[001] The embodiments herein generally relate to steering systems in vehicles and more particularly, to a steering arm for an assisted steering system (considered to be single acting hydraulic cylinder power steering system, power steering system and the like) of a vehicle, which has optimized design that restricts/reduces the wear and tear of kingpin splines (external splines of kingpin) during operation of the assisted steering system thereby increasing the life of the kingpin and operating efficiency of the assisted steering system.
BACKGROUND
[002] Generally, a steering system in a vehicle controls directional change in the movement of the vehicle and maintain in a position as per the decision of the driver driving the vehicle. The steering system of the vehicle converts the rotary movement of a steering wheel into angular movement (turn) of the wheels of the vehicle. A steering arm in the steering system of the vehicle is used to rotate (turns) corresponding kingpin which in turn angularly moves corresponding wheels of the vehicle through corresponding stub axles during operation of the steering system. A conventional hydraulic power steering system in vehicles such as tractors and other similar vehicles, includes a power steering single acting hydraulic cylinder, steering arm S (as shown in fig. 1 and fig. 2), kingpin K (as shown in fig. 1) and other standard components as present in standard hydraulic power steering system. The plurality of internal splines Si (as shown in fig. 1 and fig. 2) of the steering arm S is engaged with corresponding plurality of external splines Ke (as shown in fig. 1) of the kingpin K. However, there might be a free play between the kingpin K and the steering arm S during the operation of the single acting hydraulic cylinder such that the

steering arm S is not securely locked to the kingpin K due to geometrical inaccuracies (manufacturing and machining variations) of the kingpin K and steering arm S. To control the geometrical inaccuracies of the kingpin K and steering arm S, the steering arm S is provided with a through horizontal threaded opening and through vertical slit Sg (as shown in fig. 1 and fig. 2) which intersects the through horizontal threaded opening, where through horizontal threaded opening receives a bolt Sb (as shown in fig. 1) therethrough, and the bolt Sb is adjusted with a nut Sn (as shown in fig. 1) which is on the other side of the bolt Sb therein to tighten the steering arm S with the kingpin K thereby closing the clearance (minimal gap) between the kingpin K and the steering arm S to secure the steering arm S with the kingpin K, and the through vertical slit Sg allows the adjustment of the bolt Sb which tightens the steering arm S with kingpin K. However, the adjustment of the bolt Sb which tightens the steering arm S with king pin K leads to high stress concentration on corresponding plurality of external splines Ke of the kingpin K due to bolt pretension, and non-uniformly distributes the applied turning torque on the plurality of external splines Ke of the kingpin K which in turn increases the wear and tear of the external splines Ke of the kingpin K during operation of the power steering single acting hydraulic cylinder of the hydraulic power steering system. Further, the external splines Ke of the kingpin K which are in front of the bolt B is subjected to high stress (due to bolt pretension) which in turn increases the wear and tear of the external splines Ke (in front of the bolt Sb) of the kingpin K during operation of the power steering single acting hydraulic cylinder of the hydraulic power steering system. Furthermore, the steering arm S and the kingpin K are less durable and has less strength.
[003] Therefore, there exists a need for a steering arm for an assisted steering system of a vehicle, which has optimized design that restricts/reduces the wear and tear of kingpin splines (external splines of

kingpin) during operation of the assisted steering system thereby increasing the life of the kingpin and operating efficiency of the assisted steering system. Further, there exists a need for a steering arm and a kingpin for an assisted steering system of a vehicle, which obviates the aforementioned drawbacks.
OBJECTS
[004] The principal object of an embodiment of this invention is to provide a steering arm for an assisted steering system (considered to be single acting hydraulic cylinder power steering system, power steering system and the like) of a vehicle, which has optimized design that restricts/reduces the wear and tear of kingpin splines (external splines of kingpin) during operation of the assisted steering system thereby increasing the life of the kingpin and operating efficiency of the steering system.
[005] Another object of an embodiment of this invention is to provide a steering arm and a kingpin for an assisted steering system (considered to be single acting hydraulic cylinder power steering system, power steering system and the like) of a vehicle, which is durable and has better strength (high strength).
[006] Another object of an embodiment of this invention is to provide a steering arm steering arm for an assisted steering system (considered to be single acting hydraulic cylinder power steering system, power steering system and the like) of a vehicle, which defines a blind slit that facilitates uniform contact pressure between corresponding portion (bottom portion) of corresponding plurality of external splines of a kingpin and corresponding portion (bottom portion) of corresponding plurality of internal splines of the steering arm to uniformly distribute the applied turning torque on corresponding portion (bottom portion) of corresponding

plurality of external splines of the kingpin during operation of power steering single acting hydraulic cylinder therein to restrict (reduce) the wear and tear of bottom portion of corresponding plurality of external splines of the kingpin thereby increasing the life of the kingpin and operating efficiency of the assisted steering system.
[007] Another object of an embodiment of this invention is to provide a steering arm for an assisted steering system (considered to be single acting hydraulic cylinder power steering system, power steering system and the like) of a vehicle, which has optimized design that enables easier operation of the steering mechanism.
[008] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF DRAWINGS
[009] The embodiments of the invention are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0010] Fig. 1 depicts a perspective view of a conventional steering arm, a conventional kingpin, a bolt and a nut in assembled condition;

