U.S. patent application number 10/541324 was filed with the patent office on 2006-05-11 for methods for the preparation of dhea derivatives.
This patent application is currently assigned to KOMORI-CHAMBON SA. Invention is credited to Christophe Clement, Pierre Simon.
Application Number | 20060096065 10/541324 |
Document ID | / |
Family ID | 32524774 |
Filed Date | 2006-05-11 |
United States Patent
Application |
20060096065 |
Kind Code |
A1 |
Simon; Pierre ; et
al. |
May 11, 2006 |
Methods for the preparation of dhea derivatives
Abstract
An apparatus for shaping a flexible web (2) includes, between an
entry roller (5) and a forming roller (3), a regulating module (7)
provided with a starting roller (13) designed to control the
movement and the speed of the web upstream of the shaping roller
(3) and at least one mobile guide element (9) designed to exert, at
least on one buffer loop (8) of the web (2) formed between the
rollers (5, 3), a positive guiding thereof, in accordance with a
law of displacement which is a function of the length of the buffer
loop (8) in operation.
Inventors: |
Simon; Pierre; (Orleans,
FR) ; Clement; Christophe; (Clery Saint Andre,
FR) |
Correspondence
Address: |
YOUNG & THOMPSON
745 SOUTH 23RD STREET
2ND FLOOR
ARLINGTON
VA
22202
US
|
Assignee: |
KOMORI-CHAMBON SA
Orleans
FR
|
Family ID: |
32524774 |
Appl. No.: |
10/541324 |
Filed: |
January 8, 2004 |
PCT Filed: |
January 8, 2004 |
PCT NO: |
PCT/FR04/00029 |
371 Date: |
June 30, 2005 |
Current U.S.
Class: |
19/163 |
Current CPC
Class: |
B65H 2515/31 20130101;
B65H 2403/5321 20130101; B65H 23/1882 20130101; B65H 2515/31
20130101; B65H 2406/111 20130101; B65H 2220/02 20130101; B65H
2555/13 20130101; B65H 23/188 20130101 |
Class at
Publication: |
019/163 |
International
Class: |
D01G 25/00 20060101
D01G025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 8, 2003 |
FR |
03/00179 |
Claims
1. Apparatus for shaping a web (2) made of a flexible material,
comprising at least one feed roll (5, 5') adapted to deliver the
web (2) continuously in accordance with a law of given displacement
(X.sub.e) and speed (V.sub.e), a shaping roll (3) associated with a
counterpart roll (3') adapted to shape the web over at least a part
of its peripheral length, this shaping roll being constituted by a
support roll (3a) on which at least one interchangeable shaping
element (3b) is added, fixed on its outer surface, and which is
animated by a movement of rotation in accordance with a law of
given displacement (X.sub.c) and speed (V.sub.c), characterized in
that it comprises, between the feed roll (5) and the shaping roll
(3), a regulating module (7) provided with take-off means (13, 13';
9, 9') adapted to control the displacement (X.sub.n) and the speed
(V.sub.n) of the web (1) upstream of the shaping roll (3) and at
least one mobile guide element (9, 9') adapted to exert on at least
one buffer loop (8) of the web (2) formed between said rolls (5,
3), a positive guiding of which the displacement is controlled in
accordance with a determined law.
2. Apparatus according to claim 1, characterized in that the law of
displacement of the mobile guide element (9, 9') of the web (2) is
a function of the law of displacement (X.sub.e) of the feed roll
(5, 5') and of the law of displacement (X.sub.n) of the take-off
means (13, 13'), itself a function of the law of displacement
(X.sub.c) of the shaping roll (3).
3. Apparatus according to claim 1, characterized in that the
take-off means are constituted by at least one roll (13, 13').
4. Apparatus according to claim 1, characterized in that the
take-off means are constituted by the mobile guide element (9), the
latter being formed by a rotating roll around which the web (2)
winds; at least one rotating roll (13, 13') animated by a
peripheral speed greater than that of the web (2) being disposed
between the shaping roll (3) and the guide roll (9).
