[0001] The invention relates generally to apparatus for splicing flexible materials, such
as webs, and the like. More particularly, the invention concerns an apparatus for
splicing a leading end of a first web with a trailing end of a second web to form
a new continuous web under high speed operating conditions and without the necessity
of frequent interruption of the web conveyance process.
[0002] Apparatus for splicing flexible material, such as web, are well known in the art.
In a typical apparatus and method for forming butt joints between webs or flexible
material the webs are cut while in an overlapping relations to form abutting ends.
One end of one of the webs is separated while being conveyed so that the two cut ends
to be joined are in abutting relations with one another. Then, splice tape is applied
to the abutting ends to form the butt joint. A problem with existing web butt splicers
of the type described is that precise splicing at high web velocity, and with thin
webs often produces unsatisfactory joints.
[0003] US-A-4,363,695 discloses one such device for splicing together rolls of web. The
device includes means for accelerating a new stockroll of film up to the speed of
an expiring web while discarding the potentially damaged outer convolutions of the
webs. Splicing tape is applied to overlapping end portions of the webs in a rolling
motion by entrapping air bubbles between the splicing tape and the webs to be joined
so as to avoid weakening the splice.
[0004] Other representative devices for splicing web include those disclosed in US-A-3,939,031;
US-A-3,654,035; and US-A-3,717,057 and US-A-4,234,365, each of which generally describes
devices that attempt to accelerate a new web stockroll (N') to match the velocity
of an expiring web (E')over 180 degrees of rotation of a cutting drum (D') having
cutting member (C') (Refer to prior art illustration in Fig. 1). It is our belief
that the aforementioned devices are not capable of efficient operations at very high
web velocities (that is, greater than about 100 ft./min.) because there is such a
limited time to accelerate a large web stockroll without the necessity of a film reserve
device positioned between the stockroll and the splicer or between the splicer and
the continuous downstream process. A further shortcoming of the above-identified type
splicing devices is that they require that a new web stockroll be loaded onto a turreting
unwind as illustrated, for instance in US-A-3,717,057, US-A-4,492,609 and US-A-4,097,323.
Alternatively, prior art devices use a non-driven, displaceable unwind such that the
new web is always presented to the splicing apparatus in one and only one position.
[0005] The aforementioned shortcomings presented by existing splicing apparatus are solved
with an important feature of our device wherein a fresh web is alternately presented
to the splicing apparatus in either of two positions in the conveyance process. This
capability eliminates the need for space consuming and costly turreted unwinds, taught
in the above references. Also, this novel feature of the present invention is especially
useful with webs having light sensitive emulsion coatings or which require a high
degree of cleanliness in that it enables the use of web stockroll delivery systems
using closed cassettes such as the one described in US-A-5,193,759, hereby incorporated
herein by reference. An obvious advantage of closed cassettes is that they house and
protect the sensitive webs from light and dust damage and the like. Moreover, since
closed cassettes provide limited access to the film, the use of additional devices,
such as turrets and displaceable unwinds, is precluded.
[0006] Therefore, there persists a need for an efficient web butt-splicer capable of operating
at high web speeds in an environment substantially free of contaminants, such as damaging
dust and light, and which does not require frequent downtime associated with changing
web feed stockrolls.
[0007] An object of the present invention is, for example, to provide an apparatus for splicing
abutting ends of webs substantially free of a gap or overlap.
[0008] Another object of the present invention is, for example, to provide an apparatus
for alternatingly feeding rolls of webs into one of two conveyance arrangements and
ultimately splicing just-cut ends of both webs without having to interrupt the conveyance
process.
[0009] It is a feature of the invention that a just cut trailing end of an expiring web
is moved into abutting alignment with a fresh cut lead end of a fresh web where the
two ends of the webs are joined without interrupting the conveyance process.
