This invention relates to apparatus for cutting a web of sheet material, and
particularly a moving web in a processing line.
5 Background Of Invention
There are many processing lines and conversion lines wherein the web cutting
systems are already in usage. The conventional knife arrangements of prior art
patent have proved to be highly successful in the handling of sheet materials of
the types listed therein, namely cardboard, plastics and like materials which are
10 relatively thick or otherwise resistant to conventional cutting knives. However,
these systems have not been satisfactory for use with webs of materials which
have a high tendency to elongate under stress and/or a low coefficient of friction
such for example as woven and nonwoven plastic fibre or filament webs.

15 The problem which arises in the cutting of such webs derives from the basic fact
that with any knife which relies for the cutting action on its passage through an
inadequately supported web, as distinguished from a guillotine type knife which
cuts directly against an anvil, the tension in the web is an essential factor in the
cutting action. In other words, the tension in that portion of the web which
20 opposes the knife must be adequate to keep the web sufficiently taut for passage
of the knife therethrough, rather than merely stretching the web without the knife
penetrating it. This problem is especially acute in connection with webs which
have such a high tendency to elongation under stress that they must be handled in
a processing line and rewound under very low tension to prevent permanent
25 elongation in the wound roll. A typical example of such a web is a woven plastic
of such high tendency to stretching. If it is attempted to cut such a web with the
knife arrangement of, for example, U.S. Pat. No.3,794,255, the required
elongation will occur between the knife and the winding roll causing excessive
knife travel. In addition, some web materials, depending upon their coefficient of
3
friction, will skid against the driving drum before enough tension can be
developed to cut the web
Thus, there is a need for a more efficient cutting system for continuously moving
5 web, particularly woven plastic fabric moving at higher speed and which
overcomes the aforementioned drawbacks of the conventional systems.
Objects of Invention:
The main objective of the present invention is to provide a cutting apparatus or
10 device or system to facilitate accurate cutting of a continuously moving web
made of woven plastic.

A further objective of the present invention is to provide a cutting device or
system which allows rapid cutting of a continuously moving web made of woven
15 plastic with low maintenance cost.

Another objective of the present invention is to provide a cutting device or system
which provides flexibility in handling of different specification webs without
much alteration in the device or system???.
20
Summary Of Invention:
The web or fabric cutting apparatus of the present invention comprises a transport
table for the workpiece movement and a movable knife, the knife being preferably
guided along an orbit. The web cutting apparatus disclosed herein enables highest
25 throughput rates of workpieces and whereby the web cutting apparatus is
advantageously used for the separation of workpieces from a woven plastic web.
When the knife is in an orbit, it can be guided at a uniform speed, reducing power
consumption for the gear motor or the drive, increasing life and reducing
maintenance.
30
4
The knife, in the form of a blade, is mounted on a conveyance means, such as a
belt. The conveyance means rotates in a direction that is nearly transverse to the
direction of movement of the unrolling web or fabric.

5 The roll carrying a fabric that needs cutting into pieces is unwound from an
unwinding unit. The fabric may be made of stretched plastic tape, which is
optionally coated, or of plastic film, or of composite materials of fabric and plastic
films.

10 The unwound fabric travels on a transportation means or a conveyance means
onto a cutting platform. The conveyance means may be operated using driven
rollers, for example. Adjacent to the worktable is provided a transverse transport
device which is in the form of a conveyor belt (not shown), and clamping means
for workpieces, such as grippers or magnets.
15
The separation of a leading workpiece from the continuously arriving unrolled
fabric takes place by means of the apparatus disclosed herein which essentially is
a cutting device which comprises at least one movable knife, wherein the knife is
guided along an orbit, which in the circumferential direction, substantially
20 transversely to the longitudinal transport direction aligned endless belt to which at
least one blade is fixed. The endless belt runs around two rollers, at least one of
the two rollers is driven by a motor with speed controller, preferable a servomotor. The knife severed the incoming workpiece across the width by travelling at
controlled speed based on incoming workpiece traverse rate.
25
The cut made using the device disclosed herein is of high quality, i.e. a smooth
and precise cut is produced.

5
The transverse transport device conveys individual workpieces, away from the
work area in a transverse transport direction which is oriented orthogonally to the
longitudinal transport direction.
