DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
A DEVICE FOR MARKING OF PRESSURE HULL ON A MARINE VESSEL

Applicant:
Mazagon Dock Shipbuilders Limited
A company Incorporated in India under the Companies Act, 1956
Under Ministry of Defence,
(A Govt. of India Undertaking)
Having address:
Dockyard Road, Mazagon,
Mumbai - 400010, Maharashtra, India

The following specification particularly describes the invention and the manner in which it is to be performed.

CROSS-REFERENCE TO RELATED APPLICATION AND PRIORITY
[001] The present application claims priority from Indian Patent application no. (201821043548) filed on 19th November, 2018.

TECHNICAL FIELD
[002] The present subject matter described herein generally relates to a device for marking of a pressure hull on a marine vessel, and more specifically to a device for simultaneously marking on two sides of a pressure hull on a marine vessel.

BACKGROUND
[003] Marine vessels are provided with coamings on the edges of the marine vessel. The coamings are installed on the marine vessel after cutting pressure hull. The pressure hull is having a significant thickness and are to be cut in a particular shape to install the coamings. Conventionally a jig is used to mark a circle on the surface of the pressure hull. This jig can mark on one side of the pressure hull at a time. After marking on one side of the pressure hull, the jig is need to be removed and then again need to be fitted on other side of the pressure hull. This removal and again fitting the jig incur in errors during the marking and a high degree of skills are required to complete the marking on both sides of the pressure hull. The current subject matter provides an improved and efficient device to simultaneously mark on two sides of a pressure hull on a marine vessel.

SUMMARY
[004] Before the present device is described, it is to be understood that this application is not limited to the particular machine or device, as there can be multiple possible embodiments that are not expressly illustrated in the present disclosures. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to a device and method for marking and cutting of a pressure hull, and the aspects are further elaborated below in the detailed description. This summary is not intended to identify essential features of the proposed subject matter nor is it intended for use in determining or limiting the scope of the proposed subject matter.
[005] The present subject matter describes a device for simultaneously marking on two sides of a pressure hull on a marine vessel. The device comprises a marking tube, a first marking arm and a second marking arm. The marking tube passes through a hole on the pressure hull. One end of the first marking arm is movably coupled to the marking tube on one side of the pressure hull and other end of the first marking arm comprises a first scriber. One end of the second marking arm is movably coupled to the marking tube on other side of the pressure hull and other end of the second marking arm comprises a second scriber. During operation of the device the first marking arm and the second marking arm are rotatable about the axis of the marking tube and movable along the axis of the marking tube and thereby simultaneously marking on two sides of the pressure hull.
[006] It is an object of the present subject matter to provide a device for simultaneously marking on two sides of a pressure hull on a marine vessel without removing the device during the marking operation.
[007] The present subject matter further describes a method of marking and cutting the pressure hull of a marine vessel. The method comprises the steps of: making a hole on the pressure hull, inserting a marking tube in the hole, coupling one end of a first marking arm to the marking tube on one side of the pressure hull and coupling a first scriber removably to other end of the first marking arm, coupling one end of a second marking arm to the marking tube on other side of the pressure hull and coupling a second scriber removably to other end of the second marking arm, moving the first scriber on the first marking arm to set the radius of the marking on one side of the pressure hull, moving the second scriber on the second marking arm to set the radius of the marking on other side of the pressure hull, rotating the first marking arm and the second marking arm about axis of the marking tube to complete the marking operation, replacing the first scriber and the second scriber with a first gas cutting means and a second gas cutting means respectively, and rotating the first marking arm and the second marking arm about axis of the marking tube to complete the cutting operation.

