This invention pertains to a Fuze Test Simulator System for testing Fuzes used in ammunition, assembled with or without Reserve Batteries. Often, due to non availability of proper simulation test equipment, the development activity of Fuze and Battery used therein had been hampered in the past. As is common knowledge, dynamic testing of Fuzes is an expensive and time-consuming activity, we have come out with a novel design of a simulator by which we can evaluate the performance of the Fuze, Fuze parts, Reserve Batteries, safety and arming mechanism etc.

Most of the artillery Fuzes use Reserve Batteries for the electrical power requirements. In the Reserve Batteries, the electrodes and electrolyte are isolated from one another. The Batteries are activated by the recoil force of the vehicle in which it is assembled and emitted from the gun, causing the electrolyte to come out of the Reserve bottle and enter the space between electrodes under centrifugal force and reacts with the electrodes resulting into continuous output of the electric power. Some other artillery Fuzes use turbo generators for their electrical power requirement. The simulator under our invention is capable of evaluating the performance of the in built Reserve Battery turbo generator as the case may be, while testing the Fuze. Similarly the performance of the safety and arming mechanism of the Fuze also can be evaluated by the simulator.

In fact, the real time firing often results in major cost overruns and inconclusive results. Further, it is often difficult to carry out the failure analysis as the Fuze gets destroyed when fired from the artillery gun and as such the question of recovery of the Fuzes does not arise. Hence, a need was felt for putting in place a comprehensive simulator which simulates the field conditions with a high degree of accuracy, before the Fuzes could be subjected to dynamic testing.

Many of the existing simulators available at present are having the following disadvantages which do not simulate the real life test environment of the artillery
gun firing. One such device has rifling mechanism inside the muzzle of the simulator to spin at the time of firing from the muzzle. This gives a spin to the test article for a very limited duration depending upon the muzzle design. In other words this gives more or less a fixed ratio of spin versus shock for each test muzzle used. Hence different types of simulators are required for testing different types of ammunition. In other models of test simulators the article under test is fired first without spinning and later on the fired fuze is spun and the data is recorded. This gives not only erroneous test conditions but also inaccurate test data.

Our invention is an universal simulator wherein the conditions can be preset before the tests and variety of tests can be carried out in the same equipment, for different types of fuzes / test articles.

In brief the simulator under our invention comprises of a movable test vehicle assembled with a case, which is suspended on bearings, which can withstand the applied shock, and spin. The case can hold the article to be tested. The case is capable of spinning at a preset rpm. The test vehicle is moved by the thrust developed by the expulsion system such as compressed air/ igniting compressed fuel air mixture / igniting an explosive device assembled, in the explosion chamber located behind the test vehicle over / along, a singular or plurality of guiding means such as wire / rail / rod/ tube/ channel/ angle frame/ flat bar / magnetic levitation platform; fluidized air bed, ambient air during flight etc. One of the preferred embodiments under this invention comprises of an electrically ignitable explosive device. There is a guiding means tightening arrangement. One such arrangement to keep the guiding means straight & parallel is by inducing tension with winch mechanism. Arrangements on the moving means are provided to decelerate the moving test vehicle, which is traveling under high acceleration.

All these parts are assembled suitably on a frame, so that it can be grouted on the ground firmly to withstand the axial and lateral forces developed during the simulation test of the Fuze. Means are also provided to tilt the frame. Provision also exists to recover the tested Fuze and measure various parameters to analyze the performance of the tested Fuze and its sub systems. Necessary instrumentation set up to monitor the speed of the test vehicle and the spin rate of the case holding the test article are also provided.

The state of the art Fuze Test Simulator under our invention is a technological break through, as it avoids the cumbersome process of testing and evaluating the Fuze both at the development stage as well as at the production stage, by simulating the real time artillery firing where the Fuzes are subjected to a simultaneous shock and spin. In addition, this equipment will be of much use for shelf life assessment, life extension and refurbishment of fuzes. When compared to the simulators available at present, ours is not only cost effective but also easy for operation, trouble free and maintain at less expenditure.

