This invention relates to an apparatus and a method for changeover of unwinding
rolls of web material or fabric is disclosed. The apparatus and method is
particularly well suited for unwinding webs material on high speed bag forming
5 machines.
Background Of Invention
In the production of many packaging products, such as sacks and block bottom
bags, plastic film or flexible woven packaging webs are typically formed in a
10 large roll. These large rolls are unwound for conversion operations, such as sack
making or block bottom bag making.

With the increase in bag forming speed, the high-speed unwinding and further
processing web is challenging due to winding quality of rolls. Unwinding of such
15 rolls in a fast and efficient changeover process can also be problematic. For
instance, in many traditional operations, web rolls are unwound one roll at a time.
After a web roll is unwound, the machine is stopped for the removal of the core
and deployment of a new web roll. The downtime associated with web roll
changeover creates a substantial reduction in total available run time that reduces
20 the maximum output that can be obtained from a conversion line. Therefore, there
is need to develop an apparatus and a system for reducing the roll changeover
time and thereby increasing efficiency of conversion line.
Many prior arts describe different kinds of unwinding system and techniques for
25 changing web roll.
As an example of conventional unwinding apparatus for fabric web rolls is
disclosed in GB 2021520 B (‘520). The patent (‘520) relates to the unwinding
stand for a plurality of the fabric web roll with a lifting mechanism by means of
30 which individual fabric roll may be lifted upon their support blocks provided on
3
the two sides of the unwinding stand. The invention (‘520) comprises of system
where the arrangement of the rolls are opposite to each other such that if first roll
is placed in-line with the bag making machine then to make second roll in-line
with the machine the whole apparatus has to be turned which eventually increases
5 the downtime. The further drawback of the invention (‘520) is the use of
pneumatic cylinder which may eventually hamper the continuous motion of the
roll if there is a lag/drop in air pressure.
Therefore, there is need to develop an apparatus and a system for reducing the roll
10 changeover time and at the same time increasing the efficiency of conversion line.
The present invention overcomes the drawbacks unwinding web roll for bag
making machine as well as changing roll efficiently to reduce overall downtime.
Objects of Invention:
15 The main objective of present invention is to provide an apparatus and method
which substantially reduce changeover time.
A further objective of present invention is to provide a web roll changeover
system that is efficient.
20
Another objective of the present invention is to provide a web roll changeover
system that allows efficient changeover between different width web rolls.
Another objective of the present invention is to provide a web roll changeover
25 system that is capable of unwinding different type of web roll material.
Brief Description Of Figures:
Figure 1 shows perspective view apparatus of invention
Figures 2 and 2a show perspective view of slidable frame
30 Figure 3 shows apparatus of invention with fabric roll and fabric path
4
Figure 4 shows the press assembly and its parts
Figure 5 shows the locking assembly and its parts
Figures 6-A to 6-L illustrate the various steps of the method of the invention as
follows:
5 Figure 6-A shows sliding direction of carrier platform of the apparatus
Figure 6-B shows rolling of replacement roll over carrier platform
Figure 6-C unlocking the carrier platform and sliding roll towards roll shaft
Figure 6-D shows sliding roll shaft downwards to make it concentric with the axis
of roll
10 Figure 6-E shows sliding roll onto the roll shaft up to the distance piece
Figure 6-F shows unwinding of fabric over guide rods
Figure 6-G shows unwinding of fabric completed over guide rod and waiting for
active roll to finish
Figure 6-H shows lowering of press assembly and cutting the fabric
15 Figure 6-I shows pasting replacement fabric with the existing fabric
Figure 6-J shows raising press assembly and unwinding of fabric begins
Figure 6-K shows lowering roll shaft to replace the near to empty roll onto the
carrier platform
Figure 6-L shows removal of the near to empty roll from the apparatus
20
Summary Of Invention:
The apparatus and method as disclosed herein for changeover of unwinding rolls
of web material is designed to reduce downtime involved in changing the
unwinding roll. The apparatus of the invention has one operational web roll
25 unwinding station or simply an unwinding station, and a standby web roll
platform or simply a replacement roll platform. At the unwinding station, there
takes place the unwinding activity where the web roll is unwound for supply to
the downstream processing station. While one roll (the active roll) is being thus
unwound, at the another platform a replacement roll is prepared for eventual
30 unwinding. When the active roll is to be replaced, the fabric is severed from the
5
active roll, the replacement roll is positioned for unwinding, the fabric from the
replacement roll is joined with the severed fabric from the active roll, so that
unwinding of fabric from the replacement roll can continue without much
interruption. The replacement roll now becomes the active roll.