5 In a subsequent process step, once the knife has already completely cut off the
single workpiece from the contiguous workpieces, it moves along its orbit to the
top of the endless belt and thus out of contact with the workpieces. The individual
workpiece is conveyed away from the working area by means of the transverse
transport device in the transverse transport direction.
10 Brief Description Of Figures in the drawings:
Figure 1 shows the perspective view of general arrangement of the web cutting
apparatus of the invention.
Figure 1A shows the moving web gripped by pre draw roller assembly, post draw
15 roller assembly, first tension roller assembly and second tension roller assembly.
Figure 2 shows the section view of cross cutting device which moves the blade in
the orbit that is in the traverse direction to that of the moving web.
Figure 2A shows cross sectional view of the cross cutter apparatus.
Figure 3 shows perspective view of the cross cutter apparatus with protective
20 covers and maintenance facility.
Figure 4 shows perspective view of the movable knife assembly.
Figure 4A shows perspective view of the connection of movable knife assembly
with the cross cutter apparatus.
Figure 5 shows the top view of the cross-cutter apparatus.
25 Figure 5A shows the schematic view of cross cutting operation.
List of Parts:
1. Web cutting apparatus
2. Web
30 3. Base frame
4. First Side plate
6
5. Second Side plate
6. First Web guide roller
6A.Second Web guide roller
6B.Third Web guide roller
5 7. Cross cutter apparatus
8. Cutting platform
9. Pre-draw roller assembly
10. First motor
11. Post-draw roller assembly
10 12. Second motor
13. First Tension Roller
assembly
14. Second Tension Roller
assembly
15 15. Web cut piece
16. First Pneumatic cylinder
17. Second Pneumatic cylinder
18. Third Pneumatic cylinder
19. Fourth Pneumatic cylinder
20 20. First Lever
21. Second Lever
22. Third Lever
23. Fourth Lever
24. First Holding block
25 25. Second Holding block
26. Front plate
27. Rear plate
28. First pulley
29. Second pulley
30 30. Third pulley
31. Housing
32. First Shaft
33. Adjusting plate
34. Second Shaft
35 35. Fourth pulley
36. First Endless belt
37. Second Endless belt
38. Movable knife assembly
39. First Guide rail
40 40. Second Guide rail
41. Third Guide rail
42. Fourth Guide rail
43. Bottom cylindrical spacer
44. Top flat spacer
45 45. Front protection cover
46. Swivel cover
47. Third motor
48. Knife
49. Knife holding bracket
50 50. Knife holding plate
51. First Guide pin
52. Second Guide pin
53. First Side sheet
54. Second Side sheet
55 55. Belt attachment
56. Knife movement axis
57. Web movement axis
58. Pulley cover
59. Position A
60 60. Position B
7
61. Position C
62. Position D
63. First Opening
64. Second opening
5 65. First rod
66. Second rod
67. Clamp
68. first longitudinal edge of
fabric
10 69. Second longitudinal edge of
fabric
Detail Description Of Invention with reference to drawings:
Figure 1 shows the apparatus of the present invention which is a web or fabric
15 cutting apparatus (1) which facilitates accurate cutting of a continuously moving
web (2) made of woven fabric such as plastic. The apparatus (1) comprises of a
first side plate (4) and a second side plate (5) which are connected to and
supported by a base frame structure (3) and cross cutting apparatus (7) with
moving knife assembly (38). The base frame structure (3) is constructed of a
20 plurality of the rectangular cross-sectional members which are jointed or welded
together to form a sturdy base.
In one of the embodiments, the side plates (4, 5) are constructed in the form of a
thick plates and are attached to the base frame structure (3) by any kind of joining
25 means such as welding, bolting or screwing to form a rigid member.
The apparatus (1) further comprises a cutting platform (8) onto which the
continuous moving web (2) from the unwinder (not shown) is conveyed in the
direction shown by dotted arrow in Figure 1 by a pull-off driven roller (not
30 shown) and passes through a set of web guiding rollers (6, 6A, and 6B) to
maintain proper tension and avoiding shrinkage of the web (2).
The apparatus (1) also comprises of a pre-draw roller assembly (9) and post-draw
roller assembly (11). Using a cross cutter apparatus (7), the cutting of the moving
35 web (2) takes place in between of the rollers (9, 11) on the cutting platform (8),
8
whereby the continuous web (2) is converted into the web cut pieces (15). The pre
draw roller assembly (9) and post draw roller assembly (11) are individually
constructed in such a way that they both have a plurality of rollers mounted on a
single shaft.
