[0001] The present invention generally relates generally to machines and methods for grading objects. Particularly, the present disclosure relates to an automated electro-mechanical grading machine for grading objects and a method for grading smaller sized objects.
BACKGROUND OF THE INVENTION
[0002] It is a tricky operation to deal with objects, typically, smaller sized objects while grading them due to the difficulties arises for holding/handling them, but these smaller sized objects also need to be hold or handled systematically for quality grading of individual smaller sized object owing to their variety of variations in external and internal features. Therefore, it is important to grade such small objects by proper holding and/or handling such smaller sized objects for performing effective analysis on individual basis and not on the bulk basis and for high quality grading.
[0003] To address basic problems of grading objects on individual , object to object basis, one such invention was developed which has been disclosed in Indian Application No. 994/CHE/2014 “An improved machine for grading small sized irregular objects and a process thereof” which focuses on the machine for grading small sized irregular objects comprising a feeding unit that facilitates feeding of object from where the pick and place unit can pick the small sized object and place it to the corresponding examination bed of the tray having plurality of examination bed forming one tray and plurality of such trays forming a conveyor and such plurality of trays are interlinked serially via chain links. Each examination bed is accommodated with at least one small sized object which is examined/analyzed by the imaging systems. Further, the invention comprises an electromagnetic non-contact mechanism for automated ejection of the small sized objects

which are held and handled effectively for increased throughput of the grading machine which grades multiple small sized objects in a single pass, where each ejected small sized objects are collected in respective grade container.
[0004] Each examination bed with embedded magnet is having a pre-determined bed area of capacity to hold at least one small sized objects where size of objects is ranging from 5mm to 75mm according to the prior art grading machine. When same pre-determined sized examination bed of prior art grading machine is deployed for grading comparatively smaller sized objects, where size of objects is ranging from 2mm to 25mm, the same pre-determined sized examination bed would not provide efficient grading results with higher throughput due to use of more than the required bed area for holding the smaller sized objects (which creates more than required magnetic flux while dealing with comparatively smaller sized objects), which causes disturbance in properly/firmly holding, analyzing each such small sized object with imaging system and similarly due to continuous vibrations/shocks received by such smaller sized object of each examination bed during conveying of such small sized objects, the entire throughput of the overall grading machine is affected for being ineffective in holding and/or handling smaller sized objects during conveying and ejecting, thereby making the grading machine of prior art highly inefficient for grading comparatively smaller sized objects. [0005] FIG. 1 and FIG. 2 are illustrated in the light of existing grading machine disclosed in Indian Application No. 994/CHE/2014.
[0006] Referring to FIG. 1 is a standard graph illustrating behaviour of the magnetic flux density with the changing values of applied magnetic force and the formation of hysteresis loop in the permanent magnet embedded inside each examination bed according to the prior art grading machine. Referring to FIG.1 is a graph illustrating a proportional relationship between the magnetic flux density and the applied magnetic

force where ‘B’ represents magnetic flux density and ‘H’ represents the magnetic force. It shows the magnetic flux density increases with the increase in magnetic force until it reaches to a saturation point, the magnetic flux density does not increase further once it reaches to its saturation point. The magnetic flux density does not relax back to zero even if the imposed magnetic force is removed due to high remanence/retentivity of the permanent magnetic material. In the existing grading machine of 994/CHE/2014, the material used in the permanent magnet shows such retentivity after every ejection (magnetisation of permanent magnet) due to which there are chances of dropping comparatively smaller sized objects from the same pre-determined sized examination bed with more flux than required to eject smaller sized objects outside the grade container. [0007] Referring to FIG. 2 the graph illustrates the lower saturation point of magnetic flux density with the changing values of applied magnetic force in the electromagnet coil placed inside ejection unit according to the prior art grading machine. It creates a requirement of such a temporary magnet which shows although a negligible retentivity after every de-magnetisation, such negligible retentivity should also be minimized to a great extent by applying an external coercive force so as to overcome the problem of remanence/retentivity after every de-magnetisation to achieve high magnetic flux density during magnetisation for maintaining higher saturation point of magnetic flux density for accurate handling and/or ejection of smaller sized objects.
[0008] As none of the prior art so far explicitly mentions/explicitly provides effective solution for stable holding and/or handling of smaller sized objects during grading, thereby avoiding improper holding with minimised movement/shaking of comparatively smaller objects and /handling/ejection of comparatively smaller sized objects during grading to achieve efficiency of grading machine for accurate inspection, conveyance

and ejection of comparatively smaller sized objects accurately in the grade container, so as to increase throughput of the prior art grading machine (994/CHE/2014). SUMMARY OF THE INVENTION
[0009] The present invention has been devised to overcome above mentioned technical problems. The present invention is embodied in a grading machine for grading smaller sized objects and related method for grading smaller sized objects by using a grading machine. The grading machine is devised for grading any type of smaller sized objects, naturally occurring, artificially or synthetically manufactured, typically smaller sized objects.
[0010] In accordance with one aspect of the invention, disclosed is the grading machine for grading smaller sized objects. The grading machine comprises of: at least one controller; an object introducing unit, an in-feed unit, a singulator, a plurality of examination beds, at least one conveyor, a plurality of dampers, a plurality of permanent magnets , at least two optics units, an ejection unit and a main frame. [0011] The present invention addresses the formation of hysteresis loops of both permanent magnet and the temporary magnet due to retentivity. The retentivity of the permanent magnet is addressed by designing and deploying a specialized material in the permanent magnet whose retentivity is brought back to zero after de-magnetisation by applying an external coercive force for effective handling and/or grading of smaller sized objects. The invention also discloses designing and deployment of a specialized material in the core of the temporary magnet which is having negligible retentivity and such negligible retentivity is also minimized by applying an external coercive force after de¬magnetisation along with high magnetic flux density during magnetisation for maintaining higher saturation point of magnetic flux for accurate ejection of smaller sized objects. The retentivity of the permanent magnet is brought back tozero for effective

