FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
Symmetric knuckle assembly with detachable steering arm
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTOR
Sandip Kulkarni, Pranav Phatak, Rahul Sarode
Indian national
of TATA MOTORS LIMITED an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner
in which it is to be performed.

FIELD OF INVENTION
This invention relates to a Symmetric knuckle with detachable steering arm for an independent suspension system of a vehicle and more particularly to a symmetric steering knuckle with brake caliper attached on it.
BACKGROUND OF INVENTION
Conventionally knuckle is manufactured by forging or casting and the components include the strut, spindle, caliper mountings and steering arm and allows the front wheel to pivot. Steering knuckle provides an attachment point for the tie rod to the wheel where it pivots. The steering knuckle also provides an attachment point for the upper and lower ball joints in conventional suspension system where as in Macpherson strut systems; the steering knuckle anchors the lower end of the strut and the lower ball joint. The spindle of a rear wheel drive vehicle is supported and attached by the steering knuckle. With a front wheel drive vehicle, the front hub and bearing assembly is attached to the steering knuckle. Disc brake systems also use the steering knuckle as a mount for the brake caliper. A knuckle assembly of this type may utilize a dozen or more parts which must be assembled before installation of the knuckle assembly in the vehicle for which it was designed. Conventional assembly consists of a lower control arm with integrated ball joint, brake caliper, strut, wheel hub bearing assembly, steering tie rod and ABS sensor connected to knuckle.
As per prior art, different steering knuckles are used at Left Hand and Right Hand locations due to specific positions of steering assembly & brake caliper assembly.
In the existing proposals, as knuckle assembly of this type consist a dozen or more parts, there is always a separate knuckle for left & right side of the vehicle. More specifically, brake caliper mounts on the knuckle from front of the vehicle where as steering tie rod mounts from the rear side. Hence to satisfy the both mounting

requirements, steering & brake caliper, separate knuckle needs to be designed for a vehicle, which increases design time and subsequently cost.
OBJECT OF THE INVENTION
The main object of the invention is to obviate the above mentioned drawbacks.
Another object of the invention is having the single steering knuckle for Left Hand & Right Hand side.
Yet another object of the invention is to reduce the complexity on the assembly line as well as minimizes the initial development cost and time of the vehicle.
SUMMARY OF THE INVENTION
The embodiments herein provide a steering knuckle for vehicle suspension system. The steering knuckle comprises a first steering arm, second steering arm and third steering arm extending radially outwards from said steering knuckle. A detachable steering arm is connected to said second or third steering arm for connecting with tie rod outer ball joint. Atleast two mounting locations are provided on said first, second and third steering arms for selectively mounting a caliper and said detachable steering arm for manufacturing left hand steering knuckle assembly or right hand steering knuckle assembly as per requirement. A strut mounting arm provided in said first steering arm for mounting with strut assembly and a lower ball joint for mounting with a lower control arm.
According to present invention the first, second and third radial extension arms are symmetrical to each other. One end of said detachable steering arm includes atleast two hole for mounting with said atleast two holes in said second or third steering arm and other end having atleast one hole for connecting with tie rod outer ball joint. Atleast two mounting holes are provided on strut mounting arm for mounting with

strut assembly and atleast one mounting hole provided in lower ball joint arrangement for mounting with lower control arm.
The brake caliper is mounted on said first steering arm and second steering arm and the detachable steering arm is mounted on said third steering arm in right hand steering knuckle assembly. The brake caliper is mounted on said first steering arm and third steering arm and the detachable steering arm is mounted on said second steering arm in left hand steering knuckle assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more folly understood by reference to the following detailed description of a preferred embodiment of the present invention when read in conjunction with the accompanying drawing, in which:
FIG. A is an elevated perspective view of steering knuckle complete which shows steering knuckle with unique mounting holes arrangement.
FIG. B is a view of detachable steering arm which serve the purpose of connecting tie rod with steering knuckle.
FIG. C shows exploded view of steering knuckle and brake caliper.
Fig. D shows exploded view of steering knuckle along with brake caliper and detachable steering arm.
Fig. E shows the symmetrical knuckle used on both Left Hand and Right Hand side along with brake caliper and steering arm.

DETAILED DESCRIPTION OF THE INVENTION
For a vehicle suspension system, symmetric knuckle having detachable steering arm offers the flexibility of using unique steering knuckle which can be used on either sides of the vehicle i.e. in Left Hand side and Right Hand Side. Use of detachable steering arm gives the advantage of using alternative material for weight reduction purpose.
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same.
Fig. A represents steering knuckle 14 consists of 3 arms namely 8, 9, 10 extending radial outwards from the knuckle along with strut mounting arm 13 and lower ball joint attachment arm 11. Unique mounting holes 3,4, 5, 6, 7 are provided on radially extended arms whereas mounting holes 1 and 2 are provided for strut mount and mounting hole 27 is provided for lower control arm mounting using lower ball joint attachment.
Fig. B shows detachable steering arm 25. Steering arm 25 consists of two mounting holes 20 and 21 for attaching the arm to steering knuckle. Hole 22 is provided to attach tie rod outer ball joint with the steering arm.
Fig. C shows the exploded view of knuckle and brake caliper assembly along with caliper mounting bolts for Right Hand side. Brake caliper 17 is mounted on the knuckle 14 using arm 8 and 9. Caliper 17 is bolted to the knuckle 14 through 3 and 15 using bolt 18 as well as through 4 and 16 using bolt 19.
Fig. D shows a complete Right Hand side knuckle assembly in exploded view. Here steering arm 25 is bolted to knuckle 14. As shown in the figure hole 20 is aligned to

