DESC:FIELD OF INVENTION

The present invention relates to toe-measurement in automobiles. In particular, the present invention relates to toe-measurement in tractors. More particularly, the present invention relates to toe-measurement in tractors by means of a digital toe-measurement gauge.

BACKGROUND OF THE INVENTION

Automobile wheel alignment is essential for limiting the tyre wear to some extent. Particularly, by adjusting the wheel angles for keeping wheels straight, it is ensured that the direction of travel is also straight and true, i.e. the wheels and thus tyres are not "pulled" to one side (further, by adjusting the angles of wheels to keep the wheels inclined by 2 degrees inside, it is ensured that the wear and tear of the tyres will also be less). The primary angles are the basic angle alignment of the wheels relative to each other and to the car body and these include camber, caster and toe.

For tractor operations, toe trueness in of utmost importance. ‘Toe’ means the symmetrical angle that each wheel makes with the longitudinal axis of the vehicle as a function of the static geometry and kinematic and compliant effects. The tractor front tyre should always have a toe-in within the range of 0 to 6 mm. In conventional arrangement, a manual gauge is used to set this toe-in of the tyres. This manual adjustment of the toe-in substantially increases the operator’s fatigue, results in inaccuracies in toe-measurements and often, this measurement process is quite time-consuming.

PRIOR ART

US7324916 B1 discloses a gyroscope used in an alignment measuring device for checking and adjusting alignment of a vehicle. The device includes an "x" and a "y" digital inclinometer working in concert with the gyroscope to measure various angle related to vehicle alignment. The alignment system is based on the use of a gyroscope in one embodiment, but not limited to a ring laser gyro, which may include x and y axis inclinometers associated with the ring laser gyro housing and a radio communications transceiver indexed to the frame centerline or other fixed data plane or point of a vehicle chassis. The invention also includes the method of using a gyro scope, such as a ring laser gyro, in an alignment system and the actual use of a gyro based alignment system.

However, this gyroscope based wheel-alignment measuring device is quite complex and costly.

CN103884518 A discloses a method for achieving four-wheel positioning and detection of an automobile by the adoption of an attitude sensor. According to the method for achieving four-wheel positioning and detection of the automobile by the adoption of an attitude sensor, in order to achieve four-wheel positioning, a wheel gesture collector and a four-wheel positioning computer host instrument are adopted, the wheel gesture collector is mainly composed of three MEMS micromechanical inertial navigation modules, a microprocessor, a wireless Bluetooth sending module, and a power supply, and the four-wheel positioning computer host instrument is mainly composed of a wireless Bluetooth wheel signal receiving module, a computer, a 3G/GPRS communication module, a displayer, a printer and a power supply. The method for achieving four-wheel positioning and detection of the automobile by the adoption of an attitude sensor has the advantages that due to the research and development of the instrument, omnibearing measurement of four-wheel positioning of the automobile can be achieved conveniently, and the instrument is suitable for passenger cars, buses, medium passenger and freight vehicles, high-speed passengers vehicles, passenger cars, heavy trucks, special vehicles and the like. The instrument has the remarkable advantages of being flexible, accurate, convenient to use, and efficient. This attitude sensor based device for obtaining true four-wheel positioning including a wheel gesture collector, four-wheel positioning computer host instrument.

However, the wheel gesture collector device disclosed in this document is quite complex and expensive.

DISADVANTAGES WITH THE PRIOR ART

The following are the disadvantages with the toe-measurement discussed with reference to the manual measurement as well as disclosed in the prior art documents cited above:

• Manual toe-measurement increases operator’s fatigue.
• Results are not accurate enough.
• Involves a time-consuming process.
• Conventional toe-measurement devices in market are very expensive.
• Existing devices require large space.
• Available devices cannot be moved easily.

Therefore, there is a need for developing a gauge for toe-measurement in tractor wheels, which is cheap, accurate and mobile and which requires least space to operate. Operating any such toe-measurement gauge should also be less time-consuming and easy to use in order to reduce the operator’s fatigue.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

An object of the present invention is to provide a toe-measurement device for tractors, which is substantially cost-effective to manufacture.

Another object of the present invention is to provide an electronic toe-measurement device for tractors, which gives accurate toe-measurements.

Still another object of the present invention is to provide an electronic toe-measurement device for tractors, which can be made in-house.