5
As shown in figure 1A, the apparatus (1) further comprises of first tension rollers
assembly (13) and second tension roller assembly (14) which are used for the
holding of the web (2) and also presses the web (2) from above onto the pre-draw
roller assembly (9) and post-draw roller assembly (11) all over the traverse web
10 length with the help of pneumatic cylinders such that web (2) lies between the
roller assemblies (9, 11, 13, and 14) . The first pneumatic cylinder (16) and
second pneumatic cylinder (17) works together in the downwards direction and
pushes the first tension roller assembly (13) at both ends. The first and second
pneumatic cylinders (16, 17) are connected to the tension roller assembly (13) via
15 a first lever (20) and second lever (21) respectively. The said connection can be
obtained by any mechanical method of bolting, screwing or using bush or bearing
arrangement such that the downwards movement of the cylinders (16,17)
facilitates the movement of the first tension roller assembly (13) to press the web
(2) against the pre draw roller (9).
20
Further, the first tension roller assembly (13) and second tension roller assembly
(14) are responsible for maintaining adequate tension in and holding of the web
(2) during cutting so that clean and accurate cutting takes place. This web tension
is created by the difference in speed between the pre-draw roller assembly (9) and
25 post -draw roller assembly (11). The post-draw roller assembly (11) speed
measured in rpm is slightly higher than the speed of pre-draw roller assembly (9),
the rpm of pre draw roller assembly (9) is controlled by the first motor (10) and
the rpm of post draw roller assembly (11) is controlled by second motor (12).
Such difference in the rpm is also required to pull the web (2) in the direction of
30 web movement axis (57).
9
In the same way, a third pneumatic cylinder (18) and fourth pneumatic cylinder
(19) work together in the downward direction and push the second tension roller
assembly (14) at both ends. The third and fourth pneumatic cylinders (18, 19) are
5 connected to the second tension roller assembly (14) at the ends via a third lever
(20) and fourth lever (23) respectively. The said connection can be obtained by
any mechanical method of bolting, screwing or using bush or bearing arrangement
such that the downward movement of the cylinders (18,19) facilitates the
movement of the second tension roller assembly (14) to press the web (2) against
10 the post draw roller (11).
It is evident from the Figure 1A that, pre draw roller assembly (9) and post draw
roller assembly (11) are identical in construction with plurality of rollers. These
rollers can be chosen from the set of rolling members such that while drawing the
15 web (2) in the direction of web movement axis (57) the rollers provide negligible
friction to the surface of web (2) due to which the web (2) does not get damaged.
The first tension roller assembly (13) and second tension roller assembly (14) also
comprises of plurality of rollers mounted on a first and second rod (65, 66)
respectively thereby connecting the rod (65, 66) individually with the at least two
20 brackets (67).
Figure 2 shows the internal construction of the cross cutter apparatus (7),
comprising of a moving cutting assembly (38) mounted on endless belt (36), two
parallel plates, a front plate (26) and a rear plate (27) which are mounted at a
25 prescribed gap as shown in figure 2A that is maintained by a set of top flat spacer
(44) and a set of bottom cylindrical spacers (43). The front and rear plates (26, 27)
can be constructed from a metallic or non-metallic plate which can bear the load
of the other supporting members. Cross cutter apparatus (7) is located on the
cutting platform (8) at an inclined angle α as shown in figure 5 perpendicular in
30 direction with respect to the web movement direction (56) and cross cutter
10
apparatus (7) mounted on the first side plate (4) and second side plate (5) via first
holding block (24) and second holding block (25). The said mounting can be
achieved by any mechanical means such as bolting, screwing or welding.
5 The cross cutter apparatus further comprises of a rear plate (27) wherein at the
ends of the said rear plate (27), a first pulley (28) and at the other end a second
pulley (29) are mounted. The said first pulley (28) is connected to third pulley
(30) via first stationary housing (31) and a first rotating shaft (32) and on the
other end second pulley (29) mounted on the rear plate (27) is connected with the
10 adjustment bracket (33) as shown in figure 5 and second rotating shaft (34).