5
When the fabric needs to be replaced, the same process is repeated. When the
fabric from the replacement roll is different from the fabric of the active roll –
either in its width, denier, or type – suitable measures are taken so that the joining
of the replacement fabric with the fabric being unwound is such that the
10 downstream processes can continue with least possible interruption. The only
downtime during the unwinding process is thus the time it takes to sever the fabric
from the active roll and the time taken to position the replacement roll for
unwinding and joining the replacement fabric onto the fabric of the active roll.
15 Moreover, since the fabric preparation is carried out simultaneously with
unwinding of the active roll the total downtime is significantly reduced.
Furthermore, the time taken to position the replacement roll into the unwinding
position is also greatly reduced in the system and method of the invention – the
significant amount of which also overlaps the unwinding process, thereby further
20 reducing the overall downtime.
List of Parts:
1. Main frame
2. Base members
25 3. Right arm
4. Left arm
5. Joining element
6. First guide roller
7. Second Guide roller
30 8. Third guide roller
6
9. Press assembly
9A. Press arm
9B. Overlaying arm
9C. Handle
5 9D. Pivot
10. guide rail motor of active roller shaft
10A. Guide rail motor of replacement roller shaft
11. Slidable frame
12. First guide rod
10 12A. Third Guide rod
13. Second guide rod
13A. Fourth Guide rod
14. Connecting rod
15. Bracket
15 16. Front rail guide
16A. Back rail guide
17. Inactive roll shaft
18. Active roll shaft
19. Distance piece
20 20. Drive motor
21. Support wall for roll shaft
22. First base plate
22A. Second base plate
23. First vertical guide rail
25 23A. Second vertical guide rail
24. First support platform
24A. Second support platform
25. First carrier platform
25A. Second carrier platform
30 26. Locking assembly
7
26A. Press element
26B. Spring
26C. Hinge
26D. Projection
5 26E. Cavity
26F. Position
27. First rail guide
27A. Second rail guide
28. Unwinding Fabric on active roll
10 28A. Replacement fabric on replacement roll
29. Active roll
30. Replacement roll
31. Unwinding position
32. Drive unit
15 33. First vertical level adjustment mechanism
33A. Second vertical level adjustment mechanism
34. Operator
Detail Description Of Invention:
20 The apparatus and the method of invention for changeover of an unwinding roll of
fabric is disclosed.
Figure 1 shows an apparatus of present invention, which comprise a main frame
(1), a slidable frame (11) and at least two support platforms (24, 24A) for fabric
25 rolls (29, 30)where main frame (1) also comprises a right arm (3) and a left arm
(4) which are connected by at least one joining element (5) so as to make the main
frame (1) sturdy. A first guide roller (6), a second guide roller (7), and a third
guide roller (8) are mounted on the right arm (3) and left arm (4) such that they
guide the unwinding fabric (28) unwinding from the active roll (29). The first
30 guide roller (6), second guide roller (7), and third guide roller (8) allow a change
8
in the direction of the fabric (28, 28A) as it unrolls from the respective rolls (29,
30), as shown in Figure 3.
A press assembly (9) is provided to apply pressure on the unwinding fabric (28)
5 so that during roll changeover from the active roll (29) to the replacement roll (30)
carrying replacement fabric (28A), the fabric (28) is easily accessible to an
operator (34) and can be cut in the a direction transverse to the fabric travel
direction without being deviated from its initial position. The main frame (1) may
be in the form of a structure such that it is supported by the base members (2),
10 which are also a part of the main frame (1), affixed firmly to the ground onto
which the slidable frame (11) slides.
As shown in Figure 2, the slidable frame (11) which slides over the main frame
(1) comprises a support wall (21) for roll shafts (17, 18) and at least two members
15 – a front rail guide (16) and a back rail guide (16A) – serving as rail guides for
slidable frame (11). The front and back rail guides (16, 16A) are slidably mounted
over the base members (2) of the main frame (1). The support wall (21) is fixedly
connected to the front and back rail guides (16, 16A) using any mechanical means
such as welding or bolting or screwing to form a rigid part. Rail guides (16,16A)
20 may be of any type to provide smooth sliding motion to the frame (11) which can
be achieved with linear bearing /bush or any mechanical means known to person
skill in art.
Further, the slidable frame (11) also has on its one side a first guide rod (12) and a
25 second guide rod (13). On its other side, the slidable frame (11) has a
corresponding pair of guide rods, namely a third guide rod (12A) and a fourth
guide rod (13 A). The first and third guide rods (12, 12A) and the second and
fourth guide rods (13, 13A) are connected to each other with connecting rods (14)
to make the arrangement robust. The guide rods (12, 13, 12A, and 13A) are
30 provided to facilitate the direction change of the fabric (28, 28A) referred to
9
earlier. The guide rod assembly comprising the guide rods (12, 13, 12A, 13A)
interconnected by connecting rods (14) is affixed to the slidable frame (11) by a
bracket (15) using any mechanical arrangement such as welding, bolting or
screwing.