handling and/or grading of smaller sized objects. The grading machine of the present invention and the method for grading smaller sized objects deals mainly with the smaller sized objects having size range of at least in between 2mm to 25mm, the examination beds are structurally exactly same to the grading machine of prior art of Indian Application No. 994/CHE/2014, but in the present invention, as the smaller sized objects are been considered thus the size of the examination bed with embedded permanent magnet is also reduced in proportionate to the required magnetic flux density for providing an improved way of smaller sized object holding/handling, conveying and ejecting such smaller sized objects in an efficient manner by addressing the concern of hysteresis loop and by resolving the concern of hysteresis loop while dealing with magnetism in order to generate appropriate, required amount of magnetic flux density for efficient overall holding/handling, conveying and ejecting of smaller sized objects for high performance grading.
[0012] In accordance with one aspect of the invention, disclosed is a method for grading smaller sized objects into multiple grades in a single pass based on at least one external and/or internal parameters. The method provides quality grading due to multiple continuous cycles of magnetisation and de-magnetisation of temporary and permanent magnets in order to eject objects of smaller sized according to their respective ‘defined grade data’, thereby grading smaller sized objects into multiple grades in a single pass of the conveyor by efficient holding, conveying and ejecting of each object present in respective examination beds into plurality of pre-determined grade containers of the ejection unit.
[0013] Accordingly, few objects of the present invention are listed below: • The main object of the present invention is to provide a grading machine for grading typically smaller sized objects to ensure efficiency and high performance of the machine

for grading any smaller object into multiple grades in a single pass based on at least one
external and/or internal parameters using multi-vision analysis of each smaller sized
object individually by capturing multiple images of each object in three dimensional
space for high quality grading.
It is another object of the present invention to provide a grading machine to provide
efficient grading by using dampers (shock absorbers) having desired property to absorb or
damp minute vibrations occurring in the tray due to interlinking via chain link but not
limited to chain links during conveying of objects on conveyor as even very minute
vibrations in amount also contribute to performance of the machine.
It is still another object of the present invention to provide a grading machine having an
examination bed of pre-determined size with embedded permanent magnet in it which is
capable of carrying an object having smaller size ranging from at least 2mm to 25mm
with higher flux density while conveying the smaller sized objects.
It is a further object of the present invention to provide a grading machine which
comprises a pre-defined sized permanent magnet associated with each examination bed
and has a significant property of closing the hysteresis loop created by the permanent
magnet in order to eliminate its effect on the corresponding magnetic flux density during
magnetisation and de-magnetisation.
It is still further object of the present invention to provide a specialized material for
permanent magnet affixed in each examination bed in order to generate required amount
of magnetic flux density according to the pre-determined size of permanent magnet so
that each examination bed adheres to the conveyor for efficient holding, conveying and
for ejecting of smaller objects for efficient throughput of the grading machine.
It is another object of the present invention to provide a grading machine which operates
by using an electronically effective temporary magnet which has a specific material for

core of a temporary magnet which has a significant property of closing the hysteresis loop created by the temporary magnet in order to eliminate its effect on the corresponding magnetic flux density during magnetisation and de-magnetisation to facilitate in generating appropriate amount of flux density to actuate the permanent magnet associated with each examination bed for accurate ejection of each object in respective grade container, thereby avoiding dropping of objects outside/away from the grade container. It is still another object of the present invention to provide a grading machine which ensures efficiency and high performance due to synchronized feeding, reduced vibrations and appropriate flux density generation for firm holding of each smaller object, smooth conveying and accurate ejection of such firmly held object during ejection into respective grade container in a time-efficient manner.
It is a further object of the present invention to provide an accurate and efficient method which is an on-line method for grading any smaller object into multiple grades in a single pass based on predefined external/morphological or internal parameters after analyzing smaller sized objects individually on object by object basis, providing a rapid and time-efficient method of grading each smaller sized object groundnuts unlike existing grading systems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] For a better understanding of the invention, reference is taken to the accompanying exemplary drawings listed below:
FIG. 1 is a standard graph illustrating behaviour of the magnetic flux density with the changing values of applied magnetic force and the formation of hysteresis loop in the permanent magnet embedded inside each examination bed according to the grading machine of the prior art.

FIG.2 is a graph illustrating behaviour of lower saturation point of the magnetic flux
density with the changing values of applied magnetic force in the electromagnet coil
placed inside ejection unit according to the prior art.
FIG. 3 is a schematic diagram illustrating the arrangement of non-limiting elements of a
grading machine for grading smaller sized objects according to one embodiment of the
present invention.
FIG. 4 is a schematic diagram illustrating a plurality of dampers fitted at pre-determined
distance underneath of endless rotating medium according to one embodiment of the
present invention.
FIG. 5 (a) is a schematic diagram illustrating objects placed in examination beds of one
tray of the grading machine according to one embodiment of the present invention.
FIG. 5 (b) is a schematic diagram illustrating structural (internal and external)
arrangement of a single examination bed according to one embodiment of the present
invention.
FIG. 6 is a graph illustrating behaviour of the magnetic flux density with the changing
values of applied magnetic force in the electromagnet coil placed inside ejection unit
according to the present invention.
FIG. 7 is a graph illustrating the relationship between the magnetic flux density and the
surface area of the permanent magnet embedded in each examination bed according to the
present invention.
FIG. 8 is a graph illustrating the relationship between the magnetic flux and the surface
area of the permanent magnet embedded in each examination bed according to the present
invention.

FIG. 9 is a graph illustrating the comparative behaviour of hysteresis loop when hard
magnet and soft magnet is used in the material of core of electromagnet according to the
present invention.
FIG. 10 is a diagram illustrating magnetised (10a) and demagnetised (10b) states of
temporary magnet according to the present invention.
FIG. 11 is a flow chart depicting a method for grading smaller sized objects by using a
grading machine according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[0015] A detailed description of one or more embodiments of the invention is provided below along with accompanying figures that illustrate the principles of the invention. As such this detailed description illustrates the invention by way of example and not by way of limitation.
As used herein, the term ‘object’ shall refer to any ‘homogeneous’ or ‘non-homogeneous’ object which may be naturally occurring or synthetically manufactured object of different external and/or internal parameters. The term ‘object’ shall refer to naturally occurring product including but not limited to any agricultural products including, but not limited to any legumes, groundnuts, lentils, nuts, pulses, beans, tree nuts, or any other similar objects, which may be ‘wet’ or ‘dried’ or ‘whole’ or ‘broken’ or ‘split’ or ‘mature’ or ‘immature’ or combination or mixtures of different forms of objects. The term ‘object’ shall also refer to synthetically manufactured products like, pebbles, gems, etc. sizing in the range of at least 2mm to 25mm.
As used herein, the term ‘object’ and ‘smaller sized object’ are used interchangeably and both the terms carry same meaning for the purposes of the inventionAs used herein, the term ‘pre-determined area’ shall refer to the specific area of the examination bed in which pre-determined size of permanent magnet is embedded/fixed.
As used herein, the term ‘external parameter’ shall refer to any morphological, extrinsic features related to any smaller sized object, which may include but not limited to size, shape, color, surface properties, profile, kernel profile or alike any other properties, defects, mechanical injuries, or any other possible properties. As used herein, the term ‘internal parameter’ shall refer to any intrinsic features which may include but not limited to moisture content, rancidity level, oil content, maturity level, any microbial infection or

