DESC:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patent Rules, 2003
COMPLETE SPECIFICATION
(See sections 10 & rule 13)
1. TITLE OF THE INVENTION
A MODULAR TEST RIG SYSTEM FOR EVALUATION OF FALLING OBJECT PROTECTIVE STRUCTURES (FOPS)
2. APPLICANT (S)
NAME NATIONALITY ADDRESS
BEML LIMITED IN BEML Soudha, No 23/1, 4th Main S.R. Nagar, Bengaluru- 560027, Karnataka, India.
3. PREAMBLE TO THE DESCRIPTION
COMPLETE SPECIFICATION

The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION:
[001] The present invention relates to the field of falling object protective structures testing. The present invention in particular relates to a test rig system for evaluation of falling object protective structures (FOPS).
DESCRIPTION OF THE RELATED ART:
[002] The mining & construction or earth moving equipment cabin is intended to assure the operator of reasonable protection from falling objects of different sizes and masses. The laboratory tests are a means of evaluating the characteristics of the structures used to protect the operator from localized impact penetration and, indirectly, of the load-carrying capacity of the supporting structure to resist impact loading.
[003] Reference may be made to the following:
[004] Publication No. US2021381941 relates to a falling-object protective structures (FOPS) test assembly for carrying a FOPS test of a wall of cab of a heavy vehicle is configured to releasably carry a test ball for the FOPS test above a predefined distance above wall. The FOPS test assembly defines a closed path for test ball from its housing position to wall, and includes a handling means configured to assume a first condition in which they do not interfere with the passage of test ball through the closed path when ball passes through closed path in a first direction and a second condition in which handling means lock and hold test ball within the closed path once test ball passes again through the closed path in a second direction opposite to the first direction.
[005] Publication No. CN203688192 relates to an integrated test system of a falling object protection structure and a roll over protection structure. The integrated test system comprises an ROPS test system, an FOPS test system and a test piece clamping system. The ROPS test system and the FOPS test system are arranged on the same horizontal plane and use a fixed base workbench and the test piece clamping system in common. The FOPS test system is arranged on two parallel guide rails and can move back and forth along the parallel guide rails. The ROPS test system and the FOPS test system are provided with one foundation base construction and use a test piece multi-station clamping rotatable workbench and the fixed base workbench in common, and the FOPS test system moves to the test work position along the two guide rails buried in the foundation, so that the integrated test of the ROPS and the FOPS is realized, and the ROPS and FOPS performance tests of an engineering vehicle and a tractor are realized.
[006] Publication No. CN103776609 relates to an integrated test system and technology for a falling-object protective structure and a roll-over protective structure. The integrated test system for the falling-object protective structure and the roll-over protective structure comprises an ROPS test system, an FOPS test system and a test piece clamping system, wherein the ROPS test system and the FOPS test system are arranged on the same horizontal plane and share a fixed type base workbench and the test piece clamping system. The FOPS test system is located on two parallel guide rails and can move back and forth along the parallel guide rails.
[007] Publication No. CN218628995 relates to a fallen object protection device (FOPS) test system, which comprises a cab, a tool, a floor and a plurality of fasteners, the tool comprises a mounting plate, a mounting seat is provided with a first mounting through groove and a second mounting through groove, the floor is provided with a plurality of floor grooves, and the fasteners are connected with the first mounting through groove and the second mounting through groove. The fastener is movably contained in the first installation through groove and the second installation through groove in the length direction of the first installation through groove and the second installation through groove, and one end of the fastener is used for being inserted into a floor groove after penetrating out of the tool. According to the FOPS test system, the first mounting through groove and the second mounting through groove are formed in the mounting plate, so that the tool is suitable for multiple positions and multiple tests are carried out, a plurality of tools do not need to be prepared, material waste is avoided, meanwhile, a large number of manpower and material resources do not need to be used for disassembling and assembling a cab, and time and labor are saved.
[008] Patent No. US1901460 relates to testing machine and more particularly to the testing of the strength of materials by subjecting the material under test to a number of impacts imposed by a weight dropping from predetermined heights.