[0011] Fig. 2 depicts a perspective view of the conventional steering arm;
[0012] Fig. 3 depicts a perspective view of a steering arm for an assisted steering system (considered to be single acting hydraulic cylinder power steering system) of a vehicle, according to an embodiment of the invention as disclosed herein;
[0013] Fig. 4 depicts a partial perspective view of the steering arm, according to an embodiment of the invention as disclosed herein;
[0014] Fig. 5 depicts a top view of the steering arm, according to an embodiment of the invention as disclosed herein;
[0015] Fig. 6 depicts a perspective view of a kingpin in the assisted steering system, according to an embodiment of the invention as disclosed herein;
[0016] Fig. 7 depicts a perspective view of the kingpin, the steering arm, a fastener (bolt) and a threaded element (nut) in assembled condition, according to an embodiment of the invention as disclosed herein; and
[0017] Fig. 8 depicts a perspective view of the assisted steering system (single acting hydraulic cylinder power steering system), according to an embodiment of the invention as disclosed herein.

DETAILED DESCRIPTION
[0018] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0019] The embodiments herein achieve a steering arm for an assisted steering system (considered to be single acting hydraulic cylinder power steering system, power steering system and the like) of a vehicle, which has optimized design that restricts/reduces the wear and tear of kingpin splines (external splines of kingpin) during operation of the assisted steering system thereby increasing the life of the kingpin and operating efficiency of the assisted steering system. Referring now to the drawings, and more particularly to FIGS. 3 through 8, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0020] Fig. 8 depicts a perspective view of an assisted steering system of a vehicle, according to an embodiment of the invention as disclosed herein. Fig. 3 depicts a perspective view of a steering arm 10 for the assisted steering system of a vehicle, according to an embodiment of the invention as disclosed herein. In an embodiment, the assisted steering system includes a plurality of steering arms 10 (as shown in fig. 3 to fig. 5, fig. 7 and fig. 8, only one of which is shown in fig. 8), at least one kingpin

20 (as shown in fig. 6 to fig. 8, only one of which is shown in fig. 8), a power steering single acting hydraulic cylinder 100H (as shown in fig. 8), a plurality of stub axles (not shown), a plurality of wheels (not shown) and may include other standard components/mechanisms as present in a standard power assisted steering system (hydraulic power steering system). In an embodiment, the steering arm 10 defines a plurality of internal splines 101 (also called as internal teeth, as shown in fig. 3 to fig. 5), a portion ION (as shown in fig. 3 to fig. 5), a fastener receiving portion 10F (as shown in fig. 3 and fig. 4) and a blind slit 10G (as shown in fig. 3 to fig. 5). For the purpose of this description and ease of understanding, the steering arm 10 of the assisted steering system (power assisted steering system) is explained herein below with reference to be provided in a single acting hydraulic cylinder power steering system of a tractor. However, it is also within the scope of the invention to implement/practice the steering arm 10 in an electro-hydraulic power steering system, electric power steering system, any other power assisted steering system or any other steering system of an off-road vehicle, a constructional vehicle, agricultural vehicle and/or any other type of vehicle without otherwise deterring the intended function of the steering arm 10 as can be deduced from the description and corresponding drawings.
[0021] The plurality of internal splines 101 (also called as internal teeth) of the steering arm 10 is adapted to be provided in engagement with corresponding plurality of external splines 20E1 (as shown in fig. 7) of the kingpin 20. The plurality of internal splines 101 (also called as internal teeth) of the steering arm 10 is provided to an inner portion of the steering arm 10. In an embodiment, the portion ION of the steering arm 10 is adapted to be provided in non-engagement with corresponding plurality of external splines 20E2 of the kingpin 20 in which the portion ION is not in contact with corresponding plurality of external splines 20E2 (as shown in

