FIELD OF INVENTION
The present invention relates to an arrangement of bridging the gap
provided between entry side table and exit side scrap table during the up cut
shearing of weld part of coil in cold rolling mills and a process for the same.
BACKGROUND OF THE INVENTION
Up cut link type shear: In this type of shear, the upper blade is fixed and
bottom blade is moved up to cut the strip. This movement is done by a hydraulic
cylinder connected to bottom blade assembly. So, there is a gap provided
between the entry side table and the exit side scrap table for up/down
movement of bottom blade.
Cold Rolling. Mill (CRM) produces (coated or uncoated) cold rolled sheets
as its end product. There are two lines, CGL-1 and CGL-2 for coated cold roll
sheet production.
In Continuous galvanizing line-1 (CGL-1) we have input of Cold Rolled
coils of strip thickness 0.223 to 0.98 mm and width 900 or 1015mm. The weight
of coil will be max of 20t, leading to length in thousands of meters.
The basic purpose of CGL-1 line is to produce galvanized coils (steel coil
coated with zinc to prevent it from rusting) for either corrugation purpose (with
higher hardness) or for box or drum (for grain storage) making process (with
softer hardness). The hardness of coils is changed by the max temp exposed to
coil in furnace.
The CGL-1 line may be broadly divided into Entry, Process and Exit
Sections. As the CGL-1 line is a continuous line, it is necessary that the
processing section may continuously run, while the entry section and exit
sections work in batches to load and unloading those coils respectively.

The following are the process steps followed for any coil in CGL-1.
Uncoiling and Welding:
A coil is first taken to entry side of CGL-1 and loaded on one of the two
present mandrels, while the other mandrel is uncoiling another coil for its
processing. The purpose of mandrel is to support the coil from its inner diameter
while it is uncoiled and the head end of the sheet is taken to the welder. Once
the previous coil is fully over from the other mandrel, and its tail end gets from
mandrel to welder, the tail end stops and waits for the head end to come
towards the welder from a different but a dedicated route for welding. The
welding is done between the tail end of previous coil and head end of new coil to
obtain a continuity of coil presence in the processing section, which starts after
the welder. During this welding, the entry section has to stop for the welding
process, hence to make the processing section continuously running, a buffer
stock of coil is maintained in the looper at entry, which is maintained in advance
of the welding process. This looper gets empty supplying coil to the process
section while the welding process occurs. Once the welding is done, the looper
again gets filled to prepare for next welding.
The coil once welded, will now undergo a continuous process of cleaning,
heating, galvanizing, chromating and branding before getting recoiled again at
exit.
After all the processing are done, the coil is then passed through an exit
looper, a replica of entry looper wherein the buffer sheet is stored to make up
for the time when coil will be cut in exit section. In exit section, once the welded
region comes, the shear operates separating the front coil with the lagging coil.
The front coil meanwhile has been wound on another mandrel which after the
tail end cutting process, will be an independent processed coil to be taken out of

that mandrel and put in storage area. During this entire operation, as the exit
section is stopped for cutting of coil and its separation, the looper is filled to keep
the process section continuous. This filled looper is then emptied when the new
head end is wrapped in to the mandrel to form a new coil and similar process
continues to give continuous galvanizing production.
Concerned Operation
1. Before coil evacuation from the recoiler mandrel, exit section stops for coil
cutting. The exit shear cuts the strip at weld portion then a sample is cut. The
strip tail end, moving from shear to mandrel, is wrapped to form a coil which will
be evacuated.
2. Then head indexing for new coil starts - the strip head end moves
towards recoiler mandrel for wrapping of fresh coil and thereby entangles into
the gap between the shear and scrap table.
3. So, after every coil cutting, a suitable piece of strip is placed over the gap
manually to pass the strip head end, thus avoiding strip head entanglement into
the inbuilt gap at the shear.
4. The gap was provided as per design for the movement of movable up cut
shear. But this does not suit requirement because when head indexing is done,
strip head end gets into the gap and causes exit cutting delays. So, as a
temporary solution, manual placing of strip piece over the gap had been started,
but this practice is hazardous.
Care is to be taken to bridge the gap maintaining the strip pass line in
normal condition, provided it does not obstruct the upward movement of the
movable (bottom) share. Also it should not create any problem for scrap table
open/close movement which is located immediate to the shear.