5. Apparatus according to claim 2, characterized in that the guide
element (9) is constituted by a rotating roll around which the web
(2) winds.
6. Apparatus according to claim 2, characterized in that the guide
element (9) is constituted by a piece (9') fixed in rotation,
around which the web (2) winds.
7. Apparatus according to claim 6, characterized in that the guide
element (9') is provided with means for blowing a gas adapted to
create between itself and the web (2) a cushion of gas.
8. Apparatus according to claim 1, characterized in that the
displacement of the guide element (9, 9') is linear.
9. Apparatus according to claim 8, characterized in that the linear
displacement of the guide element (9, 9') is obtained by a linear
motor comprising primary and secondary poles mobile with respect to
each other and means for controlling their relative movements, the
guide element (9, 9') being fast with one of these poles.
10. Apparatus according to claim 8, characterized in that the
linear displacement of the guide element is obtained by a system
constituted by a connecting rod (10) articulated at one of its ends
on the latter and at its other end on a crank (12) whose angular
position determines the linear function of the guide element
(9').
11. Apparatus according to claim 1, characterized in that the
displacement of the guide element (9, 9') is circular.
12. Apparatus according to claim 11, characterized in that the
guide element is constituted by a guide roll (9) arranged so that
it is adapted, in the course of its displacement, to remain
tangential to another roll (24, 13), the web (2) being admitted
between these rolls (9, 24, 13) and winding around the latter in
order then to go in the direction of the shaping roll (3).
13. Apparatus according to claim 12, characterized in that said
other roll is constituted by a regulating roll (24).
14. Apparatus according to claim 12, characterized in that said
other roll is constituted by the take-off roll (13).
15. Apparatus according to claim 13, characterized in that the
circular displacement of the guide (9) and regulating (24) rolls
ensures control of position (X.sub.n) and of speed (V.sub.n) of the
web upstream of the shaping roll (3).
16. Apparatus according to claim 12, characterized in that the
guide roll (9) and said other roll are servo-controlled by each
other in rotation.
17. Apparatus according to claim 1, characterized in that it
comprises, between the feed roll (5) and the take-off means (13), a
system (11) for controlling the tension of the web.
18. Apparatus according to claim 17, characterized in that the feed
roll (5) is servo-controlled by the system for controlling the
tension of the web so as to ensure maintenance of the tension of
the latter at a constant value.
19. Apparatus according to claim 1, characterized in that it
comprises means adapted to read a cyclic mark disposed on the web,
to compare the position thereof with a reference of position of the
shaping roll and, as a function of this comparison, to modify the
positioning of the web with respect to the shaping roll.
Description
[0001] The present invention relates to an apparatus intended to
ensure shaping of a web made of a flexible material, such as in
particular a web of cardboard, from shaping rolls provided with
plates of which the format is variable and interchangeable.
[0002] It is known for example that, in the domain of rotary
cutting-out, the cut-out rolls as well as their associated control
pinions must be changed when it is desired to pass from one format
to another. Now, most of the time, these rolls are machined in the
mass, so that this operation of replacement is translated by a
particularly high cost.
[0003] In order to reduce this cost, it has been proposed to
produce cut-out rolls which are constituted by a support roll, on
the surface of which is fixed an interchangeable plate which is
provided with cut-out threads. Such a device allows a rapid
exchange and is translated by a reduced cost when one passes from
one plate to another. Such an exchange is thus effected without
problem, as long as the cut-out format remains unchanged from one
plate to the other.
[0004] However, when such is not the case, one is then obliged to
change the support roll as well as its accessory drive means.
[0005] The present invention has for its object to overcome such a
drawback by proposing a shaping apparatus provided with a
regulating module making it possible to use plate support rolls of
a constant diameter on which the user will fix, as a function of
his needs, work plates of diverse format, without it being
necessary for all that, when he will pass from one plate format to
another plate format, to exchange the support roll and its drive
means.
