U.S. patent application number 09/968021 was filed with the patent office on 2002-05-09 for device for precise connection for a machine for continuous unwinding.
Invention is credited to Dumas, Jean-Louis, Muller, Bernard.
Application Number | 20020053404 09/968021 |
Document ID | / |
Family ID | 26212650 |
Filed Date | 2002-05-09 |
United States Patent
Application |
20020053404 |
Kind Code |
A1 |
Muller, Bernard ; et
al. |
May 9, 2002 |
Device for precise connection for a machine for continuous
unwinding
Abstract
The present invention relates to a device for precise connection
for a continuous unrolling machine, comprising at least a means (3)
for unrolling two spools, a strip accumulator (4) and a device for
connecting ending strips (1) and new strips (2). Device
characterized in that the connection device is essentially
constituted by adjoining an indexing station (5) for the strips (1
and 2) and by at least one means (6, 37) for precise control of the
speed of movement of the strip through the joining and indexing
station (5). The invention is more particularly applicable to the
field of machines for continuously unrolling strip material, from
spools, to supply continuously printing machines, forwarding
machines or the like.
Inventors: |
Muller, Bernard;
(Drusenheim, FR) ; Dumas, Jean-Louis; (Guebwiller,
FR) |
Correspondence
Address: |
YOUNG & THOMPSON
745 SOUTH 23RD STREET 2ND FLOOR
ARLINGTON
VA
22202
|
Family ID: |
26212650 |
Appl. No.: |
09/968021 |
Filed: |
October 2, 2001 |
Current U.S.
Class: |
156/364 ;
156/505 |
Current CPC
Class: |
B65H 2601/325 20130101;
B65H 16/06 20130101; B65H 2301/41346 20130101; B65H 19/123
20130101 |
Class at
Publication: |
156/364 ;
156/505 |
International
Class: |
B65H 026/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 2, 2000 |
FR |
00 12534 |
Feb 9, 2001 |
FR |
00 01811 |
Claims
1. Precision connection device for a continuous unrolling machine,
comprising at least one means (3) for unrolling two spools, a strip
accumulator (4) and a device for connecting an ending strip (1) and
a new strip (2), characterized in that the connection device is
essentially constituted by adjoining an indexing station for the
strips (1 and 2) and by at least one means (6, 37) for precise
control of the speed of movement of the strip through the joining
and indexing station (5).
2. Device according to claim 1, characterized in that the joining
and indexing station (5) for the strips (1 and 2) is constituted by
two symmetrical assemblies (8) for preparing and cutting the ending
strip (1) and the new strip (2) and by a median bearing crosspiece
(9) for cutting the ending strip (1).
3. Device according to claim 2, characterized in that each assembly
(8) for preparing and cutting the ending strip (1) and new strip
(2) is constituted by a junction block (10) pivotable between a
preparatory position and a connecting position, by an indexing
device (11) for the new strip (2) and by means (12) for preparatory
cutting of said new strip (2).
4. Device according to claim 3, characterized in that each
pivotable junction block (10) is in the form of a casing which, on
the one hand, is connected to a pivoting lever (13) actuated by a
jack (14) articulated by its cylinder on the body of the machine
and, on the other hand, is provided with suction means (15) and
with a transverse bearing strip (16) for the new strip (2) during
preparatory cutting and for application of an adhesive strip on the
end, after said cutting.
5. Device according to claim 4, characterized in that each
pivotable junction block (10) is provided with a knife (24) for
cutting the ending strip (1), guided in a slot (25) and driven by a
jack.
6. Device according to claim 4, characterized in that each
pivotable junction block (10) is mounted on the body of the machine
for movement by means of a sliding bearing actuated by a jack for
movement in direction of the median bearing crosspiece (9).
7. Device according to claim 4, characterized in that the suction
means (15) consist in holes provided in a surface adjacent to the
transverse bearing strip (16) of the new strip (2), these holes
being arranged in groups symmetrical relative to the longitudinal
axis of the new strip (2) with suction chambers controlled
pairwise.