Yet another object of the present invention is to provide an electronic toe-measurement device for tractors, which requires minimal time for toe-measurement operations.
A further object of the present invention is to provide an electronic toe-measurement device for tractors, which reduces operator’s fatigue.

A still further object of the present invention is to provide an electronic toe-measurement device for tractors, which requires less space to work and store.

A yet further object of the present invention is to provide an electronic toe-measurement device for tractors, which is easily movable within the shop-floor.

These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.

DESCRIPTION OF THE INVENTION

In car industry, all four wheels are checked on a machine for toe, castor and camber. This machine not only costs about Rupees 26 lacs in India, but also requires more space and the checking process itself is a very time-consuming activity. On the contrary, tractors require only toe measurement.

Normally, the front tyres of a tractor should toe-in always within the range of 0 to 6 mm. In conventional toe-measurement practice, a manual gauge is used to set toe-in of tyres which causes operator’s fatigue, inaccuracies in toe-in measurements and the measurement process is also quite time-consuming.

In order to solve the drawbacks associated with the conventional manual gauge discussed above, a digital toe measurement gauge is developed. This gauge is portable and thus requires less space and also requires least time for toe measurement in tractors.

These are advantages with the digital toe measurement gauge developed according to the present invention as compared to the conventional machine deployed for measurement of all three parameters toe, caster and camber.
This digital toe measurement gauge comprises distance measurement sensor, motor and lead screw arrangement, Programmable Logic Circuit (PLC) and Human Machine Interface (HMI) or a display unit. This electronic toe-measurement gauge is also very cost-effective with cost just about INR 1 lac, i.e. about 4% of the conventional expensive gauges available in the market.

This digital gauge is portable, operating on Battery power and configured to move on five wheels. The gauge has two sliders, i.e. a LH slider and a RH slider which has a motorized lead screw mechanism. So, the slider moves in and out by means of a motorized actuation.

The target plates are mounted at four corners of slider and a distance measurement sensor is mounted on the gauge used for measuring the distance from the target plates. The sensors give the accurate distance value to PLC which performs all calculations and the results are displayed in HMI.

The operator checks in the display unit or HMI whether the toe-out or the toe-in is indicated. In case, the reading is beyond the specified limits of 0 to 6 mm, the HMI displays that the tractor toe measurement as TOE NOT-OK and if the measured value is within this specified range, the HMI display that the tractor toe measurement as TOE OK.

This offers a new approach substantially different from the conventional process of toe-measurement. A distance measurement sensor is used to measure toe of tyres of tractor.

This new method and electronic device is being used for the first time in tractor industry.

The device can be used under the tractor chassis and therefore, requires least space to operate. The distance measurement sensors are deployed in coordination with a Programmable Logic Controller (PLC) and a Human Machine Interface (HMI) to display results on a display for ease of working during tractor toe-measurements.
SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a digital toe-measurement system for checking and aligning toe-in of tractor wheels, the system comprising:

• a base frame movable on a plurality of wheels;

• at least a pair of support rods disposed on either side of the base frame;

• a target plate each fixed on each longitudinal end of each support rod;

• at least one swivel point each disposed substantially at the center of each support rod for adjusting the toe of the wheels;

• at least one lead screw connecting the swivel points for facilitating the swiveling movement of the swivel joint;

• a distance measurement sensor each fixed on target plates facing it and electrically connected to the electrical panel for toe-measurement of the respective tractor wheel;

• an electric motor for moving the lead screw to swivel the support rods for toe-adjustment;

• a battery-operated electrical supply connected to the electric motor;

• an electronic display unit or HMI;

• a programmable logic controller (PLC) for deploying the distance sensors;

• an electrical panel for connecting the distance sensors to the controller and the electronic display;

wherein the base frame supports all above components and sub-assemblies and is dimensioned to be easily slid under and removed from under the tractor axle without any hindrance to the accessibility thereof for tractor wheel toe-measurement and adjustment.

Typically, a distance sensor each is disposed on each target plate fixed on front and rear longitudinal ends of the support rods for conducting digital toe-measurement.
Typically, the electric motor is operated to facilitate swiveling movement of the target plates towards the tyres by means of the lead screw.

Typically, the Programmable Logic Controller stops the electric motor on the target plates touching the tyres.

Typically, the toe-reading is displayed on an electronic display unit or Human Machine Interface (HMI) as being “Not-OK” or “OK” or “Toe-in setting done”.

