Claims:We Claim:

1. A method for online marking on a metallic sheet (1), in a metal rolling process, the method comprising:
moving, a laser optical arrangement (2a) to a marking region of the metallic sheet (1) by a retraction mechanism (5), wherein the laser optical arrangement (2a) is housed in an enclosure (3), and configured to receive and direct a laser beam from a source (2b), for marking the metallic sheet (1);
identifying, by a sensor (4), a cobbled portion on the metallic sheet (1), wherein, the cobbled portion is identified during at least one of initiation of the online marking, and during course of the online marking of the metallic sheet (1);
retracting, the enclosure (3) away from the metallic sheet (1) and stopping a rolling mechanism (13), to terminate operation of the online marking, upon identifying the cobbled portion on the metallic sheet (1);
moving, the enclosure (3) to the marking region, after rectifying the cobbled portion of the metallic sheet (1); and
initiating, the online marking on the metallic sheet (1) within a laser marking parameters associated with the metal rolling process.

2. The method as claimed in claim 1, comprising displacing a mirror assembly (7) of the laser optical arrangement (2a), by a motor (8), to deflect the laser beam on to the metallic sheet (1).

3. The method as claimed in claim 2, comprising controlling, by an electronic control unit (9), operation of the motor (8) based on the laser marking parameters.

4. The method as claimed in claim 1, wherein the laser marking parameters, includes rate of marking on the metallic sheet (1), temperature range at which the laser optical arrangement (2a) is maintained, wavelength of the laser beam emitted, and displacement of the metallic sheet (1) on the rolling mechanism (13).

5. The method as claimed in claim 4, wherein marking on the metallic sheet (1) by the laser optical arrangement (2a), is performed at a rate ranging from about 5 m/s to about 25 m/s.

6. The method as claimed in claim 4, wherein marking on the metallic sheet (1) by the laser optical arrangement (2a) produces a mark with a depth ranging from about 20µm to about 45µm.

7. The method as claimed in claim 4, wherein displacement, of the metallic sheet (1) by the rolling mechanism (13) relative to the enclosure (3) is at a rate of about 2m/s to about 20m/s.

8. The method as claimed in claim 1, wherein identifying the cobbled portion by the sensor (4), comprising:
suspending a conductor element (11), from a boom (10), wherein the conductor element (11) positioned proximal to the metallic sheet (1) such that the conductor element (11) contacts at least a portion of the cobbled portion of the metallic sheet (1).

9. The method as claimed in claim 8, wherein the conductor element (11) is positioned at a height of about 100mm to about 500 mm, from the metallic sheet (1).

10. The method as claimed in claim 1, wherein termination of the online marking on the metallic sheet (1) is performed by a relay unit (12) associated with the sensor (4).

11. The method as claimed in claim 10, wherein the relay unit (12) is configured to regulate power supply to the rolling mechanism (13).

12. The method as claimed in claim 1, comprising cooling, the laser optical arrangement (2a) within the enclosure (3), the cooling comprises:
channelizing, a first coolant through at least two cascading layers (16) of at least one side wall of a plurality of side walls (15) of the enclosure (3); and
channelizing, a second coolant through a base member (17) connected to each of the plurality of side walls (15), to cool the laser optical arrangement (2a).

13. The method as claimed in claim 12, comprising configuring the base member (17) to a retraction mechanism (5), wherein the base member (17) is adapted to be displaced over a metallic sheet (1).

14. The method as claimed in claim 12, comprises housing an auxiliary cooling unit (18) within the plurality of side walls (15), to maintain the laser optical arrangement (2a) at the optimum working temperature, when at least one of the first cooling media and the second cooling media are non-operative.

15. The method as claimed in claim 12, comprising actuation of a window (19) defined in the base member (17) of the enclosure (3), wherein the window (19) is configured to assist exposure of the laser optical arrangement (2a), when the enclosure (3) is over the metallic sheet (1).

16. A system (100) for online marking on a metallic sheet (1), in a metal rolling process, the system (100) comprising:
a laser optical arrangement (2a) aligned in a marking region over the metallic sheet (1), the laser optical arrangement (2a) is configured to receive and direct a laser beam from a source (2b) onto the metallic sheet (1), wherein the laser optical arrangement (2a) is housed in an enclosure (3);
a sensor (4) positioned proximal to the metallic sheet (1), the sensor (4) is configured to identify a cobbled portion of the metallic sheet (1) during at least one of initiation of the online marking, and during course of the online marking of the metallic sheet (1); and
a retraction mechanism (5) adapted to displace the enclosure (3) over the metallic sheet (1), wherein the retraction mechanism (5) is configured to retract the enclosure (3) upon identification of the cobbled portion, and realign the enclosure (3) for online marking upon correction of the cobbled portion.