8. Device according to claim 3, characterized in that the
preparatory cutting means (12) for the new strip (2) is constituted
by a transverse support (17), mounted with the possibility of
retractable pivoting in bearings (18 and 19) on the body of the
machine and having a guide glideway (20) for a slider (21) bearing
a knife (22) loaded by a spring (23).
9. Device according to claim 3, characterized in that the cutting
means (12) is provided, at the free end of the transverse support
(17), with a hook or the like for holding it in retracted
position.
10. Device according to claim 3, characterized in that the device
(11) for indexing the new strip (2) is in the form of a return
roller (26) and a gripping roller (27), adapted to exert traction
on the new strip (2), and by an indexing means (28), such as a
magnifying glass or the like, mounted movably transversely to the
strip (2) on a support (29) removably fixed in a bearing (19) of
the body of the machine.
11. Device according to any one of claims 1 and 10, characterized
in that the body of the unrolling machine is provided respectively
at each device (11) for indexing the new strip (2) and in line with
the transverse bearing strip (16) of the new strip (2), in the
cutting position of this strip (2), with bearings (18 and 19) for
mounting the transverse support (17) constituting the preparatory
cutting means (12) for the new strip (2) and of the indexing means
(28).
12. Device according to claim 10, characterized in that the return
roller (26) is mounted in a sliding bearing (30) of the body of the
machine and is movable in the direction or opposite direction of
the corresponding gripping roller (27) by means of a mechanical or
electrical control, such as a jack, a motor reducer assembly or the
like.
13. Device according to claim 2, characterized in that the median
bearing crosspiece (9) for cutting the ending strip (1) is present
in the form of an anvil disposed between the pivotable junction
blocks (10) of each assembly (8) for preparation and cutting of the
ending strips (1) and new strips (2) and is provided with two
opposite transverse grooves (9') adapted to coact with the knife
(24) of each pivotable junction block (10).
14. Device according to claim 3, characterized in that each
assembly (8) for preparation and cutting of the ending strips (1)
and new strips (2) is completed by a punching device (31), mounted
on the body of the machine perpendicular to the anvil forming the
median bearing crosspiece (9) and coacting with a matrix (32)
provided on said anvil.
15. Device according to claim 14, characterized in that the
punching device (31) is constituted by a punch properly so-called
mounted at the end of a piston rod (33), in a guide chamber (34)
and provided with means (35) for application of the device against
the anvil during the punching operation.
16. Device according to claim 15, characterized in that the means
(35) for application of the device against the anvil is constituted
by a sleeve movable by the control jack of the punch and provided
with a resilient means (36) for compensating the final displacement
of the punch, in the form of a spring or the like.
17. Device according to claim 1, characterized in that the precise
control means for the speed of movement of the strip through the
joining and indexing station is constituted by a traction assembly
(37) for the ending strip (1) of variable speed, provided between
the strip accumulator (4) and the connecting device.
18. Device according to claim 17, characterized in that the
traction assembly (37) of the ending strip (1) of variable speed is
constituted by a return cylinder (38), over which passes the strip
(1), which is pressed against this cylinder (38) by means of a
pulley drive device (39).
19. Device according to claim 1, characterized in that a precise
control means for the speed of movement of the strip through the
joining and indexing station is constituted by a secondary
accumulation means (6) for the ending strip (1) disposed upstream
of the joining and indexing station (5).
20. Device according to claim 19, characterized in that the
secondary accumulation means (6) for the ending strip (1) disposed
upstream of the joining and indexing station (5) is present in the
form of two pairs of fixed return cylinders (40) disposed
symmetrically relative to the median bearing crosspiece (9), below
the assemblies (8) for preparation and cutting the ending strips
(1) and new strips (2), and two corresponding movable cylinders
(41) guided in movement relative to the fixed return cylinders (40)
by means of slideways (42) and jacks (43).
21. Device according to any one of claims 1, 17 and 19,
characterized in that the means (37 and 6) for precise control of
the speed of movement of the strip through the joining and indexing
station are combined by arrangement of these latter immediately
adjacent said joining and indexing station.
