A. Title of the invention
Universal Fixture for holding and testing of various high pressure Jacks used on
Military Aircraft.
B. Field of invention
The field of invention is in the Overhauling of Fighter aircraft and the invention is a
methodology for design of holding fixture for high pressure jacks for serviceability testing.
C. Background of Invention
There was no methodology holding the jacks during overhauling process of
Jacks used in aircraft for Landing gear.. Flaps and Air B,rake movement etc.
There was no prior facility available tc hold the high pressure jacks, as the system for testing was devised/ developed by the indigenous efforts and on the basis of the requirement of the customer.
D. Summary of the Present Invention
Design, development and fabrication of universal fixture for holding and testing of various high pressure Jacks used on Military Aircraft. This invention is used to check the serviceability of Jack used on military aircrafts for Landing gear, Flaps and Air Brake movement etc. A pressure of about 4000 psi was to be induced in the jacks for the testing its serviceability on the aircraft before clearing it for its fitness to be used on the aircraft. The testing is one of the important part of the serviceability check. Holding the Jack for the serviceability was one of the important facts which was to be addressed for the safety of the personal working on the job.
E. Brief description of drawings
FIG.1 Illustrates the diagram of the invented and various views of Jig

FIG.2 Illustrates the Orthogonal view of jig
F. Detailed description of invention
Main Undercarriage Jack, Air Brake Jack and Flap Jack of Military Aircraft are
overhauled and tested for its serviceability as per the recommended procedure. The
servicing of these units comprises disassembly, cleaning, paint removal, NDT, assembly
and testing. All the three units are different in size, shape and function. Previously no
fixture was available to hold these units for serviceability testing. The technician has to
manage some means and hold these units on the hydraulic rig test bed to carry out the
testing.
Hence, there was requirement to design, develop and fabricate three individual fixtures to carry out the testing. The initial drawings were prepared and the fixture was fabricated in Machine shop with minimal available resources. The fixture was tested and found very useful to carry out the required testing. Now it is used to carry out the regular testing for all three units.
The fixture is mounted on a base plate of thick steel (1)with one V shaped Holding plate(2) and one guide column(3). These items are firmly welded with each other in a way shown in figure below. Further, One holding bar (4) is mounted on one side of Holding plate/support (2) and a Knurled nut with screws at other end. These are used for aligning and tightening the holding clamp assembly (5). The guide column (3) and holding bar screw (4)will be holding the jack with the help of Holding plate support assembly.

Main Undercarriage Jack, Air Brake Jack and Flap Jack of Military Aircraft are overhauled and tested for its serviceability as per the recommended procedure. The servicing of these units comprises disassembly, cleaning, paint removal, NDT, assembly and testing. All the three units are different in size, shape and function. Previously no fixture was available to hold these units for serviceability testing. The technician has to manage some means and hold these units on the hydraulic rig test bed to carry out the testing.
Hence, there was requirement to design, develop and fabricate three individual fixtures to carry out the testing. Innovative ideas were brought forward to design such a universal holding fixture which can be used to hold the testing units of all without adversely affecting the serviceability of the units under test. The initial drawings were prepared and the fixture was fabricated in Machine shop with minimal available resources. The fixture was tested and found very useful to carry out the required testing. Now it is used to carry out the regular testing for all three units.

The fixture is an important invention in terms of holding the jack for testing the serviceability with high pressure fluid. The fluid is filled in the jack and tested for its leakage or any damage to the jack due to filling of high pressure liquid. This ensures the serviceability of the jack under high pressure conditions on aircraft. It consists of following metallic & non-metallic parts:
1. Base plate (1)
2. Holding plate/support (2)
3. Guide column (3)
4. Holding bar (4) •
5. Holding clamp Assembly (Screw bar and clamp)(5)
6. Support plate (6)
7. Knurl Nut with screw(7) Construction:
The fixture is mounted on a baseplate of thick steel(l)with one V shaped Holding plate(2) and one guide column(3). These items are firmly welded with each other in a way shown in figure below. Further, One holding bar (4) is mounted on one side of Holding plate/support (2) and a Knurled nut withscrews at other end. These are used for aligning and tightening the holding clamp assembly (5). Theguide column (3) and holding bar screw(4)will be holding the jack with the help of Holding plate support assembly.
Function :
The fixture so designed will be holding the jack firmly between the
holding plate/support (3) and Holding clamp assembly (5) to avoid
any slip/movement during testing.
The jack to be tested is connected through various connecting pipes
for filing the hydraulic fluids and is mounted on the fixture for
pressurized filling of fluid.
From the inputs of the jack the fluids are filled with pressure and
the other end of the jack is closed.
The fixture is developed using of metallic components manufactured out of machining and assembled by welding and screwing mechanism
CRITERIA FOR OBTAINING IP PROTECTION
1. Universalfixture for holding multiple sizes (thickness) of jacks.
2. The outer surface of the jack is not damaged by holding it with tight grip during testing, despite heavy pressure is being applied for leak testing.
Yes , As this is the requirement of customer for minimal overhauling cost and maximum reliability

Declaration Statement/NOC
1. I /We declare that all statements made herein are true to the best of my/our knowledge.
2. I/We hereby declare that, I/We have read the IPR Policy 2021 and are in agreement with the contents therein.
3. I/We hereby agree to assign all rights, title and interest to Hindustan Aeronautics Limited and agree to execute all documents as requested, assigning to Hindustan Aeronautics Limited, my/our rights in any IPR filed on this invention, and to cooperate in the protection of this invention and its subsequent commercialization.
4. I/We hereby agree to retain all necessary documentation and provide the same to the Organization in order to enable the organization to pursue IP protection for the invention,
5. I/We hereby agree to refrain from making any publication/public use of the invention that can prejudice the organization's ability to pursue IP protection under applicable laws.
6. I/We hereby agree that the obligations mentiorie'd herein continue irrespective of severance of employer-employee relationship between HAL and the undersigned.