[0010] To accomplish these and other objects and advantages of the invention, there is provided,
in one aspect of the invention, an apparatus for splicing a first, expiring web to
a second, fresh web, comprising a first, ported, full circumference vacuum drum and
a second, ported, full circumference vacuum drum which is capable of being urged toward
the first drum. Further, the apparatus includes means for supplying the expiring web
to one of the first and second vacuum drums as well as means for supplying the fresh
web to another of the first and second vacuum drums. With respect to both webs at
the end of a splicing cycle (defined below), the first and second vacuum drums are
enabled to transport in alternating sequence the other of the expired and fresh webs.
Additionally, a first cutting member is mounted on one of the first and second vacuum
drums in a portion of a circumference of the drum where vacuum is applied. Similarly,
a second cutting member is mounted on the other of the first and second vacuums drums
in a portion of a circumference of the drum where vacuum is applied. The cutting members
are capable of cooperating with one another for cutting the webs. Still further, the
apparatus includes a third, full circumference vacuum drum and a fourth, at least
partial circumference vacuum drum. Means for applying a first strip of splice tape
to the fourth drum is also provided. Moreover, means are provided for moving the first
and second drums into proximity to cause the first and second cutting members to cooperate
for cutting the first and second webs between the first and second drums, so that
a just-cut leading end of the expiring web remains with one of the first and second
vacuum drums and a just-cut trailing end of the fresh web remains with the other of
the first and second vacuum drums. Also, means for moving the first and third vacuum
drums into proximity is provided.
[0011] The splicing apparatus also includes means cooperating with the moving means, as
described above, for causing a just-cut trailing end of the expiring web and a just-cut
leading end of the fresh web to transfer from the first drum to the third drum. Finally,
this embodiment of the invention includes means for moving the third and fourth drums
into proximity to cause the first strip of splice tape to be applied across the trailing
end of the expiring web and leading end of the fresh web, to form a spliced web.
[0012] In another aspect of the invention, a method of butt-joining webs comprises the steps
of providing elements including a first and second vacuum drum for supporting the
web and providing first and second cutting members, each being mounted on the first
and second vacuum drums, respectively, in a portion of the circumference where vacuum
is applied, each element as described above. Further, the step of supplying an expiring
web to one of the first and second vacuum drums and supplying a fresh web to another
of the first and second drum is included in the invention. The first and second drums
are moved into proximity to cause the first and second cutting members to cooperate
to form a just-cut leading end and a just-cut trailing end of the webs. Moreover,
the trailing end of the just cut expiring web and the leading end of the just cut
fresh web are moved in abutting alignment for subsequent joining. Splicing tape is
provided for engageably joining the ends of the webs into abutting alignment. The
just-cut leading end of the expiring web, and alternately the just cut trailing end
of the fresh web are deflected away from the splicing tape so as to provide easy access
to one side of the ends of the webs to be joined. Then, a first strip of splice tape
is applied across one side of the trailing end of the expiring web and the leading
end of the fresh web thereby forming a spliced web.
[0013] The foregoing and other objectives, features and advantages of the invention will
be apparent from the following more particular description of the preferred embodiments
of the invention, as illustrated in the accompanying drawings:
Figure 1 is a front elevation view of a prior art splicing apparatus;
Figure 2 is a side elevation view of the apparatus of the invention;
Figure 3 is a side elevation view of the apparatus showing the upper drum assemblage
and lower drum assemblage in cooperating relations for splicing;
Figure 4 is a side elevation view of the apparatus showing its position after a first
splicing sequence;
Figure 5 is a side elevation view of the apparatus prior to initating the second splicing
sequence. Web stockroll 30 is about to expire.
Figure 6 is a side elevation view of the apparatus showing it position after a scond
splicing sequence.
Figure 7 is a side elevation view of the apparatus showing its position after a second
splicing sequence.
Figure 8 is an isomeric view of an adhesive tape dispensing apparatus adapted for
use with the invention;
Figure 9 is a diagrammatic side elevation view of the ported vacuum drums;
Figure 10 is a timing diagram showing the sequencing of the ported chambers in the
vacuum drums of Fig. 9;
Figs. 11and 12 are side elevation views showing the just-cut web ends in different
sequence;
Fig. 13-14 are cross-sectional views of the abutted spliced joint formed during two
different cycles;
Fig. 15 is an side elevation view of the valve porting arrangement; and,
Fig. 16 is an elevational end view of the rotary valve arrangement for governing the
sequencing of vacuum and air porting shown in Fig. 15.
