2) may also be configured as a solid shaft depending on a strength requirement of the steering shaft assembly (100). In an embodiment, the first shaft (2) and the second shaft (8) may be manufactured of steel, stainless steel and its alloys, forged steel and its equivalents which are suitable to withstand loads experienced by the first and second shafts (2, 8).
Referring to fig. 4, the second shaft (8) comprises a shank portion (7). A locking portion (10) is defined at one end of the shank portion (7). The locking portion (10) is configured as a hollow cylindrical structure to receive the first threaded portion (4). The locking portion (10) is defined with internal threads (12) that are complementary to the plurality of external threads of the first

threaded portion (4) to engage with the first threaded portion (4). The locking portion (10) is defined with an internal diameter matching with the diameter of the first threaded portion (4) to couple the second shaft (8) with the first shaft (2). A first knurling (25) is defined on an end surface of the second shaft (8). The first knurling (25) comprises a frictional surface to offer resistance against radial movement of the second shaft (8).
Referring to fig. 5, the at least one bush (14) is rotatably mounted on the first shaft (2). The at least one bush (14) is defined with at least one mating surface (17) at an end surface of the at least one bush (14) to engage with the second shaft (8). The at least one bush (14) is defined with a plurality of internal serrations (16) complementary to the plurality of second serrations (22) for mounting the at least one bush (14) on the first shaft (2). The at least one bush (14) is configured to lock radial movement of the first shaft (2). Further, the mating surface (17) is defined with a second knurling (26) complementary to the first knurling (25) to engage the at least one bush (14) with the second shaft (8). The first knurling (25) and the second knurling (26) provide resistance against a rotational movement of the first shaft (2) relative to the second shaft (8). The at least one locking nut (18) is disposed in contact with the at least one bush (14). The at least one locking nut (18) comprises internal threads (12) which are screwed or torqued on to the second threaded portion (24) to mount the at least one locking nut (18) on the first shaft (2). The at least one locking nut (18) is rotatable towards and away from the at least one bush (14) along the axis (A-A). The at least one locking nut (18) is configured to apply axial load on the at least one bush (14) upon its rotation in a first direction to engage the at least one bush (14) with the second shaft (8). At this position, the at least one bush (14) locks the rotational movement of the first shaft (2) and the second shaft (8) due to a frictional contact between the first knurling (25) and the second knurling (26). The at least one locking nut (18) is actuated or rotated in a second direction to radially adjust a position of the first shaft (2) with respect to the second shaft (8). In an embodiment, the first direction is along an axis (A-A) defined in a longitudinal direction of the first shaft (2) and the second direction is defined opposite and away from to the first direction. In an embodiment, the second direction is defined along the axis (A-A) and corresponds to the movement of the at least one locking nut (18) away from the second shaft (8).

Referring back to fig. 1 in conjunction with fig. 2, a vehicle and a method of assembling the steering shaft assembly (100) in the vehicle is disclosed. The vehicle comprises a steering wheel (20) defined in a home position. The home position of the steering wheel (20) corresponds to a straight-ahead position of a wheels [not shown in Figures] of the vehicle. In other words, the vehicle wheels are in a straight position to propel the vehicle in a straight direction when the steering wheel (20) is at the home position. A steering unit (30) is connected to at least one of front and rear wheels of the vehicle. In an embodiment, the steering unit (30) may include a universal joint coupled to a steering gear box. The steering unit (30) may further comprise a steering mechanism having plurality of drag links, tie rods and knuckles (not shown in figs.) which are connected to at least one steering arm. In an embodiment, the steering arms are connected to the wheels and the actuation of the steering wheel (20) reciprocates the steering arms to turn the wheels of the vehicle in a left or a right direction with respect to the straight-ahead position. In an embodiment, various steering mechanisms such as rack and pinion mechanism, Ackerman steering mechanism or turntable steering mechanism etc. may be used to transmit the input of the steering wheel (20) to the wheels of the vehicle. A steering shaft assembly (100) is configured to couple the steering wheel (20) at one end and the steering unit (30) at another end. The steering shaft assembly (100) comprises a first shaft (2) and a second shaft (8) which are interlocked with each other. The first shaft (2) and the second shaft (8) are disposed within the steering column (9). The second shaft (8) is inserted from a bottom end of the steering column (9). The second shaft (8) includes the locking portion (10) which receives the first shaft (2). The first shaft (2) is inserted from a top end of the steering column (9) and is coupled with the second shaft (8). The at least one bush (14) and the at least one locking nut (18) along the axis (A-A) are mounted sequentially on the first shaft (2). The at least one bush (14) is positioned in frictional contact with the end surface of the second shaft (8) by means of the first knurling (25) and the second knurling (26). The at least one locking nut (18) is configured to apply axial load on the at least one bush (14) when actuated in the first direction to lock the rotational movement of the first shaft (2) relative to the second shaft (8). Alternatively, the at least one locking nut (18) releases the axial load from the at least one bush (14) when actuated in the second direction to allow the relative movement to radially adjust the first shaft (2) with respect to the second shaft (8) to orient the steering wheel (20) to the home position. In other words, the relative movement of the first shaft (2) and the second shaft (8) are locked upon actuation of the at least one locking nut (18) towards the second shaft (8) and the