any microbial activity or biochemical activity inside smaller sized object which make the object/agricultural product rotten, infected or diseased, or any other possible properties. As used herein, the term ‘optics unit’ shall refer to a programmable plurality of cameras along with plurality of light sources, an image processor unit, and a first storage module.; cameras can be ‘regular color cameras’ or ‘multi-spectral cameras’. The term ‘multi-spectral cameras’ work at different frequencies of electromagnetic spectrum (multi-spectrum) including but not limited to visible, ultra-violet, an infra-red, an x-ray, a laser ray for enhanced analysis of the smaller sized objects based on external and/or internal parameters of any other object of interest. The optic unit does not necessarily include camera, but it may also includes one of an ultra-violet unit, an infra-red unit, an x-ray unit or a laser ray unit that releases appropriate rays for examining at least one internal and/or external or any other possible characteristics and a processor unit that processes the appropriate rays for determining grade of the smaller sized object under examination and use of cameras and image processor unit as described in this invention does not limiting the scope of examination of object. Any above mentioned examination unit or processes that can determine at least one internal and/or external or any other possible characteristics of any smaller sized object under examination shall be considered within the scope of the present invention.
As used herein, the term ‘defined grade-data’ shall refer to a ‘defined grade of each object’ determined by the controller related to different grades based on comparison of different internal and/or external or any other parameters (‘pre-determined grade parameters’) stored in secondary storage module of the controller with real time different internal and/or external or any other parameters (‘grade parameters’) sent to the controller by first storage module of one/plurality of cameras or by any other image processing means using any appropriate rays of the electromagnetic spectrum.

[0016] In one embodiment, the present invention discloses a grading machine for grading smaller sized objects into multiple grades in a single pass based on its internal and/or external parameters, specifically illustrated for groundnut (peanut) which needs proper handling while analyzing and performing various operations during grading by addressing difficulty of handling such smaller sized object during holding, conveying, analyzing and ejecting of such object. For instance, groundnut or peanut, show different external variations like size, shape, color, surface properties etc due to its extensive variations in size, shape like small, big and color including dark pink, light pink, light red etc, but groundnuts show equally extensive variations in case of internal variations under different situations like oil content, easy vulnerability of groundnuts to internal biochemical changes/contamination or microbial infections, especially mold fungus during growth and poor storage conditions which may lead to affecting the kernel quality at disastrous extent. Therefore, smaller sized objects need more attention for holding such object firmly while analyzing such variations of each object individually by conveying which is possible only when such smaller sized objects are handled during each step of grading viz. holding/handling, conveying and ejection for maintaining accuracy in quality grading.
[0017] The present invention is described for a grading machine and a method for grading smaller objects into multiple grades in a single pass based on its external and/or internal parameters by achieving required magnetic flux for performing many steps in the grading machine while grading such smaller sized objects. Although, the present invention is specifically illustrated for groundnut, the present invention is not limited only for grading groundnut in the grading machine, in fact any type of smaller sized objects are graded in the grading machine. The components used for grading objects, typically

smaller sized objects in grading machine and steps of grading such smaller sized objects , by using the grading machine are described in the following description. [0018] Referring to FIG. 3 and FIG. 11, it is a schematic perspective view illustrating a grading machine 100 according to one embodiment of the present invention. The non-limiting components of the grading machine for grading smaller sized objects (not illustrated in Figures) mainly are at least one controller 10 (typically a master controller, not shown in any Figures) , an object introducing unit (20), an in-feed unit (30), a singulator (40), a plurality of multi-vision examination beds (50), at least one conveyor (60) having a endless rotating medium (65), a plurality of dampers (70), a plurality of permanent magnet (80), at least two optics units (90a and 90b), and an ejection unit (120). In one embodiment, the components of the grading machine (100) are disposed on at least one frame (150).
[0019] Referring to FIG. 3 to 11, the details of the present invention are described hereinafter, In one embodiment, the controller (10) is one master controller. The controller (10) is fed with predetermined feed rate of the object, ‘pre-determined area of the examination bed’, ‘pre-determined grade parameters’ (pre-determined external and/or internal parameters), ‘pre-determined size of a permanent magnet’, ‘pre-determined grade container parameter’ in a second storage module (12) of the controller (10). [0020] In another embodiment, the controller (10) may be more than one controller. Smaller sized objects are introduced in object introducing unit (20) which is configured to receive objects and objects fall into the object introducing unit (20) due to gravity. The objects introducing unit (20) is a hopper arrangement that distributes the load evenly to the machine to the in-feed unit (30) which is connected with the object introducing unit (20) to receive objects at controlled feed rate. The feed rate is controlled/determined by the controller (10) based on the input received from feed sensors (32). The controlled feed
14

rate is the rate at which the objects are desired to move in the in-feed unit (30). The in-feed unit (30) further comprises with at least one feed sensor (32) placed in the vicinity of the in-feed unit (30), which senses the feed rate of the objects moving from the in-feed unit (30). The sensors (32) send the feed rate signal to a feed controller (not illustrated in Figures) which in-turn is controlled by the controller 10. The controller 10 directs the feed controller that further directs the in-feed unit (30) to increase the feed rate, decrease the feed rate or maintain the feed rate based on the real-time input received from feed sensors (32). Thus, due to controlled feed rate, the objects are directed further from the in-feed unit (30) in at least one queue. Additionally, in one embodiment the grading machine includes a slider and at least one set of vibrators cooperating with the slider for receiving objects at a pre-determined feed rate, wherein each set comprises at least two vibrators, out of which one vibrator is inverted vibrator thereby configured to direct objects in at least one queue.
[0021] The singulator (40) is connected with the in-feed unit for singulating objects by picking objects from the at least one queue and synchronously placing it on the examination beds (50), such that each examination bed has one object. In an exemplary embodiment the singulator (40) is pick and place unit including a rotating vacuum drum, with a plurality of holes configured thereon. Due to vacuum zone created in it, each hole picks one object from the queue and places each picked object on one examination bed which has pre-determined bed area. The dropping of object(s) is due to the objects are singularly picked up due to Bernoulli and partial vacuum force generation near the surface of the rotating vacuum drum of the singulator (40). In another embodiment the singulator (40) is a pick and place unit which includes a suction pad for picking and placing objects on the examination bed (50). Although, the singulator (40) of the present invention describes singulating objects by the pick and place mechanism, however, the