17. The system (100) as claimed in claim 16, wherein the laser optical arrangement (2a), comprises:
a laser scanning unit (6) encompassed in the enclosure (3), the laser scanning unit (6) is configured to receive the laser beam;
a mirror assembly (7) positioned proximal to the laser scanner unit, the mirror assembly (7) is configured to direct the laser beam transmitted from the laser scanner unit; and
a motor (8) adapted to displace the mirror assembly (7), wherein the motor (8) is controlled by an electronic control unit (9), based on the laser marking parameters, to mark the metallic sheet (1).

18. The system (100) as claimed in claim 16, wherein the laser beam emitted from the laser optical arrangement (2a), is in a wavelength ranging from about 1065 nm to about 1075 nm.

19. The system (100) as claimed in claim 16, wherein the sensor (4) comprising:
a boom (10) adapted to extend over the metallic sheet (1);
a conductor element (11) suspending from the boom (10), the conductor element (11) is positioned proximal to the metallic sheet (1), wherein the conductor element (11) contacts a portion of the metallic sheet (1) when the metallic sheet (1) has surface irregularity; and
a relay unit (12) associated with a rolling mechanism (13) of the metallic sheet (1) and the conductor element (11), to arrest operation of a rolling mechanism (13) upon contact of the conductor element (11) with the metallic sheet (1).

20. The system (100) as claimed in claim 19, wherein the conductor element (11) is positioned at a height of about 100 mm to about 500 mm, from the metallic sheet (1).

21. The system (100) as claimed in claim 16, wherein the enclosure (3), comprises:
a top cover (14);
a plurality of side walls (15) extending from the top cover (14) to house the laser optical arrangement (2a), wherein at least one side wall of the plurality of side walls (15) comprises at least two cascading layers (16), wherein the at least two cascading layers (16) are configured to channelize flow a first coolant; and
a base member (17) connected to each of the plurality of side walls (15), the base member (17) is adapted to channelize flow of a second coolant,
wherein the base member (17) is configurable to a retraction mechanism (5), to displace the enclosure (3) over the metallic sheet (1).

22. The system (100) as claimed in claim 21, wherein the first coolant and the second coolant maintains the laser optical arrangement (2a) at an optimum working temperature.
23. The system (100) as claimed in claim 22, comprises an auxiliary cooling unit (18) housed within the plurality of side walls (15), to maintain the laser optical arrangement (2a) at the optimum working temperature, when at least one of the first coolant and the second coolant are non-operative.

24. The system (100) as claimed in claim 23, wherein the optimum working temperature of the laser optical arrangement (2a) is about 15ºC to about 75ºC.

25. The system (100) as claimed in claim 21, comprises a window (19) defined in the base member (17), wherein the window (19) is configured to allow passage of a laser beam emitted from the laser optical arrangement (2a).

26. The system (100) as claimed in claim 25, comprises a blower (20) at a peripheral portion of the window (19), to inhibit entry of foreign particles during operation of the laser optical arrangement (2a).

27. The system (100) as claimed in claim 25, wherein the window (19) is provisioned with an actuation means, to selectively expose the laser optical arrangement (2a), when the enclosure (3) is aligned over the metallic sheet (1).

28. The system (100) as claimed in claim 21, wherein the enclosure (3) is adapted to be exposed to a temperature ranging from about 75ºC to about 325ºC.

29. The system (100) as claimed in claim 16, wherein the metallic sheet (1) is maintained at a temperature ranging from about 500ºC to about 900ºC, during online marking.
, Description:TECHNICAL FIELD
Present disclosure relates in general to a field of manufacturing engineering. Particularly, but, not exclusively, the present disclosure relates to a method of laser marking on a metallic sheet. Further, embodiments of the present disclosure discloses a method and a system for online marking on the metallic sheet, in a metal rolling process.

BACKGROUND

Generally, in metal working processes and post casting processes, metal billets may be passed through one or more rollers, where the metal billets are recurrently subjected to compressive forces to reduce their thickness. Such recurrent compressive forces assists in gradual reduction of thickness along the length of the metal billet, to produce metallic sheets. Further, in order to minimize efforts applied by the one or more rollers, the metal billet is maintained at an elevated temperature, for ease in deformation and manufacturing thereof. The elevated temperature for the rolling process may vary from metal to metal, and may depend on properties of the metal. Further, the rolling process would be followed by coiling of the metal sheets formed therein. Before coiling, the metallic sheets may be marked with different patterns to inscribe different indications on the metal sheets. As an example, the different indications may include, but not limited to, manufacturers’ name, grade of the metal, gauge of the metallic sheet, and the like.

Currently, for marking the metallic sheets, various methodologies or techniques such as, but not limited to, chemical etching, laser alloying, laser marking, and the like, are employed. Of these methodologies, laser marking is one of the most commonly used, as this can be performed at rapid speeds and without having to compromise on quality of the mark. Maintaining the laser marking apparatus over the metallic sheets for prolonged times will damage the laser marking apparatus. Due to the high temperature of the metallic sheet, heat waves may be generated therefrom, which may tend to deform the components associated with laser generation and deflection apparatus. Meanwhile, if the temperature of the metallic sheet is lowered, then coiling process may be affected.