[0006] In other words, the present invention makes it possible for
the user to exchange only the shaping plates in order to pass from
a determined work format to another format, within the limit, of
course, of the peripheral length of the roll.
[0007] The present invention thus has for an object an apparatus
for shaping a web made of a flexible material, comprising at least
one feed roll adapted to deliver the web continuously in accordance
with a law of given displacement and speed, a shaping roll
associated with a counterpart roll adapted to shape the web over at
least a part of its peripheral length, this shaping roll being
constituted by a support roll on which at least one interchangeable
shaping element is added, fixed on its outer surface, and which is
animated by a movement of rotation in accordance with a law of
given displacement and speed, characterized in that it comprises,
between the feed roll and the shaping roll, a regulating module
provided with take-off means adapted to control the displacement
and the speed of the web upstream of the shaping roll and at least
one mobile guide element adapted to exert on at least one buffer
loop of the web formed between said rolls, a positive guiding of
which the displacement is controlled in accordance with a
determined law.
[0008] According to the invention, the law of displacement of the
mobile element for guiding the web will preferably be a function of
the law of displacement of the feed roll and of the law of
displacement of the take-off means, itself a function of the law of
displacement of the shaping roll.
[0009] The take-off means will preferably be constituted by at
least one roll.
[0010] The take-off means may also be constituted by the mobile
guide element, the latter being formed by a rotary roll around
which the web winds; at least one rotary roll animated by a
peripheral speed greater than that of the web being disposed
between the shaping roll and the guide roll.
[0011] The guide element may be constituted by a rotary roll, or by
a piece fixed in rotation, about which the web will wind.
Particularly when the guide element is constituted by an element
fixed in rotation, it may be provided with means for blowing a gas
adapted to create between itself and the web a cushion of gas.
[0012] The movement of displacement of the guide element may in
particular be linear or circular.
[0013] When the displacement is linear, it may be obtained by a
linear motor comprising primary and secondary poles mobile with
respect to each other and means for controlling their relative
movements, the guide element being fast with one of these poles.
This linear displacement of the guide element may also be obtained
by a system constituted by a connecting rod articulated at one of
its ends on the latter and at its other end on a crank whose
angular position will determine the linear function of the guide
element.
[0014] When the displacement is circular, the guide element will be
constituted by a guide roll arranged so that it is adapted, in the
course of its displacement, to remain tangential to another roll,
the web being admitted between these rolls and winding around the
latter in order then to go in the direction of the shaping
roll.
[0015] This other roll may be constituted by a regulating roll or
equally well by the take-off roll.
[0016] In order in particular to minimize the forces of friction
exerted on the web, the guide roll and the regulating roll may be
servo-controlled by each other in rotation, so that their
peripheral speeds are identical.
[0017] According to the invention, the circular displacement of the
guide and regulating rolls may ensure controlling of position and
of speed of the web upstream of the shaping roll. The apparatus
may, furthermore, comprise, between the feed roll and the take-off
roll, a system for controlling the tension of the web by which the
feed roll may be servo-controlled, so as to ensure maintenance of
the tension thereof at a constant value.
[0018] Finally, the apparatus may comprise means adapted to read a
cyclic mark disposed on the web, to compare the position thereof
with a position reference of the shaping roll and, as a function of
this comparison, to modify the positioning of the web with respect
to the shaping roll.
[0019] A form of embodiment of the present invention will be
described hereinafter by way of non-limiting example, with
reference to the accompanying drawing, in which:
[0020] FIG. 1 is a schematic view of a cut-out apparatus disposed
in a printing machine.
[0021] FIG. 1a is a schematic view of a variant embodiment of the
printing machine shown in FIG. 1.
[0022] FIG. 1b is a schematic view of a variant embodiment of a
guide element used in the apparatus according to the invention.
[0023] FIGS. 2a and 2b are partial schematic views showing cut-out
rolls in two respective positions, namely a first position
corresponding to the end of the cut-out phase and a second position
corresponding to the beginning of the cut-out phase.
[0024] FIG. 3 is a schematic view of a variant embodiment of a
shaping apparatus according to the invention.