5
The slidable frame (11) further constitutes at least one pair of roll shafts referred
to earlier – an active roll shaft (18) and an inactive roll shaft (17) – provided to
mount the fabric rolls (29, 30) respectively. The active roll shaft (18) and inactive
roll shaft (17) are arranged on opposite faces of the support wall (21). Depending
10 on the size of the rolls (29, 30), the vertical level of the roll shafts (17, 18) during
their working positions, i.e. the position in which they are mounted at the time of
fabric replacement, may vary. This is achieved by providing a vertical level
adjustment mechanism (33) which helps the roll shafts (17, 18) to adjust their
vertical level. The vertical level adjustment mechanism (33) comprises a first base
15 plate (22) provided on which the roll shaft (18) for active roll (29) is mounted, and
a pair of first vertical guide rails (23) that are affixed to the support wall (21) and
over which the first base plate (22) slides vertically. The vertical sliding
movement of the first base plate (22) is controlled by a first guide rail motor (10)
as shown in Figure 2A. A similar arrangement is provided for the inactive roll
20 shaft (17) – a second base plate (22A) which is slidable by a second guide rail
motor (10A) on second vertical guide rails (23A) as shown in Figure 2.
Further, a set of sensors (no shown) is provided to determine the position of the
movement of the roll shafts (17, 18) in upwards and downwards direction. The
25 motors (10, 10A) are provided with braking arrangement so as to hold the roll
shafts (17, 18) at their desired levels in a stationary condition.
Since the width of the fabric is variable, the position of the rolls (29, 30) along the
roll shafts (17, 18) is also variable. A distance piece (19) is provided on each of
30 the roll shafts (17, 18) to act as a barrier or a stopper for the active roll (29) or
10
replacement roll (30) so that the rolls (29, 30) are aligned centrally to the
respective roll shaft (17, 18). The distance piece (19) can be moved over roll
shafts (17, 18) and its position can be locked according to the width of the roll
(29, 30) loaded on the roll shafts (17, 18).
5
In one of the embodiments, support wall (21) can be made from multiple
structural members or can be made from a single block which is sturdy enough to
bear the weight of the roll shafts (17,18) as well as that of the active roll (29) and
the replacement roll (30).
10
In another embodiment, the front and back rail guides (16, 16A) may be linear
members with a tubular or round cross section, or any kind of structural member
which can smoothly slide over the base members (2). The length of the front and
back guide rails (16, 16A) may be different from each other. One of the said guide
15 rails (16, 16A) comprise a drive unit (32) to drive the slidable frame (11) by a
drive motor (20) to and fro as shown in figures 2 and 2A. The direction of motion
is shown in Figures 2 and 2A with a dashed arrow.
The activity of mounting the rolls (29, 30) onto the respective roll shafts (18, 17)
20 requires that the rolls (29, 30) are brought into the vicinity of the respective roll
shafts (18, 17) and then lifted up so that their centre hole is aligned with the
respective roll shafts (18, 17). Following this, at appropriate stages of the
changeover operation, the rolls (29, 30) are moved laterally so as to slide them
onto the respective roll shafts (18, 17). During the mounting operation of the rolls
25 (29, 30) onto the respective roll shafts (18, 17), the said rolls are supported on
respective support platforms (24, 24A): a first support platform (24) for the active
roll (29) and a second support platform (24A) for the replacement roll (30). The
support platforms (24, 24A) are firmly affixed to the ground by any kind of
mechanical means such as bolting or grouting or clamping and are aligned such
11
that the corresponding roll shafts (18, 17) are concentric to each other facing
opposite to the support wall for roll shaft (21).
Both the support platforms for roll (24A, 24) can be of identical construction. The
5 mounting operation of the rolls (29, 30) also involves their lateral movement
which is facilitated by respective carrier platforms: a first carrier platform (25) for
the active roll (29) and a second carrier platform (25A) for the replacement roll
(30). The carrier platforms (25, 25A) are slidable over the respective support
platforms (24, 24A) with the help of respective pairs of rail guides – a pair of first
10 rail guides (27) and a pair of second rail guides (27A) – that are affixed to
respective support platforms (24, 24A). A locking assembly (26) is provided to
lock the slidable carrier platforms (25, 25A) at the position (26F) so that the
replacement roll (30) can be mounted over it without any mechanical movement.
15 Figure 3 shows the apparatus with an active roll (29) and a replacement roll (30)
wherein the unwinding fabric (28) is being unwound from the active roll (29). It
also shows with a dashed arrow the direction of feeding of the unwinding fabric
(28). The replacement roll (30) is shown in standby position over the second
carrier platform (25A) slidably supported by the second support platform (24A).