[0014] Turning now to the drawings, and particularly to Figs. 2-4, the apparatus, or web
butt-splicer,
10, as claimed in the principles of the invention is illustrated. Broadly defined the
apparatus
10 for splicing a first, expiring web
47 to a second, fresh web
48, comprises first and second, ported, full circumference vacuum drums
21,
20. Means for supplying the expiring web
47 to one of the first and second vacuum drums
21,
20 is provided. Also, means for supplying the fresh web
48 to another of the first and second vacuum drums
21,
20 is provided. In this embodiment, the expiring web
47 and fresh web
48 are sequentially transported by one of the first and second vacuum drums
21,
20 at the end of a splicing cycle, as described below.
[0015] A first cutting member, or knife,
42, is mounted on one of the first and second vacuum drums
21,
20 in a portion of a circumference of the drum where vacuum is applied. Likewise, a
second cutting member, or counter-knife,
40, capable of cooperating with the first cutting member
42 is mounted on the other of the first and second vacuum drums
21,
20 in a portion of a circumference of the drum where vacuum is applied. Moreover, third,
at least partial circumference and fourth, full circumference vacuum drums
32,
33 are provided. Further, means for applying a first strip of splice tape to the fourth
drum
33 and means for moving the first and second drums
21,
20 into proximity to cause the first and second cutting members
42,
40 to cooperate for cutting the first and second webs
47,
48 between the first and second drums
21,
20. In this way, a just-cut leading end
47a of the expiring web
47 remains with one of the first and second vacuum drums
21,
20 and a just-cut trailing end
48a of the fresh web
48 remains with the other of the first and second vacuum drums
21,
20. Further, means are provided for causing a just-cut trailing end
47b of the expiring web
47 and a just-cut leading end
48b of the fresh web
48 to transfer from drum
21,
20 to drum
33, shown in Fig. 11. The apparatus
10 also includes means for moving the third and fourth drums
32,
33 into proximity to cause the first strip of splice tape to be applied across the trailing
end of the expiring web
47 and leading end of the fresh web
48, to form a spliced web.
[0016] According to Figure 2, a first web supply stockroll
31 delivers web to a continuous running process and is guided through the splicing apparatus
over web supports
25 and
26. Figure 4 depicts a second web supply stockroll
30 delivering web to the continuous running process and is guided through the splicing
apparatus over web supports
28 and
26. Web support
25 and idler roller
23 are independently attached to thread-up guide
27. Thread-up guide
27 is arranged to pivot about the center of web support
28 for urging idler roller
23 alternately into engagement with stationary idler roller
22 and idler roller
29. When thread-up guide
27 is engaged with stationary idler roller
22, threading of a new web supply stockroll
30 around drum
20 is enabled. On the other hand, when thread-up guide
27 is engaged with idler roller
29, threading of a new web supply stockroll
31 around drum
21 is enabled.
