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 PROCESS FOR FORMING CUTOUT IN FLOOR PANEL FOR
VEHICLES
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
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 relates to a floor panel for vehicles and particularly to a process for manufacturing floor panel for new product variants in vehicles. More particularly to perforated sheet metal at floor panel to generate a cutout as per product design at suitable stage in vehicles.
BACKGROUND OF INVENTION
At present the product designers are designing new product variants in vehicles by modifying an existing product design of original model. The modification in the original model requires forming a cut-out in the original model. The option of producing cutout on finished car body, with conventional method (e.g. cutting with pneumatic saw) has following demerits. The time required to generate such cutout, will create cycle time bottleneck on metal finish line. The cutting process noise will not be within shop floor norms. The generated cutout will be shabby with wavy surface. It will be difficult to maintain dimensional accuracy. A highly skilled operator will be required to generate a cut out.
It is advisable to develop the new product variants in the original manufacturing line, in order to keep capital investment and conversion cost low. On the other hand, the introduction of new variants in the original manufacturing line will create following problems and these are required to be resolved, to maintain line efficiency as per original specifications. A Line shutdown is required to install new equipments in the manufacturing line. The cost of this production loss is huge and it will be charged on new product development cost. If the new equipments are exclusive for new variants, then they will not be fully utilized. Also these equipments require exclusive manpower which gets unutilized, when new variants are not produced during mixed

production system. If odd processes like plasma cutting, laser cutting are required to be installed, line uptime will get adversely affected. Costly equipments will have larger return on investment, for lower volume of variants. The new processes require additional space for new stations, in between the existing line, which may not be always available. If additional space is not available for sufficient number of stations, then cycle time bottlenecks will be formed. In totality, productivity of the original line will get adversely affected. Hence there is a need for innovative processes at the initial phase of new variant, so that productivity of manufacturing line will not get affected.
OBJECT OF THE INVENTION
The primary objective of the present invention is to provide a perforated sheet metal at rear floor panel in vehicles to retain its strength and principle locating points, which are necessary during car welding process.
Another objective of the present invention is to retain the strength of the vehicle frame during manufacturing process and generate the cutout only at the final stage of the panel manufacturing process.
Yet another object of the present invention is to develop the new product variants along with the original product in mixed production mode.
Yet another object of the present invention is to provide as low cost solution with minimum line modification and for fast introduction of variants.
SUMMARY OF THE INVENTION
The embodiments herein provide a process for forming cut-out in floor panel for vehicles. The process for forming cut-out comprising providing perforations on said

floor panel along said cutout path before the panel welding/during panel manufacturing process, Slitting said perforations by slitting means, and generating final cut-out by cut-out means at final stage of manufacture process. Said perforations are provided to manufacture vehicle variants at suitable stage of the panel manufacturing process.
The process comprises steps of perforating the rear floor panel using lasers or any suitable method/technique, instead of fully cutting it at the beginning of the assembly process. The rear floor panel is perforated in the form of series of slits and tabs. The process of making slit on the floor panel retains strength of the panel and principle locating points (PLPs) on the panel which are required during the assembly process. The PLPs are used for floor panel location on fixture and for robotic griper handling during the assembling process.
The final cutout in the floor panel is generated by cutting tabs between said perforated floors after the complete welding of the vehicle. Further to the process of welding, the cars/vehicles are sent for cationic electro deposition (CED) and painting process. Alternatively, the cutout can also be generated even after painting process, with a special care to prevent rusting in the area where cutting is done. The new process is used in producing new variant of the rear floor panel along with original panel product. The problems associated with productivity loss due to line shutdown, odd processes like plasma cutting, costly laser cutting equipments, additional space, manufacturing process related problems and exclusive manpower are completely resolved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of a typical car body shell with a rear floor panel.

FIG. 2 shows a perspective of a typical robotic welding set-up in automobile weld
line sheet metal panel with strengthening design features.
FIG. 3 shows a weakened rear floor panel after providing a cut-out or cutting the
strengthening features on the finished car body.
FIG. 4 shows a perspective view of the vehicle rear floor panel with perforations/slits
to retain the strength of the panel, according to present invention.
FIG. 5 shows a perspective view of the car body with a perforation on the rear floor,
according to present invention.
DETAILED DESCRIPTION OF THE INVENTION
The embodiments herein provides a process for forming cutout in floor panel for vehicles, comprising providing perforations on said floor panel along said cutout path before the panel welding/during panel manufacturing process, Slitting said perforations by slitting means, and generating final cut out by manual cut out means at final stage of manufacture process. Said perforations are provided to manufacture vehicle variants at suitable stage of the panel manufacturing process
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.
A perspective view of a typical car body shell 2 with a rear floor panel is as shown in FIG. 1. The rear floor panel 8 comprises radial curvatures 9 and strengthening ribs 10. The strengthening ribs 10 and curvatures 9 are provided to impart strength and stability to the rear floor panel 8. To generate a now product variant, the rear floor is to be cut-out on the finished car body 2.