fig. 7) of the kingpin 20, therein to restrict the wear and tear of
corresponding plurality of external splines 20E2 of the kingpin 20 during
the operation of the power steering single acting cylinder 100H of the
assisted power steering system thereby increasing the life of the kingpin 20
5 and operating efficiency of the assisted steering system. The portion 10N
of the steering arm 10 extends between corresponding internal splines 10I (10Ia and 10Ib, as shown in fig. 3 to fig. 5) in a direction away from corresponding internal splines 10I (10Ia and 10Ib) along an axial direction 10X (as shown in fig. 4) of the steering arm 10. The portion 10N of the
10 steering arm 10 is at least a through vertical opening (through vertical
groove). The fastener receiving portion 10F of the steering arm 10 is adapted to receive a fastener B (considered to be bolt, as shown in fig. 7) therethrough, and the fastener B could be adjusted with a threaded element N (considered to be nut N as shown in fig. 7) which is on the other side of
15 the fastener B therein to facilitate lockable engagement of plurality of
internal splines 10I of the steering arm 10 with corresponding plurality of external splines 20E1 of the kingpin 20 thereby securing the steering arm 10 with the kingpin 20, where the fastener receiving portion 10F is a through horizontal threaded opening. In an embodiment, the blind slit 10G
20 of the steering arm 10 is adapted to be provided at a predetermined position
in which the bottom end of the blind slit 10G intersects with the fastener receiving portion 10F at a predetermined position, and the top end of the blind slit 10G intersects with the portion 10N at a predetermined position, where the blind slit 10G is adapted to facilitate uniform distribution of
25 contact pressure between corresponding portion (bottom portion) of
corresponding plurality of internal splines 10I of the steering arm 10 and corresponding portion (bottom portion) of corresponding plurality of external splines 20E1 of the kingpin 20 therein to restrict stress concentration on corresponding portion (bottom portion) of corresponding
9/16

plurality of external splines 20E1 of the kingpin 20 on fastener B
pretension (tightening of the fastener B), and the blind slit 10G enables
uniform distribution of applied turning torque on corresponding portion
(bottom portion) of corresponding plurality of external splines 20E1 of the
5 kingpin 20 during operation of the power steering single acting cylinder
100H of the assisted power steering system to restrict (reduce) the wear and tear of corresponding portion (bottom portion) of corresponding plurality of external splines 20E1 of the kingpin 20 thereby increasing the life of the kingpin 20 and operating efficiency of the assisted steering
10 system. In an embodiment, the number of internal splines 10I (internal
teeth) of the steering arm 10 is 15. It is also within the scope of the invention to provide the steering arm 10 with any number of internal splines (internal teeth). In an embodiment, the steering arm 10 is made up of 42CrMon4 material. It is also within the scope of the invention to
15 provide the steering arm 10 to be made of any other metallic material, non-
metallic material or any other type of material.
[0022] Fig. 6 depicts a perspective view of a kingpin 20 in the assisted steering system, according to an embodiment of the invention as disclosed herein. The kingpin 20 defines a plurality of external splines
20 (20E1 and 20E2, also called as external teeth) provided along the
circumference of the outer portion of the kingpin 20. The plurality of external splines (20E1 and 20E2) of the kingpin 20 includes a plurality of external splines 20E1 and a plurality of another external splines 20E2. The plurality of external splines (20E1 and 20E2) of the kingpin 20 is lockably
25 engaged with corresponding plurality of internal splines 10I of the steering
arm 10. The plurality of another external splines 20E2 of the kingpin 20 is in front of the fastener B (considered to be bolt), and is not in contact with the portion 10N of the steering arm 10 therein to restrict (reduce) the wear and tear of corresponding plurality of external splines 20E2 of the kingpin
10/16

20 during the operation of the power steering single acting hydraulic
cylinder 100H of the assisted power steering system thereby increasing the
life of the kingpin 20 and operating efficiency of the assisted steering
system. In an embodiment, the number of external splines (20E1 and 20E2,
5 external teeth) of the kingpin 20 is 21. It is also within the scope of the
invention to provide the kingpin 20 with any number of external splines
(external teeth). In an embodiment, the kingpin 20 is made up of
42CrMon4 material. It is also within the scope of the invention to provide
the kingpin 20 to be made of any other metallic material, non-metallic
10 material or any other type of material. The kingpin 20 has circular cross-
section. It is also within the scope of the invention to provide the kingpin 20 with any other cross-section.
[0023] Therefore, a steering arm 10 which restricts (reduces) the
wear and tear of the external splines (20E1 and 20E2) of a kingpin 20 in an
15 assisted steering system (considered to be single acting hydraulic cylinder
power steering system) is provided for a vehicle.
[0024] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various
20 applications such specific embodiments without departing from the generic
concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of
25 limitation. Therefore, while the embodiments herein have been described
in terms of embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