Additionally, the metallic sheets produced during the rolling process may be subjected to irregularities including, but not limited to, cobbling, during conveying or transportation from one metal working station to another. Cobbling effect leads to uncontrolled lashing of the metallic sheet on the laser marking apparatus thereby damaging the marking apparatus. Also, cobbling on the metal sheet may lead to inconsistent coiling during coiling process. Moreover, the cobbling of the metallic sheet may affect the marking to be produced therein, as there would be inconsistency during marking.

The present disclosure is directed to overcome one or more limitations stated above or any other limitation associated with the prior arts.

SUMMARY OF THE DISCLOSURE

One or more shortcomings of the prior art are overcome by a method as disclosed and additional advantages are provided through the method as described 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 one non-limiting embodiment of the disclosure, a method for online marking on a metallic sheet, in a metal rolling process, is disclosed. The method comprises steps of moving, a laser optical arrangement to a marking region of the metallic sheet by a retraction mechanism. The laser optical arrangement is housed in an enclosure, and configured to receive and direct a laser beam from a source, for marking the metallic sheet. Further, a sensor is configured to identify a cobbled portion on the metallic sheet. The cobbled portion is identified during at least one of initiation of the online marking, and during course of the online marking of the metallic sheet. Upon identifying the cobbled portion on the metallic sheet, the enclosure is adaptively retracted away from the metallic sheet, while a rolling mechanism employed to transport the metallic sheet is stopped, to terminate operation of the online marking. Thereafter, the enclosure is moved to the marking region, after rectifying the cobbled portion of the metallic sheet. The online marking on the metallic sheet is initiated, within laser marking parameters associated with the metal rolling process.

In an embodiment, the method comprises displacing a mirror assembly of the laser optical arrangement, by a motor, to deflect the laser beam on to the metallic sheet. Further, an electronic control unit controls operation of the motor, based on the laser marking parameters.

In an embodiment, the laser marking parameters, includes rate of marking on the metallic sheet, temperature range at which the laser optical arrangement is maintained, wavelength of the laser beam emitted, and displacement of the metallic sheet on the rolling mechanism. The marking on the metallic sheet by the laser optical arrangement, is performed at a rate ranging from about 5 m/s to about 25 m/s. The marking on the metallic sheet by the laser optical arrangement produces a mark with a depth ranging from about 20µm to about 45µm. Further, displacement, of the metallic sheet by the rolling mechanism relative to the enclosure is at a rate of about 2m/s to about 20m/s.

In an embodiment, identifying the cobbled portion by the sensor, comprises suspending a conductor element, from a boom. The conductor element is positioned proximal to the metallic sheet such that the conductor element contacts at least a portion of the cobbled portion of the metallic sheet.

In an embodiment, the conductor element is positioned at a height of about 100 mm to about 500 mm, from the metallic sheet.

In an embodiment, termination of the online marking on the metallic sheet is performed by a relay unit associated with the sensor.

In an embodiment, the relay unit is configured to regulate power supply to the rolling mechanism.

In an embodiment, the method comprises cooling the laser optical arrangement within the enclosure. The cooling comprises channelizing, a first coolant through at least two cascading layers of at least one side wall of a plurality of side walls of the enclosure. Further, channelizing, a second coolant through a base member connected to each of the plurality of side walls, to cool the laser optical arrangement.

In an embodiment, the method comprises configuring the base member to a retraction mechanism, wherein the base member is adapted to be displaced over a metallic sheet.

In an embodiment, the method comprises housing an auxiliary cooling unit within the plurality of side walls, to maintain the laser optical arrangement at the optimum working temperature, when at least one of the first cooling media and the second cooling media are non-operative.

In an embodiment, the method comprises actuation of a window defined in the base member of the enclosure, wherein the window is configured to assist exposure of the laser optical arrangement, when the enclosure is over the metallic sheet.

In another non-limiting embodiment of the present disclosures, a system for online marking on a metallic sheet, in a metal rolling process. The system comprises a laser optical arrangement aligned in a marking region over the metallic sheet. The laser optical arrangement is configured to receive and direct a laser beam from a source onto the metallic sheet, wherein the laser optical arrangement is housed in an enclosure. Further, a sensor is positioned proximal to the metallic sheet, and is configured to identify a cobbled portion of the metallic sheet during at least one of initiation of the online marking, and during course of the online marking of the metallic sheet. Additionally, the system includes a retraction mechanism, adapted to displace the enclosure over the metallic sheet. The retraction mechanism is configured to retract the enclosure upon identification of the cobbled portion, and realign the enclosure for online marking upon correction of the cobbled portion.

In an embodiment, the laser optical arrangement comprises a laser scanning unit, encompassed in the enclosure, configured to receive the laser beam. Further, a mirror assembly is positioned proximal to the laser scanner unit, and is configured to direct the laser beam transmitted from the laser scanner unit. Also, a motor is adapted to displace the mirror assembly. The motor is controlled by an electronic control unit, based on the laser marking parameters, to mark the metallic sheet.

In an embodiment, the laser beam emitted from the laser optical arrangement, is in a wavelength ranging from about 1065 nm to about 1075 nm.

