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:
CAMBERING PROCESS FOR STANDARD GAUGE CATENARY MAINTENANCE VEHICLE SHELL MANUFACTURING

Applicant:
BEML Limited
A company Incorporated in India under the Companies Act, 1956
Having address:
BEML Soudha, 23/1, 4th Main,
Sampangirama Nagar, Bengaluru - 560 027,
Karnataka, India

The following specification particularly describes the invention and the manner in which it is to be performed.
CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present invention claims priority from Indian patent application numbered IN 202041025786 filed on 18th June 2020.

TECHNICAL FIELD
[002] The present subject matter described herein, in general, relates to a cambering process for manufacturing a shell of a standard gauge catenary maintenance vehicle (SG CMV), and more specifically to the cambering process for an underframe assembly of the standard gauge catenary maintenance vehicle.

BACKGROUND OF THE INVENTION
[003] Cambering is a deflection at the centre of a beam which is usually applied to structural steel beams/girders to compensate for de?ections due to permanent dead load and live loads. Traditionally, the cambering is achieved by application of heat (heat cambering) or force (cold cambering). Heat cambering is time-consuming and costly process. Controlling heat transfer and restricting permanent deformation is very difficult task in a big structure using heat cambering. Cold cambering is faster and is most commonly used by manufacturers. Cold cambering and heat cambering processes have different mechanism of bending arrangements.

[004] The conventional cambering process used for manufacturing of rolling stocks fails to provide the required cambering of the underframe assembly. Hence, there is requirement of new system to be developed for cambering process of the underframe assembly of SG CMV shell. This new system provides desired camber to the underframe assembly of SG CMV shell.

OBJECTS OF THE INVENTION
[005] Main objective of the present invention is to provide initial camber setting having predetermined value, greater than the required final cambering to an integrated underframe and girder assembly.

[006] Another object of the present invention is to establish a cambering process for integrated underframe and girder assembly of SG CMV project by using proposed set up configured of I section rails, chain pulley blocks, theodolites, hydraulic jacks and tie rods on standard gauge track.
SUMMARYOF THE INVENTION
[007] Before the present process are described, it is to be understood that this application is not limited to the particular machine or an apparatus, and methodologies described, 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 cambering process for underframe of SG CMV, 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.

[008] The present subject matter described herein, in general, relates to a cambering process for a standard gauge catenary maintenance vehicle (SG CMV) shell manufacturing comprising steps of, marking an underframe of the vehicle shell with a pointed punch/permanent marker, at predetermined positions based on a selected rail gauge wherein the rail gauge may be a meter gauge, a narrow gauge or a broad gauge , then mounting plurality of “A” supports on a track at predetermined distance from each other, mounting the underframe in upside down position on the said “A” supports wherein the underframe may be configured with plurality of headstocks and plurality of body bolsters wherein the chain pulley blocks are hooked up to the I section rails fastened to the track and the headstocks, mounting plurality of hydraulic jacks for operating chain pulley blocks, mounting a pre cambered girder on the underframe wherein the center line of the pre cambered girder may be configured to coincide with the center of underframe and a tack welding of the girder to the underframe may be carried out, pulling/rising of the underframe along with the girder in order to achieve negative cambering of predefined value, greater than a final required camber value, releasing the chain pulley blocks and determining the cambering values, a full welding may be performed by clamping the underframe, reversing the underframe along with the girder on “A” supports, releasing the chain pulley blocks and checking the final cambering values within the predetermined limit wherein if the required cambering is not achieved, repeating the above-mentioned cambering process in reverse direction.

[009] Further, Furthermore, the cambering of SG CMV shell (100) is configured to be achieved by cold bending process. Further, the cambering values are configured to change based on the bogie size and selected rail gauge, and the achieved camber values are configured to be determined by theodolite instrument. Furthermore, the longitudinal beams (102) and the girders (120) of the said invention are configured to be manufactured with IRSM 41 material.

BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing summary, as well as the following detailed description of embodiments, is better understood when read in conjunction with the appended drawing. 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 apparatus disclosed in the document and the drawing:

[0011] The detailed description is described with reference to the accompanying figure. 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.

[0012] Figure 1 illustrates an isometric view of SG CMV Shell.

[0013] Figure 2 illustrates a schematic of an underframe of conventional coaches having two parallel longitudinal beams.

[0014] Figure 3 illustrates a schematic of cambered underframe of SG CMV coach having two parallel Longitudinal beam and pre cambered girder assembly that welded to both beams.

[0015] Figure 4 illustrates a schematic of a track with center line marking.

[0016] Figure 5 illustrates a schematic of various center lines of an underframe of vehicle.

[0017] Figure 6 illustrates a schematic of an underframe placed on “A” stand.

[0018] Figure 7A illustrates a schematic of initial camber setting of SG CMV underframe structure without girder assembly.
[0019] Figure 7B illustrates a schematic of initial camber setting of SG CMV underframe structure with girder assembly.

[0020] Figure 8 illustrates a schematic of coinciding of a girder and an underframe assembly center line and isometric view of SG CMV underframe.

[0021] Figure 9 illustrates a schematic of initial camber setting of an underframe with girder assembly.

[0022] Figure 10 illustrates a flow chart of a cambering process for underframe assembly of SG CMV.

[0023] 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.

[0024] REFERRAL NUMERALS:
Element Description Reference Numeral
SG CMV Shell 100
Underframe 110
Girder 120
Cabin 130
Body Bolster 140
Headstock 150
Bolster center 142
Longitudinal Beams 102
27 +5/-2 mm Cambered Underframe 114
27 +5/-2 mm Cambered Girder 124
Railway Track 160
“A” Stand 170
54 mm Cambered Underframe 112
54 mm Cambered Girder 122

DETAILED DESCRIPTIONOF THE INVENTION
[0025] 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. Although any systems 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, systems and methods are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.

[0026] 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.

[0027] Cambering is being carried out in the underframe assembly (110) for a shell (100) manufacturing. The required cambering of the underframe (110) assembly may not be achieved using conventional cambering process used for manufacturing of rolling stocks. In an absence of data relating to loads and deformations, the process is based on trial and error and relies mainly on manufacturer’s skills, expertise and experience. The proposed cambering process of the underframe (110) of the shell (100) is indigenously designed, developed and validated which provides ease to the manufacturer in performing cambering process.

[0028] Referring now to figure 1, the shell (100) manufactured by the proposed cambering process is shown. In one of the embodiments, the shell (100) may be SG CMV shell. The SG CMV shell (100) comprises two cabins (130) mounted at each end of the underframe (100). Further, the underframe (100) may be mounted along with a girder (120) on a track (160).

[0029] Referring now to figure 2, the underframe (110) of coaches comprising two parallel longitudinal beams (102) is shown wherein the said longitudinal beams (102) may be connected by cross members. The longitudinal beams (102) may be welded to multiple structures as shown in figure and finally a trough floor may be mounted on the said structures to form the underframe (110). In one of the embodiments, length of the parallel beams (B) may be 21025 mm, distance between the two parallel longitudinal beams (D) may be 2896 mm and height of each longitudinal beam (T) may be 460 mm. The above-mentioned dimensions may be changed based on a size of the SG CMV shell (100). Further, the underframe (110) comprises at least two body bolsters (140) mounted along Y axis as shown in figure 2 wherein the body bolsters (140) may be mounted for support and for reference while performing cambering. Furthermore, two headstocks (150) may be mounted at each end of the underframe (110).

[0030] Referring now to figure 3, cambered underframe (114) of SG CMV coach having two parallel longitudinal beams (102) and cambered girder assembly (124) is welded to both longitudinal beams (102) are shown. The initially cambered underframe (112) may have the greater cambering value than of the actual required cambering value. The underframe (112) is configured to be mounted and marked for further processing based on selected rail gauge or a standard gauge wherein the standard gauge may be a narrow gauge, a meter gauge or a broad gauge.