We claim,

A steering arm 10 for an assisted steering system of a vehicle, said steering arm 10 defining,
a plurality of internal splines 101 adapted to be provided in engagement with corresponding plurality of external splines 20E1 of a kingpin 20;
a portion ION adapted to be provided in non-engagement with corresponding plurality of another external splines 20E2 of the kingpin 20; and
a blind slit 10G adapted to be provided at a predetermined position.
The steering arm 10 as claimed in claim 1, wherein said portion ION extends between corresponding said internal splines 101 (101a and 101b) in a direction away from corresponding said internal splines 101 (101a and 101b) along an axial direction 10X of said steering arm 10,
wherein
said portion ION is provided in non-engagement with corresponding plurality of another external splines 20E2 of the kingpin 20 in which said portion ION is not in contact with corresponding plurality of another external splines 20E2 of the kingpin 20, therein to restrict the wear and tear of corresponding plurality of another external splines 20E2 of the kingpin 20 during the operation of the assisted power steering system, where said portion ION of said steering arm 10 is at least a through vertical opening (through vertical groove).
3. The steering arm 10 as claimed in claim 2 defines a fastener receiving portion 10F adapted to receive a fastener B (considered to be bolt) therethrough, and the fastener B could be adjusted with a threaded

element N (considered to be nut N) which is on the other side of the fastener B therein to facilitate lockable engagement of said plurality of internal splines 101 of said steering arm 10 with corresponding plurality of external splines 20E1 of the kingpin 20 thereby securing said steering arm 10 with the kingpin 20, where said fastener receiving portion 10F is a through horizontal threaded opening.
The steering arm 10 as claimed in claim 3, wherein the bottom end of said blind slit 10G intersects with said fastener receiving portion 1 OF at a predetermined position, and the top end of said blind slit 10G intersects with said portion ION at a predetermined position, where said blind slit 10G is adapted to facilitate uniform distribution of contact pressure between corresponding portion (bottom portion) of corresponding said plurality of internal splines 101 of said steering arm 10 and corresponding portion (bottom portion) of corresponding plurality of external splines 20E1 of the kingpin 20 therein to restrict stress concentration on corresponding portion (bottom portion) of corresponding plurality of external splines 20E1 of the kingpin 20 on fastener B pretension (tightening of the fastener B), and said blind slit 10G enables uniform distribution of applied turning torque on corresponding portion (bottom portion) of corresponding plurality of external splines 20E1 of the kingpin 20 during operation of the assisted power steering system to restrict (reduce) the wear and tear of corresponding portion (bottom portion) of corresponding plurality of external splines 20E1 of the kingpin 20 during the operation of the assisted power steering system.

The steering arm 10 as claimed in claim 1, wherein the assisted steering system is at least a hydraulic power steering system (considered to be a single acting hydraulic cylinder power steering system).
A steering arm 10 for an assisted steering system of a vehicle, said steering arm 10 defining,
a plurality of internal splines 101 adapted to be provided in engagement with corresponding plurality of external splines 20E1 of a kingpin 20;
a portion ION adapted to be provided in non-engagement with corresponding plurality of external splines 20E2 of the kingpin 20 in which said portion ION is not in contact with corresponding plurality of external splines 20E2 of the kingpin 20, thereby restricting the wear and tear of corresponding plurality of external splines 20E2 of the kingpin 20 during the operation of the assisted power steering system; and
a blind slit 10G adapted to be provided at a predetermined position, wherein the bottom end of said blind slit 10G intersects with said fastener receiving portion 10F at a predetermined position, and the top end of said blind slit 10G intersects with said portion ION at a predetermined position, where said blind slit 10G is adapted to facilitate uniform distribution of contact pressure between corresponding portion of corresponding said plurality of internal splines 101 of said steering arm 10 and corresponding portion of corresponding plurality of external splines 20E1 of the kingpin 20 therein to restrict stress concentration on corresponding portion of corresponding plurality of external splines 20E1 of the kingpin 20 on fastener B pretension, and said blind slit 10G enables uniform distribution of applied turning torque on corresponding portion of corresponding plurality of external splines 20E1 of the kingpin 20 during operation of the assisted power steering system

thereby restricting the wear and tear of corresponding portion of corresponding plurality of external splines 20E2 of the kingpin 20.
The steering arm 10 as claimed in claim 6, wherein said portion ION extends between corresponding said internal splines 101 (101a and 101b) in a direction away from corresponding said internal splines 101 (101a and 101b) along an axial direction 10X of said steering arm 10, where said portion ION of said steering arm 10 is at least a through vertical opening (through vertical groove).