[0017] As shown in Figs 3 & 4, drums
20,
32 and
34, or first drum triad, are preferably belted together for rotating in a counterclockwise
direction at a common peripheral velocity. Similarly, drums
21,
33 and
35, or second drum triad, mounted for transalational movement, as described below, are
preferably belted together for rotating in a clockwise direction at a common peripheral
velocity substantially equal to that of drums
20,
32 and
34. A person of ordinary skill in the art will appreciate, however, that it is within
the contemplation of the invention that peripheral velocities of the drums may vary
and that the velocity of drums
20,
32 and
34 may be greater than or less than the velocity of drums
21,
33 and
35. When the first and second drum triads reaches a peripheral velocity equal to that
the linear velocity of the expiring web, a cam actuated linear actuator
46 displaces block
45 supporting drums
21,
33 and
35 toward stationary drums
20,
32 and
34. According to Fig. 3, the upward displacement of block
45 is synchronized with the rotation of the vacuum drums
21,
33 and
35 such that the expiring web
47 does not contact drum
35 until after adhesive tape segment
44 has rotated pass its engagement point with the expiring web
47. This sequence of events can be achieved with a timing sequence such as the one illustrated
in Fig. 10 which shows the operations of the various components of the invention as
well as vacuum and air ports. The rotational positions of the first and second drum
triads are synchronized such that first cutting member, or knife,
42 cooperates with second cutting member, or counter knife,
40, to sever both the new and expiring webs
48,
47 at a common longitudinal position. By advancing the just-cut ends of webs
47,
48 from the contact point of drums
20 and
21 to the contact point of drums
32 and
33, drum
32 rotates splice tape segment
43 into contact with the upper surface of the two webs
47,
48 to apply a first segment of splice tape, centered over the just-cut ends of the new
and expiring webs
47,
48. Also, by advancing the just spliced web ends from the contact point between drums
32 and
33 to the contact point between drums
34 and
35, drum
35 rotates splice tape
44 into abutment with the underside of the new and expiring webs
47,
48, centered on their freshly joined ends.
[0018] The rotational positions of the first and second drum triads are further synchronized
with the downward displacement of the linear actuator
46 such that support block
45 begins to separate drums
21,
33 and
35 from drums
20,
32 and
34 when drums
21,
33 and
35 are in the angular positions depicted in Figure 3. In this position, a full revolution
of drums
21,
33 and
35, after contacting drums
20,
32, and
34, results in drums
20 and
21 separating an amount sufficient to prevent knife
42 and counter knife
40 from cooperatively engaging one another and thereby cutting the two webs
47,
48 a second time.
[0019] Referring again to Figs. 2,3,4 and 9, drum
20 (Fig. 2)is automatically fed web from a first web supply stockroll
30 in cooperation with stationary idler roller
22 and movable idler roller
23 such that the web end is acquired by drum
20 about a portion of its periphery through the aid of vacuum ports
0,
1,
2 and
3 (Fig. 9). The web enters an upper scrap chute
24 (Figs. 2-4) and remains in this position until a splice is requested. At this time,
the new stockroll
30 is accelerated to match the web speed of expiring web
47 through vacuum assisted frictional contact with driven drum
20. This removes the potentially damaged outer convolutions of web from stockroll
30 and discards them into first scrap chute
24. When fresh web
48 reaches the same velocity as expiring web
47, the lower triad of drums is brought into contact with the upper drum triad, the
drums being in the angular positions shown in Figure 2 at the time of contact. An
additional 80 degrees of rotation of drums
20 and
21 will bring knife and counter-knife
42 and
40 into facing alignment to sever both webs
47,
48 and thus create four just-cut web ends. Two of the web ends will be discarded and
two web ends will be joined in butted alignment, as described above. Separating the
two web ends to be discarded from the two web ends to be joined at high speed is accomplished
by porting vacuum and compressed air to strategic segments of the various drums at
the proper times. This is achieved according to a timing diagram (Fig. 10) and through,
for instance, a rotary valve
60 (Fig. 15) having aligned, spatially separated stationary and rotating disks
62,
64, as shown more clearly in Fig. 16. In Fig. 16, stationary disk
62 comprises at least one opening
66 for communicating air and vacuum to various ports. Further, rotating disk
64 includes at least one arcurate recess
70 communicating with sources of vacuum or compress air (not shown). Vacuum ports 6
and
7 in drum
21 will be ported to a vacuum source just before severing the webs in order to acquire
the just-cut leading end of expiring web
47 and divert it around drum
21 into second scrap chute
41. Simultaneously, the freshly cut trailing end of new web
48 continues around drum
20 and into first scrap chute
24. The just-cut lead end of web
48 continues around drum
20 until reaching port 2 which has been ported to compressed air instead of vacuum at
the moment the webs were cut. An air blast transfers the lead end of new web
48 from drum
20 to a portion of drum
33 supplied with vacuum from vacuum port
10 across a narrow gap shown in Fig. 11.