relative movement of both the first and second shafts (2, 8) is allowed when the at least one locking nut (18) is actuated away from the second shaft (8).
The working operation of the steering shaft assembly (100) is now explained in conjunction with fig. 6 and fig. 7. The steering wheel (20) is connected to the one end of the first shaft (2) of the steering shaft assembly (100). In ideal condition, the steering shaft is positioned in a home position when mounted on the first shaft (2). At the home position, a horizontal axis of the steering wheel (20) coincides a central axis (C-C) (shown in fig. 7a) to keep the wheels of the vehicle in the straight-ahead position. However, in case of misalignment of the steering wheel (20), the horizontal axis shifts by an angle (α) above or below from the central axis (C-C) (shown in figs. 7b & 7c). For example, the misalignment of the steering wheel (20) is caused by improper alignment of the plurality of first serrations (6) with an internal serrations (16) defined on a mounting portion (21) of the steering wheel (20). To position the steering wheel (20) back to the home position, the at least one locking nut (18) is initially actuated in the second direction to remove the axial load from the at least one bush (14). At this position, the axial load is removed from the at least one bush (14) and therefore the first shaft (2) may be radially adjusted with respect to the second shaft (8). After actuation of the at least one locking nut (18), the steering wheel (20) is actuated or rotated in required direction i.e., in a clockwise or an anti-clock wise direction to align the horizontal axis of the steering wheel (20) with the centre axis (A-A). Thus, the steering wheel (20) is oriented to the home position which matches with the straight-ahead position of the wheels of the vehicle to track the vehicle in the straight direction. After positioning the steering wheel (20) at the home position, the at least one locking nut (18) is actuated in the first direction to lock the radial movement of the first shaft (2) with respect to the second shaft (8). In this condition, the steering wheel (20) is actuated along with the first shaft (2) and the second shaft (8) of the steering shaft assembly (100) to steer the vehicle in a desired direction.
In an embodiment, the at least one locking nut (18) is located outside the steering column (9) and is accessible to orient the position of the steering wheel (20) to the home position by actuating the at least one locking nut (18).

In an embodiment, the steering shaft assembly (100) can be mounted in existing steering columns without making any alterations to the position of an ignition switch or other auxiliary components of the steering system within a cabin of the vehicle.
In an embodiment, the steering wheel (20) may be easily adjusted in a home position at the central axis (A-A) by actuation of the at least one locking nut (18) using external tools like spanner, wrench without requiring any complex tools.
In an embodiment, the alignment of the steering wheel (20) in the straight-ahead position may be done without removing the steering wheel (20). Advantageously this saves a lot of time and effort to orient the steering wheel (20) in the home position which also proves to be economical.
The steering shaft assembly (100) of the present disclosure is simple and easy to operate with lesser number of moving parts and components which in turn reduces the cost of manufacture.
The steering shaft assembly (100) of the present disclosure compensates the misalignment of the steering due to backlashes and clearance between the first serrations (6) and the serrations of the mounting portion (21) which may occur during installation of the steering wheel (20).
It is to be understood that a person of ordinary skill in the art may develop a structure of similar configuration without deviating from the scope of the present disclosure. Such modifications and variations may be made without departing from the scope of the present invention. Therefore, it is intended that the present disclosure covers such modifications and variations provided they come within the ambit of the appended claims and their equivalents. Further, various embodiments of the present disclosure can be combined or used in combination with each other without departing from the scope of the disclosure to provide the steering shaft assembly 100 with improved functionality.
Equivalents:
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is

appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations.
In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within

the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
REFERENCE NUMERALS:

Steering shaft Assembly 100
First shaft 2
Threaded portion 4
Body 5
A plurality of first serrations 6
Shank portion 7
Second shaft 8
Steering column 9
Locking portion 10
Internal threads 12
At least one bush 14
A plurality of internal serrations 16
At least one locking nut 18
Steering wheel 20
Mounting portion 21
A plurality of second serrations 22
Second threaded portion 24

First knurling 25
Second knurling 26
Steering unit 30

WE CLAIM:
1. A steering shaft assembly (100) for a vehicle, the steering shaft assembly (100) comprises:
a first shaft (2) defined with a first threaded portion (4) at one end and a plurality of first serrations (6) at an other end opposite to the one end, wherein the plurality of first serrations (6) are configured to receive a portion of a steering wheel (20);
a second shaft (8) defined with a locking portion (10) at one end configured to receive the first threaded portion (4), wherein the locking portion (10) is defined with an internal threads (12) that engage with the first threaded portion (4) to couple the second shaft (8) with the first shaft (2);
at least one bush (14) mounted on the first shaft (2), the at least one bush (14) is defined with at least one mating surface (17) to engage with the second shaft (8);
at least one locking nut (18) disposed in contact with the at least one bush (14), the at least one locking nut (18) is configured to apply axial load on the at least one bush (14) in a first direction to engage the at least one bush (14) with the second shaft (8);
wherein the first shaft (2) is radially adjusted with respect to the second
shaft (8) upon actuation of the at least one locking nut (18) in a second direction to
selectively orient the steering wheel (20).
2. The steering shaft assembly (100) as claimed in claim 1, wherein the plurality of first
serrations (6) are configured to receive a mounting portion (21) of the steering wheel (20)
to rotatably mount the steering wheel (20) on the first shaft (2).
3. The steering shaft assembly (100) as claimed in claim 1, wherein the first shaft (2) is defined with a plurality of second serrations (22) on a circumference of the first shaft (2) and a second threaded portion (24) is defined adjacent to the plurality of second serrations (22) to receive the at least one locking nut (18).
4. The steering shaft assembly (100) as claimed in claim 1, wherein the at least one bush is defined with a plurality of internal serrations (16) to engage with the plurality of second serrations (22).

5. The steering shaft assembly (100) as claimed in claim 1, wherein the second shaft (8) is
defined with a first knurling (25) on an end surface of the locking portion (10) to engage
with the mating surface (17) defined on the at least one bush (14).
6. The steering shaft assembly (100) as claimed in claim 1, wherein the mating surface (17) is defined with a second knurling (26) complementary to the first knurling (25) to engage the at least one bush (14) with the second shaft (8).
7. The steering shaft assembly (100) as claimed in claim 1, wherein the first direction is along an axis (A-A) defined in a longitudinal direction of the first shaft and the second direction is defined opposite and away from to the first direction.
8. The steering shaft assembly (100) as claimed in claim 1, wherein the plurality of first serrations (6) on the first shaft (2) are angled ranging between 2-5° with respect to the axis (A-A).
9. A vehicle comprising:
a steering wheel (20) defined in a home position;
a steering unit (30) connected to at least one of front and rear wheels of the vehicle;
a steering shaft assembly (100) configured to couple the steering wheel (20) at one
end and the steering unit (30) at another end, the steering shaft assembly (100) comprising:
a first shaft (2) defined with a threaded portion (4) at one end and a plurality of first serrations (6) at an other end opposite to the one end, wherein the plurality of first serrations (6) are configured to receive a portion of the steering wheel (20);
a second shaft (8) defined with a locking portion (10) at one end configured to receive the threaded portion (4), wherein the locking portion (10) is defined with internal threads (12) that engage with the threaded portion (4) to couple the second shaft (8) with the first shaft (2);

at least one bush (14) mounted on the first shaft (2), the at least one bush (14) is defined with at least one mating surface (17) to engage with the second shaft (8);
at least one locking nut (18) disposed in contact with the at least one bush (14), the at least one locking nut (18) is configured to apply axial load on the at least one bush (14) in a first direction to engage the at least one bush (14) with the second shaft (8);
wherein the first shaft (2) is radially adjusted with respect to the second shaft (8) upon actuation of the at least one locking nut (18) in a second direction to selectively orient the steering wheel (20) to the home position.
10. The vehicle as claimed in claim 9, wherein the home position of the steering wheel (20) corresponds to a movement of the vehicle in a straight direction by the steering unit (30) upon actuation of the steering wheel (20).