According to our invention a Fuze test simulator system comprising of a movable test vehicle (figure 3) assembled with a case (1), wherein the case is pivoted on to the test vehicle suitably, capable of holding the article to be tested firmly and having the provision for spinning the case at an rpm up to 100,000 by electrical or pneumatic means; An explosion chamber (3) with a piston mechanism 3(a) capable of creating a pre defined muzzle volume, which is settable, positioned at the rear end of the movable test vehicle wherein the piston of the test vehicle(8) is assembled at the front end of the explosion chamber (3) and a Means for activating the expulsion system (4) assembled in between the piston mechanisms (3a) and (8), capable of imparting a shock to the test vehicle (figure 3) ranging from 1 to 100,000 'g' in combination with pre defined volume selected, on activation of the expulsion system (4); A guiding means (5 ) selected from rail, wire, shaft channel, L angle, tube, magnetic levitation, fluidized air bed, a pre defined flight path using aerodynamic wings on the test vehicle in atmospheric air; A test vehicle(fig 3) capable of moving over the said guiding means due to the thrust developed on
activation of the expulsion system(4); A stopping arrangement (6) for the test vehicle, provided on the guiding means enabling to slow down and stop the test vehicle after an accelerated travel; Means for recovery of the tested article for data recovery and analysis; and a tiltable frame (7), capable of holding firmly the said items and grouting on the ground firmly to withstand the axial and lateral forces generated during the simulated testing.

Now the invention will be described in more detail with reference to the accompanying drawings bringing out a number of embodiments of the arrangement according to the invention in which figures and descriptions are given as under.

Fig.1- Fuze test simulator system.

Fig.2- Details of main assembly of Simulator marked in the fig.1

Fig.3- Test vehicle

Fig.4- Spin unit drive

Fig.5- Spin unit attached with the case holding the test article prior to spinning

Fig.6- Slip ring system

Fig.7- Muzzle assembly showing Explosion chamber and rear end (piston) of the test vehicle before activating the Expulsion system.

Wherein:

1. Case

2. Spin transmission means

3. Explosion Chamber

3(a) Piston to vary the Explosion chamber volume

4. Expulsion system

5. Guiding Means

6. Stopping arrangement

7. Frame

8. Piston of the test vehicle

9. Guiding means tightening arrangement

10. Spin Mechanism

11. RPM monitoring and Controlling unit

12. Slip rings

The Fuze test simulator system under our invention is comprising of the following main assemblies viz Muzzle assembly, Test vehicle. Spin Unit Assembly, Guiding means, deceleration system, means for Data measurement such as slip rings, electronic data acquisition device, telemetry device etc.

The Muzzle assembly (Figure 7) has an explosion chamber (3), the volume of which can be varied with a piston 3(a) of the explosion chamber, as per the 'g' force required to be imparted to the test vehicle (figure 3), with a provision for assembling the expulsion system (4) in the explosion chamber. The values of 'g' forces imparted to the test vehicle by means of this expulsion system is varied from 1 'g' to 100,000'g' as per the test requirement plan. The expulsion system can be selected depending on the desired 'g' value. In a preferred embodiment under this invention the expulsion system is having an electrically ignitable explosive device for activation.

The front end of the explosion chamber is assembled with the piston (8) of the test vehicle (figure 3) and the rear end is assembled with yet another piston (3a). Means for activating the expulsion preferably ignitable explosive device is located between the pistons (8) and (3a) which provides the driving force required for propelling the test vehicle. When the expulsion system is activated, pressure developed by the gas generated inside the chamber makes the test vehicle (figure 3) to move forward with a high velocity at the order of 50 m/s to l000m/s or as required, over the guiding means (5).

The test vehicle is provided with means to engage guiding means enabling the vehicle to move freely along the guiding means. Few of the said means attached with the test vehicle are LM Bearings or ball bushes or wheels or bushes, when the guiding means (5) selected are from wire / rail / rod/ channel/ angle frame/ flat bar.

The guiding means can be single one or more and are selected from suitable material preferably made of high strength material to withstand the axial and centrifugal forces generated due to the spin of the case and travel of the test vehicle.

