FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
PROVISIONAL/COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
Device for cyclic test of hydraulic compensator of fighter aircraft
2. APPLICANT(S)
(a) NAME: HINDUSTAN AERONAUTICS LIMITED
b) NATIONALITY: INDIAN
(C) ADDRESS: SM(PP-SUROH), Aircraft Overhaul Division, Nasik
3. PREAMBLE TO THE DESCRIPTION
PROVISIONAL The following specification describes the invention.
COMPLETE The following specification particularly describes the invention and the manner in which is to be performed.

4. DESCRIPTION (Description shall start from next stage.) Refer Annexure I
5. CLAIMS (Not applicable for provisional specification. Claims should start with the preamble - "I/We claim" on separate page) Refer Annexure II
6. DATE AND SIGNATURE (to be given at the end of last page of specification)
7. ABSTRACT OF THE INVENTION (to be given along with complete specification on separate page) Refer Annexure III
Note:-
*Repeat boxes in case of more than one entry.
*To be signed by the applicant(s) or by authorized registered patent agent.
*Name of the applicant should be given in full, family name in the
beginning.
*Complete address of the applicant should be given stating the postal index
no./code, state and country.
*Strike out the column(s) which is/are not applicable.

Complete Specification of
Device for cyclic test of hydraulic compensator of fighter aircraft

1 Title of the Invention
Device for cyclic test of hydraulic compensator of fighter aircraft
2 Field of the Invention
The invention relates to electrical, mechanical and aerospace engineering in general and the specifically to fighter aircraft repair and overhaul.
3 Background of the Invention
The hydraulic system of fighter aircraft uses a fluid under pressure to dive loads or to move the hydraulic mechanisms. The hydraulic pump are used to generate the desire fluid pressure, multiple hydraulic system are used to increase the redundancy of system failure of fighter aircraft. The smooth operation of the hydraulic system is ensured by various elements like hydraulic accumulators, filters, pressure reducing valves, check valves and flow restrictors. In case of partial or complete failure of any hydraulic system, switches and warning units installed for automatic changing over from one hydraulic system to another. Pressure recording and indicating system is also desirable for continues recording and monitoring the parameter of hydraulic system. The external ground couplings are provided for suction line, pressure line and oil filling line. The circulated oil from pump is also cooled down by fuel-oil coolers. The hydraulic tank is a piston type closed hydraulic compensator intended for receiving oil from the system, compensation of oil volume during operation of the units and for providing oil pressurization in to the suction lines of the hydraulic pump
In case of removal, change or to replacement of the hydraulic compensator due to failure, performance of complete cyclic testing procedure is desirable some time mandatory to achieve the high quality standard of fighter aircraft. Cyclic testing is a tedious, time consuming and resource intensive process. There exists a need for portable and easy to operate device to carrying out cyclic test of hydraulic compensator that

provides the faster cyclic and less resource intensive process of testing for fighter aircraft.
3.1 Prior Art United States patent, Patent No.: US 0242694A1 dated Oct. 1, 2009 Patent title: The hydraulic system of aircraft, it describes about the general design aspect of aircraft hydraulic system. Invention describes about the general design aspect of aircraft hydraulic system more particularly, to a hydraulic system providing redundant operation to permit continued operation in the event of failure of one or more hydraulic system. Though it is related to an aircraft hydraulic system, it is not related to the testing of aircraft hydraulic compensator system on ground in cyclic manner to identify irregularities in aircraft hydraulic system.
United States patent, Patent No.: US 2364709 dated Dec. 12, 1944 Patent title: Portable hydraulic test stand for aircraft, it describes about the general aspect of portable hydraulic test stand use for aircraft. The invention is directed toward a portable hydraulic test stand use for testing of hydraulic system units, either while affixed to the aircraft or after removal from the aircraft. Though it is related to an aircraft hydraulic system, it is not related to the testing of aircraft hydraulic compensator system on ground in cyclic manner to identify irregularities in aircraft hydraulic system.
World Intellectual property organization, Patent No.: W0134153A1 dated Aug. 25,2016
Patent title: Portable hydraulic Brinell testing apparatus, it describes about a portable testing apparatus for Brinell test meeting the load time requirement of the ASTM E10 standard. Portable hydraulic Brinell testing