22. Device according to any one of claims 1 to 5, characterized in
that between the strip accumulator (4) and the joining and indexing
station (5) is provided an assembly (44) for detecting reference
marks (7) on the ending strip (1), which is disposed at a distance
from the knife (24) of the pivotable junction block (10) and
transverse opposed grooves (9') of the median bearing crosspiece
(9) corresponding to a whole number of sections between reference
marks (7).
23. Device according to claim 22, characterized in that the
detection assembly (44) is constituted by a pair of photoelectric
cells or the like.
Description
DESCRIPTION
[0001] The present invention relates to the field of machines for
continuously unrolling strip material, from spools, to supply
continuously printing machines, forwarding machines or the like,
and has for its object a device for precise connection for such a
continuously unrolling machine.
[0002] The precise connection between ending and new strips of
material is necessary in certain fields, so as to ensure a perfect
continuity of decorative or informative elements carried on said
strips. Such precision, which consists in obtaining a high
precision superposed connection, which is to say such that the
marks on an ending strip coincide perfectly with those marked on a
new strip, is particularly important, for example, in the case of
unrolling strips of the material in the form of aluminum films,
particularly for closing packages of medications or the like, which
bear inscriptions disposed at regular intervals. These inscriptions
thus require being perfectly offset relative to each other during
connection of two ends of the superposed strips, so as to guarantee
perfect agreement of the inscriptions with the contents of the
package. The same problems arise in the presence of other strips
provided with markings that are to be arranged in a perfectly
regular and precise manner.
[0003] At present, there is known from GB 2 148 856, an unrolling
machine using independent means for preparation of the end of the
new strip and for moving said strip so as to match a junction mark.
Such an embodiment however does not permit ensuring a sufficient
degree of precision.
[0004] There is also known, from U.S. Pat. No. 4,455,190, an
unwinder comprising a device for cutting the ending strip and
applying the beginning of the new strip on the end of the cut strip
provided with an adhesive, with overlap. The device according to
this document does not provide for indexing the strips, nor
referencing them, nor detecting position, nor means for moving the
strips at reduced speed, it is accordingly impossible to produce a
precise superposition and to obtain a sequence of the printing
between the two strips.
[0005] These known unwinding machines provide no means for moving
the strips at reduced speed under controlled tension, whereby they
do not permit producing a high precision connection, in particular
because of the inertia of the spool and/or the various changes in
strip tension, for example under the influence of motorized strip
drive. However, it is very important that the tension in the strip
remain constant, and hence that the elongation of the strip be
constant, to ensure precision of connecting the markings.
[0006] The present invention has for its object to overcome these
drawbacks by providing a precision connecting device for a
continuous unwinding machine permitting high precision of
superposed connection between two strips, ending and beginning,
with complete integrity of the spacing between consecutive
markings.
[0007] To this end, the precision connection device for a
continuous unrolling machine, comprising at least means for
unrolling two spools, a strip accumulator and a connecting device,
is characterized in that the connecting device is essentially
constituted by a station for joining and indexing the strips and by
at least one precise control means for the speed of movement of the
strip through the junction and indexing station.
[0008] The invention will be better understood from the following
description, which relates to a preferred embodiment, given by way
of non-limiting example and explained with reference to the
accompanying schematic drawings, in which:
[0009] FIG. 1 is a side elevational view of an unwinding machine
provided with a connection device according to the invention;
[0010] FIG. 2 is a fragmentary side elevational and cross-sectional
view, on a larger scale, showing the connection device and two
precise control means for the speed of movement of the strip;
[0011] FIG. 3 is a fragmentary side elevational view, on a larger
scale, of a station for preparing a new strip;
[0012] FIG. 4 is a fragmentary front elevational view of the strip
and the drive of the ending strip;
[0013] FIG. 5 is a schematic side elevational view showing the
principle of operation of the machine;
[0014] FIGS. 6 and 7 are views on a larger scale analogous to that
of FIG. 5, showing two modes for preparation of a new strip;
[0015] FIG. 8 is a view partially in cross-section, on a large
scale, showing the junction of two registering strips;
[0016] FIGS. 9a to 9c are partial schematic views showing the
operation of the strip accumulator, and
[0017] FIG. 10 is a curve of the speeds of strips during the
connection operation.