[009] Publication No. CN203148797 provides a test bed of a protecting structure for falling objects and overturning of a vehicle. The test bed comprises an installation seat, a falling object impacting device and a tipping loading device, wherein a protecting structure to be tested is fixedly arranged inside the installation seat; the falling object impacting device is arranged on the installation seat and above the protecting structure to be tested and provided with an impacting member capable of freely falling to impact the protecting structure to be tested; and the tipping loading device is arranged on the installation seat and applies a tipping acting force on the protecting structure to be tested. According to the test bed provided by the utility model, the structure is simple, the occupied area is small, and multiple test functions can be realized.
[010] Patent No. US3380289 relates to an impact testing apparatus for production testing automobile windows having mounting holes drilled along their edges. The sheets are cantilever mounted in a manner which simulates actual mounting conditions and a weight is dropped a predetermined distance to fall at a predetermined point on the surface of the sheet. Operation is semi-automatic so that when the weight is manually released from a latched position its downward movement actuates a lifting member which returns it in position to strike the next sheet. Upon return of the weight to the latched position the lifting member is automatically moved to an out-of-the-way position to permit free fall of the weight.
[011] Patent No. US4095839 relates to a falling object protective structure to protect the operator's cab of a hydraulic excavator or the like includes a canopy assembly mounted over the roof of the operator's cab which projects forward of the cab structure. The canopy is mounted on the cab structure at the front of the cab by a resilient member, whereby bending moments imparted to the canopy assembly by the impact of falling objects will not be transmitted to the cab structure. The protective structure is mounted directly to the top of the cab on the vertical support members inherent in the cab structure.
[012] Patent No. US6322133 relates to a protective apparatus for use in an industrial vehicle having an operator station including a protective member adapted to be connected with the vehicle so as to be generally disposed above the operator station. The protective member has a plurality of apertures configured to allow sound waves from vibrations of the vehicle to propagate through the protective member while generally preventing solid objects from falling through the protective member.
[013] Publication No. US2017176308 relates to an apparatus and method for measuring the impact performance of a target material comprising a hollow structure comprising an outlet end located above a target. The hollow structure is dimensioned to allow free movement of a drop test object through the outlet end. A trigger is located proximate to the outlet end and a retaining member is located proximate to the outlet end and coupled to hollow structure. The retaining member is configured to retain the drop test object in the hollow structure upon activation of the trigger.
[014] The International Standard ISO 3449: 2005(E) provides performance criteria for falling-object protective structures (FOPS). It recognizes that there are various classes and sizes of machines that operate in a variety of environmental conditions.
[015] Hence there is a need of modular test rig for testing of FOPS cabins of various types of mining and earth moving machineries.
[016] In order to overcome above listed prior art, the present invention aims to provide a modular test rig system for evaluation of falling object protective structures.
OBJECTS OF THE INVENTION:
[017] The principal object of the present invention is to provide a test rig system for evaluation of falling object protective structures.
[018] Another object of the present invention is to provide a test system that evaluates FOPS cabin and ensures protection of operator from falling objects.
[019] Yet another object of the present invention is to provide a test system that evaluates the characteristics of the structures used to protect the operator from localized impact penetration and indirectly of the load-carrying capacity of the supporting structure to resist impact loading.
SUMMARY OF THE INVENTION:
[020] The present invention relates to a test rig system for evaluation of falling object protective structures. The present invention is a modular test rig which ensures the availability of the test rig at any point of time without any restrictions of availability of resources like cranes, day light etc. A single acting pneumatic actuator is mounted on the cantilever beam. The weight will be clamped on to the Piston Rod of the actuator. When pneumatic supply is given, the piston rod will retract and the weight will fall vertically without any restraint, precisely on to the pre determined location on the cabin top.
BREIF DESCRIPTION OF THE INVENTION
[021] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments.
[022] Figure 1 shows test rig system for evaluation of falling object protective structures.
