FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
A Device For Measurement Of Axle Skewness Of A Vehicle
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
Babalal Sahebji Mulani, Narayan Dattatraya Jadhav & K. Gopalakrishna
An 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 particularly describes the invention and the manner
in which it is to be performed.

FIELD OF INVENTION
This invention relates to a device and more particularly to a gauge, which will be used for the axle skewness measurement of vehicle.
BACKGROUND OF INVENTION
In automobiles, tire life is the most concerning factor for the owner of vehicle in order to have lowest possible operating economy. This is very much true for the commercial vehicles fleet owners having bulk number of tires usage with its considerable operating cost. To avoid any of the non-uniform wear on the tire, the steering geometry and axle skewness adjustment of the vehicle should be done in given intervals of kilometers. The improper alignment of axles with respect to each other and chassis of vehicle is called as axle skewness. This misalignment will cause continues pulling of vehicle on either side of vehicle resulting in non-uniform wear on the tires. This invention mentions a simple and robust gauge, which can be used for axle skewness measurement of vehicle.
SUMMARY OF INVENTION
The main object of this invention is to provide a device for enhanced accuracy in the measurement of axle skewness of vehicle.
Yet another object of this invention is to provide a device having simple in construction and cost effective.
Yet another object of is to provide a device having better performance.


According to present invention a device for axle skewness measurement of a vehicle comprising, a displacer having internal threads and a outer ring at one end, said outer ring located in a collar, a main screw having outer threads and threaded to said displacer, a plurality of cross links hinged to said collar, a plurality of fingers hinged at end of said main screw, the other end of said cross links are hinged to said fingers, a locator provided at the end of said main screw and a vertically located marker in a bracket connected to said collar.
BRIEF DESCRIPTION OF THE DRAWING
Figure 1 shows schematic of device for axle skewness measurement of a vehicle.
DETAILED DESCRIPTION OF INVENTION
Referring now to the drawing 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.
The device for axle skewness measurement of vehicle is basically a mechanical gauge shown in figure 1. For the measurement of axle skewness the vehicle needs to be parked on a flat, horizontal surface. This device can be used for the vehicles having any number of wheels. To measure the axle skewness the reference points needs to be marked on the surface by using said device, which will represent the respective wheel locations of vehicle. After marking the reference points from each vehicle with the help of said device, the vehicle needs to be moved from the marking area.
Now referring to figure 1, wheel rim edge (15) and wheel hub (16) are the part of vehicle wheel over which the device for axle skewness measurement of vehicle will be fitted. A displacer (1) is a hollow tube with internal threading along the length to which a displacer handle (12) is fitted at the end. The displacer handle (12) is fitted on the displacer such a way that its center axis is perpendicular to the center axis of a displacer (1). The displacer (1) is having an outer ring (4) at its other end, which can be fitted in a collar (3). The main screw (2) is a hollow metal tube with the external


threading on its surface along the length. The main screw (2) center axis is matching with the center axis of displacer (1). The thread size of displacer (1) and main screw (2) are same by which the displacer (1) can be fitted over the main screw (2). The main screw (2) is fitted with a locator (13) at its outer end axially. The locator (13) is a metallic device with a pointer at its one end, which will touch the hub frontal area during the measurement. The locator (13) can be moved along the axis of main screw (2) to maintain the constant distance between each wheel to be measured with the help of markings done on its surface. The locator (13) is fitted in the end portion of main screw (2) in such a way that its axis is matching with the axis of main screw (2). The main screw (2) is also fitted with an inclinometer (11) on its top surface. The longitudinal axis of inclinometer (11) is matching with the axis of main screw (2). Three fingers (5), one end is pivoted on a finger pivot (14) while the other end is fitted with a finger tip (7). Three fingers pivot (14) are fitted on the main screw (2) peripherally with an angle of 120 degrees from each other. The finger pivot (14) hole center-axis is perpendicular to the center axis of main screw (2) so that fingers are hinged to rotated in a plane parallel to the axis of the device. The finger tip (7) is provided with the grove by which the finger (5) will have a firm grip over the wheel rim edge (15).Three cross links (6) to transfer the movement of collar (3) to fingers (5) One end of cross link (6) is pivoted on the finger (5) link and the other end is pivoted on the collar pivot (8). A collar (3) is a metallic disc having inner 'LP grove, which can be fitted over the outer ring (4) of a displacer (1). A circular relative motion between collar (3) and outer ring (4) is possible, where the collar (3) will be in stationary position. The collar (3) center axis is matching with the center axis of main screw (2). A marker bracket (18) is fitted at the bottom portion of the collar (3) whose longitudinal axis is parallel to the center axis of main screw (2). A marker (9) is having a tip with the help of which a reference mark can be created on the flat, horizontal surface over which the vehicle is parked. The marker center axis is perpendicular (vertically located) to the main screw (2) center axis. A stopper is provided at the top of marker to arrest the excessive movement.


Now referring to figure 1, for the fitment of said device on wheel rim edge (15), the displacer (1) needs to be rotated in anticlockwise direction with the help of displacer handle (12). The main screw (2) or fingers (5) can be hold during the fitment as these are the non-rotating parts of a device. The anticlockwise movement of displacer (1) will cause a linear movement of it due to the threading. The outer ring (4) of displacer (1) will be also rotating in the inside grove of collar (3). The collar (3) will be in stationary position but due to linear movement of displacer outer ring (4) caused by anticlockwise rotation will push the collar (3) towards outside. This linear movement of collar (3) will also push the cross link (6) towards outside resulting in expanding the fingers (5) peripheral diameter. This movement of finger (5) will push the finger tips (7) to hold the wheel rim edge (15) firmly. The horizontal application of said device can be confirmed with the help of inclinometer (11) fitted on the main screw (2). Fingers (5) needs to be readjusted if the horizontal fitment of said device is not observed. The three fingers holding a wheel rim circle will result in getting the wheel rim or wheel hub center directly. The axis (17) of the device will match with the wheel rim or wheel centre of the vehicle. The locator (13) can be then pulled through main screw (2) end portion and can be touched to the wheel hub surface, which will be the center of the hub. The marking done on the locator (13) will define the distance between said device and the hub surface, which can be replicated on the other wheels of vehicle to be measured. A marker (9) can be then dropped on the surface to mark a reference point of wheel under measurement.
The complete procedure described above needs to be repeated for each wheel of the vehicle, which will form a matrix of measuring points. After marking all reference points of all wheels the vehicle will be moved from the measuring surface and then the further measurement of axle skewness of vehicle can be carried out.
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.