1. Title of the invention
Special Tool for Riveting on Contoured/Curved Surfaces of Aircraft.
2. Field of invention
This invention is related to the manufacturing, repair and quality assurance of Aircraft structures. Various structural sheet metals, ribs, frames and stringers on the aircraft are riveted with standard solid rivets. For riveting purpose, standard bucking bars along with pneumatic rivet gun is used. A bucking bar is the one that is used for squeezing the tail of rivet. The invention is a Special Tool which is adapted to a standard rivet driver for riveting on contoured surfaces of Aircraft.
3. Use of invention
The tool invented and fabricated in house by the technical team prevented damages to the skin of Dorsal Fin / curved areas of structure which were prone to damages using conventional rivet drivers. The invented tool is used for riveting on contoured/curved areas of the structure of aircraft without defects like unevenness, surface protrusion of rivet head etc.
4. Prior art
In the prior method, a flat faced rivet driver was used for riveting on a contoured/curved surface like the Mini Dorsal Fin skin of a fighter aircraft.
5. Draw backs of prior art
In the prior method, a flat faced driver was used for riveting even on a contoured/curved surface like the Mini Dorsal Fin skin which caused dents on the skin (structural member of the aircraft) due to the usage of a flat faced driver. Protrusion of rivets and damage to the skin may occur due to the use of improper rivet driver.

6. Comparison between prior art and present invention
Prior art:A flat faced rivet driver was used for riveting on contoured/curved surface of the structure like the Mini Dorsal Fin skin.
Present Invention: A cun/ed additional tool was used on the rivet driver for riveting on contoured/curved surfaces like the Mini Dorsal Fin skin. This invented tool eliminated unevenness, protrusion of rivets, dents on the skins and increased the life of riveted joints.
7. Aim of the invention
Aim of the invention was to develop a tool which can be used on the contoured/curved surface like fuselage/fairing skins thereby avoiding unevenness, protrusion of rivets, dents on the skins and increase the life of riveted joints.
8. Summary of the present invention
As a standard practice rivets are squeezed by a pneumatic rivet gun with driver on head side of the rivet and with a bucking bar on tail side of the rivet. While applying force with the gun on head side, a bucking bar is holding on tail side of the rivet which makes the tail portion to squeeze. The invented tool which was fabricated in house by the technical team is curved in shape and due to this curved shape, defects like unevenness and surface protrusion of rivet head were eliminated. Damages to the skin of Mini Dorsal Fin or any other contoured/curved surface which were prone to damages using conventional flat shaped drivers were also eliminated.
9. Brief description of drawings
Fig.1 Special Tool and the part of aircraft structure (Mini Dorsal Fin) where it is
used. Fig.2 Special Tool and rivet driver.

Fig.3 Special Tool fitted to rivet driver.
Fig.4 Limitation of the existing rivet driver.
Fig.5 Special Tool.used for riveting on a contoured surface of aircraft structure.
Fig.6 Special Tool.
10. Statement of invention
For riveting on aircraft structures, a standard flat shaped rivet driver was used even on contoured/curved surfaces also. This resulted in defective riveted joints. The tool invented and fabricated in house by the technical team which is curved in shape was tried for riveting on contoured/curved areas of the structural parts of aircraft. This resulted in good quality riveted joints without defects like unevenness, surface protrusion etc. It also prevented damages to the skin of Mini Dorsal Fin/contoured surfaces of structure which were prone to damages using conventional drivers.
11. Detailed description of invention
Special Riveting Tool is a square shaped (25 mm X 25 mm) and curved on one side which is made up of alloy steel and fabricated by milling& counter boring process. This Special Riveting Tool was then fitted/adapted to an already available standard rivet driver which is normally used for riveting on flat surface areas of Aircraft. Usage of this invented tool resulted in good quality riveted joints without defects like unevenness, surface protrusion etc. It also prevented damages to the skin of Mini Dorsal Fin/contoured surfaces of structure which were prone to damages using conventional rivet drivers.

Claims
We claim
1. The Special Tool used for riveting on contoured/curved surfaces of the aircraft structure and it's design.
2. The curved shape given on the Special Tool.