In one of the embodiments with wire as the guiding means, the guiding means is kept straight and parallel and in tension by means of a tightening arrangement (9) for smooth travel of the test vehicle. One such arrangement to keep the guiding means straight & parallel is by inducing tension with winch mechanism. The length of the guiding means can be suitably adjusted as required ranging from 10 to 500 meters and is provided with a stopping arrangement (6).

The stopping arrangement has a decelerator mechanism for slowing down and stopping the test vehicle after the accelerated flight over the guiding means prior to recovery of the Fuze for data recovery and analysis. The guiding means are arranged in such a way that the test vehicle is allowed to accelerate initially and then decelerate and come to stop. In one of the preferred embodiments, this can be achieved by arranging from single or plurality of rail, wire, or shaft /channel/ L angle/ parallel to each other for a predefined path. The braking is achieved by bringing the wires close or widening them or by providing a second or third cable / rail on which the vehicle will rub its brake pad, so that the test vehicle experiences a frictional force and decelerates.

In another embodiment under the invention braking means can be a slide provided on the guiding means connected to a cable wound on a drum which is free to rotate which has a controlled electric / mechanical / hydraulic brake to control the unwinding of the drum resulting in to deceleration of the test vehicle.

In another embodiment under this invention, the guiding means can be a tube with or without slit in which test vehicle can travel. In such of those cases, the test vehicle can have properly aligned wheels or slides or piston. The diameter of the tube is gradually reduced towards the end by narrowing the slit in case of tube with slit which can function as Stopping arrangement (6). In case of tube without slit controlled friction can be created on the braking pad fitted to the vehicle, using a flat strip / flat ribbon / cable etc in side the tube to decelerate the vehicle.

In yet another embodiment, under this invention, the guiding means can be a magnetic levitation platform in which the test vehicle glides wherein the test vehicle and magnetic levitation platform will be provided with induced magnetic fields. The vehicle can be brought to a stop by withdrawing the induced magnetic fields at appropriate time and creating friction over a track etc.

In one another embodiment, under this invention, the guiding means can be fluidized air bed in which the vehicle can travel. The vehicle can be brought to a stop by withdrawing the fluidized air bed at appropriate time, and creating friction over a track etc.

In another embodiment where guiding means is not necessary, the vehicle with spinning case will be suitably modified by providing aerodynamic wings and will be made to fly to reach to the predefined target. Such systems will be of very much use when the test articles are to be subjected to simulation test involving flight trial in the atmospheric air along a specific flight path. Deceleration can be done by air spoilers in the wings/ parachute opening with timer devices provided on the test vehicle. Such a system would be of immense use for testing proximity fuze used in the artillery shells.

The test piece which is to be evaluated is assembled in a case (1) having a definite shape selected from rectangular, spherical, cylindrical, truncated double cone (bobbin shape) preferably bobbin shaped and is assembled in the test vehicle in such a way that it can rotate freely in the axial direction with respect to the explosion chamber/ piston of the test vehicle. In case of testing a complete Fuze with metal body, one can have either a case which will house the Fuze or a holder made of flanges of any suitable shape, which hold the Fuze from both ends by studs. The case / holder can be opened or closed to assemble the test pieces firmly. Once the testing is completed, the case is opened and the test piece is retrieved and evaluated. The case is connected to the spin unit by suitable Spin transmission means (2) such as (a). Radial fan/ coaxial fan fitted to case to spin the case by means of incoming air during flight (b). Any detachable coupling connected to an electric / air motor mounted on the main frame (7) which initiates the spin and gets detached once the vehicle leaves the muzzle and the spin sustains by the inertia of the case acting like a flywheel, (c) Case coupled to an air / electric motor fitted on the vehicle which moves along with the vehicle. The spin unit can be operated either electrically or pneumatically or by incoming air flow during the flight.