Typically, the toe-in setting is done by adjusting the tyres for alignment thereof, when the toe-in is displayed as “Not-OK”.

Typically, the “toe-in” operation is stopped and the front axle nut is locked, when the display or HMI displays the message as “Toe-in setting done”.

Typically, the motorized movement of the target plates pulls them away from the tyres or moves them inwards.

Typically, the system is battery-operated and mounted on the base frame thereof.

In accordance with the present invention, there is also provided a method of toe-measurement by using the aforesaid digital toe-measurement system, wherein the digital toe measurement method comprises the following method steps:

• Moving the toe-measurement system under the wheel axle and between the front tyres;

• Pressing the push button provided on the electrical panel to operate the motor in clockwise direction and thereby to push the target plates towards the tyres by rotating the lead screw;

• On the support rods touching the tyres, a stop command is issued to stop the motor;

• Reading the displayed toe-in value;

• Aligning the tyres to carry out toe-in operation, when the display reads Toe-in “NOT-OK”;

• Continuing toe-in adjustment by pulling the target plates away from the tyres or moving them inwards by motorized movement thereof, until the display reads “Toe-in setting done”; and

• Stopping the “toe-in” adjustment and locking the front axle nuts.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described with reference to the accompanying drawings, wherein:

Figure 1a shows a conventional manual gauge for checking toe-measurement of tractor wheels.

Figure 1b shows an operator using the manual gauge of Figure 1a for checking toe-measurement of tractor wheels.

Figure 2 shows a conventional sophisticated camera-based toe-measurement system used for checking toe-measurement in cars.

Figure 3a shows tractor tyre-wear on outer edges due to an excessive toe-out.

Figure 3b shows tractor tyre-wear on inner edges due to an excessive toe-in.

Figure 4 shows a schematic toe-measurement operation by using the toe-measurement system configured in accordance with the invention.

Figure 5 shows an exemplary toe-measurement system configured in accordance with the invention.

Figure 6a shows another schematic detailed view of the toe-measurement system configured in accordance with the invention.

Figure 6b shows the toe-measurement system of figure 7a depicting the swiveling action thereof.

Figure 7a shows a toe-measurement set-up using the system of Figure 5.

Figure 7b shows a close-up view of the distance measurement by using the system of Figure 5.

Figure 8a shows an actual view of HMI panel displaying toe-measurement as TOE NOT-OK.

Figure 8b shows another actual view of HMI panel displaying the toe-measurement as TOE-OK.

Figure 9 shows a detailed schematic constructional diagram of the toe-measurement system configured in accordance with the invention.

Figure 10 shows a schematic view of the digitization of toe-measurement by using the toe-measurement system configured according to the invention.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, the toe-measurement system configured in accordance with the invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention in any way.

Figure 1a shows a conventional manual gauge for checking toe-measurement of tractor wheels 2. The manual gauge consists of a distance rod 4 with a type feeler arm 6 mounted on LHS and RHS and supported on a stand 8 on either side thereof.

Figure 1b shows an operator Op using the manual gauge (4, 8) of Figure 1a for checking the toe-measurement of tractor wheels 2. However, the manual gauge is quite heavy (about 6 kg) and the operator has to continuously bend during this process of toe-measurement on each tractor. Often the operator has to bend 6-7 times and for durations of about 5-6 minutes per tractor for set the toe-in within specified limits. This bending comes to about 500 times for each operator in a normal shift-duty. Threfore, this manual toe-measurement causes extreme fatigue for the operator. Moreover, no measuring system is provided in this arrangement, thereby any such toe-measurement is not accurate enough and such toe-measurement inaccuracies lead to tyre wear even after using out this manual gauge.

Figure 2 shows a conventional sophisticated camera-based toe-measurement system used for checking toe-measurement in cars. Here, the operator Op uses a pair of measurement device 12, 14 attached to front and rear-wheels on either side of the car. A camera unit 16 captures the device position on all the wheels and displays the toe-values on a display unit 18 mounted on a stand 20. However, this system is very complex and requires major capital investment of the order of Rupees 25 lacs in India per unit.

Figure 3a shows a substantially higher tractor tyre-wear on outer edges due to an excessive toe-out.

Figure 3a shows the tractor tyre-wear on outer edges 22 of both the tyres 2 due to excessive toe-out, which is a substantially higher than on the inner edges 24 thereof.