[0020] After the two scrap web ends are removed, as described above, the just-cut trailing
end
47b of web
47 and the just-cut leading end
48b of web
48 are brought into butted alignment against the surface of drum
33. A segment of splicing tape carried on drum
32 is brought into rolling contact with the two webs
47,
48, centered longitudinally across one side of the just-cut web ends to form a spliced
web illustrated in Figs. 13 and 14. Optionally, a second segment of splicing tape
carried on drum
35 may be brought into rolling contact with the underside of the two webs, centered
longitudinally across the just-cut spliced web ends (Figs. 13 and 14). Those skilled
in the art will appreciate that various means of transferring tape to drums
35,
32 may be used. I prefer using a tape transfer device
44a having transportable tape
44 and cutting member
43'(Fig. 8), as described in USP 5,053,096, hereby incorporated herein by reference.
As soon as the second segment of splice tape has been applied, the lower drum triad
begins to move away from the upper triad and thread-up chute
27 begins to rotate toward idler roller
29 to deflect expiring web
47 out of the straight line path of the new web
48 across web supports
28 and
26 (Fig. 3). The vacuum drums continue to rotate in the open position, that is, with
first and second triad separated from one another, until all of expiring web
47 has been removed from the core of stockroll
31 and eliminated through scrap chute
41.
[0021] In a similar manner, referring again to Figs. 4, 5, 6 and 8, drum
21 is automatically fed web from a second web supply stockroll
31 in cooperation with stationary idler roller
29 and movable idler roller
23. In this configuration, the web end is acquired by drum
21 about a portion of its periphery through the aid of vacuum ports
5, 6,and
7. The web enters a lower scrap chute
41 and remains in this position until a splice is requested. At this time, the new stockroll
31 is accelerated to match the web speed of the expiring web
48 through vacuum assisted frictional contact with driven drum
21. This removes the potentially damaged outer convolutions of web from stockroll
31 and discards them into second scrap chute
41. When the new web
47 reaches the same velocity as expiring web
48, the lower triad of drums is brought into contact with the upper triad, the drums
being in the angular positions shown in Figure 5 at the time of contact. An additional
80 degrees of rotation of drums
20 and
21 will bring knifes
40 and
42 into facing alignment to sever both webs and thus create four freshly cut web ends.
Two web segments will be discarded and two web ends will be joined in butted alignment.
Vacuum ports
1,
2,and
3 in drum
20 will be ported to a vacuum source just before severing the webs in order to acquire
the just-cut leading end of expiring web
48 and divert it around drum
20 into scrap chute
24. Simultaneously, the freshly cut trailing end of new web
47 continues around drum
21 and into scrap chute
41. Vacuum port 6 in drum
21 will be ported to a source of compressed air just before severing the webs in order
to divert the freshly cut leading end of new web
47 away from drum
21 toward the contact point between drums
20 and
33. We have found that an auxiliary source of compressed air or a film guide
49 is preferred at high speeds with very thin and flexible webs in order to reliably
divert the film end away from drum
21 and onto the vacuum ported periphery of drum
33 in butted alignment with the just-cut trailing end of expiring web
48 (Fig. 12). Thereafter, a segment of splicing tape carried on drum
32 is brought into rolling contact with the two webs, centered longitudinally across
the freshly cut web ends. Similarly, a second segment of splicing tape carried on
drum
35 may be brought into rolling contact with the underside of the two webs, centered
longitudinally across the freshly spliced ends (Figs. 13-14). As soon as the second
segment of splice tape has been applied, the second drum triad begins to move away
from the first drum triad and thread-up chute
27 begins to rotate toward idler roller
22 to deflect expired web
48 out of the straight line path of the new web
47 across web supports
25 and
26 (Fig. 6). The vacuum drums continue to rotate in the open position until all of expired
web
48 has been removed from the core of stockroll
30 and eliminated through scrap chute
24.