20 Fabric being unwound may need replacing for one of many reasons such as the
active roll (29) coming to an end of unwinding fabric (28) or change in type of
fabric (denier, gsm, print/colour, fabric width) being necessary.
Figure 4 shows the press assembly (9) which comprises at least one pair of press
25 arms (9A) which are connected together by an overlaying arm (9B). A handle
(9C) is provided to move the press assembly manually towards and away from the
unwinding fabric (28) about a pivot (9D). Such motion can be achieved by a hinge
mechanism or by bush and pin arrangement to swing the press assembly (9) about
an axis. During roll changeover, the unwinding fabric (28) of the active roll (29) is
30 held in place under pressure by the press assembly (9) before cutting so that the
12
unwinding fabric (28) does not deviate from its present condition. The press arm
(9A) can be metallic or non-metallic and of which one end comprises of a handle
(9C) and another end pivot (9D). Further, the overlaying arm (9B) can also be
metallic or non-metallic of enough strength to press the unwinding fabric (28) and
5 restricts its movement.
Figure 5 shows the locking assembly which comprises press element (26A),
spring element (26B) and a hinge (26C) wherein during the process of the
preparation of the replacement roll (30), the first/second carrier platform (25/25A)
10 is made to slide over first/second support platform (24/24A) to a position A. As
soon as the first/second carrier platform (25/25A) reaches the position A, the
projection (26D) gets inserted into the cavity (26E) and locks the position of
first/second carrier platform (25/25A). Locking is done so that first/second carrier
platform (25/25A) does not move while loading of replacement roll (30). When
15 the loading of the replacement roll (30) is done, operator (34) presses the press
element (26A) manually and thereby releases the projection (26D) from cavity
(26E). The movement of press element (26A) to and fro is governed by hinge
(26B) and a spring (26B), the said spring (26B) exert a back force so that after
release, press element (26A) assumes its original position.
20
As an example, a bag making machine which is running at a speed of 120 meters
per minute and having bag output of 120 bags per min using conventional
unwinding system. It was observed during roll changeover the machine stops and
operator takes 5 mins to change the roll and again start the machine and in such
25 case, there is a production loss for 5 minutes i.e. of 600 bags. In the same machine
when operator uses the inventive unwinding system wherein it was observed that
the roll changeover time, the down time is reduced to 2 minutes, thus reducing
production loss to 240 bags from 600 bags.
13
Figures 6-A to 6-L show inventive method of roll changeover from an active roll
(29) to a replacement roll (30) such that the down time during the changeover
operation is minimised. The method to change from active roll (29) to a
replacement roll (30) involves following steps:
5 a. an operator (34) inspects the fabric for suitability for making the objects
and prepares the starting portion of the fabric (28A) of the replacement roll
(30) for joining with the fabric (28) of the active roll (29). The top layers
of rolled fabric of the replacement roll (30) may have become damaged
during transport/handling. These layers may need removing before
10 unwinding. The operator thus ‘prepares’ the replacement roll (30) for
unwinding with its visible end ready for joining with the fabric that is
being unwound. This activity may be carried out near the unwinding
station or at any place suitable for this activity.
b. before loading the replacement roll (30) onto the second carrier platform
15 (25A), the operator slides (sliding movement shown by a dashed arrow in
Figure 6-A) the second carrier platform (25A) to a position A shown by a
solid line in Figure 6-A and locks it.
c. the replacement roll (30) is placed, preferably by rolling it over, onto the
second carrier platform (25A) as shown in Figure 6-B.
20 d. the operator (34) presses the press element (26A) to release the second
carrier platform (25A) and slides it over the second support platform
(24A) towards the inactive roll shaft (17) as shown in Figure 6-C.
e. preferably simultaneously, the second base plate (22A) slides vertically till
the axis of the inactive roll shaft (17) becomes concentric with the axis of
25 the replacement roll (30) as shown in Figure 6-D.
f. the sliding second carrier platform (25A) is further moved such that the
replacement roll (30) inserts into the inactive roll shaft (17) and stops once
it reaches the distance piece (19) that acts as a barrier for further
advancement as shown in Figure 6-E.
14
g. the fabric (28A) is unwound by the operator and is overlaid onto the third
and fourth guide rods (12A and 13A) as shown in Figure 6-F, 6-G.
h. once the fabric (28) from the active roll (29) comes near its end as shown
in Figure 6-G, it is stopped by the operator from unwinding. The operator
5 lowers the press assembly (9) with the help of handle (9C) onto the fabric
(28) such that the fabric (28) is held down in position and cut transversely
across its width at a suitable point, and the remaining fabric (28) (which is
hanging loose from the point of cut) is wound back on the active roll (29)
as shown in Figure 6-H.