By moving the adjustment bracket (33) as shown in figure 5, the second pulley
(29) can be moved farther from the first pulley (28). Such movement is required
to increase or decrease the tension in the first endless belt (36) which passes over
15 the pulleys (28,29).
Further, the third pulley (30) is driven by fourth pulley (35) shown in figure 3
through endless second belt (37). Hence, the rotation is transmitting from third
motor (47) as shown in Figure 3 which is mounted on first side plate (4) to fourth
20 pulley (35) and from fourth pulley (35) to third pulley (30) which are connected
through endless second belt (37) and then from third pulley (30) which are
directly coupled to first pulley (28) and finally from first pulley (28) to second
pulley (29) which are connected through endless first belt (36).
25 In one of the embodiments, the pulleys can be selected from the set of round
grooved members having toothed or non-toothed profile, such that profile can be
of any shape or size which can drive the belts along with it. Also, these pulleys are
efficient enough to transmit the motor power and drive the belts smoothly.
11
In another embodiment, the belts can be selected from set of flexible members
having toothed profile same as of pulleys and can withstand the wear and tear.
The belts can be of any type such as flat belts, V belts, round belts, spring belts,
multi groove belts, timing belts, speciality belts or of any kind known to person
5 skilled in art.
Movable knife assembly (38) mounted on the first endless belt (36) which makes
movable knife assembly (38) rotates in the orbit that is circumferential on the path
of the first endless belt (36) which runs over the first pulley (28) and second
10 pulley (29) to cut the web fabric in to workpiece smoothly.
As can be seen from Figure 4A, the said movable knife assembly (38) is further
supported and guided by the guide rails in between first pulley (28) and second
pulley (29) on top and bottom positions. The said guide rails are mounted on the
15 front plate (26) and rear plate (27) in such a manner that opposite guide rails face
each other. The first Guide rail (39) and the second guide rail (40) are mounted on
the front plate (26) at top and bottom position where as the third guide rail (41)
and fourth guide rail (42) are mounted on the rear plate (27) exactly opposite to
the first guide rail (39) and second guide rail (40) as shown in Figure 2A.
20
In one of the embodiments, these guide rails (39, 40, 41, and 42) may be made of
any shape such as u shape cross section or any other cross section such as v
shape, curve shape such that the movable knife assembly moves freely through it.
25 Figure 3 shows perspective view of the cross cutter apparatus (7) comprises of
front protective cover (45) and a swivel cover (46). Front protection cover (45)
covers the knife (48) moving path to avoid any accident and pulley cover (58) is
also provided to cover the rotating part to avoid any accident. At the top of the
cross cutter apparatus (7) one swivel cover (46) is provided for the changing of
30 the knife (48) when the knife (48) is worn-out so that there is no need to open the
12
whole cross cutter apparatus (7) for changing the worn out knife which has to be
done periodically. Further, the cross cutter apparatus (7) is driven by the third
motor (47) which is coupled with the fourth pulley (35) and is connected to the
third pulley (30) via endless belt (37).
5
In one of the embodiments, the front protective cover (45) may be constructed of
a sheet metal or plate bend to form a rigid body which can withstand the external
impact if occur during the cutting process.
10 In another embodiment, the swivel cover (46) can also be constructed of a sheet
metal or plate bend to form a rigid surface. Also, the swivel cover (46) can be
opened and closed whenever the blade (48) of the movable knife assembly (38)
requires to be changed when it is worn out. Such change can take place by driving
the movable knife assembly (38) to position D (62) and thereby opening the
15 swivel cover (46). The position D (62) can be determined by set of sensors (not
shown) which governed the stoppage of the movable knife assembly (38).
Figure 4 shows the movable knife assembly (38) which comprises of knife
holding bracket (49) on which the knife (48) is located and mounted through the
20 knife holding plate (50) such that knife (48) lies between the holding bracket (49)
and holding plate (50). The knife (48) can be selected from set of any sharp object
which is capable of cutting the web (2) perfectly and smoothly without any
hindrance.
25 The movable knife assembly (38) further comprises of first guide pin (51) and a
second guide pin (52) that are clamped between the first side sheet (53) and
second side sheet (54) in such a way that it forms a rigid body. First side sheet
(53) and second side sheet (54) are mounted on the knife holding bracket (49) that
creates the prescribed gap (not shown) between both the sheets so that the swivel
30 action of guide pins can take place smoothly. First side sheet (53) and second side
13
sheet (54) are constructed in arc-shaped form so that they are able to run on the
circular periphery of the first pulley (28) and second pulley (29).
