FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003


PROVISIONAL SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
Torsional And Conical Stiffness Measuring Rig
APPLICANTS
TATA MOTORS LIMITED, an Indian Company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Mr. Praful L Bonde, Mr. Sripathi Krishnan,
Mr Anand Kulkarni, Mr Anirudh Deshpande
And Mr Mayuresh Deo
All are Indian Nationals
of TATA MOTORS LIMITED an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India

PREAMBLE TO THE DESCRIPTION
The following specification describes the invention.


FIELD OF INVENTION
The present invention discloses structure which enables to perform the Torsional and Conical stiffness measurement of rubber bushes with inner and outer metallic sleeves. Hysteresis of the rubber bushes during operation is critical along with the stiffness which defines the physical characteristic of any system. This innovation enables us to measure hysteresis along with the stiffness values. Further more the friction in any assembly where rubber bushes are used can be derived from the hysteresis values obtained from the rig. Conical stiffness measurement is quite complex to measure and the fool proof system is not available, this rig enables to measure torsional and conical stiffness different fixturing.
BACKGROUND OF INVENTION
Conventional method of measuring torsional and conical stiffness is with an assumption which makes it less precise. Fig 1 shows the conventional method of torsional and conical stiffness measurement. The force is applied on defined distance from the bush center to produce torque on the test bush. Force direction does not change with respect to movement of the rod attached to outer sleeve; where as the inner sleeve is fixed. In ideal condition the force applied in this system should be normal to the rod so pure torque will be applied. This assumption makes the conventional method less precise. To overcome these kind of problem and to have direct torque and angle measurement the Torsional rig is designed.
In conventional method inner sleeve is constrained and the loading is done on the outer sleeve. As the inner sleeve diameter is less, some time it becomes difficult to constrain the sleeve. If outer diameter is fixed with rod or plate this also becomes problematic when it is required to do the uniform loading on the bush.
30 MAR 2009

OBJECTS OF INVENTION
The purpose of invention is to measure the torsional and conical stiffness of rubber bushes accurately with minimum assumption considered during measurement as the stiffness is derived parameter of displacement and load, easy operation and cost effective- This rig is designed considering the drawback in conventional measurement method. Torsion rig overcomes the constraining difficultly observed in conventional method. This is achieved by constraining the outer sleeve with chuck holding with three line contact and torque is given to the inner sleeve.
For Conical stiffness measurement the constraining is done to inner sleeve, where bush is mounted horizontally. Outer sleeve is clamped in the fixture which is attache to the torque cell on the top.
The stiffness measured in conventional method needs extra care as the assumption consideration and difficult in operations. Constraining the bush and the loading with lever becomes difficult. These difficulties are considered during the designing of torsional & conical rig with direct angle and torque measurement.
BRIEF DESCRIPTION OF INVENTION
The torsional & conical stiffness measurement rig enables the characterization of bushes for torsional and conical loading behaviors. The design considerations for the rig are focused on minimum assumption for measurement, constraining, safety and ease of operations.
The rig is vertically mounted on four columns fixed on ground. Refer Fig [3] for the construction details of the rig. Torsional and Conical rig is basically assembly of five parts
1. Controller
2. Top cover box containing motor, torque and angle sensor

3. Vertical column consist T slot for up / Down movement of bush holding
fixture
4. Base made of four columns.
5. Computer - enables the instant analysis of the measurement.
Different fixture is designed to measure Torsional and conical stiffness, along with the stiffness the graph also gives the hysteresis, which can be derived in to friction vahies for further analysis.
Controller is attached to the rig, enables the digital control of the rig and this is connected to the computer for data transfer and analysis. A software program is designed for plotting the online graph, instant analysis and data management- It becomes easier for the engineer to control the test parameters and data collections and process with the software. The interface between rig, controller and computer makes the rig more users friendly.
DETAILED DESCRIPTION OF INVENTION
The Torsion and Conical stiffness rig is basically vertical structure; consist of five parts mounted on four column base. The various following parts are assembled together.
1. Top cover box containing motor, torque and angle sensor
2. Vertical column consist T slot for up and down movement of bush holding fixture
3. Base made of four columns.
4. Controller
5. Computer - enables the instant analysis of the measurement.
Controller and computer are for the synchronization between the machine and the

controls, please refer the fig [3] for further details. The rig structure is consisting of three parts top cover box, vertical column and base.
Top cover box is a closed structure consists of motor, drive arrangement, torque and angle sensors. The torque sensor is connected to fixture for holding bush sleeve to be tested. The motor is mounted on the vertical column, the torque and motion is transmitted to the torque sensor though the gear assembly, this gear assembly is amplified to required level of torque for the torque required for the stiffness measurement. The shaft is connected to the output gear connected to sensor and other end is connected to the fixture.
Vertical column is rigid structure mounted on base table, which connects part between the base and the top cover box. T-slot is provided on the vertical column for the height adjustment of movable table on which the bush mounting fixture is located. The movable table is connected to the base top table through lead screw. This lead screw enable the height adjustment by moving the lever, this make table constraining from two sides, one through the support of lead screw and the back side movable table face with T-slots. Fixture holding the bush is mounted on the movable table. According to bush size and fixture height the movable table height is adjusted .please refer figure [5] for further details.
Base structure supports the rig with four columns and is covered with a top plate. This column is kept at sufficient height which enables the ease in operations for the person operating the rig. The base structure is rigid enough to support the rig during testing.
Controller is the connecting media between the rig and the computer. This enables the interface and digital controls. The panel located on the controller display the torque & angle values helps during the initial preloading, pre cycles and tests. Instant display on the controller helps to understand the test to the person working.


If any uncertain reading displayed on the display the person working can instruct the test so that the safety can be insured.
Computer connected to the rig enables the data storage and data management of the tests conducted on the rig. The controller works as interface and gives the data to the computer. A software developed for the setup shows the instant display the torque and angle reading on the computer display at the time of test. Derived parameter like stiffness, hysteresis are the output of the test. Makes the required analysis of the test during minimum time.
Method of mounting
I. This rig is vertically mounted on a fixed table. The table is fixed to the ground.
II. A vertical column is mounted on the table which is perpendicular to the table top. At the top of the column, top cover box containing motor, torque and angle sensor are fixed.
HI. Vertical column consist of T-slot for up and down movement of bush holding fixture.
IV. Drive is given through a motor, which is mounted on a vertical column. This is connected to a vertical shaft on which a load cell is mounted.
V. This vertical shaft is attached with rotary sensor along with the load cell to measure rotary moment.
VI. For torsional measurement Proper fixtures are designed to hold the inner sleeve of test piece, so that desired torque can be applied through vertical shaft. The outer diameter of the test piece is held in the chuck. Chuck is mounted on a movable stand on table top to hold the outer diameter of test piece. Please refer fig 6 for details. For conical stiffness measurement bush is mounted horizontally and inner sleeve is constrained. Where as the outer sleeve is clamped in

fixgture and the top edge of the fixture is connected to the vertical shaft fixed to torque cell.
VII. During conical stiffness measurement the fixture constraining inner sleeve, where as for torsional stiffness the chuck is supported by the movable table. This movable table is attached to the vertical column though T-slot in the vertical column.
VIII. A control panel with display board is provided with the rig to operate this rig.
IX. Control panel is having both automatic and manual control mode as a safety feature to. operate this rig.
X. Computer is connected to enable the instant analysis of the data generated.
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.
Dated this 30th day of March 2009

(Karuna Goleria) of De PENNING & De PENNING
TATA Motors Limited By their Agent & Attorney