In an embodiment, the sensor comprises a boom, which is adapted to extend over the metallic sheet. Further, a conductor element suspending from the boom, the conductor element is positioned proximal to the metallic sheet. The conductor element contacts a portion of the metallic sheet when the metallic sheet has the cobbled portion. Further, the sensor includes a relay unit associated with a rolling mechanism of the metallic sheet and the conductor element. The relay unit arrests operation of a rolling mechanism upon contact of the conductor element with the metallic sheet.

In an embodiment, the conductor element is positioned at a height of about 100 mm to about 500 mm, from the metallic sheet.

In an embodiment, the enclosure comprises a top cover, a plurality of side walls extending from the top cover to house the laser optical arrangement. Further, at least one side wall of the plurality of side walls comprises at least two cascading layers, where the at least two cascading layers are configured to channelize flow of a first coolant. Additionally, a base member connected to each of the plurality of side walls, and is adapted to channelize flow of a second coolant. The base member is further configurable to a retraction mechanism, to displace the enclosure over the metallic sheet.

In an embodiment, the first coolant and the second coolant maintains the laser optical arrangement at an optimum working temperature.

In an embodiment, the enclosure comprises an auxiliary cooling unit housed within the plurality of side walls, to maintain the laser optical arrangement at the optimum working temperature, when at least one of the first coolant and the second coolant are non-operative.

In an embodiment, the optimum working temperature of the laser optical arrangement is about 15ºC to about 75ºC.

In an embodiment, the enclosure comprises a window defined in the base member. The window is configured to allow passage of a laser beam emitted from the laser optical arrangement.

In an embodiment, the enclosure comprises a blower at a peripheral portion of the window, to inhibit entry of foreign particles during operation of the laser optical arrangement.

In an embodiment, the window is provisioned with an actuation means, to selectively expose the laser optical arrangement, when the enclosure is aligned over the metallic sheet.

In an embodiment, the enclosure is adapted to be exposed to a temperature ranging from about 75ºC to about 325ºC.

In an embodiment, the metallic sheet is maintained at a temperature ranging from about 500ºC to about 900ºC, during online marking.

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 ACCOMPANYING FIGURES

The novel features and characteristics of the disclosure are set forth in the appended description. 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 a schematic representation of a system for online marking on a metallic sheet, in accordance with an embodiment of the present disclosure.

Figure 2 illustrates a schematic view of a laser optical arrangement employed in the system, in accordance with an embodiment of the present disclosure.

Figure 3a illustrates a schematic perspective view of an enclosure employed in the system, in accordance with an embodiment of the present disclosure.

Figure 3b illustrates a magnified view of portion B in Figure 3a.

Figure 4 illustrates a schematic representation of retraction mechanism coupled to the enclosure, in accordance with an embodiment of the present disclosure.

Figure 5a illustrates a perspective view of an online marking station having a sensor of the system, in accordance with an embodiment of the present disclosure.

Figure 5b illustrates a magnified view of portion C in Figure 5a.

Figure 6 is a flow chart which describes a method for online marking on a metallic sheet, in a metal rolling process, in accordance with an embodiment of the present disclosure.

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 methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF THE DISCLOSURE

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 description of the disclosure. It should also be realized by those skilled in the art that such equivalent methods and systems do not depart from the scope of the disclosure. The novel features which are believed to be characteristic of the disclosure, as to 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.

In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and the scope of the disclosure.

The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a method and a system that comprises a list of acts does not include only those acts but may include other acts not expressly listed or inherent to such method. In other words, one or more acts in a method proceeded by “comprises… a” does not, without more constraints, preclude the existence of other acts or additional acts in the method.

Embodiments of the present disclosure discloses a method for online marking on a metallic sheet, in a metal rolling process. The method comprises steps of moving, a laser optical arrangement to a marking region of the metallic sheet by a retraction mechanism. The laser optical arrangement is housed in an enclosure, and configured to receive and direct a laser beam from a source, for marking the metallic sheet. Further, a sensor is configured to identify a cobbled portion on the metallic sheet. Since, the cobbled portion of the metallic sheet may collide with the laser marking apparatus, or may produce a heat wave which may cause components of the laser optical arrangement to heat up and fail. Hence, the cobbled portion is required to be identified and rectified, before commencing with the online marking. The cobbled portion is identified during at least one of initiation of the online marking, and during course of the online marking of the metallic sheet. Upon successful identification of the cobbled portion on the metallic sheet, the enclosure may be retracted away from the metallic sheet, while a rolling mechanism employed to transport the metallic sheet may be halted or made non-operational in order to terminate operation of the online marking, and rectification of the cobbled portion may be carried out. Once the cobbled portion of the metallic sheet is rectified, the enclosure is moved to the marking region. The online marking on the metallic sheet may be then initiated, within laser marking parameters associated with the metal rolling process.