[0022] In operations, referring to Figs. 1-3, & 8, during thread-up of a new web stockroll
30, vacuum ports
0,
1,
2, and
3 are supplied with vacuum to acquire a free end of the fresh web
47. When the expired web
48 and fresh web
47 are cut, vacuum ports
6 and
7 of vacuum drum
21 are ported to vacuum (by a valve arrangement of the type shown in Fig. 14) to adhere
the just-cut leading end of the expiring web
48 to vacuum drum
21 and thus divert it into a scrap chute
41 while vacuum port
2 is switched to compressed air to divert the just-cut leading end of the fresh web
47 onto drum
33. The just-cut trailing end of the fresh web
47 adheres to vacuum drum
20 and follows it into a scrap chute
24. The just-cut trailing end of the expiring web bends around vacuum drum
20 and continues onto vacuum drum
33 (Fig. 12) where splice tape
43 is applied, joining it to the just-cut lead end of the fresh web
47 thereby forming an web butt-splice. Vacuum drum
35 applies a second length of tape
44 to the opposite side of the web butt splice (Fig. 14). After the splice, ports
5,
6, and
7 are supplied with vacuum to enable drum 21 to pull the core waste off of the right
stockroll.
[0023] Vacuum ports
4,
8,
9,
10,
11,
12,
13, and
14 are not needed at low speeds and become useful only at higher web speeds, for example,
web speeds greater than about 400 ft./min.
[0024] Referring again to Figs. 5-7 and 9, during thread-up of a new stockroll, ports
5,
6, and
7 are supplied with vacuum to acquire and accelerate the new web end. When the webs
are cut, ports
6 and
7 remain ported to vacuum to retain the freshly cut trailing end of the new web and
channel it into a waste chute
41. Ports
1,
2 and
3 are supplied with vacuum in order to retain the freshly cut lead end of the expiring
end and divert it into a second scrap chute
24. The just-cut lead end of the new web
48 must be diverted to follow drum
20 instead of its otherwise straight line path generally toward the center of drum
33 by a blast of air from port
9 or by a diverting chute
49. The just cut trailing end of the expiring web
48 bends around drum
20 and continues onto drum
33 where splicing tape
43 is applied, joining it to the just-cut lead end of the new web
47. Drum 6 applies a second length of tape to the opposite side of the splice. After
the splice has been accomplished, ports
0,
1,
2 and
3 are supplied with vacuum to enable drum
20 to pull the core waste web off of the left stockroll.
- 10
- apparatus, or web butt-splicing apparatus
- 30, 31
- alternatingly fresh or expired web stockroll
- 25
- roller supporting web 47
- 47
- alternatingly fresh and expiring webs
- 48
- alternatingly expiring and fresh web
- 26
- exit roller supporting webs 47 and 48
- 28
- roller supporting web 48
- 22
- stationary idler roller
- 29
- stationary idler roller
- 23
- idler roller cooperates with idlers 22,29
- 27
- thread-up guide
- 21, 33, 35
- displaceable vacuum drum arrangement supporting expiring web 47
- 20, 32. 3
- 4 fixed vacuum drum arrangement supporting fresh web 48
- 46
- cam actuated linear actuator for displacing block 45
- 45
- support block for vacuum drums 21, 33, 35
- 5,6,7, 8
- vacuum ports of drum 21
- 0,1,2,3,4
- vacuum ports in drum 20
- 9,10, 11
- vacuum ports in drum 33
- 12,13,14
- vacuum ports in drum 34
- 40,42
- cutting members or knives
- 41
- second scrap chute
- 43
- splice tape segment on drum 32
- 24
- first scrap chute
- 44
- splice tape segment on drum 35
- 49
- film or web guide
- 60
- rotary valve
- 62
- stationary disk
- 64
- rotating disk
- 66
- opening
- 70
- recess
- 44a
- tape transfer device
- 431
- cutting member
1. Apparatus for splicing a first, expiring web to a second,
fresh web, comprising:a first, ported, full circumference vacuum drum;
a second, ported, full circumference vacuum drum;
means for supplying the expiring web to one of the first and second vacuum drums;
means for supplying the fresh web to another of the first and second vacuum drums,
the expiring web and fresh web being further transportable by either one of the first
and second vacuum drums in alternating sequence after the webs are spliced;
a first cutting member mounted on one of the first and second vacuum drums in a portion
of a circumference of the drum where vacuum is applied;
a second cutting member capable of cooperating with the first cutting member, the
second cutting member being mounted on the other of the first and second vacuum drums
in a portion of a circumference of the drum where vacuum is applied;