DETAILED DESCRIPTION OF THE INVENTION:
[023] The present invention provides a test rig system for evaluation of falling object protective structures. The invention provides rigid column (1) with cantilever beam (2) having pneumatic actuator ensures stability while hanging the dead weights (4) at a required height to gain potential energy. A single acting pneumatic actuator (3) is mounted on the cantilever beam (2) using compressed air hose (5). The single acting pneumatic actuator is mounted on the cantilever beam (2) which works on compressed air pressure of 2 bar.
[024] The weight will be clamped on to the Piston Rod of the actuator. When pneumatic supply is given, the piston rod will retract and the weight will fall vertically without any restraint, precisely on to the pre determined location on the cabin top.
[025] The present invention is a modular test rig which ensures the availability of the test rig at any point of time without any restrictions of availability of resources like cranes, day light etc. The rig has a pre determined accurate scale to mark the drop height, which makes the testing more precise. The cantilever beam, holds the weights rigidly without any oscillations when hanged. Also, the height of Cantilever lever beam can be adjusted as and when required. The Pneumatic Actuator acts very fast, ensuring quick release of the weight upon supply of air pressure making the test more realistic to the actual scenario that may occur.
[026] FOPS testing consists of 2 stages where 2 Dead Weights of different masses are used. (Refer Fig.1)
[027] For level – I testing, has a solid steel or ductile iron cylinder, a typical mass of 46 kg and a spherical contact surface diameter of between 200mm and 250 mm.
[028] For level – II testing, has a solid steel or ductile iron cylinder, a typical mass of 270 kg.
[029] The drop height of the falling object is defined as a function of its mass and provide the required energy.
[030] The test facility consists of a rigid column with a cantilever beam on top where the falling object mass is hanged. The drop height is adjustable restricted to a maximum of 4.5m by varying the location of Cantilever beam.
[031] The cantilever beam is firmly fixed by clamping its base with Anchor Studs and Nuts (Size : M48x5).
[032] The Dead weights are hanged to the Piston Rod end of the pneumatic actuator fixed on to the cantilever beam. The actuator operates for a minimum of 2 bar air pressure.
[033] Upon supply of pneumatic pressure, the dead weight will be released and the mass drops without restraint precisely on to the pre determined location on the cabin (6) top.
[034] The impact portion of the cabin is marked prior to the drop and normally will be the centre of its top surface at a radius of 200mm.
[035] Determine whether the FOPS enter the deflection limiting volume (DLV) during the test. DLV is orthogonal approximation of a large male, seated operator wearing normal clothing and a hard hat.
[036] It is made of a material that will indicate that any penetration by the FOPS, grease or other suitable material being permitted to be put on the lower surface of the FOPS cover to indicate such penetration. The DLV structure and its location shall be in accordance with ISO 3164. The DLV structure shall be fixed firmly to the same part of the machine as the operator’s seat and shall remain there during the entire formal test period.
[037] The test system evaluates FOPS cabin and ensures protection of operator from falling objects. It evaluates the characteristics of the structures used to protect the operator from localized impact penetration and indirectly of the load-carrying capacity of the supporting structure to resist impact loading.
[038] The method includes following steps:
1. Mount column structure on floor using anchor stud bolts.
2. Mount quick release mechanism on top of the column structure.
3. Mount spreader plate for mounting of FOPS test specimen.
4. Place the FOPS test specimen on spreader plate with mounting cushion as mounted on the equipment.
5. Place the DLV inside the FOPS with mounting stand on the floor plate and maintain the dimension of SIP as per the drawing.
6. Measure vertical and horizontal clearances after DLV is positioned inside the FOPS test specimen.
7. Mount the level-I falling object of 46.825 kg using quick release mechanism on top of the FOPS test specimen and maintain the required height of 2.97 m from top roof surface of the FOPS test specimen to achieve the required energy of 1,365 Joules.
8. The height of the level-I falling object shall be ensured using the calibrated measuring tape.
9. Connect the quick release mechanism with pneumatically operated directional solenoid valve.
10. Release the level-I test object so that it falls without restraint onto the FOPS.
11. Mount the level-II falling object of 270.201 kg using quick release mechanism on top of the FOPS test specimen and maintain the required height of 4.37 m from top roof surface of the FOPS test specimen to achieve the required energy of 11,600 Joules.