[0031] The detailed steps for carrying out cambering process for the underframe (110) of SG CMV shell (100) are as follows-
i. Marking a center line of a track (160) as shown in figure 4.
ii. Marking the center line of the underframe (110) from the headstock (150) to headstock (150) along (X-X), marking the center line of the body bolster (140) along (Y-Y) on 2 axis and marking the center of the underframe (110) from the longitudinal beam (102) to longitudinal beam (102) along (Z-Z) with a pointed punch/permanent marker as shown in figure5.
a. Further, two “A” supports (170) may be mounted on the track (160). In an embodiment, the “A” supports (170) may be mounted at a distance of 14783 mm i.e. one each at both body bolster center line locations along (Y-Y center line) as shown in figure5. Another two “A” supports (170) may be mounted closer to extreme ends of the girder assembly (120). In an embodiment, the said “A” supports may be mounted at an approximate distance of 2669.5 mm from Y-Y center line.
iii. Mounting the underframe (110) on “A” supports (170) such that the headstocks (150) face upward direction as shown in figure6.
iv. Starting cambering process by using I section rails and a chain pulley block wherein the I section rails may be mounted by welding as described below
a. Welding total 4 (2+2) I section rails on either of each body bolster (140) along (Y-Y Axis) on the track (160) in such a way that it should be pulled by a chain pulley block.
b. Welding total 6 (3+3) I section rails on the track (160) at the center of the underframe (110) along (Z-Z Axis) and at a distance of 1 meter from Z-Z axis on each track to pull or rise the underframe (110) with girder (120).
c. Welding total 4 (2+2) I section rails at the extreme end of each head stock (150) on either side of track (160) to pull /rise the headstock (150).
v. Cambering of underframe structure along the center line of underframe (110) with reference to body bolster (140) center by cold bending process as shown in figure7A. In an embodiment, the camber value may be 54 mm.
vi. Pre cambered girder (122) having predetermined cambering value may be maintained in individual girder assembly (122) with reference to its ends. In an embodiment, the pre cambered girder may have 27+5/-2 mm cambering value.
vii. Mounting the pre cambered girder (122) on the underframe (110) such that marking of the center line of the cambered girder (124) coincides with the center of underframe assembly (112) as shown in figure7B.
viii. Mounting two theodolite instruments on either side of the longitudinal beams (102) at a predetermined distance wherein, the theodolites may determine the achieved cambering values.
ix. Locking the chain pulley block with the support of each body bolster (140) to the I section rails welded on the track (160) on either side of the body bolster (140) wherein the chain pulley block may be 8 (4+4) in total and weighs 3 ton.
x. The chain pulley block is hooked up to each head stock (150) on either side with the support of hook wherein the chain pulley block may be 4 (2+2) in total and weighs 1.5 ton.
xi. Further, the chain pulley block is hooked up on each girder (124), one at center along (X-X Axis) and four (2+2) on either side of the center (1 meter apart from XX Axis) of the girder (124) on each track (160) together with girder (124). In an embodiment, the center may be brought down to 54 mm negative cambering (refer figure 9) by operating the chain pulley block on either side of track (160) wherein the value of initial negative camber may be configured to change based on the bogie size, selected rail gauge and the required camber value.
xii. In an embodiment, the bolster area may be brought down to “0” cambering and girder ends (at 4 corners) may be brought down to 29 mm negative cambering with reference to “0” wherein the value camber at girder end may be configured change based on the bogie size and selected rail gauge.
xiii. Further, tack welding of girder assembly (124) to underframe (112) may be done and then locating tie rods to ensure parallelism and locating the girder assembly (124) by passing the center line and considering center of head stock (150), the body bolster (140) and the underframe (112) center line wherein the tie rods are mounted below the underframe (110) to support the underframe from distortion.
xiv. Pulling/rising the chain pulley blocks with the help of hydraulic jacks to perform cambering.
a. Positioning a vertical gusset from the girder (124) to the underframe (112) on either side, multiple weld pass of root layer is established intermittently to avoid weld distortion and twisting on either side of each girder. Finally filling the gap and finish the process.
xv. Releasing the chain pulley block and finally checking the camber for required value. In an embodiment, the required camber value may be 27+5/-2 mm. If the cambering value is not found within the designed value, initial cambering setting is re-established as per process step nos. xi & xii as shown in figure9 to strengthen the longitudinal beam (102) from the headstock (150) to towards girder assembly (124) to a length of 7.7 meters at 4 places. The camber value may be less than the provided initial camber value as the underframe (112) may try to regain its original dimensions.
xvi. The angle assembly is tack welded, a root gap is passed to avoid the distortion intermittently and full welding is carried out. The longitudinal beam (102) is strengthened from the headstock (150) end sill towards the girder of length 6.7 meters up to the 1st vertical gusset of girder assembly on all sides.
xvii. Reversing the underframe (112) along with the girder (124) and mounting on “A” stand.