10 i. the slidable platform (11) is now moved by the drive motor (20) laterally
to move the active roll (29) away from the unwinding position (31) such
that it assumes an inactive position, and whereby said replacement roll
(30) is placed in the unwinding position (31).
j. the fabric (28A) from the replacement roll (30) is now passed over the first
15 guide roller (6) and is joined with already overlaid fabric (28) (which was
unwound from the active roll (29)) by any mechanical or
electromechanically means such as welding, gluing, pasting as shown in
Figure 6-I.
k. the press assembly (9) is now raised so that unwinding of the fabric (28A)
20 from the replacement roll (30) begins as shown in Figure 6-J.
The replacement roll (30) has now become the active roll (29), and the previously
active roll is now an empty fabric roll. The empty fabric roll is removed from its
shaft and away from the carrier platform (25) as shown in Figure 6-K & 6-L so
25 that a new replacement roll may be mounted on it, when the currently active roll
needs replacing.
It is evident from the foregoing discussion that the invention has a number of
embodiments.
30
15
In the preferred embodiment, an apparatus for changeover of an unwinding roll of
fabric of the invention comprises the following;
- a main frame (1) over which said fabric unwinds, and which is affixed to
ground by its base members (2),
5 - a slidable frame (11), which is equipped to support two rolls of said fabric,
namely an active roll (29) and a replacement roll (30), and which is
capable of sliding in a direction parallel to the axes of said rolls (29, 30),
- at least two support platforms (24, 24A) on which said carrier platform
(25, 25A) is slidable.
10
The key aspect of the preferred embodiment is that the slidable frame (11) is
capable of sliding in a first direction to place said active roll (29) in the unwinding
position while it supports said replacement roll (30) for pre-unwinding fabric
preparation, and wherein upon completion of required amount of unwinding of
15 fabric from said active roll (29), said sliding frame (11) is capable of sliding in a
second direction to place said replacement roll (30) in the unwinding position,
wherein said sliding in first and second directions takes place on corresponding
said support platform (24 or 24A), and wherein said support platforms (24, 24A)
are firmly affixed to the ground by any kind of mechanical means such as bolting
20 or grouting or clamping.
In another embodiment of the apparatus of the invention, the main frame (1)
comprises a right arm (3) and a left arm (4) which are connected by at least one
joining element (5) so as to make the main frame (1) sturdy, a first guide roller
25 (6), a second guide roller (7), and a third guide roller (8) that are mounted on the
right arm (3) and left arm (4) in a position to guide the fabric (28) unwinding from
the active roll (29).
In yet another embodiment of the apparatus of the invention, a press assembly (9)
30 is provided to apply pressure on the fabric (28) during the unwinding operation.
16
In still another embodiment of the apparatus of the invention, the slidable frame
(11) comprises a support wall (21) on the opposite faces of which are mounted an
inactive roll shaft (17) for mounting said replacement roll (30) and an active roll
shaft (18) for mounting said active roll (29); and at least two members – a front
5 rail guide (16) and a back rail guide (16A) – being slidably mounted over said
base members (2), on its one side a first guide rod (12) and a second guide rod
(13), and on its other side, a corresponding third guide rod (12A) and a fourth
guide rod (13 A), wherein said first and third guide rods (12, 12A) and the second
and fourth guide rods (13, 13A) are connected to each other to with connecting
10 rods (14).
In a further embodiment of the apparatus of the invention, the support wall (21) is
fixedly connected to the front and back rail guides (16, 16A) using any
mechanical means such as welding or bolting or screwing to form a rigid part.
15
In a yet further embodiment of the apparatus of the invention, the replacement
fabric (28A) is arranged around said respective guide rods (12A and 13A) to
expose said replacement fabric (28A) for preparation at the time of fabric
changeover.
20
In a still further embodiment of the apparatus of the invention the assembly of
guide rods (12, 13, 12A, 13A) interconnected by connecting rods (14) is affixed to
the slidable frame (11) by a bracket (15) using any mechanical arrangement such
as welding, bolting or screwing.
25
In another embodiment of the apparatus of the invention, the vertical level of the
active roll shaft (18) during its working position is adjusted using a first vertical
level adjustment mechanisms (33) comprising a first base plate (22) on which the
active roll shaft (18) is mounted, and a pair of first vertical guide rails (23) that are
17
affixed to the support wall (21) and over which the first base plate (22) slides
vertically.
In yet another embodiment of the apparatus of the invention, the vertical level of
5 the inactive roll shaft (17) during its working position is adjusted using a second
vertical level adjustment mechanisms (33A) comprising a second base plate (22A)
on which the inactive roll shaft (17) is mounted, and a pair of second vertical
guide rails (23A) that are affixed to the support wall (21) and over which the
second base plate (22A) slides vertically.