BRIEF DESCRIPTION OF THE DRAWINGS
[008] The foregoing summary, as well as the following detailed description of embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure, however, the disclosure is not limited to the specific methods and device disclosed in the document and the drawing.
[009] The detailed description is described with reference to the accompanying figures. In the figure, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawing to refer like features and components.
[0010] Figure 1 illustrates a device for marking of a pressure hull, in accordance with an embodiment of the present subject matter.
[0011] Figure 2 illustrates a device for marking of a pressure hull, in accordance with another embodiment of the present subject matter.
[0012] Figure 3 illustrates a method for marking and cutting of a pressure hull, in accordance with another embodiment of the present subject matter.
[0013] The figure depicts various embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[0014] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising", “having”, and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Although any devices and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary devices are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0015] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated, but is to be accorded the widest scope consistent with the principles and features described herein.
[0016] As described above, conventionally a jig is used to mark a circle on the surface of the pressure hull. This jig can mark on one side of the pressure hull at a time. After marking on one side of the pressure hull, the jig is need to be removed and then again need to be fitted on other side of the pressure hull. This removal and again fitting the jig incur errors during the marking and a high degree of skills are required to complete the marking on both sides of the pressure hull.
[0017] The present subject relates to a device for simultaneously marking on two sides of a pressure hull on a marine vessel. The device comprises a marking tube, a first marking arm and a second marking arm. The marking tube passes through a hole on the pressure hull. One end of the first marking arm is movably coupled to the marking tube on one side of the pressure hull and other end of the first marking arm comprising a first scriber. One end of the second marking arm is movably coupled to the marking tube on other side of the pressure hull and other end of the second marking arm comprising a second scriber. During operation of the device the first marking arm and the second marking arm are rotatable about the axis of the marking tube and movable along the axis of the marking tube and thereby simultaneously marking on two sides of the pressure hull.
[0018] The device configured in such a way may be used for simultaneously marking on two sides of the pressure hull to facilitate cutting of the pressure hull to install coamings. To operate the device, a hole is made in the pressure hull to insert the marking tube. The marking tube is inserted into the hole so that the marking tube is having substantially similar length exposed on both sides of the pressure hull. The first marking arm is coupled to the marking tube on one side of the pressure hull and the second marking arm is coupled to the marking tube on other side of the pressure hull. The first scriber and the second scriber are movably coupled to the first marking arm and the second marking arm respectively. The first scriber and the second scriber can be moved on the first marking arm and the second marking arm respectively to set a radius of the mark to be made on the pressure hull. The first marking arm and the second marking arm may be moved on the marking tube to make the first scriber and second scriber to touch the respective sides of the pressure hull. Now the first marking arm and the second marking are rotated so that the first scriber and the second scriber make a mark on the respective sides of the pressure hull.
[0019] Hence the present subject matter provides a device for marking on both sides of the pressure hull in a single setup of the device in a reduced time and with less human efforts.
[0020] Referring now to figure 1, a device 100 for marking of a pressure hull 101 is shown. The device 100 may comprise a marking tube 104, a first marking arm 106 and a second marking arm 108. The marking tube 104 passes through a hole 102 on the pressure hull 101. One end of the first marking arm 106 may be movably coupled to the marking tube 104 on one side of the pressure hull 101 and other end of the first marking arm 106 may comprise a first scriber 112. One end of the second marking arm 108 may be movably coupled to the marking tube 104 on other side of the pressure hull 101 and other end of the second marking arm 108 may comprise a second scriber 114. The first marking arm 106 and the second marking arm 108 are rotatable about the axis of the marking tube 104 and movable along the axis of the marking tube 104. During operation of marking the first marking arm 106 and the second marking arm 108 need to be rotated about the axis of the marking tube 104.
[0021] In an implementation of the device 100, a hole 102 is made in the pressure hull 101 to insert the marking tube 104. The marking tube 104 is inserted into the hole 102 so that the marking tube 104 is having substantially similar length exposed on both sides of the pressure hull 101. The first marking arm 106 is coupled to the marking tube 104 on one side of the pressure hull 101 and the second marking arm 108 is coupled to the marking tube 104 on other side of the pressure hull 101. The first scriber 112 and the second scriber 114 are movably coupled to the first marking arm 106 and the second marking arm 108 respectively. The first scriber 112 and the second scriber 114 can be moved along the axis of the first marking arm 106 and the axis of the second marking arm 108 respectively to set a radius of the mark to be made on the pressure hull 101. The first marking arm 106 and the second marking arm 108 may be moved on the marking tube 104 to make the first scriber 112 and second scriber 114 to touch the respective sides of the pressure hull 101. Now the first marking arm 106 and the second marking arm 108 are rotated so that the first scriber 112 and the second scriber 114 make a mark on the respective sides of the pressure hull 101.
[0022] In an embodiment of the present subject matter as shown in figure 2, a holding element 120 may be provided on at least one side of the pressure hull 101 to hold the marking tube 104. The holding element 120 may comprise a platform 122, a C-channel 124, a bearing plate 126 and a bearing 128. The C-channel 124 may be fixed on the platform 122 and the bearing plate 126 may be movably coupled to the C-channel 124. An outer race of the bearing 128 may be fitted to the bearing plate 126 and the marking tube 104 is fitted to an inner race of the bearing 128.
[0023] In an implementation of the device 100, the holding element 120 may provide better accuracy in the marking of the pressure hull 101 with the device of previous embodiment. The holding element 120 may be fitted one on each side of the pressure hull 101 to align with the hole 102 of the pressure hull 101. The marking tube 104 may be passed through the bearing 128 on both sides of the pressure hull 101. Now the bearing plate 126 may be adjusted in longitudinal and transverse direction to align the marking tube 104 for marking on the pressure hull 102. The device 100 configured in this manner provides means to adjust the marking tube 104 even after fixing the holding element 120 to the pressure hull 101.