a third, full circumference vacuum drum;
a fourth, at least partial circumference vacuum drum;
means for applying a first strip of splice tape to the fourth drum;
means for moving the first and second drums into proximity to cause the first and
second cutting members to cooperate for cutting the first and second webs between
the first and second drums, so that a just-cut leading end of the expiring web remains
with one of the first and second vacuum drums and a just-cut trailing end of the fresh
web remains with the other of the first and second vacuum drums
means for moving the first and third vacuum drums into proximity;
means cooperating with the moving means for causing a just-cut trailing end of
the expiring web and a just-cut leading end of the fresh web to transfer from the
first drum to the third drum; and
means for moving the third and fourth drums into proximity to cause the first strip
of splice tape to be applied across the trailing end of the expiring web and leading
end of tile fresh web, to form a spliced web
2. Apparatus as claimed in Claim 1, further comprising:
a fifth vacuum drum; and
means for moving the third and fifth vacuum drums into proximity to cause the
spliced web to move from the third to the fifth vacuum drum, thereby isolating application
of the first tape strip from tension transients downstream of the fifth vacuum drum.
3. Apparatus as claimed in Claim 3, further comprising:
a sixth, at least partial circumference vacuum drum;
means for applying a second strip of splice tape to the sixth drum; and
means for moving the fifth and sixth drums into proximity to cause the second strip
of splice tape to be applied across the trailing end of the expiring web and leading
end of the fresh web opposite the first strip.
4. Apparatus as claimed in Claim 1, further comprising means for rotating the other of
the first and second vacuum drums before they are moved into proximity, to remove
outer convolutions from a stockroll of the fresh web.
5. Apparatus as claimed in Claim 1, further comprising means for rotating the one of
the first and second vacuum drums after they have been moved from proximity following
splicing, to remove a remaining portion of the expiring web from a stockroll.
6. The apparatus recited in Claim 1 wherein the means for supplying the fresh web and
the expiring web to one of the first or second vacuum drums comprises a corresponding
arrangement of support rollers and idler rollers positioned relative to one another
so as to enable the webs to follow a substantially, fully extended path to the drums.
7. A method of butt-joining webs, comprising the steps of:
providing a first and second vacuum drum for supporting the web;
providing first and second cutting members, each being mounted on the first and
second vacuum drums, respectively, in a portion of the circumference where vacuum
is applied;
supplying an expiring web to on of the first and second vacuum drums;
supplying a fresh web to another of the first and second drum;
moving the first and second drums into proximity to cause the first and second
cutting members to cooperate to form a just-cut leading end and a just-cut trailing
end of the webs; and,
moving the trailing end of the just-cut expiring web and the leading end of the
just-cut fresh web in abutting alignment for subsequent joining;
providing splicing tape for engageably joining the ends of the webs in abutting
alignment;
deflecting the just cut leading end of the expiring web, and alternately deflecting
the just cut trailing end of the fresh web, the respective ends of the webs being
deflected away from the splicing tape so as to provide easy access to one side of
the ends of the webs to be joined;
applying a first strip of splice tape across one side of the trailing end of the
expiring web and the leading end of the fresh web thereby forming a spliced web..
8. The method recited in Claim 7 further comprising the step of deflecting the just-cut
trailing end of the fresh web, and alternately deflecting the just-cut leading end
of the expiring web, so as to provide easy access to an opposite side of the ends
of the webs to be joined.
9. The method recited in Claim 7 further comprising the step of applying a strip of tape
to the opposite side of the ends of the web.
10. The method recited in Claim 7 wherein the step of deflecting comprises moving the
just-cut trailing end of the fresh web by vacuum porting on one of the first and second
drums.