present disclosure is not limited to the pick and place mechanism and any mechanism that can singulate the objects can be used.
[0022] There is plurality of examination beds (50) which receives singulated objects. These plurality of examination beds (50) are arranged adjacent to each other to form a single tray. Each tray having examination beds (60) is interlinked with other tray to form plurality of trays and such plurality of trays are interlinked together via a endless rotating medium (65) and such plurality of inter-linked trays make the endless conveyor (60) as illustrated in FIG. 4 and 5. Each tray is linked on the chain link (65) with the help of tray mounting fasteners. The conveyor (60) is having a endless rotating medium (65) which is a chain link (65). The conveyor (60) is configured to move objects placed in examination beds (50) from a first place (60a) to a second place (60b). The first place (60a) is a place where singulated objects are placed in the plurality of examination beds of the conveyor (60) and the second place (60b) is a place where objects are ejected from the machine to get collected in the respective pre-determined grade containers (126). In one embodiment, the plurality of examination beds (50) is mounted on the conveyor (60). In another embodiment, the examination bed is in-built in the conveyor (60). [0023] Referring to FIG. 4, which is a schematic diagram illustrating a plurality of dampers (70) which are fitted at pre-determined distance underneath of the chain link (65) and in contact with the chain link (65) in between the first place (60a) and the second place (60b) of the conveyor (60). The lower part (61) of conveyor (60) consists of ‘n’ number of dampers (70) in order to prevent vibrations below the conveyor (60). The dampers (70) are specifically meant for damping/absorbing/controlling shock/vibrations generated during receiving, conveying and ejecting objects placed in examination beds (50) of the grading machine as very minute vibrations can also affect holding /conveying

or ejecting capacities of the grading machine, especially when the object to be graded is a small object like groundnut, resulting into poor efficiency of grading operation. [0024] Referring to FIG. 5 (a) which is a schematic diagram illustrating objects placed in examination beds of one tray (55). The tray (55) is having plurality of examination beds which are arranged adjacent to each other to make a tray (55). Each examination bed (50) is accommodated with a single object (15). Each examination bed (50) is made typically of optical material, typically, of transparent material. The transparent material is at least one of acrylic material or glass material. Each examination bed (50) is transparent for enabling the multi-vision analysis of the object for examination which is placed in it. The examination bed (50) is fitted and detachable from the conveyor (60). Typically, the examination bed (50) is a single unit. Alternatively, each examination bed (50) has a plurality of compartments (51).
[0025] Each examination bed (50) is separated from another examination bed (50) through one compartment (51) and configured to receive one object (15). In one embodiment, each examination bed (50) is in-built or embedded in the conveyor (60). In another embodiment, the examination bed (50) is mounted on the conveyor (60) and move along with the conveyor. The pre-determined size of permanent magnet (80) is embedded in each examination bed (50) of pre-determined area. [0026] Referring to FIG. 5 (a), each examination bed (50) of the tray (55) is capable of holding one smaller sized object (15). The number of electromagnetic coils present inside the ejection unit (120) is equal to the number of examination beds (50), so that each examination bed (50) will be ejected by a separate electromagnetic coil of the temporary magnet according to the ‘defined grade data’ of the objects.
[0027] Referring to FIG. 5 (b) which is a schematic diagram illustrating structural (internal and/or external) arrangement of a single examination bed (50). The present

invention provides increased number of examination beds (50) per tray (55) due to reduction in bed area of each examination bed (50). Each examination bed (50) is embedded with/associated with a pre-determined size of permanent magnet (80) in it which is meant for adhering the examination bed to the tray (55) via a touch plate (Not shown in any FIG.). The touch plate is a part of the tray (55) which is magnetic in nature for each examination bed (50) of the tray (55) to be held in the tray (55). A magnetic clip (52) is provided for enclosing the examination beds (50) of the tray (55). The tray (55) is linked on the chain link (65) with the help of tray (55) mounting fasteners. Examination beds (50) are fixed on the tray (55) at one side through examination bed hole (53) for axis rod (Not shown in any FIG.). The axis rod is a part of one tray (55). The visible area (54) of the examination bed (50) normally opens automatically without being physically touched by any means and open-able normal to the motion of the conveyor (60). Each permanent magnet (80) is made of such a material in which hysteresis loop caused due to retentivity is closed by using an external force immediately after each de-magnetisation in order to generate maximum magnetic flux density proportionate to the pre-determined area of the examination bed (50) during magnetisation for every proper ejection of each examination bed (50)
[0028] The examination beds (50) are thenafter exposed to at least two optics units (90a and 90b). Each examination bed (50) is transparent for enabling multi-vision analysis of the object by at least two optics units (90a and 90b). In one embodiment, the grading machine (100) comprises at least two optics units (90a and 90b). Out of two optics units (90a and 90b), at least one top optics unit (90a) is disposed proximally above the examination bed (50) or conveyor (60) and at least one bottom optics units (90b) is disposed proximally above and below examination bed (50) or conveyor (60) respectively for examination of each object (15).
18

[0029] Each optics unit (90) includes a plurality of cameras (92), a plurality of light sources (94), an image processor unit (96), and a first storage module (98). The plurality of cameras are configured to capture real time one/multiple images of each object (15) under examination in three dimensional space from different views and different angles for further determining at least one external and/or internal parameters of each object (15) under examination. The captured image is without reconstructing the image of the object (15), this feature helps in accurate and quick analysis of each object (15) under examination. The plurality of light sources (94) enables the cameras for clear/focused capturing of each object under examination. The image processor unit (96) processes each captured one/multiple images of each object into at least one ‘parameter’ based on internal and/or an external parameter of each object under examination also referred as ‘grade parameters’ for the purposes of the invention.
[0030] The first storage module (98) is configured to store each ‘grade parameter’ generated in the image processor unit (96).
[0031] The controller (10) includes a grading comparator (110) and a second storage module (12). The grading comparator (110) which compares each ‘grade parameter’ stored in the first storage module (98) with ‘pre-determined grade parameters’ stored in the second storage module (12), wherein the ‘pre-determined grade parameter’ is a standard parameter set by a regulatory authority which determines the grade of the object, and provides a ‘defined grade data’ for each object under examination. The grade containers (126) are categorized according to the size, shape, color, and any other characteristics of the objects which can be an internal and/or an external parameter of any other parameter.
[0032] The controller (10) decides the ‘defined grade data’ for each object and location of each object of each examination bed (50). The grading machine (100) includes the

