FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIOANL SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
Steering Arm Mounting System and Method of Mounting thereof
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
INVENTORS
Mr. Hari Srinivas Babu Aggarapu and Mr.Swapnil R. Salunkhe,
both Indian Nationals
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 describes the invention

Field of invention:
This invention relates generally to a Steering arm and more particularly to a sheet metal type steering arm mounting system and method of mounting thereof.
Background of the invention
Conventionally, Steering arms for automobiles have been manufactured either by casting or forging and are integral part of steering knuckles. Steering arm integrated with steering knuckle manufactured in casting or forging are basically designed to provide the required strength & stiffness to withstand various loads encountered by steering arm during various steering maneuverings. However, the cost of such casted or forged steering arms/knuckles are quite high for the following reasons:
1) Requirement of subsequent machining operation to close tolerance limits.
2) Integral steering arm requires complex mould to be made thereby contributing to additional cost.
3) Increased weight of the knuckle conversely requires the other mating steering/suspension parts to be made heavier to withstand the combined loads of steering knuckle integrated with steering arm.
In the past, various attempts have been made to reduce the cost of the steering knuckles by fabricating them from sheet metal with integrated steering arm, US 4,674,760 & US 3,865,394 teaches a unitary sheet metal knuckle with integral steering arm. Also attempts have been made to fabricate steering knuckles in sheet metal with separate sheet metal steering arm mounted on it In order to overcome the said drawbacks, this steering arm is devised.


Objects of Invention:
The main object of this invention is to provide a steering arm mounting system which is capable of mounting independently on to a steering knuckle.
Yet another object of this invention is to provide Steering arm mounting system and method of mounting thereof that requires fewer machining operations compared to casted /forged assemblies.
Yet another object of this invention is to provide Steering arm mounting system and method of mounting thereof which is capable of providing desired shapes to enhance the rigidity of the entire steering system.
Yet another object of this invention is to provide Steering arm mounting system and method of mounting thereof which is simple in construction and cost effective.
Yet another object of this invention is to provide Steering arm mounting system and method of mounting thereof which is easy to install & maintain.
Brief Description of Invention:
This invention is related to Steering arm mounting system and method of mounting thereof, which can be easily accommodated on different vehicles. Steering arm mounting system in accordance with this invention basically comprises of an independent sheet metal element that can be mounted to the knuckle through the same mounting as used for suspension strut and also that can be designed to any desirable shape & dimension without touching the other peripheral parts in case of increased steering loads based on increment in FAW of


the vehicle for reasons depicted by market requirements. The sheet metal steering arm is generally L-shaped structure with uniform thickness through-out. However, for the purpose of mitigating stresses at the bend plane, the steering arm is provided with uniform bend radius sufficient to minimize the stress raisers.
The independent sheet metal steering arm comprises of a sheet metal with uniform thickness with a bend plan to accommodate the steering tie rod ball joints at the other end. The mounting of the steering arm is through two holes that are common with the suspension strut mounting passing through the forged knuckle. Based on the rigidity requirements of the steering system, the steering arm is given a suitable shape so as to avoid fouling with other vehicle parts apart from giving the required rigidity.
This invention aims at providing a design of sheet metal steering arm that is capable of mounting independently to the steering knuckle and can be used with various steering knuckles without affecting the design of the steering knuckle. Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.
Description of the preferred embodiments of the invention:
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.l is front View of the assembly Knuckle with mounting arrangement of Independent steering arm.


FIG. 2 is an exploded perspective view of a first embodiment of the subject
invention.
FIG.3 is Sheet metal steering arm used in this invention
Now referring to figs. 1 to 3, the steering knuckle assembly (2) is a forged element, generally with extended flange (2a) at the top for assembly of the strut (3) and extended arm at the bottom (2b) for the assembly of lower suspension ball joint (5). The suspension ball joint (5) is connected to the lower control arm (4). The lower control arm is secured to the vehicle structure through bushes (9).
The steering arm (1) is fabricated by a sheet metal structure. The sheet metal steering arm has a provision of tapered hole (10) to accommodate the ball joint from the steering rack & pinion tie-rod. The steering rod end ball joint is retained in position by means of a nut. The steering tie rod is pushed in & out to allow articulation of the wheel mounted thereto when the steering wheel is rotated clockwise & counter clockwise. A nut is secured to the steering tie rod ball joint end which is extended through the steering arm having a provision to accommodate the same. This ball joint end is a part of the steering rack & pinion tie rod end. The sheet metal steering arm (1) is placed over the suspension strut mounting and bolts (7) are used for assembling the steering arm (1) & suspension strut (3) together to the forged knuckle.
The sequence of assembly of the steering arm is as illustrated in exploded view as shown in fig. 2.
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.