[0025] FIG. 4a is a diagram respectively representing the speed of
feed of the web, the peripheral speed of the cut-out rolls, the
speed of feed of this web directly upstream of the cut-out rolls,
the speed of the roll of the regulating loop of the web, and this,
on the one hand, during the cut-out phase and, on the other hand,
during the end-of-cycle phase.
[0026] FIG. 4b is a diagram respectively representing the
positioning of the feed of the web, of the periphery of the cut-out
rolls, of the feed of this web directly upstream of the cut-out
rolls and of the roll of the regulating loop of the web, and this,
on the one hand, during the cut-out phase and, on the other hand,
during the end-of-cycle phase.
[0027] FIG. 5 is a diagram of the same type as that of FIG. 4a in a
form of embodiment of the present invention in which the speed of
feed of the web to be cut out varies in the course of a cut-out
cycle.
[0028] FIG. 6 is an example of a variant application of the shaping
apparatus according to the invention.
[0029] FIG. 7 is a schematic view of a variant making it possible
to constitute a regulating loop employed in an apparatus according
to the invention.
[0030] FIGS. 8 and 10 are schematic views of two other variant
embodiments of the apparatus shown in FIG. 7.
[0031] FIG. 9 is a schematic view of a variant embodiment of a
mobile guide element according to the invention.
[0032] FIG. 1 shows a shaping apparatus 1 of a printing machine,
intended to effect a cut-out operation. This shaping apparatus is
constituted by a cut-out roll 3 and its counterpart roll 3', which
are animated by a movement of rotation at a peripheral speed
V.sub.c, between which a web of cardboard 2 to be cut out is
admitted at a speed V.sub.n, this web 2 being delivered by a feed
roll 5 and its counterpart roll 5', at a peripheral speed
V.sub.e.
[0033] The cut-out roll 3 and its counterpart roll 3' are
constituted by a support roll 3a on which a shaping plate, for
example a cut-out plate 3b, is fixed. As a function of the work to
be carried out, this cut-out plate 3b may be more or less long, so
that it will occupy a more or less great part (p) of the total
periphery P of the cut-out roll 3.
[0034] Under these conditions, it will be understood that, unless a
considerable proportion of the web (equal to P-p/P) is wasted, it
is necessary to provide that, as soon as the cut-out phase is
ended, corresponding to the position of FIG. 2a, the web 2 be
stopped while the cut-out roll 3 and its counterpart roll 3'
determine their cycle of rotation (End-of-cycle phase). Moreover,
for the subsequent cut-out operation to be able to run normally, it
is also necessary that, at the moment of the beginning of the
following cut-out, and during the whole cut-out operation, the
speed V.sub.n of the web 2 occurring between the cut-out rolls be
the same as the peripheral speed of these latter, viz. V.sub.c,
this making it necessary to cause the web 2 to go back during the
end of the cycle for shaping the cut-out rolls 3, in order then to
return it forwards to communicate thereto the speed V.sub.n=V.sub.c
all along the cut-out.
[0035] It is for that purpose that a regulating module 7 has been
disposed between the feed rolls 5 and the cut-out rolls 3. This
regulating module makes it possible to produce a loop 8 forming
"buffer" and allows that part of the web 2 located just upstream of
the cut-out rolls 3 to stop, and even to move back, although the
feed rolls 5, 5' continue to feed the web 2 at a speed V.sub.e.