Figure 3b shows the tractor tyre-wear on inner edges 24 of both tyres 2 due to excessive toe-in, which is substantially higher than on outer edges 22 thereof.

Figure 4 shows a schematic view of toe-measurement operation by using the toe-measurement system 100 configured in accordance with the invention for measuring toe-in/toe-out in the wheels 2 fitted on the front axle Ax of the tractor Tr. The wheels 2 are shown in toe-out position here. The system 100 is mobile and the operator Op can easily place it under the wheels 2 for checking the toe-in / toe-out to bring the wheels in alignment within the specified toe- limits.

Figure 5 shows a perspective view of the toe-measurement system 100 configured in accordance with the invention and explained in more details in Figures 6-8 below.

Figure 6a shows a schematic detailed view of the main components of the toe-measurement system 100 configured in accordance with the invention. It consists of a base frame 30, electrical panel 40, batteries 42, a plurality of laser-based distance measurement sensors 44, connected to the electrical panel via connections 46, a motor 48, a pair of swivel joints 50, a pair of target plates 52 fixed on a respective support rod 54 and disposed near either end thereof, a lead screw 60, controller 70 and HMI 80 or a display unit. The system 100 is mobile and the frame 30 and assemblies mounted thereon are dimensioned such that it can be easily disposed under the tractor axle with sufficient clearance between the frame 30 and the wheels as well as from the ground and the chassis. The wheel tyres 2 have an outer edge 22 and an inner edge 24 which are uniformly disposed about the central axis 26 thereof.

Figure 6b shows another schematic view of the main components of the toe-measurement system 100 of figure 7a depicting the swiveling action thereof. The arrows 110, 120 show the swiveling of the support plate carrying target plates, about the swivel joints 50 on the LHS and RHS respectively. All other components are same as shown in Figure 6a and are not repeated here again for the sake of conciseness of description.

Figure 7a shows a toe-measurement set-up using the system of Fig.5. The system 100 is brought under the front axle of tractor Tr by moving it on roller wheels 32. The support rods 54 carrying target plates 52 are now facing the inside faces of tyres 2. The procedure of toe-checking and the wheel alignment operation using the system 100 is described with respect to Fig.10 as follows.

Figure 7b shows the encircled views 56, 58 of laser point on target plate 52 during the distance measurement by using the system of Figure 5. The support rods 54 carrying the target plates 52 is facing the sensors 44 (not visible) to receive laser beams for calculating the actual distance between the tyres 2.
Figure 8a shows a typical display on the display panel HMI 80 panel to indicate the non-conformity of the toe-measurement with the specified toe-limits as Tractor (TOE) NOT-OK.

Figure 8b shows a typical display on the display panel HMI 80 panel to indicate the conformity of the toe-measurement with the specified toe-limits as Tractor (TOE) OK. The operator has to toe-in continuously until the display on HMI 80 reads Tractor (TOE) OK.

Figure 9 shows a detailed schematic constructional diagram of the toe-measurement system configured in accordance with the invention.

Figure 10 shows a schematic view of the digitized toe-measurement by using the electronic toe-measurement system configured in accordance with the invention. Accordingly, inside and outside motorized movement for different tractor model have to be carried out by using four target plates 52 fixed on the support rods 54 and using the laser-operated distance measurement sensors 44. This complete toe-measurement and adjustment operation requires only two personnel in contrast to at least four personnel used in case of manual toe-measurement gauge used until now.

WORKING OF THE INVENTION

The system 100 is moved under the wheel axle Ax and between the front tyres 2. The operator presses the push button provided on the electrical panel 40. The motor 48 operates in clockwise direction and the lead screw 60 pushes the target plates 52 towards the tyres 2. As the support rods 54 touch the tyres 2, the motor current increases and the PLC 70 on the electrical panel 40 issues a stop command to the motor 48. Now, HMI 80 displays the toe reading and according to the actual toe-reading displayed on HMI 80. If the HMI 80 reading is Tractor (Toe) NOT-OK, the operator goes for aligning the tyres 2 with the help of an assistant to carry out toe-in operation. Once the HMI 80 displays “Toe-in setting done”, the operator stop the “toe-in” operation and locks the nut of the front axle Ax.
Subsequently, the operator pulls the target plates 52 away from the tyres 2 or moved them inwards by motorized movement thereof. The complete unit is battery-operated which are mounted on the frame 30 of the system 100.