[0024] In an embodiment of the present subject matter, the holding element 120 may comprise a lock plate 130. The lock plate 130 may be fitted on the bearing plate 126. The marking tube 104 passes through the locking plate 130 and the locking plate 130 locks the axial movement of the marking tube 104.
[0025] The device 100 disclosed in above embodiments of the subject matter is fitted on the pressure hull 101 of a marine vessel to facilitate the cutting of the pressure hull 101. The marking tube 104 is inserted through the hole 102 of the pressure hull. The hole 102 is made in the center of the circular marking to be made on the pressure hull 101. The first marking arm 106 is coupled to the marking tube 104 on one side of the pressure hull 101 and the second marking arm 108 is coupled to the marking tube 104 on other side of the pressure hull 101. The first scriber 112 and the second scriber 114 are movably coupled to the first marking arm 106 and the second marking arm 108 respectively. The holding element 120 is fitted one on each side of the pressure hull 101 such that the marking tube 104 is passed through the bearing 128. The bearing 128 of the holding element 120 holds the marking tube 104 and allows rotation of the marking tube 104 about its own axis. The bearing plate 126 is movable on the C-channel 124 in a longitudinal and transverse direction to align the marking tube 104 on both sides of the pressure hull 101. Once the marking tube 104 is aligned, the bearing plate 126 may be tightened by a nut-bolt means.
[0026] The first marking arm 106 and the second marking arm 108 are independently rotatable about the axis of the marking tube 104. Also the first marking arm 106 and the second marking arm 108 are independently movable along the axis of the marking tube 104. The first scriber 112 and the second scriber 114 are independently movable along the axis of the first marking arm 106 and the axis of the second marking arm 108 respectively. Now by moving the first scriber 112 and the second scriber 114 along the axis of the respective marking arms, the radius of the desired marking mat be set. The first marking arm 106 and the second marking arm 108 may be moved on the marking tube 104 to make the first scriber 112 and second scriber 114 to touch the respective sides of the pressure hull 101. Now the first marking arm 106 and the second marking arm 108 are rotated about axis of the marking tube 104 so that the first scriber 112 and the second scriber 114 make a mark on the respective sides of the pressure hull 101.
[0027] In an embodiment, once the marking on the pressure hull 101 is completed, a further operation of cutting may be performed with the same arrangement of the device 100. To perform the cutting operation, there is no need to remove the device 100 from the pressure hull 101. In the setup of device 100 where marking is done, the first scriber 112 and the second scriber 114 may be replaced with a first cutting means 132 and a second cutting means 134 respectively. In this way the first cutting means 132 will follow the marking made by the first scriber 112 and the second cutting means 134 will follow the marking made by the second scriber 114. Hence the marking and cutting operation of the pressure hull 101 may be completed by setting up the device 100 once and a higher accuracy of the marking and cutting operation may be achieved.
[0028] Now referring to figure 3, a method 200 of marking and cutting on two sides of a pressure hull 101 of a marine vessel is shown. The method 200 comprising steps as following.
[0029] Initially at block 202, a hole 102 may be made on the pressure hull 101 approximately at the center of the final desired marking.
[0030] Further at block 204, a marking tube 104 may be inserted in the hole 102 in such a way to attain a substantially similar portion of the marking on both sides of the pressure hull 101.
[0031] Furthermore at block 206, one end of a first marking arm 106 may be coupled to the marking tube 104 on one side of the pressure hull 101 and at block 208, a first scriber 112 may be coupled removably to other end of the first marking arm 106.
[0032] Furthermore at block 210, one end of a second marking arm 108 may be coupled to the marking tube 104 on other side of the pressure hull 101 and at block 212, a second scriber 114 may be coupled removably to other end of the second marking arm 108.
[0033] At block 214, moving the first scriber 112 on the first marking arm 106 to set the radius of the marking on one side of the pressure hull 101.
[0034] Further at block 216, moving the second scriber 114 on the second marking arm 108 to set the radius of the marking on other side of the pressure hull 104.
[0035] Furthermore at block 218, rotating the first marking arm 106 and the second marking arm 108 about axis of the marking tube 104 to complete the marking operation.
[0036] Now at block 220, replace the first scriber 112 and the second scriber 114 with a first gas cutting means 132 and a second gas cutting means 134 respectively.
[0037] Further at block 222, rotating the first marking arm 106 and the second marking arm 108 about axis of the marking tube 104 to complete the cutting operation.
[0038] Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include the following.
[0039] Some embodiments of the device enable the increased safety of the operator while marking and cutting the pressure hull.
[0040] Some embodiments of the device provide the increased accuracy of the marking and cutting operation on the pressure hull as the device is not removed between the marking and cutting operation.
[0041] Some embodiments of the device reduce time for marking and cutting the pressure hull. The device is not required to be removed in between the marking operation and a cutting operation. After performing a marking operation, in the setup a cutting operation may be performed.
[0042] Some embodiments of the device reduce fatigue to the operator as by use of present subject matter, the device is not required to be removed for cutting operation after a marking operation is completed.
[0043] Some embodiments of the device reduce a requirement of manpower to handle the removal and clamping of the pipe on the device.
[0044] Although implementations for the device 100 have been described in language specific to structural features and/or methods, it is to be understood that the appended claims are not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed as examples of implementation for the device 100.
,CLAIMS:
1. A device (100) for simultaneously marking on two sides of a pressure hull (101) on a marine vessel, wherein the device (100) comprises;
a marking tube (104) passing through a hole (102) on the pressure hull (101);
a first marking arm (106) wherein one end of the first marking arm movably coupled to the marking tube (104) on one side of the pressure hull (101) and a first scriber (112) removably coupled to other end of the first marking arm 106; and
a second marking arm (108) wherein one end of the second marking arm movably coupled to the marking tube (104) on other side of the pressure hull (101) and a second scriber (114) removably coupled to other end of the second marking arm 108, wherein
during operation of the device (100) the first marking arm (106) and the second marking arm (108) are rotatable about the axis of the marking tube (104) and movable along the axis of the marking tube (104) and thereby simultaneously marking on two sides of the pressure hull (101).
2. The device (100) as claimed in claim 1, wherein the first scriber (112) is movable along the axis of the first marking arm (106).

