FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
AND
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10; Rule 13)
TITLE OF THE INVENTION
“VARIABLE FRAME BRACKET ASSEMBLY FOR A TWIST-BEAM TYPE SUSPENSION SYSTEM TO VARY A ROLL STIFFNESS”
APPLICANT(S) TATA MOTORS PASSENGER VEHICLES LIMITED
Floor 3, 4, Plot-18, Nanavati Mahalaya,
Mudhana Shetty Marg, BSE,
Fort, Mumbai - 400001
Maharashtra, India
Nationality Indian.
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
[0001] The present invention relates to vehicle suspension, and more specifically related to a frame bracket assembly for a twist-beam type suspension system of a vehicle.
BACKGROUND OF THE INVENTION
[0002] In recent years, torsion beam suspensions, which have a small number of parts, a relatively simple structure, and excellent space efficiency, have been widely adopted for suspension devices for vehicles such as four-wheeled vehicles, mainly for small displacement vehicles. The typical trailing beam suspension comprises a hanger bracket suspended from a trailer frame rail. A twist beam or arm is pivotably connected at one end to the hanger bracket to enable the trailing beam to pivot about a horizontal axis. The twist beam comprises an inverted, U-shaped beam for bending loads, coupled with a separate solid torsion rod with different material and characteristics, and extending through the open central portion of the beam, for resist torsional loads.
[0003] In some of the cases the separate rod is being provided to control torsional loads is specially fabricated of a high strength steel. Its ends are attached separately from bracket with trailing arms. The contemporary design having single roll stiffness value requires lots of modification leading to huge cost impact in case of change in roll stiffness is required. The structure of contemporary designs is the fully fabricated welded structure having stamped / Hydro formed child parts including stab bar which provides fixed roll stiffness and does not have provision for tuning the roll stiffness according to the vehicle or project need. Therefore, in the conventional designs, all the parts are welded together, which provides the fix output in terms of roll stiffness. Which is causing the limitations during vehicle ride and handling tuning and also while catering the different roll stiffness requirements of other platform vehicles through comonisation.

[0004] Hence there remains a need for an improvised design of the stiffness brackets that provides liberty to tune the roll stiffness for twist-beam type suspension system as per the requirement without much cost impact and provide a solution to above mentioned problem.
OBJECT OF THE INVENTION
[0005] The principal object of the embodiments herein is to provide a frame bracket assembly for a twist-beam type suspension system of a vehicle. Separate insulated stiffener frame bracket is provided with bolted arrangement to change the roll stiffness of the twist beam as per the requirement.
[0006] Another object of the embodiments herein is to provide a twist-beam type suspension system for tuning in roll stiffness easily as per need. Slots are provided on trailing arm along its length to change the position of stiffener bracket in order to modify and achieve the required roll stiffness.
[0007] Yet another object of the embodiments is to provide a non-metallic sheet (for example, rubber insulation sheet) on the stiffener frame bracket to avoid metallic interaction and noise between cross beam of the trailing arm and stiffener frame bracket. The required stiffness can be tuned by simply inserting the stiffener frame bracket with rubber cladding for noise avoidance at right position and fixed through bolted arrangement.
SUMMARY OF THE INVENTION
[0008] In one aspect the object is satisfied by providing a frame bracket assembly for a twist-beam type suspension system of a vehicle. The frame bracket assembly includes a non-metallic sheet provided on an outer surface of the frame bracket assembly, a metal sheet provided on an inner surface of the frame bracket assembly, and a bolts arrangement provided on the inner surface of

the frame bracket assembly to vary a roll stiffness of the twist beam. The bolts arrangement comprises at least four bolts bolted to a beam section of the twist beam.
[0009] In an embodiment, a thickness of the non-metallic sheet is 2 millimeter.
[0010] In an embodiment, wherein a thickness of the metal sheet is 4 millimeter.
[0011] In an embodiment, the frame bracket assembly is a U-shaped open profile comprising a drawn or stamped member having a single torsional stiffness value.
[0012] In another aspect the object is satisfied by providing a twist-beam type suspension system of a vehicle to vary a roll stiffness. The twist-beam type suspension system includes a pair of frame bracket assemblies each of which comprises a bolts arrangement to vary a roll stiffness of the twist beam, and a trailing arm including a plurality of slots provided along a length of the trailing arm. Each of the frame bracket assemblies operably coupled to opposite ends of the trailing arm through the plurality of slots to change a position of each of the frame bracket assembly in order to modify and achieve the required roll stiffness.
[0013] In an embodiment, a position of each of the frame bracket assemblies is moved towards an outward direction of the vehicle.
[0014] In an embodiment, the movement of the frame bracket assemblies towards the outward direction of the vehicle increases a center section length of trailing arm to reduce the roll stiffness.
[0015] In an embodiment, a position of each of the frame bracket assemblies is moved towards an inward direction of the vehicle.