[0018] FIGS. 1, 2 and 5 of the accompanying drawings show a
continuous unrolling machine permitting continuously unrolling with
superposed connection between two strips, an ending strip 1 and a
new strip 2 and comprising at least one means 3 for unrolling two
spools, a strip accumulator 4 and a connection device.
[0019] According to the invention, the connection device is
essentially constituted a station for joining and indexing the
strips 1 and 2 and by at least one means 6, 37 for precise control
of the speed of movement of the strip through the joining and
indexing station.
[0020] The unrolling machine according to the invention is
essentially adapted for unwinding spools of paper, aluminum or
films of other material, so as to obtain a superposed high
precision connection as shown in FIG. 8 of the accompanying
drawings. To this end, it is a matter of obtaining a perfect
coincidence between the marks 7 provided respectively on the ending
strip 1 and the new strip 2. Thus, the sections comprised between
the markings 7 of the strips 1 and 2 will be joined if it is only a
matter of a single and same strip and the supply of the machine
disposed downstream will be maintained without interruption and
without risk of offset of the sections. The connection of the new
strip 2 to the ending strip 1 must be carried out without
modification of the speed of supply to the downstream machine.
[0021] This object is achieved by the use of the joining and
indexing station 5 for the strips 1 and 2 and at least one means 6,
37 for precise control of the speed of movement of the strip
through the joining and indexing station.
[0022] According to a characteristic of the invention, the joining
and indexing station 5 of the strips 1 and 2 is constituted by two
symmetrical assemblies 8 for preparation and cutting the ending
strip 1 and the new strip 2 and by an intermediate bearing
crosspiece 9 for cutting the ending strip 1 (FIGS. 2, 4 and 5).
[0023] Each assembly 8 for preparing and cutting the ending strip 1
and the new strip 2 is preferably constituted by a junction block
10 pivotable between a preparatory position, shown at the left in
FIGS. 2 and 5 and in FIG. 3, and a connecting position shown at the
right of FIGS. 2 and 5 and in FIG. 4, by an indexing device 11 for
the new strip 2 and by a means 12 for preparatory cutting of the
new strip 2. It is thus possible to position precisely the new
strip 2 and to prepare its end adapted to be joined overlappingly
with the corresponding end of the ending strip 1.
[0024] Each pivotable junction block 10 is, as shown more
particularly in FIGS. 2 and 3 of the accompanying drawings, in the
form of a casing which, on the one hand, is connected to a pivoting
lever 13 actuated by a jack 14 articulated by its cylinder on the
body of the machine and, on the other hand, is provided with
suction means 15 and a transverse bearing strip 16 for the new
strip 2 during the preparatory cut and the application of an
adhesive strip on the end, after said cut. Thus, the new strip 2
can be perfectly maintained on the pivotable block 10 during all
the operation of preparation of its beginning and its end can be
cut precisely to receive an adhesive strip.
[0025] Moreover, each pivotable junction block 10 is provided with
a knife 24 for cutting the ending strip 1, guided in a slot 25 and
driven by a jack (not shown).
[0026] Moreover, each pivotable junction block 10 is mounted on the
body of the unrolling machine by means of a sliding bearing, not
shown, actuated by a jack (not shown) for movement in direction of
the intermediate bearing crosspiece 9. Such a mounting permits
placing the junction block 10 against the crosspiece 9 during
cutting of the ending band 1.
[0027] The suction means 15 consists in holes provided in a surface
adjacent to the transverse strip 16 for bearing against the new
strip 2, these holes being preferably arranged in groups
symmetrical relative to the longitudinal axis of the new strip 2
and with suction chambers controlled pair-wise. In a known manner,
each suction chamber is connected to a central suction means by
means of manual control valves. As a result, each block 10 can be
adapted as a function of the width of the strips to be
prepared.
[0028] The preparatory cutting means 12 for the new strip 2 is
constituted by a transverse support 17, mounted with the
possibility of retractable pivoting in bearings 18 and 19 of the
frame of the machine and having a guide slideway 20 for a slider 21
bearing a knife 22 loaded by a spring 23. This cutting means 12 is
preferably provided at the free end of the transverse support 17,
with a hook or the like, not shown, for holding it in retracted
position.