[0036] The regulating module 7 is constituted by a guide element,
here constituted by a guide roll 9, around which the web 2 winds,
and by a take-off roll 13 provided with a counterpart roll 13'
between which the web 2 is engaged. Unlike the "buffer" bands of
the prior state of the art, this band is thus guided positively,
i.e. it is maintained by an element whose position is determined
mechanically or electronically, so that the displacement of the
guide roll 9 is servo-controlled by the movement of displacement of
the loop 8 and more precisely by the length thereof, and not by an
element whose position is determined by the band itself, as is the
case, for example, when a pulley or a roll is in gravitational
abutment on the base of the band. It has been ascertained that such
an arrangement made it possible to attain much higher operational
speeds. The guide roll 9 is mounted to rotate about its shaft 14
and the latter is supported by a carriage 15 adapted to effect a
linear movement in a vertical direction perpendicular to the
horizontal direction of displacement of the web 2. The displacement
of the carriage 15 may in particular be ensured by a linear motor,
by a connecting rod/crank system, or by any other appropriate
mechanism. In the present form of embodiment, the take-off roll 13
and the feed roll 5 are disposed in such a manner with respect to
the guide roll 9 that the two web sections 2a located upstream and
downstream of the latter are parallel. FIG. 9 thus shows an example
of a means for linear displacement of a guide element 9' with the
aid of a system constituted by a connecting rod 10 articulated at
one of its ends on this guide element 9' and at its end on a crank
12 whose angular position determines that of the guide element
9'.
[0037] Of course, the guide roll 9 may be fixed in rotation or, as
shown in FIG. 1b, it may be other than a rotating roll and may be
formed by a fixed guide element 9', for example a semi-cylindrical
one.
[0038] FIGS. 4a and 4b respectively show, during a cycle of
rotation of the cut-out rolls 3, on the one hand, the diagram of
the speeds, and, on the other hand, the diagram of the relative
positions of the feed rolls 5 (viz. V.sub.e, X.sub.e), of the
cut-out rolls 3 (viz. V.sub.c, X.sub.c) of the web directly
upstream of the cut-out rolls 3 (viz. V.sub.n, X.sub.n) and of the
guide roll 9 (viz. V.sub.t, X.sub.t) and this for a plate element
3a whose length p represents 3/5 of the periphery P of the cut-out
rolls 3 (viz. p/P=0.6).
[0039] It is thus ascertained that the position X.sub.t and the
speed of vertical displacement V.sub.t of the guide roll 9 are
respectively a function of the positions X.sub.e, X.sub.n, on the
one hand, and of the speeds V.sub.e, V.sub.n on the other hand,
viz. X.sub.t=f(X.sub.e, X.sub.n) V.sub.t=f(V.sub.e, V.sub.n)
[0040] In the case of the form of embodiment shown in FIG. 1, and
since the sections 2a of the web 2 located upstream and downstream
of the guide roll 9 are parallel, the following will be had:
X.sub.t=(X.sub.e-X.sub.t)/2 V.sub.t=(V.sub.e-V.sub.n)/2 and the
carriage 15 will be animated by a movement which will be a function
of this law of displacement X.sub.t and of speed V.sub.t.
[0041] The present invention makes it possible to control the loop
8 which, due to the aerodynamic phenomena and the inertias, is
capable of disturbing, particularly at high speed, the advance of
the web 2 and its positioning, both in the longitudinal and
transverse direction, under the shaping plate.
[0042] Of course, according to the invention, the loop 8 may take
several configurations as a function of needs. For example, in the
variant embodiment shown partially in FIG. 1a, the sections 2a of
the web 2 located upstream and downstream of the guide roll 9 are
no longer parallel and their respective inclinations with respect
to the vertical are different. It will be understood that, in such
a configuration, the laws of displacement X.sub.t and of speed
V.sub.t of the guide roll 9 will, of course, be different from
those of the form of embodiment according to FIG. 1.
[0043] In another form of embodiment of the present invention,
which is shown in FIG. 3, the regulating loop 8 is located above
the web 2 and the guide roll 9 is located in the upper part of the
latter. Under these conditions, it will be understood that the
take-off roll 13 will be located above the web so as to effect a
correct return thereof, and, moreover, means for tensioning this
web have been provided, which are constituted by a tensioning
system 11 formed by a roll 16 mounted to rotate at the end of an
articulated connecting rod 17 about an axis O and which is in
abutment on the web 2. This system 11 is able to perform several
functions. Firstly, it makes it possible to maintain a virtually
constant tension of the loop 8 despite the accelerations imposed on
the web 2 during the operations. Secondly, it makes it possible to
absorb the small shifts in length which may affect the loop 8
during successive cut-out cycles. Finally, it makes it possible to
detect in simple manner, particularly by measuring the inclination
taken by the connecting rod 17, the moment when the accumulated
drifts of these shifts attain a critical threshold. Once this
detection is effected, servo-control means may then intervene,
particularly at the level of the feed roll 5, in order to ensure a
compensation in length of the loop 8 having the effect of returning
the connecting rod 17 of the tensioning system 11 to its normal
operational position.
