FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION Cross member for vehicle
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
Ajit S Dubai
Ganesh Kumar N
both 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

Field of Invention
This invention relates to the ladder type of frames used for multi utility vehicles. More specifically, this invention relates to an improved structure for closed channel structural member, such as cross member, for use in such a vehicle body & frame assembly to increase strength & rigidity. Ladder types of frames are used in vehicles in which body is mounted on frame assembly & the frame is mounted on resilient suspension system.
Background of invention
A multi utility rear wheel driven vehicle chassis frame includes a dedicated assembly cross member for supporting engine gear box assembly. Cross member further provides increased torsional and lateral stiffness to the chassis frame against the loads commonly encountered by a vehicle during operation. This cross member acts as medium, gear box vibrations to cab, through cab mounting brackets attached to the frame. Hence care to be taken while designing gear box mounting cross member such that, it isolates objectionable vibration from originating from gear box.
The structures of the known body & frame assemblies can be divided in to two general categories, namely, separate and unitized. In a typical separate body and frame assembly, the structural components of body portion and frame portion of the vehicle are separate and independent from one another. When assembled, the frame portion of the assembly is resiliency supported upon the vehicle wheels by the suspension system and serves as platform upon which the body portion of the assembly and other components of the vehicle can be mounted. Separate body and frame assemblies of this general type are found in most older vehicles ,but remains in common use today for large multi utility vehicle's, sport utility vehicles, vans.


Typical ladder type frame construction includes two assembly side long members supported by more than two cross members based on requirement of strength, application, weight consideration & safety consideration.
Traditionally, the gear box mounted cross members of Multi Utility vehicle chassis frame assemblies have been formed with either open channel or uniform tubular cross section. However use of open & tubular section cross member in chassis frame assemblies has been found to be undesirable for several reasons, like lack of strength, rigidity, and also from NVH view. To address this, it has been proposed to form one or more components & design a closed channel structural member's with hat cross section at the joinery location. This cross sectional shape is advantageous because it provides strength and rigidity to vehicle body and frame assembly.
Summary of invention
This invention results to an improved closed channel structural member, such as cross member for use in frame assembly to increase strength and rigidity used for mounting of drive shaft centre bearing. This cross member reduces the point mobility of frame to maximum extent when compared with Tubular section cross member. The cross member section is gradually increased towards the end where it is connected to long-member by plug welding process.
Assembly consists of a central tubular member supported by hat shaped bracket at both ends. The central tubular member is bolted to the side brackets and said brackets welded to the long members. Brackets having a cross section shape of an inverted open channel cross section, where the end area of cross section is higher than the cross sectional area where the bracket connected to the tubular cross member.


Description of drawing:
Fig . 1 shows the top view of assembly frame for a Multi utility vehicle in which the invented cross member is used.
Fig .2 shows the isometric view of assembly cross member.
Detailed description of 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 shows the complete assembly frame sketch used for a multi utility vehicle .The frame assembly has many cross member assemblies serving different purposes. In this detailed description we will be briefing on parts that are necessary for complete understanding of this invention. The illustrated vehicle frame assembly 11 is a ladder type frame assembly which includes a pair of long members 12 & 13 which are generally parallel to each other through out length .
Cross members (75, 15a 15g) attached between the long members thus gives a
ladder type appearance. The cross members (15,15a 15g) extended
perpendicular to the long members are spaced apart from one another and secured to the long member 12 and 13 by any conventional means such as by welding, riveting or bolting. For a typical MUV frame all the cross members are welded to long members 12 & 13.


The cross members (15,15a 15g) provides desirable lateral and torsional
rigidity to the frame. A plurality of body mounting brackets 14 are secured to the long members by welding. The cab is mounted on the brackets and fastened by bolts, rubber bushes and nuts. The cab mounting brackets 14 form a medium to transfer the vibrations from chassis to the cab. Our invention cross member 15d dampens those vibrations in the chassis 11 itself and improves ride pleasure to the passenger inside the cab. The detailed sketch of invention assembly cross member 15d is shown in Fig 2.
Fig.-2 shows the isometric view of assembly centre bearing cross member 15d. Assembly consists of a central tubular member (rectangular) (2) supported by hat shaped bracket (3) at both ends. The central tubular member (2) is bolted (5) to the side brackets (3) and said brackets welded to the long members. Edges of the brackets formed as flanges (4) locate on the long member. Brackets having a cross section shape of an inverted open channel cross section, where the end area of cross section is higher than the cross sectional area where the bracket connected to the tubular cross member. Gear box supporting bracket is provided on the central tubular member (2).