xviii. Clamping the body bolster area by chain pulley block to make “0” cambering wherein the chain pulley block may be 3 ton and total 8 (4+4) in number.
xix. Fixing one each of 3ton of the chain pulley block at the center of the underframe with the girder to achieve 54mm positive camber such that a hydraulic jack to be mounted at the bottom center of girder to arrest the dimension.
xx. Ensuring cambering of the underframe on either side by adding shims temporarily to achieve cambering.
xxi. Lay trough floor & complete cabin erection on either side.
xxii. Welding side support assembly on all the longitudinal beam (102) behind the cabin (130) extended towards the underframe center in camber condition.
xxiii. Welding side support assembly in between side support assembly on longitudinal beam (102)in camber condition at 2 places.
xxiv. Releasing all the chain pulley blocks and check for final cambering values of shell.
[0032] The present invention relates to a cambering process for a standard gauge catenary maintenance vehicle (SG CMV) shell (100) manufacturing comprises the steps of, marking an underframe (110) of the vehicle shell (100) at predetermined positions based on a selected rail gauge, mounting plurality of “A” supports on a track (160) at predetermined distance from each other, mounting the underframe (110) in upside down position on the said “A” supports wherein the underframe (110) is configured with plurality of headstocks (150) and plurality of body bolsters (140), mounting plurality of chain pulley blocks and plurality of I section rails wherein the I section rails are configured to be fastened to the track (160) at predetermined locations and the predetermined number of chain pulley blocks are hooked up to the I section rails and the headstocks (150), mounting plurality of hydraulic jacks for operating the chain pulley blocks, mounting a pre cambered girder (122) on the underframe (110) wherein the center line of the pre cambered girder (122) is configured to coincide with the center of underframe (110), a tack welding of the girder (122) to the underframe (110) is performed and a vertical gusset is configured to be positioned from the girder (122) to the underframe (112), pulling/rising of the underframe (110) along with the girder (122) to achieve negative cambering of predefined value, greater than a final required camber value, releasing the chain pulley blocks, a full welding is configured to be performed by clamping the underframe (112), reversing the underframe (112) along with the girder (122) on “A” supports and checking the final cambering values within the predetermined limit wherein if the required cambering is not achieved, repeating the above-mentioned cambering process in reverse direction.
[0033] Further, a pointed punch/permanent marker is configured for marking of the underframe (110), wherein the underframe (110) marking is configured from the headstock (150) to headstock (150) along (X-X) axis, marking the center line of the body bolster (140) along (Y-Y) axis and marking the center of the underframe (110) from the longitudinal beam (102) to longitudinal beam (102) along (Z-Z) axis. Furthermore, the cambering of SG CMV shell (100) is configured to be achieved by cold bending process. Further, the cambering values are configured to change based on the bogie size, selected rail gauge and final required camber values wherein, the achieved camber values are configured to be determined by theodolite instrument. Furthermore, the longitudinal beams (102) of the underframe (110) and the girders (120) of the said invention are configured to be manufactured with IRSM 41 material.
,CLAIMS:
1. A cambering process for a standard gauge catenary maintenance vehicle (SG CMV) shell (100) manufacturing comprises the steps of,
marking an underframe (110) of the vehicle shell (100) at predetermined positions based on a selected rail gauge;
mounting plurality of “A” supports (170) on a track (160) at predetermined distance from each other;
mounting the underframe (110) in upside down position on the said “A” supports (170) wherein the underframe (110) is configured with plurality of headstocks (150) and plurality of body bolsters (140);
mounting plurality of chain pulley blocks and plurality of I section rails wherein the I section rails are configured to be fastened to the track (160) at predetermined locations and the predetermined number of chain pulley blocks are hooked up to the I section rails and the headstocks (150);
mounting plurality of hydraulic jacks for operating the chain pulley blocks;
mounting a pre cambered girder (122) on the underframe (110) wherein the center line of the pre cambered girder (122) is configured to coincide with the center of underframe (110);
a tack welding of the girder (122) to the underframe (110) is performed and a vertical gusset is configured to be positioned from the girder (122) to the underframe (112);
pulling/rising of the underframe (110) along with the girder (122) to achieve negative cambering of predefined value, greater than a final required camber value;
releasing the chain pulley blocks;
clamping the underframe (112) and a full welding is configured to be performed;
reversing the underframe (112) along with the girder (122) on “A” supports; and
checking the final cambering values within the predetermined limit wherein if the required cambering is not achieved, repeating the above-mentioned cambering process in reverse direction;
2. The cambering process for a standard gauge catenary maintenance vehicle (SG CMV) shell (100) manufacturing as claimed in claim 1, wherein a pointed punch/permanent marker is configured for marking.

