FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
A brake disc assembly for automobiles
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.Sundar Kumar P, Mr.Shah Ashesh A, Abhyankar Umesh L and Deokar
Amol S
AH 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 particularly describes the invention and the manner in
which it is to be performed

FIELD OF INVENTION:
The present invention generally relates to vehicle disc brake assembly and more particularly to a twin flange hub mounted straight ring type brake disc assembly for automobiles.
BACKGROUND OF THE INVENTION
A braking system is the most important system in an automobile as it helps to keep the vehicle under control and keep the driver safe. The vehicles are equipped with brake system for slowing or stopping the movement of vehicle in a controlled manner. The service brakes are generally provided in vehicle to stop it with in a specified distance with limited pedal effort. The brakes are also one of the regulatory requirements of the vehicle. Different types of brakes are installed in automobiles of all kinds, trucks, trains, motorcycles, etc. A disc brake is the best brake we have found so far.
A typical disc brake assembly includes a rotor which is secured to a wheel of the vehicle for rotation therewith. The rotor includes a pair of opposed friction plates which are engaged by portions of a caliper assembly. The conventional disc brake system consists of a step type brake disc which is either solid or ventilated type. It consists of brake faces opposite to each other and is functionally pressed against each other by friction pads for braking phenomenon of the vehicle.
The step type brake disc includes a mounting face which is mounted on the hub of vehicle. The mounting face is provided with the centre bore. The mounting holes and auxiliary holes are provided in the conventional disc brake to remove the brake disc from the hub of vehicle without any difficulty. In convention brake systems, the casting of step ventilated brake disc is complicated and also more number of operations is required for complete machining, which increases the overall weight and the cost of manufacturing of the brake disc. In addition, the conventional brake disc includes a complicated arrangement with counter sunk hole and counter sunk screws to ensure mating of the brake disc with a hub flange.

The wheel mounting threaded studs are provided on the hub through, which the disc is guided. More over, the weight of these step discs are always on higher side. Hence there is a need to provide a novel disc brake assembly to overcome the above mentioned drawbacks.
OBJECT OF THE INVENTION
The main objective of the present invention is to obviate above mentioned
drawbacks.
Another object of the present invention is to provide a twin flange hub mounted
straight ring type brake disc for motor vehicles.
Yet another object of the present invention is to simplify the casting and
machining processes required to manufacture the brake disc for automobiles.
Yet another object of the present invention is to provide a hub with two flanges to
mount the brake disc and the wheel on separate flanges.
Yet another object of the present invention is to reduce the additional holes,
tapping and screws required for mounting the brake disc assembly.
Yet another object is to reduce the weight and the cost of manufacturing of the
brake disc.
SUMMARY OF THE INVENTION
The various embodiments of the present invention provide a brake disc assembly for an automobile. The brake disc assembly comprises a hub with two flanges, a first flange and a second flange. A brake disc and a wheel rim mounted on said first flange and second flange respectively by fastening means. The brake disc is a straight ring type structure with a plurality of mounting bosses provided on the inner circumference of the disc brake. According to another embodiment, because of serviceability requirement said first and second flanges are provided with openings for the accessibility which forms plurality of radial extensions on the flanges. The plurality of radial extensions includes tapping holes/holes. The brake disc and wheel rim is mounted on said first flange and second flange radial extensions respectively by fastening means. The radial extensions of said first and

second flanges are not overlapping to facilitate the accessibility to the fastening means of brake disc. The edges of adjacent radial extensions are formed like curved profile to create a vacation in said second flange for accessing said fastening means of said brake disc.
According to one embodiment of present invention, a caliper with a stub axle is mounted on the brake disc and the shaft of said stub axle is passes through the hollow portion of said hub during assembly and locked with a lock nut therein. A hole is provided on said second flange; and a dowel pin provided in said hole of radial extension of said second flange for assisting in locating said wheel rim during mounting of wheel rim with said second flange.
Accordingly, the brake disc mounting is provided on three tapped bosses on the brake disc without any additional requirement of counter sunk holes, tapping and screws. The disc brake assembly reduces the casting and the machining process required to manufacture the brake disc for motor vehicles and hence reduces the weight and the cost of manufacturing of the brake disc. The hub with two flanges supports the separate mounting for wheel rim and brake disc. In this case, removing of brake disc is also possible without removing hub.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an exploded view of the disc brake assembly, according to one embodiment of the present invention.
FIG. 2 shows an assembled view of the disc brake assembly, according to one embodiment of the present invention.
FIG. 3 shows a perspective view of the brake disc, according to one embodiment of the present invention.