[0044] Of course, such a regulation can be ensured by mechanisms
other than such systems and in particular by strain gauges which
might be disposed on the shafts of a guide roll.
[0045] In order to facilitate correct synchronism of the web 2 with
the cut-out roll 3 and its counterpart roll 3', a cyclic mark may
be made on the web 2, which will be synchronized with a determined
angular position of the cut-out plates. In this way, at each of the
cycles of rotation of the cut-out rolls 3, a comparison between the
position of this mark and the position of the cut-out plates 3b
will be made. If an error in positioning is detected, it will
provoke, via servo-control means, a reaction of the take-off roll
13 which will effect a correction of repositioning of the web
2.
[0046] The machine according to the invention may also be carried
out in configurations in which the speed of feed V.sub.e of the web
2 and/or the speed of rotation V.sub.c of the shaping rolls are not
constant.
[0047] It is thus ascertained in FIG. 4a that, during the first
phase, or cut-out phase, the peripheral speed V.sub.c of the
cut-out rolls 3 and the speed of feed V.sub.n of the web 2 at these
cut-out rolls which is ensured by the take-off roll 13, are equal,
which is, of course, necessary for a correct cut-out operation. It
is also ascertained in this Figure that the speed of feed V.sub.e
is different and constant, and thus remains so not only during the
cut-out phase but also during the end-of-cycle phase.
[0048] During the latter, which begins when the cut-out rolls 3 are
in the position shown in FIG. 2a, it is ascertained that the speed
V.sub.n of the web 2 decreases regularly, reverses, remains
constant during a short fraction of time, then re-accelerates in
the normal direction, to attain a speed V.sub.n=V.sub.c when the
following cut-out phase will begin, as shown in FIG. 2b.
[0049] FIG. 4b shows, during the two phases previously taken into
account, namely the cut-out phase and the end-of-cycle phase, the
linear positioning of the different elements. It is thus
ascertained that, during the first phase, or cut-out phase, the
linear positioning of the web and that of the periphery of the
cut-out plate, are identical, which is of course necessary for the
quality of the cut-out. It is then ascertained that, during the
second phase, or end-of-cycle phase, the inclination of the
straight line (speed) expressing X.sub.c, i.e. the positioning of
the points of the plate, remains constant and that, inversely, the
curve expressing X.sub.n varies, the inclination of this curve
decreasing in order then to increase, and it is also ascertained
that, at the end of end-of-cycle phase, the advance of the web at
the entry is equal to the advance of the web at the exit, this
being expressed by point A in FIG. 4b. It is also ascertained that,
at that point A, the tangent zz' to the curve X.sub.n is parallel
to the curve X.sub.c, which shows that, at the start of a new
cycle, the speed of the web which enters in the cut-out rolls 3 is
equal to the peripheral speed of the latter.
[0050] The apparatus according to the invention also makes it
possible to effect shaping of webs in which the entry speed V.sub.e
is variable in accordance with a well-determined specific law of
variation which is a function of the type of work effected. FIG. 5
thus shows the operational parameters of the apparatus, concerning
the positioning X.sub.c of the cut-out plates, of the web upstream
of the cut-out rolls X.sub.n (curve in broken lines), of the web at
the level of its feed X.sub.e and from which the positioning of the
guide roll 9 X.sub.t has been deduced.