In its electrical version the spin mechanism (10) consists of a high speed motor with variable speed drive to vary the spin based on the test requirement. Similarly instead of electric motor with variable electric speed drive we can have variable air flow controller or air deflectors. The spin can be set between 0 to 100,000 rpm. Required rpm sensors are provided suitably to continuously measure the rpm of the case holding the test sample during its travel and even when the test vehicle is halted. A data acquisition system / instrumentation system is provided to monitor, measure and record the parameters such as rpm of the case (test article). Battery voltage, current drawn, velocity of the test vehicle, time of travel, set back force, pressure in the explosion chamber etc. In addition, the movement of the test vehicle is also video graphed by means of high speed camera / radar gun / video camera for analyzing the path of the travel of test vehicle as well as the spin of the case containing the test article. Measured data is recorded and is analyzed to evaluate the performance of the test sample as well as the equipment. The voltage is recorded through two slip rings(12) fitted on either end of the case which is having pivots. The slip rings are on pivots. Standard rpm controllers(11) of electrical/pneumatic controls are used for controlling the rpm of the test article.

All these parts are assembled on a frame (7) suitably, so that it can be grouted on the ground firmly to withstand the axial and lateral force developed during the firing and travel of the Fuze. The frame can be tilted to any angle based on the test requirements. The entire system is encased in housing, for protection against any external impediments, and also to protect the personnel handling the equipment in case of any accidents.

The requisite technology and equipment needed to build a test facility to simulate field environment had always been a major problem. For want of universal Fuze Test Simulator System under our invention, the common practice adopted by many was to subject the Batteries and the Fuzes to dynamic firing tests in proof ranges. But dynamic testing is an expensive and time-consuming activity, resulting in major cost overruns. Often failure analysis of the Fuze and Battery also becomes a difficult task. But the state of the art Fuze test simulator under our invention which can simulate the dynamic testing for evaluating the performance of Fuze and Batteries can give a lasting solution to this impediment. Key benefits of this invention can be summarized as under.

• Fillip to the development of Fuze and Batteries in the industry.

• Single platform for simulating field conditions and undertaking extensive testing of various types of Fuzes and the Batteries inside the Fuzes.

• Provides high level of reliability in testing of the Fuze and Battery at far reduced costs and time.

• Multiple systems of recorders can be simultaneously used to measure the data for high reliability and redundancy to ensure fail proof tests, measurements, and variety of analysis.

• All the tests can be done directly on the Fuze / Battery without wasting the artillery shells during the testing, qualification and acceptance stage prior to conducting dynamic testing in the range.

• Saving of costly artillery shells during the development stage of Fuze and Batteries.

• The Fuzes once tested can be safely and fully retrieved from the simulator and inspected after test to identify the problem area if any.

• Tests can be repeated several times on the same Fuze.

• Life extension tests and refurbishment of old Fuzes can be carried out more precisely and scientifically.

Although the invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, variations and modifications can be effected within the spirit and scope of the invention as described herein above and as defined in the appended claims.

We claim

1) A Fuze test simulator system comprising of a movable test vehicle (figure 3) assembled with a case (1), wherein the case is pivoted on to the test vehicle suitably, capable of holding the article to be tested firmly and having the provision for spinning the case at an rpm up to 100,000 by electrical or pneumatic means;

An explosion chamber (3) with a piston mechanism 3(a) capable of creating a pre defined muzzle volume, which is settable, positioned at the rear end of the movable test vehicle wherein the piston of the test vehicle(8) is assembled at the front end of the explosion chamber (3) and a Means for activating the expulsion system (4) assembled in between the piston mechanisms (3a) and (8), capable of imparting a shock to the test vehicle (figure 3) ranging from 1 to 100,000 'g' in combination with pre defined volume selected, on activation of the expulsion system (4); A guiding means (5 ) selected from rail, wire, shaft channel, L angle, tube, magnetic levitation, fluidized air bed, a pre defined flight path using aerodynamic wings on the test vehicle in atmospheric air; A test vehicle(fig 3) capable of moving over the said guiding means due to the thrust developed on activation of the expulsion system(4); A stopping arrangement (6) for the test vehicle, provided on the guiding means enabling to slow down and stop the test vehicle after an accelerated travel;

Means for recovery of the tested article for data recovery and analysis; and a tiltable frame (7), capable of holding firmly the said items and grouting on the ground firmly to withstand the axial and lateral forces generated during the simulated testing.
2) Fuze test simulator system as claimed in claims wherein the guiding means is capable of positioning straight , parallel and in tension by means of a tightening arrangement (9) preferably a winch mechanism for smooth travel of the test vehicle and can have length ranging from 10 to 500 meters and is provided with a stopping arrangement (6).