[0016] In an embodiment, the movement of the frame bracket assemblies towards the inward direction of the vehicle increases a variable section length of trailing arm to increase the roll stiffness.
[0017] In an embodiment, each of the frame bracket assemblies includes a non-metallic sheet provided on an outer surface of the frame bracket assembly, a metal sheet provided on an inner surface of the frame bracket assembly, and the bolts arrangement provided on the inner surface of the frame bracket assembly to vary a roll stiffness of the twist beam.
[0018] These and other aspects 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 preferred 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 scope thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF THE DRAWING(S)
[0019] The proposed a frame bracket assembly for a twist-beam type suspension system 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:
[0020] Figures 1a and 1b illustrates perspective views of a frame bracket assembly for a twist-beam type suspension system, according to embodiments as disclosed herein; and

[0021] Figures 2a to 2c illustrates perspective views of the twist-beam type suspension system of a vehicle to vary a roll stiffness, according to embodiments as disclosed herein.
[0022] It may be noted that to the extent possible, like reference numerals have been used to represent like elements in the drawing. Further, those of ordinary skill in the art will appreciate that elements in the drawing are illustrated for simplicity and may not have been necessarily drawn to scale. For example, the dimension of some of the elements in the drawing may be exaggerated relative to other elements to help to improve the understanding of aspects of the invention. Furthermore, the one or more elements may have been represented in the drawing by conventional symbols, and the drawings may show only those specific details that are pertinent to the understanding the embodiments of the invention so as not to obscure the drawing with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
DETAILED DESCRIPTION OF INVENTION
[0023] 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. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The term “or” as used herein, refers to a non-exclusive or, unless otherwise indicated. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0024] Referring now to the drawings, and more particularly to FIGS. 1 through 2, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[0025] FIGS. 1a and 1b illustrates perspective views of a frame bracket assembly (1) for a twist-beam type suspension system, according to embodiments as disclosed herein. The frame bracket assembly (1) includes a non-metallic sheet (2), a metal sheet (3), and a bolts arrangement (4). The frame bracket assembly (1) is a U-shaped open profile including a drawn or stamped member having a single torsional stiffness value. For example, the center beam which is being made by using stamping process and has open loop cross section.
[0026] The non-metallic sheet (2) is provided on an outer surface of the frame bracket assembly (1). An example of the non-metallic sheet (2) can include, but is not limited to, rubber insulation sheet. In an embodiment, a thickness of the non-metallic sheet (2) is 2 millimeter. The non-metallic sheet (2) is provided on the stiffener frame bracket to avoid metallic interaction between a cross beam and the stiffener frame bracket (1) and subsequent possibility any noise issue. Further the metal sheet (3) is provided on an inner surface of the frame bracket assembly (1). In an embodiment, a thickness of the metal sheet (3) is 4 millimeter.
[0027] The bolts arrangement (4) is provided on the inner surface of the frame bracket assembly (1) to vary a roll stiffness of a twist beam (7) (also referred as cross beam). The bolts arrangement (4) includes at least four bolts bolted to a beam section of the twist beam (7).
[0028] Unlike the conventional frame bracket the proposed frame bracket assembly (1) provides liberty to tune the roll stiffness as per the requirement without much cost impact. The required stiffness can be tuned by simply inserting the stiffener

frame bracket (1) with rubber or non-metallic element cladding for noise avoidance at right position and fixed through the bolted arrangement (1).
[0029] FIGS. 2a-2c illustrates perspective views of the twist-beam type suspension system of a vehicle to vary a roll stiffness, according to embodiments as disclosed herein. The twist-beam type suspension includes a pair of frame bracket assemblies (1a, 1b) mounted on a trailing arm (5).
[0030] Each of the frame bracket assemblies (1a, 1b) includes a non-metallic sheet
(2) provided on an outer surface of the frame bracket assembly (1), a metal sheet
(3) provided on an inner surface of the frame bracket assembly (1), and a bolts arrangement (4) provided on the inner surface of the frame bracket assembly (1) to vary a roll stiffness of the twist beam (7). The bolts arrangement (4) includes at least four bolts bolted to a beam section of the twist beam (7).
[0031] The trailing arm (5) includes a plurality of slots (6) provided along a length of the trailing arm (5). Each of the frame bracket assemblies (1a, 1b) operably coupled to opposite ends of the trailing arm (5) through the plurality of slots (6) to change a position of each of the frame bracket assembly (1) in order to modify and achieve the required roll stiffness. Two separate insulated stiffener frame bracket assemblies (1a, 1b) with four number of weld nuts (4) to put inside the beam section as per requirement. Similarly the holes or slots (6) are provided on the cross beam at both side along the length of a cross section to position the stiffener frame bracket (1). Each of the stiffener frame bracket (1a, 1b) is bolted on the twist beam (7) and positioned as per the requirement. In an embodiment, each of the frame bracket assemblies (1a, 1b) are connected to the twist beam (7) through the slots (6) using flange bolts for locking the position. Each of the frame bracket assemblies (1a, 1b) are adjustable (8) along the twist beam (7) as per the requirement as shown in the FIG. 2c.