ejection unit (120), it is an electromagnetic enclosure which is mounted above/in proximity with the conveyor (60) and includes a plurality of ejector controller (122), a plurality of temporary magnets (124). Each temporary magnet (124) is an electronically effective temporary magnet (124)/ electromagnet. The temporary magnet (124) includes an electromagnetic coil wound around a core.
[0033] In an operative magnetised configuration, the controller (10) receives the ‘grade parameters’ of the object(s), under examination, when each object is disposed on each examination bed with respective permanent magnet. The controller (10) determines and remembers the location of each object of ‘defined grade data’ of each examination bed (50) while conveying. The controller determines the location of the respective ‘pre¬determined grade container’ (126) into which each object of ‘defined grade data’ should be dropped. When the examination bed(s) with respective permanent magnet(s) reaches at pre-determined desired grade location(s) on said conveyor (60), the respective temporary magnet(s) of ejection unit (120) coincide with respective permanent magnet(s) (80) of respective examination bed(s). At that point the controller (10) signals respective ejector controller (122) for magnetising temporary magnets (124). The magnetic field is generated between respective temporary magnets (124) and respective permanent magnet (80). Each electromagnetic coil of each temporary magnet (124) repel the permanent magnet (80) of one examination bed, then after respective examination beds (50) are opened. The object(s) from respective examination bed (50) are directed towards proximal ‘pre-determined grade containers’ (126) to eject respective grades of object of ‘defined grade data’ into respective ‘pre-determined grade container’ (126). In an operative de-magnetised configuration, after ejecting each object from respective examination bed, the controller (10) signals the respective ejector controller (122) for

restricting the flow of current in respective temporary magnet(s) (124) in order to make the temporary magnet (124 de-magnetised.
[0034] Referring to FIG. 6, the graph illustrates the behaviour of the magnetic flux density (represented by ‘B’) with the changing values of applied magnetic force (represented by ‘H’) in the electromagnetic coil placed inside ejection unit (120). It illustrates the generation of the maximum flux density (‘B’) up to the highest saturation point (represented by ‘H’) by deploying an electronically effective temporary magnet in which the material of the core of the temporary magnet (124) with all the domains of the material become unaligned as soon as the magnetic force (‘H’) is removed, making the material completely de-magnetised enabling proper holding, proper conveying and proper ejection of the objects of ‘defined grade data’ accurately into the ‘pre-determined grade containers’ (126) by using ‘non-contact ejection mechanism’, and not outside the ‘pre¬determined grade containers’ (126), wherein the number of temporary magnets (124) is equal to the number of examination bed (50) for the purpose of ejection of different grades of objects (15) into the plurality of ‘pre-determined grade containers’ (126) which are disposed proximal to said second place of conveyor (which is ejection point of each object). The entire opening and closing mechanism of each examination bed (50) is electronically controlled non-contact mechanism which is automated, controlled and synchronous which occurs while the conveyor (60) is in motion. [0035] Referring to FIG.7 it is a graph depicts the relationship between the magnetic flux density (B) and the surface area (A) of the permanent magnet (80) embedded in each examination bed (50) which shows that the increased magnetic flux density means smaller surface area which is required to deal with smaller sized objects for effective handling of smaller sized objects (15).

[0036] Referring to FIG. 8 which is a graphical representation depicting the relationship between the magnetic flux and the surface area of the permanent magnet embedded in each examination bed. As we know B= Φ/A
Where B represents Magnetic Flux Density ‘Φ’ represents ‘Magnetic Flux’ and ‘A’ represents ‘area of cross section’ Ideally in order to increase the magnetic flux density, the surface area has to be decreased while keeping the magnetic flux constant. But, as there exists exponential relation between the surface area of cross section and the magnetic flux, the magnetic flux cannot remain constant with the changing values of surface area A. Further, in order to get maximum magnetic flux density, Where,
Φ = F / R
F = Magnetomotive force and R representing reluctance Now as P = 1/R, the inverse of Reluctance is called Permeance. B= Φ/A = F/RA
= FP/A as P = µ(Ag Lm/AmLg)k
Where Ag, = the air-gap area and Am = the magnet pole area,
Lg = the air-gap length and Lm = the magnet length and µ is the Permeability of material.
B= [F µk (Ag Lm/AmLg)]/Am
As k(Ag Lm/AmLg) is constant by maximising the values of F & µ for a given application would result in high flux density.

[0037] Accordingly, in the present invention, the surface area of the permanent magnet embedded in the examination bed (50) has been reduced to accommodate smaller sized objects (15) in each examination bed (50) so as to increase the magnetic flux density, but at the same time by keeping the magnetic flux constant, which provides accurate ejection of objects (15) while grading smaller sized objects efficiently. The material used for the designing of the permanent magnet (80) includes, but not limited to rare earth metals like ferrite, neodymium, samarium-chromium Terfenol-D magnets. Due to the pre-determined size of the material deployed in the permanent magnet (80) of each pre-determined examination bed (50), after de-magnetisation by the ejector controller (122), the retentivity of the smaller sized permanent magnet (80) is also removed by some external coercive force in order to close its broad hysteresis loop. Therefore, respective examination beds (50) are ejected each time with maximum magnetic flux density by immediately bringing back retentivity of permanent magnet(s) (80) to zero and by minimizing the retentivity of the temporary magnet by an external coercive force after every de-magnetisation.
[0038] Further, referring to FIG. 9 which is a graph illustrating the comparative behaviour of hysteresis loop when the hard magnet (represented by ‘H’) and the soft magnet (represented by ‘S’) used in the core of the temporary magnet (124). The present invention discloses the design and the deployment of soft material in the core of the temporary magnet (124). The soft core material has many properties which are required for quick de-magnetisation. The core material has high saturation magnetisation, low coercivity and retentivity, and high permeability. The material which is having these properties is called soft magnetic material which can be easily magnetised and de¬magnetised to provide a narrow hysteresis loop, as low saturation magnetisation, high coercivity and retentivity leads to broad hysteresis loop which affect smooth ejection of