FIG. 2 shows a perspective of a typical robotic welding set-up in automobile weld line and rear floor panel with strengthening design features. During sheet metal stamping process, a work hardening takes place and a panel 8 becomes rigid and strong. The strengthening ribs 10 and curvatures 9 are provided in the panel to impart strength and stability to the rear floor panel 8. Then the floor panel 8 is loaded on welding fixture 6. During floor panel 8 loading, the operator will locate and position the floor panel 8 on the fixture 6 by engaging principle locating holes 11 and 12 on principle locating pins 7. A handling robot 3 is fitted with pneumatic griper 4. During panel 8 handling from one station to another, the robotic pneumatic griper 4 is located with panel 8, by engaging principle locating pin 5 with principle locating hole 11. The robot will grip and transfer the panel 8, to next station in welding line.
FIG. 3 shows a weakened rear floor panel after providing a cut-out or cutting the strengthening features on the finished car body. As shown in FIG. 3, the cut out is generated by cutting with pneumatic saw. When the panel is cut in the strengthened area to generate cutout 1, then the panel 8 looses its strength and stability. Also it will be difficult to handle such a weak panel 8, by operator hands or by robot 3 with griper 4 (FIG. 2). As the principle locating holes 11 and 12 on the panel are removed by generating the cut off and the panel 8 can not be located on the fixture 6 or griper 4. The above mentioned process is very costly. Also installation of robotic laser cutting system will have several problems. Hence a process according to present invention is provided to generate the cutout during the panel stage instead of cutting on finished body.
FIG. 4 shows a perspective view of the vehicle rear floor panel with perforations/slits to retain the strength of the panel, according to present invention. With respect to FIG. 4, the rear floor panel 8 is perforated in the form of series of slits 13 and tabs 14 (non perforated area) along the cutout path, instead of fully cutting it at the panel

stage. The slits 13 are obtained by using suitable slitting techniques such as laser or plasma or press tool cutting depending upon the volume requirement. The sheet metal panel 8 is removed after the welding process. The perforation process according to present invention retains the strength of the panel and the principle locating holes 11 and 12, which are required for location on the fixture 6 and griper 4 respectively.
FIG. 5 shows a perspective view of the car body with a perforation on the rear floor, according to present invention. The complete car body shell 2 with perforated slits 13 is welded as per regular welding process. The principle locating holes 11 and 12 is provided for locating the floor panel 8 on the welding fixture 6 and robotic griper handling, as they remain intact due to panel perforation. The final cutout 1 is generated by cutting tabs 14 between the perforated series of slits 13 manually by simple hand held power tool or suitable cutting tools after the complete car body shell is welded. According to present invention the final cutout 1 (as in FIG. 3) is generated after welding process. After welding process the body shell 2 is sent for cathodic electro deposition (CED) and painting process. Alternatively the cutout 1 (as shown in FIG.3) can also be generated, even after painting process in trim and chassis fitment line, with special care of preventing rusting in the area where parent metal is exposed to atmosphere. Wherein said cutout space is used to mount modules such as batteries etc. in an electric driven vehicle.
ADVANTAGE:
• To provide a perforated sheet metal at rear floor panel in vehicles to retain its strength and principle locating points, which are necessary for car welding process.
• To retain the strength of the vehicle frame during manufacturing process and generate the cutout only at the final stage of the panel manufacturing process.

• To develop the new product variants along with the original product in mixed production mode.
• To provide as low cost solution with minimum line modification and for fast introduction of variant / modification.

We Claim:
1. A process for forming cutout in floor panel for vehicles, comprising;
providing perforations/slits on said panel along said cutout path before the panel
welding/during panel manufacturing process;
cutting said perforations by slitting means;
generating final cut-out by using cut-out means at suitable stage of vehicle
manufacture process;
Said perforations are provided to manufacture vehicle variants at suitable stage of the
panel manufacturing process.
2. The process according to claim 1, wherein said perforations are provided in the form of a series of slits and tabs.
3. The process according to claim 1, wherein said slitting means includes cutting by using laser or plasma or press tool etc depending upon volume requirement.
4. The process according to claim 1, wherein said perforation/slits retains the
strength of said floor panel and principle locating holes required for locating a fixture
and griper during floor panel manufacturing process respectively.
5. The process according to claim 1, wherein said cutout is generated by cutting tabs manually by using any hand held power tool between perforated series of slits after complete car body shell is welded.
6. The process according to claim 1, wherein the final car body with generated cutout is sent for cationic electro deposition (CED) and painting process.

7. The process according to claim 1, wherein said suitable stage for generating cutout includes after welding process or after painting process or trim and chassis fitment line with special care preventing rusting of the panel area which is exposed to atmosphere.
8. The cutout generated on sheet metal panel of by said process as clamed in claims 1 to 7.
9. The vehicle fitted with perforated sheet metal manufactured by said process as claimed in claims 1 to 7.
10. The perforated sheet metal product manufactured by said process to generate
cutout as herein described with reference to accompanying drawings.