Additionally, the embodiments also discloses a system for online marking on the metallic sheet, in the metal rolling process. The system comprises the laser optical arrangement aligned in the marking region over the metallic sheet. The laser optical arrangement is configured to receive and direct a laser beam from a source onto the metallic sheet, wherein the laser optical arrangement is housed in the enclosure. Further, the sensor is positioned proximal to the metallic sheet, and is configured to identify the cobbled portion of the metallic sheet during at least one of initiation of the online marking, and during course of the online marking of the metallic sheet. Additionally, the system includes the retraction mechanism, adapted to displace the enclosure over the metallic sheet. The retraction mechanism is configured to retract the enclosure upon identification of the cobbled portion, and realign the enclosure for online marking upon correction of the cobbled portion.

Henceforth, the present disclosure is explained with the help of figures of a method for online marking on a metallic sheet, in a metal rolling process, and a system thereof. However, such exemplary embodiments should not be construed as limitations of the present disclosure, since the method or the system may be used on other types of metallic materials such as, but not limited to, iron, steel, aluminum, and the like, where such need arises. A person skilled in the art can envisage various such embodiments without deviating from scope of the present disclosure.

Figure 1 is an exemplary embodiment of the present disclosure, which is a schematic representation of a system (100) for online marking [herein also referred to as “the system (100)”]. A manufacturing plant [not shown in Figures], includes the system (100) in a marking station, positioned proximal to a finish roll-milling station [not shown in Figures]. In accordance with various embodiments of the disclosure, the online marking of the metallic sheet may be performed proximal a rolling station. As known in the art, rolling is a process of reducing thickens of the metallic material. The metallic material also called as workpiece, which is at least one of a billet, a bloom, and a slab. The workpiece may be subjected to a continuous rolling process, to produce a metallic sheet (1). The metallic sheet (1) departing from the finish roll-milling station, after the continuous rolling process, is configured to be transported to a coiling station, via a conveyer system comprising a rolling mechanism (13). The metallic sheet (1) may be subjected to a coiling process in the coiling station, to coil the metallic sheet (1). According to embodiments of the disclosure, prior to commencing with the coiling process, the metallic sheet (1) may be subjected to a marking process at the marking station.

The online marking of the metallic sheet may be performed by positioning the system (100) for online marking in the marking station. The marking station used herein above and below may correspond to region of the metallic sheet (1) to be marked, and the same may vary depending on the requirement. The system (100) includes a laser marking apparatus, where the laser marking apparatus consists of a source (2b) located proximal to the marking station. A laser optical arrangement (2a), is housed within an enclosure (3), and is adaptably positioned proximal to the conveyer system such that, the laser optical arrangement (2a) may be displaced either over a marking region on the metallic sheet (1), or away from the marking region. Further, the enclosure (3) is coupled to a retraction mechanism (5), which assists in moving the enclosure (3) over the metallic sheet (1), that is, to the marking region, or away therefrom. The retraction mechanism (5) is communicatively coupled to a sensor (4), which is positioned over the metallic sheet (1), and identifies irregularities such as, but not limited to, a cobbled portion in the metallic sheet (1), prior to commencing the online marking or during course of the online marking of the metallic sheet (1). The sensor (4) is also communicatively coupled with the rolling mechanism (13) of the conveyer system so that, when the sensor (4) detects the irregularities, the rolling mechanism (13) is halted from transporting the metallic sheet (1) further. This avoids the marking region of the metallic sheet (1) containing the irregularities being marked, by the laser optical arrangement (2a). In an embodiment, the online marking on the metallic sheet (1) may be performed within laser marking parameters associated with the metal rolling process.

The source (2b) is positioned away from the conveyer system, in order to avoid interference and effects of heat waves transmitted from the metallic sheet (1). Meanwhile, the laser optical arrangement (2a) housed within the enclosure (3), is configured to be moved proximal to the conveyer system, in accordance with the requirement of operating the laser optical arrangement (2a). In an embodiment, to initiate the online marking on the metallic sheet (1), the enclosure (3) consisting of the laser optical arrangement (2a) is moved over to the marking region of the metallic sheet (1), as best seen in Figure 1. The source (2b) is then either manually or automatically operated to produce a plurality of laser beams, which are subsequently guided via a plurality of optical fibers to a combiner module, housed within the source (2b) [not shown in Figures]. The combiner module is adapted to combine and/or splice the plurality of optical fibers to produce a single optical fiber [not shown in Figures], which in-turn combines the plurality of laser beams to form a single laser beam. The unit optical fiber may be adapted to channelize and/or guide the laser beam to the laser optical arrangement (2a).

