FORM 2
THE PATENT ACT 1970
[39 OF 1970]
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
[See Section 10 and Rule 13]
“A SYSTEM FOR MEASURING WEIGHT OF AN OBJECT AND METHOD
THEREOF”
Name and Address of the Applicant: TATA MOTORS LIMITED, Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai – 400001, Maharashtra, India.
Nationality: Indian
The following specification particularly describes the nature of the invention and the manner in which it is to be performed.

TECHNICAL FIELD
The present disclosure relates to a multi resolution precision load cell for measurement and more particularly relates to a load cell which enables the user to differentiate between precise and very small loads over higher capacity measurements.
BACKGROUND OF THE DISCLOSURE
Electromechanical force transducers are also known as load cells. Nowadays they are used for the conversion of the weight force to be determined into an electrical value. This electrical value is further processed into a suitable form of value. In order to display the measured value in units of weight and for the easy understand ability of the user, a display system is used which gives the weight measured in various units of weights and displays it in Kgs, pounds, grams etc for easy tabulation of the results. The load cells that are most frequently used are based on the strain gauge technique.
The load cells available are commonly having fixed resolution for a particular range and measuring in lower band may lead to inaccuracies and non linearities, hence different load cells are used as per the measurement range.
In some cases, there is always a need to have a single load cell which is required to have same accuracy in higher level as well as lower measurement range. For eg. There is a requirement to calculate difference in weight of automobile body before and after the painting process. It is difficult to find a single load cell which can continuously obtain the same accuracy.
Consider an application wherein user wants to capture the small change in its mass with respect to its original mass. If it is required to measure colour quantity deposited on BIW (Body in White) then the change in unit load is hardly 0.01% of the original weight. Since, the available load cells can measure loads with accuracy of 0.1% on FSD (Full Scale Deflection), it is very hysterical and the results will later not be accurate.
Proposed multi resolution device will be able to measure higher loads as well as small change in loads with equal accuracy. It can be used like a normal load cell and regular display can indicate the instantaneous readings.
Hence, there is a need to develop a method of measuring loads in dynamic condition and with higher precision.

OBJECTIVES OF THE DISCLOSURE
An objective of the present disclosure is to measure the smaller changes in load over higher ranges with very high accuracy and with very efficient and fast measurement tool.
One objective of the present disclosure is to measure the load variance without any interference in one go.
One objective of the present disclosure is to measure the instantaneous load values without changing their existing shifting arrangements.
STATEMENT OF THE DISCLOSURE
Accordingly the present disclosure provides a system for measuring weight of an object comprising at least one first load cell, wherein one end of a first load cell is fixed to a loading hook and other end of the first load cell connected to a load shaft, wherein said load shaft protrudes into a frame; a frame formed by protrusion of the load shaft, said frame is of predetermined shape consisting of top closed end and bottom open end; at least one rubber diaphragm placed at the bottom open end of the frame configured to support the protruded portion of the load shaft; at least one horizontal beam placed within the frame and is fixed to the protruded portion of the load shaft; plurality of second load cells configured to measure incremental changes of load are mounted on the horizontal beam; a locking mechanism placed outside the frame is provided to lock the load shaft under load condition; a height adjustment mechanism configured to adjust the locking mechanism along with the movement of the horizontal beam due to deflection of the load shaft under load condition and the method of measuring weight of an object comprising steps of; connecting first load cell to loading hook; connecting the object to be measured to a loading hook and determining the load using first load cell locking the load shaft by locking mechanism after attaining equilibrium readings from first load cell; fixing plurality of second load cells onto a horizontal beam and applying second iteration of loads; measuring the incremental changes in loads and tabulating the readings from second load cell; releasing the locking mechanism after all the loads are measured.

SUMMARY OF DISCLOSURE
The shortcomings of the prior art are overcome and additional advantages are provided through the provision as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.
In an embodiment of the disclosure a system for measuring weight of an object using a load cell is disclosed, the system comprises of at least one first load cell fixed to one end of a loading hook and other end of the first load cell connected to a load shaft. A frame is formed by protrusion of the load shaft and said frame is of predetermined shape consisting of top closed end and bottom open end. At least one rubber diaphragm is placed at the bottom open end of the frame configured to support the protruded portion of the load shaft. At least one horizontal beam is placed within the frame and is fixed to the protruded portion of the load shaft. Plurality of second load cells configured to measure incremental changes of load of the object are mounted on the horizontal beam. A locking mechanism is placed outside the frame is provided to lock the load shaft under load condition. A height adjustment mechanism is configured to adjust the locking mechanism along with the movement of the horizontal beam due to deflection of the load shaft under load condition. The locking mechanism and height adjustment mechanism work in synchronization with the load shaft and the load condition.
In an embodiment of the disclosure a load cell assembly is disclosed, wherein first load cell is capable of measuring high capacity loads from about 100kg to 1500kg and has a load resolution of +/- 0.1% of its full scale capacity and range varies from 0.1 kg to 3 kg.
In an embodiment of the disclosure a load cell assembly is disclosed, wherein second load cell is capable of measuring loads upto 10kg and have a load range of about 0.01 kg to 0.5kg.
In an embodiment of the disclosure a load cell assembly is disclosed, wherein the static deflection of the loading hook ranges from 10 mm to about 50 mm depending on the amount of load applied.
In an embodiment of the disclosure the method of measuring a weight of an object using load cell is disclosed. Said method follows steps of connecting first load cell to loading hook. The object to be measured is connected to a loading hook and measured using first load cell. The