[0051] The present form of embodiment makes it possible to place in
the same machine, and successively, two shaping apparatus of the
same period presenting a phase shift therebetween. FIG. 6 thus
shows an apparatus P.sub.1 of which it is seen that the cut-out
plates are located at the beginning of cut-out phase, and a second
apparatus P.sub.2 located upstream of the apparatus P.sub.1 and of
which it is seen that the cut-out rolls present a phase shift a
with respect to the cut-out roll of the apparatus P.sub.1. Thanks
to the regulating module 7, the present invention makes it possible
to compensate the phase shift of these two apparatus of the same
period.
[0052] The present invention also enables machines to be made,
comprising apparatus of different periods and, in addition,
presenting a phase shift.
[0053] The present invention also makes it possible to compensate
variations in the peripheral speed V.sub.c of the shaping rolls in
the course of the same shaping cycle, which variations make it
possible for example to minimize the accelerations of the web (by
the reduction of V.sub.c), by giving the latter more time to effect
its to and fro movement. In the event of the plate 3b being of
short length, it also makes it possible to increase this time the
peripheral speed V.sub.c during the end-of-cycle phase, this making
it possible to reduce the duration of the total cycle.
[0054] The present invention may, of course, be used with shaping
means other than cut-out means and might advantageously be applied
to fold-marking means, embossing means, stamping means, etc. . .
.
[0055] The displacement of the guide element 9 may be other than
linear, and in particular be circular. As schematically shown in
the form of embodiment of FIG. 7, the guide roll 9 is mounted on a
support sub-assembly 20, particularly constituted by two plates 21
connected in their upper part by a beam 23, this support being
mounted to move in rotation about a shaft 22. This shaft 22 also
constitutes the support of a regulating roll 24 which is tangential
to the guide roll 9. The web 2 is brought by the feed roll 5, abuts
on the regulating roll 24 in order then to be admitted between the
latter and the guide roll 9 around which it winds in order finally
to go towards the take-off roll 13, between which and its
counterpart roll 13' it is admitted. It will be understood that,
when the support 20 pivots about the shaft 22, so that the shaft 25
of the guide roll 9 follows the broken line C, the length of the
loop 8 increases or decreases depending on the direction of this
rotation. In order to minimize the friction between the web and the
rolls 9 and 24, these two rolls may be provided with means such as
gears ensuring their connection in rotation. The law of
displacement and of speed of the guide roll 9 will then be
determined in accordance with the arc of circle C.
[0056] The arrangement shown in FIG. 7 may be simplified
mechanically by attributing several functions to certain of the
rolls. FIG. 10 shows such an example of embodiment in which the
regulating roll 24 has been replaced by the take-off roll 13. The
counterpart roll 13' thereof is disposed above the latter. In this
configuration, it is understood that the roll 13 performs two
functions here, namely its function of take-off, as defined in the
preceding forms of embodiment, and the function performed
previously by the regulating roll 24. As in the form of embodiment
shown in FIG. 7, the regulating/take-off roll 13 and the guide roll
9 are disposed on a support 20 adapted to pivot about the shaft 22
merged with the axis of rotation of the regulating/take-off roll
13. As previously, when the support 20 pivots about shaft 22, so
that the shaft 25 of the guide roll 9 follows the broken line C,
the length of the loop 8 increases or decreases depending on the
direction of this rotation.
[0057] In the variant embodiment shown in FIG. 8, it is arranged
that the sub-assembly 20, besides its function of controlling
accumulation of the web 2, performs, in addition, a second
function, namely that performed previously by the take-off roll 13
and its counterpart roll 13', namely to ensure control of the web
upstream of the shaping roll 3. Such control will thus be obtained
by a more or less great oscillation.
[0058] According to the invention, it might also be possible to use
the guide roll 9 as take-off roll instead and in place of the rolls
13 and 13'. In such a modus operandi, it is the guide roll 9 which
performs the function of control of positioning X.sub.n and of
speed V.sub.n of the web 2 previously performed by the rolls 13 and
13'. In this modus operandi, the rolls 13 and 13' are in that case
animated by a speed of rotation giving them an overspeed with
respect to the web 2, with the result that they permanently slip
thereon.
* * * * *