FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
A fixture for measuring operating velocity of components and method of measuring thereof


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
BHALERAO JITENDRA D an Indian national 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 particularly describes the invention and the manner in which
it is to be performed.

FIELD OF INVENTION
This invention relates to measuring operating velocity of component using a novel fixture and in particular it relates to measuring the operating velocity of hinged components of vehicles such as door, bonnet and boot etc. using a novel fixture
BACKGROUND OF INVENTION
Door operating velocity measurement is one of the important tests for passenger cars and commercial vehicles. The objective of this test is to measure the minimum velocity for door operation. The data is useful for making necessary improvement in the product. The minimum velocity means minimum operating effort which is desired. The door has to get locked during the test. Currently this measurement is conducted by using the door velocity meter available in the market. The meter is located at suitable position on the car body panel near the door. The meter display unit shows the door velocity. The drawback of this system is that the fitment of the meter is difficult on curved surface like rear door, engine bonnet, boot etc. Further it is difficult to adapt the same meter to measure different vehicles and models.
In the proposed measurement unit, magnetic pick-up sensors and an existing data acquisition system are used to accomplish the object of the invention. The unit is made suitable for all vehicles.
OBJECTIVES OF THE INVENTION
The main object of this invention is to provide a measurement unit for velocity of door and bonnet closing operation.
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Another object of this invention is to provide a universal fixture suitable to all passenger
cars, LCV's and HCV's
Another object of this invention is to provide very simple to use and highly cost
beneficial fixture as it uses existing sensors and DAS
Yet another object of this invention is the possibility to use with bench mark vehicles
BRIEF DESCRIPTION OF THE INVENTION
A fixture for measuring operating velocity of components comprising: at least two magnetic sensors and a data logging system; said fixture consisting of a first plate and a second plate hingedly connected to each other; a suction cup fitted to the first plate, said suction cup adapted to be fixedly located; said magnetic pick up sensors located at a predetermined distance from each other and mounted on said second plate; said sensors capable of being adjusted in a direction perpendicular to said plate axis and locked at a suitable position.
A method of measuring operating velocity of component by using a fixture as described above comprising of the steps of:
• clamping the fixture at suitable position with the help of the suction cup
• adjusting the said plates and the sensors in such a way that said sensors get triggered by said moving component.
• connecting the output of the sensor to the data logger
• starting the data logger and operating the component,
• displaying the component closing velocity based on mathematical formula: Velocity = Distance/Time.
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A fixture and a method of measuring velocity of any hinged component such as "vehicle door", "vehicle bonnet", "vehicle boot" as also components in general engineering applications such as "door fitted with door closer" etc.
BRIEF DESCRIPTION OF DRAWINGS:
Fig. 1 shows a fixture for measuring operating velocity of components in accordance
with this invention.
Fig. 2 shows a fixture for measuring operating velocity of components as fitted on the
vehicle.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same.
Vehicle door velocity measurement device according to this invention comprises two magnetic pick-up sensors (2) and a data logger (not shown) for measuring the door veIocity(7). The fixture consists of a L- bracket made up of at least 2 plates (3, 4). A suction cup (6) is fitted to one of the plate (4) and the other plate (3) holds the magnetic pick-up sensors (2). The plate (3) holding the magnetic pick up sensors (2) is hinged (5) onto the other plate so that it can be rotated to locate the sensors at suitable position. The sensors (2) can be adjusted in a direction perpendicular to the axis of the plate (3) by screwing and unscrewing and can be locked at a suitable position. The sensor position is adjusted in such way that the sensor should get triggered. The distance between the magnetic pick-up sensors is fixed preferably at 100 mm. The complete assembly is fitted on the vehicle panel in such a way that the magnetic pick-up sensor will give a pulse as
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the door passes to it. The sensors will generate the pulse is door cuts the rnagnetic field of the sensor. The time between the 2 pulses will be recorded in the data logger. The time between the two pulses is recoded in the data acquisition system. By knowing the distance between the 2 sensors (example 100mm) and the time between the 2 sensor pulses, the door velocity can de calculated. The data logger can calculate the speed on the basis of mathematical formula.
Velocity = distance (100mm)/ recorded time (sec)
The fixture can be used for measuring door, bonnet or boot operating velocity.
Method of measuring
1) Clamp the fixture on the car body panel at suitable position with the help of suction
cup.
2) adjust the plate and the sensors so that the gap between the sensor and the door is 2-3
mm.
3) Connect the sensor's output to the data logger
4) Start the data logger and operate the door.
5) Display will show the door closing velocity based on mathematical formula,
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.
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CLAIM
1. A fixture for measuring operating velocity of components comprising: at least two magnetic sensors and a data logging system; said fixture consisting of a first plate and a second plate hingedly connected to each other; a suction cup fitted to the first plate, said suction cup adapted to be fixedly located; said magnetic pick up sensors located at a predetermined distance from each other and mounted on said second plate; said sensors capable of being adjusted in a direction perpendicular to said plate axis and locked at a suitable position.
2. A fixture as claimed in claim I wherein said sensor is provided with external threads to adjust at required linear distance.
3. A fixture as claimed in claim I wherein said fixture is adapted to be mounted in such a way that the said sensors will pick up pulse as the said door passes by and said pulses are fed to the said data logger which is configured to compute the velocity based on the data.
4. A fixture as claimed in claim 1 wherein said sensors are positioned in such a way that said sensors get triggered by said moving component.
5. A fixture as claimed in claim 1 wherein the said suction cup could be a magnetically actuated locking device
6. A fixture as claimed in claim I wherein the distance between the said magnetic pick up sensors is fixed preferably at 100mm.
7. A method of measuring operating velocity of component by using a fixture as described in claims 1 to 6 comprising of the steps of:
clamping the fixture at suitable position with the help of the suction cup
adjusting the said plates and the sensors in such a way. that said sensors get
triggered by said moving component.
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connecting the output of the sensor to the data logger
starting the data logger and operating the component,
displaying the component closing velocity based on mathematical formula:
Velocity = Distance/Time
8. A fixture for measuring operating velocity of components substantially as described in the description and depicted in the figures.
9. A method of measuring operating velocity of component substantially as described in the description and depicted in the figures.
Dated this 13th day of August 2008
TATA MOTORS LIMITED By their Agent & Attorney


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(Karuna Goleria) of DePENNING & DePENNING
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