FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
"WHEEL STOPPERS" 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
INVENTORS
Ajay Dhuri, Milind Bhatambarekar
All 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 describes the invention
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Field of Invention:
The present invention relates to wheel stoppers for limiting the maximum steered wheel angle.
Background:
Vehicles generally include a stop mechanism that limits the steer angle of the wheels to prevent contact between the rotatable wheel and other structural elements. The stop mechanism generally comprises mating elements on the vehicle's axle and steering knuckle assembly that contact each other at a certain maximum steering angle and thereby limit further pivoting movement of the steering knuckle relative to the axle.
The greater the steering angle, the tighter the radius of turn that is achievable. Generally, to increase maneuverability, a greater steering angle is preferable. A given vehicle type will have a range of maximum steer angles within which the angle can be adjustably set according to the actual conditions within which the vehicle operates in the field.
Fig. 1 describes an apparatus of a vehicle of a prior art, the apparatus comprising a wheel stopper 130 rigidly fastened to a chassis frame 135. When the maximum steering position is reached, as designed for maximum maneuverability of the vehicle, the pitman arm 110 mates with said wheel stopper 130 thereby stopping the further rotation of the wheel. Another wheel stopper 130 is also fastened at the other side of the chassis frame 135 to restrict the maneuvering of the wheel in the other direction.
In the vehicles of the prior art as shown in Fig. 2 and Fig. 3, wheel stopper 130 restricts the movement of the Pitman arm 110 at a particular position when maximum steering angle is reached. The Pitman arm 110 is a part of the Steering assembly of a vehicle while wheel stoppers 130 are fastened on the chassis frame 135. It is often found that the wheel stopper 130 do not properly align with the Pitman arm 110 resting face. There is thus risk of slipping of the Pitman arm 110 across the wheel stopper 130 bolt.
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There is therefore a need for proper positioning of wheel stopper that do not stop the Pitman arm but some other face of an axle.
Object of the Invention:
An object of the of the present invention is to prevent the contact between the rotatable wheel and structural elements of a vehicle.
Another object of the present invention is to stop the stub axle, having a large flat surface, from rotating beyond a particular angle as permissible for maximum maneuverability in a vehicle.
Yet another object of the present invention is to make use of large surface area of stub axle to stop wheel.
Further object of the present invention is to provide an adjustable wheel stopper. Still further object of the present invention is to provide a plurality of predefined locations where the wheel stopper can be fastened. Still further object of the present invention is to provide a robust wheel stopper.
Although the present invention has been described with reference to certain embodiments as hereinafter, the invention is not limited to the embodiments. Various other embodiments of the invention will be apparent to a person skilled in the art or follow from routine experimentation.
Description:
Fig. 4 shows the wheel stopper 230 mounted on lower wishbone 235, mating with stub axle 220 which is steered by tie rod 215. The pitman arm 210 rotation is carried out by the steering gear box 200. The central link 225 connects the pitman arm 210 to the idler arm (not shown in figure) which in turn steers the other wheel. Figure 6 shows the wheel stopper 230, comprising: an adjustable bolt 231, a lock nut 232, a weld nut 233, and a mounting bolt 234.
One embodiment of the present invention discloses the novel arrangement of the wheel stopper 230 on the lower wishbone 235 instead of the vehicle chasis frame, for effective mating of wheel stopper 230 and stub axle 220.
Another embodiment of the present invention discloses the mating elements as wheel stopper 230 and stub axle 220 instead of pitman arm 210 and wheel stopper 230
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owing to the misalignments of stopper 230 and the pitman arm 210 resting face, thereby resulting in slipping of the mating parts.
Yet another embodiment of the present invention discloses the plurality of predefined locations of mounting of the wheel stopper 230 on the lower wishbone 235. The stub axle 220, having large flat surface, allows the plurality of the wheel stopper 230 positions on the lower wishbone 235 instead of a specific location.
Yet another embodiment of the present invention discloses the adjustability of length of the wheel stopper 230 comprising of adjustable bolt 231 as shown in Fig.6 thereby providing means for adjusting the stopper 230 for effective mating as desired.
It is reiterated that the present invention is not limited to the above embodiments. Various other embodiments of the invention will be apparent to a person skilled in the art or follow from routine experimentation.
Dated this 18th day of June, 2007
To
The Controller of Patents,
Patent Office, Mumbai
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