FIG. 4 shows a perspective view of the hub with two flanges, according to one embodiment of the present invention.
FIG. 5 shows a side view of the hub with two flanges, according to one embodiment of the present invention.
FIG. 6 shows a front view of the wheel rim, according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The various embodiments of the present invention provide a brake disc assembly for an automobile. The brake disc assembly comprises a hub with two flanges, a first flange and a second flange. A brake disc and a wheel rim are mounted on said first flange and second flange respectively by fastening means. The first flange and second flange includes a plurality of tapping holes/holes. The brake disc is a straight ring type structure with a plurality of mounting bosses provided on the inner circumference of the disc brake. According to one embodiment, because of serviceability requirement said first and second flanges are provided with a plurality of radial extensions. The plurality of radial extensions includes tapping holes/holes. The brake disc and wheel rim is mounted on said first flange and second flange radial extensions respectively by fastening means. The radial extensions of said first and second flanges are not overlapping to facilitate the accessibility to the fastening means of brake disc. The edges of adjacent radial extensions are formed like curved profile to create a vacation in said second flange for accessing said fastening means of said brake disc.
The brake disc mounting is provided on three tapped bosses on the brake disc without any additional requirement of counter sunk holes, tapping and screws. The disc brake assembly reduces the casting and the machining process required to manufacture the brake disc for motor vehicles and hence reduces the weight and the cost of manufacturing of the brake disc. The hub with twin flanges

supports the separate mounting for wheel rim and brake disc. In this case, removing of brake disc is also possible without removing hub.
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. 1 shows art exploded view of the disc brake assembly, according to one embodiment of the present invention. The disc brake assembly includes a straight ring type brake disc 10, a hub 20 with a first flange 21 and a second flange 22, a caliper 40, and a stub axle 60. The brake disc 10 includes three tapping holes 11, 12 and 13. A tapping is provided on the brake disc 10 to assemble the first flange
21 of the hub 20 using screws 30. The second flange 22 of the hub 20 includes three tapping holes 26, 27 and 28 (Ref FIG. 4). The second flange 22 of the hub 20 also includes a tapping hole 29 provided to insert a dowel pin 31, which is used for locating the wheel rim 70. The caliper 40 is to be mounted on the stub axle 60. The bearing is placed inside hub 20 and the hub 20 passes through the shaft of the stub axle 60 and a lock nut 50 is assembled at the end of the stub axle 60 to secure the hub 20. For serviceability requirement said first flange 21 and second flange
22 are provided with a plurality of radial extensions 21' and 22'. The plurality of radial extensions 21' and 22' includes tapping holes/holes. The brake disc and wheel rim is mounted on said first flange and second flange radial extensions respectively by using screws 30. The radial extensions 21' and 22' of said first and second flanges 21 and 22 are not overlapping to facilitate the accessibility screws 30 of the brake disc 10. The edges of adjacent radial extensions 21' and 22' are formed like curved profile 80 to create a vacation in said second flange 22 for accessing said fastening means of said brake disc 10. The curved profiles 80 for the first flange and second flange are machined so as to avoid removal of hub 20 while removing brake rotor 10. With respect to the above arrangement in the second flange 22, a corresponding three mounting holes 71, 72 and 73 are

provided on the wheel rim 70 with one guiding hole 74 to accommodate the dowel pin 31.
FIG. 2 shows an assembled view of the disc brake assembly, according to one embodiment of the present invention. Referring to FIG. 2, shows a front brake system including a straight ring type brake disc 10 mounted on the hub 20. The caliper 40 with stub axle 60 is mounted on the brake disc 10. The caliper 40 consisting of friction pads is mounted on the stub axle 60 and brake disc is located between these pads. The straight brake disc opposite faces comes in contact with the friction pads of caliper 40 during braking phenomenon. The brake disc 10 is assembled on first flange 21 of the hub 20 with screws 30 at three places 23, 24 and 25. A corresponding tapping hole 11, 12 and 13 are provided on the bosses of brake disc 10. The second flange 22 of the hub 20 is utilized for three points mounting of wheel rim 70 for which tapping holes 26, 27 and 28 are provided on the second flange 22 of the hub 20. As shown in FIG. 2, the radial extensions 21' and 22' of said first and second flanges 21 and 22 are not overlapping to facilitate the accessibility of screws 30 of the brake disc 10. The edges of adjacent radial extensions 21' and 22' are formed like curved profile 80 to create a vacation in said second flange 22 for accessing said fastening means of said brake disc 10. The bearing is placed inside the hub 20 and it goes through the shaft of the stub axle 60. The lock nut 50 is assembled at the end of the stub axle 60 to secure the hub 20. The second flange 22 of the twin flange hub 20 also includes a tapping provided for dowel pin 31 which is used for locating the wheel rim 70. The brake disc mounting is provided on three tapped bosses with out any additional requirement of counter sunk hole on brake disc.
FIG. 3 shows a perspective view of the brake disc, according to one embodiment of the present invention. The brake disc 10 is ring shaped and includes three mounting points 11, 12 and 13 on the inner circumference of the brake disc 10. The brake disc assembly includes a hub with two flanges (Ref FIG. 3). The brake disc 10 is mounted on the first flange of the hub. The brake disc mounting is