3. The cambering process for a standard gauge catenary maintenance vehicle (SG CMV) shell (100) manufacturing as claimed in claim 1, wherein the underframe (110) is configured with the body bolsters (140) located at predetermined position and the headstocks (150) at two ends of the underframe (110).

4. The cambering process for a standard gauge catenary maintenance vehicle (SG CMV) shell (100) manufacturing as claimed in claim 1, wherein the underframe (110) marking is configured from the headstock (150) to headstock (150) along (X-X) axis, marking the center line of the body bolster (140) along (Y-Y) axis and marking the center of the underframe (110) from the longitudinal beam (102) to longitudinal beam (102) along (Z-Z) axis.

5. The cambering process for a standard gauge catenary maintenance vehicle (SG CMV) shell (100) manufacturing as claimed in claim 1, wherein the cambering of SG CMV shell (100) is configured to be achieved by cold bending process.

6. The cambering process for a standard gauge catenary maintenance vehicle (SG CMV) shell (100) manufacturing as claimed in claim 1, wherein the initial cambering is configured to be 54 mm negative cambering at the center of the underframe (110), “0” cambering at body bolster area and 29 mm negative cambering at the girder’s end and the final required cambering is 27+5/-2 at the center of the underframe (110).

7. The cambering process for a standard gauge catenary maintenance vehicle (SG CMV) shell (100) manufacturing as claimed in claim 1, wherein the value of initial negative camber and the camber at girder end are configured to change based on the bogie size, selected rail gauge and the final required camber value.

8. The cambering process for a standard gauge catenary maintenance vehicle (SG CMV) shell (100) manufacturing as claimed in claim 1, wherein the longitudinal beams (102) of the underframe (110) are configured to be connected by plurality of cross members.
9. The cambering process for a standard gauge catenary maintenance vehicle (SG CMV) shell (100) manufacturing as claimed in claim 1, wherein the longitudinal beams (102) and the girders (120) are configured to be manufactured with IRSM 41 material.

10. The cambering process for a standard gauge catenary maintenance vehicle (SG CMV) shell (100) manufacturing as claimed in claim 1, wherein the achieved camber values are configured to be determined by theodolite instruments.