[0029] The device 11 for indexing the new strip 2 is in the form of
a return roller 26 and of a gripping roller 27, adapted to exert
traction on the new strip 2, and with indexing means 28, such as a
magnifying glass or the like, mounted movably transversely to the
strip 2 on a support 29, removably fixed in a bearing 19 on the
chassis of the machine. This bearing 19 can be released by
pivotable retraction of the transverse support 17 constituting the
preparatory cutting means 12 for the new strip 2.
[0030] Preferably, the body of the unrolling machine is provided
respectively at the level of each indexing device 11 for the new
strip 2 and in line with the bearing strip 16 of the new strip 2,
in the cutting position of this strip 2, with bearings 18 and 19
for mounting the transverse support 17 constituting the preparatory
cutting means 12 for the new strip 2 and for the indexing means
28.
[0031] Thus, these two elements can easily be emplaced and moved as
needed.
[0032] According to another characteristic of the invention and as
shown in FIG. 3 of the accompanying drawings, the return roller 26
is mounted in a sliding bearing 30 on the body of the machine and
is movable in the direction of, or in the opposite direction of,
the corresponding gripping roller 27 by means of mechanical or
electrical control, such as a jack, a motor reducer assembly or the
like. Another embodiment permits, when the reference marks 7 of a
new strip 2 are turned toward the center of the spool, moving the
return roller 26 relative to the gripping roller 27 by the distance
necessary such that a whole number of sections between the
reference marks 7 will be located between the indexing means 28 and
the position of the cut. As a result, the return roller 26 can be
adjusted into different positions relative to the gripping roller
27. Each of these positions corresponds to one format of the strip.
These positions are referenced relative to the body of the machine,
so as to facilitate preparation.
[0033] The intermediate bearing crosspiece 9 for cutting the end of
the strip 1 (FIGS. 2, 4 and 5) is preferably present in the form of
an anvil disposed between the pivotable junction blocks 10 of each
assembly 8 for preparation and cutting of the ending strips 1 and
new strips 2 and is provided with two opposite transverse grooves
9' adapted to coact with the knife 24 of each pivotable junction
block 10.
[0034] According to another characteristic of the invention, and as
shown in FIG. 4 of the accompanying drawings, each assembly 8 for
preparation and cutting the ending strips 1 and new strips 2 is
completed by a punching device 31, mounted on the body of the
machine perpendicular to the anvil forming the medial bearing
crosspiece 9 and coacting with a matrix 32 provided on said anvil.
This punching device 31 is constituted by a punch properly
so-called mounted at the end of a piston rod 33 in a guide chamber
34 and provided with means 35 for applying the device against the
anvil during the punching operation. This application means 35 of
the device against the anvil is preferably constituted by a sleeve
movable by the control jack for the punch and provided with a
resilient means 36 for compensating the final displacement of the
punch, in the form of a spring or the like. Thus, the punch is
first moved toward the anvil and the means 35 is applied against
this latter, then the punching of the strip is effected during
final movement of the control jack.
[0035] The strip accumulator 4 is of known type and is adapted to
accumulate a reserve of strip to ensure continuous supply at
constant speed to the downstream machine, when the strips 1 and 2
are stopped for connection. The detour rods in the accumulator 4
can move relative to each other thanks to a jack and occupy open
positions, working positions and closed positions, as well as any
other intermediate positions.
[0036] According to another characteristic of the invention and as
shown in FIGS. 1, 2 and 5 of the accompanying drawings, a means 37
for the precise control of the speed of movement of the strip
through the joining and indexing station can be constituted by a
traction assembly 37 for the ending strip 1, at variable speed,
provided between the strip accumulator 4 and the connection device.
Such an assembly can be constituted by a return cylinder 38, over
which passes the strip 1, which is pressed against this cylinder 38
by means of a pulley drive device 39. Such a pulley drive device 39
is of known type, requiring no further detailed description and
permits controlling the speed of movement of the ending strip 1
through the joining and indexing station 5 of the strips 1 and
2.