Hence, there existed a need to make an arrangement to bridge the gap between
entry and exit side table during the shearing of weld part of coil in cold rolling
mills for a continuous production.
OBJECTS OF THE INVENTION
Therefore, it is an object of the invention to propose an arrangement of bridging
the gap provided between entry side table and exit side scrap table during the
up cut shearing of weld part of coil in cold rolling mills and a process for the
same which is capable of bridging the gap so that processing section run
continuously.
Another object of the invention is to propose an arrangement of bridging the gap
provided between entry side table and exit side scrap table during the up cut
shearing of weld part of coil in cold rolling mills and a process for the same
which does not obstruct the upward movement of the moveable bottom shear.
A further object of the invention is to propose an arrangement of bridging the
gap provided between entry side table and exit side scrap table during the up cut
shearing of weld part of coil in cold rolling mills and a process for the same
which does not create any problem for scraptable open/close movement located
immediate to the shear.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig.l.: Shows the shear assembly machine with fixed and moveable shear blade,
entry and exit table before the arrangement of bridging the gap.
Fig.2.: Shows the shear assembly machine with fixed shear blade and moveable
shear blade, entry and exit table and bridging of the gap according to the
invention.

Fig.3.: Shows the spring loaded guiding attachment according to the invention.
Fig.4.: Shows a photograph of the attachment to bridge the gap according to the
invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
Process of Bridging the gap (1) between entry table (4) and exit shear table (6)
is made in order to make the strip pass line continuous and to avoid the
hazardous manual interference of placing a strip (1) manually to bridge the gap
after every cutting. Care is taken so that the arrangement to bridge the gap does
not obstruct the upward movement of the moveable bottom shear (3) and also
does not create any problem for scrap table open/close movement, the scrap
table (6) being located immediate after the shear.
A swing type attachment which is consisted of a curved plate of radius 254mm
the plate having dimension as 3x110x1550mm, two threaded studs of M16xL150
welded on both end of the plate upon which 2 nos. of helical spring is inserted.
Two channels of 70x80x135mm are welded on the lower part of the top frame of
the shear having hole on each at their lower part. Then the rods welded on plate
are inserted into the holes on welded channel and fixed by tightening the two
nuts (M16) on each of them. This is adjusted to the pass line. Thus a spring
loaded mechanical attachment with a supporting plate fixed in top frame of
shear with two supports at both ends maintaining the pass line is disposed to
bridge the gap.
During strip cutting, when moveable shear (3) moves up, the gap bridging plate
is also pushed upward by it simultaneously and while making the cut, it comes
down, the plate also comes to its original position i.e. to the pass line under the
spring force.

Now, as strip head indexing starts, the strip head end passes without any
interruption over this gap bridging plate smoothly.
ADVANTAGES AND BENEFITS
> Long pending problem of strip entangling and folding due to design
constraint, since commissioning, is solved.
> Requires no power in any form: pneumatic, hydraulic or electric.
> No manual involvement in any form for its operation.
> Elimination of line stoppage due to strip head end entangling problem
during coil cutting sequence.
> Almost zero installation cost-the spring attached was a spare spring from
welder of CGL-1. Development of design, its fabrication and installation all
have been done in-house.
> Completely maintenance free as it is a fixed type attachment.

WE CLAIM
1. An arrangement of bridging the gap provided between entry side table
and exit side scrap table during the up cut shearing of weld part of coil in cold
rolling mills and a process for the same, the said arrangement comprising;
a swing type attachment comprising of a curved plate (7);
two threaded studs (8) welded on both end of a plate (11) and resting on
the plate (7);
two springs (9) accommodating the studs (8);
two channels (12) welded on the lower part of the top frame (11) having
holes (13) in each of the channels (12) at their lower part; wherein
two rods welded on plate are inserted into the holes (13) on welded
channel and fixed by tightening the two nuts and studs (8) forming a spring
loaded guiding attachment.
2. The arrangement as claimed in claim 1, wherein the radius of the curved
plate is 254mm and of size 3mmxll0mmxl550mm.
3. The arrangement as claimed in claim 1, wherein the channels are of sizes
70mmx80mmxl35mm.

4. The arrangement as claimed in claim 1, wherein the studs are
M16xl50mm.
5. A process of bridging the gap provided between entry side table and cut
side scrap table during the up cut shearing of weld part of coil in cold rolling
mills, the said process comprising;
starting the strip head indexing;
allowing the strip head end passing over the gap bridging plate; wherein
during strip cutting when moveable shear blade (3) moves up making the
gap bridging plate (7) pushed up and when making the cut while coming down
forces the plate (7) to come down to the pass line with the spring force.

ABSTRACT

The present invention discloses an arrangement of bridging the gap provided
between entry side table and exit side scrap table during the up cut shearing of weld
part of coil in cold rolling mills and a process for the same. The arrangement comprises
of a swing type attachment comprising of a curved plate, two threaded studs (8)
welded on both end.of a plate (11) and resting on the plate (7), two springs (9)
accommodating the studs (8), two channels (12) welded on the lower part of the top
frame (11) having holes (13) in each of the channels (12) at their lower part when two
rods welded on plate are inserted into the holes (13) on welded channel and fixed by
tightening two nuts and studs (8) forming a spring headed guiding attachment.