Now referring to Figure 2, which discloses a laser scanning unit (6) of the laser optical arrangement (2a) which is encompassed in the enclosure (3), and is adapted to receive the laser beam from the single optical fiber is extended from the source (2b). The laser scanning unit (6) is in communication with a mirror assembly (7), to receive the laser beam. In an embodiment, the mirror assembly (7) may either be a series of mirrors positioned at an angle, or a polygonal mirror positioned on a rotatable shaft. The mirror assembly (7) is further adapted to guide and/or reflect the laser beam in a defined direction, by virtue of rotational motion imparted by a motor (8) provisioned therein. The motor (8) may be controlled by an electronic control unit (9) [not shown in Figures], to rotate the mirror assembly (7) in a pre-set pattern, whereby the laser beam is selectively guided and/or reflected along the pre-set pattern on the marking region of the metallic sheet (1). In an embodiment, the electronic control unit (2) may be communicatively coupled to a memory unit [not shown in Figures]. The memory unit may be store the data pertaining to the pre-set patterns to be created on the metallic sheet (1). The electronic control unit (9) selectively operates the motor (8) based on the pre-set patterns, to assist in deflecting the laser beam from the mirror assembly (7). However, the laser optical arrangement (2a) would inherently be exposed to heat being radiated from the metallic sheet (1), which would affect the performance of the laser optical arrangement (2a). In order to inhibit the influence of the heat, the enclosure (3) is configured to heat shield the laser optical arrangement (2a) and the mirror assembly (7).

In an embodiment, the enclosure (3) includes a plurality of side walls (15), which extend from a top cover (14), as shown in Figure 3a. Further, a base member (17) is connected to each of the plurality of side walls (15), thereby defining a compartment for housing the laser optical arrangement (2a) and the mirror assembly (7). The enclosure (3) is configured to cool the laser optical arrangement (2a) and the mirror assembly (7) from the heat transmitted by the metallic sheet (1), during the online marking. The plurality of side walls (15) of the enclosure (3) include at least one wall which comprises of at least two cascading layers (16). The at least two cascading layers (16) are configured with channels and/or conduits [not shown in figures], to channelize flow of a first coolant, which may be circulated therethrough. Further, the base member (17) is also configured with channels and/or conduits to channelize flow of a second coolant, in order to restrict impact of the heat wave from underneath the enclosure (3). In an embodiment, the enclosure (3) includes an auxiliary cooling unit (18) housed within the plurality of side walls (15), to maintain the laser optical arrangement (2a) at an optimum working temperature. The auxiliary cooling unit (18) is operated when the first coolant and the second coolant is not channelized within the enclosure (3). Also, as the base member (17) is proximal to the metallic sheet (1), radiant heat from the metallic sheet may be considerably higher and hence, a grooved plate [not shown in Figures] is provisioned on the base member (17), where the grooved plate is configured to channelize additional flow of the first coolant, based on requirement.

In addition, a window (19) is defined in the base member (17) of the enclosure (3). The window (19) is configured to expose the laser optical arrangement (2a) to the metallic sheet (1). The window (19) further allows passage of the laser beam emitted from the laser optical arrangement (2a), for marking the metallic sheet (1). However, during online marking on the metallic sheet (1), due to presence of the window (19), foreign particles including, but not limited to, metallic chips, dust, and the like may rise from surface of the metallic sheet (1) and may enter the enclosure (3). The entry of the foreign particles may interfere the operation of the laser optical arrangement (2a). Therefore in order to mitigate entry of such foreign particles, a blower (20) may be provisioned at a peripheral portion of the window (19), as best seen in Figure 3b. The blower (20) is configured to discharge pressurized air along the direction of laser beam emitted therefrom such that, the foreign particles travelling from the surface of the metallic sheet (1) is restricted from entering the enclosure (3). This action of the blower (20) assists in inhibiting entry of the foreign particles into the enclosure (3), during the online marking. Also, in order to inhibit entry of the foreign particles during non-operation of the laser optical arrangement (2a), a pneumatic door assembly (21) may be arranged to cover the window (19). Additionally, a side portion of the window (19) which is exposed to the metallic sheet (1) is subjected to gas purging so that, a positive pressure is created within the enclosure (3) to inhibit entry of the foreign particles therein.

In an embodiment, the marking portion on the metallic sheet (1) may be defined about 50 mm to about 400 mm from a longitudinal edge of the metallic sheet (1). The enclosure (3) may be positioned proximal to the longitudinal edge of the metallic sheet (1), for online marking. Further, the at least one side wall of the plurality of side walls (15) proximal to the longitudinal edge of the metallic sheet (1) may be provisioned with the at least two cascading layers (16), to channelize the first coolant. Furthermore, the first coolant employed in the enclosure (3) may be including, but not limited to, water, nitrogen, chlorofluorocarbon gases [CFCs], ammonia, and the like. The first coolant may be configured to pass through the plurality channels or conduits [not shown in Figures] provisioned between the at least two cascading layers (16) of the at least one side wall, of the plurality of side walls (15). Additionally, the second coolant may be at least one of nitrogen, an inert gas, and the like, being channelized through the base member (17). Also, the second coolant may be purged outside the window (19) of the base member (17), to assist in producing a positive pressure within the compartment. This purging of the second coolant may assist the operation of the blower (20) to inhibit entry of foreign particles into the enclosure (3), through the window (19), during operation of the laser optical arrangement (2a). It may be noted that the at least two cascading layers (16) is provided to the at least one side wall of the plurality of side walls (15), which is relatively closer to the metallic sheet (1). However, one skilled in the art should not consider this to be a limitation of the enclosure (3) as each of the plurality of side walls (15) may be provisioned with the at least two cascading layers (16), for cooling the laser optical arrangement (2a) and the mirror assembly (7). In addition, the auxiliary cooling unit (18) may be a panel air-conditioning unit, associated with the enclosure (3), to assist and/or support operation of the first coolant and the second coolant, for protecting the laser optical arrangement (3a) and the mirror assembly (7) therein.