each object during grading cycle. Soft magnetic material has been used for this purpose in order to lower the chances of hysteresis loss to achieve a very narrow hysteresis loop after each de-magnetisation which does not affect the process of magnetisation and de¬magnetisation all of which overcome the disadvantages of the inventions mentioned in the prior art.
[0039] Referring to FIG. 10, the behaviour of hysteresis loop when soft magnetic material is used in the core of temporary magnet/electromagnet (124) as compared to the one where hard magnetic material is used. The soft magnets (temporary magnets) used in the core of the electromagnet provides a narrow loop and the hard magnets (permanent magnets) provides the broad hysteresis loop. The material which is deployed as the soft magnetic material in the core of the electromagnet includes, but not limited to a rare earth material, which are targeted to maximize the magnetic flux density in a pre-determined given bed area of operation wherein the magnetic domains are enhanced such that the area of magnetic flux linkage is maximized.
[0040] Referring to FIG. 10, the temporary magnet (124) are soft magnetic materials which are deployed in the core of the electromagnet for the purposes of the present invention. The domains of soft temporary magnet (124) gets back to random pattern as soon as the magnetic field is removed (de-magetised state) because of their low retentivity. Soft magnetic materials are shown to be with lined up orientation of domains in magnetised state (10a) and random orientation of domains in de-magnetised state (10b). The core is having such a property that it has negligible retentivity thus it gets de¬magnetised as soon as the magnetic force is removed due to which the core forms a narrow hysteresis loop, but such narrow hysteresis loop can also impact the magnetisation/de-magnetisation of the temporary magnet (124) over the cycles of magnetisation and de-magnetisation of each temporary magnet (124), therefore such

negligible retentivity is also minimized significantly by applying some external coercive force, so that such temporary magnet (124) gets de-magnetised completely and immediately as soon as the magnetic force is removed without affecting further magnetisation of the temporary magnet (124) in next cycle of magnetisation and de-magnetisation so as to generate maximum flux density during magnetised configuration. The grading machine provides increased throughput, thereby grading smaller sized objects (15) into multiple grades a single pass time-efficiently by proper holding/handling and ejecting smaller sized objects (15) during grading operation. [0041] The present invention also describes the method for grading smaller sized objects (15) by using a grading machine (100) according to one embodiment of the present invention. Referring to FIG. 11 which represents the method flowchart, the method include feeding a controller (10) with predetermined feed rate of the object, pre¬determined grade parameters, pre-determined area of the examination bed, pre-determined size of a permanent magnet (80), magnetic flux density, pre-determined grade container parameter and pre-determined grade parameters, in a second storage module (12) of the controller (10). In one embodiment feeding the feed rate to the controller (10), such feed rate is controlled by the controller (10). In another embodiment, feeding controlled feed rate to the feeding controller controlled by the controller (10). The feed rate of the objects (15) into the in-feed unit (30) depends upon real time inputs of the feed sensor received by the controller (10). A endless conveyor (60) is actuated to rotate from first place to second place by a rotating medium having plurality of dampers at pre¬determined distance underneath of the endless rotating medium for damping/absorbing/controlling shock/vibrations generated during receiving, conveying and ejecting objects (15) in the grading machine.

[0042] The objects (15) are introduced in an object introducing unit (20) for receiving objects (15). After receiving objects (15) from the object introducing unit (20), objects (15) are fed through an in-feed unit (30) with controlled feed rate of objects (15) due to such controlled feeding, objects (15) move further in at least one queue. The objects (15) received from the queue are singulated in the singulator (40).
[0043] In one embodiment of the present invention, the step of singulating objects (15) includes picking and placing at least one object by rotating an outer vacuum rotating drum configured with a plurality of holes, proximal to the object(s), and an inner heavy, cylindrical, solid roller coated with a soft material. The inner roller rotates inside the rotating drum in a non-concentric axis, such that each hole picks at least one object from the queue. Again after picking objects (15), the outer rotating drum rotates and causes the picked objects (15) to fall therefrom and get placed on the examination bed (50). [0044] In another embodiment of the present invention, the step of singulating objects (15) includes picking and placing at least one object by rotating a vacuum rotating drum configured with a suction pad. The suction pad which is proximal to the object(s) is actuated to pick objects (15). The vacuum rotating drum is rotated. Once the objects (15) are picked by the suction pad, further there is de-actuating suction so that the picked objects (15) fall from the suction pad and get placed in the examination bed such that each examination bed receives a single object.
[0045] At least one singulated objects (15) are disposed respectively on at least one examination bed (50) of the conveyor (60), wherein each examination bed (50) is of a per-determined is having embedded permanent magnet (80) in it and each examination bed moves with the conveyor (60) having endless rotating medium. Objects (15) are disposed on the examination beds (50) and are exposed to the optics unit (90). Examination of each object disposed on each examination bed (60) with embedded

permanent magnet (80) is carried out by a plurality of cameras (92) and light sources (94) of at least two optics units positioned above and below examination bed (50) by capturing real-time multiple images of each object in three dimensional space. Multiple images of each object disposed on each examination bed (50) is processed by an image processor unit (96) of at least two optics units (90a and 90b), wherein multiple images are processed into at least one parameter. Each parameter is stored in a first storage module of said optic unit (90). Each parameter stored in the first storage module (98) is compared with a pre¬determined grade parameter stored in a second storage module (12) by using a grading comparator (110). The second storage module (12) and the grading comparator (110) are configured in the controller (10). The controller (10) determines the grade of object(s) disposed on each examination bed (50) with embedded permanent magnet (80) to provide a ‘defined grade data’. The controller also locates the ‘pre-determined grade containers’ (126) based on the ‘defined grade of objects (15)’ disposed on each examination bed (50) with embedded permanent magnet (80).
[0046] The controller intelligently remembers the location of each object of ‘defined grade data’ while conveying on said conveyor (60). The controller signals an ejector controller (122) when object (15) disposed on each examination bed (50) with embedded permanent magnet (80) reaches a pre-determined location on the conveyor (60), when each respective temporary magnet (124) coincide with each respective permanent magnets (80) of respective examination bed (50). The current flows in respective temporary magnets (124) to actuate respective temporary magnets (124) as defined by the ejector controller (122). Due to pre-determined bed area of each permanent magnet (80), appropriate magnetic flux density is generated in between the respective temporary magnets (124) and the respective permanent magnets (80) with pre-determined bed area so that there is required repulsion of respective permanent magnets (80) of each