Further, the said movable knife assembly (38) also comprises of first opening (63)
5 and second opening (64) for positioning of first endless belt (36) through which,
the movement of the movable knife assembly (38) is driven .
Figure 4A, shows perspective view of movable knife assembly (38) wherein guide
pin (52) moves along the profile of the fourth guide rail (42) and second guide rail
10 (40). As mentioned earlier, the movable knife assembly (38) is connected to the
first endless belt (36) such that the said movable knife assembly (38) is driven by
the first endless belt (36) along the path as defined by the first endless belt (36).
Figures 5 and 5A show the top view of cross cutter apparatus (7) and schematic
15 view of the cutting operation. As shown in the Figures 5 and 5A cross cutter
apparatus (7) is mounted at an inclined angle α perpendicular in direction with
respect to the web (2) movement direction axis (57).
Cutting speed of cross cutter is set in such a way so that time required by the
20 knife (48) to travel from position A (59) to position B (60) is same as the time
required taken by the fabric to move from position C (61) to position B (60).
Inclined mounting of cross cutter apparatus (7) provides the flexibility to the
system to set the driving speed of the cutter knife (48) with respect to the
25 continuous moving web (2).
The present invention also provides a method of cutting a moving web (2).. The
said method uses the apparatus (1) for cutting a moving web (2) disclosed on the
foregoing pages. The method of the cross-cutting of the moving web (2)
30 according to the present invention comprises of following steps:
14
 Web (2) is pulled by the pull-off roller from the unwinder roll.
 Web (2) passes through the web guide rollers (6,6A,6B) to maintain
proper tension and removing shrinkage of the web (2).
 Web (2) is further pulled through the post-draw roller assembly (11) and
5 pre-draw roller assembly (9) where tension rollers assembly (13,14)
provides proper holding during cutting of the web (2).
 Web (2) exit from the pre-draw roller assembly (9) and when it comes
under the cross cutter apparatus (7) mounted at an inclined angle with
respect to the web movement axis (57), movable knife assembly (38)
10 which is mounted on the first endless belt (36) between the two pulleys
(28,29) cuts the web (2) simultaneously the post-draw roller assembly
(11) and pre draw roller assembly (9) holds the web (2) during cutting to
provide proper tension and holding.
Movable knife assembly (38) moves and guided by the first endless belt
15 (36) and the guiding rails (39, 40, 41, and 42) so that it can move in the
required orbit.
 Required web cut piece is transferred for further processing as desired.

The method disclosed herein has further embodiments described as follows.
20 In one of the embodiments, the rotational speed of said post-draw roller assembly
(11) is slightly higher than the rotational speed of the pre-draw roller assembly
(11) and wherein the rotational speed of said pre draw roller (9) is controlled by a
first motor (10) and the rotational speed of said post draw roller (11) is controlled
by a second motor (12).
25
In another embodiment, the cutting speed of said cross cutter (7) is set in such a
way that time required by said knife (48) to travel from a position A (59) on first
longitudinal edge (68) of fabric (2) to a position B (60) on the second
longitudinal edge (69) of said fabric (2) is same as the time required by the fabric
15
(2) to travel the distance between the position on said second longitudinal edge (9)
that corresponds to said position A to position B (60).
While the above description contains much specificity, these should not be
5 construed as limitation in the scope of the invention, but rather as an
exemplification of the preferred embodiments thereof. It must be realized that
modifications and variations are possible based on the disclosure given above
without departing from the spirit and scope of the invention. Accordingly, the
scope of the invention should be determined not by the embodiments illustrated,
10 but by the invention as a whole and in addition to appended claims and their legal
equivalents.