Referring to now to Figure 4 which illustrates the retraction mechanism (5), which is operatively coupled to the enclosure (3). In an embodiment, the retraction mechanism (5) includes an electromagnetic mechanism, that comprises of at least one linear motor (22), which is positioned proximal to the base member (17) of the enclosure (3). The at least one linear motor (22) is further provisioned with an electromagnetic means (23), where the electromagnetic means (23) is configured to assist in operation of the at least one linear motor (22), upon actuation. In addition, a pair of rails (24) are provided on either side of the base member (17) and along the length of the at least one linear motor (22). The enclosure (3) displaces on the pair of rails (24), to move over and/or away from the metallic sheet (1). For example, the retraction mechanism (5) may be configured to move the enclosure (3) over the marking region of the metallic sheet (1), during initiation of the online marking. Similarly, the retraction mechanism (5) may be configured to retract the enclosure (3) away from the metallic sheet (1) during non-operation of the online marking, or when an irregularity such as, but not limited to, cobbling, is identified in the metallic sheet (1). This retraction of the enclosure (3) away from the metallic sheet (1), upon identifying the cobbled portion in the metallic sheet (1), would be critical, as the enclosure (3) may be subjected to radiant heat, and may damage the laser optical arrangement (2a) and/or the mirror assembly (7) therein. In an embodiment, an auxiliary retraction mechanism, which may be at least one of a pneumatic mechanism, hydraulic mechanism, electromechanical mechanism, and the like, may be employed in the system, in order to ensure safety of the laser optical arrangement (2a) and/or the mirror assembly (7), in case the electromagnetic mechanism fails. Also, employing the auxiliary retraction mechanism should not be construed as a limitation of the electromagnetic mechanism, and in-turn that of the system.

Figure 5a discloses the online marking station having the sensor (4) of the system (100). The sensor (4) which is configured to identify the cobbled portion on the metallic sheet (1). In an embodiment, the sensor (4) may either be positioned proximal to the finish roll-milling station, or proximal to the enclosure (3), in order to identify the cobbled portion in the metallic sheet (1). In an embodiment, the sensor (4) is supported by a hanging mechanism (25). The hanging mechanism (25) includes a boom (10), which is adapted to extend over the metallic sheet (1), to suspend a conductor element (11). The conductor element (11) is suspended such that, the conductor element (11) may be positioned proximal to the metallic sheet (1), at a height ranging from about 100mm to about 500mm. Further, the conductor element (11) is connected to an electric source (26) and a relay unit (12), as best seen in Figure 5b, where the relay unit (12) is associated with the rolling mechanism (13). The conductor element (11) is configured such that, it contacts the metallic sheet (1) only at the cobbled portion of the metallic sheet (1). Upon contact with the cobbled portion of the metallic sheet (1), the conductor element (11) completes an electrical network formed between the conductor element (11), the metallic sheet (1), the rolling mechanism (13), and the relay unit (12). Further, establishing the electrical network, the relay unit (12) is configured to arrest operation of the rolling mechanism (13), thereby halting movement of the metallic sheet (1). The cobbled portion of the metallic sheet (1) may then be corrected by means including at least one of manual correction and automatic correction, or a combination thereof. After correcting the cobbled portion of the metallic sheet (1), the rolling mechanism (13) may be initiated and/or energized to transport the corrected portion of the metallic sheet (1) through the sensor (4), to re-check for traces of the cobbled portion being unattended. At this juncture, the sensor (4) communicates with the retraction mechanism (5), for moving the enclosure (3) over the metallic sheet (1), in order to re-initiate the online marking. Here, one skilled in the art should not interpret that, the cobbled portion of the metallic sheet (1) is limited to a wavy profile formed on an edge of the metallic sheet (1) due to improper roll during the rolling process. But, the cobbled portion should be considered as any surface irregularity such as, but not limited to, overlaps, spring back of head and tail edges of the metallic sheet (1), and the like. In addition, one skilled in the art should not construe that a single conductor element is employed in the sensor (4), to identify the cobbled portion in the metallic sheet (1). In an embodiment, a plurality of conductor elements may be positioned at various locations across the metallic sheet (1), for simultaneously identifying the cobbled portions in the metallic sheet (1).