[0037] The means for precise control of the speed of movement of
the strip in the joining and indexing station can also be
constituted by a secondary accumulation means 6 for the ending
strip 1 disposed upstream the joining and indexing station 5. Such
a secondary accumulation means 6 of the ending strip 1 (FIGS. 1, 2,
5 and 9) can be present in the form of two pairs of fixed return
cylinders 40 disposed symmetrically relative to the median bearing
crosspiece 9, below the assemblies 8 for preparing and cutting the
endings strips 1 and the new strips 2, and by two corresponding
movable cylinders 41 guided in movement relative to the fixed
return cylinders 40 by means of slideways 42 and jacks 43. This
secondary accumulation means 6 permits creating a small reserve of
strip and delivering it thereafter at low speed and under constant
tension, during the connecting operation, such that the connecting
position may be predetermined with precision.
[0038] It is also possible, according to another characteristic of
the invention, to combine the means 37 and 6 for precise control of
the speed of movement of the strip through the joining and indexing
station, by arrangement of these latter immediately adjacent the
joining and indexing station. Thus, the movement of the ending
strip 1 is subject to a double control of its speed of movement,
permitting perfect positioning of the connecting reference
marks.
[0039] Moreover, there is provided, between the strip accumulator 4
and the joining and indexing station 5, an assembly 44 for
detecting reference marks 7 of the ending strip 1, which is
disposed at a distance from the knife 24 of the pivotable junction
block 10 and from the opposed transverse grooves 9' of the median
bearing crosspiece 9 corresponding to a whole number of sections
between reference marks 7. Such a detection assembly 44 can
preferably be constituted by a pair of photoelectric cells or the
like.
[0040] The unrolling machine according to the present invention
operates in the following manner:
[0041] After placing a new spool 2 in replacement on the spindle
whose axis of rotation is free, the corresponding junction block 10
is moved such that the transverse bearing strip 16 of the new strip
2 and the suction means 15 will be easily accessible to the
operator.
[0042] As a function of the position of the reference marks 7 on
the strip, which is to say according to where they are located on
the surface oriented toward the center of the spool, as shown in
FIG. 6, or toward the exterior of the spool (FIG. 7), the return
roller 26 will be moved relative to the gripping roller 27 by the
necessary distance, as explained above.
[0043] In the first case, the indexing means 28, for example in the
form of a magnifying lens, for the indexing device 11 of the new
strip 2, is disposed between the return roller 26 and the gripping
roller 27. The operator can then, by looking through the magnifying
glass constituting the indexing means 28 and by turning the
gripping roller 27, advance the strip 2 until the reference mark 7
coincides perfectly with an index of said magnifying lens 28. In
this position, there is a whole number of sections between
reference marks 7 between the magnifying glass 28 and the position
of the cut, with which exactly and perfectly coincides a reference
mark 7. Thus the strip 2 of the new spool is perfectly indexed.
[0044] After the indexing operation, the strip 2 is immobilized
against the bearing transverse strip 16 of the junction block 10 by
actuating suction means 15. The strip 2 is then cut with the help
of the knife 22 and the end of the cut strip is withdrawn. Then a
strip of double face adhesive is stuck to the end of the strip
2.
[0045] The junction block 10 is then moved into the connection
position, as shown in FIG. 2 at the right, and the strip 2 is
tensioned by rotating the spool in the reverse direction to the
normal unrolling direction so as to obtain optimum tension in the
strip, then the strip is immobilized in known manner on its
spindle. As a modification, it is also possible to control the
tension of the strip with the help of a tension detector or by
subjection to the drive of said spindle.
[0046] When the reference marks 7 are turned outwardly of the spool
it is not necessary to move the return roller 26 relative to the
format of the sections between the reference marks 7. The strip 2
is threaded in the same manner as when the reference marks 7 are
turned toward the center of the spool and the indexing means 28 of
the index device 11 of the new strip 2 is placed such that it will
be at the level of the means 12 for preparatory cutting of the new
strip 2 (see FIG. 7). The movement of the strip 2 is effected in a
manner identical to that described above. The same is true as to
the other successive operations.