10
In one more embodiment of the apparatus of the invention, the vertical sliding
movement of the first base plate (22) is controlled by a first guide rail motor (10),
and the vertical sliding movement of the second base plate (22A) is controlled by
a second guide rail motor (10A)wherein said motors (10, 10A) are provided with
15 braking arrangement so as to hold the roll shafts (17, 18) at their desired levels in
a stationary condition.
In still another embodiment of the apparatus of the invention, a set of sensors is
provided to determine the position of the movement of the roll shafts (17, 18) in
20 upwards and downwards direction.
In still another embodiment of the apparatus of the invention, a distance piece
(19) is provided on each of the roll shafts (17, 18) as a barrier or a stopper for the
rolls (29, 30) for aligning the respective rolls (29, 30) centrally on their respective
25 roll shafts (18, 17).
In a further embodiment of the apparatus of the invention, the support wall (21) is
made from multiple structural members or from a single block.
18
In a yet further embodiment of the apparatus of the invention, the front and back
rail guides (16, 16A) are linear members with a tubular or round cross section, or
any kind of structural member capable of smoothly sliding over said base
members (2), and wherein the length of the front and back guide rails (16, 16A)
5 may be different from each other.
In a still further embodiment of the apparatus of the invention, any one of said
guide rails (16, 16A) comprises a drive unit (32) to drive the slidable frame (11)
by a drive motor (20) to and fro.
10
In another embodiment of the apparatus of the invention, a first carrier platform
(25) provided which is slidable over said first support platform (24) on a pair of
first rails (27) affixed to said first support platform (24), and a second carrier
platform (25A) provided which is slidable over said second support platform
15 (24A) on a pair of second rails (27A) affixed to said second support platform
(24A).
In yet another embodiment of the apparatus of the invention, the carrier platforms
(25 and 25A) are locked in position on respective support platforms (24 and 24A)
20 with a locking assembly (26) is provided on each of said support platforms (24
and 24A).
In yet another embodiment of the apparatus of the invention, the locking assembly
(26) comprises a press element (26A), spring element (26B) and a hinge (26C)
25 wherein said press element (26A), when pressed, lowers a projection (2D)
attached to said press element (26A) and when said press element is released, said
projection comes back up with the help of said spring element (2B), and engages
into a cavity (26E) provided in the first and second carrier platforms (25, 25A).
19
In still another embodiment of the apparatus of the invention, the said press
assembly (9) comprises at least one pair of press arms (9A) which are connected
together by an overlaying arm (9B), a handle (9C) provided to move the press
assembly manually towards and away from the unwinding fabric (28) about a
5 pivot (9D), said movement being achieved by a hinge mechanism or by bush and
pin arrangement to swing the press assembly (9) about an axis.
In one more embodiment of the apparatus of the invention, the said press arm
(9A) and said overlaying arm (9B) are made of metallic or non-metallic materials
10 and of which one end comprises of a handle (9C) and another end pivot (9D).
The preferred embodiment of the method of changeover of an unwinding roll of
fabric on the apparatus as described in the aforementioned embodiments
comprises the following steps:
15 a. inspecting and preparing the starting portion of the replacement fabric
(28A) of a replacement roll (30);
b. sliding said second carrier platform (25A) over the second support
platform (24A) and locking it in position and rolling the said inspected
and prepared replacement roll (30) onto said second carrier platform
20 (25A);
c. pressing the press element (26A) to release the second carrier platform
(25A) carrying said replacement roll (30) and sliding it over said second
support platform (25) towards the inactive roll shaft (17) as shown in
Figure 6-C.
25 d. using second vertical level adjustment mechanism (33A), sliding the
second base plate (22A) vertically to align the axis of the inactive roll
shaft (17) affixed to said second base plate (22) concentrically with the
axis of the replacement roll (30);
20
e. sliding second carrier platform (25A) further to mount said replacement
roll (30) over said inactive roll shaft (17) and keep sliding it till it
reaches the distance piece (19);
f. unwinding replacement fabric (28A) and arranging it around the third
5 and fourth guide rods (12A and 13A);
g. stopping unwinding of fabric (28) from the active roll (29) and holding
it down in position using the press assembly (9) and making a transverse
cut in it;
h. moving said slidable platform (11) to carry said active roll (29) away
10 from the unwinding position (31) to an inoperative position, and
whereby said replacement roll (30) is placed in the unwinding position
(31);
i. passing fabric (28A) from the replacement roll (30) over the first guide
roller (6) to join with already overlaid fabric (28), thereby completing
15 the changeover from active fabric (28) to replacement fabric (28A).
In an embodiment of the method, the vertical sliding movement of said second
base plate (22A) of said step d is controlled by a second guide rail motor (10A),
and wherein said motors (10A) is provided with braking arrangement so as to hold
20 the inactive roll shaft (17) at their desired levels in a stationary condition.