load shaft is locked using locking mechanism after attaining equilibrium readings from the first load cell. The second load cells are fixed to a horizontal beam and second iteration of loads are applied and corresponding measurement of incremental changes in loads are tabulated using readings from second load cell. The locking mechanism is released once the entire loads are measured.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWING
The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:
Figure 1 illustrates exemplary system/arrangement used for measuring weight of an object using load cell. Also the figure shows arrangement of locking mechanism and its mechanical adaptations.
Figure 2 illustrates the construction details of high capacity load sensing elements.
Figure 3 illustrates the locking mechanism and height adjustment mechanism of the load cell.
Figure 4 illustrates flow chart of the method of working of the precision load cell.
The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better

understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.
Referring now to the drawings wherein the drawings are for the purpose of illustrating a exemplary embodiment of the disclosure only, and not for the purpose of limiting the same.
There exists no device which will be able to measure higher loads as well as small change in loads with equal accuracy.
Figure 1 illustrates exemplary system/arrangement used for measuring weight of an object using load cell. Also the figure shows arrangement of locking mechanism and its mechanical adaptations wherein, a high capacity first load cell (2) is fixed to a loading hook (1). The loading hook (1) in the present disclosure is used to carry high capacity loads. The other end of the first load cell (2) is connected to a load shaft (3). The first load cell (2) is a high capacity load cell and is capable of carrying loads ranging from 1000 Kg to 1500 Kg. A frame (4) of predetermined shape having a top enclosed end (5) and bottom open end (6), wherein the bottom open end (6) of the frame (4) has atleast one rubber diaphragm (7) placed at the mouth of the bottom open end (6). The rubber diaphragm (7) acts as a spring mechanism having a rubber stiffness ratio of 100 kg/mm. Due to the reaction on the rubber diaphragm (7) there will be a deflection of around 10 mm towards loading hook (1). The frame (4) is made up of high strength steel which take up most of the loads and stresses

developed. High strength steel has good fatigue properties, high work hardening rates and aging capabilities. Also high strength steels are available abundantly in wide variety of sizes, strength levels, chemical compositions and surface finishes making it apt for this application. After the first load cell (2) gives a definite reading, the locking mechanism (10) is used to lock the load shaft (3) in place. A horizontal beam (8) having plurality of second load cells (9) are adjusted in place with the load shaft (3) with the height adjustment mechanism (11) and fixed rigidly to the frame (4) using locking mechanism (10). Once the horizontal beam (8) having a second load cell (9) becomes active and it can be connected to signal conditioner for digital results.
Figure 2 illustrates the construction details of high capacity load sensing elements, the entire apparatus consists of a frame (4) having a top closed end (5) and a bottom open end (6). The bottom open end (6) of the frame (4) has atleast one rubber diaphragm (7) through which the protruded portion of the load shaft (3) is supported on the rubber diaphragm (7). During the load condition, the loading hook (1) takes up the weight, which is of high capacity loads. This produces a deflection on the load shaft (3). The rubber diaphragm (7) acts as a reaction spring with a rubber stiffness of 100kg/mm. The first load cell (2) will show a weight reading on its signal conditioner with static deflection of 10mm as the stiffness of rubber is 100 kg/mm. Due to high strength frame (4), the stresses and forces developed are equally distributed along the high strength steel frame (4). The first load cell (2) displays the weight to the user and once the load is settled to its equilibrium position, there will not be any deflection other than the initial deflection happening at the start. After settling down of the load the second load cells are fixed to the steel frame (4) using locking mechanism (10). The locking mechanism is selected from a group comprising screw type lock for easy engaging and disengaging of the locking mechanism. The plurality of second load cells (9) are placed on the horizontal beam (8) calculates high precision loads. After the first load cell (2) has achieved equilibrium weight. The second load cell (9) becomes alive and is connected to signal conditioner for digital results which will be captured during course of action. The complete load assembly containing both load cells active, can be taken through smaller load changes. Eg. Paint shop in automotive factory having a 1500kg bare cabin before entering into the paint shop. After completion of painting the weight rise is not more than a few grams i.e 100 to 150 grams. To ensure the painting quality and its repeatability, it is a must to measure the correctness of the paint quality. Hence when the bare cabin is taken into paint