[0032] The non-metallic sheet (2) provided on the stiffener frame bracket (1) to avoid metallic interaction between the twist beam (7) and the frame bracket (1).
[0033] During the torsional loading cross beam section tends to resist the roll motion of the vehicle due to its sectional properties. The roll stiffness of the twist beam (7) depends on a center section length (10) and a variable section length (9) at the end of the twist beam (7) as shown in the FIG. 2c. The center section length (10) is generally contestant, while the variable section length (9) are varied as per the movement of the frame bracket assemblies (1a, 1b). In order to reduce the roll stiffness contribution, a position of each of the frame bracket assemblies (1a, 1b) is moved towards an outward direction of the vehicle. The movement of the frame bracket assemblies (1a, 1b) towards the outward direction of the vehicle increases the center section length (10) of trailing arm (5) to reduce the roll stiffness.
[0034] In order to increase the roll stiffness contribution, a position of each of the frame bracket assemblies (1a, 1b) is moved towards an inward direction of the vehicle. The movement of the frame bracket assemblies (1a, 1b) towards the inward direction of the vehicle increases the variable section length (9) of trailing arm (5) to increase the roll stiffness.
[0035] Therefore the proposed frame bracket assembly for the twist-beam type suspension system is used to enhance the performance of the vehicle by fine tuning in roll stiffness easily as per need. Need of different vehicles of roll stiffness can be achieved easily with minimum modifications enabling communication of welded structure in a vehicle platform catering different segment of the vehicles.
[0036] 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 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 limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described herein.
[0037] List to reference numerals:

Sr. No. Description
1, 1a, 1b frame bracket assembly
2 non-metallic sheet
3 metal sheet
4 bolts arrangement
5 trailing arm
6 slots
7 twist beam
8 adjustable
9 variable section length
10 center section length

We Claim:
1. A frame bracket assembly (1) for a twist-beam type suspension system of a
vehicle, wherein the frame bracket assembly (1) comprises:
a non-metallic sheet (2) provided on an outer surface of the frame bracket assembly (1);
a metal sheet (3) provided on an inner surface of the frame bracket assembly (1); and
a bolts arrangement (4) provided on the inner surface of the frame bracket assembly (1) to vary a roll stiffness of the twist beam (7), wherein the bolts arrangement (4) comprises at least four bolts bolted to a beam section of the twist beam (7).
2. The frame bracket assembly (1) as claimed in claim 1, wherein a thickness of the non-metallic sheet (2) is 2 millimeter.
3. The frame bracket assembly (1) as claimed in claim 1, wherein a thickness of the metal sheet (3) is 4 millimeter.
4. The frame bracket assembly (1) as claimed in claim 1, wherein the frame bracket assembly (1) is a U-shaped open profile comprising a drawn or stamped member having a single torsional stiffness value.
5. A twist-beam type suspension system of a vehicle to vary a roll stiffness,
wherein the twist-beam type suspension system comprises:
a pair of frame bracket assemblies (1a, 1b) each of which comprises a bolts arrangement (4) to vary a roll stiffness of the twist beam (7); and
a trailing arm (5) comprises a plurality of slots (6) provided along a length of the trailing arm (5), wherein each of the frame bracket assemblies (1a, 1b) operably coupled to opposite ends of the trailing arm (5) through the plurality of

slots (6) to change a position of each of the frame bracket assembly (1) in order to modify and achieve the required roll stiffness.
6. The twist-beam type suspension system as claimed in claim 5, wherein a position of each of the frame bracket assemblies (1a, 1b) is moved towards an outward direction of the vehicle.
7. The twist-beam type suspension system as claimed in claim 6, wherein the movement of the frame bracket assemblies (1a, 1b) towards the outward direction of the vehicle increases a center section length (10) of trailing arm (5) to reduce the roll stiffness.
8. The twist-beam type suspension system as claimed in claim 5, wherein a position of each of the frame bracket assemblies (1a, 1b) is moved towards an inward direction of the vehicle.
9. The twist-beam type suspension system as claimed in claim 8, wherein the movement of the frame bracket assemblies (1a, 1b) towards the inward direction of the vehicle increases a variable section length (9) of trailing arm (5) to increase the roll stiffness.
10. The twist-beam type suspension system as claimed in claim 5, wherein each of the frame bracket assemblies (1a, 1b) comprises
a non-metallic sheet (2) provided on an outer surface of the frame bracket assembly (1);
a metal sheet (3) provided on an inner surface of the frame bracket assembly (1); and
the bolts arrangement (4) provided on the inner surface of the frame bracket assembly (1) to vary a roll stiffness of the twist beam (7), wherein the bolts arrangement (4) comprises at least four bolts bolted to a beam section of the twist beam (7).

11. The twist-beam type suspension system as claimed in claim 10, wherein a thickness of the non-metallic sheet (2) is 2 millimeters.
12. The twist-beam type suspension system as claimed in claim 10, wherein a thickness of the metal sheet (3) is 4 millimeters.
13. The twist-beam type suspension system as claimed in claim 5, wherein each of the frame bracket assembly (1) is a U-shaped open profile comprising a drawn or stamped member having a single torsional stiffness value.