3. The device (100) as claimed in claim 1, wherein the second scriber (114) is movable along the axis of the second marking arm (108).

4. The device (100) as claimed in claim 1, wherein a holding element (120) may be provided on at least one side of the pressure hull (101) to hold the marking tube (104).

5. The device (100) as claimed in claim 4, wherein the holding element (120) comprises;
a platform (122);
a C-channel (124) fitted on the platform (122);
a bearing plate (126) movably coupled to the c-channel (124); and
a bearing (128) fitted to the bearing plate (126) and the marking tube (104) fitted to inner race of the bearing (128), wherein
the bearing plate (126) adjustable in longitudinal and transverse direction to align the marking tube (104) for marking on the pressure hull (102).
6. The device (100) as claimed in claim 4, wherein the holding element (120) comprises a lock plate (130) and the marking tube (104) passes through the lock plate (130).
7. A method (200) of marking and cutting on two sides of a pressure hull (101) on a marine vessel, wherein the method (200) comprising steps of;
making a hole (102) on the pressure hull (101);
inserting a marking tube (104) in the hole (102);
coupling one end of a first marking arm (106) to the marking tube (104) on one side of the pressure hull (104) and coupling a first scriber (112) removably to other end of the first marking arm (106);
coupling one end of a second marking arm (108) to the marking tube (104) on other side of the pressure hull (101) and coupling a second scriber (114) removably to other end of the second marking arm (108);
moving the first scriber (112) on the first marking arm (106) to set the radius of the marking on one side of the pressure hull (101);
moving the second scriber (114) on the second marking arm (108) to set the radius of the marking on other side of the pressure hull (104);
rotating the first marking arm (106) and the second marking arm (108) about axis of the marking tube (104) to complete the marking operation;
replacing the first scriber (112) and the second scriber (114) with a first gas cutting means (132) and a second gas cutting means (134) respectively; and
rotating the first marking arm (106) and the second marking arm (108) about axis of the marking tube (104) to complete the cutting operation.