hole 7 and bolted by bolt 23 while hole 21 is aligned with hole 5 and bolted by bolt 24. Hole 22 on steering arm 25 is used to attach steering tie rod ball joint.
Fig. E shows views for complete steering knuckle Right Hand 26A & Left Hand 26B assemblies. In steering knuckle Right Hand assembly 26A, brake caliper 17A is bolted to the knuckle 14 through hole 3 and hole 15A using bolt 18 as well as through hole 4 and hole 16A using bolt 19 where as steering arm 25A is bolted to knuckle 14 by aligning the holes 20A and 21A with holes 7 and 5 respectively. Bolts 23 and 24 are used to fasten the steering knuckle 14 with the steering arm 25A. Here hole 3 and hole 4 of steering knuckle 14 are used for assembling brake caliper 17A with it. Hole 15A and hole 16A of brake caliper 17A are used to fasten it with knuckle 14. More specifically hole 3 is aligned with hole 15A and hole 4 is aligned with hole 16A to fasten brake caliper 17A with steering knucklel4. Moreover steering arm 25A is bolted to the steering knuckle 14 through bolts 23 and 24. Here hole 20A and 21A is aligned with the hole 7 and 5 respectively. In steering knuckle Right Hand assembly 26A, hole 6 remains unused. This hole 6 is given on steering knuckle 14 for steering arm Left Hand 25B mounting in steering knuckle Left Hand assembly 26B. This steering arm 25B is a mirror image of steering arm 25 A. Single steering arm can be possible in case of particular steering outer ball joint position. As far as steering knuckle Left Hand assembly 26B is concern, the same steering knuckle 14 is used. Here hole 3 and hole 5 of steering knuckle 14 are used for brake caliper 17B mounting where as hole 4 and hole 6 of the same steering knuckle 14 are used for steering arm 25B mounting. In this case, hole 7 remains unused which is used in steering knuckle assembly 26A for steering arm 25A mounting.
The foregoing description is a specific embodiment of the present invention. This invention comprises of symmetrical steering knuckle with detachable steering arm. As per prior art, different steering knuckles are used at Right Hand & Left Hand locations due to specific positions of steering assembly & brake caliper assembly. In

present invention attempt has been done to make the unique steering knuckle which can be used on either sides of the vehicle. Five mounting locations are provided on the knuckle which can be used selectively for attachment of caliper & steering arm as per Right Hand & Left Hand assembly requirement. Here the major advantage of unique or single steering knuckle is reduction in development cost for knuckle assembly. It helps in reducing the complexity at assembly area as well as tack time for the said assembly. Further to this, such a unique design helps in reducing the weight of the component.
Advantages:
• Instant application, completely removes the development of two separate components
• It results in achievement of major reduction in development with the unique steering knuckle design.
• This application facilitates to reduce the complexity at assembly area. It also helps in reducing the tack time for the assembly.
• Moreover the invention helps in reducing the weight and consequently cost of the component.
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.

We Claim
1. A steering knuckle for vehicle suspension system, comprising;
a first steering arm, second steering arm and third steering arm extending radially outwards from said steering knuckle;
a detachable steering arm connected to said second or third steering arm for connecting with tie rod outer ball joint;
at least two mounting locations provided on said first, second and third steering arms for selectively mounting a caliper and said detachable steering arm for left hand steering knuckle assembly or right hand steering knuckle assembly as per requirement;
a strut mounting arm 13 provided in said first steering arm for mounting with strut assembly;
a lower ball joint for mounting with a lower control arm;
2. The steering knuckle according to claim I, wherein said first, second and third radial extension arms are symmetrical to each other.
3. The steering knuckle according to claim 1, wherein one end of said detachable steering arm having at least two holes for mounting with said at least two holes in said second or third steering arm and other end having at least one hole for connecting with tie rod outer ball joint.
4. The steering knuckle according to claim 1, wherein at least two mounting holes are provided on strut mounting arm for mounting with strut assembly and at least one mounting hole provided in lower ball joint arrangement for mounting with lower control arm.

5. The steering knuckle according to claim 1, wherein in right hand steering knuckle assembly said brake caliper is mounted on said first steering arm and second steering arm and said detachable steering arm is mounted on said third steering arm.
6. The steering knuckle according to claim 1, wherein one hole of at least two holes in said second steering arm is unused in right hand steering assembly.
7. The steering knuckle according to claim 1, wherein in left hand steering knuckle assembly said brake caliper is mounted on said first steering arm and third steering arm and said detachable steering arm is mounted on said second steering arm.
8. The steering knuckle according to claim 1, wherein one hole of at least two holes in said third steering arm is unused in left hand steering assembly.
9. The steering knuckle as herein described with reference to accompanying
drawings.