We Claim:

1. An apparatus for cutting a web (2) of woven sheet material, characterised
in that said apparatus comprises:
5 - a first side plate (4) and a second side plate (5) connected to and
supported by a base frame structure (3);
- a cutting platform (8) onto which the continuous moving web (2)
from an unwinder (not shown) is conveyed and passes through a set
of web guiding rollers (6, 6A, and 6B) so as to maintain proper
10 tension and ,thereby avoiding shrinkage of the web (2);
- a pre-draw roller assembly (9) and post-draw roller assembly (11),
both individually constructed to have a plurality of rollers mounted
on a single shaft;
- a cross cutter apparatus (7) having moveable knife assembly (38),
15 mounted at an inclined angle between said roller assemblies (9, 11),
- a first tension rollers assembly (13) and second tension roller
assembly (14) respectively mounted corresponding to said pre-draw
assembly (9) and post-draw assembly (11);
- a pair of pneumatic cylinders, namely a first pneumatic cylinder (16)
20 and a second pneumatic cylinder (17) connected to said first tension
roller assembly (13) using a first lever (20), and a second lever (21),
respectively, and another pair of pneumatic cylinders, namely third
pneumatic cylinder (18) and a fourth pneumatic cylinder (19)
corresponding to said second tension roller assembly (14), connected
25 to said second tension roller assembly (14) using a third lever (22),
and a fourth lever (23), respectively,
wherein said cross cutter apparatus (7) is capable of cutting said web (2)
using said movable knife assembly (38) in between of the rollers (9, 11)
17
on the cutting platform (8), whereby the continuous web (2) is cut into
the web cut pieces (15).
2. The apparatus as claimed in claim 1, wherein said connections to said first
5 lever (20) and second lever (21) with said first tension roller assembly
(13), and those of said third lever (23) and said fourth lever (24) with said
second tension roller assembly (14) can be of a type selected from bolted,
screwed, and bush or bearing arrangement whereby the downwards
movement of the corresponding cylinders (16, 17, and 18, 19) facilitates
10 the movement of the first tension roller assembly (13) to press the web (2)
against the pre draw roller (9), and that of said second tension roller
assembly (14) to press said web (2) against said post-draw roller (11).
3. The apparatus as claimed in claims 1 and 2, wherein the rotational speed
15 of said post-draw roller assembly (11) is slightly higher than the rotational
speed of the pre-draw roller assembly (9), wherein the rotational speed of
said pre draw roller assembly (9) is controlled by a first motor (10) and
the rotational speed of said post draw roller assembly (11) is controlled by
a second motor (12).
20
4. The apparatus as claimed in claims 1 to 3, wherein pre draw roller
assembly (9) and post draw roller assembly (11) are identical in
construction and have a plurality of rollers, and wherein said first tension
roller assembly (13) and second tension roller assembly (14) are of
25 identical construction each made of a plurality of rollers mounted on a set
of first and second rod (65, 66) respectively, said first rods (65) connected
to each other using a set of brackets (67).
5. The apparatus as claimed in claims 1 to 4, wherein said cross cutter device
(7) comprises:
18
- two parallel plates, a front plate (26) and a rear plate (27) mounted
at a predetermined gap maintained a set of top flat spacers (44) and
a set of bottom cylindrical spacers (43),
- a first pulley (28) mounted at one end of said rear plate (27) is
5 connected to a third pulley (30) via first stationary housing (31)
and a first rotating shaft (32), and a second pulley (29) mounted at
the other end of said rear plate (27) is connected with an adjustment
bracket (33) and a second rotating shaft (34);
- a first endless belt (36) which passes over said pulleys (28, 29).
10 - a moveable knife assembly (38) connected to said endless belt (36)
- A fourth pulley (35) that drives said third pulley (30) using a
second endless belt (37)
- a third motor (47) mounted on first side plate (4) transferring the
rotation to fourth pulley (35), and ultimately to said second pulley
15 (29) via third pulley (30) and first pulley (28) to second pulley (29)
which are connected through endless first and second belts (36,
37);
- a first guide rail (39) and a second guide rail (40) mounted on said
front plate (26) at its top and bottom position, respectively, and a
20 third guide rail (41) and fourth guide rail (42) mounted on said rear
plate (27), respectively exactly opposite to said first guide rail (39)
and second guide rail (40);
- a front protective cover (45) with swivel that covers a knife (48), a
pulley cover (58) to cover said first and second pulleys (28, 29),
25 wherein said cross cutter apparatus is mounted on a first side plate (4)
and a second side plate (5) via a first holding block (24) and a second
holding block (25) using mechanical means such as bolting, screwing or
welding.