Further, the online marking is re-initiated on the metallic sheet (1), by moving the enclosure (3) on the marking region of the metallic sheet (1), while the laser marking parameters associated with the metal rolling process are taken into consideration. In an embodiment, the laser marking parameters, includes rate of marking on the metallic sheet (1), temperature range at which the laser optical arrangement (2a) is maintained, wavelength of the laser beam emitted, and displacement of the metallic sheet (1) on the rolling mechanism (13). In an embodiment, the metallic sheet (1) departing from the finish roll-milling station may be at a temperature ranging from about 500ºC to about 900ºC. The enclosure (3), which is adaptably positioned over the metallic sheet (1) for online marking, may be exposed to the temperature ranging from about 75ºC to about 325ºC. Furthermore, the displacement of the metallic sheet (1) on the rolling mechanism (13) may be in the range of about 2m/s to about 20m/s, for marking. Additionally, marking on the metallic sheet (1) by the laser optical arrangement (2a) produces a mark with a depth ranging from about 20µm to about 45µm. Also, the laser beam produced by the source (2b) may consist of a wavelength ranging from about 1065 nm to about 1075 nm, and may be continuously operated for a streamlined laser beam. Further, direct current (DC) is employed to power the source (2b) for producing the laser beam. The frequency of the modulation in the source (2b) may be maintained between 1KHz to 5KHz. marking on the metallic sheet (1) by the laser optical arrangement (2a), is performed at a rate ranging from about 5 m/s to about 25 m/s.

In an exemplary embodiment, a high-power Ytterbium pulsed laser may be employed as the source (2b) for producing the laser beam. However, any other means of generating the laser beam may also be employed thereto. Further, the laser scanning unit (6) may be include, but not limited to, a galvanometer scanner. The laser scanning unit (6) may be provisioned with an aperture ranging from about 20mm to 40mm, to direct the laser beam on to the mirror assembly (7). In addition, mirror assembly (7) may be displaced within the enclosure (3) at a rate of about 6m/s to 10m/s, in order to suitably deflect the laser beam onto the metallic sheet (1). The laser optical arrangement (2a) may further be configured to mark the metallic sheet (1) at a metallic sheet displacement rate ranging from about 0.3m/s to about 1.2m/s. Additionally, the laser optical arrangement (2a) may be adapted with a good writing quality of about 220 cps, while a high writing quality may be of about 150 cps.

Referring now to Figure 6 which is an exemplary embodiment of the present disclosure illustrating a flow chart of a method for online marking on the metallic sheet (1), in the metal rolling process.

The order in which the method is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the scope of the subject matter described herein.

At block 301, the laser optical arrangement (2a) is moved to the marking region of the metallic sheet (1) by the retraction mechanism (5). The laser optical arrangement (2a) is housed in the enclosure (3), and configured to receive and direct a laser beam from the source (2b), for marking the metallic sheet (1). Here, the enclosure (3) is coupled to the retraction mechanism (5), whereby moving the enclosure (3) would inherently move the laser optical arrangement (2a) for aligning therein, to mark the metallic sheet (1).

Further, at block 302, the sensor (4), positioned proximal and before the enclosure (3), is configured to identify the cobbled portion on the metallic sheet (1). The cobbled portion is identified during at least one of initiation of the online marking, and during course of the online marking of the metallic sheet (1). Additionally, upon identifying the cobbled portion, the sensor (4) is adapted to stop operation of the rolling mechanism (13) of the conveyer system, to halt the metallic sheet (1).

At block 303, in conjunction with halting the metallic sheet (1), the enclosure (3) is retracted away from the metallic sheet (1), to terminate operation of the online marking. The cobbled portion on the metallic sheet (1) may be manually and/or automatically rectified, based on requirement, and then the enclosure (3) is moved back to the marking region, for marking, as at Block 304. The laser optical arrangement (2a) is moved back to initiate the online marking on the metallic sheet (1).

In an embodiment of the present disclosure, the metallic sheets for the online marking process may be including, but not limited to, iron, steel, copper, aluminum, and the like. Meanwhile, one skilled in the art should not limit the term metallic sheet (1) to comprise only metallic elements, but, should interpret the term metallic in the broadest sense to includes alloys, associated with each metallic element. The metallic sheet (1) may be comprise a thickness ranging from about 1 mm to 20 mm.

In an embodiment, the laser optical arrangement (2a) and the mirror assembly (7) are protected from the heat of the metallic sheet (1), due to which prolonged operation of the online marking may be feasible. This increases the run time of the marking station.

In an embodiment, due to identification of the cobbled portion on the metallic sheet (1) and instantaneous retraction of the enclosure (3), the system (100) is fail-proof arising from any impact between the enclosure (3) and the metallic sheet (1).

EQUIVALENTS

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”

In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Referral Numerals:
Particulars Numeral
Metallic sheet 1
Laser optical arrangement 2a
Source 2b
Enclosure 3
Sensor 4
Retraction mechanism 5
Laser scanning unit 6
Mirror assembly 7
Motor 8
Electronic control unit 9
Boom 10
Conductor element 11
Relay unit 12
Rolling mechanism 13
Top cover 14
Plurality of side walls 15
Cascading layers 16
Base member 17
Auxiliary cooling unit 18
Window 19
Blower 20
Pneumatic door assembly 21
linear motor 22
Electromagnetic means 23
Pair of rails 24
Hanging mechanism 25
Electric source 26