shop change in small load will be captured by second load cell and the total load can be
addition of 2 load cells i.e
Total load (Kg.gms) = Load Cell 1 (Kg) + Load Cell 2 (gm)
Once the measurements are tabulated, the locking mechanism (10) can be released and load
can be released from load cell which will again deflect the rubber diaphragm back to its
original position.
Figure 3 illustrates the locking mechanism and height adjustment mechanism of the load cell, wherein the load shaft (3) deflects from its original position due to a heavy load. A locking mechanism (10) is provided on the outside of the frame (4) to lock the load shaft (3) after equilibrium position is achieved and allows the second load cell (9) to come into picture and activates the second load cell (9). Height adjustment mechanism (11) is used to adjust the height of the locking mechanism (10) in accordance with the load shaft (3). Due to the deflection caused for the load applied the height adjustment of the horizontal beam (8) has to be in synchronized with the load shaft (3).
Figure 4 illustrates a flow chart of the method of working of a precision load cell wherein the first load cell (2) connected to the loading hook (1) is put under heavy loads. The first load cell (2) is connected to a signal conditioner and the reading of the load is shown by a digital processor. The readings of the first load cell (2) are tabulated. A locking mechanism (10) is connected to the load shaft (3) and to the second load cell (9) is connected to the signal conditioner. The second iteration of load change (minute change in load) and correspondingly measure the loads on second load cell (9). The loads of first load cell (2) and second load cell
(9) are measured by adding both the loads to show the difference. The locking mechanism
(10) is disengaged and the load from the hook is removed.

REFERAL NUMERALS

1 Loading Hook
2 First load Cell
3 Load shaft
4 Frame
5 Top closed End
6 Bottom closed End
7 Rubber Diaphragm
8 Horizontal beam
9 Second load Cell
10 Locking Mechanism
11 Height Adjustment Mechanism

WE CLAIM:
1. A system for measuring weight of an object comprising;
At least one first load cell (2), one end of a first load cell (2) fixed to a loading hook (1), and other end of the first load cell (2) connected to a load shaft (3), wherein said load shaft (3) protrudes into a frame (4);
a frame (4) formed by protrusion of the load shaft (3), said frame (4) is of predetermined shape consisting of top closed end (5) and bottom open end (6);
at least one rubber diaphragm (7) placed at the bottom open end (6) of the frame (4) configured to support the protruded portion of the load shaft (3);
at least one horizontal beam (8) placed within the frame (4) and is fixed to the protruded portion of the load shaft (3);
plurality of second load cells (9) configured to measure incremental changes of load are mounted on the horizontal beam (8);
a locking mechanism (10) placed outside the frame (4) is provided to lock the load shaft (3) under load condition;
a height adjustment mechanism (11) configured to adjust the locking mechanism (10) along with the movement of the horizontal beam (8) due to deflection of the load shaft (3) under load condition.
2. The system for measuring weight of an object as claimed in claim 1, wherein first load cell (2) is capable of measuring high capacity loads from about 1000kg to 1500kg and has a load resolution of +/- 0.1% of its full scale capacity and range varies from 0.1 kg to 3 kg.
3. The system for measuring weight of an object as claimed in claim 1, wherein second load cell (9) is capable of measuring loads upto 10kg and have a load range of about 0.01 kg to 0.5kg.
4. The system for measuring weight of an object as claimed in claim 1, wherein the static deflection of the loading hook (1) ranges from 10 mm to about 50 mm depending on the amount of load applied.

5. The system for measuring weight of an object as claimed in claim 1, wherein the locking mechanism (10) and height adjustment mechanism (11) work in synchronization with the load shaft (3) and the load condition.
6. The method of measuring weight of an object comprising steps of;
connecting first load cell (2) to loading hook (1);
connecting the object to be measured to a loading hook (1) and determining the load using first load cell (2)
locking the load shaft (3) by locking mechanism (10) after attaining equilibrium readings from first load cell (2);
fixing plurality of second load cells (9) onto a horizontal beam (8) and applying second iteration of loads;
measuring the incremental changes in loads and tabulating the readings from second load cell (9);
releasing the locking mechanism (10) after all the loads are measured.
7. A system for measuring weight of an object and the method of measuring weight of
an object, are substantially as herein above described and as illustrated in
accompanying drawings.