apparatus keeps the pressure constant during the test period despite creep from the indenter moving in the test piece and hydraulic leakage. Though it is related to an aircraft hydraulic system, it is not related to the testing of aircraft hydraulic compensator system on ground in cyclic manner to identify irregularities in aircraft hydraulic system.
4 Brief Summary of the Invention
The hydraulic system of fighter aircraft uses a fluid under pressure to dive load or to move the hydraulic mechanism. The hydraulic pump are used to generate the desire fluid pressure. The hydraulic tank is a piston type closed hydraulic compensator intended for receiving oil from the system, compensation of oil volume during operation of the units and for providing oil pressurization in to the suction lines of the hydraulic pump. In case of removal, change or to replacement of the hydraulic compensator due to failure, performance of complete cyclic testing procedure is desirable. Present invention is a device for cyclic test of hydraulic compensator of fighter aircraft which is portable and easy to operate device to carrying out cyclic test of hydraulic compensator that provides the faster cyclic and less resource intensive process of testing for fighter aircraft.
5 Detail Description of the Drawings
The invention can be better understood by reading the detail description of the disclosed embodiment followed by the accompanied drawings:
Figure-1: Block diagram of device for cyclic test of hydraulic compensator
of fighter aircraft.
Details of figure 1
1: Device for cyclic test of hydraulic compensator
2: Hydraulic compensator.
3: Rotating device.
4: Securing device.

5: Low pressure connecting element.
6: High pressure connecting element.
7: Electrical connecting element
8: Automatic pressure release mechanism.
9: Low pressure measuring device.
10: High pressure measuring device.
11: Insulation measuring device.
12: Circuit continuity measuring device.
13: High pressure supply system.
14: Low pressure supply system
15: Electric power supply system-1.
16: Electric power supply system-2
6 Detail Description of the Invention
A full understanding of the invention can be gained, when wherein parts are referred by the numerals read in conjunction with; Figure 1- Provide the block diagram of device for cyclic test of hydraulic compensator of fighter aircraft.
Cyclic test consist of high pressure and low pressure test of hydraulic compensator in a cyclic manner for testing the redundancy of unit. Device for cyclic test of hydraulic compensator (1) is made of metallic frame used for precise orientation of hydraulic compensator (2) at specific mounting point and properly secured by securing device (4) on the rotating device (3).
High pressure test: High pressure test is performed by connecting high pressure connecting element (6) to hydraulic compensator (2) and high pressure connecting element (6) was also connected with High pressure measuring device (10) and High pressure supply system (13). During testing of high pressure test, high pressure supply system (13) is connected with Electric power supply system-1 (15) which generate the

desired pressure and given to unit under test i.e hydraulic compensator (2), Serviceability check of hydraulic compensator is performed at high pressure test results are continuously monitored.
Low pressure test: Low pressure test is performed by connecting low pressure connecting element (5) to hydraulic compensator (2) and low pressure connecting element (5) was also connected with low pressure measuring device (9), Automatic pressure release mechanism (8) and low pressure supply system (14).During testing of low pressure test, low pressure supply system (14) is connected with Electric power supply system-1 (15) which generate the desired pressure and given to unit under test i.e hydraulic compensator (2) through Automatic pressure release mechanism (10) and low pressure measuring device (9). Serviceability check of hydraulic compensator is performed at low pressure test results are continuously monitored. During operation of hydraulic fluid filling to hydraulic compensator (2), hydraulic fluid filling is done at low pressure after complete filling, pressure is suddenly start increasing to avoid pressure increase Automatic pressure release mechanism (8) is connected, it release the valve for discharge.
Electrical connecting element (7) is connected to the micro-switch of hydraulic compensator (2), Insulation measuring device (11) and Circuit continuity measuring device (12) for measurement of the Insulation resistance and serviceability of micro-switch circuit. After completion of cyclic test, rotating device (3) is used to rotate the hydraulic compensator (2) to drain out the hydraulic fluid completely from the unit.

Claims
We Claim,
1. A device (1) for cyclic test of hydraulic compensator (2) of fighter aircraft,
comprising:
rotating device (3) on device (1) for orientation of hydraulic compensator (2) and secured by securing device (4);
hydraulic compensator (2) connected with high pressure connecting element (6), high pressure measuring device (10), High pressure supply system (13) and Electric power supply system-1 (15) for high pressure test;
hydraulic compensator (2) connected low pressure connecting element (5), low pressure measuring device (9), Automatic pressure release mechanism (8), low pressure supply system (14) and Electric power supply system-1 (15) for low pressure test;
and
electrical connecting element (7) is connected to Insulation measuring device (11) and circuit continuity measuring device (12) for measurement of the Insulation resistance and serviceability of micro-switch circuit;
2. The device claimed in Claim-1, is modular in design for easy cyclic test of hydraulic compensator (2) of fighter aircraft during ground testing.
3. The device (1) claimed in Claim-1, contain Automatic pressure release mechanism (8) which help in restricting the pressure after filling of fluid inside the hydraulic compensator (2).
4. The device (1) claimed in Claim-1 contain rotating device (3) on the device (1) for draining of fluid from the hydraulic compensator (2).