In another embodiment of the method of the invention, the position of the inactive
roll shaft (17) movement in upwards and downwards direction in step d is
determined by sensors.
25
In yet another embodiment of the method of the invention, the lateral movement
of slidable frame (11) is carried out by a by a drive motor (20) controlled by a
drive unit (32).

We Claim:

1. An apparatus for changeover of an unwinding roll of fabric characterised
in that said apparatus comprises:
- a main frame (1) over which said fabric unwinds, and which is affixed
5 to ground by its base members (2), over which an active roll (29) of
fabric unwinds,
- a slidable frame (11), which is equipped with a support wall (21) to
support two rolls of said fabric, namely said active roll (29) and a
replacement roll (30), and which is capable of sliding in a direction
10 parallel to the axes of said rolls (29, 30),
- at least two support platforms (24, 24A) on which said main frame (1)
is slidable
wherein said slidable frame (11) is capable of sliding in a first direction to
place said active roll (29) in the unwinding position while it supports said
15 replacement roll (30) for pre-unwinding fabric preparation, and wherein
upon completion of required amount of unwinding of fabric from said active
roll (29), said sliding frame (11) is capable of sliding in a second direction
to place said replacement roll (30) in the unwinding position, wherein said
sliding in first and second directions takes place on corresponding said
20 support platform (24 or 24A) which are firmly affixed to the ground by any
kind of mechanical means such as bolting or grouting or clamping.
2. The apparatus as claimed in claim 1, wherein said main frame (1) comprises
a right arm (3) and a left arm (4) which are connected by at least one joining
25 element (5) so as to make the main frame (1) sturdy, a first guide roller (6),
a second guide roller (7), and a third guide roller (8) that are mounted on the
right arm (3) and left arm (4) in a position to guide the fabric (28)
unwinding from the active roll (29).
22
3. The apparatus as claimed in claims 1 and 2, wherein a press assembly (9) is
provided on said main frame (1) to apply pressure on the fabric (28) during
the fabric changeover operation.
5 4. The apparatus as claimed in claims 1 to 3, wherein said slidable frame (11)
has an inactive roll shaft (17) for mounting said replacement roll (30) and an
active roll shaft (18) for mounting said active roll (29), both said shafts (17,
18) mounted on opposite faces of said support wall (21); and at least two
members – a front rail guide (16) and a back rail guide (16A) – being
10 slidably mounted over said base members (2), on its one side a first guide
rod (12) and a second guide rod (13), and on its other side, a corresponding
third guide rod (12A) and a fourth guide rod (13 A), wherein said first and
third guide rods (12, 12A) and the second and fourth guide rods (13, 13A)
are connected to each other to with connecting rods (14).
15 5. The apparatus as claimed in claims 1 to 4, wherein said support wall (21) is
fixedly connected to the front and back rail guides (16, 16A) using any
mechanical means such as welding or bolting or screwing to form a rigid
part.
20 6. The apparatus as claimed in claims 4 and 5, wherein said replacement fabric
(28A) is arranged around said third and fourth guide rods (12A and 13A) to
expose said replacement fabric (28A) for preparation at the time of fabric
changeover.
25 7. The apparatus as claimed in claims 4 to 6, wherein the assembly of guide
rods (12, 13, 12A, 13A) interconnected by connecting rods (14) is affixed to
the slidable frame (11) by a bracket (15) using any mechanical arrangement
such as welding, bolting or screwing.
23
8. The Apparatus as claimed in claims 4 to 7, wherein the vertical level of the
active roll shaft (18) during its working position is adjusted using a first
vertical level adjustment mechanism (33) comprising a first base plate (22)
on which the active roll shaft (18) is mounted, and a pair of first vertical
5 guide rails (23) that are affixed to the support wall (21) and over which the
first base plate (22) slides vertically.
9. The Apparatus as claimed in claims 4 to 8, wherein the vertical level of the
inactive roll shaft (17) during its working position is adjusted using a second
10 vertical level adjustment mechanism (33A) comprising a second base plate
(22A) on which the inactive roll shaft (17) is mounted, and a pair of second
vertical guide rails (23A) that are affixed to the support wall (21) and over
which the second base plate (22A) slides vertically.
15 10. The apparatus as claimed in claims 4 to 9, wherein the vertical sliding
movement of the first base plate (22) is controlled by a first guide rail motor
(10), and the vertical sliding movement of the second base plate (22A) is
controlled by a second guide rail motor (10A), and wherein said motors (10,
10A) are provided with braking arrangement so as to hold the roll shafts
20 (17, 18) at their desired levels in a stationary condition.
11. The apparatus as claimed in claims 1 to 10, wherein a set of sensors is
provided to determine the position of the movement of the roll shafts (17,
18) in upwards and downwards direction.