[0047] The connection cycle is explained more particularly with
respect to FIGS. 9 and 10. Thus, in fifteen regions Z1 to Z15,
there is given:
[0048] VA=linear speed of movement of the ending strip 1 of the
first spool, upstream of the secondary accumulation means 6
[0049] VB=linear speed of unwinding of the new strip 2 from the
second spool, upstream of the secondary accumulation means 6
[0050] VC=linear velocity of the strip, downstream of the joining
and indexing station.
[0051] In the region Z1, the spool A unrolls with a speed
VA=V2=nominal speed of operation=speed of the machine to be
supplied and the traction assembly 37 for the ending strip 1 also
turns at the speed VC=V2. The strip accumulator 4 is in working
position, which is to say almost closed and the means 37 and/or 6
for precise control of the speed of movement of the strip are in
the rest condition. The new spool is installed and the end of the
strip B is prepared.
[0052] In the region Z2, there is detected the next end of the
first spool A, whilst the strip accumulator 4 is in the position of
FIGS. 9a or 9b.
[0053] In the region Z3, the strip accumulator 4 is filled by
spacing, in known manner, the deflecting bars from each other by
means of a jack. Simultaneously, the connection cycle is triggered
by acceleration of the speed VC, then VA follows VC up to VS.
[0054] In the region Z4, VC and VA are held constant at speed V5
and the strip accumulator 4 is full.
[0055] In the region Z5, the strip accumulator 4 being empty, VC
and VA are reduced to V2.
[0056] In the region Z6 the means 37 and/or 6 for precise control
of the speed of movement of the strip are actuated. VC remains
constant and VA increases to V3.
[0057] In region Z7, after actuation of the means 37 and/or 6 for
precise control of the speed of movement of the strip, VA returns
to speed V2.
[0058] In region Z8, VC is braked until it stops, VA follows and
the ending strip 1 is stopped. The corresponding spool is blocked
against rotation. Strip accumulator 4 progressively empties by
supplying the downstream machine at nominal speed V2.
[0059] In region Z9, VC is slightly accelerated up to V1, which is
a very low speed, the ending strip moves at a very low speed, under
the effect of the operation of means 37 and/or 6 for precise
control of the speed of movement of the strip and the reference
marks 7 are sought on the strip 1 by the detection assembly 44.
When the reference mark 7 of the strip 1 coincides with the
photoelectric cells or the like of the assembly 44, VC stops. In
this position, the reference mark 7 of the strip 1 coincides with
the reference mark 7 of the new strip 2, which was previously
indexed in region Z1. Thus, to guarantee high precision connection,
it is necessary to move the strip 1 at a low speed and under
constant tension. This is obtained by the means 37 and/or 6 for
precise control of the speed of movement of the strip, operated
independently or in combination, which permit delivering the strip
1 at low speed and under constant tension.
[0060] In region Z10, VC=VA=VB=0, the strips are stopped and their
respective reference marks 7 are in perfect correspondence. The
strip 1 is cut with the knife 24 and the anvil 9 and simultaneously
the end of the strip 2 is glued to the end of the strip 1, in
superposition, sa shown in FIG. 8.
[0061] In the region Z11, the new spool is freed for rotation. VC
is accelerated up to V2 and VD follows.
[0062] In region Z12, VB=VC=the nominal speed of operation.
[0063] In region Z13, the position of the strip accumulator 4 is
detected (see FIGS. 9a, b, c). If the latter is too closed, it is
opened more by simultaneously accelerating VC to reach the working
position of the accumulator; conversely, if it is too open, it is
closed and simultaneously VC is slowed.
[0064] In the region Z14 the ending spool is withdrawn.
[0065] In the region Z15, the new spool unrolls to replace the
ending spool; the cycle can recommence as in region Z1.
[0066] Thanks to the invention, it is possible to provide an
unrolling machine permitting unrolling two spools and their
superposed connection with perfect indexing of the new strip
relative to the ending strip.
[0067] Of course, the invention is not limited to the embodiment
described and shown in the accompanying drawings. Modifications
remain possible, particularly as to the construction of the various
elements or by substitution of technical equivalents, without
thereby departing from the scope of protection of the
invention.
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