3) Fuze test simulator system as claimed in claim1 wherein the guiding means is not necessary, the vehicle with spinning case (1) is provided with aerodynamic wings capable of flying to reach to the predefined target in the atmospheric air along a specific flight path and also provided with air spoilers in the wings or parachute capable of opening with timer devices provided on the test vehicle for deceleration.

4) Fuze test simulator system as claimed in claim1 wherein the means are provided for holding the test article firmly in position in a case (1) capable of spinning, mounted on a pivot and positioned in the test vehicle which can freely move along the guiding means at predefined high velocities and capable of withstanding the axial and centrifugal forces generated due to the spin of the case and travel of the test vehicle during the testing and has a stopping arrangement (6) wherein the said guiding means are placed parallel to each other for a predefined path and capable of applying the brake by bringing the wires gradually close or widening them or by providing a second or third cable or rail on which the vehicle will rub its brake pad, so that the test vehicle can experience a frictional force and thereby decelerate and stop.

5) Fuze test simulator system as claimed in claims wherein the case(1) is connected to the spin unit by suitable spin transmission means (2) selected from a radial fan/Turbine or coaxial fan/Turbine fitted to case to spin the case by means of incoming air during flight; a detachable coupling connected to an electric motor with variable speed drive or air motor with variable air flow controller or air deflectors mounted on the main frame (7) which is capable of initiating the spin and gets detached once the vehicle leaves the muzzle , while sustaining the spin by the inertia of the case akin to a flywheel; an air or electric motor coupled to the case and fitted on the vehicle which can move along with the vehicle wherein the spin unit can be operated either electrically or pneumatically or by in coming air flow during the flight.

6) Fuze test simulator system as claimed in claims wherein case (1) holding the test piece is having a definite shape selected from rectangular, spherical, cylindrical, truncated double cone like bobbin shape and is assembled in the test vehicle (figure 3) in such a way that it can rotate freely in the axial direction with respect to the explosion chamber (3) assembled with the piston (8 ) of the test vehicle, and a holder made of flanges of any suitable shape, held from both ends by studs or a case is made use of if the article to be tested is a complete Fuze.

7) Fuze test simulator system as claimed in claims wherein the front end of the explosion chamber (3) capable of assembling with the piston (8) of the test vehicle (figure 3) and the rear end is capable of assembling with yet another piston (3a) and a Means for activating the expulsion system preferably an explosive device located between the pistons (8) and (3a) or even devoid of piston (3a) to adjust the volume of the chamber, enabling to provide the driving force required for propelling the test vehicle and wherein the said expulsion System (4) of the explosive chamber is capable of developing high gas pressure inside chamber when the said Means for activating the expulsion system is initiated causing to move forward the test vehicle at a high velocity at the order of 50 m/s to 1000m/s over the guiding means (5)

8) Fuze test simulator system as claimed in claims wherein the stopping arrangement (6) is a decelerator mechanism for slowing down and stopping the test vehicle after the accelerated flight over the guiding means selected from a tube with or without slit in which test vehicle can travel by means of properly aligned wheels or slides or piston wherein the diameter of the tube is gradually reduced towards the end by narrowing the slit in case of tube with slit and by means of braking pad fitted to the vehicle, using a flat strip / flat ribbon / cable or similar means inside the tube to decelerate the vehicle in case of tube without slit.

9) Fuze test simulator system as claimed in claims is capable of evaluating the performance of the Fuze, its sub assemblies and components, Reserve Battery, turbo generator, and safety and arming mechanism used in the Fuze functioning at a velocity between 50 m/s and 1000m/s with 1 to 100,000 'g' with or with out spinning up to an rpm up to 100,000, monitored by rpm sensors mounted on either side of the guiding means wherein provision exists for a data acquisition and instrumentation system such as herein described capable of monitoring, measuring and recording the parameters such as rpm of the case (test article), Battery voltage, current drawn, velocity of the test vehicle, time of travel, set back force, and pressure in the explosion chamber and the movement of the test vehicle.

10) A Fuze test simulator system substantially herein described with reference to and illustrated in figure 1 to 7 of the accompanying drawings.