provided on three tapped holes 11, 12 and 13 with out any additional requirement of counter sunk hole on rotor.
FIG. 4 shows a perspective view of the twin flange hub, according to one embodiment of the present invention. With respect to FIG. 4, the hub 20 includes two flanges, a first flange 21 and a second flange 22.
The first flange 21 and second flange 22 are provided with a plurality of radial extensions 21' and 22'. The plurality of radial extensions 21' and 22' includes tapping holes/holes. The holes 23, 24 and 25 are provided on the radial extension 21' of said first flange 21. Similarly a curved profile 80 with tapping holes 26, 27 and 28 is provided on the radial extension 22' of said second flange 22. The curved profile creates opening for accessing the fastening means of the brake disc 10. The openings in first flange serve the purpose of removing the brake disc without removing the hub. This is achieved by rotating the disc 10 after removing fastenings. The holes 23, 24 and 25 are provided on the first flange 21 to assemble the hub 20 with the corresponding tapping holes on the brake disc 10. The tapping holes 26, 27 and 28 on the second flange 22 are provided to assemble the hub 20 corresponding holes in the wheel rim 70. The second flange 22 of the hub 10 also includes a tapping hole 29 provided for dowel pin 31 which is used for locating the wheel rim 70. The radial extensions 21' and 22' of said first and second flanges 21 and 22 are not overlapping to facilitate the accessibility screws 30 of the brake disc 10. The edges of adjacent radial extensions 21' and 22' are formed like curved profile 80 to create a vacation in said second flange 22 for accessing said fastening means of said brake disc 10. The curved profiles 80 for the first flange and second flange are machined so as to avoid removal of hub 20 while removing brake rotor 10. FIG. 5 shows a side view of the hub with two flanges, according to one embodiment of the present invention. FIG.6 shows a front view of the wheel rim 70. The wheel rim 70 includes three tapping holes 71, 72 and 73 with one guiding hole 74 to accommodate the dowel pin 31.

ADVANTAGES
• The twin flange hub mounted straight ring type brake disc assembly
simplifies the casting and reduces the number of machining process
required to manufacture the brake disc for motor vehicles.
• The assembly according to present invention assists in mounting the brake disc without requiring additional holes, tapping and screws.
• The assembly according to present invention reduces the weight and the cost of manufacturing of the brake discs.
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 brake disc assembly for an automobile, comprising:
a hub with two flanges, a first flange and a second flange;
a brake disc and a wheel rim mounted on said first flange and second flange respectively by fastening means.
1. The brake disc assembly according to claim 1, wherein said brake disc is a straight ring type structure with a plurality of mounting bosses provided on the inner circumference of the disc brake.
3. The brake disc assembly according to claim 1, wherein said flanges includes plurality of tapping holes/holes.
4. The brake disc assembly according to claim 1, wherein said first flange with plurality of tapping holes/holes is mounted on the corresponding tapped bosses provided on the brake disc using mounting screws.
5. The brake disc assembly according to claim \, wherein the second flange with plurality of tapping holes is mounted on the corresponding tapping holes provided on said wheel rim using mounting screws.
6. A brake disc assembly for an automobile, comprising:
a hub with two flanges, a first flange and a second flange with plurality of
radial extensions; a brake disc and a wheel rim mounted on said first flange and second flange radial extensions respectively by fastening means.
7. The brake disc assembly according to claim 6, wherein said brake disc is a
straight ring type structure with a plurality of mounting bosses provided on the
inner circumference of the disc brake.

8. The brake disc assembly according to claim 6, wherein the radial extensions of
said first and second flanges are not overlapping to facilitate the accessibility
to the fastening means of brake disc.
9. The brake disc assembly according to claim 6, wherein the edges of adjacent radial extensions are formed like curved profile to create a vacation in said flange for accessing the fastening means of said brake disc.
10. The brake disc assembly according to claim 6, wherein said plurality of radial extensions includes tapping holes/holes.
11. The brake disc assembly according to either claim 1 or claim 6, wherein said hub is a hollow cylindrical structure with a bearing located inside.
12. The brake disc assembly according to either claim 1 or claim 6, wherein a caliper with a stub axle is mounted on the brake disc and the shaft of said stub axle is passes through the hollow portion of said hub during assembly and locked with a lock nut therein.
13. The brake disc assembly according to either claim 1 or claim 6, wherein a hole
provided on said second flange; and a dowel pin provided in said hole of
radial extension of said second flange for assisting in locating said wheel rim
during mounting of wheel rim with said second flange.