The system in accordance with the present invention can also be used subsequently to communicate the toe-measurement data to a Supervisory Control And Data Acquisition (SCADA) for remote monitoring and control to operate with coded signals over communication channels (using typically one communication channel per remote station).

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

The digital toe-measurement system for checking and aligning toe-in of tractor wheels configured in accordance with the present invention has the following technical and economic advantages:

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments.

The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description.

The description provided herein is purely by way of example and illustration. The various features and advantageous details are explained with reference to this non-limiting embodiment in the above description in accordance with the present invention. The descriptions of well-known components and manufacturing and processing techniques are consciously omitted in this specification, so as not to unnecessarily obscure the specification.

It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, the skilled person will recognize that the embodiments herein can be practiced with modification within the spirit and scope of embodiments described herein.

Therefore, the skilled person can easily make innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies, assemblies and in terms of the size, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention. It is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to implies including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention. ,CLAIMS:We claim:

1. A digital toe-measurement system for checking and aligning toe-in of tractor wheels, the system comprising:

• a base frame movable on a plurality of wheels;

• at least a pair of support rods disposed on either side of the base frame;

• a target plate each fixed on each longitudinal end of each support rod;

• at least one swivel point each disposed substantially at the center of each support rod for adjusting the toe of the wheels;

• at least one lead screw connecting the swivel points for facilitating the swiveling movement of the swivel joint;

• a distance measurement sensor each fixed on target plate facing it and electrically connected to the electrical panel for toe-measurement of the respective tractor wheel;

• an electric motor for moving the lead screw to swivel the support rods for toe-adjustment;

• a battery-operated electrical supply connected to the electric motor;

• an electronic display unit or HMI;

• a programmable logic controller (PLC) for deploying the distance sensors; and

• an electrical panel for connecting the distance sensors to the controller and the electronic display;

wherein the base frame supports all above components and sub-assemblies and is dimensioned to be easily slid under and removed from under the tractor axle without any hindrance to the accessibility thereof for tractor wheel toe-measurement and adjustment.

2. Digital toe-measurement system as claimed in claim 1, wherein one distance sensor each is disposed on each target plate fixed on front and rear longitudinal ends of the support rods for conducting digital toe-measurement.

3. Digital toe-measurement system as claimed in claim 2, wherein the electric motor is operated to facilitate swiveling movement of the target plates towards the tyres by means of the lead screw.

4. Digital toe-measurement system as claimed in claim 3, wherein the Programmable Logic Controller stops the electric motor on the target plates touching the tyres.

5. Digital toe-measurement system as claimed in claim 2, wherein the toe-reading is displayed on an electronic display unit or Human Machine Interface (HMI) as being “Not-OK” or “OK” or “Toe-in setting done”.

6. Digital toe-measurement system as claimed in claim 5, wherein the toe-in setting is done by adjusting the tyres for alignment thereof, when the toe-in is displayed as “Not-OK”.

7. Digital toe-measurement system as claimed in claim 4, wherein the “toe-in” operation is stopped and the front axle nut is locked, when the display or HMI displays the message as “Toe-in setting done”.

8. Digital toe-measurement system as claimed in claim 4, the motorized movement of the target plates pulls them away from the tyres or moves them inwards.

9. Digital toe-measurement system as claimed in anyone of the claim 1 to 8, wherein the system is battery-operated and mounted on the base frame thereof.

10. A method of toe-measurement by using the digital toe-measurement system for checking and aligning toe-in of tractor wheels as claimed in anyone of the claims 1-9, wherein the digital toe measurement method comprises the following method steps:

• Moving the toe-measurement system under the wheel axle and between the front tyres;
• Pressing the push button provided on the electrical panel to operate the motor in clockwise direction and thereby to push the target plates towards the tyres by rotating the lead screw;

• On the support rods touching the tyres, a stop command is issued to stop the motor;

• Reading the displayed toe-in value;

• Aligning the tyres to carry out toe-in operation, when the display reads Toe-in “NOT-OK”;

• Continuing toe-in adjustment by pulling the target plates away from the tyres or moving them inwards by motorized movement thereof, until the display reads “Toe-in setting done”; and

• Stopping the “toe-in” adjustment and locking the front axle nuts.

Dated: this day of 30th April 2016. SANJAY KESHARWANI
APPLICANT’S PATENT AGENT