examination bed (50) which are proximal to respective grade containers (126). The temporary magnet (124) includes an electromagnetic coil wound around a core made of material having negligible retentivity which is brought back equal to zero/minimized by closing narrow hysteresis loop by applying external coercive force. The objects (15) are ejected from respective examination beds to get collected in pre-determined grade container (126).
[0047] Thenafter, respective temporary magnets (124) are de-actuated to demagnetize respective permanent magnet (80) such that the temporary magnets (124) whose retentivity is though negligible, is minimized by an external coercive forces gets de-magnetised completely. Thereafter respective examination beds are closed. The permanent magnets (124) also gets de-magnetised by the respective temporary magnet (124), and the retentivity of the permanent magnet (80) is brought back to zero by applying external coercive force due to deployment of a specialized material thereby closeing the hysteresis loop created by respective permanent magnets (80) proportionate to the pre-determined area of the examination bed (50). The grading machine effectively grades smaller sized objects (15) in multiple grades in a single pass of conveyor based on at least one external and/or internal parameters (‘defined grade parameter’) in an automated, controlled and synchronous manner with said conveyor (60) by proper holding/handling and ejecting of smaller sized objects (15) by maintaining required magnetic flux density according to the smaller pre-determined bed area of each examination bed for effective grading
[0048] The description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations and alternatives and uses of the invention, including what we presently believe is the best mode for carrying out the invention. It is to be clearly understood that routine variations and

adaptations can be made to the invention as described, and such variations and adaptations squarely fall within the spirit and scope of the invention.

What is claimed is:
1) A grading machine (100) for grading smaller sized objects (15), said machine comprising:
• at least one controller (10);
• at least one object introducing unit (20) configured to receive smaller sized objects (15) of different external and /or internal parameters;
• at least one in-feed unit (30) connected with said object introducing unit and configured to receive objects (15) at a controlled feed rate, wherein the feed rate is determined by said controller (10) based on the input received from feed sensors (32) provided in said in-feed unit (30), said in-feed unit (30) further configured to direct objects (15) in at least one queue;
• at least one singulator (40) synchronously cooperating with said in-feed unit (30) and configured to singulate objects (15) received from the queue;
• a plurality of examination beds (50), wherein each examination bed (50) is configured to receive one singulated object (15) from said singulator (40), said each examination bed (50) has a pre-determined bed area;
• at least one conveyor (60) having a endless rotating medium (65) configured to move object from a first place (60a) to a second place (60b), configured to receive said singulated objects (15), said examination beds (50) are configured to move along with said conveyor (60);
• a plurality of dampers (70) fitted at pre-determined distance underneath of said endless rotating medium and in contact with said endless rotating medium in between said first place (60a) and said second place (60b) for damping/absorbing/controlling shock/vibrations generated during receiving, conveying and ejecting objects (15) in the grading machine;

• a plurality of permanent magnet (80), wherein each permanent magnet (80) is of pre-determined size and embedded to each examination bed (50), wherein each said permanent magnet (80) is made of such material in which hysteresis loop caused due to retentivity is closed by using external force immediately after each de-magnetisation of each permanent magnet (80 of each examination bed (50) to generate maximum magnetic flux density proportionate to the pre-determined area of the examination bed (50);
• at least two optics units (90a and 90b) comprises of at least one top optics unit (90a) and at least one bottom optics units (90b), wherein said top optics unit (90a) and said bottom optics unit (90b) is disposed proximally above and below said examination bed (50) respectively for examination of each object (15), and said each optics unit (90a and 90b) comprises:
o a plurality of cameras (92) disposed proximal to said examination beds (50) and configured to capture multi-angled real time one/multiple images of each object under examination in three dimensional space for further determining at least one internal and/or external ‘grade parameter’ of each object under examination;
o a plurality of light sources (94) for enabling said cameras for clear/focused capturing of each object under examination;
o an image processor unit (96) for processing said captured one/multiple images of each object (15) into at least one ‘grade parameter’; and
o a first storage module (98) configured to store each said ‘grade parameter’;
• a grading comparator (110), configured in said controller (10) to compare each said grade
parameter stored in said first storage module (98) with a ‘pre-determined grade
parameters’ stored in a second storage module (12) of said controller (10) and provides a
‘defined grade data’’ for each object (15) under examination, and location of each object
(15) of ‘defined’ grade data’ of each examination bed (50);

• at least one ejection unit (120) is mounted on said conveyor and comprises an electromagnetic enclosures having:
o a plurality of ejector controller (122);
o a plurality of temporary magnet (124), wherein each temporary magnet (124) includes an electromagnetic coil wound around a core, wherein material of said core has negligible retentivity, due to which maximum flux density is generated during magnetised configuration, and said material gets magnetised and demagnetised immediately with the formation of narrow hysteresis loop, wherein the narrow hysteresis loop is also closed by applying external coercive force for minimizing said negligible retentivity; and
o a plurality of pre-determined grade container (126) disposed proximal to said second place, wherein each container is configured to receive object of ‘defined grade data’; wherein,
in an operative magnetised configuration said controller (10) after receiving the said ’grade parameters’ of said objects (15), under examination, when each object is disposed on each examination bed (50) with respective permanent magnet (80), said controller (10) determines and remembers the location of each said object of ‘defined grade data’ of said examination bed while conveying, and said controller (10) determines the location of the respective ‘pre-determined grade container’, when said examination bed reaches at pre¬determined desired location on said conveyor (60) where, said respective temporary magnets (124) coincide with each said respective permanent magnets (80) of respective examination bed (50); said controller (10) signals said respective ejector controller (122) for permitting flow of current in respective temporary magnets (124) such that a magnetic field is generated between said temporary magnets (124) and said permanent magnets (80), repel said permanent magnet (80) of each examination bed to open respective examination beds (50), direct said objects (15) of ‘defined grade data’ proximal to said

grade container (126) and eject said objects (15) of ‘defined grade data’ in said grade containers (126) to get collected therein,
wherein, in an operative de-magnetised configuration said controller (10) signals said respective ejector controller (122) for restricting flow of current in respective temporary magnets (124) such that said temporary magnets (124) gets completely de-magnetised having negligible retentivity therewithin, said respective temporary magnets (124) demagnetizes said respective permanent magnets (80), wherein negligible retentivity of said temporary magnet (124) is minimized and retentivity of said permanent magnet is removed completely (80) and immediately for closing narrow hysteresis loop and broad hysteresis loop respectively thereof by applying external coercive force for creating maximum flux density during magnetisation so that said examination beds (50) are ejected each time with maximum, but constant and controlled magnetic flux density in proportionate to said pre-determined area of examination bed (50); and thereby, enabling grading of said small sized objects (15) of ‘defined grade data’ in multiple grades in a single pass of said conveyor (60) in an automated, controlled and synchronous manner with said conveyor (60).
2) The grading machine as claimed in claim 1, wherein said in-feed unit (30) includes:
• a slider; and
• at least one set of vibrators cooperating with said slider for receiving objects (15) at a pre¬determined feed rate, wherein each set comprises at least two vibrators, out of which one vibrator is inverted vibrator thereby configured to direct objects (15) in said queue.
3) The grading machine as claimed in claim 1, wherein said feed rate of objects (15) in-feed
unit (30) is controlled by a feed controller which is controlled by said controller (10) and
is individually regulated by the controller (10) to maximize the feeding efficiency.