25
12. The apparatus as claimed in claims 1 to 11, wherein a distance piece (19) is
provided on each of the roll shafts (17, 18) as a barrier or a stopper for the
rolls (29, 30) for aligning the respective rolls (29, 30) centrally on their
respective roll shafts (18, 17).
30
24
13. The apparatus as claimed in claims 1 to 12, wherein said support wall (21) is
made from multiple structural members or from a single block.
14. The apparatus as claimed in claims 4 to 13, wherein said front and back rail
5 guides (16, 16A) are linear members with a tubular or round cross section,
or any kind of structural member capable of smoothly sliding over said base
members (2), and wherein the length of the front and back guide rails (16,
16A) may be different from each other.
10 15. The apparatus as claimed in claims 4 to 14, wherein any one of said guide
rails (16, 16A) comprises a drive unit (32) to drive the slidable frame (11)
by a drive motor (20) to and fro.
16. The apparatus as claimed in claims 4 to 15 wherein a first carrier platform
15 (25) provided which is slidable over said first support platform (24) on a
pair of first rails (27) affixed to said first support platform (24), and a
second carrier platform (25A) provided which is slidable over said second
support platform (24A) on a pair of second rails (27A) affixed to said
second support platform (24A).
20
17. The apparatus as claimed in claim 1, wherein said carrier platforms (25 and
25A) are locked in position on respective support platforms (24 and 24A)
with a locking assembly (26) provided on each of said support platforms (24
and 24A).
25
18. The apparatus as claimed in claim 17, wherein said locking assembly (26)
comprises a press element (26A), spring element (26B) and a hinge (26C)
wherein said press element (26A), when pressed, lowers a projection (26D)
attached to said press element (26A) and when said press element is
30 released, said projection comes back up with the help of said spring element
25
(26B), and engages into a cavity (26E) provided in the first and second
carrier platforms (25, 25A).
19. The apparatus as claimed in claims 3 to 18, wherein said press assembly (9)
5 comprises at least one pair of press arms (9A) connected together by an
overlaying arm (9B), a handle (9C) provided to move the press assembly
manually towards and away from the unwinding fabric (28) about a pivot
(9D), said movement being achieved by a hinge mechanism or by bush and
pin arrangement to swing the press assembly (9) about an axis.
10
20. The apparatus as claimed in claim 19 said press arm (9A) and said
overlaying arm (9B) are made of metallic or non-metallic materials and of
which one end comprises of a handle (9C) and another end pivot (9D).
15 21. A method of changeover of an unwinding roll of fabric on the apparatus as
claimed in claims 1 to 20, characterised in that said method comprises the
steps of:
a. inspecting and preparing the starting portion of the replacement fabric
(28A) of the replacement roll (30);
20 b. sliding said second carrier platform (25A) over the second support
platform (24A) and locking it in position and rolling the said inspected
and prepared replacement roll (30) onto said second carrier platform
(25A);
c. pressing the press element (26A) to release the second carrier platform
25 (25A) carrying said replacement roll (30) and sliding it over said second
support platform (24A) towards the inactive roll shaft (17) as shown in
Figure 6-C.
d. using second vertical level adjustment mechanism (33A), sliding the
second base plate (22A) vertically to align the axis of the inactive roll
26
shaft (17) affixed to said second base plate (22) concentrically with the
axis of the replacement roll (30);
e. sliding second carrier platform (25A) further to mount said replacement
roll (30) over said inactive roll shaft (17) and keep sliding it till it
5 reaches the distance piece (19);
f. unwinding replacement fabric (28A) and arranging it around the third
and fourth guide rods (12A and 13A);
g. stopping unwinding of unwinding fabric (28) from the active roll (29)
and holding it down in position using the press assembly (9) and
10 making a transverse cut in it;
h. moving said slidable platform (11) to carry said active roll (29) away
from the unwinding position (31) to an inoperative position, and
whereby said replacement roll (30) is placed in the unwinding position
(31);
15 i. passing said fabric (28A) from the replacement roll (30) over the first
guide roller (6) and is joined with already overlaid fabric (28), thereby
completing the changeover from active fabric (28) to replacement fabric
(28A).
20 22. The method as claimed in claim 21, wherein said vertical sliding movement
of said second base plate (22A) of said step d is controlled by a second
guide rail motor (10A), and wherein said motors (10A) is provided with
braking arrangement so as to hold the inactive roll shaft (17) at their desired
levels in a stationary condition.
25
23. The method as claimed in claims 21 and 22, wherein the position of the
inactive roll shaft (17) movement in upwards and downwards direction in
step d is determined by sensors.
27
24. The method as claimed in claims 21 to 23, wherein the lateral movement of
slidable frame (11) is carried out by a by a drive motor (20) controlled by a
drive unit (32).
5 25. The method as claimed in claim 21, wherein all steps a to i are carried out
by an operator (34).