19
6. The apparatus as claimed in claims 1 to 5, wherein said pulleys can be
round grooved pulleys having toothed or non-toothed profile that
accommodates respective belts (36, 37).
5 7. The apparatus as claimed in claims 1 to 6, wherein said belts (36, 37) are
flexible members have toothed profile that match those of respective
pulleys and they are selected from any of the types such as flat belts, V
belts, round belts, spring belts, multi groove belts, and timing belts, etc.
10 8. The apparatus as claimed in claims 1 to 7, wherein said movable knife
assembly (38) rotates in the orbit that is circumferential on the path of the
first endless belt (36) which runs over the first pulley (28) and second
pulley (29).
15 9. The apparatus as claimed in claims 1 to 8, wherein said guide rails (39, 40,
41, and 42) have u shape cross section or any other cross section such as v
shape, curve shape such that the movable knife assembly (38) moves
freely through it.
20 10. The apparatus as claimed in claims 1 to 9, wherein said front protective
cover (45) and swivel cover (46) are made of a sheet metal or plate bend to
form respective rigid bodies.
11. The apparatus as claimed in claims 1 to 10, wherein said movable knife
25 assembly (38) comprises:
- a knife (48) mounted on knife holding bracket (49) through a knife
holding plate (50) to position said knife (48) between said holding
bracket (49) and holding plate (50);
- A first guide pin (51) and a second guide pin (52) that are clamped
30 between a first side sheet (53) and a second side sheet (54) to form a
20
rigid body, wherein said first side sheet (53) and second side sheet
(54) are mounted on said knife holding bracket (49) that creates the
desired gap between both the sheets (53, 54) so that the swivel action
of guide pins (51, 52) occurs smoothly;
5 - a first opening (63) and a second opening (64) through which first
endless belt (36) is positioned such that the movement of the
movable knife assembly (38) is driven by said first endless belt (36).
12. The apparatus as claimed in claim 11, wherein said first side sheet (53)
10 and second side sheet (54) are constructed in the arc-shaped form so that
they can run on the circular periphery of the first pulley (28) and second
pulley (29).
13. The apparatus as claimed in claims 5 to 12, wherein the cutting speed of
15 said cross cutter apparatus (7) is set in such a way that time required by
said knife (48) to travel from a position A (59) on first longitudinal edge
(68) of fabric (2) to a position B (60) on the second longitudinal edge (69)
of said fabric (2) is same as the time required by the fabric (2) to travel the
distance between the position on said second longitudinal edge (9) that
20 corresponds to said position A to position B (60).
14. A method of cutting a moving web (2) of woven sheet material using
the apparatus as claimed in claims 1 to 13, characterised in that said
method comprises the following steps:
25 a. passing said web (2) through said web guide rollers (6, 6A, and 6B) to
maintain proper tension and removing shrinkage of the web (2);
b. pulling said web (2) through the post-draw roller assembly (11), said
pre-draw roller assembly (9), and said tension rollers assembly (13, 14)
and holding it down on said cutting platform (8) ready for cutting;
30 c. exiting said web (2) from said pre-draw roller assembly (9);
21
d. cutting said moving web (2) using said movable knife assembly (38)
having knife (48) held within said cross-cutter apparatus (7) when
said moving web (2) comes under said cross cutter apparatus (7)
mounted at an inclined angle with respect to the web movement axis
5 (57), while said moving web (2) is still held down securely by said
post-draw roller assembly (11) and pre draw roller assembly (9) to
provide proper tension and holding;
e. transferring the cut piece of said moving web (2) to a downstream
station for further processing as desired.
10
15. The method as claimed in claim 14, wherein the rotational speed of said
post-draw roller assembly (11) is slightly higher than the rotational speed
of the pre-draw roller assembly (11) and wherein the rotational speed of
said pre draw roller (9) is controlled by a first motor (10) and the rotational
15 speed of said post draw roller (11) is controlled by a second motor (12).
16. The method as claimed in claims 14 and 15, wherein the cutting speed of
said cross cutter apparatus (7) is set in such a way that time required by said
knife (48) to travel from a position A (59) on first longitudinal edge (68) of
20 fabric (2) to a position B (60) on the second longitudinal edge (69) of said
fabric (2) is same as the time required by the fabric (2) to travel the distance
between the position on said second longitudinal edge (9) that corresponds to
said position A to position B (60).