4) The grading machine as claimed in claim 1, wherein said singulator (40) is a pick and place unit which comprises an outer vacuum rotating drum configured with a plurality of holes thereon, and an inner heavy, cylindrical, solid roller coated with a soft material, said inner roller rotates inside said rotating drum in a non-concentric axis, wherein during rotation said outer vacuum rotating drum singularly picks at least one object from said queue and places at least one object (15) on at least one examination bed (50) such that one examination bed (50) has one object (15).
5) The grading machine as claimed in claim 1, wherein said endless rotating medium is a chain link (65).
6) The grading machine as claimed in claim 1, wherein each said examination bed (50) is a cup or any other object holding shape and said plurality of examination beds (50) are arranged adjacent to each other to form one tray, wherein plurality of trays are interlinked via said chain link (65) to make said conveyor (60).
7) The grading machine as claimed in claim 1, wherein said ejection unit (120) comprises of equal number of said temporary magnets/ electromagnetic coils (124) along with equal number of respective ejector controller (122) and equal number of said examination beds (50) so that each said examination bed (50) is ejected individually by respective said ejector controller (122) through respective temporary magnet/electromagnetic coil (124) according to ‘defined grade data’ of each said object (15).
8) The grading machine as claimed in claim 1, wherein said material of said core gets de-magnetised completely as soon as the magnetic force is removed, said negligible retentivity of said core is further minimized by an external coercive force which provides negligible retentivity after de-magnetisation along with higher magnetic flux density during magnetisation for maintaining higher saturation point of magnetic flux for controlled ejection of smaller sized objects.

9) The grading machine as claimed in claim 1, wherein said objects (15) are ejected from said examination beds (50) to respective ‘pre-determined grade containers’ (126) through respective chutes (128).
10) A method for grading smaller sized objects (15) by using a grading machine, said method comprising:

• feeding at least one controller (10) with predetermined feed rate of objects, ‘pre-determined area of the examination bed’, ‘pre-determined size of a permanent magnet’, ‘pre-determined grade container parameter’ and ‘pre-determined grade parameters’, in a second storage module (12) of said controller (10);
• actuating a conveyor (60), wherein said conveyor (60) includes a rotating medium which is connected to plurality of dampers at ‘pre-determined distance’ underneath of said endless rotating medium and in contact with said endless rotating medium in between a first place and a second place for damping/absorbing/controlling shock/vibrations generated during receiving, conveying and ejecting objects (15) in the grading machine;introducing objects (15) in an object introducing unit (20) for receiving objects (15);
• feeding, through an in-feed unit (30), at least one object, wherein said feed rate of objects (15) is controlled by said controller (10) by said pre-determined feed rate fed in said controller (10), and said feeding enabling objects (15) to move in at least one queue;
• singulating objects (15) received from said in-feed unit (30) in at least one singulator (40);
• disposing at least one singulated object respectively on at least one examination bed, wherein each examination bed (50) is of a per-determined area with embedded permanent magnet (80) and each examination bed (50) with embedded magnet moves with a

conveyor (60) having endless rotating medium; exposing said each examination bed (50) embedded with permanent magnet (80) to at least two optics units (90a and 90b);
• capturing multi-angled real-time one/multiple images of each object in three dimensional space, wherein said object is disposed on each examination bed (50) embedded with permanent magnet (80), under examination by a plurality of cameras and light sources of said optics units (90a and 90b);
• processing said image in a image processor unit of said optics unit, wherein said one/multiple images are processed into at least one ‘grade parameter’;
• storing each said ‘grade parameter’ in a first storage module of said optics units (90a and 90b);
• comparing said ‘grade parameter’ stored in said first storage module with a ‘pre-determined grade parameters’ stored in a second storage module by using a grading comparator, wherein said second storage module and said grading comparator are configured in said controller (10);
• determining a ‘defined grade data’ of each object (15) disposed on each said examination bed (50) by said controller (10);
• locating pre-determined grade containers (126) based on ‘pre-defined grade data’ of said objects (15) disposed on each said examination bed (50) by said controller (10) and remembering location of each said object (15) of ‘defined grade data’ while conveying on said conveyor (60);
• signaling an ejector controller (122) by said controller (10), when said objects (15) disposed on each said examination bed (50) reaches a pre-determined location on said conveyor (60) for permitting flow of current in respective temporary magnets (124), when each respective temporary magnets (124) coincide with each respective embedded permanent magnets (80) of respective examination beds (50), wherein said permanent

magnet (80) is made of a material having high magnetic flux density during magnetisation;
• actuating respective temporary magnets (124) as defined by said ejector controller (122), wherein said temporary magnet (124) includes an electromagnetic coil wound around a core and said core is made of material having negligible retentivity;
• generating a required maximum magnetic flux density in between said respective temporary magnets (124) and said respective permanent magnets (80) with pre-determined bed area, thereby repelling said respective permanent magnets (80) of each examination bed (50) proximal to respective said ‘pre-determined grade container’ (126), thereafter opening said respective examination beds (50);
• directing said objects (15) of ‘defined grade data’ proximal to said grade container (126) for ejecting said objects (15) in said respective grade containers (126) for collecting said objects (15) of ‘defined grade data’ therein; and
• de-actuating actuated respective temporary magnets (124) to de-magnetize respective permanent magnets (80), for completely de-magnetizing said respective temporary magnets (124) with negligible retentivity therewithin and thereby de-magnetizing said respective permanent magnets (80) such that after de-magnetisation, said negligible retentivity of said respective temporary magnets (124) is removed by an external coercive force for closing narrow hysteresis loop created therewithin for maintaining higher saturation point of magnetic flux for accurate ejection of said objects (15) and retentivity of said permanent magnet (80) is brought back to zero by an applying an external coercive force for closing broad hysteresis loop created therewithin, wherein closing of said hysteresis loop created by said respective permanent magnets (80) is in proportionate to the pre-determined area of said examination bed (50), thereby, creating maximum flux density during magnetisation for accurate ejection of smaller sized objects, enabling

multiple grading of said objects (15) of ‘defined grade data’ in a single pass in an automated, controlled and synchronous manner with said conveyor (60).