12. The height of the level-II falling object shall be ensured using the calibrated measuring tape.
13. Connect the quick release mechanism with pneumatically operated directional solenoid valve.
14. Release the level-II test object so that it falls without restraint onto the FOPS.
15. Measure final vertical and horizontal clearances after the completion of level-II FOPS testing.
16. Observe the minimum performance requirement that no penetration of any part of the FOPS structure into the DLV on imparting energy to the FOPS structure by the falling objects.
[039] In an aspect, the rig ensures the availability of the test rig at any point of time without any restrictions of availability of resources like mobile cranes, day light etc. It has a pre determined accurate scale to mark the drop height, which makes the testing more precise. The cantilever beam holds the weights rigidly without any oscillations when hanged.
[040] In another aspect, the height of cantilever lever beam can be adjusted as and when required. The pneumatic actuator acts very fast, ensuring quick release of the weight upon supply of air pressure making the test more realistic to the actual scenario the may occur.
[041] Numerous modifications and adaptations of the system of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the true spirit and scope of this invention.
,CLAIMS:WE CLAIM:
1. A test rig system for evaluation of falling object protective structures. comprises rigid column with cantilever beam (2) having pneumatic actuator (3) to ensure stability while hanging the dead weights at a required height to gain potential energy characterized in that the single acting pneumatic actuator (3) is mounted on the cantilever beam wherein weights are clamped on to the piston rod of the actuator and when pneumatic supply is given, the piston rod will retract and the weight will fall vertically without any restraint, precisely on to the pre- determined location on the cabin top.
2. The test rig as claimed in claim 1, wherein the rig has pre-determined accurate scale to mark the drop height, which makes the testing more precise.
3. The test rig as claimed in claim 1, wherein the cantilever beam, holds the weights rigidly without any oscillations when hanged. Also, the height of Cantilever lever beam can be adjusted as and when required.
4. The test rig as claimed in claim 1, wherein the cantilever beam, holds the weights rigidly without any oscillations when hanged and the height of cantilever lever beam can be adjusted as and when required.
5. The test rig as claimed in claim 1, wherein the drop height of the falling object is defined as a function of its mass and provide the required energy.
6. The test rig as claimed in claim 1, wherein a rigid column with a cantilever beam on top where the falling object mass is hanged and the drop height is adjustable restricted to a maximum of 4.5m by varying the location of Cantilever beam.
7. The test rig as claimed in claim 1, wherein the method includes following steps:
a) Mount column structure on floor using anchor stud bolts.
b) Mount quick release mechanism on top of the column structure.
c) Mount spreader plate for mounting of FOPS test specimen.
d) Place the FOPS test specimen on spreader plate with mounting cushion as mounted on the equipment.
e) Place the DLV inside the FOPS with mounting stand on the floor plate and maintain the dimension of SIP as per the drawing.
f) Measure vertical and horizontal clearances after DLV is positioned inside the FOPS test specimen.
g) Mount the level-I falling object of 46.825 kg using quick release mechanism on top of the FOPS test specimen and maintain the required height of 2.97 m from top roof surface of the FOPS test specimen to achieve the required energy of 1,365 Joules.
h) The height of the level-I falling object shall be ensured using the calibrated measuring tape.
i) Connect the quick release mechanism with pneumatically operated directional solenoid valve.
j) Release the level-I test object so that it falls without restraint onto the FOPS.
k) Mount the level-II falling object of 270.201 kg using quick release mechanism on top of the FOPS test specimen and maintain the required height of 4.37 m from top roof surface of the FOPS test specimen to achieve the required energy of 11,600 Joules.
l) The height of the level-II falling object shall be ensured using the calibrated measuring tape.
m) Connect the quick release mechanism with pneumatically operated directional solenoid valve.
n) Release the level-II test object so that it falls without restraint onto the FOPS.
o) Measure final vertical and horizontal clearances after the completion of level-II FOPS testing.
p) Observe the minimum performance requirement that no penetration of any part of the FOPS structure into the DLV on imparting energy to the FOPS structure by the falling objects.